Radiotherapy plays an important role in the treatment of all stages of pancreatic cancer, and some therapeutic effects have been obtained. At present, it needs to be considered and practiced in many aspects that how to play the role of radiotherapy in the treatment of pancreatic cancer. It is related to the choice of dose mode, the accuracy of irradiation, the cooperation of other treatment methods and other factors. The emergence of precision radiotherapy technology and the subsequent change in the idea of radiotherapy will further improve the role of radiotherapy in the treatment of pancreatic cancer. Based on the relevant literatures at home and abroad and our own experience, this paper reviews the role of precision radiotherapy for pancreatic cancer.

Objective To preliminarily evaluate the efficacy and safety of intensity-modulated radiotherapy (IMRT) in the treatment of inoperable stage ⅣA thymoma.Methods A retrospective analysis of 15 patients with inoperable stage ⅣA thymoma receiving IMRT from January 2010 to December 2017 was performed.Among them,9 patients were male and 6 female,aged 31-83 years with a medianof 59 years.The dose of radiotherapy was 50 Gy/60 Gy/70 Gy/ 15-20 fractions for PTV/CTV/GTV.The short-term efficacy,overall survival rate and adverse reactions were analyzed.Results The follow-up rate was 100％.The median follow-up time was 48 months.The short-term partial remission rate was 93％(14/15).The 1-,3-and 5-year overall survival rates were 100％,75％ and 75％,respectively.One patient presented with grade 3 hematological reaction.Four patients died of tumors.Conclusion Preliminary findings demonstrate that IMRT is an efficacious and safe treatment of stage ⅣA thymoma,which can be applied for patients with unresectable thymoma.

Objective To investigate the acute adverse reactions of craniospinal irradiation with helical tomotherapy in medulloblastoma patients and its risk factors. Methods A total of 20 patients with medulloblastoma who received craniospinal irradiation with helical tomotherapy between October 2012 and September 2016 in Air Force General Hospital were selected. The acute adverse events of 20 patients during the treatment were record. According to National Cancer Institute Common Terminology Criteria Adverse Events (NCI-CTCAE) version 4.0, the adverse reactions were divided into the mild group (grade 0-Ⅱ) and severe group (grade Ⅲ-Ⅳ) adverse reactions. And the risk factors were also analyzed. Results The non-hematological adverse reactions included fatigue (55％), vomiting (45％) and headache (25％). The hematological adverse reactions included leukopenia (95％), thrombocytopenia (55％) and lower hemoglobin (45％), and the incidence of severe adverse reactions was 35％ (7/20), 20％ (4/20) and 0 ( 0/20 ) , respectively . Leukopenia occurred in 18 patients ( 90％) at the beginning of radiotherapy within 2 weeks, and thrombocytopenia occurred in 8 patients (40％) at the beginning of radiotherapy after 2 weeks. Single factor analysis showed that there were no statistical differences in hematological adverse events of gender, age and radiation dose of spinal cord (all P>0.05). The incidence of leukopenia for the patients who received the chemotherapy before the radiotherapy was higher than that for the patients without the chemotherapy before the radiotherapy (P< 0.05). Conclusions The hematological adverse reactions were the major acute adverse events during the craniospinal irradiation with helical tomotherapy in patients with medulloblastoma. Theincidence of leukopenia and thrombocytopenia is common, and the incidence of hematological adverse reactions is higher after the chemotherapy. Thus, the close monitoring of hemogram change and treatment of hematological adverse reactions in time during the radiotherapy should be taken into the consideration.

Objective To introduce the therapeutic procedures of helical tomotherapy based total marrow irradiation(HT-TMI), and validate the feasibility of TMI. Methods At 1 week before bone marrow transplantation,12 patients received TMI conditioning regimen at a prescriptive dose of 12 Gy in 3 times,once daily. Patient immobilization, CT simulation, target delineation, plan design and dosimetric verification were implemented in sequence according to the TMI procedures. The dosimetric paramaters of the target and normal tissues were analysed. The correlation between the dose verification and image-guided results was observed. Results Compared with total body irradiation(TBI), TMI could significantly reduce the irradiation dose to normal tissues. The median dose D50of all normal tissues except the oral cavity were lower than 6 Gy,where The D50of lens,brain,lung and liver are (1.8±0.1) Gy, (5.7±0.2) Gy, (5.2±0.2) Gy, and (4.6±0.2) Gy, respectively. Pass rate of γ Index was larger than 95% with 3mm/3% criterian for each section. The positioning error of head and neck was relatively lower than that of pelvis at x-axis,and was higher at z-axis.Conclusions Helical tomotherapy based TMI is a feasible and reasonable approach,which has evident dosimetric advantage.

