HDR Mould-Based Brachytherapy for Cutaneous Neoplasms: Toxicity, Long-Term Control, Cosmesis and PROMs

Treating older patients with cutaneous neoplasms (CN) can be challenging as oncological resection and definitive external beam radiotherapy (EBRT) can both have limitations in terms of their therapeutic ratio at critical anatomical sites. Here, we present the cohort study results of high-dose-rate (HDR) mould-based brachytherapy (MbBT) for CN focusing on oncological outcomes and patient-reported outcome measures (PROMs), using custom or three-dimensional-printed moulds.

Between January 2019 and March 2024, 64 patients underwent MbBT. All patients were either deemed unsuitable for radical resection or definitive EBRT or refused them. Patients were prospectively enrolled in a database and underwent clinical evaluation at the end of treatment as well as after 30 and 90 days to assess acute and late toxicity. In addition, oncological follow-up and documentation of their quality of life and subjective cosmetic assessment was performed every 6 months thereafter.

The median age was 80 years. Histology revealed 19 squamous cell carcinomas, 27 basal cell carcinomas, 2 lesions with both histologies, 9 melanocytic tumours and 7 lesions of other histologies. The median treatment dose was 39 Gy (range 30-45 Gy) at 3 Gy per fraction (range 3-4 Gy), administered once daily at 5 days per week. After a median follow-up of 679 days (interquartile range 361-1049 days), there were seven local recurrences (11%). Thirty-seven patients (58%) rated the cosmetic result as at least good, 23 (36%) rated the treatment as more tolerable than expected, while 16 (25%) rated it as at least bothersome. Apart from one grade 4 cataract, no other grade 4 late toxicity was documented.

High-dose-rate MbBT for CN is an effective and well-tolerated treatment option for older and frail patients who are not eligible for radical surgery or definitive EBRT.