Pub Date : 2019-12-01DOI: 10.1177/1473669119893182
In this section, we discuss assessment techniques for individuals who may have been exposed to neutrons or to radioactive materials, leading to contamination of the body externally and/or internally. In the case of bodily contamination, exposure implies more than simply receiving a radiation dose from an external source. It also includes those conditions leading to persons becoming contaminated with radioactive materials and/or debris. Contamination of the external surface of the body is likely to be very heterogeneous in most circumstances. The degree of contamination will depend on the situation in which contact with radioactive contamination took place and also on the physical attributes of that part of the body that is contaminated, attributes of clothing worn at the time of contamination, whether internal contamination took place, and the chemical or physical form of the contaminants. Contaminated debris can manifest itself in many forms, although particulates are likely to be the most common physical form for many accidents or intentional exposure situations. Knowledge of the form of the contamination is usually helpful in deciding the best type of assay and instrumentation to be used. Unlike the situation of body contamination, dose distribution within the body when exposure to neutrons occurs is always highly heterogeneous, even for a whole-body irradiation. This is due to the high values of the cross sections for neutron interaction with the light atoms composing living tissue, especially hydrogen and nitrogen. In the energy range of fission neutrons (0.0025 eV to 12 MeV), which may be encountered in a criticality accident, for example, most of the dose would be deposited close to that portion of the body surface where neutrons are incident. This section briefly discusses methods and issues related to assessing contamination and/or internal deposition in the body, as well as some dosimetry techniques that are of interest in these situations. References provided give information on converting the results of contamination assays to absorbed dose. We also discuss dosimetry due to neutron exposure using the method of neutron activation.
{"title":"6 Other Individual-Person Radiation Dose Assessments","authors":"","doi":"10.1177/1473669119893182","DOIUrl":"https://doi.org/10.1177/1473669119893182","url":null,"abstract":"In this section, we discuss assessment techniques for individuals who may have been exposed to neutrons or to radioactive materials, leading to contamination of the body externally and/or internally. In the case of bodily contamination, exposure implies more than simply receiving a radiation dose from an external source. It also includes those conditions leading to persons becoming contaminated with radioactive materials and/or debris. Contamination of the external surface of the body is likely to be very heterogeneous in most circumstances. The degree of contamination will depend on the situation in which contact with radioactive contamination took place and also on the physical attributes of that part of the body that is contaminated, attributes of clothing worn at the time of contamination, whether internal contamination took place, and the chemical or physical form of the contaminants. Contaminated debris can manifest itself in many forms, although particulates are likely to be the most common physical form for many accidents or intentional exposure situations. Knowledge of the form of the contamination is usually helpful in deciding the best type of assay and instrumentation to be used. Unlike the situation of body contamination, dose distribution within the body when exposure to neutrons occurs is always highly heterogeneous, even for a whole-body irradiation. This is due to the high values of the cross sections for neutron interaction with the light atoms composing living tissue, especially hydrogen and nitrogen. In the energy range of fission neutrons (0.0025 eV to 12 MeV), which may be encountered in a criticality accident, for example, most of the dose would be deposited close to that portion of the body surface