Objective To explore the application effect of artifact removal technique of Discovery RT (GE Inc) in organ segmentation and radiotherapy planning. Methods Twelve patients with head and neck tumors carrying irremovable metal dentures,who received radiotherapy at the Fourth Affiliated Hospital of Nanjing Medical University from September 2021 to February 2024,were enrolled in the study. AccuContour was used to perform organs-at-risk (OAR) segmentations separately on CT image processed by metal artifact reducing algorithm and conventional CT image. Dice similarity coefficient (DSC),Hausdorff distance (HD) and the mean CT values of OAR with or without metal artifacts were compared. Both the processed CT images and original images were transferred to Monaco planning system. Dose calculation was conducted on the images with metal artifacts,and the calculated plans were mapped to the artifact-free images for analyzing the dosimetric differences of OAR. Results The HD of the throat,oral cavity and mandible were slightly higher. The mean CT values of the tissues in images before and after artifact removal were not statistically different except for the trachea (P<0.05),and the mean oral CT value at the artifact level differed significantly in two groups (P<0.05). The radiation dose of different tissues in the radiotherapy plan before and after artifact removal only showed statistical differences in the superior constrictor musde of pharynx. The percentages of irradiation dose differences for the tissues ranged from 0 to 6.45％,with the largest fluctuation in the left lens (-2.92％±3.95％) and the right lens (1.29％±3.35％). Conclusion Manual delineation is required for the tissues close to metal artifacts due to the remarkable effects on CT values and planned dose,but there is few differences in the other tissues.

Objective To explore the application effect of artifact removal technique of Discovery RT (GE Inc) in organ segmentation and radiotherapy planning. Methods Twelve patients with head and neck tumors carrying irremovable metal dentures,who received radiotherapy at the Fourth Affiliated Hospital of Nanjing Medical University from September 2021 to February 2024,were enrolled in the study. AccuContour was used to perform organs-at-risk (OAR) segmentations separately on CT image processed by metal artifact reducing algorithm and conventional CT image. Dice similarity coefficient (DSC),Hausdorff distance (HD) and the mean CT values of OAR with or without metal artifacts were compared. Both the processed CT images and original images were transferred to Monaco planning system. Dose calculation was conducted on the images with metal artifacts,and the calculated plans were mapped to the artifact-free images for analyzing the dosimetric differences of OAR. Results The HD of the throat,oral cavity and mandible were slightly higher. The mean CT values of the tissues in images before and after artifact removal were not statistically different except for the trachea (P<0.05),and the mean oral CT value at the artifact level differed significantly in two groups (P<0.05). The radiation dose of different tissues in the radiotherapy plan before and after artifact removal only showed statistical differences in the superior constrictor musde of pharynx. The percentages of irradiation dose differences for the tissues ranged from 0 to 6.45％,with the largest fluctuation in the left lens (-2.92％±3.95％) and the right lens (1.29％±3.35％). Conclusion Manual delineation is required for the tissues close to metal artifacts due to the remarkable effects on CT values and planned dose,but there is few differences in the other tissues.

