Product Development of Intensity Modulation for Bolus Electron Conformal Therapy

项目摘要/摘要 目的：本项目旨在提升电子束治疗(EBT)技术，为临床提供有效的治疗手段 浅表性癌的放射治疗(深度6厘米)，与其他外照射疗法(XRT)相比， 例如X射线和质子，通过将电子强度调制引入临床。挑战：大约 10%的放射治疗患者(美国每年的为173,000人)在治疗过程中接受体外反转录病毒治疗， 其中多达10%的人(每年17,300人)可能受益于团注电子适形疗法，这 使远端90%剂量面符合肿瘤计划靶区体积(PTV)，保护邻近 健康的组织。目前，放射肿瘤学家在使用BECT方面受到限制，因为PTV剂量扩散可以作为 由于不规则的团块表面，高达30%。通过空间调制入射可以将其降低到10% 电子束强度。到目前为止，电子强度调制传输技术还不可用。 创新：使用我们的研究合作者最近发明的电子强度调制器设计，第一阶段 演示了PRIME(电子无源放射治疗强度调制器)的原理证明 DECIMAL为其开发了一种制造方法的低成本技术。素数由一组小的- 直径，圆柱形的钨岛块嵌入低密度泡沫中的光束定义， 准直光圈。放置在六角形网格上的不同直径的岛块可获得所需的强度 调制。然而，由于当前的治疗计划系统(TPS)不能管理素数，因此 电子TPS也需要开发。研究设计：第二阶段的具体目标包括(1)提炼 用于岛块下剂量计算的铅笔束重定义算法，(2)生成和评估 电子专用TPS，彗星计划(计算机优化和调制电子治疗计划)， 计划强度调制团注电子适形疗法(IM-BECT)和常规EBT， 管理皮肤准直器和眼罩等治疗辅助设备，(3)开发工厂和临床产品 质量保证方法，(4)进行多机构治疗计划研究，以确定 IM-BECT改进BECT剂量计划的程度，以及(5)通过以下方式验证IM-BECT计划和交付 将拟人模型中测量的剂量与计划(计算)的剂量进行比较。健康益处： Prime设备和Comet-Plan软件将允许一种新技术，IM-BECT，它提供统一的 符合PTV的剂量，导致(1)同样高的癌症控制机会，(2)同等或更好的低 急性正常组织并发症的机会；(3)减少继发性癌症的机会。对一些人来说 患者，这将提供比其他XRT方式更好的剂量分布，如体积弧形疗法 或螺旋断层治疗，改善他们的癌症治疗。商业化：作为世界领先的 一家生产针对患者的放射治疗设备的公司，我们装备精良，可提供最佳强度 调制器和COMET-PLAN软件提供给放射治疗诊所，支持激动人心的新型IM-BECT。

Project Summary/Abstract Objective: This project aims to elevate electron beam therapy (EBT) technology, which provides effective radiation treatment for superficial cancers (depth<6 cm), to that of other external beam radiotherapies (XRT), e.g. x-rays and protons, by bringing electron intensity modulation into the clinic. Challenge: Approximately 10% of radiotherapy patients (173,000 in USA annually) receive EBT for a portion of their treatment, and as many as 10% of these (17,300 annually) might benefit from bolus electron conformal therapy (BECT), which conforms the distal 90% dose surface to the cancerous planning target volume (PTV), protecting adjacent healthy tissue. Currently, radiation oncologists are limited in using BECT because PTV dose spread can be as great as 30% due to irregular bolus surface. This can be reduced to 10% by spatially modulating incident electron beam intensity. Heretofore, electron intensity modulation delivery technology has been unavailable. Innovation: Using our research collaborator’s recently invented electron intensity modulator design, Phase I demonstrated proof-of-principle for a PRIME (Passive Radiotherapy Intensity Modulator for Electrons), a low cost technology for which .decimal developed a fabrication method. PRIME consists of a matrix of small- diameter, cylindrical tungsten island blocks imbedded in a low-density foam in the beam-defining, collimating aperture. Varying diameters of island blocks placed on a hexagonal grid achieves desired intensity modulation. However, because current treatment planning systems (TPS) cannot manage PRIMEs, an electron TPS needs to be developed as well. Research Design: Phase II specific aims include (1) refining the pencil beam redefinition algorithm used for dose calculation under island blocks, (2) creating and evaluating an electron specific TPS, COMET-Plan (Computer Optimized & Modulated Electron Therapy Planning), which plans intensity modulated bolus electron conformal therapy (IM-BECT) and conventional EBT, managing treatment aids such as skin collimators and eye shields, (3) developing factory and clinical PRIME quality assurance methods, (4) performing a multi-institutional treatment planning study to determine the degree to which IM-BECT improves BECT dose plans, and (5) validating IM-BECT planning and delivery by comparing doses measured in anthropomorphic phantoms with planned (calculated) doses. Health Benefit: PRIME devices and COMET-Plan software will allow a new technique, IM-BECT, which provides uniform dose conforming to the PTV, resulting in (1) equally high chance of cancer control, (2) equally or better low chance of acute normal tissue complications, and (3) decreased chance of secondary cancers. For some patients, this will provide a better dose distribution than other XRT modalities, such as volumetric arc therapy or helical tomotherapy, improving their cancer treatment. Commercialization: As the world’s leading company producing patient-specific radiotherapy devices we are well equipped for bringing PRIME intensity modulators and COMET-Plan software to radiotherapy clinics, supporting the exciting, new IM-BECT.