where neutrons are incident. This section briefly discusses methods and issues related to assessing contamination and/or internal deposition in the body, as well as some dosimetry techniques that are of interest in these situations. References provided give information on converting the results of contamination assays to absorbed dose. We also discuss dosimetry due to neutron exposure using the method of neutron activation.","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"41 1","pages":"88 - 98"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81315043","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}
Pub Date : 2019-12-01DOI: 10.1177/1473669119893146
A quantity closely related to absorbed dose is kerma (kinetic energy released per unit mass), which is the total kinetic energy released by all charged particles in a volume of specific mass. The units are also J·kg, with the name Gray (Gy). It is a useful quantity when assessing the absorbed dose in air at a location where individuals may have been located when the absorbed dose to those individuals is not available or cannot be obtained. It is the unit that is relevant when electronic equilibrium cannot be assumed and is often used for calibration in reference photon radiation fields. 2.1.3 RBE–Weighted Absorbed Dose
{"title":"2 Quantities","authors":"","doi":"10.1177/1473669119893146","DOIUrl":"https://doi.org/10.1177/1473669119893146","url":null,"abstract":"A quantity closely related to absorbed dose is kerma (kinetic energy released per unit mass), which is the total kinetic energy released by all charged particles in a volume of specific mass. The units are also J·kg, with the name Gray (Gy). It is a useful quantity when assessing the absorbed dose in air at a location where individuals may have been located when the absorbed dose to those individuals is not available or cannot be obtained. It is the unit that is relevant when electronic equilibrium cannot be assumed and is often used for calibration in reference photon radiation fields. 2.1.3 RBE–Weighted Absorbed Dose","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"105 1","pages":"18 - 25"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75691871","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}
Pub Date : 2019-07-06DOI: 10.1177/1473669119893130
Oleg Ustenko, Julia Segura, Valentyn Povroznyuk, Edilberto L. Segura
Russian-backed separatists have intensified their military attacks against the Ukrainian army and the border territories controlled by the central government. The intensity of daily artillery shootings is high at about 10 to 20 per day. More than 400 Ukrainian civilians and militants were killed in 2017. Ukrainian international allies continue their support to the country. The most recent decision of the US to supply Ukraine with the lethal weapon equipment should increase the country’s defensive capacity.
{"title":"Executive Summary","authors":"Oleg Ustenko, Julia Segura, Valentyn Povroznyuk, Edilberto L. Segura","doi":"10.1177/1473669119893130","DOIUrl":"https://doi.org/10.1177/1473669119893130","url":null,"abstract":" Russian-backed separatists have intensified their military attacks against the Ukrainian army and the border territories controlled by the central government. The intensity of daily artillery shootings is high at about 10 to 20 per day. More than 400 Ukrainian civilians and militants were killed in 2017. Ukrainian international allies continue their support to the country. The most recent decision of the US to supply Ukraine with the lethal weapon equipment should increase the country’s defensive capacity.","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"40 3","pages":"12 - 12"},"PeriodicalIF":0.0,"publicationDate":"2019-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1473669119893130","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72429961","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}
