Electron beam response corrections for an ultra-high-dose-rate capable diode dosimeter.

BACKGROUND: Ultra-high-dose-rate (UHDR) electron beams have been commonly utilized in FLASH studies and the translation of FLASH Radiotherapy (RT) to the clinic. The EDGE diode detector has potential use for UHDR dosimetry albeit with a beam energy dependency observed. PURPOSE: The purpose is to present the electron beam response for an EDGE detector in dependence on beam energy, to characterize the EDGE detector's response under UHDR conditions, and to validate correction factors derived from the first detailed Monte Carlo model of the EDGE diode against measurements, particularly under UHDR conditions. METHODS: Percentage depth doses (PDDs) for the UHDR Mobetron were measured with both EDGE detectors and films. A detailed Monte Carlo (MC) model of the EDGE detector has been configured according to the blueprint provided by the manufacturer under an NDA agreement. Water/silicon dose ratios of EDGE detector for a series of mono-energetic electron beams have been calculated. The dependence of the water/silicon dose ratio on depth for a FLASH relevant electron beam was also studied. An analytical approach for the correction of PDD measured with EDGE detectors was established. RESULTS: Water/silicon dose ratio decreased with decreasing electron beam energy. For the Mobetron 9 MeV UHDR electron beam, the ratio decreased from 1.09 to 1.03 in the build-up region, maintained in range of 0.98-1.02 at the fall-off region and raised to a plateau in value of 1.08 at the tail. By applying the corrections, good agreement between the PDDs measured by the EDGE detector and those measured with film was achieved. CONCLUSIONS: Electron beam response of an UHDR capable EDGE detector was derived from first principles utilizing a sophisticated MC model. An analytical approach was validated for the PDDs of UHDR electron beams. The results demonstrated the capability of EDGE detector in measuring PDDs of UHDR electron beams.

Self Harm and Suicidality: an audit of follow-up in primary care.

Deliberate self harm is the strongest predictor of completed suicide. Primary care is often the entry point for those presenting with self harm and suicidality and so the primary care follow-up of such patients should include risk assessment for repeated self harm and completed suicide. This is of particular importance in patients at high risk for suicide, such as those with Bipolar Affective Disorder. This audit makes recommendations for the average UK GP Teaching Practice based on standards from the NICE guidelines relating to the prevalence, timing and content of follow-up in primary care of those patients who present with self harm or suicidality in the practice population.

The Two Cultures: Where are we now?

In 1959 the physicist and novelist C. P. Snow described a schism in Western society. He said that the Sciences and the Arts were, in effect, 'two cultures'. How does that appraisal look to us now? This article looks at a development Snow cannot have anticipated - the current academic orthodoxy of 'Critical Theory', and an associated mistrust of scientific knowledge ….