Initial experience with perioperative immune checkpoint inhibitors combined with radiotherapy for head and neck mucosal melanoma: a case series

Background The benefits of perioperative immune checkpoint inhibitor (ICI) therapy for head and neck mucosal melanoma (HNMM) remain unclear. In this study, we aimed to report our initial experience with perioperative ICI combined with radiotherapy (ICI-RT) for patients with HNMM and assess its potential benefits. Patients and methods We retrospectively evaluated the clinical outcomes and adverse events in patients with resectable HNMM who received perioperative ICI-RT between 2018 and 2023 at our institution. The clinical and pathological responses of preoperative ICI-RT were assessed. Results Eight patients were included in this study. The primary tumor site was the nasal cavity in six patients (75.0%) and the paranasal sinus in two (25.0%). The prescribed radiotherapy dose was 48 Gy in 12 fractions or 54 Gy in 18 fractions. All patients received nivolumab as the ICI. The median follow-up time was 20.4 months, and no patient experienced grade ≥3 adverse events. Among those who received preoperative ICI-RT, two patients (50.0%) achieved pathological complete response, and two (50.0%) achieved pathological partial response; one (25%) experienced local recurrence. In contrast, 75% of patients who received ICI-RT following surgery experienced local recurrence. Conclusions Perioperative ICI-RT for HNMM was safely carried out, and ICI-RT therapy before surgery achieved good local control.