The role of FDG-PET in the management of non-small cell lung carcinoma.

INTRODUCTION: Positron emission tomography (PET) using 18F-2-fluoro-2 deoxy-D-glucose (FDG) has been widely investigated and used in the non-invasive imaging of malignancy. Non-small cell lung carcinoma (NSCLC) is one of the most common and best validated indications for an FDG-PET scan. This review examines the roles of FDG-PET in the management of NSCLC and attempts to identify emerging uses and possible future developments. MATERIALS AND METHODS: Literature review of English language literature indexed on Medline. RESULTS: There is strong evidence to support the clinical efficacy and cost effectiveness of FDG-PET in the characterisation of solitary pulmonary nodules and in the staging of NSCLC. In addition, there are emerging uses in radiotherapy planning, monitoring of treatment response and prognostication. CONCLUSIONS: FDG-PET plays an integral role in the management of NSCLC and it is likely to expand as evidence supporting additional roles in the management of NSCLC becomes available.

Optimal pinhole techniques for preoperative localization with Tc-99m MIBI for primary hyperparathyroidism.

PURPOSE: Technetium-99m-labeled 2-methoxyisobutylisonitrile (Tc-99m MIBI) has been used extensively to localize parathyroid adenomas before operation. Imaging techniques vary widely, and the aim of this study was to determine the optimal time of delayed imaging and the value of routine correlative pertechnetate thyroid imaging. MATERIALS AND METHODS: In this study, preoperative parathyroid localization was performed using pinhole anterior and oblique images (15 minutes and 2 and 4 hours after injection) with correlative pertechnetate thyroid images. Ninety-seven patients underwent dual- or triple-phase Tc-99m MIBI imaging and correlative pertechnetate thyroid imaging before surgery. Two nuclear medicine physicians blinded to the surgical findings interpreted all available images and various Tc-99m MIBI image combinations at 15 minutes alone; 15 minutes and 2 hours, 15 minutes and 4 hours; and 15 minutes and 2 and 4 hours each with and without correlative pertechnetate thyroid imaging. RESULTS: Ninety parathyroid adenomas were detected in 86 patients. The optimal results were achieved with 15-minute and 2- and 4-hour Tc-99m-MIBI images, with correlative thyroid scans resulting in a sensitivity rate of 88%. Fifteen-minute and 2-hour Tc-99m-MIBI images and correlative thyroid scans and 15-minute and 4-hour Tc-99m MIBI images and correlative thyroid scans produced similar results (sensitivity rate, 86% and 83%, respectively; P = not significant). Compared with all Tc-99m MIBI image combinations alone, the addition of the routine correlative thyroid scan significantly improved sensitivity and also improved reporter confidence in 45% of studies. CONCLUSIONS: Of the pinhole techniques compared, 15-minute and 2-hour Tc-99m MIBI images with correlative thyroid scanning may be the preferred imaging protocol, because this yields results similar to imaging for as long as 4 hours after injection in a shorter, more logistically acceptable imaging time.

The value of oblique pinhole images in pre-operative localisation with 99mTc-MIBI for primary hyperparathyroidism.

Technetium-99m labelled 2-methoxyisobutylisonitrile (MIBI) has been extensively utilised for preoperative localisation of parathyroid adenomas. Imaging techniques have varied widely, with many centres not performing routine oblique images; thus this study aimed to examine the value of routine oblique pinhole imaging. Ninety-two patients underwent pre-operative 99mTc-MIBI imaging including early and delayed anterior oblique pinhole images in addition to standard anterior pinhole images and a thyroid study prior to surgery for primary hyperparathyroidism. These studies were reviewed blindly comparing anterior and oblique images and anterior images only in relation to surgical findings. Of the 92 patients, 83 were found to have 86 parathyroid adenomas or parathyroid adenoma/hyperplasia at surgery. When compared to anterior images only, oblique views improved overall sensitivity from 76% to 88% (P<0.05), correctly localised 11 more adenomas than anterior images alone (13%) and improved the confidence of interpretation in 17 patients (20%). In conclusion, routine oblique pinhole views result in greater sensitivity and reporter confidence in pre-operative parathyroid localisation with 99mTc-MIBI.

An empirical method for the prediction of T-cell epitopes.

Identification of T-cell epitopes from foreign proteins is the current focus of much research. Methods using simple two or three position motifs have proved useful in epitope prediction for major histocompatibility complex (MHC) class I, but to date not for MHC class II molecules. We utilized data from pool sequence analysis of peptides eluted from two HLA-DR13 alleles to construct a computer algorithm for predicting the probability that a given sequence will be naturally processed and presented on these alleles. We assessed the ability of this method to predict known self-peptides from these DR-13 alleles, DRB1(*)1301 and *1302, as well as an immunodominant T-cell epitope. We also compared the predictions of this scoring procedure with the measured binding affinities of a panel of overlapping peptides from hepatitis B virus surface antigen. We concluded that this method may have wide application for the prediction of T-cell epitopes for both MHC class I and class II molecules.