Standard Versus Hypofractionated Low-Dose Total Skin Electron Therapy for Cutaneous T-Cell Lymphoma: A Single-Institution Retrospective Analysis.

Abstract

Low-dose total skin electron therapy (TSET) is an established treatment for diffuse cutaneous T-cell lymphoma. Although traditionally delivered using standard fractionation (STD-fx) schedules, hypofractionated (H-fx) regimens offer a practical, time-efficient alternative; however, comparative data remain limited. This study evaluated clinical responses, toxicity, and hematologic effects of H-fx versus STD-fx low-dose TSET. We retrospectively analyzed 121 courses of low-dose TSET (12 Gy total) delivered to 111 patients with cutaneous T-cell lymphoma from 2015 to 2023. STD-fx was defined as 12 Gy in 6 fractions; H-fx included regimens of 12 Gy in 3 or 4 fractions. Acute toxicities were graded per the Common Terminology Criteria for Adverse Events v5.0 and categorized as "new or worsened" from baseline. Hematologic toxicity was assessed through serial complete blood counts. Overall survival and progression-free survival were measured from TSET completion to event or last follow-up; survival comparisons between regimens were exploratory. Of 121 TSET courses, 104 (86%) were STD-fx and 17 (14%) were H-fx. Median follow-up was 21 months overall and was shorter in H-fx (8 vs 22 months; P < .01). Eastern Cooperative Oncology Group 2 to 4 status was more frequent in H-fx (35% vs 13%; P = .03). Overall response rate (complete response + partial response) was 94% in both groups. At 24 months, overall survival was 87% for STD-fx versus 66.7% for H-fx (P = .13), and progression-free survival was 19% versus 17%, respectively (P = .59). New or worsened acute toxicities were common (98.1% vs 94.1%; P = .37) but mostly low-grade, with no grade 4 events. Rates of dermatitis were similar in STD-fx and H-fx groups (76.9% vs 76.5%), including high-grade events (12.5% vs 23.5%; P = .26). Cytopenias were prevalent at baseline and remained similar posttreatment, with no significant differences between regimens. H-fx low-dose TSET was feasible and demonstrated similar short-term response, acute toxicity, and hematologic effects as STD-fx, although long-term and comparative inferences are limited by the small H-fx cohort and short follow-up duration. In appropriately selected patients, abbreviated TSET regimens may be considered when shorter treatment courses are clinically indicated.