Reduced-Dose Total Skin Electron Beam Radiation Therapy in Mycosis Fungoides and Sézary Syndrome: Systematic Review and Meta-Analysis

PURPOSE: Primary cutaneous T-cell lymphomas are a heterogeneous group of T-cell neoplastic entities associated with significant morbidity and high radiosensitivity. Although research on reduced-dose radiation treatment for mycosis fungoides and Sézary syndrome has significantly increased over the past 2 decades, randomized data are lacking. We aim to summarize the available evidence and analyze the safety and efficacy of reduced-dose total skin electron beam therapy (TSEBT). METHODS AND MATERIALS: A literature search for evidence was conducted, selecting studies with reduced-dose TSEBT in mycosis fungoides and Sézary syndrome that met the inclusion criteria. The studies were critically appraised, and the results were synthesized and interpreted. RESULTS: The analyzed data comprised 11 prospective studies and 11 retrospective studies, with a total of 883 patients. The meta-analysis revealed a pooled overall response rate of 91% (95% CI, 88-93) and complete response rate of 26% (95% CI, 21-31) to reduced-dose TSEBT. The most common toxicities reported were grade 1 and 2 skin reactions. Documented in 7 studies, the time to response ranged from 4 to 8 weeks. Seven studies evaluated the impact of reduced-dose TSEBT on quality of life, and all reported significant improvements in 1 or more subdomains. Fourteen studies indicated that 337 patients (38%) received consolidation/subsequent therapy after TSEBT to maintain remission. Compared with TSEBT monotherapy, the addition of consolidation/subsequent treatments to sustain the response was associated with a progression-free survival or other clinical advantage in 4 of 5 trials. CONCLUSIONS: Reduced-dose TSEBT quickly achieves high overall response rate and improves quality of life with minimal risk of severe adverse events. Knowledge gaps remain on how to optimally prolong these benefits. Investigating maintenance therapy is needed to ensure sustained remission.