摘要
目的:分析比较固定野调强技术和不同弧数的旋转容积调强在宫颈癌骨髓保护根治性全盆腔放射治疗的剂量学特点,寻找更优的治疗方案。方法:选取在汕头大学医学院附属肿瘤医院接受根治性放疗的ⅡA-ⅡB期宫颈癌患者9例,针对每例患者分别设计九野固定野调强(FF—IMRT)计划、双弧、三弧和四弧旋转容积调强(2A—VMAT、3A—VMAT、4VMAT)计划,比较四者靶区、骨盆骨髓,其他危及器官的剂量学差异和加速器跳数和照射时间。结果:IMRT、2A—VMAT、3A—VMAT和4A—VMAT四组计划均具有良好的靶区覆盖率,靶区适形度和均匀性以及骨盆骨髓受照剂量和受照体积(V10,V10,V40)无差异。三组VMAT计划在危及器官的保护上无差异。VMAT计划的小肠均略低于FF—IMRT计划(P〈0.008),在直肠的保护上,FF—IMRT计划略优于3弧VMAT计划(P〈O.008)。IMRT、2A—VMAT.3A—VMAT和4A—VMAT计划的加速器跳数分别为(1850.3±227.8)MU、(848.4±58.8)MU、(835.0±76.2)MU和(910.8±43.3)MU,照射时间分别为(353.2±25.1)s、(136.2±3.6)s、(211.2±3.5)s和(286.2±3.4)S。各组的加速器跳数和照射时间比较差异有统计学意义,调强计划的跳数和照射时间最多,两弧VMAT最少。结论:综合考虑各种物理和生物因素,在宫颈癌骨髓保护根治性放疗计划中,双弧VMAT技术照射为最优选择。
Objective: To compare static intensity-modulated radiation therapy ( IMRT ) technique with various arcs of volumetric-modulated arc radiation therapy ( VMAT ) techniques in patients with cervical cancer treated with definitive bone morrow-sparing whole pelvic radiotherapy, and to explore a better treatment management. Method: 9 CT image sets of staged ⅡA-ⅡB cervical cancer patients, treated in Cancer Hospital of Shantou University Medical College, were included. Nine fixed-field IMRT ( FF-IMRT ) plans and two arcs, three ares, four arcs VMAT plans ( 2A- VMAT, 3A-VMAT, 4A-VMAT ) were created and compared for each patient. Plans were evaluated on parameters of tumor target volume, pelvic bone marrow ( PBM ), other pelvic organs, plan MUs and delivery time. Result: Four groups of 2A-VMAT, 3A-VMAT, 4A-VMAT and IMRT plans provide equivalent tumor target volume coverage, conformity, homogeneity and sparing of PBM respected to V10, V20, V40. Three VMAT plans demonstrate the similar organs sparing. VMAT was slightly superior to FF-IMRT with the sparing of bowel. However, FF-IMRT showed better rectum sparing than that of 3A-VMAT. The monitor units of IMRT, 2A-VMAT, 3A-VMAT and 4A-VMAT were ( 1850.3 ± 227.8 ) MU, ( 848.4± 58.8 ) MU, ( 835.0± 76.2 ) MU and ( 910.8±43.3 ) MU, respectively, while delivery time were ( 353.2 ±25.1 ) s, ( 136.2 ± 3.6 ) s, ( 211.2 ± 3.5 ) s and ( 286.2±3.4 ) s, respectively. There were significant differences of monitor units ( MUs ) and treatment time among four plans. IMRT plan had more MUs and treatment time than that of VMAT plans, and two arcs VMAT plan had the least MUs and treatment time. Conclusion: Considering the physical factors and biological effects during the cervical cancer definitive radiotherapy with pelvic bone marrow-sparing, 2 arcs VMAT plan would be the best choice for the treatment planning.
出处
《中国医学创新》
CAS
2015年第10期41-45,共5页
Medical Innovation of China
关键词
宫颈癌
骨髓
放射治疗
固定野调强
容积调强
Cervical cancer
Bone marrow
Radiotherapy
Static intensity-modulated radiation therapy
Volumetric-modulated arc radiation therapy