SU-E-T-202：统一扫描质子治疗机的综合质量保证程序。

Zheng Y, Ding X, Mascia A, Hsi W, Kang Y, Ramirez E, Zeidan O, Schreuder N

ProCure Proton Therapy Center, Oklahoma City, OK.

ProCure Treatment Centers, Bloomington, IN.

Med Phys. 2012 Jun;39(6Part12):3749. doi: 10.1118/1.4735262.

PURPOSE

Quality assurance (QA) is essential in safe and accurate delivery of radiation therapy. However, QA in proton therapy is challenging due to complicated and often facility-specific beam delivery systems and limited beam time for QA. The purpose of this study is to develop an efficient and comprehensive QA procedure for a multi-room proton therapy center using uniform scanning beams.

METHODS

Our proton therapy center is comprised of a 230 MeV cyclotron, one fixed beam room, two inclined beam rooms, and one gantry room. Uniform scanning is employed exclusively in all treatment rooms. A rfDaily QA3 (Sun Nuclear Inc., Melbourne, Florida) together with home-made devices is used for daily QA. Parallel plane chambers, a multi-layer ionization chamber array (Zebra, IBA dosimetry, Schwarzenbruck, German), and an IC profiler (Sun Nuclear Inc., Melbourne, Florida) are used to QA the characteristics of the uniform scanning beams, including output, range, modulation width, flatness, symmetry, and penumbra, for both monthly and annual QA. QA procedures and acceptance criteria were developed, taking into account the likelihood and potential risk of failure, as well as the available equipment, personnel and other resources.

RESULTS

QA procedures and tolerances were developed for daily, monthly and annual QA at our proton therapy center. Daily QA is performed by radiation therapists, and can be completed within 30 minutes for all rooms. Monthly QA and annual QA are performed by physicists, taking about 4 hours and a weekend respectively. Trend analysis was performed for various machine characteristics, such as machine output, range, flatness, and symmetry.

CONCLUSION

QA standards are desired in Radiation Oncology, but not many standards are developed and available for proton therapy. In the mean time, facility-specific QA procedures should be developed based on the equipment failure modes and available resources.

目的

质量保证（QA）对于安全、准确地实施放射治疗至关重要。然而，由于质子治疗中束流传输系统复杂且通常因设备而异，以及用于质量保证的束流时间有限，质子治疗中的质量保证具有挑战性。本研究的目的是为使用均匀扫描束的多室质子治疗中心开发一种高效、全面的质量保证程序。

方法

我们的质子治疗中心由一台230 MeV的回旋加速器、一个固定束室、两个倾斜束室和一个龙门室组成。所有治疗室均仅采用均匀扫描。使用射频每日质量保证3（Sun Nuclear公司，佛罗里达州墨尔本）以及自制设备进行每日质量保证。平行平面电离室、多层电离室阵列（Zebra，IBA剂量学公司，德国施瓦岑布吕克）和IC轮廓仪（Sun Nuclear公司，佛罗里达州墨尔本）用于每月和每年的质量保证，以检测均匀扫描束的特性，包括输出剂量、射程、调制宽度、平坦度、对称性和半值层。在考虑故障的可能性和潜在风险以及可用设备、人员和其他资源的基础上，制定了质量保证程序和验收标准。