ENETS Guidelines

Neuroendocrinology 2009;90:167–183 Received: August 27, 2008

Accepted after revision: October 24, 2008
DOI: 10.1159/000184855
Published online: August 28, 2009

ENETS Consensus Guidelines for the

Standards of Care in Neuroendocrine
Tumors: Radiological Examinations
Anders Sundin a Marie-Pierre Vullierme b Gregory Kaltsas c
Ursula Plöckinger d and all other Mallorca Consensus Conference participants
a
Department of Radiology, Uppsala University Hospital, Uppsala, Sweden; b Service de Gastroentérologie,
Hôpital Beaujon, Clichy, France; c G. Genimatas Hospital, Athens, Greece; d Department of Hepatology and
Gastroenterology, Campus Virchow-Klinikum, Charité-Universitätsmedizin Berlin, Berlin, Germany

Introduction These distinct features in tumor growth, secretory ca-

pacity and localisation are consequently reflected in the
In contrast to other common types of malignant tu- wide variation in clinical presentation of different NETs.
mors, the vast majority of gastroenteropancreatic [endo- Moreover, a number of NETs may be found incidentally
crine pancreatic (EPTs) and carcinoid] neuroendocrine when patients undergo surgery for unrelated reasons or
tumors (NETs) are well differentiated and slowly growing may be an unexpected finding in the histopathological
with only a minority showing an aggressive behavior. specimen as with appendiceal carcinoids. Accordingly,
NETs can produce a variety of metabolically active sub- the need for diagnostic procedures and the choice of im-
stances (hormones and amines) leading to distinct clini- aging methods varies considerably depending on the pa-
cal syndromes (functioning tumors). However, the ma- tient’s tumor status at presentation.
jority are non-functioning and present either with local- The various aspects to consider in the choice of imag-
ly advanced disease giving rise to site-specific symptoms ing methods are related to primary tumor detection,
or distant metastases mainly to the liver. Patients with evaluation of its local extent and relation to adjacent an-
midgut carcinoid tumors and liver metastases may expe- atomical structures, staging of the tumor concerning re-
rience symptoms of the carcinoid syndrome (flushing gional and distant metastases, evaluation of tumor so-
and diarrhoea), and develop carcinoid heart disease. In matostatin receptor density, therapy monitoring and de-
such patients, mesenteric involvement may lead to isch- tection of recurrent disease. In this review, the various
aemia and/or intestinal obstruction due to a surrounding applications of current radiological modalities are de-
desmoplastic reaction with kinking of the bowel and vas- scribed, including computed tomography (CT), magnet-
cular encasement. Approximately 30–40% of these pa- ic resonance imaging (MRI), ultrasonography (US), con-
tients may require emergency surgery and are diagnosed trast-enhanced US (CEUS), endoscopic US (EUS) and
at a relatively early stage before liver metastases have oc- intraoperative US (IOUS). The corresponding applica-
curred. tions of nuclear medicine procedures are presented sepa-
rately.
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© 2009 S. Karger AG, Basel Anders Sundin

Simon Fraser University

0028–3835/09/0902–0167$26.00/0 Department of Radiology

Fax +41 61 306 12 34 Karolinska University Hospital
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E-Mail karger@karger.ch Accessible online at: SE–171 76 Stockholm (Sweden)

www.karger.com www.karger.com/nen Tel. +46 707 999 621, E-Mail anders.sundin@ki.se
 Materials and Methods may be examined during one breath hold. These thin,
detailed images may be reformatted in any chosen ana-
The participants of the consensus meeting considered the use
of various radiological methods for the different imaging applica-
tomical plane, usually in coronal and sagittal views. The
tions in relation to documented available figures on sensitivity images allow reconstruction in three-dimensional (3D)
and specificity together with the expertise of the participants; volumes and can be rotated to better appreciate anatomy
availability of the various modalities was also taken into account. and pathological findings. Importantly, as opposed to
Further aspects considered were patient preparation and infor- previous incremental CT scanning, the development of
mation, clinical information communicated to the radiologist for
optimisation of the examination procedure and imaging inter-
the fast MDCT technique allows considerably better use
pretation, imaging protocols, reporting of results and radiation of i.v. CM and CT imaging can now be performed in sev-
dose administered to the patient. The use of intravenous (i.v.) con- eral contrast-enhancement phases, i.e. early arterial (or
trast media (CM) for CT in patients with impaired renal function CT angiography), the late arterial (or portal-venous in-
and in subjects with previous experience of side effects by i.v. CM flow) and the venous contrast-enhancement phase.
was also addressed.
In general, data from the literature regarding the sensitivity
MDCT has therefore developed as one of the basic tech-
and specificity of the various radiological modalities used for the niques for oncological imaging including NETs.
diagnosis of NETs suffer from the small number of patients in-
cluded and the absence of a reliable gold standard for verification Sensitivity, Specificity and Detection Rate
of the imaging results. Quite frequently, detection rate is reported The CT-acquired sensitivity, specificity and detection
instead of sensitivity and specificity. Results are sometimes based
on a patient-by-patient analysis and in other reports the results
rate (mean and range based on the number of patients
are also, or instead, lesion-by-lesion based. The detection rate and studies) for various NETs is presented in table 1.
merely states the proportion of patients with disease that is de- In 5 studies on 162 patients, CT showed a mean 73%
tected by the imaging method out of all examined subjects. The (range 63–82%) sensitivity and 96% (range 83–100%)
sensitivity is instead calculated with reference to a gold standard specificity for diagnosing an EPT [1–5]. The mean detec-
and equals the proportion of patients with the disease detected by
the imaging method out of all patients with the disease according
tion rate for EPTs of a further 6 studies including 178 pa-
to the gold standard [sensitivity = true positive observations/(true tients was 73% (range 39–94%) [6–11]. Based on these 11
positive observations + false negative observations)]. This review studies that included 343 EPT patients the mean sensitiv-
includes imaging data on sensitivity and specificity on a patient- ity and detection rate for an EPT was 73%, although with
by-patient basis. Detection rates are instead based on lesion-by- a considerably wide variation (39–94%), but a generally
lesion analyses and report the proportion positive imaging results
in patients with biochemically/clinically evident NETs. Also, the
high specificity (mean 96%).
studies that were considered used current standards of imaging. In 4 studies reporting on the detection of NET liver
Thus, studies in which incremental CT was performed, those metastases in 135 patients the mean sensitivity was 82%
without adequate contrast enhancement, and studies that utilised (range 78–100%) whereas the mean specificity was 92%
low field strength MRI (!0.5 T) were excluded. range (83–100%) [12–15]. In a single study including 21
The current presentation, on radiological imaging of NETs,
was adapted to the layout of the template for the whole consensus patients, the detection rate was 81% [11]. Four studies
document and is divided into paragraphs according to the various evaluating the presence of extrahepatic soft tissue metas-
radiological imaging techniques. tases in 77 patients showed a 75% mean sensitivity (range
63–90%) and 99% specificity (98–100%) [12–15]. Another
similar study on 21 patients reported 81% detection rate
Results [15]. Three reports on imaging of various NET metastases
in the abdomen and thorax included 164 patients and
Computed Tomography showed a mean sensitivity of 83% (range 61–100%) and
Modern spiral or helical CT, generally multidetector specificity of 76% (range 71–80%) [13, 16, 17]. The detec-
CT (MDCT) scanners are available in most radiology de- tion rate in a similar study including 25 patients was 76%
partments and CT has currently replaced several imag- [11].
ing applications for which earlier other imaging modali- CT enteroclysis showed a 50% sensitivity and 25%
ties were employed, such as plain film radiography and specificity in 8 patients with NETs compared to capsule
angiography. By utilising several parallel detector rows, endoscopy where the corresponding figures were 38 and
in recent generations of CT scanners at least 64 detector 100%, respectively [18]. In 219 patients with small bowel
rows and with a tube rotation time of 0.3–0.5 s, hundreds tumors, CT enteroclysis showed a sensitivity and speci-
or more of 1-mm or sub-millimetre transaxial images are ficity of 85 and 97%, respectively, and 19 of these tumors
acquired per second and the whole abdomen and thorax were carcinoids [19].
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Table 1. CT diagnosis of NETs

