Tailoring Radiation Therapy for Patients With Limited Cutaneous T Cell Lymphoma: Preliminary Clinical Experience With Subtotal Skin Electron Therapy

Background/Aim: Total skin electron beam therapy (TSEBT) is an effective treatment for managing cutaneous Tcell lymphoma (CTCL), but may result in unnecessary toxicity. With the production of a custom rolling shield holding a configurable stack of plastic slats to block uninvolved skin, we implemented a program for subtotal skin electron beam therapy (STSEBT). We report our preliminary experience with STSEBT vs. TSEBT to manage CTCL. Patients and Methods: A retrospective review of 32 CTCL patients who were treated at a single institution between February 28th, 2017, and May 25th, 2022, was completed. Of these cases, seven patients received STSEBT and 25 received TSEBT. Results: Thirty-two patients underwent a course of STSEBT or TSEBT. The median follow-up was 465 days and the median age at diagnosis was 70.8 years. Stage distribution was as follows: one (3%) IA, 16 (50%) IB, 6 (19%) IIB, two (6%) IIIA, five (16%) IVA, and two (6%) IVB. The overall response rate was 96%. For patients receiving TSEBT (n=25), three (12%), 10 (40%), and 11 (44%) had a CR, NCR, and PR, respectively. For the patients receiving STSEBT, four (57.1%), three (42.9%), and zero (0%) had a CR, NCR, and PR, respectively. There was one patient (4%) with no response. Cumulative incidence of progressive skin disease requiring additional electron therapy at three months was 21.1% [IQR=8.6, 51.5%], 36.8% [IQR=20, 68%] at six months, and 57.9% [IQR=38.5, 87.1%] at one year. Low rates of toxicities were recorded. Conclusion: This analysis demonstrated that treatment of CTCL patients with low disease burden with STSEBT results in similar overall response and time to progression compared to treatment with TSEBT.