Cost-Effectiveness of Positron Emission Tomography in Breast Cancer

PURPOSE: In this study, we used quantitative decision tree modeling to assess the cost-effectiveness of a positron emission tomography (PET)-based management scenario for breast cancer in Canada. PROCEDURES: Two patient management scenarios were compared (with and without PET). A metaanalysis of studies for the accuracy of PET in staging breast cancer was conducted. Life expectancies were calculated. Management costs were determined from previous cost-effective analyses, management costs from our institutions, and recently published Canadian cost estimates of various procedures. RESULTS: A cost savings of $695 per person is expected for the PET strategy, with an increase in life expectancy (7.4 days), when compared with the non-PET strategy. This cost savings remained in favor of the PET strategy when subjected to a sensitivity analysis. CONCLUSIONS: The use of a PET management strategy for the staging of breast cancer is expected to remain economically viable in Canada under various economic conditions.     

Cardiac Positron Emission Tomography: a Clinical Perspective

Cardiac positron emission tomography is a powerful, quantitative, non-invasive imaging modality, which adds valuable diagnostic and prognostic information to the clinical work-up. Myocardial perfusion and viability imaging are, as a result of continuously growing evidence, established clinical indications that may be cost-effective, due to the high diagnostic accuracy of cardiac positron emission tomography, despite high single-test costs. In the field of inflammation imaging, new indications are entering the clinical arena, which may contribute to a better diagnosis and overall patient care, as for instance in patients with cardiac sarcoidosis, prosthetic valve endocarditis and cardiac device infections. This review will discuss the individual strengths and weaknesses of cardiac positron emission tomography and, hence, the resulting clinical usefulness based on the current evidence for an individualized, patient-centered imaging approach.     

Positron Emission Tomography Studies in Headache

Positron emission tomography (PET) allows the quantitative measurement of regional cerebral flow (rCBF) in humans in quantitative terms. Gross changes in rCBF are due to variation in vessel diameter. Changes of rCBF also reflect synaptic activity (inhibition and excitation). Therefore, PET was used to monitor changes in blood flow during the aura and headache phase of a migraine attack and to investigate focal areas of increased or decreased blood flow, eg, in the brain stem and midbrain. Hemispheric rCBF was unchanged in spontaneous migraine attacks without aura. This was true for the headache side as well as for the nonheadache side. Sumatriptan had no effects on cerebral blood flow. Regional cerebral blood flow was increased in midline brain stem structures during the headache phase, but also when the headache had been treated with sumatriptan. This persisting increased activity might reflect activity of a presumed migraine center in the brain stem. These changes are specific for migraine attacks and are not seen during attacks of cluster headache. Positron emission tomography measurements in the early phase of a migraine attack in a single subject showed flow reductions in the occipital cortex spreading forwards; an observation which would be compatible with the existence of spreading depression in humans. Our attempts to study the aura phase with PET have, to date, been unsuccessful.     

PET在神经外科的应用

复习有关正电子发射断层显像术(PET)文献资料,分析归纳PET对脑瘤、癫痫、帕金森氏病等的放射学特点和诊疗效果,提倡临床积极应用PET。     

Translational Neuroimaging: Positron Emission Tomography Studies of Monoamine Oxidase

Positron emission tomography (PET) using radiotracers with high molecular specificity is an important scientific tool in studies of monoamine oxidase (MAO), an important enzyme in the regulation of the neurotransmitters dopamine, norepinephrine, and serotonin as well as the dietary amine, tyramine. MAO occurs in two different subtypes, MAO A and MAO B, which have different substrate and inhibitor specificity and which are different gene products. The highly variable subtype distribution with different species makes human studies of special value. MAO A and B can be imaged in the human brain and certain peripheral organs using PET and carbon-11 (half-life 20.4 minutes) labeled mechanism-based irreversible inhibitors, clorgyline and l-deprenyl, respectively. In this article we introduce MAO and describe the development of these radiotracers and their translation from preclinical studies to the investigation of variables affecting MAO in the human brain and peripheral organs.     