Type of NET Sensitivity Specificity Detection rate Number of Reference

mean (range) mean (range) mean (range) patients/studies

Endocrine pancreatic tumor 73% (63–82) 96% (83–100) 162/5 1–5

73% (39–94) 178/6 6–11
Liver metastases 82% (78–100) 92% (83–100) 135/4 12–15
81% 21/1 11
Extrahepatic abdominal soft tissue metastases 75% (63–90) 99% (98–100) 77/4 12–15
81% 21/1 15
Various NET lesions in abdomen and thorax 83% (61–100) 76% (71–80) 164/3 13, 16, 17
76% 25/1 11
Small bowel NET at CT enteroclysis 50% 25% 8/1 18
85% 97% 219a/1 19

Data in the literature on the sensitivity, specificity and detection rate for NET diagnosis by CT.
a Out of 219 patients included in the study there were 19 subjects with carcinoids.

Hard- and Software Requirements with diazepam. When CM administration is required via
For CT of the abdomen, thorax and neck, the CT scan- an i.v. catheter, this may lead to a feeling of warmth. The
ner should allow spiral examinations, optimally by presence of a previous history of renal impairment and
MDCT, and should be able to reconstruct at a minimum i.v. CM-related adverse reactions, whether this was sys-
^3-mm and optimally ^1-mm images. The high spatial temic or localised, should be checked. In the presence of
resolution of the thin slices is needed for optimal exami- previous adverse effects the contrast material responsible
nation especially of the pancreas, liver and neck. A high should be investigated since side effects experienced with
temporal resolution is also needed in order to perform older ionic high-osmolar preparations are rare with mod-
examinations during contrast enhancement for abdomi- ern non-ionic and low-osmolar CM.
nal CT angiography, and the various contrast-enhance- Fluids but no solid food are recommended during
ment phases required for proper examination of the liver 12 h before the examination. In patients with impaired
and pancreas. renal function it is of particular importance to inform the
The software needed for image reconstruction and patient that he or she needs to be well-hydrated before the
image reformats for multiplanar reconstructed images examination in order to reduce the risk of CM-related
and maximum intensity projections are generally sup- renal adverse effects.
plied with the CT scanner but specialised image refor- Information on the radiation dose is generally not nec-
matting with volume rendering technique and virtual en- essary for the patient. It should be documented on the im-
doscopy may need additional software programs. aging report, according to local regulatory authorities.