Objective To understand preliminaryly the epidemiological trend of lung cancer in recent years by retrospective analysis of 2 403 cases of lung cancer in Zhongnan Hospital of Wuhan University from 2013 to 2017.Methods The clinical data of patients with primary bronchogenic cancer diagnosed in Zhongnan Hospital of Wuhan University from 2013 to 2017 were collected.The clinical data such as gender,age,history of tobacco and alcohol,operation,pathological type,clinical stage and epidermal growth factor receptor (EGFR) gene mutation were analyzed statistically.Results A total of 2 403 cases of lung cancer were collected,including 1 766 males and 637 females.There was no significant difference in gender ratio between male and female in five years (x2 =8.481,P =0.075).There were 2 398 cases with age information,the male-to-female ratios of lung cancer patients aged less than 40,40-49,50-59,60-69,70-79,80 and over were 0.9 ∶ 1.0,1.4 ∶ 1.0,2.4 ∶ 1.0,3.6 ∶ 1.0,3.4 ∶ 1.0 and 3.3 ∶ 1.0 respectively,and the difference was statistically significant (x2 =59.004,P ＜ 0.001).The composition difference of adenocarcinoma was not statistically significant in five years (x2 =2.165,P =0.705).There was no statistically significant difference in the composition ratio of squamous cell carcinoma (x2 =4.788,P =0.310).Adenocarcinoma accounted for 43.15％ (762/1 766) and 81.95％ (522/637) of the pathological types of male and female patients respectively,and the difference was statistically significant (P ＜ 0.001).Squamous cell carcinoma accounted for 39.01％ (689/1 766) and 7.28％ (47/637) respectively,and the difference was statistically significant (P ＜ 0.001).The proportion of squamous cell carcinoma in smoking patients was 42.99％ (583/1 356),which was significantly higher than that in non-smoking patients (14.61％,153/1 047);the proportion of squamous cell carcinoma in drinking patients was 40.56％ (277/683),which was higher than that in nondrinking patients (26.69％,459/1 720),and the differences were statistically significant (both P ＜ 0.001).A total of 1 252 patients underwent surgery,accounting for 52.10％ (1 252/2 403) of the total cases.The surgical rate of small cell carcinoma was 21.72％ (48/221),and that of non-small cell carcinoma was 55.18％ (1 204/2 182).In five years,the surgical rates of lung cancer patients were 55.11％ (221/401),51.53％ (252/489),58.23％ (244/419),53.18％ (276/519) and 45.04％ (259/575) respectively,and there was significant difference in the proportion of surgical and non-surgical patients in each year (x2 =19.553,P =0.001).A total of 483 patients were tested for E GFR mutation,the EGFR mutation rate was 58.8％ (251/ 427) in adenocarcinoma patients and 15.6％ (5/32) in squamous cell carcinoma patients.Among lung cancer patients aged less than 40,40-49,50-59,60-69,70-79,80 and over,the proportions of adenocarcinoma were 76.74％ (33/43),62.39％ (136/218),57.73％ (381/660),47.95％ (455/949),52.22％ (235/450) and 52.56％ (41/78) respectively,and the difference was statistically significant (x2 =33.078,P ＜ 0.001);the proportions of squamous cell carcinoma were 9.30％ (4/43),21.56％ (47/218),28.03 ％ (185/660),34.14％ (324/949),32.44％ (146/450) and 35.90％ (28/78) respectively,and the difference was statistically significant (x2 =26.977,P ＜ 0.001).The difference of composition ratio of TNM staging was statistically significant in five years (x2 =21.003,P =0.034).Conclusion There has been no significant change of male-to-female ratio in patients with lung cancer in the past five years.With the increase of age,the male-to-female ratio increases first and then decreases.The proportion of adenocarcinoma and squamous cell carcinoma has not increased or decreased significantly in the past five years.Adenocarcinoma and squamous cell carcinoma are both common in male lung cancer patients,while the pathological type of female patients is mainly adenocarcinoma.Squamous cell carcinoma is highly prevalent in smokers and drinkers.The surgical rate of squamous cell carcinoma is higher than that of adenocarcinoma,and the surgical rate of non-small cell lung cancer is higher than that of small cell lung cancer.The EGFR mutation rate is higher in adenocarcinoma.With the increase of age,the proportion of adenocarcinoma in all pathological types tends to decrease,while that of squamous cell carcinoma tends to increase.The patients' TNM staging has a downward trend,and the operation rate decreases slightly.

Background and objectiveEpidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), which targets EGFR, plays an important role in non-small cell lung cancer (NSCLC) treatment. Patients with somatic acti-vating mutations in theEGFR gene exhibit signiifcant initial response but eventually develop resistance to TKI. hTe second mutation (T790M) of theEGFR gene is the possible main cause of drug resistance. hTe aim of this study is to investigate the effect of ionizing radiation on EGFR-TKI resistance caused by T790M mutation in NSCLC cell lines.MethodsWe selected H1975 and H3255 as research subjects and tested the mutation states by real-time PCR analysis. Radiosensitivity was deter-mined by clone-forming test, and drug resistance was detected in different groups by MTT assay.Results H1975 is anEGFR double mutant (L858R plus T790M), whereas H3255 is anEGFR single mutant (L858R). hTe cell survival fractions of H1975 and H3255 did not vary in different treatment groups (P=0.952). hTus, T790M mutation did not affect the radiosensitivity of NSCLC cell lines. hTe IC50 of H1975 in the 2.5 Gy group [(0.678; 2±0.373) μmol/L] was statistically signiifcant compared with that in the 0 Gy normal control group [(3.520±0.821) μmol/L] (P=0.008). hTe drug tolerance of the H1975 cell line by 89.5 dropped to 39.2 times.ConclusionIonizing radiation can reduce TKI resistance caused by T790M mutation in NSCLC cell lines. Our results provide a research basis for futurein vivo and clinical studies. Radiotherapy combined with EGFR-TKI treatment can be a promising strategy to overcome T790M-mediated drug resistance.