Noninvasive Positron Emission Tomography Imaging of Coronary Arterial Inflammation

The importance of inflammation to atherothrombosis has led to the pursuit of noninvasive imaging methods to measure inflammation within the arterial wall. There is substantial evidence supporting the use of ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging for evaluation of atherosclerotic plaque inflammation. However, coronary imaging with this technique has been limited, due to several technical hurdles. Nonetheless, early experiences in coronary FDG-PET imaging have been encouraging. This review outlines the development of vascular PET imaging and its potential use for evaluation of coronary artery disease.     

正电子发射计算机断层技术在针刺临床中的应用进展

正电子发射计算机断层(PET)是当前核医学领域最先进的技术之一.本文综述了近几年PET技术在针刺临床治疗不同疾病中的应用进展.     

Risk Stratification with Cardiac Rubidium-82 Positron Emission Tomography

Positron emission tomography (PET) is an increasingly used imaging modality for stress myocardial perfusion imaging (MPI). Over the last several years, a rapidly increasing body of work supporting its use for estimation of extent and severity of coronary artery disease (CAD) and prognostication of risk of adverse cardiac events. In this review, we summarize these data, highlighting the strengths of PET MPI compared to single photon emission computed tomography (SPECT) with an emphasis on the differences in image acquisition, the ability to evaluate left ventricular systolic function during peak stress and the quantification of myocardial blood flow and coronary flow reserve.     

Clinical Utility of Positron Emission Tomography/Computed Tomography in Inflammatory Bowel Disease

Purpose  

The clinical utility of positron emission tomography/computed tomography (PET/CT) in comparison to standard workup in patients with known or suspected inflammatory bowel disease (IBD) is unknown.     

Neural Systems Shared by Visual Imagery and Visual Perception: A Positron Emission Tomography Study

Subjects participated in perceptual and imagery tasks while their brains were scanned using positron emission tomography. In the perceptual conditions, subjects judged whether names were appropriate for pictures. In one condition, the objects were pictured from canonical perspectives and could be recognized at first glance; in the other, the objects were pictured from noncanonical perspectives and were not immediately recognizable. In this second condition, we assume that top-down processing is used to evaluate the names. In the imagery conditions, subjects saw a grid with a single X mark; a lowercase letter was presented before the grid. In the baseline condition, they simply responded when they saw the stimulus, whereas in the imagery condition they visualized the corresponding block letter in the grid and decided whether it would have covered the X if it were physically present. Fourteen areas were activated in common by both tasks, only 1 of which may not be involved in visual processing (the precentral gyrus); in addition, 2 were activated in perception but not imagery, and 5 were activated in imagery but not perception. Thus, two-thirds of the activated areas were activated in common.     

Genome-free Viral Capsids as Carriers for Positron Emission Tomography Radiolabels

PURPOSE: We have developed a modular synthetic strategy to append imaging agents to a viral capsid. PROCEDURES: The hollow protein shell of bacteriophage MS2 (mtMS2) was labeled on its inside surface with [18F]fluorobenzaldehyde through a multistep bioconjugation strategy. An aldehyde functional group was first attached to interior tyrosine residues through a diazonium coupling reaction. The aldehyde was further elaborated to an alkoxyamine functional group, which was then condensed with n.c.a. [18F]fluorobenzaldehyde. Biodistribution of the radioactive MS2 conjugates was subsequently evaluated in Sprague-Dawley rats. RESULTS: Relative to fluorobenzaldehyde, fluorine-18-labeled MS2 exhibited prolonged blood circulation time and a significantly altered excretion profile. It was also observed that additional small molecule cargo installed inside the capsids did not alter the biodistribution. CONCLUSIONS: These studies provide further insight into the pharmacokinetic behavior of nanomaterials and serve as a platform for the future development of targeted imaging and therapeutic agents based on mtMS2.