PRONE BREAST RADIOTHERAPY IN EARLY-STAGE BREAST CANCER: A PRELIMINARY ANALYSIS

Abstract Purpose: Women with large breasts have marked dose inhomogeneity and often an inferior cosmetic outcome when treated with breast conservation compared to smaller-sized patients. We designed a prone breast board, which both minimizes breast separation and irradiated lung or heart volume. We report feasibility, cosmesis, and preliminary local control and survival for selected women with Stage 0–II breast cancer. Materials and Methods: Fifty-six patients with clinical Stage 0–II breast cancer were treated with lumpectomy and breast irradiation utilizing a prototype prone breast board. A total of 59 breasts were treated. Indications for treatment in the prone position were large or pendulous breast size ( n = 57), or a history of cardiopulmonary disease ( n = 2). The median bra size was 41D (range, 34D–44EE). Cosmesis was evaluated on a 1–10 (worst-to-best) scale. Results: Acute toxicity included skin erythema (80% of patients experienced Grade I or Grade II erythema), breast edema (72% of patients experienced mild edema), pruritus (20% of patients), and fatigue (20% of patients reported mild fatigue). One patient required a treatment break. The only late toxicity was related to long-term cosmesis. The mean overall cosmesis score for 53 patients was 9.37 (range, 8–10). Actuarial 3- and 5-year local control rates are 98%. Actuarial overall survival at 3 and 5 years are 98% and 94%. Conclusion: Our data indicate that treating selected women with prone breast radiotherapy is feasible and tolerated. The approach results in excellent cosmesis, and short-term outcome is comparable to traditional treatment techniques. This technique offers an innovative alternative to women who might not otherwise be considered candidates for breast conservation.