Journal of nuclear medicine : official publication, Society of Nuclear Medicine
-
The histamine H(3) receptor is implicated in the pathophysiology of several central nervous system disorders. N-methyl-6-(3-cyclobutyl-2,3,4,5-tetrahydro-1H-benzo[d]azepin-7-yloxy)-nicotamide (GSK189254) is a highly potent, selective, and brain-penetrant H(3) receptor antagonist. Previous studies in the pig using PET have shown that (11)C-GSK189254 uptake in H(3)-rich regions of the brain can be blocked by the selective H(3) antagonist ciproxifan. The purpose of the present study was to evaluate (11)C-GSK189254 as a PET radioligand for human studies and to determine the dose-receptor occupancy relationship of GSK189254 in the human brain. ⋯ (11)C-GSK189254 can be used to quantify H(3) receptor availability in humans in vivo using PET but requires high specific activity; the possibility of tracer mass dose effects should be carefully analyzed.
-
Comparative Study
1-11C-acetate versus 18F-FDG PET in detection of meningioma and monitoring the effect of gamma-knife radiosurgery.
This study aimed to define the potential of 1-(11)C-acetate PET, compared with (18)F-FDG, in detecting meningiomas and monitoring the effect of gamma-knife radiosurgery. ⋯ 1-(11)C-acetate was found to be useful for detecting meningiomas and evaluating the extent of meningiomas and potentially useful for monitoring tumor response to radiosurgery. However, 1-(11)C-acetate was not useful for evaluating the tumor grade. (18)F-FDG was found to be less useful than 1-(11)C-acetate for evaluating the extent of meningiomas and the response to radiosurgical treatment but may be useful for differentiating benign from malignant meningiomas. (18)F-FDG and 1-(11)C-acetate are complementary for assessing diverse cell metabolism of meningioma.
-
Clinical Trial
In vivo imaging of amyloid deposition in Alzheimer disease using the radioligand 18F-AV-45 (florbetapir [corrected] F 18).
An (18)F-labeled PET amyloid-beta (Abeta) imaging agent could facilitate the clinical evaluation of late-life cognitive impairment by providing an objective measure for Alzheimer disease (AD) pathology. Here we present the results of a clinical trial with (E)-4-(2-(6-(2-(2-(2-(18)F-fluoroethoxy)ethoxy)ethoxy)pyridin-3-yl)vinyl)-N-methyl benzenamine ((18)F-AV-45 or florbetapir [corrected] F 18). ⋯ (18)F-AV-45 was well tolerated, and PET showed significant discrimination between AD patients and HCs, using either a parametric reference region method (DVR) or a simplified SUVR calculated from 10 min of scanning 50-60 min after (18)F-AV-45 administration.
-
(111)In-diethylenetriaminepentaacetic acid (DTPA)-octreotide scintigraphy is currently the nuclear medicine imaging modality of choice for identifying neuroendocrine tumors. However, there are cohorts of patients in whom scintigraphy findings are negative or equivocal. We evaluated the role of (68)Ga-DOTATATE PET in a selected group of patients with negative or weakly positive findings on (111)In-DTPA-octreotide scintigraphy to determine whether (68)Ga-DOTATATE PET is able to detect additional disease and, if so, whether patient management is altered. ⋯ In patients with negative or equivocal (111)In-DTPA-octreotide findings, (68)Ga-DOTATATE PET identifies additional lesions and may alter management in most cases.
-
Comparative Study
Functional imaging of neuroendocrine tumors: a head-to-head comparison of somatostatin receptor scintigraphy, 123I-MIBG scintigraphy, and 18F-FDG PET.
Functional techniques are playing a pivotal role in the imaging of cancer today. Our aim was to compare, on a head-to-head basis, 3 functional imaging techniques in patients with histologically verified neuroendocrine tumors: somatostatin receptor scintigraphy (SRS) with (111)In-diethylenetriaminepentaacetic acid-octreotide, scintigraphy with (123)I-metaiodobenzylguanidine (MIBG), and (18)F-FDG PET. ⋯ The overall sensitivity of (123)I-MIBG scintigraphy and (18)F-FDG PET was low compared with SRS. However, for tumors with a high proliferation rate, (18)F-FDG PET had the highest sensitivity. The results indicate that, although SRS should still be the routine method, (18)F-FDG PET provides complementary diagnostic information and is of value for neuroendocrine tumor patients with negative SRS findings or a high proliferation index.