Journal of the ICRU最新文献

{"title":"International Commission on Radiation Units and Measurements","authors":"Hans-Georg Menzel","doi":"10.1093/jicru/ndx006","DOIUrl":"https://doi.org/10.1093/jicru/ndx006","url":null,"abstract":"The ICRU endeavors to collect and evaluate the latest data and information pertinent to the problems of radiation measurement and dosimetry and to recommend the most acceptable values and techniques for current use. The Commission’s recommendations are kept under continual review in order to keep abreast of the rapidly expanding uses of radiation. The ICRU feels that it is the responsibility of national organizations to introduce their own detailed technical procedures for the development and maintenance of standards. However, it urges that all countries adhere as closely as possible to the internationally recommended basic concepts of radiation quantities and units. The Commission feels that its responsibility lies in developing a system of quantities and units having the widest possible range of applicability. Situations can arise from time to time for which an expedient solution of a current problem might seem advisable. Generally speaking, however, the Commission feels that action based on expediency is inadvisable from a long-term viewpoint; it endeavors to base its decisions on the long-range advantages to be expected. The ICRU invites and welcomes constructive comments and suggestions regarding its recommendations and reports. These may be transmitted to the Chairman.","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"14 2","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/jicru/ndx006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68020522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"4. Treatment Planning Algorithms","authors":"","doi":"10.1093/jicru_ndx014","DOIUrl":"https://doi.org/10.1093/jicru_ndx014","url":null,"abstract":"An important limitation on the accuracy of the dose delivered to the patient in radiation therapy is determined by the accuracy of the treatment planning dose calculation algorithm. Existing recommendations for the commissioning and verification of treatment planning system (TPS) dose calculations are given by AAPM TG 53 (Fraass et al., 1998), IAEA TRS 430 (IAEA, 2004), NCS Report 15 (Reynaert et al., 2006). The American Association of Physicists in Medicine Task Group Report 67 described benchmark tests for the validation of dose calculation algorithms. These reports, however, are general and not sufficiently specific for small fields. This Section reviews some general features and addresses a few pertinent issues specific to dose calculation algorithms for small fields. An overview of historical and general aspects of treatment planning algorithms can be found in ICRU Report 83. This Section will concentrate on the details that should be considered when implementing these algorithms for small field stereotactic radiation therapy/stereotactic body radiotherapy (SRT/SBRT).","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"1 1","pages":"65 - 75"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90184108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Executive Summary","authors":"J. Stockdale","doi":"10.1093/jicru_ndx004","DOIUrl":"https://doi.org/10.1093/jicru_ndx004","url":null,"abstract":"In the context of this Report, stereotactic radiotherapy (SRT) encompasses stereotactic radiosurgery (SRS), stereotactic body radiation therapy (SBRT), and stereotactic ablative body radiation therapy (SABR). SRT involves stereotactic localization techniques (i.e., use of a three-dimensional coordinate system to localize the target) combined with the delivery of multiple small photon fields in a few high-dose fractions. There is wide diversity in the clinical prescriptions for SRS and SBRT, some of which are based on preclinical studies, some based on modeling using the linear-quadratic (LQ) model, and others that result from trial-and-error experiences. The limitations of the LQmodel in scenarios of SRS/SBRTmight suggest the possible existence of new cell-death mechanisms related to stem cells, vascular damage, bystander effects, and immune-mediated effects, or combinations of these. Therefore, there is a need to develop a better rationale for current practice and future hypofractionation clinical trials by incorporating classical and new radiobiology and appropriately upgrading the modeling schemes for high doses to reflect new evidence-based understanding of tumor control and normal-tissue tolerances at higher doses per fraction. The understanding of the radiobiology of hypofractionation has been the subject of renewed intense interest driven by clinical successes and socio-economical benefits of shortened treatment times and potentially improved outcomes. The role of clinical medical physics in radiation therapy is to ensure that the prescription is delivered accurately. Comprehensive quality assurance encompasses all aspects of radiation medicine ranging from SRT device acceptance, commissioning, image guidance, and delivery. Recent incidents in radiation therapy using small fields have indicated that the dosimetry of small fields is complex and prone to errors. The requirements in terms of accurate beam calibration, treatment planning, accuracy of delivery, and quality assurance are more stringent than in other areas of radiation therapy. The active collaboration among all professions in the SRT program is critical for treatment quality and patient safety. Three main features dominate the dosimetry of small beams from accelerators. Firstly, absorbeddose distributions formed by small beams are characterized by a lack of charged-particle equilibrium over a much greater fraction of the treatment volume than for conventional radiotherapies. This has implications in dose measurements as well as treatment-planning dose calculations, especially in the vicinity of tissue heterogeneities. Secondly, in small beams, part of the source is often occluded by the collimation system, leading to beam-penumbra overlap and a drastic reduction in output fluence rate. Overlap of penumbra leads to effective-beam broadening in small beams compared to the geometric beam definition. Thirdly, the measurement of absorbed dose from small beams is highly dependent on t","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"42 1","pages":"7 - 9"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72781550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"7. Prescribing, Recording, and Reporting","authors":"","doi":"10.1093/jicru/ndx010","DOIUrl":"https://doi.org/10.1093/jicru/ndx010","url":null,"abstract":"","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"14 