Journal of nuclear medicine : official publication, Society of Nuclear Medicine
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Review Comparative Study
Of mice and humans: are they the same?--Implications in cancer translational research.
Animal models have been instrumental in elucidating key biochemical and physiologic processes of cancer onset and propagation in a living organism. Most importantly, they have served as a surrogate for patients in the evaluation of novel diagnostic and therapeutic anticancer drugs, including radiopharmaceuticals. Experimental tumors raised in rodents constitute the major preclinical tool of new-agent screening before clinical testing. ⋯ Differences in size and physiology, as well as variations in the homology of targets between mice and humans, may lead to translational limitations. Other factors affecting the predictive power of preclinical models may be animal handling during experimentation and suboptimal compilation and interpretation of preclinical data. However, animal models will remain a unique source of in vivo information and the irreplaceable link between in vitro studies and our patients.
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Regional specific lung volume change (sVol), defined as the regional tidal volume divided by the regional end-expiratory gas volume, is a key variable in lung mechanics and in the pathogenesis of ventilator-induced lung injury. Despite the usefulness of PET to study regional lung function, there is no established method to assess sVol with PET. We present a method to measure sVol from respiratory-gated PET images of inhaled (13)N-nitrogen ((13)NN), validate the method against regional specific ventilation (sV), and study the effect of region-of-interest (ROI) volume and orientation on the sVol-sV relationship. ⋯ sVol can be computed with PET using the proposed method and is highly correlated with sV. Errors in sVol are smaller for larger ROIs and for orientations based on the ventrodorsal axis.
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Clinical Trial
Measuring tumor cell proliferation with 18F-FLT PET during radiotherapy of esophageal squamous cell carcinoma: a pilot clinical study.
The primary aim of this study was to use serial (18)F-3'-deoxy-3'-fluorothymidine (FLT) PET/CT to measure tumor cell proliferation during radiotherapy of squamous cell carcinoma (SCC) of the esophagus. ⋯ (18)F-FLT uptake can be used to monitor the biologic response of esophageal SCC and normal tissue to radiotherapy. Increased uptake of (18)F-FLT after treatment interruptions may reflect accelerated repopulation. (18)F-FLT PET/CT may have an advantage over (18)F-FDG PET/CT in differentiating inflammation from tumor.