BY David Douglas
NEW YORK (ReutersHealth) Oct 12 - In staging melanoma patients with palpable lymphnodes, 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) and computed tomography (CT) are equivalent, but FDG-PET detects moremetastatic sites, particularly bone and subcutaneous metastases, Dutch researchers report in the October 1st issue the Journal of ClinicalOncology.
Dr. Harald J. Hoekstra ofUniversity Medical Centre Groningen and colleagues came to theseconclusions after prospectively studying data on 251 patients whounderwent both FDG-PET and CT at five centers.
Distantmetastases were suggested by FDG-PET in 32% of the patients and by CT in 29%. After correlation with cytology and histology or 6 months offollow-up, results proved correct in 27% of FDG-PET scans and 24% of CTscans.
The article notes that results werecorrect in 68 of 79 patients (86%) with positive FDG-PET scans and in61 of 72 (85%) with positive CT scans.
False positive rates were not statistically different between hospitals, according to the researchers.
Significantlymore sites were detected with FDG-PET than with CT (133 versus 112).This was particularly the case for bone metastases (27 versus 10) andsubcutaneous metastases (11 versus 5).
Treatmentchanged in 19% of the patients. In most of these cases (79%), therapywas changed on the basis of both scans. Changes were made solely aresult of FDG-PET in 17%, and solely a result of CT in 4%.
Theresearchers also calculated that FDG-PET provided value in addition tothat of spiral CT in 17% of patients. Conversely, CT was of additionalvalue in 9% of the patients.
"Due to theimproved staging of melanoma patients with lymph node metastases," Dr.Hoekstra told Reuters Health, "surgical oncologists can better selectmelanoma patients for curative therapeutic lymph node dissection andrefer patients with distant disease to a medical oncologist forsystemic treatment."
Overall, he concluded, based on FDG-PET, "melanoma patients with lymph node metastases get the best tailored treatment."
J Clin Oncol 2009;27:4774-4780.