Interstitial Lung
Diseases/Radiation damage
Dr Nousheen Iqbal
Assistant professor
JMCH , Karachi
What are interstitial lung diseases (ILDs)?
• Interstitial lung diseases (ILDs) Heterogeneous group of lung diseases
• Replacement of normal lung parenchyma with varying degrees of
inflammationand fibrosis(scarring)
• ILDs are notconfined to the true interstitium
• ILDs can involve any part of the lung parenchyma
ILD Etiologies –The Big Three
• Idiopathic
• Idiopathic interstitial pneumonias (IIPs)
• 2. Secondary
• A. Systemic diseases
• CTDs: RA, Systemic sclerosis, PM/DM, MCTD, SLE
• Vasculitides: Eosinophilic granulomatosis with polyangiitis (EGP), Wegener’s granulomatosis
• Sarcoidosis
• Amyloidosis
• Inflammatory bowel disease
• Malignancy (lymphangitic spread of disease)
• B. Exposures
• Radiation, Drugs (antineoplastic agents, antibiotics)
• Inorganic dusts (asbestos, silica, coal, beryllium)
• Organic antigens (hypersensitivity pneumonitis)
Clinical Presentation
Symptoms
• Dyspnea on exertion
• Persistent dry cough
• Less common symptoms: wheezing, hemoptysis, chest pain, constitutional symptoms
• Duration/onset of symptoms highly variable
• Asymptomatic (incidental physical or radiographic findings)
Physical Exam Findings
• Bibasilar inspiratorycrackles
• Clubbing (advanced/fibrotic disease)
• Wheezing (airway disease)
• Signs of pulmonary HTN/corpulmonale(advanced disease)
• Extrapulmonarydisease findings (e.g. rash, joint disease)
ILD –Initial Evaluation
• Past/Associated HistoryConnective tissue disease (known or suspected)
• Malignancy (lymphangiticspread of disease)
• Drug/treatment exposuresChemotherapy, Radiation
• Occupational and environmental exposuresAsbestos, farming, birds,
sand blasting, etc.
• Smoking historyLangerhanscell histiocytosis(LCH), desquamativeinterstitial
pneumonia (DIP), respiratory bronchiolitis-interstitial lung disease (RB-ILD)
• GastroesophagealReflux DiseaseIPF, Systemic sclerosis
Frequency of ILD in Connective Tissue Diseases
• Rheumatologic disease ILD Frequency
• Systemic sclerosis 45%
• Rheumatoid arthritis 20 to 30%
• Polymyositis/dermatomyositis 20 to 50%
• Sjögren'ssyndrome Up to 25%
• Systemic lupus erythematosus 2 to 8%
• Mixed connective tissue disease 20 to 60%
Idiopathic Pulmonary Fibrosis
Idiopathic Pulmonary Fibrosis (IPF)
• Most common idiopathic ILD
• Progressive replacement of normal lung tissue with extracellular matrix
(scarring)
• Histology: usual interstitial pneumonia (UIP)
• Characteristic HRCT findings
• Diagnosis of exclusion!Asbestosis
• Connective tissue disease
• Hypersensitivity pneumonitis
Nonspecific Interstitial
Pneumonia
NSIP
• Age of onset (median):40 to 60
• Association with smoking:Never > former > persistent
• Gender distribution:F > M
• Second most common IIP:14 to 36% of case series
• Differentiation from IPF carries important clinical
implicationsPrognosis
• Choice of therapies
Hypersensitivity Pneumonitis
lung inflammation (pneumonitis) induced by an exaggerated response
to an inhaled foreign substance (hypersensitivity)
Hypersensitivity Pneumonitis–Clinical Presentation
• ACUTE Symptomonset within hours, peaking at 6 –24 hours
• Constitutional symptoms prominent –fevers, chills, myalgias, malaise
• Resolution with cessation of exposure
• SUBACUTE Gradual onset of cough and dyspneaover days–weeks
• Fatigueandweight loss are common
• Waxing/waning symptoms (with intermittent exposure)
• CHRONIC Insidious onset of cough and dyspneaovermonths–years
CTD -ILD
• Lung disease may proceed CTD
• Often patients are younger and female
• Treatment based on underlying CTD –usually with
immunosuppression, such as prednisone
• Ground glass and consolidation more responsive to
immunosupressionthan reticular markings / honeycoming
• Biopsy rarely needed unless unusual features
Current Treatments for ILD
• Pharmacologic Rx:Anti-fibrotics(nintedanib and pirfenidone)
• Immunosupressives(such at prednisone, mycophenolate mofetil)
• Non-pharmacologic Rx:Supplemental O2
• Pulmonary rehabilitation
• •Rx co-morbiditiesGERD
• Pulmonary HTN
Radiation-induced fibrosis:
• Radiation-induced lung injury, including radiation pneumonitis and
radiation fibrosis, is common among patients who have received
radiation therapy, and it is the most common treatment-limiting
toxicity among patients who receive thoracic radiation.
Clinical presentation
• cough
• low-grade fever
• with or without dyspnea
• Radiographic changes that demonstrate a pattern of pneumonitis
with ground glass opacities on HRCT Chest.
• It typically presents one to six months after therapy, while radiation-
associated fibrosis tends to present six to twenty-four months
following radiation therapy.
Treatment
• Approximately 80 percent of patients who develop radiation
pneumonitis respond to steroids, and the response is often dramatic.
• Complete resolution is frequently seen within a week of the initiation
of treatment, with radiographic resolution within two weeks.
• In severe disease and those with long-standing symptoms, the
pneumonitis can be refractory to even high doses of steroids.
• Can progress to respiratory failure and death.
The End
