| Part ?:Helical tomotherapy for advanced esophageal cancer improves target conformity and homogeneity:A comparison with fixed-field intensity-modulated radiotherapyPurpose:To evaluate the usefulness of helical tomotherapy(HT)in the treatment of advanced esophageal cancer(EC)and compare target homogeneity,conformity and normal tissue doses between HT and fixed-field intensity-modulated radiotherapy(ff-IMRT).Methods and Materials:In all,23 patients with cT3-4N0-1M0-la thoracic EC(upper esophagus,9 patients;middle esophagus,6;distal esophagus,6 and esophagogastric junction,2)who were treated with ff-IMRT(60 Gy in 30 fractions)were re-planned for HT and ff-IMRT with the same clinical requirements.Comparisons were performed using the Wilcoxon matched-pair signed-rank test.Results:Compared with ff-IMRT,HT significantly reduced the homogeneity index for thoracic,upper,middle and distal ECs by 38%,31%,36%and 33%,respectively(P<0.05).The conformity index was increased by HT for thoracic,upper and middle ECs by 9%,9%and 18%,respectively(P<0.05).Target coverage was improved by 1%with HT(P<0.05).The mean lung dose was significantly reduced by HT for thoracic and upper ECs(P<0.05).The V20(volume receiving at least 20 Gy)and higher dose volumes of the lungs were decreased by HT in all cases,but the differences were significant for thoracic,upper and distal ECs(P<0.05),with reductions of 2.1%,3.1%and 2.2%,respectively.HT resulted in a larger lung V5 for thoracic,upper,middle and distal ECs,with increases of 3.5%,1.5%,7.2%and 3.2%,respectively.Heart sparing was significantly better with HT than with ff-IMRT in terms of the V30 and V40 for thoracic,upper,middle and distal ECs(P<0.05).Conclusion:Compared to ff-IMRT,HT provides superior target coverage,conformity and homogeneity,with reduced the volume of high doses to the lungs and heart for advanced EC.HT may be a treatment option for advanced EC,especially upper EC.Part ?:Dosimetric and clinical outcomes after volumetric modulated arc therapy for carcinoma of the thoracic esophagusPurpuse:The efficiency of radiation delivery via volumetric modulated arc therapy(VMAT)is indisputable,but outcomes after VMAT for thoracic esophageal carcinoma are largely unknown.Methods and Materials:We retrospectively analyzed 65 patients with thoracic esophageal cancer who received VMAT to 50.4 Gy(range 45-50.4 Gy)with concurrent chemotherapy from November 2012 to March 2016 at a single tertiary cancer center.We then used propensity score matching to match these 65 patients with another 130 patients treated with step&shoot IMRT(ssIMRT)and concurrent chemotherapy.Differences in continuous variables and categorical variables were examined with independent-sample t or Wilcoxon tests and Chi-square tests.Results:Dosimetrically,VMAT had a higher conformity index(87.75±10.70 VMAT vs.83.20±9.42 ssIMRT,P=0.003),a higher heart V5 and a lower V50 than ssIMRT,but lung V5-20,heart V30,heart V40,cordmax,and homogeneity index were similar.At median follow-up intervals of 14.3 months(range 3.8-34.5 months)for VMAT and 31.8 months,(range 1.8-117.2 months)for ssIMRT,overall survival(OS)rates were similar between treatments(93.5%VMAT vs.91.5%ssIMRT at 1 year;60.0%VMAT and 61.4%ssIMRT at 2 years,P=0.868).Recurrence-free survival rates were similar(73.3%VMAT vs.79.5%ssIMRT at 1 year,59.9%VMAT and 61.8%ssIMRT at 2 years,P=0.614),as were pathologic complete response rates(31.2%VMAT vs.23.3%ssIMRT,P=0.41)and toxicity(radiation pneumonitis 9%VMAT vs.15.4%ssIMRT;pericardial effusion 2%VMAT vs.7%ssIMRT;esophageal fistula and stricture,9%VMAT vs.13%ssIMRT;and postoperative complications;P for all>0.05).Conclusions:Compared with ssIMRT,VMAT had better target conformity with similar organ sparing and comparable rates of survival,recurrence,and toxicity.These results suggest that VMAT can be safe and effective for esophageal cancer.Part III:Definitive Chemoradiotherapy for Esophageal Cancer in the Elderly:Clinical Outcomes for Patients Exceeding 80 years oldPurpose:The optimal treatment approach for patients?80 years("elderly")with esophageal cancer is not well established.We assessed the clinical outcomes of elderly patients treated with definitive chemoradiotherapy(CCRT)at our institution.Methods and Meterials:56 patients?80 years with esophageal cancer treated with CCRT between 2001 and 2016 were propensity score matched 1:2 to generate two younger patient cohorts treated with CCRT without surgery("Intermediate",65-79 years;n=112,and "Younger"<65 years;n=112).Treatment related toxicity was assessed using the Common Terminology Criteria for Adverse Events(CTCAE)version 4.0.The rates of overall survival(OS)and recurrence free survival(RFS)were calculated with Kaplan-Meier method.Results:The median age of the 3 cohorts were 81 years(elderly,80-92 years),71 years(intermediate,65-79 years),and 58 years(younger,20-64 years).The elderly cohort was more likely to have cardiac comorbidities.While the cCR rate deviated significantly