Brachytherapy With Radiotherapy and Immunotherapy: Guided HDR Trial in Esophageal Squamous Cell Carcinoma

After the first cycle of nivolumab administered in the screening phase (1st cycle), nivolumab in the study phase was administered intravenously over 30 minutes at a dose of 240 mg every 2 weeks for at least 2 doses, with 1 cycle after to first brachytherapy (2nd cycle), and 1 more cycle after to second brachytherapy (3rd cycle) if feasible. (each cycle was 2 weeks), until disease progression assessed by the investigator per RECIST version 1.1, or unacceptable toxicity.

Brachytherapy protocol starts within 3 weeks after first cycle of nivolumab was administered. After brachytherapy applicator placement, CT simulation scan(s) with dummy source in place will be done for further planning procedure, including adjustment of the applicator and 3D treatment planning. High-dose-rate (HDR) 5-Gy per fraction is delivered to the gross tumor volume (GTV) of esophageal tumor(s), second treatment if applicable will be finished within 2 weeks after the first fraction, a total of 5-12 Gy in 1-2 fractions will be delivered. GTV coverage D90 should equal 100% of prescription. Efforts should be made to spare the adjacent normal organ and to avoid hot spot on normal esophageal mucosa. It is NOT allowed to give concurrent chemotherapy on the days of HDR brachytherapy.