We proposed that metabolic remodeling in the form of increased myocardial glucose analogue 2-[18F] fluoro-2deoxy-D-glucose (FDG) uptake precedes and triggers the onset of severe contractile dysfunction in pressure overload left ventricular hypertrophy (LVH) in vivo. To test this hypothesis we used a mouse model of transverse aortic constriction (TAC) together with Positron Emission Tomography (PET) and assessed serial changes in cardiac metabolism and function over 7 days. Methods PET scans of 16 C57BL/6 male mice were performed using a microPET scanner under sevofluorane anesthesia. A 10-minute transmission scan was followed by a 60-minute dynamic FDG-PET scan with cardiac and respiratory gating. Blood glucose levels were measured before and after the emission scan. Transverse aortic constriction (TAC) and sham surgeries were performed after baseline imaging. Osmotic mini-pumps containing either propranolol (5 mg/kg/day) or vehicle alone were implanted subcutaneously at the end of surgery. Subsequent scans were taken at days 1 and 7 after surgery. A compartment model, in which the blood input function with spill-over and partial volume corrections and the metabolic rate constants in a 3-compartment model are simultaneously estimated, was used to determine the net myocardial FDG influx constant, Ki. The rate of myocardial glucose use, rMGU, was also computed. Estimations of the ejection fractions (EF) were based on the high resolution gated PET images Results Mice undergoing TAC surgery exhibited an increase in the Ki (580%) and glucose usage the day after surgery indicating early adaptive response. On day 7 the EF had decreased by 24% indicating a maladaptive response. Average Ki increases were not linearly associated with increases in rMGU. Ki exceeded rMGU by 29% in the TAC mice. TAC Mice treated with propranolol attenuated rate of FDG uptake, diminished mismatch between Ki and rMGU (9%) and rescued cardiac function. Conclusions Metabolic maladaptation precedes the onset of severe contractile dysfunction. Both are prevented by treatment with propranolol. Early detection of metabolic remodeling may offer a metabolic target for modulation of hypertrophy.
The QA tool assists users to detect potential delineation errors. QA tool integration into clinical procedures may reduce the frequency of inaccurate OAR delineation, and potentially improve safety and quality of radiation treatment planning.
Patients with intermediate to high risk disease (prostate specific antigen (PSA) ≥ 10, Gleason score ≥ 7, or clinical stage ≥ T2b) suffer from poorer long-term biochemical control (freedom from an increasing prostate specific antigen level) when treated with external beam radiation (EBRT) alone. In order to improve biochemical control while limiting long-term complications, brachytherapy has been incorporated into radiotherapy treatment, either alone or in combination with EBRT. Areas covered: Current literature regarding the use of high dose-rate (HDR) brachytherapy for localized prostate cancer, including as a boost and monotherapy. The efficacy and toxicities of various approaches are evaluated including comparisons to low dose-rate (LDR) brachytherapy. Expert commentary: Prostate HDR brachytherapy has higher conformality than EBRT, potentially improving the therapeutic ratio by allowing higher doses per fraction to tumor cells. The improved biochemical control shown in trials have resulted in EBRT plus brachytherapy to be included as a standard treatment option supported by the NCCN and ASCO guidance documents for intermediate to high risk prostate cancer.
Hemangiopericytomas are rare central nervous system (CNS) tumors. We sought to investigate existing clinical management strategies and overall survival (OS) among patients with hemangiopericytomas arising from the CNS. Materials/Methods: All patients diagnosed with CNS hemangiopericytoma from 2004-2014 in the National Cancer Database were included. Clinical and treatment-related characteristics were recorded and analyzed for an association with OS following diagnosis using univariable and multivariable analyses. Results: Nine-hundred and eighty-one patients were included (0.22% of all CNS tumors). At diagnosis, 22 patients had spinal tumors (2%), 21 patients had multifocal tumors (2%) and 28 had disseminated disease (3%). Patients either underwent surgical resection and radiation (48%), surgery alone (37%), radiation alone (6%), or biopsy alone (9%). Of patients with known extent of resection, 53% underwent gross total resection, and, of patients with known radiation modality, 15% received stereotactic radiosurgery. Among the total cohort, 3 and 10 year OS was 87% and 59%, respectively. On multivariable analysis, factors associated with inferior OS included age (HRZ1.05, p<0.001), WHO grade (p<0.001), multifocal disease (HRZ2.59, pZ0.04), disseminated disease (HRZ2.67, pZ0.01), and chemotherapy (HRZ2.66, pZ0.01). Patients receiving surgery alone or surgery and radiation demonstrated improved OS compared to biopsy alone (HRZ0.45, pZ0.01 and HRZ0.47, pZ0.02, respectively). However radiation utilization did not impact OS (pZ0.691). Conclusion: The present data provide large-scale prognostic information from a contemporary cohort of patients with hemangiopericytoma and support an initial attempt at surgical extirpation. The benefits of ionizing radiation are likely limited to improved local control and neurologic function.
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