Objective:To analyze the invasion characteristics and prognostic factors of patients with Masaoka-Koga stage Ⅲ thymoma.Methods:The tumor invasion characteristics of 179 patients who were diagnosed with Masaoka-Koga stage Ⅲ thymoma and treated in Affiliated Cancer Hospital of Zhengzhou University from January 2000 to June 2018 were analyzed retrospectively. According to the treatment methods, all patients were divided into the radical operation group ( n=94), palliative operation group ( n=39) and simple biopsy group ( n=46). The χ2 test was used to compare the classified variables, Kaplan- Meier method was utilized to calculate the cumulative survival rate, log-rank method was used for group comparison and univariate analysis, and Cox’s regression model was used for multivariate analysis. Results:Mediastinal pleural invasion (86.0%) was the most common site, followed by pericardium (50.8%), great vessel (40.8%) and lung (36.3%). The proportion of macrovascular invasion in the radical operation group was 14.9%, significantly lower than 79.5% and 60.9% in the palliative surgery group and biopsy group (both P<0.001). Multivariate analysis showed that the nature of operation ( P<0.001), age ( P=0.011), radiotherapy ( P=0.020) were the independent factors affecting overall survival (OS), while nature of operation ( P<0.001), age ( P=0.004), radiotherapy ( P=0.020), number of invasive organs ( P=0.023) and pathological type ( P=0.016) were the independent factors affecting progress-free survival (PFS). Conclusions:For patients with Masaoka-Koga stage Ⅲ thymoma, mediastinal pleura is the most common site of invasion, pericardium, lung and great vessels are also commonly invaded. The invasion of mediastinal pleura, pericardium and lung exerts slight effect on surgical resectability, whereas great vessel involvement can significantly affect surgical resectability. OS and PFS in patients undergoing radical resection are significantly better than those in patients treated with palliative resection and biopsy. Radical resection is the most important factor affecting prognosis.

Objective To compare the dose distributions of the volumetric modulated arc therapy ( VMAT) for early stage non?small cell lung cancer ( NSCLC) using conventional flattening filter ( FF) and the flattening filter free ( FFF) beams and to verify the dose calculation accuracy of the FFF beam through a three?dimensional verification system. Methods The treatment plans of 20 patients ( 2015 years hospitalized) treated with SBRT for early stage NSCLC using a TrueBeam accelerator were retrospectively analyzed. The patients were scanned with 4DCT and the average density projection images were used for organ segmentation and treatment planning using an Eclipse plan system. Two volumetric modulated arc therapy ( VMAT) plans with FF and FFF were designed with the same planning parameters for each patient. The dose distributions between the two plans were compared and their dose verifications were assessed with the ArcCheck device. Results With the same dose coverage for the target, there was no significant difference in the dose compatibility index 100%(CI100%) between FF and FFF beams (P=0. 82).CI80% and CI50% of FFF plan were lower than that of FF plan (P=0. 02,0. 01).The dose significantly decreased in the FFF plan comparing with the FF plan for the ipsilateral lung and the total lung (P<0. 01 for both).There was no significant difference between monitor units of the FF and FFF plans ( P=0. 34) ,while the delivery time of FFF was significant shorter than that of FF (P<0. 01).The DVH passing,γ pass rates and the absolute dose deviations of the FF and FFF plans at the central point were not significantly different ( P=0. 05,0. 16, 0. 26) . Conclusions FFF beams for NSCLC patients with VMAT planning can significantly improve the dose distribution compatibility and reduce radiation doses to lung. The beam delivery with FFF beams was also faster. Furthermore,the three?dimensional dose verification confirmed that the dose calculation in Eclipse plan system using FFF beams for VMAT plans were accurate and met the clinical need.

