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

M Michael Oertel B Bouthaina Dabaja D Dennis Görlich B Bjorn R. Thomas (5St John’s Institute of Dermatology, Guy’s and St Thomas’ National Health Service Trust, London, United Kingdom) V Van Sim (5St John’s Institute of Dermatology, Guy’s and St Thomas’ National Health Service Trust, London, United Kingdom) P Philippa Johnstone (6Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia) A Ayesha Hashmi (8Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, CA) M Mario Levis (9Department of Oncology, University of Turin, Turin, Italy) B Bradley Ackerson (10Department of Radiation Oncology, Duke University Medical Center, Durham, NC) C Christina Hague (11Department of Clinical Oncology, The Christie National Health Service Foundation Trust, Manchester, United Kingdom) C Christopher R. Weil (3Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX) J John Plastaras (13Department of Radiation Oncology, Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, PA) D Daniel Roos (14Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide University School of Medicine, Adelaide, SA, Australia) Y Youlia Kirova (15Department of Radiation Oncology, Institut Curie, Paris, France) R Rainer Fietkau P Penny Q. Fang (3Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX) A Andrea Ng (18Department of Radiation Oncology, Brigham and Women’s Hospital, Boston, MA) F Felix Bock (19Department of Radiotherapy and Radiation Oncology, University Medical Center Rostock, Rostock, Germany) Y Yolanda D. Tseng (20Department of Radiation Oncology, University of Washington, and Division of Radiation Oncology, Fred Hutchinson Cancer Center, Seattle, WA) P Philipp Linde (21Department of Radiation Oncology, Cyberknife and Radiation Therapy, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany) J Jürgen Dunst (22Department of Radiation Oncology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany) S Stephanie Terezakis (23Department of Radiation Oncology, University of Minnesota Medical School, Minneapolis, MN) T Teresa Easwaran (23Department of Radiation Oncology, University of Minnesota Medical School, Minneapolis, MN) J Jan C. Peeken A Andrea Wittig (27Department of Radiotherapy and Radiation Oncology, University Hospital Jena, Friedrich Schiller University Jena, Jena, Germany) H Hong In Yoon (29Department of Radiation Oncology, Yonsei University College of Medicine, Seoul, Korea) R Randa Tao (12Department of Radiation Oncology, University of Utah School of Medicine, Salt Lake City, UT) T Timothy Illidge (30Manchester Academic Health Science Centre, Manchester Cancer Research Centre, University of Manchester, Cancer Research United Kingdom, The Christie National Health Service Foundation Trust, Manchester, United Kingdom) C Chris R. Kelsey (10Department of Radiation Oncology, Duke University Medical Center, Durham, NC) U Umberto Ricardi M Michael S. Binkley B Belinda A. Campbell (6Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia) S Stephen Morris K Khaled Elsayad (1Department of Radiation Oncology, University Hospital Münster, Münster, Germany) M Michael Storck (34Institute of Medical Informatics, University of Münster, Münster, Germany) R Richard T. Hoppe H Hans Theodor Eich (1Department of Radiation Oncology, University Hospital Münster, Münster, Germany)

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.

Article Details

Journal Blood
Volume / Issue Vol. 147, Issue 25
Published June 18, 2026
Pages 3051-3060
ISSN 0006-4971
Publisher Elsevier BV

Journal Info

Blood

Elsevier BV

ISSN: 0006-4971 Health Sciences

Authors (37)

M

Michael Oertel

B

Bouthaina Dabaja

D

Dennis Görlich

B

Bjorn R. Thomas

5St John’s Institute of Dermatology, Guy’s and St Thomas’ National Health Service Trust, London, United Kingdom

V

Van Sim

5St John’s Institute of Dermatology, Guy’s and St Thomas’ National Health Service Trust, London, United Kingdom

P

Philippa Johnstone

6Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia

A

Ayesha Hashmi

8Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, CA

M

Mario Levis

9Department of Oncology, University of Turin, Turin, Italy

B

Bradley Ackerson

10Department of Radiation Oncology, Duke University Medical Center, Durham, NC

C

Christina Hague

11Department of Clinical Oncology, The Christie National Health Service Foundation Trust, Manchester, United Kingdom

C

Christopher R. Weil

3Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX

J

John Plastaras

13Department of Radiation Oncology, Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, PA

D

Daniel Roos

14Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide University School of Medicine, Adelaide, SA, Australia

Y

Youlia Kirova

15Department of Radiation Oncology, Institut Curie, Paris, France

R

Rainer Fietkau

P

Penny Q. Fang

3Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX

A

Andrea Ng

18Department of Radiation Oncology, Brigham and Women’s Hospital, Boston, MA

F

Felix Bock

19Department of Radiotherapy and Radiation Oncology, University Medical Center Rostock, Rostock, Germany

Y

Yolanda D. Tseng

20Department of Radiation Oncology, University of Washington, and Division of Radiation Oncology, Fred Hutchinson Cancer Center, Seattle, WA

P

Philipp Linde

21Department of Radiation Oncology, Cyberknife and Radiation Therapy, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany

J

Jürgen Dunst

22Department of Radiation Oncology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany

S

Stephanie Terezakis

23Department of Radiation Oncology, University of Minnesota Medical School, Minneapolis, MN

T

Teresa Easwaran

23Department of Radiation Oncology, University of Minnesota Medical School, Minneapolis, MN

J

Jan C. Peeken

A

Andrea Wittig

27Department of Radiotherapy and Radiation Oncology, University Hospital Jena, Friedrich Schiller University Jena, Jena, Germany

H

Hong In Yoon

29Department of Radiation Oncology, Yonsei University College of Medicine, Seoul, Korea

R

Randa Tao

12Department of Radiation Oncology, University of Utah School of Medicine, Salt Lake City, UT

T

Timothy Illidge

30Manchester Academic Health Science Centre, Manchester Cancer Research Centre, University of Manchester, Cancer Research United Kingdom, The Christie National Health Service Foundation Trust, Manchester, United Kingdom

C

Chris R. Kelsey

10Department of Radiation Oncology, Duke University Medical Center, Durham, NC

U

Umberto Ricardi

M

Michael S. Binkley

B

Belinda A. Campbell

6Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia

S

Stephen Morris

K

Khaled Elsayad

1Department of Radiation Oncology, University Hospital Münster, Münster, Germany

M

Michael Storck

34Institute of Medical Informatics, University of Münster, Münster, Germany

R

Richard T. Hoppe

H

Hans Theodor Eich

1Department of Radiation Oncology, University Hospital Münster, Münster, Germany