Optimized IMRT Incorporating Beam Delivery

优化的 IMRT 结合射束传输

基本信息

批准号：
6765805
负责人：
JEFFREY Vincent SIEBERS
金额：
$ 26.7万
依托单位：
VIRGINIA COMMONWEALTH UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2003
资助国家：
美国
起止时间：
2003-07-01 至 2007-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6765805
关键词：
behavioral /social science research tag clinical research health care quality health services research tag human data human tissue mathematical model medical records method development neoplasm /cancer radiation therapy outcomes research patient care management patient care planning patient safety /medical error radiation therapy dosage statistics /biometry

项目摘要

DESCRIPTION (provided by applicant): Intensity Modulated Radiation Therapy (IMRT) seeks to deliver highly conformal tumorcidal doses to selected target volumes while conformably avoiding nearby normal tissues and critical structures. IMRT assumes that the optimized planned doses can be precisely and accurately delivered to the patient and that the final plan is optimal relative to the desired treatment objectives. Yet, current IMRT planning systems use simplified fast dose calculations during plan optimization and divides optimization and plan delivery into separate processes. The simplified dose computations can result in dose prediction errors (DPEs), which are differences between actual and computed doses, of 10% or more, while optimization with algorithms that have DPEs and the transformation from optimized to deliverable parameter spaces lead to optimization convergence errors (OCEs). OCEs prevent the true optimal plan from being found and can result in critical structure doses that are as much as 20% greater than necessary. Since dose differences of 3%-5% can produce clinically detectable changes in response, DPEs and OCEs may significantly impact clinical outcome. The goals of this project are: (1) To develop accurate IMRT dose-calculation methods that reduce DPEs to clinically insignificant levels. Monte Carlo (MC) methods will be used to evaluate the sources and clinical impacts of DPEs caused by patient heterogeneities, incident fluence prediction, and patient set-up errors and to identify and develop methods to reduce IMRT dose-calculation errors to less than 2% for all patient cases. (2) To develop optimization processes that reduces OCEs to clinically insignificant levels. This will be achieved by incorporating algorithms, identified in goal 1, that accurately model radiation transport through the multi-leaf collimator and the patient into the IMRT optimization process. Such deliverable optimization will allow each intensity-modulated beam to partially compensate for the limitations of other beams and may result in significantly reduced doses to critical Istructures for the same planning target volume dose. (3) To improve the computational efficiency of accurate Ideliverable-optimization processes developed in goal 2 to make them clinically practical without compromising plan laccuracy or optimality. This will allow accurate, deliverable optimized plans to be used for routine clinical IMRT, Iwhere previously it was not practical due to the excessive calculation time required. The long-term objectives of' this project are to develop rapid, accurate IMRT dose calculation and optimization} methods that result in minimal dose prediction and optimization convergence errors, to use these more accurate IRMT to accumulate more reliable dose-response data, and to improve patient outcomes through more conformal.

描述（由申请人提供）：调强放射治疗（IMRT）旨在向选定的靶区提供高度适形的肿瘤杀伤剂量，同时适形地避开附近的正常组织和关键结构。 IMRT 假设优化的计划剂量可以精确且准确地传递给患者，并且最终计划相对于所需的治疗目标是最佳的。然而，当前的 IMRT 计划系统在计划优化期间使用简化的快速剂量计算，并将优化和计划交付划分为单独的过程。简化的剂量计算可能会导致剂量预测误差 (DPE)，即实际剂量和计算剂量之间的差异，达到 10% 或更多，而使用具有 DPE 的算法进行优化以及从优化到可交付参数空间的转换会导致优化收敛误差（OCE）。 OCE 会阻碍找到真正的最佳计划，并可能导致关键结构剂量比所需剂量高出 20%。由于 3%-5% 的剂量差异可产生临床可检测的反应变化，因此 DPE 和 OCE 可能会显着影响临床结果。该项目的目标是： (1) 开发准确的 IMRT 剂量计算方法，将 DPE 降低到临床上无意义的水平。蒙特卡罗 (MC) 方法将用于评估由患者异质性、事件注量预测和患者设置错误引起的 DPE 的来源和临床影响，并确定和开发将 IMRT 剂量计算误差减少到小于 2 的方法所有患者病例的%。 (2) 开发优化流程，将 OCE 降低至临床上无意义的水平。这将通过将目标 1 中确定的算法合并到 IMRT 优化过程中来实现，该算法可以准确地模拟通过多叶准直器和患者的辐射传输。这种可传递优化将允许每个强度调制光束部分补偿其他光束的限制，并且可能导致对于相同的计划目标体积剂量显着减少关键结构的剂量。 (3) 提高目标 2 中开发的精确 Ideliverable 优化过程的计算效率，使其在临床上实用，而不影响计划的准确性或最优性。这将使准确的、可交付的优化计划用于常规临床 IMRT，而以前由于需要过多的计算时间而无法实现。该项目的长期目标是开发快速、准确的 IMRT 剂量计算和优化方法，以最小化剂量预测和优化收敛误差，利用这些更准确的 IRMT 积累更可靠的剂量反应数据，并通过更适形来改善患者的治疗效果。