Objective To observe the dynamic changes of serum CA19-9 level before and after the treatment of high-dose and low-fractionated Tomotherapy combined with chemotherapy for pancreatic cancer,and explore the corresponding prognostic,predictive and therapeutic effects.Methods The clinical characteristics and the survival of 75 patients with pancreatic cancer treated in the Department of Radiotherapy of Air Force General Hospital were analyzed retrospectively from December 2012 to June 2017.The effects of baseline CA19-9 and CA19-9 level at 4-6 weeks after the radiotherapy on patient prognosis were analyzed by Kaplan-Meier method and Log-rank test retrospectively.Results The median survival time (MST) was 13.8 months (2.0-58.0 months).The baseline serum CA19-9 was 1109 U/ml(4.70-70000 U/ml).The MST in the ＜ 1109 U/ml group and ≥ 1109 U/ml group were 14.0 months (95％ CI:10.04-22.96 months) and 9.0 months(95％ CI:7.75-13.25 months) respectively (x2 =6.31,P ＜0.05).The corresponding median progression-free survival (mPFS) was 7.0 months(95％ CI:5.58-8.42 months) and 5.0 months(95 ％ CI:3.81-6.20 months) respectively (x2 =8.51,P ＜ 0.05).The median CA19-9 level at 4-6 weeks after radiotherapy was 397.7 U/ml (11.02-43 250 U/ml).A total of 38 cases (38/49,77.6％) declined,and 11 cases (11/49,22.4％) increased.The MST of the declined and increased groups were 14.0 months(95％ CI:7.24-20.77 months) and 8.0 months(95％ CI:2.69-13.31 months) respectively (x2 =11.19,P ＜0.05).The corresponding mPFS were 5.5 months(95 ％ CI:4.05-6.95 months) and 4.0 months (95 ％ CI:1.98-6.02 months) respectively (x2 =9.12,P ＜ 0.05).The ROC curve determined that the cut-off for the decline of serum CA19-9 was 60.9％ at 4 to 6 weeks after radiotherapy.The MST of ≥ 60.9％ group and ＜ 60.9％ group were 33.5 months (95％ CI:0.24-66.76 months)and 9.0 months(95％ CI:6.92-11.08 months)respectively (x2 =13.80,P＜0.05).The corresponding mPFSwere 11.0 months(95％ CI:3.44-18.56 months)and 5.0 months(95％ CI:3.91-6.09 months)respectively (x2 =8.71,P＜0.05).Conclusions Patients with the baseline serum CA19-9 ＜ 1109 U/ml had a better outcome after hypofraction tomotherapy combined with chemotherapy.The decline of serum CA19-9 at 4-6 weeks after radiotherapy can serve as a prompt and effective predictor of the outcome and the progression of patients.The decline of serum CA19-9 ≥60.9％ in patients with pancreatic cancer is associated with a low possibility of disease progression in half a year,whose overall survival is better.

