1.Pertinence analysis of intensity-modulated radiation therapy dosimetry error and parameters of beams
Zifeng CHI ; Dan LIU ; Yankun GAO ; Runxiao LI ; Chun HAN
Chinese Journal of Radiological Medicine and Protection 2012;32(3):294-296
Objective To study the relationship between parameter settings in the intensity-modulated radiation therapy (IMRT) planning in order to explore the effect of parameters on absolute dose verification.Methods Forty-three esophageal carcinoma cases were optimized with Pinnacle 7.6c by experienced physicist using appropriate optimization parameters and dose constraints with a number of iterations to meet the clinical acceptance criteria.The plans were copied to water-phantem,0.13 cc ion Farmer chamber and DOSE1 dosimeter was used to measure the absolute dose.The statistical data of the parameters of beams for the 43 cases were collected,and the relationships among them were analyzed.The statistical data of the dosimetry error were collected,and comparative analysis was made for the relation between the parameters of beams and ion chamber absolute dose verification results.Results The parameters of beams were correlated among each other.Obvious affiliation existed between the dose accuracy and parameter settings.When the beam segment number of IMRT plan was more than 80,the dose deviation would be greater than 3% ; however,if the beam segment number was less than 80,the dose deviation was smaller than 3%.When the beam segment number was more than 100,part of the dose deviation of this plan was greater than 4%.On the contrary,if the beam segment number was less than 100,the dose deviation was smaller than 4% definitely.Conclusions In order to decrease the absolute dose verification error,less beam angles and less beam segments are needed and the beam segment number should be controlled within the range of 80.
2.Comparison of infrared mrker-based positioning system and electronic portal imaging device for the measurement of setup errors
Yankun CAO ; Chao GAO ; Lan WANG ; Zifeng CHI ; Chun HAN
Chinese Journal of Radiation Oncology 2011;20(5):414-416
ObjectiveTo measure the setup errors with infrared marker-based positioning system (IM-BPS) and electronic portal imaging device (EPID) for patients with esophageal carcinoma and lung cancer and investigate the accuracy and practicality of IM-BPS. MethodsFrom January 2007 to January 2008, 40 patients with esophageal carcinoma and 27 patients with lung cancer received three-dimensional conformal radiotherapy or intensity-modulated radiotherapy, setup errors during the treatment were measured with IM-BPS and EPID, and the data of setup errors were compared with paired t-test and agreement with x2-test. ResultsIt takes 10 - 12 mins to complete the validating for each patient by EPID) system, while IMBPS system only needs 2 -5 mins. The mean setup errors along x, y and z-axis for patients with esophageal carcinoma measured by IM-BPS and EPID were 3.49 mm, 3. 19 mm, 3.31 mm and 4. 03 mm, 3.41 mm, 3.43 mm, respectively. For the patients with lung cancer, the setup errors were 4. 23 mm, 3.51 mm, 3. 39mm and 4. 85 mm, 3. 53 mm, 3.74 mm, respectively. The difference of setup errors meanured by the two systems was within 1 mm for 65% esophageal carcinoma patients ( x2 =51.09, P =0. 000), and 55% lung cancer patients ( x2 =53. 35, P =0. 000).Conclusions The measurement results of setup errors for patients with esophageal carcinoma and lung cancer show that IM-BPS is mostly better than EPID. Though validating for patients can be measured accurately and be well quality controlled, IM-BPS is used easily because of macroscopic, homely,spare time and real-time monitoring.
3.Evaluation of IMRT plans of prostate carcinoma from four treatment planning systems based on Monte Carlo
Zifeng CHI ; Chun HAN ; Dan LIU ; Yankun CA ; Runxiao LI
Chinese Journal of Radiation Oncology 2011;20(3):222-225
Objective With the Monte Carlo method to recaleulate the IMRT dose distributions from four TPS to provide a platform for independent comparison and evaluation of the plan quality.These results wiU help make a clinical decision as which TPS will be used for prostate IMRT planning.Methods Eleven prostate cancer cases were planned with the Corvus,Xio,Pinnacle and Eclipse TPS.The plans were recalculated bv Monte Cado using leaf sequences and MUs for individual plans.Dose-volume-histograms and isodose distributions were compared.Other quantities such as Dmin(the minimum dose received by 99% of CTV/PTV),Dmax(the maximum dose received by 1%of CTV/PTV),V110%,V105%,V95%(the volume of CTV/PTV receiving 110%,105%.95% of the prescription dose),the volume of rectum and bladder receiving>65 Gy and>40 Gy,and the volume of femur receiving>50 Gy were evaluated.Total segments and MUs were also compared.Results The Monte Carlo results agreed with the dose distributions from the TPS to within 3%/3 mm.The Xio,Pinnacle and Eclipse plans show less target dose heterogeneity and lower V65 and V40 for the rectum and bladder compared to the Corvus plans.The PTV Dmin is about 2 Gy lower for Xio plans than others while the Corvus plans have slightly lower female head V50(0.03%and 0.58%)than others.The Corvus plans require significantly most segments(187.8)and MUs(1264.7)to deliver and the Pinnacle plans require fewest segments(82.4)and MUs(703.6).Conclusions We have tested an independent Monte Carlo dose catculation system for dose reconstruction and plan evaluation.This system provides a platform for the fair comparison and evaluation of treatment plans to facilitate clinical decision making in selecting a TPS and beam delivery system for particular treatment sites.
