A multicenter prospective evaluation of the clinical utility of F-18 FDG-PET/CT in patients with AJCC stage IIIB or IIIC extremity melanoma.
OBJECTIVE
There is a high risk of relapse in stage IIIB/IIIC melanoma. The utility of 2-[fluorine-18]-fluoro-2-deoxy-D-glucose positron emission tomography integrated with computed tomography (FDG-PET/CT) in these patients to evaluate response to treatment or for surveillance after treatment is currently not well defined.


METHODS
Prospective data from 2 centers identified 97 patients with stage IIIB/IIIC extremity melanoma undergoing isolated limb infusion (ILI) who had whole body FDG-PET/CT scans before and every 3 months after treatment. Clinical response was determined at 3 months by Response Evaluation Criteria In Solid Tumors.


RESULTS
Complete response (CR) after ILI occurred in 33% (32/97) of patients. FDG-PET/CT accurately identified 59% of patients who were CRs (19/32), whereas 41% (13/32) had residual metabolic activity in the extremity that was histologically negative for melanoma. The 3-year disease-free rate was 62.2% (95% CI: 40.1%-96.4%) for those patients who were CRs by both clinical/pathologic examination and FDG-PET/CT (n = 19) compared to only 29.4% (95% CI: 9.9%-87.2%) of those CRs who still had residual FDG-PET/CT activity (n = 13). FDG-PET/CT was utilized for surveillance of disease recurrence outside the regional field of treatment. Fifty-two percent (51/97) of patients developed disease outside the extremity at a median time of 212 days from pre-ILI FDG-PET/CT. In 47% (29/62) of these cases, the recurrence was resected.


CONCLUSIONS
Although FDG-PET/CT does not appear to accurately identify patients who appear to be CRs to ILI, it does appear to identify a subgroup of patients whose regional progression-free survival is markedly worse. However, FDG-PET/CT appears to be an excellent method for surveillance in stage IIIB/IIIC patients after ILI with ability to identify surgically resectable recurrent disease in these high-risk patients.
Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA.
Georgia M
GM
Beasley
Colin
C
Parsons
Gloria
G
Broadwater
M Angelica
MA
Selim
Suroosh
S
Marzban
Amy P
AP
Abernethy
April K S
AK
Salama
Edward A
EA
Eikman
Terence
T
Wong
Jonathan S
JS
Zager
Douglas S
DS
Tyler
D000328:Adult; D000368:Aged; D018450:Disease Progression; D018572:Disease-Free Survival; D005121:Extremities; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology; D008875:Middle Aged; D064847:Multimodal Imaging; D009367:Neoplasm Staging / Q000145:classification; D011159:Population Surveillance; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18