乳腺癌根治术后VMAT大分割放疗的剂量学分析及疗效研究

Study on dosimetric analysis and efficacy of VMAT hypofractionated radiotherapy after breast cancer radical operation

目的探讨乳腺癌根治术后容积弧形调强放疗(VMAT)大分割放疗与调强适形放疗技术(IMRT)常规分割放疗的有效性及安全性。方法选取2021年3月1日至2021年12月30日该院收治的85例乳腺癌改良根治术患者为研究对象,按照随机数字表法分为VMAT组(n=41)与IMRT组(n=42)。VMAT组采用VMAT大分割放疗,单次分割剂量2.9 Gy/次,放疗总剂量43.5 Gy/15次;IMRT组采用IMRT常规分割放疗,单次分割剂量2.0 Gy/次,放疗总剂量50.0 Gy/25次。比较两组计划靶区V 95、V 110、适形指数、均匀指数、治疗时间,以及患侧肺V 5、V 20、V 30、平均剂量(D mean),肱骨头D mean和心脏V 30、D mean。同时比较两组肿瘤局部复发、远处转移、无病生存及急性、慢性放射性损伤发生情况。结果与IMRT组比较,VMAT组V 95更高,V 110、均匀指数更低,治疗时间更短,患侧肺V 5、D mean及患侧肱骨头D mean更低,患侧肺V 30更高,左侧乳腺癌的心脏V 30更低,右侧乳腺癌的心脏D mean更低,差异有统计学意义(P<0.05)。研究对象全部生存,无局部复发,两组远处转移率、无病生存率比较,差异无统计学意义(P>0.05)。随访12个月,两组Ⅰ~Ⅱ级急性放射性皮炎、放射性食管炎和慢性放射性皮炎、放射性肺炎发生率比较,差异无统计学意义(P>0.05),VMAT组Ⅰ~Ⅱ级肩关节功能障碍发生率低于IMRT组,差异有统计学意义(P<0.05)。两组均无Ⅱ级以上急、慢性放射性损伤发生。结论乳腺癌改良根治术后VMAT大分割放疗有效、安全。

Objective To investigate the effectiveness and safety of volumetric modulated arc therapy(VMAT)hypofractionated radiotherapy and intensity modulated conformal radiotherapy technique(IMRT)conventional fractionated radiotherapy after breast cancer radical operation.Methods Eighty-five patients with breast cancer modified radical operation admitted and treated in this hospital from March 1,2021 to December 30,2021 were selected as the research subjects and divided into the VMAT group(n=41)and the IMRT group(n=42)according to the random number table method.The VMAT group adopted the hypofractionated radiotherapy,with the single fractionated dose of 2.9 Gy/frequency and radiotherapeutic total dose of 43.5 Gy/15 frequencies;the IMRT group adopted the IMRT conventional fractionated radiotherapy,with the single fractionated dose of 2.0 Gy/frequency and radiotherapeutic total dose of 50.0 Gy/25 frequencies.The planning target region V 95,V 110,conformity index,homogeneity index,treatment time,V 5,V 20,V 30,average dose(D mean)in the affected side lung,humeral head D mean and heart V 30,D mean were compared between the two groups.Meanwhile,local recurrence,distant metastasis,disease-free survival and acute and chronic radiation injury were compared between the two groups.Results Compared with the IMRT group,V 95 in the VMAT was higher,V 110 and homogeneity index were lower,the treatment time was shorter,V 5 in the affected lung,D mean and D mean in the affected humeral head were lower,V 30 in the affected lung was higher,heart V 30 in the left side breast cancer was lower,heart D mean in the right side breast cancer was lower,and the differences were statistically significant(P<0.05).All patients survived without local relapse.The distant metastasis rate and disease free survival rate had no statistical difference between the two groups(P>0.05).Follow up lasted for 12 months,the incidence rates of gradeⅠ-Ⅱacute radiodermatitis,radiation esophagitis,chronic radiodermatitis and radiation pneumonia had no statistical differences between the two groups(P>0.05).The incidence rate of gradeⅠ-Ⅱshoulder dysfunction in the VMAT group was lower than that in the IMRT group with statistical difference(P<0.05).No gradeⅡand above acute and chronic radiation injury in the two groups occurred.Conclusion VMAT hypofractionated radiotherapy after breast cancer radical operation is safe and effective.