Excellent treatment outcomes from low dose radiation therapy for primary cutaneous CD4+small/medium T-Cell lymphoproliferative disorder

Background and Purpose: Primary cutaneous CD4 + small/medium T-cell lymphoproliferative disorder (PCSMLPD) is a benign behaving condition, typically manifesting as solitary head or neck papules, frequently creating cosmetic concerns. Optimal management of this rare disease is unclear. Herein, patterns of care and treatment outcomes are described, with particular focus on low-dose RT. Materials and Methods: Eligibility required biopsy-proven PCSMLPD on central review, diagnosed between 2007-2022. Patterns of care, treatment responses and relapse patterns were assessed. Freedom-from-progression (FFP) was compared between RT and surgery. Results: 41 patients were eligible. First-line treatments were: RT, 19 (46.3 %); surgery, 17 (41.5 %) (3 received adjuvant RT); watchful waiting, 5 (12.2 %). Median follow-up was 37.7 months. Overall, 24 patients received RT (19 definitive first-line, 3 adjuvant, 2 second-line). 10 (42 %) received 4 Gy in 2 fractions (with no acute toxicities); 14 (58 %) received 20-40 Gy. Complete response rate was 100 %. No post-RT relapses observed. After first-line surgery alone (n = 14, 3 with positive margins), 4 (28.5 %) experienced relapse (2 local, 2 distant). Watchful-waiting (n = 5) led to partial resolution post-biopsy in 4 patients; no complete resolution seen. 3-year FFP for RT alone was 100 % vs 61 % for surgery alone (p = 0.12). Conclusion: RT is a successful, non-invasive option for PCSMLPD: 100 % achieved complete response, with no relapses, and FFP appearing numerically superior to surgery in this cohort. In this first series of lowdose RT for PCSMLPD, 4 Gy in 2 fractions appears an excellent treatment option, offering durable disease control, no acute toxicities and convenient treatment time of only 2 days. Crown Copyright (c) 2022 Published by Elsevier B.V. All rights reserved. Radiotherapy and Oncology 178 (2022) 1-6

Automated summary

This study describes the treatment patterns and outcomes of primary cutaneous CD4 + small/medium T-cell lymphoproliferative disorder (PCSMLPD), with a particular focus on low-dose radiotherapy (RT). The results show that RT is an effective non-invasive treatment option for PCSMLPD, achieving a complete response rate of 100% with no observed relapses. Freedom-from-progression (FFP) appears to be higher for RT compared to surgery. The treatment regimen of low-dose RT with 4 Gy in 2 fractions offers convenient treatment time and no acute toxicities.