among the three cohorts,(78%,72%and 56%with P=0.004),the data failed to identify statistically significant differences among RFS,2-and 5-year OS,nor in median survival,which was 28.5months,37.8months,and 23.6months(P=0.468),respectively.The overall severe toxicity rate were 38%,32%,and 30%,respectively(P=0.644),including comparable rate of radiation pneumonitis(P>0.05).The elderly cohort,however,did exhibit statistically significant evidence of an increased rate of severe radiation pneumonitis(?grade 3)which was observed to be 11%vs.4%and 0%,respectively(P=0.003).Conclusions:The studied elderly population exhibited evidence of similar long-term clinical efficacy following definitive CCRT when compared to cohorts of younger patients with similar prognostic status.An increased rate of pulmonary toxicity was identified,without evidence of difference for non-pulmonary severe adverse events.Understanding prognostic risk factors of pulmonary toxicity following CCRT may effectuate improved long-term outcomes for elderly population.Part ?:Patterns and Predictors of Recurrence after Radical Resection of ThymomaPurpose:Recurrence of thymomas even after complete resection is common,but the relapse patterns remain controversial.This study aimed to define the patterns and predictors of relapse after complete resection of thymoma.Methods and Meterials:A single-institution retrospective study was performed with 331 patients who underwent radical resection of thymoma between 1991 and 2012.Results:After a median follow-up of 59 months,the recurrence rate was 6.9%(23/331).Relapse occurred in 23 patients with the pleura(14)and tumor bed(6)as the most common sites of recurrence.According to the definitions of the International Thymic Malignancy Interest Group,10(43.5%)patients had local relapse,15(65.2%)had regional relapse,10(43.5%)had distant relapse.The difference in survival following relapse between lung and regional relapse was statistically significant(P=0.027)but that between lung and distant relapse was not(P=0.808).The recurrence rates correlated with the initial Masaoka stage.Further,recurrence also correlated with World Health Organization(WHO)tumor type.The recurrence-free survival rates in patients with tumor size>8 cm were worse than those of patients with tumor size<8 cm(P=0.007).Tumor size was also correlated with stage(r = 0.110).As tumor becomes larger,the stage is more advanced(P = 0.023).Multivariate analysis showed that Masaoka stage(P =0.005),tumor size(P = 0.033),and WHO histological type(P = 0.046)were predictive factors of relapse.Conclusion:Regional recurrence is the most common relapse pattern but local and distant relapse are also common.Advanced Masaoka stage,larger tumor size,and type B3 are risk factors of recurrence.Lung relapse should be considered distant relapse.Further,tumor size was correlated with Masaoka stage and therefore should be considered in the staging system.Part ?:Results and Prognostic Features of Recurrent ThymomaPurpose:This study sought to analyze the results and prognosis of recurrent thymoma.Methods and Meterials:Between 1991 and 2012,32 patients that developed recurring thymoma after radical resection were reviewed.Results:The median follow-up duration after initial treatment and recurrence was 89 and 49.5 months,respectively.The median recurrence free internal(RFI)was 42 months,and the 5-year overall survival(OS)rates after recurrence was 65.5%.Among 32 patients that relapsed,7 underwent re-resection,18 experienced nonsurgical management,5 failed to receive treatment after recurrence,and 2 remain unknown.The 5-year OS rates after recurrence of the surgery group and the nonsurgery group were 100%and 73.1%,respectively(P=0.210).In the nonsurgery group,9 received radiotherapy,including 4 with local recurrence and 5 with regional or distant recurrence.The 5-year OS rates after recurrence of the local recurrence group and the regional or distant recurrence group were 100%and 60%,respectively(p=0.34).In univariate analysis,age(<55 years,P =0.009),local and regional recurrence(P = 0.022),and late recurrence(RFI>20 months,P=0.038)indicated good prognostic factors.of recurrent thymoma.However,Masaoka stage at initial detection,WHO types at initial detection,tumor size,PORT,and single recurrence had no statistically significant impact on survival of recurrent thymoma(P>0.05).Conclusion:Recurrent thymoma should be actively treated.Reoperation for resectable diseases is associated with better outcome and relative safety,and it should be recommended.In patients with local recurrence,radiotherapy may receive comparable survival to re-operation,which might be recommended for inoperable patients.Radiotherapy/chemotherapy probably is the treatment of choice for inoperable patients with regional or distant recurrence.Age<55 years,local and regional recurrence,and longer RFI(RFI>20 months)are associated with a positive prognosis. |
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