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Objective To compare the clinical efficacy between simultaneous integrated boost (SIB) and sequential boost (SB) using intensity-modulated radiotherapy (IMRT),and investigate the long-term clinical efficacy and adverse events of SIB-IMRT in combination with chemotherapy in the treatment of esophageal cancer.Methods Clinical data of 330 patients diagnosed with esophageal cancer undergoing radical chemoradiotherapy in Fourth Hospital of Hebei University from January 2006 to December 2015 were respectively analyzed.All patients were assigned into the SIB-IMRT (n=135) and SB-IMRT groups (n=195).All patients received definitive radiotherapy with elective nodal irradiation (ENI).After the propensity score matching (PSM),105 patients were enrolled in each group.Kaplan-Meier method was used to survival analysis.Cox model was used to multivariate prognostic analysis.Results Prior to PSM,the 1-,3-and 5-year local control rates were 80.1％,58.3％,46.7％ and 72.1％,44.9％,40.5％ in the SIB-IMRT and SB-IMRT groups (P=0.050),and the 1-,3-and 5-year OS rates were 81.4％,51.9％,43.5％ and 80.5％,37.9％,22.3％(P=0.014),respectively.After the PSM,the 1-,3-and 5-year LC rates were 80.2％,54.2％,43.9％ and 75.5％,47.2％,41.2％ (P=0.264),and the 1-,3-and 5-year OS rates were 78.9％,49.0％,40.8％ and 83.3％,41.7％,24.8％ (P=0.265),respectively.Multivariate analysis demonstrated that TNM staging was an independent prognostic factor in the SIB-IMRT group,whereas TNM staging and chemotherapy served as the independent prognostic factors in the SB-IMRT group.Stratified analysis revealed that the LC rate in the SIB-IMRT was significantly higher than that in the SB-IMRT group when radiotherapy alone was performed (P =0.018).The OS rate in the SIB-IMRT group was equally higher compared with that in the SBIMRT group.Conclusions The LC and OS rates are almost identical after SB-IMRT and SIB-IMRT in the treatment of esophageal cancer,whereas the prognostic survival in the SIB-IMRT group is significantly longer compared with that in the SB-IMRT group during radiotherapy alone.The findings remain to be validated by multi-center investigations with a large sample size.
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Objective To investigate the dosimetric comparison of target volumes and organs at risk (OAR) between volumetric-modulated arc therapy (VMAT) and intensity-modulated radiotherapy (IMRT) for esophageal cancer by a meta-analysis.Methods A literature search was performed to collect the clinical studies on dosimetric comparison between VMAT and IMRT.The primary endpoints of interest were dosimetric parameters of target volumes and OAR, number of monitor units (MUs), and treatment time (TT).Results A total of 17 studies involving 323 patients were included in this meta-analysis.When the total dose was>50.4 Gy, VMAT showed significantly lower mean dose (Dmean) of gross tumor volume (GTV) and maximum dose (Dmax) of planning target volume (PTV) than IMRT (P=0.009;P=0.039).There were no significant differences in Dmean, V30, and V40 of the heart, Dmax of the spinal cord, and V5, V10, and Dmean of the lung between VMAT and IMRT (P>0.05).VMAT showed significantly lower V15, V20, and V30 of the lung than IMRT (P=0.001;P=0.000;P=0.023).When the single dose was 1.8 Gy and 2.0 Gy, VMAT showed significantly lower TT (reduced by 323.5 s and 193.7 s) and number of MUs (reduced by 275.4 MU and 134.2 MU) than IMRT (P=0.000 and 0.009;P=0.000 and 0.022).Conclusions VMAT can significantly reduce TT, MUs, irradiation dose to the lung, and the risk of radiation pneumonitis, and improve the utilization rate of equipment.Compared with IMRT, VMAT has no significant advantages in protection of the spinal cord and the heart and dosimetric parameters of target volumes except Dmean of PTV and Dmean and Dmax of GTV when the total dose was ≤50.4 Gy.
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Objective To analyze the prognosis of advanced esophageal carcinoma treated with paclitaxel and different platinum?based chemotherapy regimens plus intensity?modulated radiotherapy ( IMRT) , and to explore an optimal chemotherapy regimen. Methods A total of 242 patients with advanced esophageal carcinoma who were admitted to our hospital and treated with paclitaxel and cisplatin ( 68 patients), nedaplatin (85 patients), lobaplatin (58 patients), or oxaliplatin (31 patients) plus IMRT from 2008 to 2014 were enrolled as subjects. The prognosis of the four groups was analyzed after 2, 3, and ≥4 cycles of chemotherapy. The survival rates were calculated by the Kaplan?Meier method and analyzed by the log?rank test. The Cox model was used for the multivariate prognostic analysis. Results The sample number of 3 years was 168 cases. In all the 242 patients, the medium survival time was 31. 1 months and the 3?year overall survival ( OS) rate was 47. 4%. There was no significant difference in the 3?year OS rate between the cispaltin, nedaplatin, lobaplatin, and oxaliplatin groups ( 46. 2% vs. 56. 4% vs. 45. 7% vs. 29. 0%, P=0. 090) . The stratified analysis showed that the cisplatin, nedaplatin, and lobaplatin groups had a significantly higher OS rate than the oxaliplatin group ( 50. 1% vs. 29. 0%, P=0. 021 ) . There was no significant difference in the 3?year OS rate between patients receiving 2, 3, and≥4 cycles of chemotherapy ( 40. 1% vs. 49. 5% vs. 50. 8%, P=0. 264) . The multivariate analysis showed that esophageal tumor volume and the maximal size of metastatic lymph node were independent prognostic factors. Conclusions Combined with IMRT, paclitaxel plus cisplatin, nedaplatin, or lobaplatin?based chemotherapy achieves improved survival rates than paclitaxel plus oxaliplatin?based chemotherapy. Esophageal tumor volume and the maximal size of metastatic lymph node are independent prognostic factors.
