Single-Fraction Adjuvant Electronic Brachytherapy after Resection of Conjunctival Carcinoma

SIMPLE SUMMARY: A centralized distribution of specialized oncologic facilities is a widely repeated situation in many latitudes around the globe, limiting the patient’s access options to specialized treatments. Strategies to alleviate the overpassed attention capacities in low- and middle-income countries, such as Peru, have driven the attention of practitioners towards hypofractionated treatments. In order to shorten treatment times and hospital visits, treating ocular conjunctival carcinoma with a single-fraction electronic brachytherapy approach arises as a novel option, which further increases the current therapeutic arsenal against this entity. We aim to report the clinical findings of this treatment modality, in terms of feasibility, oncological outcomes and toxicity profile, while opening a new possibility of diminishing patient- and health care-related financial impact. ABSTRACT: A retrospective study was performed to assess the outcomes of a single-fraction adjuvant electronic brachytherapy (e-BT) approach for patients with squamous cell conjunctival carcinoma (SCCC). Forty-seven patients with T1–T3 SCCC were included. All patients underwent surgery followed by a single-fraction adjuvant e-BT with a porTable 50-kV device. Depending on margins, e-BT doses ranged between 18 to 22 Gy prescribed at 2 mm depth, resembling equivalent doses in 2 Gy (EQD2) per fraction of 46–66 Gy (α/β ratio of 8–10 Gy and a relative biological effect (RBE) of 1.3). The median age was 69 (29–87) years. Most tumors were T1 (40.4%) or T2 (57.5%) with a median size of 7 mm (1.5–20). Margins were positive in 40.4% of cases. The median time from surgery to e-BT was nine weeks (0–37). After a median follow-up of 24 (17–40) months, recurrence occurred in only two patients (6 and 7 months after e-BT), yielding a median disease-free survival (DFS) of 24 (6–40) months and DFS at two years of 95.7%. Acute grade 2 conjunctivitis occurred in 25.5%. E-BT is a safe and effective for SCCC treatment, with clinical and logistic advantages compared to classical methods. Longer follow-up and prospective assessment are warranted.