Using long-term CT and PET/CT scans to identify metastatic recurrence in patients with resected melanoma.

This study evaluated how effective regular scanning is in identifying metastatic recurrence in patients with stage III melanoma that was surgically removed. Results showed that scanning every 6 or 12 months was reasonably good at detecting metastatic recurrence.

Melanoma is a form of aggressive skin cancer. Treatment includes surgery to remove the tumor. Stage III melanoma has a high risk of spread to distant parts of the body (metastasis) even after it is removed. It commonly spreads to the brain. Early detection of metastases is important for effective treatment.

Metastasis can be detected by computed tomography (CT) scanning or positron emission tomography (PET)/CT scanning. CT and PET/CT come with the risk of side effects caused by exposure to radiation during scanning. It is important that any risk caused by radiation is outweighed by the benefit follow-up scanning gives patients. It is not known how often patients should have a CT or PET/CT scan or how long follow-up should be in patients with stage III resected melanoma.

The study included 332 patients with melanoma. Patients had surgery to remove their tumor. 86% of patients underwent scanning every 12 months. 14% of patients were scanned every 6 months. The average follow-up time was 61 months.

33% of patients developed metastasis. 78% of these patients had the metastasis first identified by scanning. 46% of all patients had a false positive scan. PET/CT scans (94%) were slightly better at identifying metastatic recurrence compared to CT scans (75%). 

This study showed that regular CT or PET/CT scans can help to identify metastasis early in patients with stage III resected melanoma.

This study was based on medical records. Information might have been incomplete. Only patients without metastasis at diagnosis were included. The study does not comment on any effects of exposing patients to radiation during scanning.