ABSTRACT
PURPOSE: 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). MATERIALS AND 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. CONCLUSION: On the basis of increased methionine uptake in plasma cells, active MM can be imaged with (11)C-methionine PET/CT.
Subject(s)
Carbon Radioisotopes , Multiple Myeloma/diagnosis , Positron-Emission Tomography/methods , Radiopharmaceuticals , Tomography, X-Ray Computed/methods , Adult , Aged , Antineoplastic Agents, Alkylating/therapeutic use , Bone Marrow/diagnostic imaging , Bone and Bones/diagnostic imaging , Cohort Studies , Female , Follow-Up Studies , Humans , Hyperparathyroidism/diagnostic imaging , Image Processing, Computer-Assisted/methods , Male , Melphalan/therapeutic use , Methionine , Middle Aged , Multiple Myeloma/drug therapy , Osteolysis/diagnostic imaging , Plasma Cells/diagnostic imaging , Prospective Studies , Sulfur Radioisotopes , Syndecan-1/analysisABSTRACT
The aim of this study was to evaluate the possible correlation between preoperative FDG-PET results in human breast cancer and the prognostic markers Ki-67, c- erb B2, p53, oestrogen/progesterone receptor status, axillary lymph node status, tumour size and tumour grading. Seventy-five female patients with breast cancer were included in this prospective study. Patient selection was independent of tumour size and the suspected clinical stage of disease. A high-resolution full-ring scanner (Siemens ECAT HR+) was used for PET imaging. The FDG uptake of breast tumours was calculated as the tumour to background ratio (TBR). In resected cancer tissue specimens, the proliferative fraction was evaluated by Ki-67 immunostaining. Additionally, immunostaining of the prognostic markers c-erb B2, p53, and progesterone and oestrogen receptors was performed. Haematoxylin and eosin-stained sections were used for tumour grading. Correlations between FDG uptake and prognostic markers were assumed to be significant at P<0.05 using the Mann-Whitney U test. In ductal breast cancer, mean TBR was 17.3 (median 7.7, range 1.6-122.7), while in lobular cancer it was 6.5 (median 3.7, range 1.4-22.7). Mean proliferative fraction (% Ki-67 positive tumour cells) was 15%+/-13.8% (median 10%, range 0%-60%). Twenty-three carcinomas showed <5% Ki-67 positive tumour cells. Statistical analysis indicated a positive correlation between FDG uptake and proliferative index in ductal breast cancer ( P<0.0001, r=0.63). By contrast, there was no correlation between FDG uptake and c- erb B2 ( P=0.79), p53 ( P=0.92), tumour grading ( P=0.09), oestrogen receptor status ( P=0.41), progesterone receptor status ( P=0.34), axillary lymph node status ( P=0.90) and tumour size ( P=0.3). It is concluded that FDG uptake is significantly higher in ductal breast cancer than in lobular cancer ( P<0.05). FDG uptake correlates with proliferative activity assessed by Ki-67 immunostaining ( P<0.05). A significant correlation with the other prognostic markers, however, could not be demonstrated.