With the exception of the first ion beam treatments using deuterium and helium beams in 1954 at Berkeley, which were cyclotron-based, only synchrotron-based therapy facilities are in operation today for carbon or other light ion beam therapy. This is due to the significantly higher energies needed to achieve the same range as a proton beam. After the early studies at the Lawrence Berkeley National Laboratory (LBNL) (Castro, 1993), all dedicated particle therapy facilities concentrated primarily on carbon beams for radiotherapy. The layout of a modern synchrotron for carbon ions is also suited to accelerate protons and many therapy facilities do offer proton beams for therapy in addition to carbon ions, which facilitates comparative clinical trials between modalities. Although technically feasible, only the Heidelberg ion beam facility (Haberer et al., 2004) is offering the possibility of providing helium and oxygen ions in addition to protons and carbon ions in all treatment rooms for potential future clinical use. The magnet strength and the fixed diameter of the accelerator ring limit the maximum achievable energy for each ion. A typical synchrotron-based ion facility comprises the following main components: (i) one or several ion sources; (ii) a linac, which acts as a pre-accelerator; (iii) the main synchrotron accelerator to produce high-energy ions; (iv) a beam-transport system to steer the beam to the treatment-delivery system; (v) a treatment-delivery system to adapt the individual treatment fields for each patient. Ion sources use an ionized gas to produce the ions, so that only specific ions can be extracted, using a spectrometer, to select a well-defined charge to mass ratio. The ionized gas is confined by magnetic fields and heated by microwaves, so that a plasma is created. Therefore, separate ion sources are in use for protons, carbon and helium ions, while an oxygen beam can be extracted from the same source as carbon (using carbon dioxide). The beam from different ion sources can be switched quickly to the injection beam line, using a switching magnet. The extraction of a different ion from the same source takes time to tune the source. The ion source is also used to control the beam intensity. The linac injector accelerates ions from several keV/u to the injection energy of the synchrotron, which is typically around 5MeV/u to 10MeV/u. In the main ring, bunches of ions are being injected, accelerated step by step to the desired energy and then extracted to the high-energy beam transport system. This means that the extracted energy can be adapted according to the energy requested by a treatment plan. During acceleration, the magnetic field strength in the ring magnets has to be gradually increased, as well as the frequency of the accelerating radio frequency (RF) cavity. The setting of all the beam elements from the ion source to the high-energy beam line is controlled by an accelerator control system (ACS). The ACS usually can prov
除了1954年在伯克利使用氘和氦束进行的第一次离子束治疗，这是基于回旋加速器的，今天只有基于同步加速器的治疗设施在运行，用于碳或其他光离子束治疗。这是由于要达到与质子束相同的距离需要更高的能量。在劳伦斯伯克利国家实验室(LBNL) (Castro, 1993)的早期研究之后，所有专门的粒子治疗设施主要集中在碳束放射治疗上。现代碳离子同步加速器的布局也适合于加速质子，许多治疗设施除了提供碳离子治疗外，还提供质子束，这有助于不同模式之间的比较临床试验。虽然技术上可行，但只有海德堡离子束设施(Haberer et al.， 2004)提供了在所有治疗室提供质子和碳离子之外的氦和氧离子的可能性，以供未来潜在的临床使用。磁铁的强度和加速器环的固定直径限制了每个离子可达到的最大能量。一个典型的基于同步加速器的离子设施包括以下主要组成部分:(i)一个或几个离子源;(ii)作为预加速器的直线加速器;(三)主同步加速器产生高能离子;(iv)光束传输系统，将光束引导至治疗输送系统;(v)为每个病人调整个别治疗领域的治疗递送系统。离子源使用电离气体来产生离子，因此只有特定的离子才能被提取出来，使用光谱仪来选择一个明确的电荷质量比。电离后的气体受到磁场的限制，并被微波加热，这样就产生了等离子体。因此，质子、碳离子和氦离子使用不同的离子源，而氧束可以从与碳相同的来源(使用二氧化碳)中提取。来自不同离子源的光束可以使用开关磁铁快速切换到注入束流线上。从同一源提取不同的离子需要时间来调整源。离子源也用于控制光束强度。直线注入器将数keV/u的离子加速到同步加速器的注入能量，通常在5MeV/u至10MeV/u左右。在主环中，离子束被注入，逐步加速到所需的能量，然后被提取到高能束流传输系统。这意味着提取的能量可以根据治疗计划所需的能量进行调整。在加速过程中，环形磁体中的磁场强度必须逐渐增加，加速射频(RF)腔的频率也必须逐渐增加。从离子源到高能束流线的所有束流元素的设置由加速器控制系统(ACS)控制。ACS通常可以提供预先设定的离子类型、能量、束流直径和束流强度。在光束输送系统(BDS)中，对小聚焦单能量光束进行修饰，从而形成有用的治疗场。此外，它正在监测输送的光束，并控制输送给患者的rbe加权剂量。北斗系统可以采用被动或动态技术，由处理控制系统(TCS)控制，该系统也可以控制ACS。TCS还作为治疗计划系统的接口。考虑到病人的安全，TCS是医院中最重要的系统。北斗系统还可能包括以下部分或全部子系统:喷嘴、监测系统、波束扫描仪、门控装置、患者定位和固定系统。实际上，在水中穿透25厘米需要400MeV/u的碳能量(即总动能为4.8 GeV) (Chu et al.， 1993)。与质子治疗束相比，提取的离子能量更高，导致束的磁刚性增加(Trbojevic等人，2007)。这是由具有更高磁场和更大弯曲半径的弯曲磁铁补偿的。此外，减少的横向散射和增加的高能离子的磁刚性导致了非常长的BDS，通常为6米至10米
