Jaw tracking技术在食管癌调强放射治疗中的临床应用

Clinical application of Jaw tracking technology in intensity modulated radiotherapy for esophageal cancer

目的利用三维治疗计划系统对食道癌调强放射治疗(IMRT)计划中铅门是否跟随作剂量学比较,评价其剂量差异。方法选择25例食道癌患者,利用Eclipse治疗计划系统对每例患者计划分别模拟铅门锁定、铅门跟随这两种情况,同时运用AAA、AXB两种算法,比较靶区和危及器官照射剂量、计划总调数。结果在铅门锁定、铅门跟随发现,AAA算法中,AAAJF左肺(V_(5)、V_(10)、V_(20)、V_(30))剂量高于AAAJT肺(V_(5)、V_(10)、V_(20)、V_(30))剂量8.4%,5.7%,4.9%,4.6%;AAAJF脊髓MAX均值高于AAAJT脊髓MAX均值1.68%;AAAJF心脏V30高于AAAJT心脏V30剂量1.15 cGy,心脏V40剂量高0.42 cGy;AAAJF组MU略低于AAAJT组MU值的3.7%;AAAJT组CI略优于AAAJF组CI值;AAAJF组和AAAJT组左肺V5的t检验P=0.007,右肺V5的t检验P=0.022。在AXB算法中比较得出相同规律。结论铅门跟随技术可以有效地降低危及器官的受量,同时使靶区的均匀性更好和适行度更高。

【Objective】To compare the dosimetry of lead in the intensity modulated radiotherapy(IMRT)for esophageal cancer and evaluate the dose difference.【Methods】Twenty-five patients with esophageal cancer were selected,and the Eclipse treatment planning system was used to simulate the two situations of lead door locking and lead door following respectively for each patient's plan.At the same time,AAA and AXB were used to compare the irradiation dose of target area and organs at risk and the total number of plan.【Results】Compared with those in Tracking group,V_(5)、V_(10)、V_(20)、V_(30)of left lungs in Fixed group were increased by an average of 8.4%,5.7%,4.9%,4.6%;DMAX of spinal cord was increased by 1.68%;V_(30),V_(40)of heart were increased by 1.15 cGy and 0.42 cGy;MU was reduced by 3.7%;respectively,P between Tracking group and Fixed group of V5 of left lungs were equal to 0.007 and right lungs were equal to 0.022,with statistical differences(P<0.05).The same conclusion is obtained in algorithm AXB.【Conclusion】Jaw tracking technique can further decrease the doses to organs-at-risk,at the same time,the conformity index of the target area is higher and the homogeneity index is better.