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Objective To evaluate the geometric and dosimetric accuracy of autosegmentation software for contouring the organ-at-risk ( OAR) of esophageal cancer, and discuss its clinical feasibility. Methods A total of 10 patients were enrolled, and single and multi-template were adopted respectively to auto-delineate corresponding OARs on target CT images based on image registration. The geometric consistency including volume difference (ΔV) , dice similarity ( DSC) and position difference (Δx, Δy,Δz) between the two autosegmentation method and manual were compared using Wilcoxon signed-rank test. And the correlation between DSC and OAR volume was analyzed. In addition, to evaluate the clinical feasibility of autosegmentation, the dose distributions of all OARs were compared using Friedman test. Results The average DSC of all OARs obtained by single and multi-template were 0.82 ± 0.17 and 0.92 ± 0.54, respectively, with statistically significant difference (Z= -2.803- -2.497, P<0.05). A positive correlation between DSC of the autosegmentation and OAR volume was found by spearman analysis, and the single-template was not good enough for the spinal cord with smaller volume. The positional deviations of multi-template group were less than 0.5 cm in three directions, which were better than single-template group. The main dosimetric indexes of single-template and multiple-template were similar to manual coutours. V20 of whole lung were 23.2％, 22.4％ and 22.1％, Dmeanof whole lung were (11.3 ±4.0), (11.1 ±4.5) and (11.0 ±4.3) Gy, Dmaxof spinal cord were (40.3 ±4.8), (38.2 ±6.7) and (39.4 ± 5.3) Gy, respectively, and V30 of heart were 16.0％, 15.8％ and 15.5％, respectively. There was no statistical difference between the three methods (P>0.05), and all of the dosimetric indexes were in line with the requirements of clinical dose limits. Conclusions The autosegmentation software can achieve satisfactory precision for the OARs of the esophageal cancer patients, and the multi-template method is better than the single-template, which is more suitable for clinical application.
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Objective To explore the clinical and imaging factors influencing the patients' prognosis after preoperative radiotherapy for local advanced rectal cancer.Methods We retrospectively analyzed 106 locally advanced rectal cancer patients from June 2004 to September 2015 in our institution.All patients underwent preoperative radiotherapy.According to the Mandard score,patients were divided into 5 groups (TRG1-5).All patients were divided into two groups according to the TRG,which including good responder (TRG1 + 2) and poor responder (TRG3 + 4 + 5) groups.All of the tumor ADC values of post-RT were measured by Diffusion-weighted MRI technology,and the relationship between tumor ADC values of post-RT and TRG was analyzed.Results In univariate analysis,age,chemotherapy,pT,pN,differentiation degree,vascular invasion and TRG were significantly associated with overall survival (x2 =3.945-8.110,P ＜ 0.05).Multivariate analysis indicated that differentiation degree and TRG were the independent prognostic factors for OS (x2 =5.221,6.563,P ＜ 0.05).No significant difference was found between long-course and short-course radiotherapy group (P ＞ 0.05) in OS.The good responder group had a favorable survival in 5-year OS compared to the poor responder group (x2 =8.110,P ＜ 0.05).Preoperative radiotherapy,preoperative chemotherapy,pathological type,differentiation degree and gross type,vascular tumor thrombus and tumor ADC values of post-RT were significantly associated with TRG (x2 =4.189-18.139,P ＜ 0.05).The best critical point of tumor ADC values of post-RT was 1.7 x 10-3 mm2/s by using ROC curve.The accuracy of tumor ADC values of post-RT in predicting TRG1 + 2 was 70％.Conclusions The TRG can predict the efficacy of preoperative radiotherapy in patients with locally advanced rectal cancer based on the Mandard score.There was no significant difference in OS between long-course radiotherapy group and short-course radiotherapy group.The tumor ADC values of post-RT might become a potential factor to predict TRG in patients with locally advanced rectal cancer after preoperative radiotherapy.
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Objective To evaluate the potential influencing factors associated with pathologic complete response ( pCR) after neoadjuvant chemoradiotherapy for locally advanced rectal cancer ( LARC) . Methods A retrospective analysis was performed on the clinical data 265 patients with stageⅡandⅢ( the 7th version of AJCC) rectal cancer admitted to our hospital from 2011 to 2013. All patients underwent neoadjuvant concurrent chemoradiotherapy ( CCRT ) followed by surgery with/or without induction chemotherapy during the interval between the complete of CCRT and surgery. The predictors associated with pCR were analyzed by univariate and multivariate logistic regression analyses. With the use of the independent predictive variables for pCR from multivariate analysis, a clinical risk score model was established according to the following criteria:no?risk group (0 factor);low?risk group (1 factor);high?risk group ( 2 factors) . Results Among these 265 patients, 50( 18. 9%) achieved pCR. The univariate analysis showed that carcinoembryonic antigen ( CEA) level before CCRT ( P=0. 017) , T stage before CCRT ( P=0. 001), interval between complete of CCRT and surgery (P=0. 000), and the maximum tumor thickness before CCRT ( P=0. 040) were significantly associated with pCR. The multivariate analysis showed that pre?CCRT CEA level ( P=0. 021 or 0. 446) and interval between the complete of CCRT and surgery ( P=0. 000 or 3. 774) were significant predictors of pCR. When stratifying for smoking status, only low pre?CCRT CEA level was significantly associated with pCR in the non?smoking patients ( P=0. 044) . For the prediction of pCR by the clinical risk score model, the sensitivity was 0. 805, the specificity was 0. 460, the area under the receiver operating curve was 0. 690 ( 95% CI= 0. 613?0. 767 ) , the positive predictive value was 35 . 4 9%, the negative predictive value was 8 6 . 5%, and the predictive accuracy was 7 3 . 9%. Conclusions For locally advanced rectal cancer, pCR can be achieved in some patients after neoadjuvant therapy. Low pre?CCRT CEA level and long interval time between CCRT and surgery are independent factors associated with pCR, and only low pre?CCRT CEA level is an associated factor in the group of nonsmokers. The clinical risk score model based on pre?CCRT CEA level>5 ng/ml and time interval from CCRT completion to surgery≤8 weeks can be used to predict pCR after neoadjuvant chemoradiotherapy for LARC.
ABSTRACT
Extrahepatic biliary system cancer(EBSC)is an uncommon disease with a poor prognosis. There is no change to making radical resection in most patients because most of the diseases are diagnosed at late stage.Chemoradiotherapy has been a major therapeutic modality of EBSC.In recent year,the progress of chemoradiotherapy has been made in management of resectable and unresectable EBSC.