Application Of Intensity Modulated Radiotherapy In The Treatment Of Pancreatic Cancer And Cervical Cancer

Objective We analyzed the differences between the fixed field intensity modulated radiotherapy (FF-IMRT) and volumetric modulated arc therapy (VMAT) in treatment planning for pancreatic carcinoma.Methods 10 patients with pancreatic carcinoma were selected for the comparison. Plans of FF-IMRT and VMAT were developed on the same CT image of each patient respectively. The prescription was 50Gy in 25 fractions. The dose-volume histograms (DVH)-based parameters of planning target volume (PTV), organs at risk(OARs) and normal tissue were evaluated. We also analyzed the monitor units (MU) and delivery time of different plans.Results All parameters on target between the FF-IMRT and VMAT plans were statistically respectively similar. Compared to FF-IMRT, VMAT plans increased the V5 of liver, stomach, small bowel and body significantly. And V10 and V20 of the liver, V10, V20, V50 of the small bowel, V20 of the left kidney,V30, Dmean, Dmax of the right kidney, and V10,V20,Dmax of the body were observed for a various dose level with reductions. On the spinal cord, the Dmax was decreased by 1.85Gy in VMAT plans. In addition, the VMAT allowed a reduction of 126.9Gy (20.48%) for monitor units, compared with FF-IMRT.Conclusion For patients with pancreatic carcinoma, VMAT provided reduced monitor units and delivery time while the dosimetric parameters were similar or improved in planning level.Purpose To evaluate the treatment outcome and toxicity for stage ⅡB cervical cancer patients treated by definitive intensity-modulated radiation therapy(IMRT) and concurrent chemotherapy, and to identify the prognostic factors.Methods A total of 368 patents with stage ⅡB cervical cancer were treated with definitive IMRT and cisplatin-based concurrent chemotherapy, plus brachytherapy between May 2005 and December 2013 in Peking Union Medical College Hospital. All patents received external beam irradiation of 50.4Gy/28fraction with IMRT technology, and a concomitant boost to 59-60Gy/28fraction was delivered to involved lymph nodes. High dose rate(HDR) brachytherapy was prescribed to point A from the the third week of external beam irradiation. Patients received weekly cisplatin of 40mg/m2.Results The median follow-up time was 33.9 months (rang 5.6-114.6).3-year overall survival rate (OS), disease free survival rate (DFS) and local control rate (LC) were 88.5%、83.4%、93.9%, respectively. The 5-year OS, DFS and LC were 86.0%, 82.8%、93.9%. Para-aortic lymph node metastasis was the independent prognostic factor of OS. Tumor size, para-aortic lymph node metastasis and squamous cell carcinoma antigen (SCC Ag) level were independent predictors of DFS.There was no treatment related death in this study.42 (20.0%) patients and 94 patients (44.8%) developed grade 3 or greater genitourinary(GU) complications and gastrointestinal(GI) complications. The grade 3 or greater late GU and GI complication rate for all patients was 2.5%(7 patients) and 2.8%(8 patients)Conclusion Good treatment outcomes and toxicity were achieved with IMRT and concurrent chemotherapy for patients with stage ⅡB cervical cancer. Para-aortic lymph node metastasis, large tumor and high SCC Ag level intend to result a worse survival.Purpose To evaluate the treatment outcome and toxicity for stage ⅡB cervical cancer patients treated by radiotherapy, and to identify the prognostic factors.Methods A total of 478 patents with stage ⅡB cervical cancer were treated with definitive radiotherapy and cisplatin-based concurrent chemotherapy, plus brachytherapy between January 2001 and December 2013 in Peking Union Medical College Hospital. External beam radiation therapy technique is 3-dimensional conformal radiation therapy (3D-CRT) or intensity modulated radiation therapy (IMRT).50Gy/25fraction was delivered to the whole pelvis with 4-field box technique for patients treated with 3D-CRT. The other patents received external beam irradiation of 50.4Gy/28fraction with IMRT technique, and a concomitant boost to 59-60Gy/28fraction was delivered to involved lymph nodes. High dose rate(HDR) brachytherapy was prescribed to point A from the the third week of external beam irradiation. Patients received weekly cisplatin of 40mg/m2.Results The median follow-up time was 33.9 months (rang 2.4-183.3).3-year overall survival rate (OS), disease free survival rate (DFS) and local control rate (LC) were 86.1%、81.6%、92.4%, respectively. The 5-year OS, DFS and LC were 82.6%、 80.8%、92.0%, respectively. Para-aortic lymph node metastasis was the independent prognostic factor of OS(p=0.000) and DFS(p=0.000). The EQD2 of A point total dose was the independent prognostic factor of OS(p=0.006) and DFS(0.029). Tumor size is the prognostic factor of LC(p=0.045). The grade 3 or greater late GI and GU complication rate for all patients was 3.0% and 3.0%, respectively.Conclusion Good treatment outcomes was achieved with chemoradiotherapy for patients with stage ⅡB cervical cancer in our institute,and the severe complication rate was low. Para-aortic lymph node metastasis, low A point dose and large tumor intend to result a worse survival.