DIBH (Deep Inspiration Breath-Hold) in left breast radiotherapy -institutional experience
PO-2046
Abstract
DIBH (Deep Inspiration Breath-Hold) in left breast radiotherapy -institutional experience
Authors: Maia Dzhugashvili1, Miguel Montijano1, Beatriz Sevilla2, Carmen Peraza3, Jaume Fernandez4, Daniela Gonsalves2, Marcos Guijarro2, Escarlata Lopez2
1Genesiscare, Radiation oncology, Madrid, Spain; 2Genesiscare, Radiation Oncology, Madrid, Spain; 3Genesiscare, Radiotherapy oncology, Madrid, Spain; 4Genesiscare , Radiation Oncology, Barcelona, Spain
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Purpose or Objective
Radiotherapy is the most effective treatment to eradicate the residual locoregional disease after breast cancer surgery with significative survival improvements after 15 years post diagnostic. For women receiving left-breast radiotherapy (DIBH) is used to further mitigate mortality and morbidity due to late cardiac toxicity, with a demonstrated linear relationship with Mean Heart Dose (MHD). The risk increases 7.4% per Gy, starting within the first 5 years and continuing into the third decade after radiotherapy.
The aim of this study was to evaluate the effect of DIBH irradiation on MHD, V16, V8, V4 and mean, maximum and D10% left anterior descending coronary artery (LADCA) dose.
Material and Methods
75 patients with LBC able to maintain voluntary DIBH ≥ 20 seconds, were irradiated with DIBH, all received a total dose of 40.05Gy/2.67Gy per fraction in breast/chest wall and 58 patients a concomitant boost of 48Gy/3.2Gy per fraction. The target volume was delineated on CT in DIBH.
Tangent-based intensity modulated radiation therapy (n: 71) or VMAT (n:4) plans were developed for both datasets. Patient set-up and tracking in FB/DIBH was monitored by Surface Guided Radiation Therapy (VisionRT, London, UK), after daily validation by cone beam CT matching.
Results
DIBH reduces significantly MHD, V16, V8, V4 and mean, maximum and D10% LAD dose compared to FB (p = 0.001). DIBH average MHD was 1.20 Gy (0.87-1.62) and average LADCA Dmean of 4.95 Gy (2.79-9.14) with respectively in FB 3.18 Gy (2.47-4.26) and 20.20Gy (12.29.-25.40).
Conclusion
DIBH in LBC does lead to a significant reduction in heart and LADCA doses by increasing the distance between target and heart. These reductions could contribute to increase cardiovascular health of LBC.
These findings apply to all patients and further studies will indicate to which subgroups the benefits are more pronounced.