Product Development of Intensity Modulation for Bolus Electron Conformal Therapy

推注电子适形治疗强度调制产品开发

• 批准号: 9199469
• 负责人: Kevin James Erhart
• 金额: $ 26.11万
• 依托单位: DECIMAL, INC.
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-13 至 2018-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9199469
• 关键词: Acute; Agreement; Air; Algorithms; Area; Bolus Infusion; Caliber; Cancer Control; Collimator; Computer software; Conformal Radiotherapy; Copper; Devices; Distal; Dose; Electron Beam; Electron Beam Therapy; Electrons; Goals; Guidelines; Heterogeneity; Island; Location; Malignant Neoplasms; Measurement; Measures; Methods; Mission; Modality; Modeling; Monte Carlo Method; Normal tissue morphology; Patients; Pattern; Penetration; Phase; Radiation; Radiation Oncologist; Radiation therapy; Reporting; Research; Risk; Second Primary Cancers; Site; Small Business Technology Transfer Research; Surface; System; Techniques; Technology; Testing; Time; Tissues; Variant; Water; abstracting; cancer therapy; density; design; improved; product development; quality assurance; radiation adverse effect; software development; tool; treatment planning

Project Summary/Abstract Electron beam therapy (EBT) using 6-20 MeV beams provides effective radiation treatment for superficial cancers (depth<6 cm). As many as 20% of radiotherapy patients (166,000 in USA annually) are eligible for electron therapy for some portion of their treatment, making it the second most used external beam modality. As many as 10% of these electron patients (16,600 annually) could benefit from bolus electron conformal therapy (ECT), a technique conforming the dose distribution (distal 90% isodose surface) to the targeted cancer volume while protecting surrounding healthy tissue from acute and long-term adverse effects of radiation, aligning with the agency mission to improve cancer treatment quality. Currently, radiation oncologists are limited in the use of bolus ECT because of dose heterogeneity (as great as 30%) in the targeted cancer volume due to multiple Coulomb scattering from the irregular proximal bolus surface. This Phase I application proposes to research and develop electron intensity modulation technology (planning software and delivery device), which when integrated with existing bolus ECT technology, can eliminate the dose heterogeneity problem, i.e., deliver a more uniform dose distribution (10% dose spread) to the targeted cancer volume. Availability of the proposed product, intensity modulated bolus ECT, should not only greatly improve current treatments of superficial cancers using electron radiotherapy (bolus ECT or otherwise), but in some cases provide an improved alternative to other radiation modalities (e.g. volumetric arc therapy or intensity modulated radio-therapy) by having (1) decreased chance of secondary cancers, (2) equally high chance of cancer control, and (3) equally low chance of acute normal tissue complications. The proposed delivery technology is an intensity modulator plate, which consists of a matrix of small-diameter, cylindrical island blocks imbedded in a low-density slab attached to the beam-defining, collimating insert. The magnitude of the intensity modulation is related to the fraction of beam area covered by the island blocks in a small overlying region. By properly varying the diameter and/or separation of these island blocks, electron scatter in air should result in a smoothly varying intensity pattern on the patient and/or bolus that restores the dose uniformity in the cancer target volume when using bolus ECT. Phase I goals will be to demonstrate proof of principle by (1) incorporating intensity modulation into the existing BolusECT software product, including a method for ‘segmenting’ the intensity pattern into an appropriate matrix of island blocks, (2) validating that the planning software modeling the island blocks produces expected results for select patient sites, and (3) validating delivery of the planned intensity modulated BolusECT beams by demonstrating agreement between delivered (measured) and planned (calculated) dose distributions in water.

项目总结/摘要 使用6-20 MeV射束的电子束治疗（EBT）为浅表肿瘤提供了有效的放射治疗。 癌症（深度<6 cm）。多达20%的放射治疗患者（美国每年166，000人）有资格接受 电子治疗的一部分，他们的治疗，使其成为第二个最常用的外部束 模态。多达10%的这些电子患者（每年16，600人）可以从团注电子中受益 适形治疗（ECT），一种使剂量分布（远端90%等剂量面）符合 靶向癌症体积，同时保护周围健康组织免受急性和长期不良反应 辐射的影响，与原子能机构提高癌症治疗质量的使命保持一致。目前， 由于剂量异质性（高达30%），放射肿瘤学家在使用团注ECT时受到限制。 由于来自不规则近端团表面的多个库仑散射，靶向癌症体积。 第一阶段申请提出研究和开发电子强度调制技术 （计划软件和输送设备），当与现有的大剂量ECT技术集成时，可以 消除剂量不均匀性问题，即，提供更均匀的剂量分布（≤ 10%剂量分布） 到目标癌症体积。拟议产品（调强大剂量ECT）的可用性应 不仅大大改善了目前使用电子放射治疗（团注ECT或 否则），但在某些情况下提供了对其他辐射模态（例如，体积 弧形疗法或调强放射疗法），其具有（1）降低的继发性癌症的机会，（2） 同样高的癌症控制机会，和（3）同样低的急性正常组织并发症机会。 所提出的递送技术是强度调制器板，其由以下矩阵组成： 小直径的圆柱形岛状块体嵌入附接至波束限定的低密度板中， 准直插件强度调制的大小与光束覆盖面积的分数有关 在一个小的覆盖区域的岛屿块。通过适当地改变它们的直径和/或间隔， 岛块，空气中的电子散射应导致患者上的平滑变化的强度图案 和/或当使用团式ECT时恢复癌症靶体积中的剂量均匀性的团式。 第一阶段的目标是通过以下方式证明原理：（1）将强度调制纳入 现有的BolusECT软件产品，包括将强度模式“分割”为 岛块的适当矩阵，（2）验证规划软件建模岛块 为选定的患者部位产生预期结果，以及（3）验证计划强度的输送 通过证明输送（测量）和计划之间的一致性来调制BolusECT双射束 （计算的）水中剂量分布。