Patient Information Patient Preparation

For better patient cooperation and examination re- Patients who have experienced a severe CM-related re-
sults, the patient should be well informed and properly action by modern non-ionic and low-osmolar CM are
prepared. Patients should receive information according- pretreated with oral antihistaminic drugs and glucocor-
ly; the examination generally takes !15 min. For abdom- ticoids according to local expertise. Medications should
inal CT, patients need to arrive at the department 2 h in start 13–16 h before the contrast-enhanced CT examina-
advance for filling of the bowel by drinking up to 800 ml tion; for urgent procedures the i.v. route is preferred.
of fluid (generally tap water). Then patients are placed on Also, the type of CM responsible for a previous or cur-
the examination bed and moved into a short tunnel, i.e. rent CM-related reaction should, if this information is
the CT gantry, where claustrophobic patients may be- available, be documented in the radiological report. Fur-
come symptomatic and should be adequately prepared ther use of this particular CM may then be avoided since
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the CM-related side effect is related to the specific CM or CO2 as for CT examination for suspected colonic car-
molecule, and not to iodine in general. cinoma.
Diabetic patients treated with metformin should stop
the drug the day before, or at the latest, the same day as Information Is Provided by the Clinician
the CM administration and have serum creatinine In order to perform a proper CT examination and to
checked before restarting metformin. Although serum decrease potential risks, it is necessary that the clinician
creatinine is routinely used, it should be interpreted with provide adequate information. This includes the precise
caution in the elderly and smaller patients; in such cases diagnosis, current medical therapy, previous surgery, and
creatinine clearance can be used instead (normally 1 40 information regarding the presence of diabetes, renal im-
ml/min). A serum creatinine 6130 ␮mol/l puts patients pairment and previous CM-related adverse reactions.
at risk for renal impairment; in such cases hydration with The results of previous imaging examinations are man-
at least 1 litre of fluid before and after CM is adminis- datory.
trated. When serum creatinine is 1180 ␮mol/l, CT ex-
amination is generally performed without i.v. contrast Imaging Technique
enhancement. The imaging protocols used for CT of the abdomen,
As an aid, various computer software is available to including the liver and pancreas, thorax and neck vary
make an estimation of the creatinine clearance by using according to the local experience and routines. Given
the patient’s serum creatinine, weight, age and sex as in- that the previously recommended hardware require-
put parameters according to the formula: ments are taken into consideration and that bolus-track-
Estimated creatinine clearance = ing technique is available, various examination protocols
{k ⴢ [(140 – age) ⴢ weight in kg]/serum creatinine in ␮mol/l} , usually result in equally good examinations. Conse-
quently, this consensus document is focused on basic ex-
where k is a constant which is 1.23 for men and 1.04 for amination parameters, instead of detailed protocols, and
women [20]. important general imaging aspects are discussed.
Data on the possible benefits of i.v. iodixanol as a CM Currently, MDCT of the abdomen, thorax and neck is
in patients with renal impairment is still not convincing. performed using 4 ! 2.5- to 64 ! 0.6-mm detectors in
For filling of the bowel, patients generally drink 800 4- and 64-channel MDCT scanners, respectively. A pitch
ml of tap water during 2 h before the CT examination of of 1.25–1.5 is recommended. The pitch is the table move-
the abdomen. About 20 ml of CM (300–400 mg/ml) may ment per tube rotation divided by the width of the total
be added to the tap water. However, for CT examination number of the detectors used. The resulting 1- to 3-mm
of the pancreas or when duodenal disease is suspected, transaxial images should preferably be reformatted in 2-
the duodenum needs to be filled with water without ad- to 3-mm multiplanar reconstructed images, the coronal
dition of CM. This is best achieved when the patient and the sagittal planes using a 1/3 to 1/2 overlap to fa-
drinks the last 150–200 ml of water a few minutes before cilitate reading and especially image presentation at clin-
CT examination. It is usually sufficient to start filling of ical conferences.
the bowel an hour before CT of the upper abdomen and Intravenous CM is administered given that the pa-
the water volume may be reduced to 400 ml. Administra- tient’s renal function is considered. For i.v. contrast en-
tion of an anticholinergic agent (e.g. butylscopolamine 20 hancement of the abdomen, 1.5–2 ml/kg body weight
mg i.v.) to reduce bowel motility is optional. (maximum 180 ml) 300–350 mg/ml non-ionic low- or
For abdominal CT of the small bowel, CT enteroclysis, iso-osmolar contrast material should be used at 3–5 ml/s
the filling of the bowel requires a larger volume, approx- injection rate, using a power injector. The use of a dual
imately 1.5 litres of water. The patient can drink the water syringe injector is recommended by which a 40-ml injec-
during 1 h before the examination or it can be adminis- tion of physiological saline can be administered immedi-
tered through a naso-gastro-jejunal tube. By using a ded- ately after the CM injection. This assures that the whole
icated (150 ml/min rate) power injector, optimal filling of CM volume is utilised for contrast-enhancement purpos-
the whole small bowel may be achieved during enterocly- es and it decreases the otherwise undesirably high CM
sis. CT enteroclysis can also be performed during i.v. con- concentration in the brachiocephalic vein and the supe-
trast enhancement. rior vena cava.
CT of the colon requires i.v. contrast enhancement and CT angiography and examination of the liver and pan-
is performed after cleaning the bowel and insufflating air creas is preferably performed using bolus-tracking tech-
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nique. When this is not available, the approximate ex- For CT of the liver, a so-called three-phasic examina-
amination start for CT angiography is 15–25 s, portal-ve- tion is required. This involves examination before (non-
nous inflow phase (also called the late arterial phase) enhanced, native) and during i.v. contrast enhancement
25–30 s and venous phase (also called portal, or portal- in the portal-venous inflow and in the venous phase. For
venous phase) 70–90 s after CM injection start. CT angi- follow-up of NET liver metastases, some restrict CT ex-
ography may be needed in the preoperative setting, but amination to the venous contrast-enhancement phase
usually the examination in the portal-venous inflow and only when the initial imaging work-up has shown
phase is sufficient to evaluate the anatomy of the arteries better delineation of the liver metastases in the non-en-
and their relation to the tumors. Also, the portal-venous hanced examination and/or in the portal-venous inflow
inflow phase is in most cases sufficient for EPT diagnosis, phase one or both of these phases are added. This routine
and examination in the so-called pancreatic phase (at ap- is, however, insufficient since there is a risk that new well-
proximately 40 s after CM injection start), which is advo- vascularised metastases may escape detection. Also, fatty
cated for CT of ductal pancreatic carcinoma, is generally infiltration of the liver, which may be initiated by medical
not as advantageous for EPT imaging. therapy, can significantly change the imaging prerequi-
For proper examination of the liver, a sufficient amount sites. Liver metastases initially diagnosed during the ve-
of iodine must be injected in order to achieve adequate nous phase may no longer be visible at follow-up, but
enhancement of the normal liver in the venous contrast- show up in the non-enhanced examination and/or the
enhancement phase to optimise delineation of the poorly portal-venous contrast-enhancement phase. The risk of
vascularised metastases. A high CM injection rate, at misinterpreting areas of normal parenchyma in a fatty
least 3–5 ml/s, results in proper enhancement of the aor- infiltrated liver as metastases is also reduced by using
ta and the larger arteries for CT angiography. A similarly three-phasic CT examination. Moreover, characterisa-
high i.v. CM influx is needed for enhancement of well- tion of an adrenal incidentaloma may be performed when
vascularised liver metastases in the portal-venous inflow a pre-contrast examination is also included.
phase and to achieve adequate enhancement of the pan- Coordination of CT scanning in relation to the CM
creas and renal parenchyma. Also, a high CM injection injection is best controlled by using the ‘bolus-tracking’
rate allows a better separation over time between the var- technique, for which computer software is regularly sup-
ious contrast-enhancement phases. plied together with the CT scanner. This allows monitor-
For CT enteroclysis, a naso-jejunal tube is placed ing of the aortic enhancement during contrast medium
downstream to the Treitz ligament, and 2 litres of warmed administration in order to determine the optimum time
tap water are administered preferably by using a pump at point for the examination start. Various routines also ex-
150–200 ml/min. Intravenous glucagon or anticholiner- ist in the use of the bolus-tracking technique. For CT
gic drug is recommended and CT scanning is then per- angiography and examination in the portal-venous
formed during i.v. contrast enhancement 50 s after injec- contrast-enhancement phase a fixed attenuation value
tion of 120–150 ml at 3 ml/s. Because small lesions are (around 150 Hounsfield units, HU) in the abdominal
anticipated, reconstruction of thin, approximately 2 mm, aorta may be used to initiate the scanning start. As an
sections are recommended and viewing using multipla- alternative, a lower value (around 100 HU) may be used
nar reconstructions and cineloop is mandatory. to trigger the examination start but needs to be followed
When the thorax and/or the neck is examined togeth- by a 10–15-s scan delay. In combined CT examinations of
