Clinical Advantage of Chest-wall Post-mastectomy Radiation Therapy Without Bolus.

BACKGROUND/AIM: The clinical outcomes of post-mastectomy radiation therapy (PMRT) without bolus remain to be fully examined, so that we evaluated clinical outcomes of PMRT without bolus and to measure the chest-wall dose surface histogram (DSH) parameters.

PATIENTS AND METHODS: Fifty-two patients with breast cancer who received PMRT without bolus were retrospectively analyzed. DSH values of the percentage of maximum dose (Dmax ) were measured.

RESULTS: All patients completed the treatment; the median follow-up period was 22.1 months. The 2-year overall survival and local control rates were 85% and 95%. Five patients developed grade 2 acute radiation dermatitis, and none developed grade 2 or higher late radiation dermatitis. The median Dmax in patients who developed grade 0-1 and grade 2 acute radiation dermatitis was 5,178 and 5,365 cGy (p=0.03).

CONCLUSION: PMRT without bolus resulted in a low frequency of grade 2 or higher radiation dermatitis without increasing locoregional recurrences, and the Dmax was the contributing factor for developing acute radiation dermatitis.