Quantifying radiation in the axillary bed at the site of lymphedema surgical prevention.

PURPOSE: Immediate lymphatic reconstruction (ILR) is a procedure known to reduce the risk of lymphedema in patients undergoing axillary lymph node dissection (ALND). However, patients who receive adjuvant radiotherapy are at increased risk of lymphedema. The aim of this study was to quantify the extent of radiation at the site of surgical prevention. METHODS: We recently began deploying clips at the site of ILR to identify the site during radiation planning. A retrospective review was performed to identify breast cancer patients who underwent ILR with clip deployment and adjuvant radiation therapy from October 2020 to April 2022. Patients were excluded if they had not completed radiotherapy. The exposure and dose of radiation received by the site was determined and recorded. RESULTS: In a cohort of 11 patients, the site fell within the radiation field in 7 patients (64%) and received a median dose of 4280 cGy. Among these 7 patients, 3 had sites located within tissue considered at risk of oncologic recurrence and the remaining 4 sites received radiation from a tangential field treating the breast or chest wall. The median dose to the ILR site for the 4 patients whose sites were outside the radiation fields was 233 cGy. CONCLUSION: Our findings suggest that even when the site of surgical prevention was not within the targeted radiation field during treatment planning, it remains susceptible to radiation. Strategies for limiting radiation at this site are needed.