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Objective To evaluate the incidence of and risk factors for esophageal fistula and fatal bleeding after intensity?modulated radiotherapy ( IMRT) for esophageal cancer. Methods Clinical data were collected from 128 patients with esophageal cancer who received radical IMRT in our hospital from January 2012 to December 2014. According to the incidence of esophageal fistula and fatal bleeding, those patients were divided into control group ( n= 105 ) and severe complications group ( n= 23 ) . In the severe complications group,12 patients had esophageal fistula and 11 fatal bleeding. Between?group comparison was made by χ2 test. The Cox model was used for the multivariate analysis. Results Chest and back pain in the initial diagnosis,clinical stage cT4 ,tumor type ( ulcerative) ,gross tumor volume ( GTV)>50 cm3 ,and GTV maximum diameter>2?45 cm were risk factors for esophageal fistula and fatal bleeding after radiotherapy for esophageal cancer (P=0?042,0?042,0?019,0?046,0?002).The multivariate analysis showed that tumor type ( ulcerative) and GTV maximum diameter were independent risk factors for esophageal fistula and fatal bleeding ( P=0?010,HR=0?329,95% CI:0?142?0?763;P=0?009,HR=3?805,95% CI:1?404?10?312) . Conclusions The efficacy of IMRT is severely restricted by the incidence of esophageal fistula and fatal bleeding. For patients with an ulcerative type of esophageal cancer or a GTV max diameter of>2?45 cm,the chemoradiotherapy plan should be optimized to reduce the risk of severe complications.
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Objective To compare the dosimetric difference between volumetric modulated arc therapy (VMAT) and static intensity modulated radiotherapy (IMRT) for esophageal carcinoma.Methods Thirty patients were selected in this study,including 5 cases in the cervical,5 the lower thorax,10 the upper thorax and 10 the middle thorax.VMAT plans with a single arc and IMRT plans with five fields designed for each patients.Planning target volume (PTV) were prescribed to 60 Gy in 30 fractions.Delta 4 was used to verifie the dosimetric of treatment plans.Using paired t-test or Wilcoxon signed-test to compare the dose distribution on planning and organs at risk (OAR).The monitor units and treatment time were also evaluated to measure the treatment efficiency.Results All the VMAT and IMRT plans can satisfy the clinical dosimetry requirements.VMAT had better conformal index for PTV than IMRT (P =0.008).VMAT was better than IMRT by reducing the Dmax of spinal cord (P =0.032),while the V30,V40 and Dmean of heart were significantly higher (P =0.041,0.012,0.002).For cervicals,the V5,V10,V15 and mean dose of lung were significant higher in VMAT than those in IMRT (P =0.002-O.002,0.002).For uppers,the values of heart V30 and Dmean were significantly larger in VMAT than IMRT (P =0.030,0.026).However,the Dmax of spinal cord in VMAT was lower than IMRT (P =0.006).For middles,VMAT reduced V10,V15,V20 of lung (P =0.015,0.028,0.041).There were no significant differences between VMAT and IMRT in the lowers (P =0.262-0.998).The 3 mm/3％ γ pass rate was 92.75％ for VMAT and 92.98％ for IMRT (P =0.826).The average MU of VMAT (460.66 MU) was reduced by 11.84％ compared with IMRT (522.55 MU) (P=0.001).The delivery time of VMAT (139.6s) compared with IMRT (298.73 s) was reduced by an average of 53.27％ (P =0.000).Conclusions Compared with IMRT,VMAT improved the OARs dose sparing and the target CI with similar dose distribution to the target.VMAT required fewer MU,shorten the treatment time significantly.The implementation of Synergy is stable and reliable.
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Objective To investigate the setup errors of super chest segment of esophageal cancer patients before radiotherapy delivery by KV cone beam CT,and evaluate the margin from CTV to PTV.Methods From 2010 to 2012,13 patients with super chest segment of esophageal cancer whose IMRT planning CT images were included in this study.Delineate target on the CT images of treatment planning and enlarge the margin of CTV to form ITV,then enlarge the margin of ITV gradually 10 times by 1 mm each time to form varied PTV,and create the plan according to the size of the PTV,simulate setup errors in the new plan to obtain the simulation of the actual exposure curve and find a suitable PTV to assure 95％ ITV volume as ever to approach the prescription dose,obtained the outside enlarge distance of CTV → PTV.Results The maximum setup errors in the direction of the anterior and posterior positioning was (3.42 ±2.19) mm.The margin of ITV→PTV is 5 mm which was figured out by PTN enlarging method.Compared to the original plan that under the condition of draw up the radiotherapy plan that based on the method of PTV enlarging obtained the CTV→PTV and simulate the actual dose distribution according to the setup errors:total lung V5,spinal cord D1cm3,increased by about 0.87％,4.95 Gy,heart V40,PTV D95,PTV V100,ITV D95,ITV V100 were reduced about 0.62％,4.95 Gy,8.38％,1.84 Gy,1.87％,all of them have statistically difference.Conclusions Range of external expansion of the left to right,superior to inferior and anterior to posterior is 7 mm,8 mm and 7 mm respectively,according to the method of PTV enlarging obtained the margin of CTV→PTV of super chest segment of esophageal cancer patients.
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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.