Objective To retrospectively analyze the clinical outcome of radiotherapy for unresectable renal cell carcinoma and renal pelvis and ureter cancer. Methods A total of 29 patients with unresectable renal cell carcinoma or renal pelvis and ureter cancer received radiotherapy from 2006 to 2015. Those patients were 18 males and 11 females aged between 41 and 95 years(median age 76 years). In those patients,17 had renal cell carcinoma and 12 renal pelvis and ureter cancer;14 had hematuria and 7 low back pain. All patients received dose-escalation radiotherapy,with 17 treated by gamma knife treatment and 12 by helical tomotherapy(HT). For the gamma knife treatment, the 50% isodose line was set as the prescribed dose line;the radiation dose was 3 to 5 Gy per fraction, with a total dose of 40-50 Gy around the planning target volume and 60-70 Gy around the gross tumor volume. HT was performed with a dose of 50/60/70 Gy in 15-20 fractions. Results For the primary lesion, the complete response(CR)and partial response (PR)rates were 17%(5/29)and 69%(20/29),respectively,yielding an overall response rate(CR+PR) of 86%. After treatment,93% of patients recovered from hematuria and 100% of patients recovered from low back pain. The 3-and 5-year sample sizes were 15 and 11, respectively. The 3-, and 5-year survival rates were 81%,and 81%,respectively,for renal cell carcinoma,and,69%,and 69%,respectively,for renal pelvis and ureter cancer. During treatment, 25 patients had grade 1-2 digestive system reaction and 20 patients had grade 1-2 bone marrow suppression. The radiation-induced toxicity was reduced by medication. Conclusions Radiotherapy is safe and effective for treating renal cell carcinoma and renal pelvis and ureter cancer. It can improve the local control and overall survival rates. Radiotherapy provides an effective way to treat unresectable renal cell carcinoma and renal pelvis and ureter carcinoma.

Objective To evaluate the effect of high-dose hypofractionated radiotherapy upon the quality of life (QOL) of patients diagnosed with pancreatic cancer. Methods In this prospective study, 50 patients with pancreatic cancer admitted to our hospital between 2016 and 2017 were recruited. All patients underwent high-dose hypofractionated helical tomotherapy. The prescription doses for PTV, CTV, and GTV were 50, 60, and 70 Gy in 15-20 fractions, 5 times per week. The QOL was evaluated by the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (QLQ-C30) and pancreatic cancer-specific (European Organization for Research and Treatment of Cancer QLQ-PAN26) questionnaires before, after, 1-month and 3-month after the radiotherapy to statistically compare the QOL changes before and after radiotherapy and subsequent follow-up. Results A total of 50 patients with pancreatic cancer were included. At the end of radiotherapy, the overall QLQ-C30 score did not differ from that before radiotherapy (P＝0. 330). At 1 month after radiotherapy, the overall QLQ-C30 score was significantly higher than that before radiotherapy (P＝0. 000). The overall QLQ-C30 scores did not significantly differ at 1-and 3-month after radiotherapy ( P＝0. 665). At 3 months after radiotherapy, social function score was considerably decreased (P＝0. 047), and the remaining function scores were equal to those at 1 month post-radiotherapy. The symptoms of fatigue in the QLQ-C30 questionnaire were slightly improved at the end of radiotherapy, which were mitigated at 1-month after radiotherapy and became stable at 3-month following radiotherapy. Pain, insomnia, loss of appetite and diarrhea did not significantly change at the end of radiotherapy, whereas were improved at 1 month after radiotherapy. Nausea and vomiting were aggravated at the end of radiotherapy ( both P＝0. 000), restored to the level before radiotherapy at 1 month after radiotherapy, and the symptoms were similar at 1-and 3-month after radiotherapy. Financial difficulty was worsened at the end of radiotherapy (P＝0. 046), acceptable at 1 month after radiotherapy and worsened at 3 months following radiotherapy. In the QLQ-PAN26 questionnaire, the symptoms of pancreatic pain (backache, nocturnal pain) were mitigated at the end of radiotherapy (P＝0. 009, P＝0. 000), and further alleviated at 1 month after radiotherapy. No significant difference was noted at 1-and 3-month after radiotherapy. The body weight loss was slightly mitigated compared with that before radiotherapy ( P＝ 0. 000 ), and further improved at 1 month after radiotherapy ( P＝0. 024). No significant difference was noted at 1-and 3-month after radiotherapy ( P＝0. 226). Conclusion High-dose hypofractionated radiotherapy can significantly enhance quality of life of pancreatic cancer patients at 1- and 3- month following radiotherapy.This study further demonstrated the clinical value of high-dose hypofractionated radiotherapy in improving the quality of life on the basis of previous studies showing that high-dose hypofractionated radiotherapy can significantly improve the local control rate and survival rate of pancreatic cancer.

