Evaluation of adaptive radiotherapy (ART) by use of replanning the tumor bed boost with repeated computed tomography (CT) simulation after whole breast irradiation (WBI) for breast cancer patients having clinically evident seroma.

PURPOSE: The aim of this study is to evaluate adaptive radiotherapy (ART) by use of replanning the tumor bed boost with repeated computed tomography (CT) simulation after whole breast irradiation (WBI) for breast cancer patients having clinically evident seroma.

MATERIALS AND METHODS: Forty-eight patients with clinically evident seroma at the time of planning CT simulation for WBI were included. Two RT treatment plannings were generated for each patient based on the initial CT simulation and tumor bed boost CT simulation to assess seroma and boost target volume (BTV) changes during WBI. Also, dosimetric impact of ART was analyzed by comparative evaluation of critical organ doses in both RT treatment plannings.

RESULTS: Median time interval between the two CT simulations was 35 days. Statistically significant reduction was detected in seroma volume and BTV during the conventionally fractionated WBI course along with statistically significant reduction in critical organ doses with ART (p < 0.0001).

CONCLUSION: Our data suggest significant benefit of ART by use of replanning the tumor bed boost with repeated CT simulation after WBI for patients with clinically evident seroma.