The role of surveillance imaging for resected high‐risk melanoma

Background Recommendations for surveillance imaging for resected melanoma vary considerably. This study examined the utility of imaging in patients with a high‐risk primary melanoma undergoing a protocolized imaging schedule. Methods This retrospective study involved data collection regarding imaging, recurrence, and outcome characteristics for patients referred to the Victorian Melanoma Service from January 2016–April 2020 and managed for resected stage IIC or III melanoma. Patients with a T4b tumor who did not undergo a sentinel lymph node biopsy were included (T4bNX). Recurrences were “clinically detected” if they were primarily detected by patient symptoms or physical examination, or ‘imaging‐detected’ if the patient was asymptomatic. Cox regression models including time‐varying co‐variates were used to assess the impact of imaging‐detected versus clinically‐detected recurrence on overall survival. Results Over a median follow‐up time of 2.7 years, 199 patients underwent surveillance imaging (T4bNX:22, IIC:33, IIIA:22, IIIB:60, IIIC:61, IIID:1), and 44% (n = 88) experienced disease recurrence. Imaging detected over half (53%) of all recurrences. In adjusted analyses, mortality risk was reduced after an imaging‐detected compared to clinically‐detected recurrence at any given time from the start of surveillance (hazard ratio 0.25, 95% confidence interval 0.10–0.66, p = .005). Conclusion Our study indicates that routine imaging in the early follow‐up period of resected T4bNX, stage IIC and III melanoma plays an important role in the detection of asymptomatic recurrences. Imaging‐detected recurrence may be associated with a survival benefit and studies with more prolonged follow‐up are required to confirm these findings. In this retrospective study including 199 patients with high‐risk resected melanoma who underwent surveillance imaging, 88 individuals experienced disease recurrence. Imaging‐detected recurrence was associated with a reduced mortality risk compared to clinically detected recurrence at any given time from the start of surveillance in an adjusted Cox‐regression model.