{"title":"3. Beam Delivery and Properties","authors":"","doi":"10.1093/jicru_ndy026","DOIUrl":"https://doi.org/10.1093/jicru_ndy026","url":null,"abstract":"With the exception of the first ion beam treatments using deuterium and helium beams in 1954 at Berkeley, which were cyclotron-based, only synchrotron-based therapy facilities are in operation today for carbon or other light ion beam therapy. This is due to the significantly higher energies needed to achieve the same range as a proton beam. After the early studies at the Lawrence Berkeley National Laboratory (LBNL) (Castro, 1993), all dedicated particle therapy facilities concentrated primarily on carbon beams for radiotherapy. The layout of a modern synchrotron for carbon ions is also suited to accelerate protons and many therapy facilities do offer proton beams for therapy in addition to carbon ions, which facilitates comparative clinical trials between modalities. Although technically feasible, only the Heidelberg ion beam facility (Haberer et al., 2004) is offering the possibility of providing helium and oxygen ions in addition to protons and carbon ions in all treatment rooms for potential future clinical use. The magnet strength and the fixed diameter of the accelerator ring limit the maximum achievable energy for each ion. A typical synchrotron-based ion facility comprises the following main components: (i) one or several ion sources; (ii) a linac, which acts as a pre-accelerator; (iii) the main synchrotron accelerator to produce high-energy ions; (iv) a beam-transport system to steer the beam to the treatment-delivery system; (v) a treatment-delivery system to adapt the individual treatment fields for each patient. Ion sources use an ionized gas to produce the ions, so that only specific ions can be extracted, using a spectrometer, to select a well-defined charge to mass ratio. The ionized gas is confined by magnetic fields and heated by microwaves, so that a plasma is created. Therefore, separate ion sources are in use for protons, carbon and helium ions, while an oxygen beam can be extracted from the same source as carbon (using carbon dioxide). The beam from different ion sources can be switched quickly to the injection beam line, using a switching magnet. The extraction of a different ion from the same source takes time to tune the source. The ion source is also used to control the beam intensity. The linac injector accelerates ions from several keV/u to the injection energy of the synchrotron, which is typically around 5MeV/u to 10MeV/u. In the main ring, bunches of ions are being injected, accelerated step by step to the desired energy and then extracted to the high-energy beam transport system. This means that the extracted energy can be adapted according to the energy requested by a treatment plan. During acceleration, the magnetic field strength in the ring magnets has to be gradually increased, as well as the frequency of the accelerating radio frequency (RF) cavity. The setting of all the beam elements from the ion source to the high-energy beam line is controlled by an accelerator control system (ACS). The ACS usually can prov","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"67 1","pages":"37 - 58"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78094639","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}
A 38-year-old woman with a history of double vision due to the paresis of the left N. abducens: a biopsy was performed to confirm the diagnosis of clivus chordoma. Staging with MRI of the craniospinal axis and CT scan of the whole body showed a T4aN0M0 tumor [UICC 8th Edition (Bertero et al., 2017)]. After transsphenoidal partial resection, the patient was presented in the Radiooncology Department for additive irradiation with particle therapy. In the clinical examination, besides the paresis of the N. abducens, a paresis of the N. hypoglossus and the N. glossopharyngeus were found. Headache of moderate intensity was present since surgery. The MRI scan showed residual tumor with contact to the sinus sphenoidalis and the dorsal nasal cavity as well as contact with the prepontine cistern. The tumor surrounds the basilar artery by 360° and has contact with the internal carotid artery and cavum Meckeli. (Figure A.1.1).
