Retrospective Analysis of Acute Toxicity Following Breast Cancer Re-Irradiation.

PURPOSE: To evaluate the acute skin toxicity and treatment-related factors in patients undergoing breast re-irradiation in a tertiary cancer centre.

METHODS

A retrospective review was conducted of patients who received a repeat course of breast or chest wall radiation for ipsilateral breast cancer recurrence between April 20, 2011, and December 31, 2023. Patient characteristics, treatment parameters, and clinician-graded acute toxicity were recorded. Associations between toxicity and treatment factors were analyzed.

RESULTS

Seventy patients met inclusion criteria. Acute skin toxicity was lower during retreatment than initial treatment with 22.9% of patients (n = 16) developing moderate/severe reactions during re-irradiation compared with 51.4% (n = 36) during the initial course. Severe toxicity at retreatment was not common, including moist desquamation in 10 patients (14.3%). Toxicity during the initial course did not predict toxicity during re-irradiation (P = .75). Across all fractionation schedules, no significant associations were observed between dose regimen and symptoms such as pruritus, pain, erythema, discoloration, edema, burning, dry desquamation or moist desquamation.

CONCLUSIONS

Breast re-irradiation was well tolerated in the acute setting, with toxicity patterns influenced primarily by radiation dose and delivery. The findings emphasize the need for ongoing prospective work to assess long-term outcomes.