Radiotherapy for indolent primary cutaneous B-cell lymphoma: an international multicenter ILROG analysis

Oertel M, Dabaja B, Görlich D, Thomas BR, Sim V, Johnstone P, Hashmi A, Levis M, Ackerson B, Hague C, Weil CR, Plastaras J, Roos D, Kirova Y, Fietkau R, Fang PQ, Ng A, Bock F, Tseng YD, Linde P, Dunst J, Terezakis S, Easwaran T, Peeken JC, Wittig A, Yoon HI, Tao R, Illidge T, Kelsey CR, Ricardi U, Binkley MS, Campbell BA, Morris S, Elsayad K, Storck M, Hoppe RT, Eich HT (2026)

Publication Type: Journal article

Publication year: 2026

Journal

DOI: 10.1182/blood.2025032050

Abstract

Abstract: Radiotherapy is an established treatment for low-grade primary cutaneous B-cell lymphoma. Recommendations on its use differ internationally, which prompted our group to conduct this analysis. Twenty-two institutions participated in this international study. Patient eligibility required a diagnosis of limited (T1/T2) primary cutaneous marginal zone or follicle center lymphoma treated with radiotherapy between 1995 and 2023. Data were collected retrospectively until February 2024 within the framework of the International Lymphoma Radiation Oncology Group. Overall, 535 patients were analyzed. Predominant locations were the head (40%) and trunk (36%). Radiotherapy had a median dose of 24 Gy in fractions of 2 Gy. Complete responses were observed in 91% at a median time of 3.6 months following radiotherapy. There was no statistically significant difference between treatments ≤4 Gy and >4 Gy for complete or overall response rates (P = .077 and P = .056, respectively). However, there was an inferior duration of local control with ≤4 Gy (5-year local control 73% ± 12% vs 96% ± 2%; P < .001). Radiation dose was the main prognostic factor in the univariate and multivariable Cox analysis; however, higher doses did not translate into an overall survival benefit. Toxicities rarely exceeded grade 2 but were more frequent in the >4 Gy group. Radiotherapy remains an effective treatment option for indolent skin lymphoma with low toxicity. High response rates are observed with low doses of ≤4 Gy. In comparison to conventional doses, these treatments have a shorter duration of local control but a favorable toxicity profile.

Authors with CRIS profile

Involved external institutions

Universitätsklinikum Münster Germany (DE) University of Texas MD Anderson Cancer Center United States (USA) (US) Guy's and St Thomas' (NHS Foundation Trust) United Kingdom (GB) Peter MacCallum Cancer Centre Australia (AU) Stanford University United States (USA) (US) University of Turin / Università degli Studi di Torino (UNITO) Italy (IT) Duke University Medical Center United States (USA) (US) Christie NHS Foundation Trust United Kingdom (GB) Penn Medicine United States (USA) (US) University of Adelaide Australia (AU) Institut Curie France (FR) Brigham and Women's Hospital (BWH) United States (USA) (US) Universitätsmedizin Rostock Germany (DE) University of Washington United States (USA) (US) Universitätsklinikum Schleswig-Holstein (UKSH) Germany (DE) University of Minnesota (UMN) United States (USA) (US) Technische Universität München (TUM) Germany (DE) Yonsei University Health System (YUHS) Korea, Republic of (KR) University of Utah United States (USA) (US) University of Manchester United Kingdom (GB) Westfälische Wilhelms-Universität (WWU) Münster Germany (DE) Universitätsklinikum Jena Germany (DE)

How to cite

APA:

Oertel, M., Dabaja, B., Görlich, D., Thomas, B.R., Sim, V., Johnstone, P.,... Eich, H.T. (2026). Radiotherapy for indolent primary cutaneous B-cell lymphoma: an international multicenter ILROG analysis. Blood. https://doi.org/10.1182/blood.2025032050

MLA:

Oertel, Michael, et al. "Radiotherapy for indolent primary cutaneous B-cell lymphoma: an international multicenter ILROG analysis." Blood (2026).

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