Journal of nuclear medicine : official publication, Society of Nuclear Medicine
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Limited blood volume in mice precludes repeated sampling, rendering a reliable image-derived input function (IDIF) desirable for quantification of glucose uptake. We aimed to compare different IDIF volumes and to evaluate the effects of changing fit time interval on Patlak uptake kinetics in hearts of healthy mice. ⋯ The choice of IDIF has a profound effect on Patlak kinetics and calculated 18F-FDG uptake. Adjustment of the time interval for fit may be necessary for accurate calculations, particularly with acute insulin treatment. Even without partial-volume correction, the inferior vena cava provides a reliable and reproducible IDIF for Patlak analysis of myocardial glucose uptake in mice.
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Imaging and therapy using radioligands targeting receptors overexpressed on tumor cells is successfully applied in neuroendocrine tumor patients. Because expression of the gastrin-releasing peptide receptor (GRPR), somatostatin receptor 2 (SSTR2), and chemokine C-X-C motif receptor 4 (CXCR4) has been demonstrated in breast cancer, targeting these receptors using radioligands might offer new imaging and therapeutic opportunities for breast cancer patients. The aim of this study was to correlate messenger RNA (mRNA) expression of GRPR, SSTR2, and CXCR4 with clinicopathologic and biologic factors, and with prognosis and prediction to therapy response, in order to identify specific breast cancer patient groups suited for the application of radioligands targeting these receptors. ⋯ Our data indicate that imaging and therapy using GRPR or SSTR2 radioligands might especially be beneficial for ESR1-positive breast cancer and CXCR4 radioligands for ESR1-negative breast cancer.
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Early prognostic stratification is desirable in patients with suspected atypical parkinsonian syndromes (APSs) for optimal treatment and counseling. We investigated the prognostic value of imaging disease-specific metabolism patterns with 18F-FDG PET compared with that of clinical diagnosis. ⋯ 18F-FDG PET is an early predictor of survival in patients with clinically suspected APS. Detection of cortical or subcortical hypometabolism by 18F-FDG PET is an unfavorable predictor. Risk stratification by 18F-FDG PET appears to be at least as predictive as the 1-y follow-up clinical diagnosis. This finding strongly supports the early inclusion of PET imaging in patient care.