Tailored contact brachytherapy for challenging facial basal cell carcinomas: clinical results of 3D printing technology implementation.

BACKGROUND

Basal cell carcinoma (BCC) often arises on cosmetically and functionally sensitive facial sites where standard contact brachytherapy applicators may not conform optimally. Patient-specific, 3D-printed surface applicators may improve geometric conformity, reduce air gaps, and enhance dose reproducibility. We report outcomes of individualized 3D-printed contact high-dose-rate brachytherapy (HDR-BT) for challenging facial BCC.

MATERIALS AND

METHODS

In this single-institution retrospective study, patients with histologically confirmed facial BCC in curved or irregular sites were treated with customized 3D-printed surface applicators. A planning computed tomography (CT) obtained with the applicator in situ guided contouring and optimization. Treatment was delivered with an Ir-192 HDR afterloader to 42-45 Gy in 6-11 fractions. Patients were evaluated at 4 weeks and then every 3-6 months. Primary endpoints were complete response (CR) and local control (LC); toxicity was graded per Radiation Therapy Oncology Group/European Organisation for Research and Treatment of Cancer (RTOG/EORTC) scale.

RESULTS

Twenty-six patients (31 lesions; median age 77 years) were treated: T1 77%, T2 13%, T3 10%. Sites: nose 81%, peri-orbital 13%, ear 6%; 58% primary, 42% postoperative recurrences. At a median follow-up of 32 months, CR and LC were 100%. Acute reactions were mainly grade 1-2 skin changes; higher-grade events were transient. Late toxicity comprised grade 1 discoloration/hypopigmentation in 52% and grade 2 telangiectasia in 23%; 25% had no late toxicity. No grade ≥ 3 late events occurred.

CONCLUSIONS

Individualized 3D-printed contact applicators yielded excellent tumor control with low late toxicity in complex facial BCC. These practice-oriented data support wider implementation of personalized applicators in surface HDR-BT and encourage prospective validation in multicenter settings.