摘要
目的探讨用JR1152F型热释光剂量计(TLD)和仿真人体盆腔模型核查宫颈癌腔内后装治疗三维剂量分布的可行性。方法测定JR1152-F-型TLD(规格1mm×1mm×6mm)用于铱-192剂量测量的升温程序、剂量线性响应范围和重复性,并对TLD剂量计及热释光剂量仪(FJ427-A1)进行剂量刻度,仿真人体盆腔模型分成6段、每一层面关键器官上设置若干直径1mm、长6mm的测试孔,孔中放入直径1mm、长6mm小铅条,插入宫腔管施源器,模拟机下拍摄X光定位片,取出铅条,测试孔内放入TLD剂量计,用microSelectronHDR后装治疗计划系统(TPS)设计腔内放疗模拟计划,给予A点剂量200cGy次,计算出各测试点的理论值和重建精度,按计划进行腔内后装照射,用热释光剂量仪对受照后的TLD剂量计进行重复测量。结果TLD剂量计剂量线性范围在300cGy内,相关系数0.997,重复性好于±4%,A点、B点、F点、膀胱和直肠剂量参考点实测剂量与TPS计算值符合较好,误差分别在±3.60%、±0.9%、±7.8%、±7.1%、6.4%内。结论用JR1152-F型TLD和仿真人体盆腔模型核查宫颈癌腔内后装治疗三维剂量分布准确、可靠。
Objective To investigate the feasibility of checking the 3D - dose distribution of ^192Ir HDR intracavitary brachytherapy for cervix cancer patients by TLD and anthropomorphic pelvic phantom. Methods The heating program, the range of dose linear response, the reproducibility and the calibration factor of the TLD （JR1152 - F, 1 mm × 1 mm × 6 mm） were determined. The tissue equivalent pelvic phantom was cut into six segments and a set of small holes （φ1 × 6 mm ） were drilled at the interesting organs on each segment to hold the TLDs. The lead markers （φ1 ×6mm） were placed in the holes. After the tandem catheter had been put into the treatment position, the orthogonal X-films could be taken and the lead markers were replaced by the TLDs. An orthogonal radiography - based brachytherapy treatment planning was designed by microSeleetron HDR treatment planning system（TPS） with the prescription dose to Point A of 200 cGy. The doses to each measuring position were calculated. After the treatment plan was delivered, the doses to each TLD were measured by dosimeter. Results The range of dose linear response of the TLD is within 300 cGy with correlation coefficient of 0.997. The average reproducibility is less than ±4.0%. The calculated and measured dose values are in good coincidence at Pont A, Point B, Point F, bladder and rectum reference points. The relative errors for those positions are within ± 3.6%, ± 0.9%, ± 7.8%, ± 7.1% and 6.4%, respectively. Conclusion The JR1152 - F TLD and the anthropomorphic pelvic phantom are accurate and reliable in checking the 3D- dose distribution of ^192Ir HDR intracavitary brachytherapy for cervix cancer patients.
出处
《中国辐射卫生》
北大核心
2005年第3期167-169,共3页
Chinese Journal of Radiological Health
基金
广东省医学科研基金:批准号A2004577
广东省科技计划资助项目:批准号C30601
关键词
宫颈肿瘤
放射疗法
近距离治疗
热释光剂量计
Cervical Cancer
Radiation Therapy
Brachytherapy
Thermoluminescence Dosimeter
