New Digital Plug and Imaging Sensor for a Proton Therapy Monitoring System Based on Positron Emission Tomography.

One of the most challenging areas of sensor development for nuclear medicine is the design of proton therapy monitoring systems. Sensors are operated in a high detection rate regime in beam-on conditions. We realized a prototype of a monitoring system for proton therapy based on the technique of positron emission tomography. We used the Plug and Imaging (P&I) technology in this application. This sensing system includes LYSO/silicon photomultiplier (SiPM) detection elements, fast digital multi voltage threshold (MVT) readout electronics and dedicated image reconstruction algorithms. In this paper, we show that the P&I sensor system has a uniform response and is controllable in the experimental conditions of the proton therapy room. The prototype of PET monitoring device based on the P&I sensor system has an intrinsic experimental spatial resolution of approximately 3 mm (FWHM), obtained operating the prototype both during the beam irradiation and right after it. The count-rate performance of the P&I sensor approaches 5 Mcps and allows the collection of relevant statistics for the nuclide analysis. The measurement of both the half life and the relative abundance of the positron emitters generated in the target volume through irradiation of 10 10 protons in approximately 15 s is performed with 0.5% and 5 % accuracy, respectively.

Prostate-selective α antagonists increase fracture risk in prostate cancer patients with and without a history of androgen deprivation therapy: a nationwide population-based study.

INTRODUCTIONS: Prostate-selective α antagonists are recommended for relief of lower urinary tract symptoms in prostate cancer patients despite uncertainty of fracture risk as an addition to androgen deprivation therapy (ADT). The purpose of this study is to estimate fracture risk associated with these medications in prostate cancer patients who did and did not receive ADT. METHODS: The Taiwan National Health Insurance database was used to identify prostate cancer patients. We identified all 90-day person-quarters exposed to and not exposed to prostate-selective α antagonists. A generalized estimating equation model was used to estimated adjusted odd ratios (ORs) and 95% confidence intervals (CIs) for fracture associated with prostate-selective α antagonists with consideration for confounding by indication bias using propensity score. RESULTS: During 1997-2008, 16,601 persons received a diagnosis of prostate cancer, among whom 13,694 received ADT. Among prostate cancer patients receiving ADT, fracture was significantly more common in person-quarters with prostate-selective α antagonist use than in quarters without such treatment (OR, 1.08; 95% CI, 1.00-1.18). Prostate-selective α antagonist use was most strongly associated with femur fracture (OR, 1.22; 95% CI, 1.09-1.38), followed by skull fracture (OR, 1.29; 95% CIs: 0.93-1.80). Among patients who did not receive ADT, fracture was more common in person-quarters with prostate-selective α antagonist use than in those without medication use (OR, 1.19; 95% CI, 0.91-1.55). CONCLUSIONS: Prostate-selective α antagonist is associated with an increased fracture risk, particular for fractures in skull and femur. Patients should be well-informed on this potential risk before taking prostate-selective α antagonists.