Objective To investigate the radiosensitivity enhancement on CL187 cancer cell lines after continous low-dose-rate irradiation of 125I seeds blocked by EGFR antibody.Methods There were control group,the irradiation or plus EGFR antibody group,with 3 samples in each group.Clongenic assay was used to detect the survival of cells.The cell cycle distribution and apoptosis were analyzed by flow cytometry.Results The survival fraction of CL187 cells were lower after blocked by EGFR antibody at the same dose irradiation.The SER were 1.34,1.59 and 1.98 when the antibody concentration were 2,5 and 10 nmol/L,respectively.The irradiation plus antibody led to more apoptosis(39.86%±4.38%)of CL187 cells than the irradiation (21.57%±2.97%)plused antibody(12.49%±1.59%)worked alone.Comparison of the low dose rate irradiation related to G2/M cell cycle arrest(46.41%±4.48%),More G1 cell cycle arrest(84.51%±3.42%)walked together along with the EGFR antibody.Conclusions EGFR antibody could enhance the cell radiosensitivity after continuous low-dose-rate.irradiation.The cell cycle redistribution and apoptosis might be the main mechanism of the radiosensitivity enhancement.

Objective To study the effects of 125I seeds irradiation on apoptosis and cell cycle of CL187 colon cancer cells. Methods In vitro cultured human CL187 colon cancer cells were randomly divided into 4 groups:Control group,Irradiation groups under 2,5 and 10 Gy respectively,for which the activity of the seeds was determined at 9.25?104 MBq,and the initial dose to be 2.77 cGy/h.All the cells were collected 48 hours after irradiation.The apoptosis were detected by using double staining method with annexin and propidium iodide(PI),and the cell cycle by using PI staining method. Results The apoptosis rates were 13.74%?1.63%,46.27%?3.82%,32.58%?3.61% respectively in 2 Gy,5 Gy,and 10Gy groups,significantly higher than that of control group(1.67%?0.19%,q=7.594,P

ObjectiveTo evaluate the early response rate and radiation toxicity of cyberknife in the treatment of primary or metastasticretroperitoneal tumors.MethodsTwenty-eightpatientswith retroperitoneal tumors were treated with cyberknife.The total doses were 2000-6000 cGy ( median 4500 cGy) and biological effective doses were 3750-10080 cGy (median 7680 cGy) in 2-10 fractions (median 5).Of all patients,3 received three dimensional conformal radiotherapy (3DCRT) or intensity modulated radiotherapy (IMRT) boost,1 was treated as second-course radiotherapy,and others were treated with cyberknife only.The survival rates were calculated by Kaplan-Meier method and compared with Logrank test.ResultsThe complete response,partial response,stable disease and progression disease rates were 43％(12/28),6％ ( 10/28),18％ ( 5/28 ),4％ ( 1/28 ),respectively.The overall response rate was 96％.The number of patients who were followed up more than 1,2,3 years were 17,9,7,respectively.The 1-,2-and 3-year local control rates were 92％,86％ and 86％,respectively.The 1-,2-and 3-year overall survival rates were 60％,49％ and 49％,respectively.The difference between local progression-free survival and overall survival was not significant ( median 9.5 and 12.0 months,x2 =0.17,P =0.680).Moreover,if the patients did not have metastasis elsewhere and local treatment was effective,there was no significant difference between local progression-free survival and progression free survival (median 17 and 11 months,x2 =0.13,P=0.720).Acute radiation-induced side effects (≥ 2 grade) such as fatigue,anorexia,nausea,vomiting and epigastric discomfort occurred in 9,9,7,7 and 2 patients,respectively.Intestinal stenosis of 1 grade occurred in 1 patient.Conclusions Radiotherapy for retroperitoneal tumors with cyberknife has provided a high response rate with minimal side effects.It is a safe and effective local treatment method for retroperitoneal tumors.

