No abstract

Purpose To determine whether [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) can delineate patients with esophageal cancer who may not benefit from esophagectomy after chemoradiotherapy. Patients and Methods We reviewed records of 163 patients with histologically confirmed stage I to IVA esophageal cancer receiving chemoradiotherapy with or without resection with curative intent. All patients received surgical evaluation. Initial and postchemoradiotherapy FDG-PET scans and prognostic/treatment variables were analyzed. FDG-PET complete response (PET-CR) after chemoradiotherapy was defined as standardized uptake value ≤ 3. Results Eighty-eight patients received trimodality therapy and 75 received chemoradiotherapy. Surgery was deferred primarily due to medical inoperability or unresectable/metastatic disease after chemoradiotherapy. A total of 105 patients were evaluable for postchemoradiotherapy FDG-PET response. Thirty-one percent achieved a PET-CR. PET-CR predicted for improved outcomes for chemoradiotherapy (2-year overall survival, 71% v 11%, P < .01; 2-year freedom from local failure [LFF], 75% v 28%, P < .01), but not trimodality therapy. On multivariate analysis of patients treated with chemoradiotherapy, PET-CR is the strongest independent prognostic variable (survival hazard ratio [HR], 9.82, P < .01; LFF HR, 14.13, P < .01). PET-CR predicted for improved outcomes regardless of histology, although patients with adenocarcinoma achieved a PET-CR less often. Conclusion Patients treated with trimodality therapy found no benefit with PET-CR, likely because FDG-PET residual disease was resected. Definitive chemoradiotherapy patients achieving PET-CR had excellent outcomes equivalent to trimodality therapy despite poorer baseline characteristics. Patients who achieve a PET-CR may not benefit from added resection given their excellent outcomes without resection. These results should be validated in a prospective trial of FDG-PET–directed therapy for esophageal cancer.

Background: Evaluation of newly diagnosed patients with melanoma for metastasis is requisite to treatment planning. The reported diagnostic yield of whole-body conventional radiological imaging in initial staging of patients with melanoma is low. However, the diagnostic yield of positron emission tomography (PET) for distant metastases is unclear. Hypothesis: There is no utility of PET as part of a routine metastatic survey in patients with T2 to T4 melanoma.

Long-term survival is possible with parathyroid carcinoma. Death associated with parathyroid carcinoma was uncommon. A staging may be warranted despite the rarity of this disease.

FDG uptake in HBAT has been noted to occur more frequently in cold months and benzodiazepines have been proposed for its prevention. The use of these drugs is, in our experience, of limited value and may complicate patient care in both inpatient and outpatient populations. In this report, we describe considerable success by completely reversing HBAT in 9 of 10 sequential patients with simple core warming maneuvers, which obviate the use of benzodiazepines.

Objectives To assess the utility of dobutamine cardiovascular magnetic resonance (DCMR) results for predicting cardiac events in individuals with reduced left ventricular ejection fraction (LVEF). Background It is unknown whether DCMR results identify a poor cardiac prognosis when the resting LVEF is moderately to severely reduced. Methods Two-hundred consecutive patients aged 30 to 88 (average 64) years with a LVEF ≤55% that were poorly suited for stress echocardiography, underwent DCMR in which LV wall motion score index (WMSI), defined as the average wall motion of the number of segments scored, was assessed at rest, during low dose, and after peak intravenous infusion of dobutamine/atropine. All participants were followed for an average of 5 years after DCMR to ascertain the post testing occurrence of cardiac death, myocardial infarction (MI), and unstable angina or congestive heart failure warranting hospitalization. Results After accounting for risk factors associated with coronary arteriosclerosis and MI, a stress induced increase in WMSI during DCMR was associated with future cardiac events (p< 0.001). After accounting for resting LVEF, a DCMR stress induced change in WMSI added significantly to predicting future cardiac events (p=0.003), but this predictive value was confined primarily to those with a LVEF >40%. Conclusions In individuals with mild to moderate reductions in LVEF (40% to 55%), dobutamine induced increases in WMSI forecast MI and cardiac death to a greater extent than an assessment of resting LVEF. In those with a LVEF < 40%, a dobutamine induced increase in WMSI does not predict MI and cardiac death beyond the assessment of resting LVEF.

OBJECTIVEβ-Cell turnover and its potential to permit β-cell regeneration in adult primates are unknown. Our aims were 1) to measure β-cell turnover in adult nonhuman primates; 2) to establish the relative contribution of β-cell replication and formation of new β-cells from other precursors (defined thus as β-cell neogenesis); and 3) to establish whether there is an adaptive increase in β-cell formation (attempted regeneration) in streptozotocin (STZ)-induced diabetes in adult nonhuman primates.RESEARCH DESIGN AND METHODSAdult (aged 7 years) vervet monkeys were administered STZ (45–55 mg/kg, n = 7) or saline (n = 9). Pancreas was obtained from each animal twice, first by open surgical biopsy and then by euthanasia. β-Cell turnover was evaluated by applying a mathematic model to measured replication and apoptosis rates.RESULTSβ-Cell turnover is present in adult nonhuman primates (3.3 ± 0.9 mg/month), mostly (∼80%) derived from β-cell neogenesis. β-Cell formation was minimal in STZ-induced diabetes. Despite marked hyperglycemia, β-cell apoptosis was not increased in monkeys administered STZ.CONCLUSIONSThere is ongoing β-cell turnover in adult nonhuman primates that cannot be accounted for by β-cell replication. There is no evidence of β-cell regeneration in monkeys administered STZ. Hyperglycemia does not induce β-cell apoptosis in nonhuman primates in vivo.

The pancreas is one of the most heavily innervated peripheral organs in the body. Parasympathetic and sympathetic neurons terminate in the pancreas and provide tight control of endocrine and exocrine functions. The aim of this study was to determine whether the pancreas can be imaged with a radioligand that binds to specific neuroreceptors. Using fluorine-18 4-fluorobenzyltrozamicol (FBT), which binds to the presynaptic vesicular acetylcholine transporter, positron emission tomography scans were performed in four adult mice, two adult rhesus monkeys, and one adult human. In these mammals, the pancreas is intensely FBT avid, with uptake greater than in any other organ at 30, 60, and 90 min. The maximum standardized uptake value (SUV) ratios of pancreas to liver, for example, ranged from 1.4 to 1.7 in rhesus monkeys (mean 1.6; median 1.7) and from 1.9 to 4.7 (mean 3.24; median 3.02) in mice. The maximum SUV ratio of pancreas to liver in the human was 1.8. These data suggest that neuroreceptor imaging of the pancreas in vivo is feasible in animal models and humans. This imaging could allow researchers to interrogate functions under control of the autonomic nervous system in the pancreas, with applications possible in transplanted and native pancreata. Also, as beta cell function is intimately related to parasympathetic cholinergic input, FBT activity in the pancreas may correlate with insulin-producing beta cell mass. This could ultimately provide a method of in vivo imaging in animal models and humans for diabetes research.