Purpose

Early-stage non-melanoma skin cancer (NMSC) is usually treated with surgical excision with or without adjuvant radiotherapy. Tumor location on facial sub-sites may lead to poor cosmetic outcomes with surgery. Surface mould brachytherapy offers better conformality, reduced treatment duration, and comparable local control and cosmetic outcomes.

Material and methods

Twenty-eight patients with NMSC of the face or scalp received definitive or adjuvant radiotherapy using a customized surface mould brachytherapy technique. Prescription dose was 3,500-4,200 cGy in 9-12 fractions. Clinical target volume (CTV) V100, V150, 0.1 cc, 1 cc, and 2 cc skin doses, and mould parameters were recorded from planning system. Toxicity and cosmetic outcomes were compared with dosimetry and mould parameters using independent sample t-test. Binary mould parameters were compared with toxicity profile using chi-square or Fisher’s exact tests.

Results

Thirteen (46.4%), six (21.4%), and eight (28.6%) patients experienced grade 2 acute skin, late skin, and late subcutaneous toxicity, respectively. Among grade 3 toxicity, only 1 acute skin toxicity was observed. All patients had either excellent or good cosmetic outcomes, while 0.1 cc, 1 cc, 2 cc skin dose, and homogeneity index were significant predictors of late skin, subcutaneous toxicity, and cosmetic outcome. For cosmesis, the distance from catheter midpoint to skin surface was also a significant predictor of outcome. After a median follow-up of 54 months, no disease recurrence was observed in the study cohort.

Conclusions

Surface mould brachytherapy can provide excellent local control and cosmetic outcome for the treatment of NMSC.