2","pages":"101-109"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/jicru/ndx010","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68020520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"2. Small Field Dosimetry","authors":"Field Dosimetry","doi":"10.1093/jicru_ndx012","DOIUrl":"https://doi.org/10.1093/jicru_ndx012","url":null,"abstract":"The role of clinical medical physics in radiation therapy is to ensure that the prescription is delivered accurately. This means that there is a need for a comprehensive quality assurance program, which encompasses all aspects of radiation medicine ranging from therapy machine acceptance, commissioning and calibration, image guidance and delivery, and that all procedures and workflows are in place to deliver the prescription accurately. The dosimetric portion of the quality assurance program starts with accurate calibration of the beam and the measurement of output factors and other dosimetric functions. In this context, the requirements in terms of accurate beam calibration, treatment planning, delivery, and quality assurance of stereotactic radiation therapy are as stringent, if not more stringent, as in conventional radiation therapy (Thwaites, 2013). Recent incidents in radiation therapy (Ford and Evans, 2014; IAEA, 2014) using small fields have indicated that dosimetry of small fields is complex and prone to errors. In general, absorbed dose determination in small fields requires multiple levels of redundancy including the use of different detectors with appropriate detector-dependent correction factors for the measurements, a critical analysis of measured data on equipment of the same type in comparison with peer centers, corroboration of data with manufacturer “golden beam data” (i.e., reference data), etc. As will be clear from the present section, simple pooling of relative reading data from different detector types is not the same as the relative dose in small fields; accurate depth and field-size dependent correction factors are required to ensure that the detector signal is faithfully converted into absorbed dose. In addition, the execution of an independent third-party dosimetry end-to-end review (e.g., Imaging and Radiation Oncology Core, IROC, MD Anderson Houston) is strongly suggested. Because of this complexity, an institution starting a new small-field radiation therapy program should consider training programs for physicists, radiation therapy planning personnel and radiation oncologists that includes a review of the basis of small field dosimetry. The active collaboration between all professions in the SRT program is critical for treatment quality and patient safety. In 3D conformal radiation therapy, higher energies (defined for the purpose of this discussion as photon beams created from accelerating potentials of larger than 10MV) are regularly used to improve coverage in the case of deep-seated tumors. The secondary electron path for a 15MV beam may be of the order of 3 cm or more thereby significantly affecting penumbra width. This leads to problems in the application of SRT using higher energies especially for small targets in regions involving lower density, such as lung. In these conditions, the accuracy requirements imposed on the dose calculation algorithm used for treatment planning are more difficult to meet for hig","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"108 1","pages":"31 - 53"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91339427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Appendix A: Clinical Examples","authors":"","doi":"10.1093/jicru_ndx002","DOIUrl":"https://doi.org/10.1093/jicru_ndx002","url":null,"abstract":"A 79 year old male presented with increased shortness of breath and mass on a chest xray in February 2015. The mass was located in the left middle lobe and had a diameter of 12mm on a CTscan. Bronchoscopy revealed a squamous cell carcinoma and the PET(CT) scan showed a solitary PET-positive nodule in the lung. The patient had a history of COPD GOLD class III with a FEV1 (forced expiratory volume) of 1130ml (46 % of the predicted value) and a history of cerebrovascular accidents and transient ischemic attack. The ventilation/perfusion scan showed that the right lung contributed 48 % of the ventilation/perfusion capacity while the left lung contributed 42 %. As the patient had mediocre lung function, he was considered inoperable. This patient was referred for curative stereotactic treatment with the CyberKnife.","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"1 1","pages":"111 - 122"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76154745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"1. Introduction","authors":"","doi":"10.1093/jicru/ndx008","DOIUrl":"https://doi.org/10.1093/jicru/ndx008","url":null,"abstract":"","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"14 2","pages":"11-30"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/jicru/ndx008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68020527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"2. Small Field Dosimetry","authors":"","doi":"10.1093/jicru/ndx012","DOIUrl":"https://doi.org/10.1093/jicru/ndx012","url":null,"abstract":"","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"14 2","pages":"31-53"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/jicru/ndx012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68020524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"6. Quality Assurance","authors":"","doi":"10.1093/jicru_ndx011","DOIUrl":"https://doi.org/10.1093/jicru_ndx011","url":null,"abstract":"A comprehensive quality assurance (QA) program should aim to ensure the safest and highest achievable accuracy of radiation treatment by establishing a systematic approach in setting up and in maintaining the program. The goal of QA is to reduce the uncertainty in SRT treatment and to set an error tolerance limit for SRT treatment. The overall uncertainty of an SRT system is the combination of uncertainties resulting from several components, which mainly consist of uncertainties in the:","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"1 1","pages":"93 - 99"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75341653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"5. Image-Guided Beam Delivery","authors":"","doi":"10.1093/jicru/ndx007","DOIUrl":"https://doi.org/10.1093/jicru/ndx007","url":null,"abstract":"","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"14 2","pages":"77-92"},"PeriodicalIF":0.0,"publicationDate":"2014-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/jicru/ndx007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68020517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}