4.Investigation of dose verification of esophageal carcinoma intensity modulated radiotherapy
Dan LIU ; Zifeng CHI ; Wei ZHANG ; Lan WANG ; Chun HAN
Chinese Journal of Radiation Oncology 2011;20(1):64-68
Objective To compare the results of three dose verification solutions of esophageal carcinoma IMRT plans. Methods Seven esophageal carcinoma cases were planned with Pinnacle 8.0 h.The MATRIXX and Delta4 were chosen as the two-dimensional dosimetry and three-dimensional dosimetry.IMRT plans and Delta4 phantom plans were also recalculated by Monte Carlo. Gamma values were evaluated for MATRIXX and Delta4 with 3 mm/3% gamma criteria. For the comparison of Pinnacle, Delta4 and Monte gamma maps, the dose distribution in central plane, dose profiles and dose-volume histograms were used to evaluate the agreement. Results The gamma maps comparison show that with 3 mm/3% gamma criteria an over 98% pass ratio was obtained by MATRIXX measurement. A 94. 4% gamma pass ratio whicl.contains 4 fields gamma pass ratio lower than 90%, was obtained by Delta4 measurement. A 97.6% and 99. 8% gamma pass ratio was obtained between the Delta4 measurement and Monte Carlo simulation with 2 mm/2% and 3 mm/3% gamma criteria. The dose distribution in central plane and dose profiles from Pinnacle calculation were almost in agreement with both the Monte Carlo simulation and Delta4 measurement. The DVH plot have slightly differences between Pinnacle and Delta4 measurement as well as Pinnacle and Monte Carlo simulation, but have excellent agreement between Delta4 measurement and Monte Carlo simulation. Conclusions It was shown that all the three methods can be used very efficiently to verify esophageal carcinoma IMRT delivery, Delta4 and Monte Carlo simulation no data missed. The primary advantage of Delta4 is the fact it can measure true 3D dosimetry while Monte Carlo can simulate in patients CT images but not in phantom.
5.Impact of setup errors on dose distribution of three dimensional conformal radiotherapy for patients with esophageal carcinoma
Chao GAO ; Lan WANG ; Zifeng CHI ; Chun HAN ; Jun WANG ; Xin ZHANG ; Guoxin MA ; Aiqin XIAO
Chinese Journal of Radiation Oncology 2009;18(4):270-273
Objective To measure the setup errors of patients with esophageal carcinoma during the treatment of three dimensional conformal radiotherapy (3DCRT), and to analyze the impact of setup errors on dose distribution of GTV,CTV and normal tissues around. Methods Forty-two patients with esophageal cancer treated by 3DCRT were included. The setup errors of each patient were measured once a week for 6 times by electronic portal imaging device (EPID). The setup errors were integrated into the treatment plan-ning system by moving the isocenter. Then the dose distribution of GTV, CTV and normal tissues were recal-culated. Results The systematic setup errors of the 42 patients were - 2.31 mm, - 0.55 mm and - 0.16 mm, and the random errors were 4.42 mm, 4.35 mm and 4.48 mm in the directions of lef-fight, anterior-posterior,and superior-inferior, respectively. The dose covered 95% GTV( D95 ) was reduced by 32 cGy and by 88 cGy for CTV D95. The lung V20 in the original plan and the integrated plan was 22.49% and 22.02%, respectively. The average dose of the heart in the two plans was 2077.62 cGy and 2036.23 cGy, respectively. In the original plan, no patient had maximum dose of spinal cord over 4500 cGy; While in the intergrated plan there were 18 patients had the spinal cord dose more than 4500 cGy, with a maximum dose of 5503.90 cGy. Conclusions The setup errors cause significant dose reduction of GTV and CTV, but not of the lung and heart . The maximum dose of the spinal cord may exceed 4500 cGy due to the setup errors.
