High-Dose-Rate (HDR) Plesiotherapy With Flap for the Treatment of Non-Melanoma Skin Cancer

Radiation therapy plays an essential role in the management of nonmelanoma skin cancer. It can be carried out using different modalities: external beam radiation therapy or brachytherapy (BT). High-dose-rate (HDR) BT may be the most efficient modality for selected patients.

Since June 2019, HDR contact BT as an adjuvant or exclusive treatment has been implemented in our department for patients with nonmelanoma skin cancer, using Catheter Surface Flap Applicator Set (Varian). The BT prescription regimens used were 30 Gy in 10 fractions for adjuvant and 40 Gy in 10 fractions for exclusive irradiation, 3 sessions per week. Safety, including acute and late toxicities, and oncologic outcomes, especially local control, were prospectively collected and analyzed, in relation to patients, cancers and treatment characteristics.

From June 2019 to January 2023, 71 patients considered at high risk of local recurrence received flap BT, either exclusively (n =12) or as an adjuvant after surgery (n = 59). The main histologies were squamous cell carcinoma and basal cell carcinoma. With a median follow-up of 28.0 months, 3 local recurrences were observed, all in the adjuvant group. Acute toxicity was mainly cutaneous, with grade 2 radiation dermatitis in 46.5% and grade 3 in 12.7% of patients. Late grade 1 cutaneous toxicity occurred in 52.9% of patients, with no grade ≥2. Three patients experienced late grade 1 nondermatologic toxicity.

HDR flap BT, either as an adjuvant or exclusive treatment, is a safe and effective treatment modality in selected patients with nonmelanoma skin cancers, offering good local control and acceptable toxicity.