ESTRO 2025 - Abstract Book

S294

Brachytherapy – Head & neck, skin, eye

ESTRO 2025

1508

Digital Poster HDR brachytherapy of the eyelid: a tool for the future Mar Vercher 1 , Sandra Canos 1 , Beatriz Ros 1 , Daniela Cediel 1 , Marina Coll 1 , Mireia Pallares 2 , Alberto Angulo 2 , Carmen Guardino 2 , Miguel A Santos 1 , Victor Gonzalez-Perez 2 , Jose L Guinot 1 , Leoncio Arribas 1 1 Radiation Oncology, Foundation Instituto Valenciano de Oncologia (IVO), Valencia, Spain. 2 Radiation Physics, Foundation Instituto Valenciano de Oncologia (IVO), Valencia, Spain Purpose/Objective: Eyelid malignancies represent less than 3% of all skin cancers in the head and neck. Mohs surgery or wide excision are the primary treatments, achieving local control rates of 95-98%. However, these options are not free from adverse effects, particularly on cosmetics and vision. To explore new treatment options, high dose rate (HDR) brachytherapy has emerged as a potential alternative. Few studies exist, and it is still unclear which treatment offers better local control with minimal cosmetic and functional alterations. Material/Methods: Six patients were treated between June 2019 to July 2023 with HDR brachytherapy, aiming for radical intention. Five tumors were located in the inferior eyelid, and one in the internal border of the eye. One patient had undergone prior surgery before receiving brachytherapy TUBE PLACEMENT 1. Local anesthesia is applied. 2. Insert a folded abocath with the guide into the lower eyelid. 3. Remove the abocath, leaving the guide in place. 4. Attach a small piece of dropper tube to the bottom of the plastic tube and insert both tubes. 5. Position the buttons on the opposite side PLANNING CT: a planning CT is required to delineate the tumor area using opaque material. The slice separation should be 1.5 mm due to horizontal placement of the tubes. PRESCRIPTION: The dose at point A (the midpoint of both plastic tubes) corresponds to 100% of the dose. The prescription is set at 85% of the isodose curve. DOSE & FRACTIONATION: treatment consists of 9-10 fractions of 3.5-4 Gy, twice a day during hospitalization. The most common scheme is 4 Gy in 9-10 fractions depending on tumor size. Lead shielding is used during treatment to protect the eyeball and lens. Results: Follow up was conducted one month after treatment, then every 6 months for two years, and annually for up to five years. None of the patients reported significant side effects, except for eyelash loss. Some experienced mild eye dryness, but it did not affect daily life. No cataracts or other major vision changes were reported, and no cosmetic issues were noted. There were no relapses during the five-year period. Conclusion: HDR brachytherapy for eyelid malignancies is a well-tolerated alternative to surgery, offering good cosmetic results and minimal functional alteration. Although experience is limited due to the low incidence of eyelid malignancies, our results show no relapses and only mild side effects, without interference in daily life.

Keywords: eyelid, high-dose-rate