PRIMARY STAGING AND FOLLOW-UP OF HIGH-RISK MELANOMA PATIENTS WITH WHOLE-BODY F-18 FLUORODEOXYGLUCOSE POSITRON-EMISSION-TOMOGRAPHY - RESULTSOF A PROSPECTIVE-STUDY OF 100 PATIENTS

BACKGROUND. Positron emission tomography (PET) has been retrospectivel y reported to be a sensitive method for detecting malignant melanoma m etastases. METHODS. One hundred consecutive patients with high risk me lanoma (tumor thickness >1.5 mm) were prospectively evaluated (52 at p rimary diagnosis, comprising Group A, and 48 during follow-up, compris ing Group B) by whole-body PET and conventional diagnostics (CD). RESU LTS. In Group A, the sensitivity of PET was 100% and the specificity w as 94%, whereas CD did not identify any of the 9 lymph node metastases and demonstrated a lower specificity (80%). In Group B, 121 lesions w ere detected, 111 by PET and 69 by conventional imaging. On the basis of patients, the sensitivity, specificity, and accuracy of PET were 10 0%, 95.5%, and 97.9%, respectively (91.8%, 94.4%, and 92.1%, respectiv ely, on the basis of single metastases). Prospectively, CD did not ide ntify all patients with progression (sensitivity, 84.6%) and detected significantly fewer metastases (sensitivity, 57.5%) with much lower sp ecificity (68.2% on the basis of patients, 45% on the basis of single lesions); therefore, the accuracy of CD was 77.1% on the basis of pati ents and only 55.7% on the basis of single metastases. Results also de pended on specific sites: while PET yielded a higher sensitivity in de tecting cervical metastases (100% vs, 66.6%) and abdominal metastases (100% vs. 26.6%), computed tomography proved to be superior in detecti ng small lung metastases (87% vs. 69.6%). CONCLUSIONS. PET is a highly sensitive and specific technique for melanoma staging. With the excep tion of the brain, one single whole-body F-18-fluorodeoxyglucose-PET s can could replace the standard battery of imaging tests currently perf ormed on high risk melanoma patients. (C) 1998 American Cancer Society .