Multiple Myeloma: Molecular Imaging with 11C-Methionine PET/CT--Initial Experience.
OBJECTIVE
To prospectively assess molecular imaging of multiple myeloma (MM) by using the radiolabeled amino acid carbon 11 ((11)C) methionine and positron emission tomography (PET)/computed tomography (CT).


METHODS
The study was approved by the institutional local ethics committee and the national radiation protection authorities. All patients with MM and control patients gave written informed consent. Nineteen patients with MM (11 women, eight men; age range, 42-64 years) and 10 control patients with hyperparathyroidism without hematologic diseases (six women, four men; age range, 43-75 years) underwent PET/CT 20 minutes after injection of a mean of 1.0 GBq +/- 0.2 (standard deviation) (11)C-methionine. Presence and extent of CT-assessed tumor manifestations and (11)C-methionine bone marrow (BM) uptake were determined on the basis of maximum standardized uptake value (SUV(max)). BM imaging patterns, normal BM, and maximal lesion (11)C-methionine uptake in patients with MM were compared with those in control patients. In two patients with MM, sulfur 35 ((35)S) methionine uptake in freshly isolated BM plasma cells was measured. Values for SUV(max) of groups were compared by using the Mann-Whitney test on a per-patient basis.


RESULTS
(35)S-methionine uptake of plasma cells was five- to sixfold higher than in normal BM cells. (11)C-methionine BM uptake in control patients was homogeneous and low. All patients with MM except one with exclusively extramedullary myeloma had (11)C-methionine-positive lesions. Maximal lesion and normal BM (11)C-methionine mean SUV(max) were 10.2 +/- 3.5 and 4.3 +/- 2.0, respectively, and thus were significantly higher than that of BM in the control group (mean, 1.8 +/- 0.3; P < .001). Extramedullary MM was clearly visible in three patients (mean SUV(max), 7.2 +/- 2.4). Additional (11)C-methionine-positive lesions in normal cancellous bone were found in nearly all patients with MM. In pretreated patients with MM, a moderate fraction of osteolytic lesions had no (11)C-methionine uptake.


CONCLUSIONS
On the basis of increased methionine uptake in plasma cells, active MM can be imaged with (11)C-methionine PET/CT.
Dankerl
Anja
A
Department of Nuclear Medicine, University of Ulm, Robert-Koch-Strasse 8, D-89081 Ulm, Germany.
Liebisch
Peter
P
Glatting
Gerhard
G
Friesen
Claudia
C
Blumstein
Norbert M
NM
Kocot
Darius
D
Wendl
Christiane
C
Bunjes
Donald
D
Reske
Sven N
SN
D000328:Adult; D000368:Aged; D018906:Antineoplastic Agents, Alkylating / Q000627:therapeutic use; D001853:Bone Marrow / Q000000981:diagnostic imaging; D001842:Bone and Bones / Q000000981:diagnostic imaging; D002250:Carbon Radioisotopes; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006961:Hyperparathyroidism / Q000000981:diagnostic imaging; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008558:Melphalan / Q000627:therapeutic use; D008715:Methionine; D008875:Middle Aged; D009101:Multiple Myeloma / Q000175:diagnosis* / Q000188:drug therapy; D010014:Osteolysis / Q000000981:diagnostic imaging; D010950:Plasma Cells / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography / Q000379:methods*; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D013462:Sulfur Radioisotopes; D053668:Syndecan-1 / Q000032:analysis; D014057:Tomography, X-Ray Computed / Q000379:methods*
D018906:Antineoplastic Agents, Alkylating; D002250:Carbon Radioisotopes; D019275:Radiopharmaceuticals; D013462:Sulfur Radioisotopes; D053668:Syndecan-1; D008715:Methionine; D008558:Melphalan