Objective To investigate the influencing factors and predictors for radiation encephalic necrosis after CyberKnife radiotherapy.Methods Ninety-four patients (104 targets) with primary or metastatic intracranial tumors who were treated with CyberKnife radiotherapy from 2006 to 2011 were retrospectively analyzed.All surgeries adopted skull tracking modes with a dose of 12-45 Gy in 1-8 fractions prescribed to 60％-87％ isodose line.Radiation encephalic necrosis was determined by imaging or pathological examination.Logistic regression analysis was used to analyze the relationship between radiation encephalic necrosis and factors including diabetes,cardio-cerebrovascular diseases,target volume,isodose line,prescribed dose,number of fractions,combination with whole-brain irradiation (WBI),and biologically equivalent dose (BED).Predictability and critical threshold of all influencing factors for radiation encephalic necrosis were determined by the receiver operating characteristic (ROC) curve.Results Twelve targets (11.54％) had radiation encephalic necrosis.According to the result of logistic regression analysis,BED,combination with WBI,and number of fractions were influencing factors for radiation encephalic necrosis.In the ROC curves,the areas under curves for the above three factors were 0.892 ± 0.034,0.650± 0.072,and 0.712 ± 0.064,respectively,indicating that only BED can well predict radiation encephalic necrosis after CyberKnife radiotherapy with a dose threshold of ＞ 7410 cGy.Conclusions BED,combination with WBI,and number of fractions are influencing factors for radiation encephalic necrosis.BED is the best predictor of radiation encephalic necrosis with a dose threshold of ＞ 7 410 cGy.

Objective To investigate the value of local progression-free survival (LPFS) for evaluating the local long-term outcome of peripheral lung cancer treated by cyberknife.Methods Retrospective analysis was performed on the clinical records of 81 cyberknife-treated lung cancer patients (90 foci),including 43 primary lung cancer patients (43 foci) and 38 metastatic lung cancer patients (47 foci).Of all the patients,58(63 foci) were treated at a dose of 60 Gy/3 fractions (20 Gy/fraction),and 23 (27 foci) at a dose of 54 Gy/3 fractions (18 Gy/fraction).The short-term treatment outcome and LPFS were used as the indices for observation;a logistic regression was used for analyzing the predictive value of LPFS for local long-term treatment outcome.Results After the evaluation of short-term treatment outcome,63％ of all the foci needed further evaluation.As the follow-up lasted,the number of foci which needed further evaluation decreased,most rapidly during 0.5-2 years after treatment.Re-evaluation results had predictive value for the treatment outcome in the subsequent follow-up,but the predictive value declined as the follow-up lasted.Conclusions LPFS is a recommendable index for evaluating the local outcome of primary or metastatic lung cancer treated by cyberknife,and it also has predicative value for local long-term treatment outcome.

Objective To investigate the impacts of fiducial tracking and X-sight tracking on the short-term therapeutic effect of cybernikife in the treatment of lung cancer.Methods Retrospective analysis was performed on 64 lung cancer patients (72 lesions),including 40 primary tumor patients (41 lesions) and 24 metastatic tumor patients (31 lesions),who were treated with cyberknife.Fiducial tracking was used for 45 lesions,while X-sight tracking was used for 27 lesions.The planning target volume was covered by 70％-94％ (median 80％) isodose contour.The irradiation dose was 60 Gy/3 fractions.The relationship between short-term therapeutic effect and tracking method was determined.Results Overall,the lesions undergoing fiducial tracking showed significantly higher response rate than those undergoing X-sight tracking (93％ vs.74％,x2 =6.84,P=0.033),and so was in lower lung lesions (15％ vs.7％,x2 ＝7.18,P=0.028).But the two tracking methods achieved similar effects in upper lung lesions (28％ vs.12％,x2 =2.36,P =0.310).In the lesions with treatment volumes smaller than 15 cm3,the fiducial tracking achieved significantly higher response rate than the X-sight tracking (25 ％ vs.12％,x2 =6.53,P =0.038),but the two tracking methods achieved similar effects in the lesions with treatment volumes not smaller than 15 cm3 (17％ vs 8％,x2 =1.57,P =0.460).Overall,the lesions undergoing X-sight tracking had significantly highertreatment failure rate than fiducial tracking (1 9 ％ vs.2 ％,x2 =6.33,P =0.021).Conclusions Different tracking methods may lead to different therapeutic effects of cyberknife in the treatment of lung cancer,which are related to lesion location and treatment volume.

Objective To evaluate quantitatively the extra absorbed dose generated by image guided system of the Cyberknife.Methods The exposure parameters and the average frequency of images acquisition during the treatments with G3 Cyberknife in 300 cases with various tumor locations and tracking modes were collected for analysis ;The measurements of the absorbed doses in the phantom with 5 points after single exposure generated by image guided system in various exposure parameters were performed with equipment of phantom CIRS Model 002LFC and 002 PRA with ion chamber PTW30010 included.Based on the data we collected andmeasured,the conclusion of how much extra absorbed dose generated by image guided system of Cyberknife the patients received during Cyberknife treatments was drawn.Results With an average fractions of 3.94(the median was 4),the average exposure frequency was 36.5 times for static tracking per patient per fraction,while it was 49.2 times for dynamic tracking.The experimental results with various exposure parameters,positions and tissue densities showed that the minimum absorbed dose after single exposure was 0.5 μGy,while the maximum was 385 μGy.Conclusions The image guided system of the Cyberknife can induce quite low absorbed dose in patient,while providing all three types of image guided function.