er with the abdomen, the amount of CM and the injection the abdomen and thorax, including three-phasic CT of
rates are adjusted to what is required to perform a proper the liver, the order that scanning of these body regions is
CT of the abdomen. When the thorax and/or the neck, by performed depends on how the bolus-tracking technique
contrast, are examined separately, the amount of CM in- is applied. Initially non-enhanced scanning of the liver is
jected and the injection rate can be decreased. MDCT of generally performed. Then the liver is examined in the
the neck also requires a somewhat lower CM injection portal-venous inflow phase and thereafter the thorax and
rate: approximately 1.5–2 ml/kg body weight of CM is abdomen in the venous phase. Alternatively, an examina-
recommended to be injected at 2.5 ml/s and using a 40-s tion of the thorax early after CM injection start is favored
scanning delay. For CT examination of the thorax, even and coordinated so that the subsequent scanning of the
less CM and a lower injection rate can be used. Approxi- liver is performed in the portal-venous inflow phase, and
mately 1–1.5 ml/kg body weight of CM is administered at thereafter the whole abdomen is examined in the venous
about 1.5 ml/s and a scanning delay of 60 s is preferable. phase.
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 Radiation Dose
The radiation dose administered to the patient varies
with the examination protocol and the type of CT scan-
ner. A high tube voltage and tube current, a long tube ro-
tation time and a low pitch increases the dose. In order to
maintain a proper image quality in large-size patients, the
tube current is increased. This may be decreased in small-
size patients. This results in a higher radiation dose to
large- compared to small-size patients. With a MDCT
scanner with few channels, the relatively narrow package
of detectors needs to be rotated more times in order to
scan the patient than in an MDCT scanner with addition-
al channels and a wider detector package. With each tube
rotation, the so-called penumbra zone of radiation at the
cranial and caudal edges of the detector package adds to
the radiation dose, consequently resulting in a higher dose
to the patient in the former case. Fig. 1. Transaxial CT image of a large gastric carcinoid type III
An examination in a 16-channel MDCT scanner 16 ! extending from the stomach into the surrounding fat. Orally ad-
1 mm (‘one run’) of a patient of 70 kg results in an ap- ministered contrast medium is seen in the antrum of the stomach
proximate radiation dose of 6 mSv for the whole abdomen (arrow).
and 4 mSv for the upper abdomen (liver) from the dia-
phragm to the iliac crest. An optimal MDCT examina-
tion of the abdomen comprising three-phasic CT of the distend the duodenum with water and to perform the ex-
liver and examination of the pelvis in this 70-kg patient amination during i.v. contrast enhancement since this
thus results in a 14-mSv radiation dose. Corresponding will facilitate detection of the usually markedly contrast-
figures for MDCT of the thorax is 3.5 mSv and of the neck enhancing tumor which is depicted against the low at-
4.5 mSv. By comparison, the resulting radiation dose is tenuating water in the bowel lumen.
approximately 1/4 higher when using a 4-channel MDCT Functional EPTs are typically small, sharply delineat-
scanner (4 ! 2.5 mm). ed and can be multiple in patients with the MEN-1 syn-
drome. These tumors tend to be best visualised as evenly
Image Findings contrast-enhancing tumors in the portal-venous inflow
Gastric, duodenal, rectal and colonic NETs are diag- phase (at approximately 30 s) rather than in the pancre-
nosed by endoscopy. The role of CT in these cases is to atic contrast-enhancement phase (at approximately 40 s
detect regional and distant metastases for staging of the after CM injection start). In the venous contrast-en-
disease. hancement phase, EPTs usually exhibit higher attenua-
For type 1 and type 2 gastric carcinoids, CT is not re- tion than the surrounding normal pancreas.
quired except for large (12 cm) and invasive tumors de- Non-functioning EPTs are usually larger and may
tected by EUS. Type 1 tumors are predominantly located have calcifications that are best depicted in the non-con-
in the fundus and body of the stomach and are typically trast-enhanced examination. Larger EPTs are usually not
multicentric, !1 cm in diameter, rounded with sharp as well vascularised and may comprise areas of necrosis;
margin and contrast-enhancing. Type 2 gastric carcinoids contrast enhancement is not as pronounced and usually
are usually multiple and located within the stomach wall shows an irregular pattern. CT also delineates the posi-
which is thickened secondary to gastrin hypersecretion. tion of the tumor in relation to the pancreatic and com-
Type 3 gastric carcinoids are solitary, large lesions, mon bile duct, evaluates possible vascular encasement
with a more irregular and more diffusely delineated mar- and stages the disease with respect to regional lymph
gin that may ulcerate. These tumors can also extend into node involvement and presence of distant metastases,
the fat surrounding the stomach (fig. 1). mainly to the liver. Larger EPTs can be confused with
Duodenal NETs are usually small contrast-enhancing ductal pancreatic cancers. However, with a usually slow-
tumors and in the case of gastrinomas may be multiple. ly growing EPT occluding the pancreatic duct, this is di-
For CT diagnosis of the primary tumor it is important to lated proximal to the occlusion and the surrounding pan-
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 and adjacent organs which instead is most likely better
performed by MRI or US. Colonic NETs are generally di-
agnosed by colonoscopy and fluoroscopy, and CT is
therefore utilised to stage rectal and colonic NETs by de-
tecting regional and distant metastases.
CT cannot differentiate liver metastases due to NETs
from any other malignant tumors. Generally, NET liver
metastases are well vascularised and best depicted during
i.v. contrast enhancement in the portal-venous inflow
phase where they show up as high attenuating lesions in
the non-enhanced normal liver (fig. 3). Poorly vascular-
ised NET liver metastases are, however, also frequent.
These are best depicted in the venous contrast-enhance-
ment phase as low attenuating areas relative to the normal
contrast-enhanced high attenuating liver parenchyma.
Larger metastases are fairly often visible in the pre-con-
Fig. 2. CT enteroclysis of a contrast-enhancing carcinoid tumor trast images in which occasional areas of calcification are
in a small bowel loop (thick arrow). Adjacent to the tumor there
are two small contrast-enhancing mesenteric metastases (thin ar- best seen. Peripheral contrast enhancement and central
rows). necroses in larger NET liver metastases are often seen.
Viewing of the CT examination should always be per-
formed using window settings optimised for image read-
ing of soft tissues, lung and bone, respectively. For liver
creatic parenchyma is severely atrophic and appears like and pancreas it is necessary to adjust the window setting
a thin brim surrounding the dilated duct. and decrease the window width and to increase the win-
The small bowel carcinoids are mostly found in the dow centre (level) in the contrast-enhanced images to op-
ileum rather than in the jejunum and are usually small timise lesion detection.
and occasionally multiple. Consequently, these small The CT appearance of NET lymph node metastases is
tumors are difficult to diagnose as filling defects at CT similar to those from other malignant tumors, although
enteroclysis (fig. 2). With the use of a positive (e.g., di- a marked contrast enhancement is frequent. However,
luted barium sulphate solution) oral CM the usually some particular anatomical sites should be kept in mind
high attenuating carcinoid is more likely to escape de- during image reading. Besides in the mesentery and in
tection than when the lesion is surrounded by a low at- the retroperitoneum, lymph node metastases from mid-
tenuating oral CM such as water, similarly to what was gut carcinoids can often be found ventrally in the lower
previously discussed regarding diagnosis of duodenal thorax adjacent to the thoracic wall and to the heart
tumors. (fig. 4). Also, retrocrural lymph node metastases are not
Frequently, midgut carcinoids present as mesenteric infrequent (fig. 5) as well as subcutaneous and breast me-
metastasis (fig. 2). These can induce an intense desmo- tastases (fig. 6) from midgut carcinoids. When evaluat-
plastic reaction causing contraction and tethering of the ing the CT examination for lymph node metastases, in
adjacent bowel loop resulting in partial or complete in- anatomical regions where these may be surrounded by
testinal obstruction. Vascular encasement of the superior fat, it is often helpful to adjust the window setting by in-
mesenteric artery and vein may compromise bowel cir- creasing the window width to facilitate lesion detection.
culation. At CT, this is reflected as an irregular soft tissue Also, the use of multiplanar reconstructed images is ad-
mass, typically with one or several areas of calcifications, vantageous for depiction of small lymph node metasta-
surrounded by radiating streaks in the mesenteric fat re- ses. Peritoneal carcinosis is occasionally seen, most often
sembling spokes in a wheel. The superior mesenteric ar- in the ventral aspect of the abdomen (fig. 7).
tery and/or vein or branches/tributaries of these vessels Lung metastases from NETs, similarly to those from
may be encased by the tumor. other malignant tumors, appear as rounded, usually mul-
For NETs of the colon and the rectum, the role of CT tiple and generally well-delineated soft tissue opacities.
is not to detect the primary tumor or to appreciate its in- NET bone metastases are often sclerotic (blastic), but can
vasion of the rectal wall, the surrounding mesorectum be osteolytic and sometimes show a mixed appearance.
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Fig. 3. a Transaxial CT image during i.v.
contrast enhancement in the portal-ve-
nous inflow phase of several well-vascu-
larised midgut carcinoid liver metastases.
b In the venous phase the metastases are
no longer discernible.