6.An Untargeted Urinary Metabolomics Strategy for Investigation of Therapeutical Mechanism of Schisandra chinensis on Complications of Diabetes Rats
Hongxiang HAN ; Fengrui SONG ; Zhenbo SHU ; Zhiqiang LIU ; Yueying REN ; Zifeng PI
Chinese Journal of Analytical Chemistry 2017;45(3):389-396
An untargeted urinary metabonomics method based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry ( UPLC-Q-TOF-MS ) has been established to investigate the mechanism of Schisandra chinensis in treating diabetes and its complications. The urinary biomarkers related to the therapeutic effects of Schisandra chinensis on the diabetes rats were analyzed. In urine, 28 kinds of endogenous metabolites were identified as potential biomarkers, including 13 endogenous metabolites in positive ion mode, 15 endogenous metabolites in negative ion mode, and hippuric acid detected both in positive and negative ion modes. The results revealed that Schisandra chinensis mainly affected the pathways of pentose and glucuronate interconversions, riboflavin metabolism, pantothenate and CoA biosynthesis, arginine and proline metabolism, intestinal bacteria metabolism, ascorbate and aldarate metabolism and tryptophan metabolism in diabetic rats. Combined with biological analysis of these pathways, the therapeutic mechanism of Schisandra chinensis on diabetes and its complications was verified. Based on the biological function of each pathway, the effect of Schisandra chinensis on diabetic nephropathy is stronger. Moreover, it also has the effects of protecting liver, decreasing fat and antioxidant activity.
7.The expressions and clinical significances of HOXB1 and miR-3175 in human glioma
Haixia ZHOU ; Liang HAN ; Zifeng ZHU ; Jun WEI ; Yu TIAN ; Zhaohui LI
Journal of International Oncology 2016;43(11):817-821
Objective To explore the relationship and the clinical significance of homeobox gene B1 (HOXB1 )and microRNA-31 75 (miR-31 75)expressions in human glioma.Methods The expression levels of HOXB1 and miR-31 75 in 60 glioma tissues and 1 5 normal brain tissues were analyzed by real-time fluores-cent quantitative PCR (qRT-PCR).Spearman rank correlation analysis was performed to explore the relation-ship between HOXB1 and miR-31 75 in human glioma tissues.The relationship between HOXB1 (or miR-31 75)and clinical pathological characteristics of glioma patients was analyzed.The correlation of HOXB1 (or miR-31 75)and survival rate was calculated by Kaplan-Meier.And COX regression models were used to assess the prognostic factors.Results Compared with normal brain tissues,the expression of HOXB1 was significant-ly decreased in glioma tissues (1 .498 ±0.323 vs.0.946 ±0.588,t =-5.680,P =0.000);and the expre-ssion of miR-31 75 was obviously increased in glioma tissues (1 .008 ±0.355 vs.2.076 ±0.841 ,t =4.274, P =0.000),and HOXB1 expression was negatively correlated with miR-31 75 expression in glioma tissues (r =-0.601 ,P =0.000).HOXB1 expression was related with histologic grade (χ2 =4.848,P =0.028), and miR-31 75 expression was related with histologic grade (χ2 =5.640,P =0.01 8)and Karnofsky score (χ2 =4.785,P =0.029).The results of Kaplan-Meier revealed that there were significant differences in median survival time between HOXB1 (or miR-31 75)high-expression group and HOXB1 (or miR-31 75)low-expression group [HOXB1 :(21 .0 ±4.0)months vs.(7.0 ±0.8)months;χ2 =7.495,P =0.006;miR-31 75:(6.0 ±0.6)months vs.(1 6.0 ±5.8)months;χ2 =9.591 ,P =0.002].COX regression models showed that tumor degree (RR =6.556,95% CI:1 .1 96-35.952,P =0.002),HOXB1 (RR =0.01 8, 95%CI:0.001 -0.31 2,P =0.006)and miR-31 75 (RR =2.098,95%CI:1 .663-7.51 3,P =0.037)were independent prognostic factors for prognosis.Conclusion The HOXB1 expression may be negatively correlated with miR-31 75 in human glioma tissues,and the expression levels of HOXB1 and miR-31 75 are associated with the glioma malignant degree,survival time and prognosis of glioma patients.
