Optimizing Breast Cancer Radiation therapy With Volumetric Modulated Arc Therapy and Skin Flash: A Case Study Using Deep Inspiration Breath Hold and Cherenkov Imaging

IntroductionRadiation therapy is integral to the management of breast cancer, particularly in cases involving the chest wall and regional lymph nodes.Modern techniques, such as volumetric modulated arc therapy (VMAT), have revolutionized treatment by delivering highly conformal dose distributions while minimizing exposure to critical organs such as the heart and lungs.Studies have shown that VMAT provides superior dose homogeneity and target coverage, especially in complex scenarios requiring chest wall and nodal irradiation.1,2 Deep inspiration breath hold (DIBH) further enhances the safety and precision of VMAT by increasing the distance between the heart and chest wall, significantly reducing cardiac dose.This approach is particularly beneficial for patients with left-sided breast cancer, because it mitigates long-term risks of radiation-induced heart and lung toxicity.3,4 Surface-guided radiation therapy (SGRT) has been shown to accurately reproduce the DIBH position, providing a valuable technique for setup verification.4,5 Despite these advancements, VMAT can underdose the skin and superficial areas of the chest wall without specific modifications.This shortfall poses a risk to treatment efficacy, especially in cases where skin and surface structures are part of the clinical target volume.Although locoregional skin recurrence is rare, recurrence at the skin margin in these patients can be related to the under dosing of the skin and should be monitored and/or augmented when found to be inadequate.6 The "skin flash" technique, which extends the dose distribution beyond the target's surface, addresses this challenge by ensuring better superficial coverage.[7][8][9] Cherenkov imaging has emerged as a valuable tool for real-time dose visualization, enabling clinicians to assess dose coverage directly during treatment.By capturing Cherenkov light emitted during radiation delivery, this technology can identify underdosed areas with precision, facilitating timely adjustments.[10][11][12] This case study demonstrates the integration of VMAT, DIBH, Cherenkov imaging, and adaptive planning to address a dose deficiency observed in the chest wall of a patient with breast cancer.The findings highlight the importance of advanced imaging and adaptive strategies in optimizing radiation therapy outcomes. Methods Patient and treatment detailsA patient with left breast invasive ductal carcinoma involving the chest wall and regional lymph nodes was Sources of support: This work had no specific funding.