AJR:198, April 2012
Yulia Bronstein Chaan S. Ng Eric Rohren Merrick I.Ross Jeffrey E. Lee Janice Cormier Valen E. Johnson Wen-Jen Hwu
OBJECTIVE. The purpose ofthis article is to determine how often unexpected 18F-FDG PET/CT findings result in a change in management for patients with stage IV and clinically evident stage III melanoma with resectable disease according to conventional imaging.
SUBJECTS AND METHODS. Thirty-two patients with oligometastatic stage IV and clinically evident stage III melanoma were identified by surgical oncologists according to the results of conventional imaging, which included contrast-enhanced CT of the chest, abdomen, and pelvis and MRI of the brain. The surgical plan included resection of known metastases or isolated limb perfusion with chemotherapy. Thirty-three FDG PET/CT scans were performed within 36 days of their contrast-enhanced CT. The impact of PET/CT was defined as the percentage of cases in which a change in the surgical plan resulted from the unanticipated PET/CT findings.
RESULTS. PET/CT revealed unexpected melanoma metastases in 12% of scans (4/33). As a result, the surgery was canceled for two patients, and the planned approach was altered for another two patients to address the unexpected sites. In 6% of scans (2/33), the unexpected metastases were detected in the extremities, which were not included in conventional imaging. Three scans (9%) showed false-positive FDG-avid findings that proved to be benign by subsequent stability or resolution with no therapy.
CONCLUSION. In patients with surgically treatable metastatic melanoma, FDG PET/ CT can detect unexpected metastases that are missed or not imaged with conventional imaging, and can be considered as part of preoperative workup.