Routine use of FDG-PET scans in melanoma patients with positive sentinel node biopsy.
OBJECTIVE
Positron emission tomography (PET) scanning is an efficient and well-known diagnostic tool in various malignant disorders. However, the utility of PET as a clinical routine screening procedure for the detection of subclinical metastases in stage III melanoma patients has not yet been established.


METHODS
Thirty-three patients with cutaneous malignant melanoma and subclinical lymph node metastases diagnosed by sentinel node biopsy (SNB) were submitted to( 18)F-fluoro-2-deoxy-D: -glucose (FDG) whole-body PET scanning within 100 days after SNB and wide local excision. Before PET scanning, patients were screened conventionally and found to be without evidence of further dissemination. Positive PET scan findings were evaluated by computed tomography scanning, magnetic resonance imaging and ultrasonography. Biopsy was performed whenever possible. The median follow-up was 15 months (range 6-39 months).


RESULTS
Nine patients (27%) had a positive PET scan performed after SNB and WLE. On verification, four cases (12%) were found to be true positive for melanoma metastasis and were thus upgraded from stage III to stage IV. Furthermore, one patient (3%) had another primary malignancy (prostate carcinoma), and two (6%) were found to have non-malignant lesions. Two PET-positive patients (6%) refused further investigations. In one case (3%) the PET scan was false negative. Twenty-three (69%) PET scans were true negative.


CONCLUSIONS
In a number of stage III melanoma patients with positive SNB, postoperative whole-body FDG-PET scanning revealed further melanoma dissemination not found by conventional screening methods and thus identified these cases as stage IV. Relevant therapy can accordingly be instituted earlier on the basis of FDG-PET scanning.
Department of Plastic Surgery, Roskilde County Hospital, Roskilde, Denmark.
Janne
J
Horn
Jørgen
J
Lock-Andersen
Helle
H
Sjøstrand
Annika
A
Loft
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D008545:Melanoma / Q000175:diagnosis* / Q000556:secondary*; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D051598:Whole Body Imaging / Q000379:methods*