容积旋转调强放疗与固定野调强放疗在保留卵巢的宫颈癌根治术后放疗中的剂量学研究

Dosimetric Study of Volumetric Intensity-Modulated Arc Therapy and Intensity Modulated Radiation Therapy in Postoperative Radiotherapy for Cervical Cancer with Ovarian Preservation

目的比较容积旋转调强放疗(VMAT)和固定野调强放射治疗(IMRT)在保留卵巢的宫颈癌根治术后放疗中的剂量学特点。方法纳入完成保留卵巢的宫颈癌根治术的15例患者,每例患者均分别采用VMAT和IMRT两种技术制定放疗计划,分别比较2种放疗方法的靶区适形度(CI)和均匀性(HI)、危及器官(OARs)的剂量差异。结果应用VMAT放疗技术的肿瘤靶区CI为0.921±0.040,与IMRT相当(0.933±0.037)(P=0.263),而VMAT的HI为(1.068±0.024),优于IMRT(1.095±0.037)(P=0.02)。对于卵巢的保护,IMRT计划的V_(5)、V_(7)、D_(max)均小于VAMT计划(P<0.05)。对于其他正常组织,肠管V_(10)~V_(40)、膀胱V_(20)~V_(40)、直肠V _(20)~V_(46) IMRT均具有剂量学优势,但两种计划股骨头受量无明显差异。结论保留卵巢的宫颈癌根治术后调强放疗显示出更大的优势。

Objective To study the dosimetric characteristics of volumetric intensity modulated arc therapy(VMAT)and intensity modulated radiation therapy(IMRT)in postoperative radiotherapy for cervical cancer with ovarian preservation.Methods Including 15 patients who underwent radical cervicectomy for ovarian cancer,each patient was treated with VMAT and IMRT techniques to compare the target area conformity(CI),uniformity(HI),dose difference between organs(OARs).Results The tumor target area CI using VMAT radiotherapy was(0.921±0.040),which was comparable to IMRT(0.933±0.037)(P=0.263),while the VAMT had a HI of(1.068±0.024),which was better than IMRT(1.095±0.037)(P=0.02).For ovarian protection,the V_(5)、V_(7)、D_(max)of the IMRT plan were smaller than the VAMT plan(P<0.05).For other normal tissues,intestinal V_(10)~V_(40),bladder V;χ_(20)~V_(40),and rectal V_(20)~V_(46) IMRT all had dosimetric advantages,but there was no significant difference in femoral head volume between the 2 plans.Conclusion After the radical surgery of cervical cancer with ovarian preservation,intensity-modulated radiotherapy showed a greater advantage.