Deterministic Radiotherapy Dose Calculation Method

描述（由申请人提供）：临床上需要开发用于外射束放射治疗临床治疗计划的准确有效的剂量计算方法。由于图像引导定位技术的最新进展和更精确的射束输送方法（如调强放射治疗（IMRT））的发展，存在大幅减少裕度和改善剂量一致性的潜力。然而，目前临床使用的大多数剂量计算方法采用近似法，这限制了其准确性和使用范围，特别是在存在非均匀性的情况下使用窄射束。因此，行业正在迅速转向蒙特卡罗的临床采用。然而，蒙特卡罗计算是耗时的，限制了其临床治疗计划的有效性。在I期研究中，针对患者特定前列腺和头颈部病例，通过Monte Carlo验证了一种新型确定性剂量计算方法，该方法求解了中性和带电粒子的控制传输方程的微分形式。结果表明，该方法与蒙特卡罗方法一样精确，并能提供更高的空间精度。类似地，所提出的方法被证明比蒙特卡洛快得多，这可以转化为临床环境中更高的准确性。在第二阶段，将开发一个商业上可行的剂量计算系统，该系统可以集成到临床治疗计划系统中，其性能比第一阶段原型提高数倍。确认病例将由M.D.执行。安德森癌症中心，使用实验数据和回顾性患者计划。通过提供比现有临床剂量计算方法更上级的速度和准确性的组合，II期产品有可能提高美国每年接受光子束放射治疗的约650，000名患者的护理质量，以及全世界更多的人。此外，由于第二阶段的产品是基于第一原理数值方法，它最终可以适应其他放射治疗方式。通过为医生提供更准确的剂量评估，第二阶段研究有可能提高美国每年接受外照射放射治疗的65万人的护理质量。通过普遍适用的算法，最终得到的产品可以迁移到其他放射治疗模式的临床治疗计划。

DESCRIPTION (provided by applicant): A clinical need exists for the development of accurate and efficient dose calculation methods for clinical treatment planning in external beam radiotherapy. Due to recent advances in image guided localization techniques and the development of more precise beam delivery methods such as Intensity Modulated Radiation Therapy (IMRT), the potential exists to substantially reduce margins and improve dose conformity. However, most dose calculation methods in clinical use today employ approximations that limit their accuracy and scope of use, especially with narrow beams in the presence of heterogeneities. As a result, industry is moving rapidly towards the clinical adoption of Monte Carlo. However, Monte Carlo calculations are time consuming, limiting their effectiveness for clinical treatment planning. In the Phase I research, a novel deterministic dose calculation method, which solves the differential form of the governing transport equations for neutral and charged particles, was validated against Monte Carlo for patient specific prostate and head- and-neck cases. The results indicated that the proposed approach is as accurate as Monte Carlo, and can provide higher spatial precision. Similarly, the proposed approach was shown to be much faster than Monte Carlo, which can translate to improved accuracy in a clinical setting. In Phase II, a commercially viable dose calculation system will be developed which can be integrated into clinical treatment planning systems, with multi-fold performance gains over the Phase I prototype. Validation cases will be performed by M.D. Anderson Cancer Center, using both experimental data and retrospective patient plans. By providing a combination of speed and accuracy superior to existing clinical dose calculation methods, the Phase II product has the potential to improve quality of care for the approximately 650,000 patients receiving photon beam radiotherapy each year in the U.S., and for many more worldwide. In addition, since the Phase II product is based on first principles numerical methods, it can ultimately be adapted to other radiotherapy modalities. By providing physicians with more accurate dose assessments, the Phase II research has the potential to improve the quality of care for the 650,000 people receiving external beam radiotherapy in the United States each year. Through generally applicable algorithms, the resulting product can ultimately be migrated towards clinical treatment planning for other radiotherapy modalities.