大分割模式下FIF-IMRT和IMRT技术治疗左侧乳腺癌保乳术患者的剂量学参数比较

Comparison of Dosimetry Parameters between Hypofractionated FIF-IMRT and IMRT in the Treatment of Patients Undergoing Breast-conserving Surgery for Left Breast Cancer

目的:探究大分割模式下,野中野正向调强放疗(FIF-IMRT)和逆向调强放疗(IMRT)技术治疗左侧乳腺癌保乳术患者的剂量学参数差异。方法:选取2018年5月-2021年7月南通大学附属肿瘤医院收治的左侧乳腺癌保乳术后患者62例,分别制定FIF-IMRT、IMRT两种治疗计划。在满足计划靶体积(PTV)达到95%乳腺处方剂量的前提下,两种计划的PTV、危及器官(OAR)受量分布及机器跳数等剂量学参数差异。结果:FIF-IMRT计划的最大剂量(D_(max))及均匀性指数(HI)均高于IMRT计划,差异均有统计学意义(P<0.05),两种计划的靶区平均剂量(D_(mean))、V_(95)、V_(100)、V_(105)及适形度指数(CI)比较,差异均无统计学意义(P>0.05)。FIF-IMRT计划心脏及左肺V_(5)、V_(10)均低于IMRT计划,差异均有统计学意义(P<0.05),与此同时FIF-IMRT计划右乳及脊髓D_(mean)、D_(max)均低于IMRT计划,差异均有统计学意义(P<0.05),两种计划右肺D_(mean)、D_(max)及最小剂量(D_(min))剂量分布比较,差异均无统计学意义(P>0.05)。此外FIF-IMRT计划的机器跳数低于IMRT计划,差异有统计学意义(P<0.05)。结论:在左侧乳腺癌保乳术后大分割调强治疗中,与IMRT技术相比,FIF-IMRT均匀性略差,但在降低心脏及左肺低剂量照射区体积的优势较大,同时对右乳及脊髓的保护作用更显著,且机器损耗小。

Objective:To investigate the differences in dosimetry parameters between hypofractionated field-in-field intensity-modulated radiotherapy(FIF-IMRT)and intensity-modulated radiotherapy(IMRT)in the treatment of patients undergoing breast-conserving surgery for left breast cancer.Method:A total of 62 patients with left breast cancer after breast-conserving surgery admitted to Tumor Hospital Affiliated to Nantong University from May 2018 to July 2021 were selected,two treatment plans,FIF-IMRT and IMRT,were made respectively.On the premise that the planning target volume(PTV)reached 95%of the prescribed dose,dosimetry parameters such as PTV,dose distribution of organ at risk(OAR)and machine hop count were compared between the two plans.Result:The maximum dose(D_(max))and homogeneity index(HI)in the FIF-IMRT plan were higher than those in the IMRT plan,the differences were statistically significant(P<0.05).There were no statistically significant differences in mean dose(D_(mean)),V_(95),V_(100),V_(105)and conformity index(CI)between the two plans(P>0.05).Heart and left lung V_(5)and V_(10)in the FIF-IMRT plan were lower than those in the IMRT plan,the differences were statistically significant(P<0.05).D_(mean),D_(max)and D_(min)of right breast and spinal cord in the FIF-IMRT plan were lower than those in the IMRT plan,the differences were statistically significant(P<0.05).There were no statistically significant differences in D_(mean),D_(max)and minimum dose(D_(min))of the right lung(P>0.05).Machine hop count in the FIF-IMRT plan was lower than that of IMRT plan,the difference was statistically significant(P<0.05).Conclusion:Compared with hypofractionated IMRT,the uniformity of hypofractionated FIF-IMRT is slightly worse after breast-conserving surgery for left breast cancer,but it has more advantages in reducing the volume of low-dose radiation area in heart and left lung,in addition,it can better protect on right breast and spinal cord,with less machine loss.