Objective To evaluate the survival and adverse effects of adjuvant concurrent temozolomid (TMZ) combined with radiochemotherapy in postoperative patients with high grade intracranial glioma.Methods 84 postoperative patients with high grade intracranial glioma were randomly divided into the observation group (42 cases including 25 grade Ⅲ cases and 17 grade Ⅳ cases) and the control group (42 cases including 23 grade Ⅲ cases and 19 grade Ⅳ cases).All patients were treated with concurrent radiochemotherapy after surgical operations,the total radiation dose was 60-66 Gy.The patients in observation group were given daily oral TMZ 75 mg/m2 during radiotherapy.4 weeks after radiotherapy,all of the patients received 6 cycles of TMZ,each cycle lasted 5 days with 28 days interval between each cycles.150 mg/m2 of TMZ was given for the first cycle for 5 days,followed by 200 mg/m2 of drug for the rest of the cycles if no significant drug related toxicities were observed.Results The overall response rates (CR+ PR) were 71.7 ％ (33/46) in the observation group,and 32.6 ％ (15/46) in the control group,and with significant difference between the two groups (P ＜ 0.001).The 1,2 and 3 year survival rates of patients in the observation group were 71.7 ％,47.8 ％,36.9 ％,and 56.5 ％,26.1％,15.2 ％ in the control group.The significant differences were found in 2-year and 3-year survival rates between the two groups (P =0.031,0.018).The median recurrent period in the observation group were 22 and 12 months in the control group,and with singnificant difference (P =0.015).The main side effects were limited to grade Ⅰ or Ⅱ.Conclusions Concurrent TMZ combined with radiotherapy in the treatment of high grade gliomas has better clinical efficacy,and can improve the 2-year and 3-year survival rates.Patients tolerate the strategy well and no severe toxicities are observed.

Objective To observe the effect of EGFR mutation on radiation induced DNA repair in pulmonary adenocarcinoma ceils.Methods A549 cells with wild-type EGFR and H1975 cells with mutated-type of EGFR were irradiated by 4 Gy of 6 MV X-rays.After irradiation,the formation of nuclear γ-H2AX foci was assayed with immunostaining method,the level of DNA-PKcs-EGFR interaction was detected with coimmunoprecipitation,and nuclear RAD51 expression and EGFR nuclear translocation were detected using Western blot.Results DNA repair in the H1975 cells was significantly lower than that in A549 cells.In the irradiated H1975 cells,there was no EGFR translocation with further nuclear DNA-PKcs binding,and the expression of nucleus RAD51 was not altered.But in the irradiated A549 cells,EGFRDNA-PKcs interaction and nucleus RAD51 were increased.Conclusions Lung adenocarcinoma cell line with mutations in the tyrosine kinase domain (TKD) of EGFR exhibits a high radiosensitivity due to the reduction of the non-homologous end-joining (NHEJ) and homologous recombination (HR) DNA DSB repair kinetics.

ObjectiveTo detect the efficacy of compound matrine combined with intensity modulated radiotherapy (IMRT) for patients with locally advanced nasopharyngeal carcinoma (NPC). MethodsA total of 96 patients with locally advanced NPC were randomized into compound matrine combined with IMRT group (the therapeutic group) (n =48) and IMRT group (control group) (n =48). The nasopharyngeal DT and lymph nodes Dr were 66-78 Gy/(33-39 f)in 6-8 weeks,60-70 Gy/(30-35 f)in 6-8 weeks, respectively.The prophylactic dose of neck was 50-54 Gy.ResultsThe NPC efficacy of the therapeutic group was 93.8 ％(45/48)and control group was 79.2 ％(38/48).There was significant difference between the two groups in curative effect (P ＜0.05). The lymph nodes efficacy of the therapeutic group was 87.5 ％ (44/48) and control group was 75.0 ％ (30/48). There was significant difference between the two groups in curative effect (P ＜0.05). The side effects of mucosa were fewer in therapeutic group while the infection rate of pharynx oralis was higher in control group (P ＜0.01). ConclusionCompound matrine combined injection can improve shortterm curative effect of IMRT of locally advanced NPC and significantly decreased side effect of radiotherapy.

Objective To evaluate the technical points and security of CT-guided in percutaneous gold seed fiducials implantation for 132 solid tumors before cyberknife radiosurgery treatment. Methods 132 solid tumors were implanted with gold seed fiducials guided by CT before cyberknife radiosurgery treatment.The complications were analyzed. The methods for the prevention and treatment of the complications were suggested. Results Of 132 cases, the achievement rate of puncture was 99.2%(131/132), including 16 (12.1%) cases of pain in the location of puncture, 10(7.6%) cases of tachycardia, and 6 (4.5%) cases of hypertension. Among the 68 cases of lung cancer, there were 3(4.4%) cases of slight pneumothorax, 3(4.4%)cases of generous pneumothorax. Among the 50 cases of liver cancer, there were 1 (2.0%) case of gold seed fiducials transmigration, 2 (4.0%) cases of small amount bleeding from needle channel. Conclusion Percutaneous gold seed fiducials implantation in CT-guided for solid tumors before cyberknife radiosurgery treatment is a slight trauma and safe method.