Fig. 4. Transaxial CT image during i.v. contrast enhancement in Fig. 5. Transaxial CT image during i.v. contrast enhancement in
the venous phase of two retrocrural midgut carcinoid lymph node the venous phase of two metastases in the right thorax in front of
metastases (arrows). and behind the inferior vena cava, respectively (arrows).

Documentation and Reporting of Results meningeal disease are non-measurable lesions. Except for
For research, the RECIST (Response Evaluation Crite- the quantitative description of the measurable lesion siz-
ria in Solid Tumours) criteria are regularly used as the es and the sum of products or lengths, according to the
reference standard by which tumor response to treatment WHO and RECIST criteria, respectively, also a qualita-
is reported and these criteria are therefore advantageous tive description of the tumors regarding treatment re-
when comparing the results of different trials. However, sponse, e.g. necrosis, should be reported. The contrast-
in the daily clinical routine, the WHO (World Health Or- enhancement phase in which the lesions are best depicted
ganisation) criteria are usually applied. Measurable le- should be reported. In order to accurately communicate
sions should exceed 1 cm largest diameter. Necrotic or the diagnostic information, liaison between radiologists
confluent lesions should not be measured. Bone metasta- and clinicians is essential.
ses, pleural fluid, ascites, peritoneal carcinosis and lepto-
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Fig. 6. Transaxial CT image during i.v. contrast enhancement in Fig. 7. Transaxial CT image during i.v. contrast enhancement in
the venous phase of a metastasis in the left breast from a lung car- the venous phase of a patient with midgut carcinoid who has de-
cinoid. veloped peritoneal carcinosis. Tumor lesions are seen ventrally
adjacent to the abdominal wall both on the right and left side (ar-
rows).

Table 2. MRI diagnosis of NETs

Type of NET Sensitivity Specificity Detection rate Number of Reference

mean (range) mean (range) mean (range) patients/studies

Endocrine pancreatic tumor 93% (85–100) 88% (75–100) 54/2 21, 22

73% (50–94) 192/5 6, 9, 11, 23, 24
Liver metastases 82% (80–85) 74/3 11, 15, 23
95% 64/1 25
Extrahepatic abdominal soft tissue metastases 89% 100% 34/1 15
68% (55–81) 58/2 11, 23

Data in the literature on the sensitivity, specificity and detection rate for NET diagnosis by MRI.

