Single-Fraction Radiation Therapy for Localized Cutaneous T-Cell Lymphoma

Purpose: Mycosis fungoides is the most common type of cutaneous T-cell lymphoma (CTCL). Single-fraction radiation therapy has been used as a skin-targeted therapy to treat localized CTCL lesions. The objective of this study was to investigate the treatment outcomes associated with single-fraction radiation therapy for CTCL.

Methods and materials: We retrospectively studied the outcomes among patients with CTCL treated with single-fraction radiation therapy at our institution between October 2013 and August 2022. Clinical response (complete response [CR], partial response [PR], or no response [NR]) and retreatment response were evaluated.

Results: A total of 242 lesions from 46 patients were analyzed, for an average of 5.3 lesions treated per patient. The majority of lesions presented with a plaque morphology (n = 145, 60.0%). All lesions were treated to a dose of 8 Gy in 1 fraction. Median follow-up was 24.6 months (range, 1-88 months). Of the 242 lesions, 36 (14.8%) had an initial PR or NR; all were retreated with the same regimen to the same site at a median interval of 8 weeks. Eighteen of the retreated lesions (50.0%) went on to have a CR. Thus, the overall CR rate for CTCL lesions was 92.6%. No recurrences were noted in the treated areas after achieving CR.

Conclusions: Single-fraction radiation therapy to a dose of 8 Gy in 1 fraction to localized areas provided a high rate of complete and durable responses in the affected sites.