一位38岁女性，因左侧外展神经麻痹而有双重视力史:活检证实了斜坡脊索瘤的诊断。颅脊髓轴MRI分期及全身CT扫描显示T4aN0M0肿瘤[UICC第8版(Bertero et al.， 2017)]。经蝶窦部分切除后，患者在放射肿瘤科接受粒子治疗的附加照射。在临床检查中，除外展神经麻痹外，还发现舌下神经麻痹和舌咽部神经麻痹。手术后出现中度头痛。MRI扫描显示残余肿瘤与蝶窦、鼻腔背侧以及前庭池接触。肿瘤环绕基底动脉360°，并与颈内动脉及梅凯利腔接触。(图A.1.1)。
{"title":"Appendix A. Clinical Examples*","authors":"","doi":"10.1093/jicru_ndy022","DOIUrl":"https://doi.org/10.1093/jicru_ndy022","url":null,"abstract":"A 38-year-old woman with a history of double vision due to the paresis of the left N. abducens: a biopsy was performed to confirm the diagnosis of clivus chordoma. Staging with MRI of the craniospinal axis and CT scan of the whole body showed a T4aN0M0 tumor [UICC 8th Edition (Bertero et al., 2017)]. After transsphenoidal partial resection, the patient was presented in the Radiooncology Department for additive irradiation with particle therapy. In the clinical examination, besides the paresis of the N. abducens, a paresis of the N. hypoglossus and the N. glossopharyngeus were found. Headache of moderate intensity was present since surgery. The MRI scan showed residual tumor with contact to the sinus sphenoidalis and the dorsal nasal cavity as well as contact with the prepontine cistern. The tumor surrounds the basilar artery by 360° and has contact with the internal carotid artery and cavum Meckeli. (Figure A.1.1).","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"12 1","pages":"153 - 188"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81828353","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}
Treatment planning is a process to design radiation beams that yield the optimum balance between high dose conformation to the target tumor and sparing of normal tissue, and to evaluate the resultant RBE-weighted doses to the patient. Generally, treatment planning for ion-beam therapy is conceptually the same as that for proton-beam therapy with the major difference arising from the variability of the relative biological effectiveness (RBE). In protonbeam therapy, the RBE is recommended to be a fixed constant. While this is an approximation, which may be clinically useful for proton-beam therapy, it is not considered a practical approach today by most ionbeam therapy centers. The RBE in a field of ions varies as a function of energy, penetration depth, absorbed dose per fraction, tissue type, clinical endpoint and other quantities. In principle, all these dependencies should be considered. Unlike for intensity modulated radiation therapy (IMRT) with photons, a greater dependency of the delivered dose on the delivery parameters of dedicated proton and ion beam machines exists. Consequently, it is a standard in proton and carbon ion-beam therapy, that a direct optimization of the delivery parameters is performed with respect to RBE-weighted dose. In IMRT, the absorbed dose distribution is optimized first and in a second step, the delivery parameters are tailored to this absorbed dose. As a result, a list of all available beam delivery parameters is used by the treatment planning system when optimizing the absorbed dose distribution. The ion-beam-delivery systems to be discussed here are the 3D beam scanning system (active system) and the conventional technique using beam shaping elements like range modulators, range shifters, compensators, scattering systems (or wobblers), and collimators (passive system). A derivative beam-delivery method that dynamically uses a multi-leaf collimator in combination with a range shifter (layer-stacking method) will be briefly discussed. The ion beam delivery parameters to be optimized by the treatment planning system (TPS) for a scanning-beam delivery are, typically, the beam energy for each scan, the scan spot positions, and the spot size. The selected beam intensity level may then be adjusted in an intermediate step by the treatment control system, according to the capabilities of the machine and monitoring system.