8.Para-recurrent lymph node metastasis was a significant predictor for cervical lymph nodes metastasis in thoracic esophageal carcinoma
Chenglin LI ; Yadi WANG ; Chun HAN ; Yunjie CHENG ; Zifeng CHI ; Guogui SUN ; Fuli ZHANG ; Qing LIU
Chinese Journal of Radiation Oncology 2012;21(4):340-342
ObjectiveTo evaluate correlation factors of cervical lymph nodes metastasis in thoracic esophageal carcinoma.MethodsLocal-regional metastasis of lymph node for 126 cases with esophageal squamous cell cancer after surgery from 2004 to 2009 were reviewed.Risk factors of cervical lymph nodes metastasis were examined by multiple Logistic regression analysis.ResultsIn 126 cases,supraclavicular lymph node metastasis rate was 43.7% (55/126).By logistic regression,none of the primary site,T stage,N stage,histological grade,lymph node metastasis rate,lymph node metastasis degree and number of lymph nodes metastatic field was not the high risk of cervical lymph nodes metastasis.In addition,multivariate analysis found that lymph node metastasis in mediastinum region 1 was high risk factor for lymph node metastasis of region 1 ( x2 =12.14,9.27,P =0.000,0.002),lymph node metastasis in region Ⅲ and region 2 were high risk factors for lymph node metastasis of region Ⅱa ( x2 =14.56,8.27,8.02,3.93,P =0.000,0.004,0.005,0.047 ).ConclusionMediastinal para-recurrent nerve lymph node metastasis is a significant predictor for cervical lymph nodes metastasis.
9.Comparison of dose distribufions between conformal and intensity-modulated radiotherapy for the upper esophageal carcinoma
Jun WANG ; Shuchai ZHU ; Chun HAN ; Zifeng CHI ; Dan LIU ; Runxiao LI
Chinese Journal of Radiation Oncology 2008;17(4):275-279
Objective To evaluate the optimized conformal and IMRT plans for the upper esophageal carcinoma. Methods Eight patients with upper esophageal carcinoma underwent CT simulation.GTV was contoured on the CT image,referring the esophagogram and endoscopy simuhaneously,then CTV and PTV were also defined using the same criteria.Different conformal radiotherapy plans consisting of 3 fields(F),4F or 6F,IMRT plans consisting of 3F,4F,5F,7F,9F or 11F,and a simplified IMRT(s-IMRT)plan were designed for these patients.The minimum prescription dose that 95%of PTV volume received was 6000 cGy.Dose distributions of the PTV and OARs in different 3 DCRT and IMRT plans were compared and the optimized plans for the upper esophageal carcinoma were then recommended. Resuits Dose and volume parameters of PTV were similar among the 3DCRT plans(P>0.05).4F 3DCRT plan reduced lung V20 as compared to 6F plan(P<0.05),and mean lung dose(MLD)of 3F and 6F 3DCRT plans were higher than that of4F plan(P<0.05).PTV D100 of 3F IMRT plan was lower than that of 9F and 11F plans(P<0.05).IV of 4F IMRT plan was larger than that of 9F and 11F IMRT plans(P<0.05).PTV dose and volume parameters of the 9F IMRT and 1 1 F IMRT were similar comparing with 5F.7F and s-IMRT plans,and OARs dose was also similar among IMRT plans(P>0.05).PTV CI,D100,D95,V100 and V95 of the 4F 3DCRT plan were all lower than those of 5F,7F and s-IMRT plans(P<0.05).5F,7F and s-IMRT plans reduced lung V20 as compared to 4F 3DCRT plan(P<0.05).Conclusions For the upper esophageal carcinoma.4F 3DCRT plan is recommended among the 3DCRT plans.5F.7F and s-IMRT plans are recommended among the IMRT plans,which are superior than 4F 3 DCRT plan.
10.Compare the tumor length in CT images with the real length calculated from surgical specimen in esophageal carcinoma
Jun WANG ; Chun HAN ; Shuchai ZHU ; Xin ZHANG ; Zifeng CHI ; Ying LI
Chinese Journal of Radiation Oncology 2008;17(2):93-96
Objective To evaluate the variance and the concordance between the tumor length measured by CT scans and that measured by surgical specimens in esophageal carcinoma. Methods Fiftytwo surgical specimens of the esophageal carcinoma were made into pathological giant section.The shrinkage ratio of tumor was calculated by comparing the length of the specimen fixed by formalin for 24 h and that measured during the operation.One hundred and thirty-seven patients with esophageal carcinoma underwent spiral CT scan before the surgery,and the length of the gross tumor volume was obtained.After the tumor length of the fixed specimen had been measured,the real tumor length in situ was calculated using the shrinkage ratio.Then the variance and the concordance between the tumor length in CT scans and that in situ were compared.Results The mean shrinkage ratio was 90%±10%.The mean tumor length in CT scans was longer than that in situ(5.8 am±2.4 cm vs 4.1 cm±1.8 cm,P=9.68,P=0.000).The concordance of the length measured by the two methods was 40.9%(56/137). Conclusions A certain variance existed between the tumor length in CT images and that computed from surgical specimen in esophageal carcinoma.The results of esophagography and endoscopy should also be referred to delineate the gross tumor volume of esophageal carcinoma.