High-dose planned adaptive helical tomotherapy for cutaneous angiosarcoma of the scalp.

Abstract

The purpose of this study was to investigate the feasibility and effectiveness of high-dose planned adaptive intensity-modulated radiation therapy (IMRT) with helical tomotherapy (HT) for cutaneous angiosarcoma (cAS) of the scalp. This retrospective cross-sectional included atotal of 12consecutive patients with cAS of the scalp who underwent high-dose planned adaptive IMRT with HT. Prescribed doses were 72.5-74 Gy in 35-37 fractions for the gross tumor volume plus a1-2 mm margin (PTV1), 58-60 Gy in 29-30 fractions for the clinical target volume plus a2-3 mm margin (PTV2), and 46 Gy in 23fractions for the clinical target volume plus a5-15 mm margin (PTV3) over periods of 7.5, 6and 4.5weeks, respectively. The estimated 1‑year and 2‑year overall survival rate were 65.6% and 27.3%, respectively, and the local progression-free survival at 2years was 74.1%. All local recurrences were either in or marginal to the PTV2 or PTV3. No local recurrence was observed in the PTV1. All patients tolerated the treatment without grade3 or higher adverse events during the radiotherapy period. No late adverse events were observed during the follow-up period. Planned adaptive high-dose IMRT with HT has the potential to improve local control rate without increasing adverse events.