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

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

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Not AvailableA study was conducted at IGFRI, Jhansi to evaluate the soil quality through analysis of alkaline monophosphatase activity as affected by pre-emergence application of atrazine @ 1.5 kg a.i. ha-1 and supplementation with farmyard manure in fodder sorghum (cv PC-6) during two consecutive kharif seasons. It was observed that atrazine had some inhibitory effect on soil enzyme activity during initial phases of crop growth, but the effect was not much pronounced and the activity was restored to a considerable extent. Introduction of FYM showed positive effect on soil quality and correlation of organic matter with enzyme activity in sub-surface soil samples. No phytotoxicity was observed in the crop at the used rate of atrazine application.ICA

Waste to wealth?a green initiative by ICAR-CIFRI

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Waste to wealth?a green initiative by ICAR-CIFRI

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Anti-microbial compounds Triclosan and Triclocarban in a Himalayan River

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