Beddar A Sam, Krishnan Sunil, Briere Tina M, Wang Xiaochun, Delclos Marc E, Ballo Matthew T, Das Prajnan, Gould Spencer, Horton John L, Crane Christopher H
Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
Radiother Oncol. 2006 Feb;78(2):207-12. doi: 10.1016/j.radonc.2005.11.013. Epub 2006 Jan 10.
To determine the effect of the curvature of Harrison-Anderson-Mick applicators on the dose distribution in high-dose-rate intraoperative radiation therapy (HDR-IORT).
Treatment planning was performed with flat applicators using (192)Ir as the radioactive source, and dwell times were optimized using dose-point optimization techniques. These optimized dwell times were then used for the curved applicators, and the dose distributions that would actually be delivered to patients were determined.
The dose directly below the central catheter was strongly dependent on the curvature of the applicator. Steep parabolic curves caused underdoses of as much as 19% at a point 1cm from the convex side of the applicator. The rate of dose reduction with increasing distance from the applicator surface was also a function of the curvature of the applicator.
The curvature of the applicator profoundly affects dosimetry and can be exploited to optimize coverage of the target during HDR-IORT procedures. To ensure accurate dose delivery, these dose perturbations must be accounted for in the planning process. We recommend maintaining a dosimetry atlas of various applicator sizes and curvatures in addition to one for flat applicators.
确定哈里森 - 安德森 - 米克施源器的曲率对高剂量率术中放射治疗（HDR - IORT）剂量分布的影响。
使用以铱 - 192作为放射源的扁平施源器进行治疗计划，并采用剂量点优化技术优化驻留时间。然后将这些优化后的驻留时间用于弯曲施源器，并确定实际将给予患者的剂量分布。
中心导管正下方的剂量强烈依赖于施源器的曲率。在距施源器凸面1厘米处，陡峭的抛物线曲线导致剂量不足高达19%。随着距施源器表面距离增加，剂量降低率也是施源器曲率的函数。
施源器的曲率对剂量测定有深远影响，可在HDR - IORT程序中利用其优化靶区覆盖。为确保准确的剂量传递，在计划过程中必须考虑这些剂量扰动。除了扁平施源器的剂量测定图谱外，我们建议保留各种施源器尺寸和曲率的剂量测定图谱。