Objective: To compare the effect of neoadjuvant chemoradiotherapy (NCRT) and neoadjuvant chemotherapy (NCT) on the survival of patients with esophageal cancer. Methods: Clinical data of 275 cases of thoracic esophageal squamous cell carcinoma treated with neoadjuvant therapy combined with surgery from December 2011 to December 2015 were analyzed retrospectively. The data of treatment and follow-up were complete and analyzable. There were 70 cases in the NCRT group and 205 cases in the NCT group. The survival rate was calculated by Kaplan-Meier method and statistically compared by log-rank test, and multivariate analysis was performed by Cox regression model. Results: The median follow-up time was 32(3-84) months. The median survival time and recurrence-free survival time was 42(3-84) months and 30(3-84) months, respectively. The overall 3-and 5-year survival rates were 56.8% and 45.9%, respectively, and the 3-and 5-year recurrence-free survival rates were 45.1% and 38.9%, respectively. The median survival time in the NCRT and NCT groups was 46(7-84) and 40(4-74) months, and the median recurrence-free survival time was 31(3-84) and 28(3-69) months, respectively. The 3-and 5-year overall survival of the two groups were 59.1%, 47.1% and 56.3%, 47.5%(P=0.515), and the 3-and 5-year recurrence-free survival were 44.5%, 40.1% and 47%, 39%, respectively. There was no significant difference in the survival between two neoadjuvant therapy modes (P=0.554). Multivariate analysis showed that postoperative pathological TNM staging was an independent factor affecting the prognosis of patients with esophageal cancer (P=0.001). Conclusions The survival results of NCRT are similar to those of NCT. Postoperative pathological staging is an independent survival factor.

Objective: To investigate the feasibility of assessing the treatment response using diagnostic-quality CT imaging features during radiotherapy for esophageal cancer. Methods: Thirty-three patients with stage Ⅰ to IV esophageal cancer undergoing intensity-modulated radiotherapy were recruited in this study. CT images were acquired using a CT-on-rail imaging system. Imaging data of CT images including gross tumor volume (GTV), the volume of spinal cord and non-irradiated tissue (NIT), CT mean (MCTN), standard deviation , and skewness were collected and analyzed by using MIM image processing system. Patients were divided into the effective group (complete remission and partial remission, n=24) and ineffective group (no change and progression, n=9) based on the outcomes of 3-month follow-up. The imaging data were statistically compared between two groups using the self-designed Matlab software. Results: The tumor volume and MCTN of 33 patients were gradually decreased with the increase of radiotherapy dose. The tumor volume and MCTN were decreased by 42.46% and 5.76 HU in the effective group, more significant compared with 21.76% and 3.66 HU in the ineffective group (both P<0.005). The skewness in the ineffective group was decreased by 0.503 with the increasing radiation dose, whereas that in the effective group was increased by -0.450(P=0.034). Spinal cord and NIT did not significantly change with the increasing radiation dose. Conclusion Analysis of the characteristic data of CT images of patients with esophageal cancer during radiotherapy may early predict the clinical efficacy of radiotherapy.

Objective To evaluate the recurrence pattern and identify the risk factors of esophageal squamous cell carcinoma after neoadjuvant therapy combined with surgery.Methods Clinical data of 275 patients with thoracic esophageal squamous cell carcinoma treated with neoadjuvant therapy combined with surgery from December 2011 to December 2015 were retrospectively analyzed.The follow-up data of the enrolled patients were complete and analyzable.The recurrence pattern,recurrence time,recurrence location and influencing factors after neoadjuvant therapy in combination with surgery were analyzed.The recurrence rate was calculated by Kaplan-Meier method.The multivariate analysis was performed by Cox regression model.Results The median follow-up time was 32 (3-84) months,and the median time of the first recurrence was 10.6(2.0-69.1) months.The 1-,2-and 3-year recurrence rates were 32.0％,45.1％ and 52.3％,respectively.A total of 152 cases (55.3％) had recurrence.Among them,77 cases (50.6％) had local-regional recurrence (LRR),34 cases (23.4％) had distant metastasis (DM),33 cases (21.7％) had LRR+DM and 8 cases (6.0％) had recurrence in unknown site.Among the patients with LRR,lymph node recurrence was the most common (n =98,89.1％).For DM patients,lung metastasis (n =33,49.3％),liver metastasis (n=16,23.9％),bone metastasis (n=14,20.9％) and non-regional lymph node metastasis (n=14,20.9％) were commonly observed.The multivariate analysis showed that postoperative T stage (P=0.008),N stage (P＜0.001) and the number of lymph node dissection (P＜0.001) were the independent risk factors for recurrence after treatment.Conclusions The recurrence rate after neoadjuvant therapy remains relatively high for esophageal squamous cell carcinoma,and the regional lymph node is the most common site of recurrence.Postoperative pathological T staging,N staging and the number of lymph node dissection are the independent risk factors for recurrence after treatment.

