Search

Purpose: To assess the ability of positron emission tomography (PET) with 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) to allow differentiation of benign from malignant intraosseous lesions., Materials and Methods: Twenty patients with strictly intraosseous lesions (five benign and 15 malignant [three primary and 12 metastatic]) were studied with FDG PET. The final diagnosis was confirmed with histopathologic examination in all patients. The uptake of FDG within each lesion was evaluated qualitatively as well as semiquantitatively by determination of the standardized uptake value (SUV)., Results: SUV assessment of FDG accumulation within osseous lesions was superior to subjective visual analysis for discriminating benign from malignant lesions. With use of a 2.0 cutoff value for SUV, 14 of 15 malignant lesions were categorized correctly versus 12 of 15 correctly categorized by means of subjective image evaluation; four of five benign lesions were categorized correctly with both techniques., Conclusion: FDG PET can aid in differentiating benign from malignant strictly intraosseous lesions.

Unlabelled: The purpose of this study was to assess the results of PET with 16 alpha-[18F]fluoro-17 beta-estradiol (FES) and [18F]fluoro-2-deoxy-D-glucose (FDG) to validate the concordance between tumor estrogen-receptor (ER) status as determined by FES-PET and in vitro assays and to assess the relationship between tumor metabolic activity determined by FDG-PET and tumor ER status, both of which may provide information about tumor aggressiveness and prognosis., Methods: We studied 32 patients with primary breast masses and 21 patients with clinical or radiological evidence of recurrent/metastatic breast carcinoma. A diagnosis of breast carcinoma was subsequently proven in 43 patients (24 primary, 15 metastatic and 4 recurrent tumors). In vitro assessment of ER status was available for 40 malignant lesions (23 primary and 17 metastatic/recurrent). The patients underwent PET with both FES and FDG, and the uptake of each tracer within each lesion was evaluated qualitatively as well as semiquantitatively using the standardized-uptake-value (SUV) method., Results: We found good overall agreement (88%) between in vitro ER assays and FES-PET. This degree of agreement is similar to that observed between replicate in vitro assays (with discordances due to interlaboratory, interassay and specimen variability). We were, however, unable to demonstrate any significant relationship between tumor FDG uptake and ER status or between tumor FDG and tumor FES uptake in these patients., Conclusion: These results indicate that in vitro ER assays and/or FES-PET provide unique direct information about breast cancer ER status that cannot be obtained indirectly by FDG-PET.

Positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (FDG) was performed in 19 patients with brain metastases from non-central nervous system (CNS) neoplasms and one patient with a primary CNS lymphoma. Various histopathologic types were represented by the primary neoplasms in the patients with metastases. Only 21 of the 31 lesions (68%) were detected with FDG PET as discrete, metabolically active foci (relative to surrounding structures). Six of the nondetected lesions may have been nondiscernible owing to their small size and/or isointensity relative to closely apposed normal gray matter. However, four lesions of at least 1.2 cm in diameter showed frankly decreased FDG accumulation relative to normal brain. These findings suggest that studies of FDG accumulation by a variety of non-CNS neoplasms and their CNS metastases are in order and that extrapolation of the successes of FDG PET in imaging of primary glial tumors to imaging of brain metastases should proceed with caution.

Positron emission tomographic measurements of regional blood flow, a marker of local neuronal activity, were used to investigate the neuroanatomical correlates of a normal emotion. Healthy volunteers were studied before, during, and after anticipation of a painful electric shock. During anticipatory anxiety, there were significant blood flow increases in bilateral temporal poles, the same regions recently implicated in a lactate-induced anxiety attack in patients with panic disorder. Thus, the temporal poles seem to be involved in normal and pathological forms of human anxiety.

Positron emission tomographic measurements of regional blood flow were used to assess local neuronal activity in patients with panic disorder and in normal control subjects before and during the infusion of sodium lactate. A new technique for the analysis of positron emission tomographic data was employed to identify significant changes in regional blood flow associated with lactate infusion in the panicking patients, nonpanicking patients, and controls. Lactate-induced panic was associated with significant blood flow increases bilaterally in the temporal poles; bilaterally in insular cortex, claustrum, or lateral putamen; bilaterally in or near the superior colliculus; and in or near the left anterior cerebellar vermis. Lactate infusion was not associated with significant changes in regional blood flow in the nonpanicking patients or control subjects. Thus, the identified regions seemed to be involved in an anxiety attack.