{"title":"6. Treatment Planning","authors":"","doi":"10.1093/jicru_ndy024","DOIUrl":"https://doi.org/10.1093/jicru_ndy024","url":null,"abstract":"Treatment planning is a process to design radiation beams that yield the optimum balance between high dose conformation to the target tumor and sparing of normal tissue, and to evaluate the resultant RBE-weighted doses to the patient. Generally, treatment planning for ion-beam therapy is conceptually the same as that for proton-beam therapy with the major difference arising from the variability of the relative biological effectiveness (RBE). In protonbeam therapy, the RBE is recommended to be a fixed constant. While this is an approximation, which may be clinically useful for proton-beam therapy, it is not considered a practical approach today by most ionbeam therapy centers. The RBE in a field of ions varies as a function of energy, penetration depth, absorbed dose per fraction, tissue type, clinical endpoint and other quantities. In principle, all these dependencies should be considered. Unlike for intensity modulated radiation therapy (IMRT) with photons, a greater dependency of the delivered dose on the delivery parameters of dedicated proton and ion beam machines exists. Consequently, it is a standard in proton and carbon ion-beam therapy, that a direct optimization of the delivery parameters is performed with respect to RBE-weighted dose. In IMRT, the absorbed dose distribution is optimized first and in a second step, the delivery parameters are tailored to this absorbed dose. As a result, a list of all available beam delivery parameters is used by the treatment planning system when optimizing the absorbed dose distribution. The ion-beam-delivery systems to be discussed here are the 3D beam scanning system (active system) and the conventional technique using beam shaping elements like range modulators, range shifters, compensators, scattering systems (or wobblers), and collimators (passive system). A derivative beam-delivery method that dynamically uses a multi-leaf collimator in combination with a range shifter (layer-stacking method) will be briefly discussed. The ion beam delivery parameters to be optimized by the treatment planning system (TPS) for a scanning-beam delivery are, typically, the beam energy for each scan, the scan spot positions, and the spot size. The selected beam intensity level may then be adjusted in an intermediate step by the treatment control system, according to the capabilities of the machine and monitoring system.","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"1 1","pages":"106 - 85"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79118977","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}
The application of ion beams in tumor therapy is based on advantages related to their specific physical and radiobiological properties. Regarding the physical properties, the absorbed dose vs. depth profile characterized by the Bragg peak represents the major advantage as compared to conventional photon radiation. Both protons and heavier ions, however, show similar absorbed dose vs. depth profiles. The advantage of heavier ions such as carbon ions as compared to protons is their radiobiological properties, typically exhibiting the following features:
{"title":"2. Radiation Biology","authors":"","doi":"10.1093/jicru_ndy020","DOIUrl":"https://doi.org/10.1093/jicru_ndy020","url":null,"abstract":"The application of ion beams in tumor therapy is based on advantages related to their specific physical and radiobiological properties. Regarding the physical properties, the absorbed dose vs. depth profile characterized by the Bragg peak represents the major advantage as compared to conventional photon radiation. Both protons and heavier ions, however, show similar absorbed dose vs. depth profiles. The advantage of heavier ions such as carbon ions as compared to protons is their radiobiological properties, typically exhibiting the following features:","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"70 1","pages":"13 - 36"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80291291","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}
The practice for most patients in radiotherapy is still to generate a treatment plan, which is consequently used over the entire course of therapy, typically for 25–30 fractions. This leads to a number of systematic uncertainties associated with the generation of a treatment plan (imaging for treatment planning, contouring, dose calculation). Even as this practice gradually changes with the introduction of adaptive concepts, the mentioned systematic uncertainties apply to the number of fractions for which the plan is used. A second category of uncertainties is of random nature and can be separated into interfraction and intrafraction uncertainties. Most of these random uncertainties will show a tendency to average out over the number of fractions. All uncertainties taken together will inevitably lead to deviations between the delivered dose and the prescribed absorbed dose. For example, a random setup uncertainty will lead to a smearing out of the delivered dose but not to a shift of the dose distribution. A systematic error in the definition of the target point, however, will lead to a systematic shift of the delivered dose distribution in all subsequent fractions if not corrected. In ion-beam therapy uncertainties play a more important role for two reasons. First, a lower number of fractions is delivered, which may lead to a larger impact of random uncertainties. Second, the calculation of RBE-weighted dose, which is widely