Magnetic Resonance Imaging obtained [21, 22]. An even larger number of 192 patients
were included in 5 studies showing a mean 73% (range
Sensitivity, Specificity and Detection Rates 50–94%) detection rate for EPT [6, 9, 11, 23, 24].
The number of studies on MRI in NET patients is even Diagnosis of NET liver metastases was evaluated in 3
smaller compared to CT. The MRI-acquired sensitivity, trials including 74 patients resulting in an overall mean
specificity and detection rate (mean and range based on 82% (range 80–85%) detection rate [11, 15, 23]. In a direct
the number of patients and studies) for NETs at various comparison of MRI with somatostatin receptor scintig-
anatomical sites is presented in table 2. raphy and CT in 64 patients, MRI detected 95% of liver
In 2 studies on MRI for detection of EPT, a fairly large metastases [25].
number of 54 patients were included and a mean 93% Extrahepatic abdominal soft tissue metastases were
(85–100%) sensitivity and 88% (75–100%) specificity was evaluated in 34 patients showing a sensitivity and speci-
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ficity of 89 and 100%, respectively [15]. In 2 studies on 58 Information Provided by the Clinician
patients a mean detection rate of 68% (range 55–81%) was In order to optimise the MRI performance and de-
obtained [11, 23]. crease the risks from the examination procedure, the re-
ferring physician needs to provide information regarding
Hard- and Software Requirements patient’s diagnosis, medical therapy, previous surgery,
The development of MRI over the last few years has kind of surgery and the findings at surgery and results of
resulted in increased field strengths; with current stan- previous imaging examinations. Information regarding
dards an MR scanner with a field strength of 1.5 T or the presence of diabetes, renal impairment (risk of neph-
higher should be used. The use of a phased array torso rogenic systemic fibrosis) and magnetic metal implants
coil is recommended. are mandatory. Please see also pertinent parts in the cor-
The scanner should allow examination with at least responding paragraph regarding CT.
3 mm and not more than 5 mm thick sections. The ability
to use fast acquisitions in 3D during one breath hold is rec- Examination Technique
ommended to decrease or eliminate respiratory image ar- In order to optimise image quality, the field of view
tefacts and facilitate the use of i.v. CM. Fat-suppressed se- should be kept as small as possible and the thinnest sec-
quences are recommended to increase tissue contrast. The tions available should be chosen. No slice gap should be
image quality for various MRI sequences may, however, used if it can be avoided. In contrast to CT, i.v. adminis-
vary between scanners from different vendors and with tration of an anti-peristaltic drug (e.g. butylscopolamine
the field strength. For MRI of the pancreas, MR cholan- 20 mg i.v.) is recommended to optimise MRI examination
giopancreatography (MRCP) should be available to visu- of the pancreas and bowel.
alise the pancreatic duct and detect any duct obstruction. MRI is generally not optimal for thorough examina-
tion of extended body areas. In order to allow for a high-
Patient Information and Preparation quality MRI, including all proper sequences and dynam-
In general, the presence of magnetic metal implants ic imaging during i.v. contrast enhancement, only a lim-
and pacemakers is considered a contraindication for per- ited part of the body can be examined within a reasonable
forming MRI. Patients should be asked about any previ- period of time. In addition to this fact and due to the gen-
ous metal implant procedures so that the material can be erally more limited availability of MRI compared to CT,
checked against a list of procedures, available at MRI de- MRI is best used as a ‘problem-solving tool’. It can be ap-
partments, that precludes an MRI examination. plied when there is strong suspicion for a NET not docu-
The problem with claustrophobia is more pronounced mented by other imaging modalities and when the results
with MRI than CT and the patient should be informed of these are equivocal or contradicting. Conversely, if ex-
that during the examination he or she will be placed in a tended body areas are included, there is usually no time
long tunnel and will have to remain still during the ap- to apply the most optimal technique and the examination
proximately 30 min of the examination. If the patient is needs to be performed with thicker sections, fewer se-
claustrophobic, administration of diazepam may be nec- quences and without applying proper contrast-enhance-
essary. During the examination there will be a loud crack- ment techniques.
ing sound in the scanner that will require earplugs. When The MRI sequences that are generally recommended
CM needs to be administrated, i.v. access is obtained and for the detection of NETs are fat-saturated transaxial T1-
before some examinations, e.g. of the small bowel, the weighted (if available water selected) and fat-saturated
patient needs to be at the department an hour in advance T2-weighted sequences (if available spectral inversion re-
for filling of the bowel. Before MRI of the pancreas, fill- covery SPIR) and optionally fat-saturated transaxial in
ing of the stomach and duodenum with paramagnetic and out of phase T1-weighted sequences. For MRI of the
fluid is advantageous to decrease image artefacts that pancreas, MRCP should also be performed by coronal
may impair the image quality, especially of MRCP. radiated T2-weighted thick slice (25 mm) radiated se-
The patient’s history should be checked for diabetes quences with two ranges including the pancreatobiliary
and renal impairment, and the risk for nephrogenic sys- junction and the pancreatic body, respectively, to better
temic fibrosis, which may be associated with the use of evaluate the regional anatomy and the relation of the EPT
gadolinium (Gd) CM in patients with chronic renal fail- to the pancreatic duct and the main bile duct. T2 thin
ure, should be observed when Gd-contrast enhancement slices MRCP with 3D acquisition is also accurate.
is considered.
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 Short breath-hold sequences are recommended when
‘moving targets’ such as liver, pancreas and bowel are ex-
amined. Transaxial dynamic Gd contrast-enhanced MRI
should be applied. This involves acquisition at 30, 70 and
120 s and at 3–5 min after injection start. 3D acquisitions
are recommended, particularly for dynamic examina-
tions, which can be reconstructed in various anatomical
planes and not only to produce transaxial sections.
The conventional extracellular Gd-based MRI CM,
with a pharmacokinetic pattern similar to that of iodine
CM used for CT, remains the standard for i.v. contrast-
enhanced MRI. Liver-specific i.v. CM for characterisa-
tion of liver lesions are optional.
Some Gd chelates (Gd-DTPA, Gd-EOB-DTPA) imme-
diately after injection act as extracellular contrast agents
but are not eliminated with glomerular filtration. Instead
they accumulate in the hepatocytes during a relatively Fig. 8. Coronal T2-weighted MR image showing a hypersignalling
long period of time following injection (approximately EPT in the pancreatic head (arrowhead). The common bile duct
15–120 min depending on the chelate) and thereby make can be clearly delineated (arrow) and is not compromised by the
tumor.
tumor tissue appear hypointense. Mn-DPDP is a manga-
nese-based hepatocyte-specific contrast agent that re-
tains a strong paramagnetic effect approximately 15 min
to 4 h following injection producing an increased signal equivocal or contradictory at CT and CEUS may better
in the normal liver parenchyma. Mn-DPDP may also be be characterised by using the various MRI sequences and
used for MRI of the pancreas. should also include dynamic examination with i.v. CM.
Superparamagnetic iron oxide particles are composed Although EPT liver metastases commonly show very
of iron oxide crystals coated with dextran or carboxydex- high signal intensities on T2-weighted images, making
tran and are taken up by the Kupffer cells but are not re- their distinction from cavernous haemangioma difficult,
tained in tumor tissue. The particles induce strong relax- Gd-enhanced hepatic arterial dominant-phase imaging
ation effects in the normal liver parenchyma, which be- facilitates their differentiation. Thus, liver metastases
comes hypointense, while tumors appear hyperintense regularly show heterogeneous intense enhancement
relative to the liver parenchyma, thereby increasing tissue while a haemangioma during the arterial dominant con-
contrast. trast-enhancement phase typically displays globular pe-
ripheral skip enhancement. In the haemangioma the con-
Image Findings trast enhancement will subsequently gradually extend
At MRI, a NET appears typically as a low signal lesion towards the lesion center, and during the late contrast-
in T1- and a high signal lesion in T2-weighted images. enhancement phase a complete filling of the haemangio-
The MRI appearances of NETs are similar to those of CT ma is regularly seen. The haemangioma will then appear
concerning tumor delineation, contrast-enhancement hyperintense compared to the normal liver whereas the
characteristics and various morphologic patterns. Al- washout of the CM from a liver metastasis regularly will
though spatial resolution is poorer with MRI than CT, make the lesion appear relatively hypointense [26]. Danet
the better soft tissue contrast of MRI facilitates the detec- et al. [27], who evaluated MR imaging findings on 512
tion of small NETs. metastatic lesions in 165 patients with NETs, reported
Detection of small EPTs is favorable with MRI (fig. 8), that ring enhancement was observed in 72% of patients
particularly with T1 water selected and T2 SPIR thin slic- during the hepatic arterial dominant phase. Peripheral
es. EPT typically is not associated with main pancreatic low intensity area signs were observed in the post-con-
duct stenosis and upstream enlargement (fig. 8), and this trast late phase, and perilesional enhancement in the por-
fact is particularly underlined by the findings at MRCP. tal-venous phase was found in 92% of hypovascular me-
Depiction of small liver metastases is also favorable by tastases.
MRI using these signal sequences and lesions that are
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Fig. 9. Sagittal T1-weighted MR image of the spine showing hy- Fig. 10. Transaxial MR image of the brain during i.v. Gd contrast
pointense midgut carcinoid bone metastases most evident in the enhancement in the venous dominant phase showing contrast-
vertebral bodies of thoracic vertebra 10 and lumbar vertebrae 3 enhancing cerebellar metastases (arrows) from a midgut carci-
and 5. noid.

Table 3. US, EUS, IOUS and CEUS diagnosis of NETs

Type of NET and Sensitivity Specificity Detection rate Number of Reference

US method mean (range) mean (range) mean (range) patients/studies

Endocrine pancreatic tumor

US 39% (17–79) 153/6 28–33
EUS 90% (77–100) 261/10 10, 29–31, 33–38
93% 95% 75/1 39
IOUS 92% (74–96) 127/4 28, 31, 40, 41
Insulinoma
EUS 92% (88–94) 86/4 10, 30, 37, 39
IOUS 92% (84–96) 109/3 28, 40, 41
Duodenal tumors and lymph node metastases
US 18% 25/1 33
EUS 63% 59/2 33, 36
Liver metastases
US 88% 95% 131/1 12
CEUS 82% 48/1 42

Data in the literature on the sensitivity, specificity and detection rate for NET diagnosis by US, EUS, IOUS
and CEUS.
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 The application of MRI for locoregional staging of rec- diagnostic yield of US-guided biopsies in 129 patients was
tal NETs is mentioned earlier in the CT section of this shown to improve by CEUS compared to conventional
paper. Imaging of distant metastases in bone (fig. 9) and US [43]. Liver haemangiomas were easier to characterise
brain (fig. 10) is advantageous by MRI. by CEUS than by pre-contrast US [44].

