High-dose-rate brachytherapy of primary cutaneous B-cell lymphoma: the first reported case series

Introduction
Cutaneous B-cell lymphomas (CBCLs) are a rare group of diseases. External beam radiation therapy is recommended to treat CBCLs in all subtypes for locally advanced cases. However, there are no reports on high-dose-rate brachytherapy (HDR-BT) exclusively dedicated to CBCLs. The purpose of this paper was to report the first case series of CBCLs treated with HDR-BT.

Material and methods
Seven patients were treated between 2011 and 2019, with 12 skin lesions histopathologically proven as CBCLs. There were four T1a and eight T2a lesions. HDR-BT was prescribed as the first-line treatment for all cases, as the second-line treatment for recurrences after surgical failure for 4 patients, and as an adjuvant treatment for 1 case. The median total dose was 36 Gy (range, 30-40 Gy) in 10 fractions (range, 6-10 fractions), with a median overall treatment time of 11 days (range, 4-11 days). Treatment toxicity was assessed accordingly to the RTOG scale.

Results
The mean follow-up was 41 months. Local control was 100%. The rates of early toxicity were as follows: erythema (G1) – 33%, patchy epidermal desquamation (G2) – 25%, confluent epidermal desquamation (G3) – 25%, and minor bleeding (G4) – 17%. The reported rates of late toxicity included slight depigmentation (G1) – 59%, small telangiectasia (G2) – 8%, massive telangiectasia (G3) – 25%, and small ulceration (G4) in one site irradiated interstitially (8%).

Conclusions
HDR-BT allows for achieving high local control of CBCLs with relatively low-late toxicity in the form of skin discoloration in most patients.