Objective To explore the curative effect and adverse reaction of applying stereotactic radiotherapy to primary lesion inside chest cavity of patients with oligometastasis non-small cell lung cancer and rendering radical radiotherapy to all metastases. Methods 43 patients with≤5 metastases of non-small cell lung cancer received initial treatment during 2009-2015 in our department were analyzed;the stereotactic radiotherapy was adopted to implement radical radiotherapy on primary lesion and all metastases. The average and neutral position BED10 respectively were 101416 Gy and 102700 Gy,the number of neutral position chemotherapy period was 4. Kaplan-Meier method, survival analysis, Cox model, multi factor Prognosis analysis were used. Results By the end of January 10,2017 in 36 months' neutral position follow-up visit, the total effective rate of lesion treatment of 86%;the survival rates after 1,2 and 3 years respectively were 74%, 70% and 51%. Neutral survival time was 48 months, and the progression-free time of neutral position was 15 months. Multi-factor analysis indicated that,ECOG<2 and ECOG≥2(P=0000),BED10<100 Gy and BED10≥100 Gy ( P=0006) generated obvious influence on survival prognosis. About 90% of the patients only got 1-2 degree of adverse reaction without emerging treatment related death. Conclusions On the premise of systematic therapy of oligometastasis non-small cell lung cancer, combined with radical radiotherapy of primary lesion and metastasis can obviously improve patients ' overall survival and progression-free survival,the adverse reaction is durable.

Objective To compare the tumor sizes of primary lesions in pancreatic cancer based on CT scan and postoperative pathological analysis and measure the extent of filtration under a microscope,and to determine the CTV in radiotherapy target delineation.Methods A total of 19 patients with pancreatic cancer who were admitted to PLA General Hospital and Air Force General Hospital,PLA from 2013 to 2014 were analyzed.In 15 patients,the maximum diameters of tumor cross-section were measured based on the images of preoperative multi-slice spiral CT and postoperative gross samples,respectively.In 19 patients,the extent of tumor infiltration was measured on pathological sections under a microscope and the actual extent of infiltration was calculated.The paired t-test was applied to analyze the differences in the results of different measurement methods.Results In the 15 patients,the maximum tumor diameters measured with gross samples and CT scan were 33.6 mm and 30.1 mm,respectively (P=0.000),and the median and mean of the differences were 3.1 mm (1.2-8.0 mm) and 3.6±2.0 mm,respectively (95％ CI 1.2-6.0).In the 19 patients,the maximum actual infiltration distance and the maximum distance measured were 3.50 mm and 3.19 mm,respectively (P=0.000),and the median and mean of the differences were 0.31 mm (0.15-0.50 mm) and 0.30±0.09 mm,respectively.The maximum distance between the margin of primary lesions and the infiltrating lesions was 5.21 mm,with a median of 3.34 mm (2.19-5.21 mm) and a mean of 3.50± 0.88 mm (95％ CI 2.19-5.06).Conclusions Contrast-enhanced CT scan underestimates the actual size of primary lesions in pancreatic cancer,and an extension of 5 mm outside gross tumor volume (GTV) as CTV may not be sufficient.It is recommended to extend another 1-3 mm outside GTV as CTV.

Objective:To investigate the prognostic value of18F-FDG PET/CT by calculating maximal standard uptake values(SUVmax) in patients with pancreatic carcinoma of TOMO knife radiotherapy.Methods:Sixty five cases of pancreatic carcinoma who underwent18F-FDG PET/CT scan before TOMO radiotherapy were reviewed retrospectively, the18F-FDG uptake of primary tumors was measured with the SUVmax. SUVmax<3.0 was divided into group A(32 cases), SUVmax≥3.0 was divided into group B(33 cases), the relationship of SUVmax and other clinical factors with the survival of the 65 patients were analyzed.Results:By Log-rank univariate analysis showed that the differences in group A(SUVmax<3.0) and group B(SUVmax≥3.0) in patiengts with middle survival time was statistically significant(15.5:7 months)atP=0.001. TNM stages(x2=6.625,P<0.010), CA19-9(x2=10.298,P<0.001) and GTV dose(x2=8.054, P<0.005) were also statistically different at (P<0.05). Multivariate analysis showed that the SUVmax and preoperative serum CA19-9 level were independent risk factors that prevent the long-term survival of the prognosis of patients in this group.Conclusion: SUVmax has a certain clinical value in predicting the prognosis of patients with pancreatic cancer, and can guide clinical diagnosis and treatment planning, and extend the lifespan of patients with pancreatic carcinoma.