Single-Fraction Adjuvant Electronic Brachytherapy after Resection of Conjunctival Carcinoma.

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/ß 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.

Single-fraction low-energy electronic brachytherapy for conjunctival lymphoma.

PURPOSE: Conjunctival lymphoma represents an uncommon tumor, accounting for 5-10% of total extranodal lymphomas. Although radiotherapy is a frequent treatment option, limited capacities and lack of specialized centers are common problems in Peru, forcing radiation oncologists to apply short courses of radiotherapy. Here, we report a case series of patients treated with a novel single-shot scheme. Additionally, we present a literature review of the current short-course irradiation strategies. CASES PRESENTATION: Three cases of conjunctival marginal zone (B-cell) lymphoma (marginal zone lymphoma [MZL]/mucosa-associated lymphoid tissue [MALT]) of the fornix are presented. Following biopsy and sonographic assessment of the lesion thickness, we applied a focused single dose of 14 Gy kilovoltage brachytherapy (prescribed to the maximum thickness of the lesion). Follow-up was scheduled in quarterly intervals. After 28, 31, and 40 months of follow-up, none of the three patients treated exhibited acute or chronic toxicities and remained local or distant disease-free. CONCLUSIONS: Single dose kilovoltage brachytherapy was effective and safe in this small cohort of patients. Based on the literature, there is an evidence that local treatment in short-course radiotherapy is effective and should be considered amongst therapeutic options for these patients; however, this novel approach should be evaluated prospectively in a larger cohort.

Phase I/II study on kilovoltage surface brachytherapy in conjunctival cancer: preliminary results.

INTRODUCTION: In ocular conjunctival carcinoma after surgery, adjuvant treatment has a role and kilovoltage surface brachytherapy opens a new door for the range of therapeutic options. MATERIALS AND METHODS: Between October 2014 and June 2017, at the National Institute of Neoplastic Diseases (INEN) from Peru, 39 patients with squamous cell carcinoma of ocular conjunctiva, T1-T3, resected, were selected to receive adjuvant treatment. The portable accelerator of 50-kV INTRABEAM (Carl Zeiss Meditec) was used, after local anaesthesia and blocking of ocular muscles movement. The doses used were 18 Gy for patients with free margins and 22 Gy for positive edges, according to calculation of equivalent dose of 2Gy per fraction of 46 and 66 Gy, respectively, assuming a tumoural α/ß ratio of 8 Gy. The prescription was done to 2 mm depth. RESULTS: The median age was 69 years, distributed evenly between both genders, with a median follow-up of 12 months. The surgical margins were 59% free and 41% committed, with no difference between the institutions where the surgery was performed (P = 0.069). The median tumour size was 7 mm with 2 mm of invasion, 61.5% was T2 and 35.9% T1. The mean time between surgery and irradiation was 1.5 months, 23.1% of patients developed grade I toxicity of spontaneous resolution, without evidence of greater degree in any case. The dose had no statistical relationship with toxicity (P = 0.533). One-year disease-free survival was 96.7%. CONCLUSIONS: Kilovoltage surface brachytherapy is an applicable and reproducible tool in the treatment of squamous cell carcinoma of ocular conjunctiva. The administered doses are well tolerated by patients with low levels of acute toxicity. Longer follow-up is needed to establish disease control rates and late toxicities.