The impact of (18)F-FDG PET-CT scanning for staging and management of Merkel cell carcinoma: results from Westmead Hospital, Sydney, Australia.
BACKGROUND
Merkel cell carcinoma (MCC) is a rare cutaneous malignancy with high mortality. Positron emission tomography (PET) using (18)F-fluorodeoxyglucose (FDG) has been shown to be valuable in the management of many types of cancer, and the purpose of this work was to determine its utility for patients with MCC.


OBJECTIVE
We sought to evaluate the impact of (18)F-FDG PET with simultaneous computed tomography (PET-CT) on the staging and management of patients with MCC.


METHODS
We reviewed the medical records of 18 patients with MCC who underwent 21 PET-CT scans at our institution from 2006 to 2008. The impact of PET-CT on staging and management plans were evaluated.


RESULTS
There were 12 men and 6 women with median age of 79 years (range, 54 to 85 years). All proven sites of MCC greater than 5 mm were positive on PET-CT with average maximum standardized uptake values (SUV max) of 4 in primary lesions, 5.6 in nodal disease and 11.5 in distant metastases. PET-CT contributed to altered staging in 7 patients (33%) and a change in management in 9 patients (43%). Two patients were found to have a second primary malignancy, but this did not alter management.


CONCLUSIONS
This was a retrospective review. Most patients had stage II or III disease, suggesting some potential referral bias.


CONCLUSIONS
(18)F-FDG PET-CT had a high impact in the management of MCC patients in our series and this investigation merits further assessment.
Concannon
Rebecca
R
Department of Nuclear Medicine & Ultrasound, Westmead Hospital, Westmead, Sydney, Australia.
Larcos
George S
GS
Department of Nuclear Medicine & Ultrasound, Westmead Hospital, Westmead, Sydney, Australia; Centre for Biomedical Imaging, Research & Development, Westmead Hospital, Westmead, Sydney, Australia; University of Sydney, Sydney, Australia.
Veness
Michael
M
Department of Radiation Oncology, Westmead Hospital, Westmead, Sydney, Australia; University of Sydney, Sydney, Australia. Electronic address: Michael.veness@swahs.health.nsw.gov.au.
D000368:Aged; D000369:Aged, 80 and over; D015266:Carcinoma, Merkel Cell / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy*; D003131:Combined Modality Therapy; D005260:Female; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000628:therapy; D009367:Neoplasm Staging / Q000379:methods*; D009517:New South Wales; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012878:Skin Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy*; D014057:Tomography, X-Ray Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18