Superficial high-dose-rate brachytherapy for primary tumors and relapses after surgery in patients with basal cell carcinoma of the head and neck region: results of a retrospective comparative cohort study

Purpose: The recommended treatments for basal cell carcinoma (BCC) in the head and neck (H&N) region are Mohs surgery, standard surgical excision (SSE), and radiotherapy. According to the literature, local recurrence after surgical treatment in this area is associated with a worse prognosis in case of re-treatment. To our knowledge, there are no reports on high-dose-rate brachytherapy (HDR-BT) for BCC of the H&N region, both in primary lesions and relapses after SSE. This study aimed to fill this gap in the literature.

Material and methods: Inclusion criteria were pathologically confirmed BCC, tumor location in the H&N region, treatment performed with superficial HDR-BT, and a minimum follow-up of 12 months. An analysis was performed on a group of 90 patients, in whom a total of 102 tumors were treated. Subsequently, tumors were divided into two sub-groups, including those treated initially, and treated due to local recurrence after previous SSE. Primary treatment group (PrG) included 59 tumors, whereas 43 tumors were included in recurrent group (ReG).

Results: Statistical analysis did not reveal any significant differences between the groups in terms of age (p = 0.43), treatment duration (p = 0.17), follow-up time (p = 0.96), sex (p = 0.18), local advancement (p = 0.83), and location (p = 0.68). The estimated 5-year relapse-free survival was 96.4% in the PrG and 94.6% in the ReG group, and the difference was not statistically significant (p = 0.72). In the PrG, skin toxicity was as follows: early G1 - 20.3%, G2 - 28.8%, G3 - 42.4%, G4 - 8.5%; late G1 - 33.9%, G2 - 50.8%, G3 - 1.7%, G4 - 11.9%. Whereas, in the ReG, toxicity was as follows: early G1 - 16.3%, G2 - 41.9%, G3 - 37.2%, G4 - 4.6%; late G1 - 30.2%, G2 - 62.8%, G3 - 4.6%. There were no statistically significant differences in the early nor late toxicity between the groups (p = 0.54, p = 0.16).

Conclusions: Superficial HDR-BT is a highly effective treatment for both primary and recurrent BCC of the H&N region, and is associated with acceptable skin toxicity.