Documentation and Reporting of Results Hard- and Software Requirements

The documentation and reporting of results of MRI is The possibility of using different transducers with ap-
similar to that of CT. The standardised report used for propriate ultrasound frequencies is important. The deep-
rectal cancer, according to the consensus conferences, er portions of the abdomen require better penetration of
must be used. a low-frequency transducer than more superficial areas
where a high frequency transducer is preferred. With the
recent development of US transducer, the frequency in
Ultrasound one single transducer may be adjusted according to the
different needs during the examination. By harmonic
Sensitivity, Specificity and Detection Rates imaging technique the sensitivity of US can be improved.
US is known to be an operator-sensitive modality lead- The use of i.v. CM for US is an important development of
ing to wide variation regarding sensitivity and specificity the technique, and preferably the US equipment software
of the reported series. The US-, EUS-, IOUS- and CEUS- should allow for CEUS.
acquired sensitivity, specificity and detection rate (mean
and range based on the number of patients and studies) Patient Information and Preparation
for NETs at various anatomical sites is presented in ta- The patient needs to be informed that the examination
ble 3. generally lasts 15–30 min, unless CEUS, which lasts lon-
For EPT diagnosis, a mean 39% (range 17–79%) detec- ger, is performed. During US of the abdomen patients
tion rate was found in 6 studies including 153 patients may repeatedly need to hold their breath for a few sec-
[28–33]. EUS is the most sensitive method for diagnosing onds, and the insertion of an i.v. catheter before CEUS
EPTs and a mean 90% (range 77–100%) detection rate was may cause some discomfort.
shown in 10 studies comprising 261 patients [10, 29–31,
33–38]. In a study on 75 patients the sensitivity was 93% Information Provided by the Clinician
and the specificity 95% [39]. IOUS is also a sensitive meth- US of the abdomen in obese patients is difficult to per-
od for detecting EPTs with a mean 92% (range 74–96%) form and tends to be unreliable as abdominal organs can-
detection rate reported in 4 studies that included 127 pa- not be sufficiently penetrated. These patients are better
tients [28, 31, 40, 41]. When insulinomas are considered candidates for CT or MRI examination. An exception
separately, the mean detection rate of EUS was 92% (range from this rule is US-guided biopsy, which can always be
88–94%) in 4 studies including 86 patients [10, 30, 37, 39] tried and, if needed, converted into a CT-guided proce-
and that of IOUS, 92% (range 84–96%) in 3 studies on 109 dure. The referring physician needs to provide informa-
patients [28, 40, 41]. tion regarding the patient’s diagnosis, kind of medical
For duodenal tumors and lymph node metastases, the therapy, previous surgery, kind of surgery and the find-
detection rate of US was 18% in a study on 25 patients [33] ings at surgery and results of previous imaging examina-
and that of EUS 63% in 2 studies comprising 59 patients tions. If CEUS is contemplated, information should be
[33, 36]. provided regarding previous insertion of cardiac valve
Studies reporting on US for the detection of liver me- prosthesis since the use of i.v. CM for US in these patients
tastases exclusively from NETs are scarce. However, in presently is not accurate (bubbles are broken by such
one study including 131 patients with various NETs, US prosthesis), and recent cardiac angina is a contraindica-
exhibited an 88% sensitivity and 95% specificity, whereas tion due to the risk of acute cardiac insufficiency. Please
in a subgroup of 87 patients with carcinoid tumors the see also pertinent parts in the corresponding paragraph
corresponding figures were 82 and 92%, respectively [12]. regarding CT and MRI.
CEUS has been shown to be more sensitive for the diag-
nosis and characterisation of liver lesions than conven- Examination Technique
tional US. In 48 patients with NETs and suspicion of liv- As opposed to CT, which allows detailed examination
er metastases, the sensitivity of CEUS was 82% [42]. The of the whole abdomen and of additional body regions
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 may be evaluated. CEUS may therefore be considered for
localisation of EPTs and NET liver metastases. By CEUS,
liver metastases in the 2- to 3-mm range may be readily
detected and previously equivocal tumor findings at un-
enhanced US, or CT, may be characterised. CEUS is man-
datory when percutaneous radiofrequency ablation of
liver metastases is considered. A limitation of the tech-
nique, however, is that the whole liver may not be evalu-
ated by US during all phases of contrast enhancement.
In case of negative preoperative US in patients with the
Zollinger-Ellison syndrome, peroperative US is recom-
mended by which the duodenal wall and pancreatic head
can be explored.

