18F-FDG-PET/CT in the Staging and Management of Melanoma A Prospective Multicenter Ontario PET Registry Study

Purpose The Ontario PET Registry was established to provide evidence on the clinical impact of 18-FDG-PET/CT (PET) imaging to inform Ontario Health Insurance Plan funding decisions. The melanoma registry assessed the use of melanoma staging by PET in advanced or high-risk melanoma as a useful adjunct to clinical and standard radiologic investigation. Materials and Methods Between January 2011 and July 2013, approximately 319 consecutive patients with potentially resectable localized high-risk melanoma or recurrent disease under consideration for metastasectomy underwent PET imaging for staging across 9 institutions in Ontario. Pre-PET stage information was provided by the referring clinician and compared with post-PET stage. The ability of PET to reclassify disease from M0 to M1 status was assessed. The registry data were then linked to provincial administrative databases using deidentified health insurance numbers to determine PET stage-based rates of systemic therapy, radiotherapy, and surgery. Results There was a significant increase in stage to M1 status after PET in 56 of 319 patients (17.6%) (P < 0.0001). There was no significant relationship between upstaging with PET and the proportion of patients receiving radiation therapy (P = 0.066) or systemic therapy (P = 0.072). There was a significant relationship between upstaging with PET and the proportion of patients undergoing surgical resection of metastases distant to the primary melanoma site (P = 0.034). Conclusions This prospective, multicenter registry of high-risk or advanced melanoma found that PET significantly upstages patients and impacts surgical management.