Reirradiation of recurrent skin cancer of the face. A successful salvage modality.

Abstract

The aim of this study was to assess the effectiveness of full doses of reirradiation to salvage previously irradiated recurrent skin cancer of the face. As of December 1990, 17 patients at the Mallinckrodt Institute of Radiology were reirradiated for recurrent skin cancer in previously irradiated areas of the face. There were eight basal cell and nine squamous cell carcinomas. The interval between the two treatments ranged from 6 months to 15 years (median, 4 years). The dosimetry was reviewed, and the radiation doses were recomputed by the biologic effective dose (BED) formula. The accumulated BED from the two irradiation regimens ranged from 48.78 to 143.5 Gy on the skin surface (median, 103 Gy) and 80.93 to 160.68 Gy at 5 mm depth (median, 108 Gy). Local control was achieved in ten patients; two of them had skin defects that required reconstruction. Six of seven patients with persistent tumors had squamous cell carcinoma. Those patients with BED of previous treatment at 5 mm depth less than 55 Gy, and accumulated BED on skin surface of no more than 110 Gy had the best outcome. The residual damage of skin from previous treatment is a function of fraction size and total dose. Reirradiation is a feasible treatment alternative for recurrent skin cancer of the face when cosmesis is a concern.