Other new radiotherapy techniques

Abstract

Objective To report the NYU research on novel radiation therapy of breast cancer. Radiation therapy has enabled effective breast preservation in the majority of newly diagnosed breast cancer patients. This milestone in the history of breast cancer management is currently revisited to identify the optimal selection of target and fractionation, while assuring minimal radiation exposure of normal tissues adjacent to the breast. Methods Five consecutive prospective trials explored hypofractionated, accelerated regimens of breast radiotherapy that also aim at optimal normal tissue sparing. Results After pilot-testing a 3-week prone regimen of IMRT to the breast with a concomitant boost to the tumor bed, we have prospectively studied in a cohort of 400 women whether a prone versus a supine setup for treatment was superior at sparing lung and heart tissue, while assuring target (index breast) coverage. The results of this trial indicate that the prone setup is superior in >90% of patients. The prone setup also characterizes our two studies of partial breast irradiation delivered over five fractions of 6 Gy each. At NYU this approach is only offered to the subset of patients at the lowest risk of local recurrence after breast-conserving surgery, postmenopausal women with T1 lesions, resected with negative margins. Results at a median follow-up of 5 years demonstrate 2% local recurrence rate. Conclusions Breast radiotherapy after breast-conserving surgery can be safely delivered over 3 weeks. A prone technique enables optimal sparing of the lung and heart in the majority of patients. Current research focuses on a prone setup that includes level III and supraclavicular lymph nodes in patients with positive lymph nodes, to enhance sparing of the lung and heart.