Objective To evaluate the response rate and efficacy of Cyberknife in the treatment of iliac lymph node metastases (ILNM).Methods Twenty-two patients with 27 ILNM were treated by Cyberknife from May 2010 to May 2016.Tumor volume range from 0.88 to 125.66 cm3 (median 18.87 cm3).The total doses ranged from 21 to 51 Gy (median 39 Gy) and biological effective doses from 35.7 to 100 Gy (median 72.6 Gy) in 3-8 fractions (median 5).Sixty-four percent to eighty-two percent (median 72％) isodose line covered planning target.The survival rates were calculated by Kaplan-Meier method and compared with Log-rank test.Results Follow-up time ranged from 8 to 97 months (median 33 months).The complete response,partial response,stable disease and progression disease rates were 37％,48％,7.5％,48％,respectively.In addition,effective rate was 92.5％.Overall survival range from 4 to 68 months (median 21 months).The 1-,2-,3-year local control rate was all 90.6％ and the survival rates were 78.8％,60.6％ and 43.3％,respectively.Adverse reactions after treatment were gastrointestinal reactions such as nausea,vomiting,fatigue.The chemotherapy before Cyberknife helped to improve overall survival.The patients with backache or edema of lower extremity got rapid relief after treatment.Conclusion The treatment of ILNM with Cyberknife has provided a high response rate with minimal side effects.Cyberknife is a safe and effective local treatment method for ILNM.

ObjectiveTo investigate the effectiveness and toxicity of CyberKnife in the treatment of lung metastases.MethodsTreatment details and outcomes were reviewed for 93 targets of 48 histologically verified patients treated by CyberKnife at the CyberKnife Center of Tianjin between September 2006 and June 2010.The median tumor volume was 6.0(0.2 - 135.2) cm3,the median biological equivalent dose was 140.8(53 - 180) cGy (α/β =10),the median fraction was 3(1-7) times and the median isodose line was 81％ (71％-91％ ).ResultsThe rate of follow-up is 96％.33 cases were followed up for more than 2years.The effective rate was 90.3％.Two targets of 2 patients locally progressed.The 1-and 2-year local control rates,overall survival (OS) rates and progression-free survival (PFS) rates were 98％ and 98％,83％ and 63％,and 64％ and 37％,respectively.Univariate analyses showed that age older than 60 versus ≤60 years tended to be predictor for PFS ( x2 =3.45,P =0.063 ) ;The PFS of patients who had single lesion was better than patients with multiple lesions ( x2 =4.49,P =0.034 ) ; patients with disease-free interval longer than 18 months had better OS ( x2 =6.50,P =0.011 ).Five patients were reported to experience treatment-related grade 1 radiation pulmonary injury,and one each for subcutaneous fibrosis with pigmentation,grade 2 and grade 3 adverse event.ConclusionsFor patients with lung metastatic lesion,CyberKnife is an effective option with high local control rate and little acute reaction.The long-term outcome and toxicity need further study.

Objective To investigate the killer cell immunoglobulin-like receptor (KIR) genes, KIR2DS4 and its variant KIR1D for an association with syphilis in the comparison between syphilis patients and unrelated healthy subjects. Methods One hundred and ninety syphilis patients and 192 unrelated healthy subjects were performed to determine the KIR genotypes by PCR-SSP method. The gene frequencies of KIR2DS4 and KIR1D were analyzed for an association with syphilis in the patients and healthy people who belonged to KIR gene haplotype A. Results Of 192 healthy individuals, 187 were identified with a KIR2DS4 gene. And 91 individuals were classified as homozygous haplotype A with the percent of 48.7% (91/187) in 187 KIR2DS4 positive individuals. Of 190 syphilis patients, 181 were identified with a KIR2DS4 gene. And 89 individuals were classified as homozygous haplotype A with the percent of 49.2% (89/181) in 181 KIR2DS4 positive individuals. The frequency of KIR1D/KIR1D in syphilis patients classified as haplotype A was 16.9%, and was significantly higher than that in the control group (6.6%, P=0.032). However, there was no significant difference for the frequencies of KIR2DS4/KIR2DS4 and KIR2DS4/KIR1D between the two groups (P>0.05). Conclusion KIR1D/KIR1D might be associated with syphilis in the comparison between syphilis patients and unrelated healthy controls who were classified as homozygous haplotype A.