Whole-body (18)F-FDG PET identifies high-risk myeloma.
The purpose of this study was to evaluate the clinical utility of whole-body PET with (18)F-FDG in patients with multiple myeloma and related monoclonal diseases.


METHODS
Between July 1, 1996, and July 2000, 98 (18)F-FDG PET scans were obtained for 66 patients, with 25 patients having 2 or more scans. The results were compared with routine clinical and staging information, including CT and MRI scans, as indicated. Of the 66 patients, 16 had previously untreated active myeloma, 14 had monoclonal gammopathy of undetermined significance (MGUS), 10 had disease in remission, and 26 had relapsing disease.


RESULTS
Negative whole-body (18)F-FDG PET findings reliably predicted stable MGUS. Of the 14 MGUS patients with follow-up of 3-43+ mo, myeloma has developed in only 1 (7%), at 8 mo. Conversely, the 16 previously untreated patients with active myeloma all had focal or diffusely positive scan findings. Four (25%) of 16 previously untreated patients with positive (18)F-FDG PET findings had negative full radiologic surveys. Another 4 (25%) of 16 patients had focal extramedullary disease. This was confirmed by biopsy or other imaging techniques. Extramedullary uptake also occurred in 6 (23%) of 26 patients with relapse. This extramedullary uptake was a very poor prognostic factor both before treatment and at relapse. For example, median survival was 7 mo for patients with disease relapse. Persistent positive (18)F-FDG PET findings after induction therapy predicted early relapse. In 13 (81%) of 16 patients with relapsing disease, new sites of disease were identified. The (18)F-FDG PET results were especially helpful in identifying focal recurrent disease in patients with nonsecretory or hyposecretory disease amenable to local irradiation therapy, which was used in 6 patients.


CONCLUSIONS
Whole-body (18)F-FDG PET provides important prognostic information, which is clinically useful and complementary to conventional methods of evaluating plasma cell disorders. (18)F-FDG PET is a unique tool for evaluation of nonsecretory myeloma. Residual or recurrent disease after therapy, especially extramedullary disease, is a poor prognostic factor.
Durie
Brian G M
BG
Division of Hematology/Oncology, Department of Medicine, Cedars-Sinai Comprehensive Cancer Center, Cedars-Sinai Medical Center, Los Angeles, California, USA. bdurie@salick.com
Waxman
Alan D
AD
D'Agnolo
Allesandro
A
Williams
Cindy M
CM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018450:Disease Progression; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000000981:diagnostic imaging*; D010265:Paraproteinemias / Q000000981:diagnostic imaging; D010954:Plasmacytoma / Q000000981:diagnostic imaging*; D011379:Prognosis; D019275:Radiopharmaceuticals; D012008:Recurrence; D012074:Remission Induction; D012189:Retrospective Studies; D012307:Risk Factors; D014055:Tomography, Emission-Computed; D015899:Tomography, Emission-Computed, Single-Photon
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18