Positron emission tomography/computed tomography to improve staging and restaging in Merkel cell carcinoma.

8552 Background: Merkel cell carcinoma (MCC) is a rare (~1,500 cases per year) and highly aggressive (33% mortality) cutaneous neuroendocrine carcinoma that occurs in older white patients on the UV-exposed skin of the head, neck, and extremities. As a patient’s stage at presentation is a strong predictor of survival, and there is a high propensity for locoregional recurrence and distant progression, imaging remains crucial for initial and subsequent management. There is, however, no consensus on the timing or method of imaging for MCC. Methods: We retrospectively reviewed 270 2-fluoro-[18F]-deoxy-2-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) scans performed in 97 patients at the Dana-Farber/Brigham and Women’s Cancer Center from August 2003 to December 2010. Results: The mean SUVmax was 6.5 for primary tumors, 6.4 for regional lymph nodes, 7.2 for distant metastases (all sites), 8.0 for bone/bone marrow metastases, and 9.4 for non-regional metastases in those patients with no...