ABSTRACT
Purpose: Positron Emission Tomography (PET) using 18F-Fluorodeoxyglucose (18FDG) has been extensively used to stage patients with different malignancies. The purpose of our study was to compare 18FDG-PET to Computed Tomography (CT) in the management of patients with malignant mesothelioma.Methods: Eight patients (6 males, 2 females; mean age 67, range 53 to 78 years) underwent 18FDG-PET scan between March 1997 and November 1998. PET scan of the neck, thorax and upper abdomen was performed 45 minutes after the intravenous injection of 10 mCi of FDG in fasted patients; attenuation correction was applied in all cases. The findings were compared with CT and pathology.Results: PET and CT were concordant in 3 patients. PET was superior to CT in 5 cases (1 patient was downgraded from widespread to localized disease, 2 patients were upstaged from localized to widespread disease, PET confirmed equivocal findings by CT in 2 cases). In 1 patient PET and CT missed local spread of tumor to diaphragm and pericardium, showing instead disease confined to pleural space.Conclusions: Our results suggest that PET is more accurate than CT in the staging of patients with mesothelioma.
ABSTRACT
Purpose: The frequency of adrenal metastases from non-small cell lung cancer (NSCLC) varies between 4 to 25%. Adrenal metastases are frequently missed (78%) by Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). The purpose of this study was to characterize the patterns of adrenal gland involvement from lung cancer by 18-F-Fluorodeoxyglucose Positron Emission Tomography (18FDG-PET).Methods: Retrospective review of patients evaluated for known or suspected lung carcinoma. Results of 18FDG-PET, CT, MRI, and scans were compared.Results: From February 1996 to May 2000, 91 patients with known (85 patients) or suspected (6 patients) lung cancer were evaluated with 18FDG-PET scan. Twenty-two patients (mean age 63, range 38-88 years) had abnormal adrenal glands by either 18FDG-PET (16 patients), CT (12 patients) or MRI (1 patient). In 13 cases 18FDG-PET scan was ordered to clarify CT or MRI findings. Only 7 patients showed adrenal gland involvement: 5 patients (5.5%) with unilateral disease and 2 patients (2.2%) with bilateral disease. PET depicted unsuspected findings in 9 patients: 8 patients (8.8%) with unilateral disease and 1 patient (1.1%) with bilateral disease.(18)FDG-PET upstaged 9 patients from limited (N1M0) to widespread disease (M1), thus obviating surgical intervention.Conclusion: This study demonstrates the potential of 18FDG-PET scanning in revealing unsuspected adrenal metastases in patients with early stages of NSCLC as well as characterizing CT or MRI equivocal adrenal masses.
ABSTRACT
Purpose: Positron Emission Tomography with 18F-Fluorodeoxyglucose (18FDG-PET) is becoming the noninvasive test of choice to evaluate patients with single pulmonary nodules (SPN). While positive scans yield a high sensitivity for malignancy, the significance of negative scans remains unclear. The purpose of this study was to evaluate the prognostic value of negative 18FDG-PET in patients with SPN.Methods: From January 1998 to January 2000, 59 patients with non-calcified parenchymal SPN underwent 18FDG-PET evaluations. From a total of 14 pathologically proven tumors 12 patients had positive 18FDG-PET scans (sensitivity 86%, PPV 100%) with a mean SUV of 5.6. A total of 24 patients (41%) with negative 18FDG-PET scans were followed up with serial chest x-ray (CXR) and/or Computed tomography (CT) for a period of 6 to 24 months (mean 10.4 months). Histology specimens were available in 5 patients. Two patients had a second PET scan.Results: Nineteen of the 24 negative 18FDG-PET patients (79.2%) had no evidence of intrathoracic neoplasia at subsequent follow up by CT and/or CXR, for an overall NPV of 86.3%. Two patients (8.3%) had transthoracic needle biopsies that were positive for malignancy after the PET scan. The remaining 3 patients developed intrathoracic malignancies during the follow up period (6, 6, and 9 months respectively) by CT and/or CXR. Repeat 18FDG-PET scans were positive in 2 patients.Conclusion: 18FDG-PET appears to effectively characterize patients at low risk for malignant transformation of SPN discovered by CT. Blinded, randomized controlled trials are needed for further evaluation.
ABSTRACT
Cyclodiene insecticides, hexachlorocyclohexanes, pyrethroids, bicyclophosphates, the bicycloorthocarboxylate insecticides and some of their metabolites and environmental degradation products are central nervous system toxicants with high specific binding affinity to the chloride channel of the gamma-aminobutyric acid (GABA)A receptor-ionophore sites. [35S] tertiary-butylbicyclophosphorothionate (TBPS) with specific activity higher than 60 Ci/mmole has a high binding affinity to the same sites and is now commercially available and can be used to label the GABAA receptor for the development of a radioreceptor assay technique. The GABA receptor was prepared by ultra centrifugation and dialysis of brain homogenates of either cow, goat, rat or catfish. The receptor was then labeled with [35S] TBPS and the assay was conducted by measuring the displacement of radioactivity following incubation with samples containing the analytes. A radioreceptor assay protocol was developed to measure the amount of the alpha-endosulfan in blood samples. The assay was extremely sensitive, and can detect 0.2 nM of endosulfan at a level equivalent to 0.08 ppb or 8 x 10(-11) gm of endosulfan in each ml of the blood samples.
