Journal of nuclear medicine : official publication, Society of Nuclear Medicine
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Comparative Study
Absolute quantification of regional cerebral glucose utilization in mice by 18F-FDG small animal PET scanning and 2-14C-DG autoradiography.
The purpose of this study was to evaluate the feasibility of absolute quantification of regional cerebral glucose utilization (rCMR(glc)) in mice by use of (18)F-FDG and a small animal PET scanner. rCMR(glc) determined with (18)F-FDG PET was compared with values determined simultaneously by the autoradiographic 2-(14)C-DG method. In addition, we compared the rCMR(glc) values under isoflurane, ketamine and xylazine anesthesia, and awake states. ⋯ We were able to obtain accurate absolute quantification of rCMR(glc) with mouse (18)F-FDG PET imaging as confirmed by concurrent use of the autoradiographic 2-(14)C-DG method. Underestimation of rCMR(glc) by (18)F-FDG in normoglycemic conditions may be due to partial-volume effects. Computation of rCMR(glc) from (18)F-FDG data in hyperglycemic animals may require, however, alternative rate and lumped constants for (18)F-FDG.
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Clinical Trial
Simultaneous assessment of gastric accommodation and emptying: studies with liquid and solid meals.
The aim of this study was to develop a scintigraphic test to measure gastric emptying and accommodation simultaneously. ⋯ This method permits simultaneous measurement of gastric emptying and accommodation. In healthy subjects, the gastric accommodation response is prolonged and persists despite nearly complete emptying of a liquid or solid meal.
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Clinical Trial
Use of stereotactic PET images in dosimetry planning of radiosurgery for brain tumors: clinical experience and proposed classification.
We developed a technique that allows the routine integration of PET in stereotactic neurosurgery, including radiosurgery. We report our clinical experience with the combined use of metabolic (i.e., PET) and anatomic (i.e., MRI and CT) images for the radiosurgical treatment of brain tumors. We propose a classification describing the relative role of the information provided by PET in this multimodality image-guided approach. ⋯ The integration of PET in radiosurgery provides additional information that opens new perspectives for the optimization of the treatment of brain tumors.
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Therapeutic efficacy in radioimmunotherapy depends, among other things, on the choice of the radionuclide. The aim of the present study was to determine the most suitable radionuclide for radioimmunotherapy with monoclonal antibody MN-14 to carcinoembryonic antigen in an experimental model of small peritoneal metastases of colorectal origin. ⋯ The uptake of (88)Y-MN-14 in small peritoneal LS174T xenografts was higher than the uptake of (131)I-MN-14 or (186)Re-MN-14. The present study indicates that (131)I and (177)Lu are the most suitable radionuclides for the radioimmunotherapy of small peritoneal metastases.
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The therapeutic effects of peptide receptor-based radionuclide therapy are extensively being investigated in rats bearing tumors. Both the dose to the tumor and the therapy-limiting dose to normal tissues, such as kidneys and bone marrow, are of interest for these preclinical studies. The aim of this work was to develop a generalized computational model for internal dosimetry in rats. ⋯ The renal dose of 70-95 Gy for an injected activity of 555 MBq will likely cause radiation damage, although the higher amount of peptide with this activity may influence the dosimetry by partial receptor saturation. Dose volume histograms show that (111)In and (177)Lu are likely to have a higher threshold for renal damage than (90)Y.