应用多丝电离室实时监测剂量和MLC的研究

发布时间：2018-01-29 13:56

本文关键词： IMRT MLC 剂量 DAVID 实时监测　出处：《清华大学》2013年硕士论文　论文类型：学位论文

【摘要】：调强放射治疗（IMRT）通常利用加速器多叶光栅（MLC）形成多个不规则子野，其不同形状大小和剂量的子野叠加导致了对肿瘤靶区的适形以及对束流的调制，从而实现患者的束流照射。临床治疗过程中如何确保MLC形成子野的精确性以及加速器束流照射剂量的准确性则显得至关重要，这也是实现精确放疗有效性的重要保证。本文分析探讨了DAVID系统实施实时监测的特点和各项性能，对其治疗中监测功能的可行性与实用性进行了较为详细地研究。多丝电离室（DAVID）作为一种新型的质量保证设备，，可用于治疗过程中实时监测MLC形状和束流剂量。通过研究DAVID对射线束流的影响，评价DAVID对射野的检测精度和不同射野的可重复剂量，以及评估出DAVID对射野和剂量偏差的检测能力，从而奠定了该系统在患者临床应用中实时监测的理论基础和实验依据。最后比较了患者IMRT治疗中DAVID实时检测的数据，较为客观地总结出临床中DAVID实时监测的有效性及其应用价值。测试结果表明，治疗中DAVID系统能够较好地实现MLC叶片位置和剂量精度的验证和监测；但也存在一定的局限性，需要在临床实际应用中加以注意和克服。
[Abstract]:Intensity modulated radiotherapy (IMRT) usually uses the accelerator multileaf grating (MLC) to form multiple irregular subfields. The superposition of the subfields with different shapes and doses leads to the conformability of the tumor target and the modulation of the beam current. How to ensure the accuracy of the formation of subfields of MLC and the accuracy of the dose of accelerator beam irradiation is very important in the clinical treatment. This is also an important guarantee for the effectiveness of accurate radiotherapy. In this paper, the characteristics and performance of real-time monitoring in DAVID system are analyzed and discussed. The feasibility and practicability of the monitoring function in the treatment were studied in detail. The multifilament ionization chamber DAVIDD is a new type of quality assurance equipment. It can be used to monitor the shape and dose of MLC in real time in the course of treatment. By studying the effect of DAVID on beam, the accuracy of detection of beam field by DAVID and the repeatable dose of different field are evaluated. The ability of DAVID to detect field and dose deviation was evaluated. Thus, the theoretical basis and experimental basis of real-time monitoring of DAVID in clinical application of patients were established. Finally, the data of real-time detection of DAVID in patients with IMRT were compared. The effectiveness and application value of real-time monitoring of DAVID in clinic were summarized objectively. The test results show that the DAVID system can better verify and monitor the accuracy of MLC leaf position and dose. However, there are some limitations which need to be paid attention to and overcome in clinical practice.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R730.55

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