Heart substructure exposure during left breast cancer radiotherapy: a dosimetric comparison between hybrid VMAT and 3DCRT in free breathing and deep inspiration breath hold (DIBH)
-
Ingrid Romera-Martínez [1] ; Irene Oliveras Cancio [1] ; María Buxó [2] ; Joan Martínez [2] ; Rafael Fuentes-Raspall [4] ; Arantxa Eraso Urién [4] ; Joan Carles Vilanova [3]
-
[1] Institute Catalá Oncología
Institute Catalá Oncología
Barcelona, España
-
[2] Instituto de Investigación Sanitaria Fundación para la Investigación del Hospital Clínico de Valencia
Instituto de Investigación Sanitaria Fundación para la Investigación del Hospital Clínico de Valencia
Valencia, España
-
[3] Universitat de Girona
Universitat de Girona
Gerona, España
-
[4] Radiation Oncology and Medical Physics of Girona Research Group (ONCORFIM), Girona, España
-
- Localización: Clinical & translational oncology, ISSN 1699-048X, Vol. 27, Nº. 11, 2025, págs. 4177-4184
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
-
Resumen
Background and purpose Radiotherapy plays a pivotal role in breast cancer treatment. Incidental irradiation of the heart can cause cardiac toxicity. We conducted a dosimetric comparison between Hybrid VMAT (H-VMAT) and 3D Conformal Radiotherapy (3DCRT) in both Free Breathing (FB) and Deep inspiration breath hold (DIBH) techniques for left-sided breast cancer patients.
Materials and methods Thirty-seven patients underwent CT scans in both FB and DIBH positions. Heart substructures were delineated following established guidelines. Subsequently, 3DCRT and H-VMAT plans were generated for each patient in both breath techniques. The dosimetric parameters of heart and its cavities were analysed: Dmean(Gy) and V5Gy(%) for heart substructures, Dmean(Gy), V25Gy(%) and V30Gy(cm3 ) for heart and D98%(%), D2%(%), D50%(%) and V95%(%) or V90%(%) for PTVs. Statistical analyses were performed.
Results The analysis revealed statistically significant differences for the heart, and its cavities. The 3DCRT plans generated in DIBH offered a statistically significant lower dose for the heart and its substructures compared to the other techniques.
When comparing PTV dosimetry, the H-VMAT plans showed an increase D98%(%) and a decrease D2%(%) relative to the 3DCRT plans, for both breathing techniques employed.
Conclusion Our study demonstrates significant differences in the dosimetric outcomes for the heart substructures among the four evaluated techniques, with 3DCRT in DIBH yielding the lowest parameters for most substructures. Although H-VMAT provided superior target coverage, it resulted in greater low doses incidental exposure of the heart substructures. Notably, 3DCRT plans in the DIBH setting exhibited lower doses compared to H-VMAT in FB, supporting its preferential use for minimising cardiac exposure.