Objective:To evaluate the role of salvage radiotherapy in the re-treatment of patients with regional lymph node oligo-recurrence after radical surgery for esophageal squamous cell carcinoma.Methods:Clinical data of patients diagnosed with thoracic esophageal squamous cell carcinoma treated with radical surgery and developed regional lymph node oligo-recurrence ( n=1-3) from January 2013 to January 2016 were retrospectively analyzed. A total of 74 cases with intact clinical data were extracted for analysis. The survival analysis was performed by Kaplan-Meier method. Group comparison was conducted by Log-rank method. Results:The median overall survival (OS) after recurrence was 9(2.5-43) months, and the median progression-free survival time (PFS) was 4(1-33) months. There were 47 cases in the salvage radiotherapy group and 27 cases in the non-radiotherapy group, and the objective response rates were 77%(36/47) and 30%(8/27), respectively. Patients in the salvage radiotherapy group had better OS ( P=0.042) and PFS ( P=0.01) compared with their counterparts in the non-radiotherapy group. Among the patients who received salvage radiotherapy, involved field irradiation and elective nodal irradiation yielded similar OS ( P=0.963) and PFS ( P=0.599), and patients treated an irradiation dose ≥ 60Gy had better OS ( P=0.001) and PFS ( P=0.001) compared with those with dose< 60Gy. Conclusions:Local salvage radiotherapy is an effective treatment of esophageal squamous cell carcinoma with regional lymph node oligo-recurrence after radical surgery. Salvage radiotherapy has better OS and PFS compared with non-radiotherapy. Prospective clinical studies should be carried out to standardize the target and dose of radiotherapy, and to further clarify the effect of radiotherapy.

Objective: To evaluate the clinical efficacy and prognostic factors of recurrent esophageal squamous cell carcinoma after neoadjuvant therapy combined with surgery. Methods: From December 2011 to December 2015, 152 cases of recurrent thoracic esophageal squamous cell carcinoma after neoadjuvant therapy combined with surgery were retrospectively analyzed. The overall survival (OS) after treatment failure, clinical efficacy and prognostic factors of different salvage treatments were analyzed. OS was calculated by Kaplan-Meier method. Prognostic analysis was performed by using multivariate Cox regression model. Results: The median interval of the first recurrence was 10.6(2.0 to 69.1) months. The median OS after recurrence was 8.0(0.8 to 43.3) months. The 1-, 2-and 3-year OS rates after recurrence were 36.0%, 15.1% and 5.2%, respectively. The median OS of patients with locoregional recurrence alone, distant metastasis alone and locoregional recurrence combined with distant metastasis was 11.3(1.8 to 43.3) months, 6.7(1.2 to 28.6) months and 5.1(0.8 to 22.9) months, respectively. Multivariate analysis demonstrated that neoadjuvant chemotherapy (P=0.009), ypTNM stage (P=0.012), comprehensive treatment after recurrence (P=0.000) and locoregional recurrence (P=0.026) were independently correlated with the OS of patients with recurrent esophageal squamous cell carcinoma. Conclusions Neoadjuvant therapy, ypTNM stage, recurrence pattern and post-recurrence treatment are the independent risk factors for clinical prognosis of patients with recurrent esophageal squamous cell carcinoma after neoadjuvant therapy combined with surgery. Clinical prognosis of patients with recurrent esophageal squamous cell carcinoma after neoadjuvant therapy is not satisfactory. After recurrence, combined treatment mode should be adopted according to the site of recurrence and neoadjuvant treatment mode to maximize the benefits of salvage treatment.