Brachytherapy for eyelid cancers: Re-defining outcomes and esthetics in rare histologies.

Purpose: To evaluate local control, cosmetic outcomes, toxicities, and survival outcomes of interstitial high-dose-rate (HDR) brachytherapy treatment in non-basal cell carcinoma malignancies of the eyelid.

Material and methods: This retrospective study analyzed patients with histopathologically confirmed eyelid malignancies treated with adjuvant HDR interstitial brachytherapy (¹⁹²Ir) between August 2007 and August 2024. Outcomes assessed included loco-regional control (LRC), disease-free survival (DFS), overall survival (OS), and toxicities graded by the Radiation Therapy Oncology Group (RTOG). Kaplan-Meier analysis estimated survival rates, while cosmetic outcomes were evaluated using cosmetic assessment of intraocular brachytherapy (CAIB) scale.

Results: Eighteen patients with sebaceous (72.2%) and squamous (22.2%) histologies received 21-49 Gy in 7-14 frac-tions (3-3.5 Gy/fraction). With a median follow-up of 21.93 (IQR, 10.6-152.83) months, no loco-regional recurrences were observed among 13 patients with documented follow-up (LRC, 100%). Two patients died (one from systemic progression without local failure and the other from COVID-19), and three were lost to follow-up. The 5-year OS and DFS rates were 83.3%. Cosmetic outcomes were rated excellent in 55.55% and very good in 44.44% of patients. No grade 3 and above acute toxicities occurred, and eyelid/eye function was preserved in 88.88% (16/18), ensuring organ preservation without late toxicity.

Conclusions: Adjuvant HDR brachytherapy is a safe and effective treatment for eyelid malignancies, achieving excellent local control, superior cosmetic outcomes, and acceptable toxicity. This modality optimizes tumor control, while preserving function and esthetics in this anatomically sensitive region.