Bahreyni Toossi Mohammad Taghi, Ghorbani Mahdi, Makhdoumi Yasha, Taheri Mojtaba, Homaee Shandiz Fatemeh, Zahed Anaraki Siavash, Soleimani Meigooni Ali
Medical Physics Research Center, Faculty of Medicine, Pardise Daneshgah, Mashhad University of Medical Sciences, Azadi Square, Mashhad, Iran.
North Khorasan University of Medical Sciences, Bojnurd, Iran.
Rep Pract Oncol Radiother. 2012 Jul 15;17(6):352-7. doi: 10.1016/j.rpor.2012.06.002. eCollection 2012.
The aim of this work is to evaluate rectal and bladder dose for the patients treated for gynecological cancers.
The GZP6 high dose rate brachytherapy system has been recently introduced to a number of radiation therapy departments in Iran, for treatment of various tumor sites such as cervix and vagina.
Our analysis was based on dose measurements for 40 insertions in 28 patients, treated by a GZP6 unit between June 2009 and November 2010. Treatments consisted of combined teletherapy and intracavitary brachytherapy. In vivo dosimetry was performed with TLD-400 chips and TLD-100 microcubes in the rectum and bladder.
The average of maximum rectal and bladder dose values were found to be 7.62 Gy (range 1.72-18.55 Gy) and 5.17 Gy (range 0.72-15.85 Gy), respectively. It has been recommended by the ICRU that the maximum dose to the rectum and bladder in intracavitary treatment of vaginal or cervical cancer should be lower than 80% of the prescribed dose to point A in the Manchester system. In this study, of the total number of 40 insertions, maximum rectal dose in 29 insertions (72.5% of treatment sessions) and maximum bladder dose in 18 insertions (45% of treatments sessions) were higher than 80% of the prescribed dose to the point of dose prescription.
In vivo dosimetry for patients undergoing treatment by GZP6 brachytherapy system can be used for evaluation of the quality of brachytherapy treatments by this system. This information could be used as a base for developing the strategy for treatment of patients treated with GZP6 system.
本研究旨在评估接受妇科癌症治疗患者的直肠和膀胱剂量。
GZP6高剂量率近距离放射治疗系统最近已被引入伊朗的多个放射治疗科室，用于治疗各种肿瘤部位，如子宫颈和阴道。
我们的分析基于2009年6月至2010年11月期间使用GZP6设备治疗的28例患者的40次插入剂量测量。治疗包括外照射和腔内近距离放射治疗。使用TLD - 400芯片和TLD - 100微立方体在直肠和膀胱中进行体内剂量测定。
直肠和膀胱最大剂量值的平均值分别为7.62 Gy（范围1.72 - 18.55 Gy）和5.17 Gy（范围0.72 - 15.85 Gy）。国际辐射单位与测量委员会（ICRU）建议，在阴道或子宫颈癌腔内治疗中，直肠和膀胱的最大剂量应低于曼彻斯特系统中A点处方剂量的80%。在本研究中，在总共40次插入中，29次插入（占治疗疗程的72.5%）的直肠最大剂量和18次插入（占治疗疗程的45%）的膀胱最大剂量高于剂量处方点规定剂量的80%。
对于接受GZP6近距离放射治疗系统治疗的患者，体内剂量测定可用于评估该系统近距离放射治疗的质量。该信息可作为制定使用GZP6系统治疗患者策略的基础。
