Purpose

Facial non-melanoma skin cancers (NMSCs) are primarily managed surgically, but adjuvant or definitive radiotherapy is indicated for high-risk or anatomically complex lesions. While electron-based external beam radiotherapy (EBRT) remains standard, high-dose-rate (HDR) brachytherapy modalities now utilize surface moulds, 3D-printed applicators, interstitial implants, and flap techniques. This systematic review assessed the oncological efficacy, dosimetric characteristics, toxicity, and cosmetic outcomes of these brachytherapy techniques compared with EBRT.

Material and methods

Following PRISMA guidelines, a systematic literature search was conducted across PubMed, Semantic Scholar, Google Scholar, Springer, and Wiley Online Library for studies evaluating modern brachytherapy and EBRT in NMSC. Data on local control (LC), cosmesis, organ preservation, and toxicity were extracted and synthesized.

Results

Twenty-three studies met the inclusion criteria. Modern brachytherapy achieved local control rates of 90% to 100%, demonstrating clinical non-inferiority to EBRT. Brachytherapy exhibited a steeper dose fall-off than EBRT, facilitating target volume dose delivery while sparing adjacent organs at risk. This advantage resulted in high rates of organ preservation, notably avoiding radiation-induced cataracts in periocular applications, and favorable clinician- and patient-reported cosmetic outcomes. Utilizing 3D-printing optimized applicator conformity, and eliminated air gaps in irregular anatomical topographies. Morbidity was primarily limited to transient grade 1 or 2 acute cutaneous reactions, with severe late toxicities below 2%.

Conclusions

Modern HDR brachytherapy provides local control equivalent to EBRT, along with superior dosimetric conformity, functional preservation, and cosmetic outcomes. Its capacity for hypofractionation also offers an operational advantage. Treatment selection requires an individualized, multidisciplinary approach based on tumor depth, anatomical complexity, and institutional capability. Future multicenter randomized controlled trials incorporating standardized patient-reported outcomes are required to validate these findings.