used, necessitates the use of biological models with inherently larger uncertainties in the input parameters. Consequently, the uncertainties involved in ion-beam therapy will be discussed below in more detail. Due to the nature of the underlying biological processes and their variations, the response of an organ or tumor to a radiation dose is not completely predictable. Only from a group of patients, meaningful parameters, that affect the outcome, can be derived statistically. In addition to these inherently probabilistic effects, there are also uncertainties connected to the underlying physical and clinical parameters on which the biological effects of radiation are dependent. To derive meaningful clinical results from the application of ion beams, these parameters should be specified, controlled, and if possible, kept to a reasonable accuracy and uncertainty level. Some of these parameters can, in principle, be determined by measurements while others are more difficult to determine precisely. Among the latter, there are all the treatment parameters, which are defined through the experience and expertise of the radiation oncologist. These are:
{"title":"8. Estimation and Presentation of Uncertainty in the Delivered Dose","authors":"","doi":"10.1093/jicru_ndy027","DOIUrl":"https://doi.org/10.1093/jicru_ndy027","url":null,"abstract":"The practice for most patients in radiotherapy is still to generate a treatment plan, which is consequently used over the entire course of therapy, typically for 25–30 fractions. This leads to a number of systematic uncertainties associated with the generation of a treatment plan (imaging for treatment planning, contouring, dose calculation). Even as this practice gradually changes with the introduction of adaptive concepts, the mentioned systematic uncertainties apply to the number of fractions for which the plan is used. A second category of uncertainties is of random nature and can be separated into interfraction and intrafraction uncertainties. Most of these random uncertainties will show a tendency to average out over the number of fractions. All uncertainties taken together will inevitably lead to deviations between the delivered dose and the prescribed absorbed dose. For example, a random setup uncertainty will lead to a smearing out of the delivered dose but not to a shift of the dose distribution. A systematic error in the definition of the target point, however, will lead to a systematic shift of the delivered dose distribution in all subsequent fractions if not corrected. In ion-beam therapy uncertainties play a more important role for two reasons. First, a lower number of fractions is delivered, which may lead to a larger impact of random uncertainties. Second, the calculation of RBE-weighted dose, which is widely used, necessitates the use of biological models with inherently larger uncertainties in the input parameters. Consequently, the uncertainties involved in ion-beam therapy will be discussed below in more detail. Due to the nature of the underlying biological processes and their variations, the response of an organ or tumor to a radiation dose is not completely predictable. Only from a group of patients, meaningful parameters, that affect the outcome, can be derived statistically. In addition to these inherently probabilistic effects, there are also uncertainties connected to the underlying physical and clinical parameters on which the biological effects of radiation are dependent. To derive meaningful clinical results from the application of ion beams, these parameters should be specified, controlled, and if possible, kept to a reasonable accuracy and uncertainty level. Some of these parameters can, in principle, be determined by measurements while others are more difficult to determine precisely. Among the latter, there are all the treatment parameters, which are defined through the experience and expertise of the radiation oncologist. These are:","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"36 1","pages":"123 - 132"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81090980","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}
As introduced in previous ICRU reports, concepts related to target volumes and normal tissues at risk have been defined for use in treatment planning and reporting processes for photon (Reports 50, 62, 83), electron (Report 71) and proton (Report 78) beams (ICRU, 1993b; 1999; 2010; 2004; 2007). Delineation of these volumes is an obligatory step in the planning process, as absorbed or RBE-weighted dose cannot be prescribed, reported and recorded without specification of target volumes and volumes of normal tissue at risk. These concepts are intended to be applicable to any type of radiation therapy modality, including ion-beam therapy. More specifically, these volumes are essential in beam optimization for specified dose-volume constraints, i.e., the inverse planning, which is common for IMRT, IMPT, and ionbeam therapy. The following volumes have been defined in previous ICRU reports:
