Deterministic Radiotherapy Dose Calculation Method

描述(申请人提供)：临床需要发展准确和有效的剂量计算方法，用于临床治疗计划的体外放射治疗。由于图像引导定位技术的最新进展和更精确的射束传输方法的发展，如调强放射治疗(IMRT)，存在显著降低边缘和改善剂量一致性的潜力。然而，今天临床上使用的大多数剂量计算方法使用的近似限制了它们的精度和使用范围，特别是在存在不均匀的窄束的情况下。因此，业界正在迅速转向蒙特卡洛的临床应用。然而，蒙特卡罗计算非常耗时，限制了其在临床治疗计划中的有效性。在第一阶段的研究中，一种新的确定性剂量计算方法，该方法求解了中性粒子和带电粒子的控制输运方程的微分形式，并针对患者特定的前列腺和头颈部病例进行了蒙特卡罗验证。结果表明，该方法具有与蒙特卡罗方法相同的精度，并能提供更高的空间精度。同样，所提出的方法被证明比蒙特卡罗方法快得多，后者可以在临床环境中转化为更高的准确性。在第二阶段，将开发一种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，性能比第一阶段原型提高数倍。验证病例将由M.D.安德森癌症中心进行，使用实验数据和回顾患者计划。通过提供优于现有临床剂量计算方法的速度和准确性的组合，第二阶段产品有可能改善美国每年约65万名接受光子束放射治疗的患者以及世界各地更多患者的护理质量。此外，由于第二阶段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形式。通过为医生提供更准确的剂量评估，第二阶段研究有可能改善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移植到其他放射治疗方式的临床治疗计划中。

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.