149 research outputs found

    Definition of medical event is to be based on the total source strength for evaluation of permanent prostate brachytherapy: A report from the American Society for Radiation Oncology

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    AbstractPurposeThe Nuclear Regulatory Commission deems it to be a medical event (ME) if the total dose delivered differs from the prescribed dose by 20% or more. A dose-based definition of ME is not appropriate for permanent prostate brachytherapy as it generates too many spurious MEs and thereby creates unnecessary apprehension in patients, and ties up regulatory bodies and the licensees in unnecessary and burdensome investigations. A more suitable definition of ME is required for permanent prostate brachytherapy.Methods and MaterialsThe American Society for Radiation Oncology (ASTRO) formed a working group of experienced clinicians to review the literature, assess the validity of current regulations, and make specific recommendations about the definition of an ME in permanent prostate brachytherapy.ResultsThe working group found that the current definition of ME in §35.3045 as “the total dose delivered differs from the prescribed dose by 20 percent or more” was not suitable for permanent prostate brachytherapy since the prostate volume (and hence the resultant calculated prostate dose) is dependent on the timing of the imaging, the imaging modality used, the observer variability in prostate contouring, the planning margins used, inadequacies of brachytherapy treatment planning systems to calculate tissue doses, and seed migration within and outside the prostate. If a dose-based definition for permanent implants is applied strictly, many properly executed implants would be improperly classified as an ME leading to a detrimental effect on brachytherapy. The working group found that a source strength-based criterion, of >20% of source strength prescribed in the post-procedure written directive being implanted outside the planning target volume is more appropriate for defining ME in permanent prostate brachytherapy.ConclusionsASTRO recommends that the definition of ME for permanent prostate brachytherapy should not be dose based but should be based upon the source strength (air-kerma strength) administered

    Medical physics aspects of cancer care in the Asia Pacific region

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    Medical physics plays an essential role in modern medicine. This is particularly evident in cancer care where medical physicists are involved in radiotherapy treatment planning and quality assurance as well as in imaging and radiation protection. Due to the large variety of tasks and interests, medical physics is often subdivided into specialties such as radiology, nuclear medicine and radiation oncology medical physics. However, even within their specialty, the role of radiation oncology medical physicists (ROMPs) is diverse and varies between different societies. Therefore, a questionnaire was sent to leading medical physicists in most countries/areas in the Asia/Pacific region to determine the education, role and status of medical physicists

    Competition, prices and quality in the market for physician consultations

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    Prices for consultations with General Practitioners (GP's) in Australia are unregulated, and patients pay the difference between the price set by the GP and a fixed reimbursement from the national tax-funded Medicare insurance scheme. We construct a Vickrey-Salop model of GP price and quality competition and test its predictions using individual GP-level data on prices, the proportion of patients who are charged no out-of-pocket fee, average consultation length, and characteristics of the GP's, their practices and their local areas. We measure the competition to which the GP is exposed by the distance to other GP practices and allow for the endogeneity of GP location decisions with measures of area characteristics and area fixed-effects. Within areas, GP's with more distant competitors charge higher prices and a smaller proportion of their patients make no out-of-pocket payment. GP's with more distant competitors also have shorter consultations, though the effect is small and statistically insignificant
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