ABSTRACT
PURPOSE: The purpose of this study was to compare 2-[F-18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) and Tl-201 chloride (Tl) scintigraphy for detection of primary malignant bone and soft-tissue tumors. MATERIALS AND METHODS: A total of 40 patients with suspicion of malignant bone and soft-tissue tumors were examined. FDG PET imaging was performed at 1-hour post-FDG injection. Tl planar and single photon emission computed tomography images were acquired 10 minutes (early) and 2 hours (delayed) after injection of Tl. We evaluated FDG and Tl uptake visually and semiquantitatively using standardized uptake value and tumor to contralateral normal tissue ratio on planar images, respectively. RESULTS: Of the 33 patients with malignant tumors, all but 2 liposarcomas showed positive accumulation on FDG PET. However, all 7 benign lesions were also positive on FDG PET. Both early and delayed Tl images were positive for 27 of the 33 malignant tumors. Of the 6 false-negative cases on Tl images, 5 were liposarcomas. Both early and delayed Tl images were negative for 5 of the 7 benign lesions. The sensitivity of FDG PET for detection of primary malignant bone and soft-tissue tumors was 94% and the specificity, 0%. The corresponding values for Tl scintigraphy were 82% and 71%. The mean FDG standardized uptake value in malignant tumors was higher than that in benign lesions, but this difference was not statistically significant. Statistically significant differences were observed between malignant and benign lesions for both early and delayed tumor to contralateral normal tissue ratios. CONCLUSIONS: FDG PET was found to be more sensitive than Tl scintigraphy for primary malignant bone and soft-tissue tumors, although it was less specific.
Subject(s)
Bone Neoplasms/diagnostic imaging , Fluorodeoxyglucose F18 , Positron-Emission Tomography/methods , Soft Tissue Neoplasms/diagnostic imaging , Thallium Radioisotopes , Adolescent , Adult , Aged , Aged, 80 and over , Bone Neoplasms/pathology , Child , Female , Humans , Male , Middle Aged , Radiography , Retrospective Studies , Soft Tissue Neoplasms/pathology , Young AdultABSTRACT
PURPOSE: 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) positron emission tomography (PET) has been used as a promising tool to diagnose primary central nervous system (CNS) lymphoma because the tumor shows very high FDG accumulation. Although (11)C-methionine (MET) PET has been reported to be useful for evaluating various brain tumors, the role of MET PET in CNS lymphoma is unclear. We compared the uptake of MET and FDG in patients with CNS lymphoma. PROCEDURES: Thirteen immunocompetent patients with CNS lymphoma were examined. All patients underwent PET with MET (15 min p.i.) and FDG (60 min p.i.). PET results were evaluated by visual and semi-quantitative analysis. For semi-quantitative analysis, the standardized uptake value (SUV) and tumor to contralateral normal brain tissue (T/N) ratio were determined by region-of-interest analysis. RESULTS: For detection of CNS lymphoma, sensitivity of PET using both MET and FDG was 100%. The mean (±SD) value of SUV in the contralateral normal brain tissue using MET (1.43 ± 0.21) was significantly lower than that using FDG (5.58 ± 1.79; p < 0.002). The mean (±SD) value of SUV in the CNS lymphoma using MET (4.27 ± 1.91) was significantly lower than that of FDG (13.94 ± 5.65; p < 0.002). There were no significant differences between mean (±SD) T/N ratios using MET PET (3.00 ± 1.26) and FDG PET (2.74 ± 1.25). CONCLUSION: There was no significant difference between T/N ratios using MET PET and FDG PET, although uptake of MET in CNS lymphoma was significantly lower than that of FDG. MET PET showed as high a sensitivity as FDG PET for the detection of primary lesions in patients with CNS lymphoma.
