18F-FDG PET/CT in myeloma with presumed solitary plasmocytoma of bone.
OBJECTIVE
To evaluate the value of 18F-fluorodeoxy-glucose (FDG) positron emission tomography with computed tomography (PET/CT) in myeloma in patients presenting with a solitary plasmacytoma of bone (SPB).


METHODS
Fourteen consecutive patients studied since 2006, all having a diagnosis of SPB before PET/CT imaging took part in this study. In 3 patients PET/CT was performed for staging while in the remaining 11 it was used to monitor therapy. PET/CT was performed using a dedicated tomograph 60-90 minutes after intravenous injection of 53 MBq/kg of 18F-FDG and the results were compared to other diagnostic procedures [radiographs and magnetic resonance imaging (MRI)], biopsy, and other available follow-up data.


RESULTS
In 8/14 patients, PET/CT scans showed previously unsuspected sites of increased FDG accumulation. In 6/8 patients, FDG uptake was considered pathologic, depicting myeloma involvement in bone, while in the remaining cases, findings were considered incidental and not related to myeloma. PET findings attributed to myeloma were confirmed (i.e. true positives) in 6/6 cases (100%) and in all patients with findings reported as non-pathologic, myeloma was excluded (100% true negatives).


CONCLUSIONS
Our preliminary data in a small number of cases suggests that there are a group of patients with SPB (local disease) in whom FDG PET/CT may detect other unsuspected sites of bone involvement, upstaging the extent of the disease. In these cases, SPB may be a local manifestation of multiple myeloma where other sites of involvement have eluded detection by other less sensitive imaging modalities (i.e. skeletal surveys) or anatomically restricted imaging (i.e., less than total body MR or CT). Finding other sites of involvement have significant implications for appropriate treatment of myeloma.
Nanni
Cristina
C
Department of Nuclear Medicine, Policlinico S. Orsola-Malpighi, Bologna, Italy.
Rubello
Domenico
D
Zamagni
Elena
E
Castellucci
Paolo
P
Ambrosini
Valentina
V
Montini
Giancarlo
G
Cavo
Michele
M
Lodi
Filippo
F
Pettinato
Cinzia
C
Grassetto
Gaia
G
Franchi
Roberto
R
Gross
Milton D
MD
Fanti
Stefano
S
D000328:Adult; D000368:Aged; D000818:Animals; D001859:Bone Neoplasms / Q000150:complications* / Q000175:diagnosis / Q000000981:diagnostic imaging*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000150:complications* / Q000175:diagnosis / Q000000981:diagnostic imaging*; D010954:Plasmacytoma / Q000150:complications* / Q000175:diagnosis / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18