Application of electronic portal imaging device in postoperative intensity modulated radiotherapy of rectal cancer / 医疗卫生装备

Objective To measure and analyze the set-up errors of postoperative intensity modulated radiation therapy of rectal cancer (PIMRTRC)with electronic portal imaging device (EPID),and to provide theoretical foundation for clinical realizing of accurate PIMRTRC.Methods Totally 30 patients after rectal carcinoma resection underwent sagittal and coronal photographing with EPID before the first time of therapy and one time per week during the treatment course.The obtained images were compared with DRR images in treatment planning system to get the setup errors at X(left-right),Y(head-foot) and Z (front-back)directions,and the extending margins of CTV and PTV in postoperative intensity modulated radiation therapy were calculated.EPID was used for setup correction,and SPSS 19.0 was involved in to execute statistical analysis. Results The linear displacement had the mean values plus/minus standard deviation at X, Y and Z directions before and after error correction being(-1.392 4±3.670 9)mm vs(-0.816 5±2.670 5)mm,(0.969 7±4.076 1)mm vs(0.418 2±2.911 4)mm, and(0.704 4±1.805 6)mm vs(0.471 7±1.641 3)mm respectively;the extending margin had the values being 7 mm vs 5 mm, 6 mm vs 4 mm, and 4 mm vs 3 mm respectively.Conclusion EPID ensures the correctness and accuracy in postoperative intensity modulated radiotherapy of rectal cancer,which makes target area gifted with maximized dose,the surrounding tissue and organs at risk protected adequately,and provides theoretical support for extending CTV margin.[Chinese Medical Equip-ment Journal,2018,39(5):59-63]

Factors of anastomotic fistula after low rectal cancer resection / 肿瘤研究与临床

Surgical therapy should be the main method in treatment of rectal cancer.Along with the increase rate of undergoing anterior resection for rectal cancer,it is getting be paid more and more attention on postoperative anastomotic fistula as the main complications of rectal carcinoma.In recent research,anastomotic fistula occurred caused by various factors had also been put forward gradually,while the risk factors for postoperative anastomotic fistula were still remain unclear.Therefore,it is very important to understanding the risk factors in order to prevent the happening of the anastomotic fistula,and provide clinical basis for their necessary preventive colostomy.