Image Findings
Abdominal ultrasound and CT are complementary
radiological methods used to diagnose EPTs, liver metas-
tases, lymph node and mesenteric metastases and these
are an excellent tool for guiding the biopsy needle to ob-
Fig. 11. Transabdominal US image showing a high echogenic liv- tain a tumor tissue specimen (fig. 11). By US, the bile
er metastasis of an EPT. The white track lines for the US-guided
biopsy of the metastasis are displayed in the image.
ducts, the pancreatic duct and vessels may be evaluated
for dilatation and tumor invasion and free fluid in the
abdomen and pleural spaces may be detected.
Intestinal tumors are rarely detected but are occasion-
(thorax, neck) at the same session, US is better suited for ally seen as a low echogenic wall thickening or polypoid
examination of limited parts of the abdomen, for exam- tumor, which is well vascularised. A large locally advanced
ple the pancreas and the liver. intestinal NET infiltrating the surrounding tissues is more
Because US is an operator-dependent procedure, an op- easily detected. The ability of US to differentiate an adeno-
timal examination technique is essential. Examination by carcinoma of the colon from a NET is poor.
using different transducer frequencies is important. Low An EPT is typically a low echogenic and hypervascu-
frequencies (about 3 MHz) better penetrates tissues, but lar lesion. As with CT and MRI, the local extent of the
high frequencies (approx. 5 MHz) allow for higher spatial tumor should be assessed. The relation of the EPT to the
resolution. The advantage and drawback of the high and pancreatic duct and the common bile duct should be de-
low frequencies must be considered during the examina- termined as well as any encasement or invasion of the
tion and used accordingly for examination of deep and splenic vein and the superior mesenteric artery and
superficial parts of the abdominal organs, respectively. vein.
Abdominal organs are generally easier to examine during Mesenteric metastases from a midgut carcinoid and
a breath hold, and it is often advantageous to place the pa- mesenteric and retroperitoneal lymph node metastases
tient in different positions on the examination couch and are seen as low echogenic masses. The desmoplastic reac-
perform US while the patient is standing up or during a tion, which by CT and MRI is a characteristic feature of
Valsalva manoeuvre enlarging the abdominal wall. This a mesenteric metastasis from a midgut carcinoid, cannot
can be especially helpful for the examination of the pan- be detected by US.
creas, when bowel gas, especially in the transverse colon, NET liver metastases cannot be differentiated from
prevents accurate ultrasound penetration. any other type of liver metastases. Small (!1 cm) metas-
Doppler techniques (power Doppler, colour-coded tases generally appear as low echogenic rounded lesions,
Doppler) are valuable in order to evaluate the tumor vas- whereas large (11 cm) metastases usually are highly echo-
cularity and are helpful in distinguishing vascular from genic (fig. 11) with a low echogenic halo and may have
non-vascular tubular structures. central low echogenic necrosis. These lesions often ap-
By dynamic CEUS the temporal and spatial pattern of pear hypervascular by Doppler techniques and CEUS. In
tumor uptake and washout (in- and outflow) of the CM patients with fatty infiltration of the liver, resulting in a
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high echogenic normal parenchyma, the NET metastases Department, Endocrine Unit, University Hospital, Uppsala
may instead appear low echogenic. (Sweden); Massimo Falconi, Medicine and Surgery, University of
Verona, Verona (Italy); Diego Ferone, Departments of Internal
Medicine and Endocrinological and Metabolic Sciences, Univer-
Documentation and Reporting of Results sity of Genoa, Genoa (Italy); David Gross, Department of Endo-
The documentation and reporting of results by US is crinology and Metabolism, Hadassah University Hospital, Jeru-
similar to that of CT and MRI. However, for therapy salem (Israel); Ashley Grossman, St. Bartholomew’s Hospital,
monitoring, the reported lesion sizes by US are generally London (UK); Björn Gustafsson, Medisinsk avd, Gastroseksjon,
St Olavs Hospital, Trondheim (Norway); Rudolf Hyrdel, II. Inter-
difficult to compare with those measured by CT and nal Medical Department, University Hospital Martin, Martin
MRI. This is because the size of the lesions, according to (Slovakia); Diana Ivan, Endocrinology and Diabetology, Klini-
the WHO and RECIST criteria, are measured in the kum der Philipps-Universität, Marburg (Germany); Reza Kian-
transaxial CT and MRI images whereas by US these tu- manesh, UFR Bichat-Beaujon-Louis Mourier, Service de Chirur-
mors are measured in undefined anatomical imaging gie Digestive, Hôpital Louis Mourier, Colombes (France); Günter
Klöppel, Institut für Pathologie, TU München, Munich (Germa-
planes. Usually the US measurement is performed in the ny); Ulrich-Peter Knigge, Department of Surgery, Rigshospitalet,
plane in which the lesions by US appear largest. Also, an Copenhagen (Denmark); Paul Komminoth, Institute for Pathol-
overview of the tumor load is generally difficult to make ogy, Stadtspital Triemli, Zürich (Switzerland); Beata Kos-Kudła,
by US in patients with extended disease. For example, the Slaska Akademia Medyczna Klinika Endokrynologii, Zabrze
assessment of the tumor burden by US in a patient in (Poland); Dik Kwekkeboom, Department of Nuclear Medicine,
Erasmus University Medical Center, Rotterdam (The Nether-
whom the normal liver is almost replaced by metastases lands); Rachida Lebtahi, Nuclear Medicine Department, Bichat
is generally unreliable. Therefore, US is not employed for Hospital, Paris (France); Val Lewington, Royal Marsden, NHS
initial diagnosis or therapy monitoring in clinical trials Foundation Trust, Sutton (UK); Anne Marie McNicol, Division of
(except to evaluate superficial tumor lesions as an adjunct Cancer Sciences and Molecular Pathology, Pathology Depart-
to estimating the lesion size by palpation). However, in ment, Royal Infirmary, Glasgow (UK); Emmanuel Mitry, Hepa-
togastroenterology and Digestive Oncology, Hôpital Ambroise-
the clinical setting, US is an excellent method for diagno- Paré, Boulogne (France); Ola Nilsson, Department of Pathology,
sis and characterisation of NETs. Since CT and US are Sahlgrenska sjukhuset, Gothenburg (Sweden); Kjell Öberg, De-
complementary imaging methods, they may both be ad- partment of Internal Medicine, Endocrine Unit, University Hos-
vantageous for using therapy monitoring in order to de- pital, Uppsala (Sweden); Juan O’Connor, Instituto Alexander
crease the radiation dose to the patient, particularly to Fleming, Buenos Aires (Argentina); Dermot O’Toole, Department
of Gastroenterology and Clinical Medicine, St. James’s Hospital
those who are young and have a long life expectancy. and Trinity College Dublin, Dublin (Ireland); Ulrich-Frank Pape,
Department of Internal Medicine, Division of Hepatology and
Gastroenterology, Campus Virchow-Klinikum, Charité-Univer-
sitätsmedizin Berlin, Berlin (Germany); Mauro Papotti, Depart-
List of Participants ment of Biological and Clinical Sciences, University of Turin/St.
Luigi Hospital, Turin (Italy); Marianne Pavel, Department of
List of Participants of the Consensus Conference on the Hepatology and Gastroenterology, Campus Virchow-Klinikum,
ENETS Guidelines for the Standard of Care for the Charité-Universitätsmedizin Berlin, Berlin (Germany); Aurel
Diagnosis and Treatment of Neuroendocrine Tumors, Perren, Institut für Allgemeine Pathologie und Pathologische
Held in Palma de Mallorca (Spain), November 28 to Anatomie der Technischen Universität München, Klinikum r.d.
December 1, 2007 Isar, Munich (Germany); Marco Platania, Istituto Nazionale dei
Göran Åkerström, Department of Surgery, University Hospi- Tumori di Milano, Milan (Italy); Guido Rindi, Department of Pa-
tal, Uppsala (Sweden); Bruno Annibale, University Sapienza thology and Laboratory Medicine, Università degli Studi, Parma
Roma, Rome (Italy); Rudolf Arnold, Department of Internal (Italy); Philippe Ruszniewski, Service de Gastroentérologie, Hôpi-
Medicine, Philipps University, Munich (Germany); Emilio Bajet- tal Beaujon, Clichy (France); Ramon Salazar, Institut Català
ta, Medical Oncology Unit B, Istituto Nazionale Tumori, Milan d’Oncologia, Barcelona (Spain); Aldo Scarpa, Department of Pa-
(Italy); Jaroslava Barkmanova, Department of Oncology, Univer- thology, University of Verona, Verona (Italy); Klemens Scheid-
sity Hospital, Prague (Czech Republic); Yuan-Jia Chen, Depart- hauer, Klinikum rechts der Isar, TU München, Munich (Germa-
ment of Gastroenterology, Peking Union Medical College Hospi- ny); Jean-Yves Scoazec, Anatomie Pathologique, Hôpital Edouard-
tal, Chinese Academy of Medical Sciences, Beijing (China); Herriot, Lyon (France); Waldemar Szpak, Westville Hospital,
Frederico Costa, Hospital Sirio Libanes, Centro de Oncologia, São Mayville (South Africa); Babs Taal, Netherlands Cancer Centre,
Paulo (Brazil); Anne Couvelard, Service de Gastroentérologie, Amsterdam (The Netherlands); Pavel Vitek, Institute of Radia-
Hôpital Beaujon, Clichy (France); Joseph Davar, Department of tion Oncology, University Hospital, Prague (Czech Republic);
Cardiology, Royal Free Hospital, London (UK); Wouter de Herd- Bertram Wiedenmann, Department of Internal Medicine, Divi-
er, Department of Internal Medicine, Section of Endocrinology, sion of Hepatology and Gastroenterology, Campus Virchow-
Erasmus MC, Rotterdam (The Netherlands); Gianfranco Delle Klinikum, Charité-Universitätsmedizin Berlin, Berlin (Germa-
Fave, Ospedale S. Andrea, Rome (Italy); Barbro Eriksson, Medical ny).
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