{"title":"5. Volumes in Ion-Beam Therapy","authors":"","doi":"10.1093/jicru_ndz004","DOIUrl":"https://doi.org/10.1093/jicru_ndz004","url":null,"abstract":"As introduced in previous ICRU reports, concepts related to target volumes and normal tissues at risk have been defined for use in treatment planning and reporting processes for photon (Reports 50, 62, 83), electron (Report 71) and proton (Report 78) beams (ICRU, 1993b; 1999; 2010; 2004; 2007). Delineation of these volumes is an obligatory step in the planning process, as absorbed or RBE-weighted dose cannot be prescribed, reported and recorded without specification of target volumes and volumes of normal tissue at risk. These concepts are intended to be applicable to any type of radiation therapy modality, including ion-beam therapy. More specifically, these volumes are essential in beam optimization for specified dose-volume constraints, i.e., the inverse planning, which is common for IMRT, IMPT, and ionbeam therapy. The following volumes have been defined in previous ICRU reports:","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"4 1","pages":"71 - 84"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87851654","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}
One major advantage of ion-beam therapy in comparison to other radiation therapy techniques is the improved conformation of RBE-weighted dose to the clinical target volume (CTV) due to physical and biological characteristics. This is characterized by a absorbed dose vs. depth profile exhibited by a mono-energetic beam with a relatively low absorbed dose in the entrance region (plateau) and a sharp dose peak (Bragg peak) at the end of the finite range (which can be spread out to match the longitudinal extent of the PTV), little lateral scattering, and increased RBE in the target volume in comparison with the entrance region. To maintain the advantage of conformity over a course of ion-beam therapy, in addition to accounting for uncertainties due to beam parameters (e.g., position, spot size) that are discussed in Section 8, the target volume has to be positioned precisely for each treatment fraction. Two types of possible anatomical variations have to be considered to achieve adequate target volume positioning: (1) interfractional organ motion and (2) intrafractional organ motion. Apart from these internal changes of the patient’s anatomy, misalignment of the patient itself is typically constrained by dedicated immobilization equipment. In addition, imaging techniques in the treatment room may be employed to register the actual patient position to the planned position. Interfractional target motion occurs in a time-scale of hours to weeks, e.g., weight loss or radiationinduced effects such as tumor shrinkage, whereas intrafractional target motion occurs in a time-scale of seconds to minutes, e.g., respiration. An overview of organ motion and its management in radiation therapy is given elsewhere (Bert and Durante, 2011; Korreman, 2012; Langen and Jones, 2001). The management of motion in ion-beam therapy depends on the motion type. Ion-beam therapy should not be delivered to patients for whom adequate mitigation of motion and setup errors cannot be established. The following sections cover immobilization and patient positioning techniques (some of which are ion-beam-therapy specific) including imaging for treatment planning and patient position verification that deal with interfractional as well as intrafractional motion.
{"title":"7. The Management of Patient and Organ Motion and its Consequences","authors":"","doi":"10.1093/jicru_ndy019","DOIUrl":"https://doi.org/10.1093/jicru_ndy019","url":null,"abstract":"One major advantage of ion-beam therapy in comparison to other radiation therapy techniques is the improved conformation of RBE-weighted dose to the clinical target volume (CTV) due to physical and biological characteristics. This is characterized by a absorbed dose vs. depth profile exhibited by a mono-energetic beam with a relatively low absorbed dose in the entrance region (plateau) and a sharp dose peak (Bragg peak) at the end of the finite range (which can be spread out to match the longitudinal extent of the PTV), little lateral scattering, and increased RBE in the target volume in comparison with the entrance region. To maintain the advantage of conformity over a course of ion-beam therapy, in addition to accounting for uncertainties due to beam parameters (e.g., position, spot size) that are discussed in Section 8, the target volume has to be positioned precisely for each treatment fraction. Two types of possible anatomical variations have to be considered to achieve adequate target volume positioning: (1) interfractional organ motion and (2) intrafractional organ motion. Apart from these internal changes of the patient’s anatomy, misalignment of the patient itself is typically constrained by dedicated immobilization equipment. In addition, imaging techniques in the treatment room may be employed to register the actual patient position to the planned position. Interfractional target motion occurs in a time-scale of hours to weeks, e.g., weight loss or radiationinduced effects such as tumor shrinkage, whereas intrafractional target motion occurs in a time-scale of seconds to minutes, e.g., respiration. An overview of organ motion and its management in radiation therapy is given elsewhere (Bert and Durante, 2011; Korreman, 2012; Langen and Jones, 2001). The management of motion in ion-beam therapy depends on the motion type. Ion-beam therapy should not be delivered to patients for whom adequate mitigation of motion and setup errors cannot be established. The following sections cover immobilization and patient positioning techniques (some of which are ion-beam-therapy specific) including imaging for treatment planning and patient position verification that deal with interfractional as well as intrafractional motion.","PeriodicalId":91344,"journal":{"name":"Journal of the ICRU","volume":"80 1","pages":"107 - 122"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74976227","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}
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