1.Combined chemo-radiotherapy for inresectable non-small cell lung cancers
Reizhi WANG ; Chunbo WANG ; Rutao GUO
Chinese Journal of Radiation Oncology 2001;10(2):91-93
Objective To evaluate the effect of radiotherapy(RT)combined with chemotherapy(C) for stage Ⅲ non-small-cell lung carcinoma (NSCLC) and to find a more effective way of giving them.Methods From Jan. 1995 to Dec. 1997 , 60 patients with stage Ⅲ NSCLC were randomized into two groups . RT alone group(30 cases) was given conventional fractionated DT 60~70?Gy/6~7 W. The combined group(30 cases) received conventional fractionated radiotherapy plus chemotherapy (DDP,5-FU,VP-16 and IFO, given simulatneosly). In some patients,chemotherapy was also siven before,during and after RT for at least 2 courses. Results CR rates of RT and combined groups were 20% and 43%, respectively . PD rate of the two groups were 10%and 7% . The 1-,2-and 3- year survival rates were 42.4%,15.7%,7.8% in the RT group and 68.1%,37.8%,18.9% in the combined group(P<0.05). The median survival periods were 8 months and 15 months though the combined group had more obvious side-effects than the RT group. Conclusions Combined therapy is able to improve obviously the survival rate of stage Ⅲ NSCLC with the induction therapy very important. We expect a more effective combination is to have RT and C simultaneosly or alternately given.
2.Implementation and development of independent check in radiotherapy
Jiuling SHEN ; Guangjun LI ; Liqin LI ; Fubo LIU ; Sen BAI
Chinese Journal of Radiation Oncology 2017;26(6):715-718
Independent check is one of the key measures of quality control (QC) in radiotherapy and is essential for the assurance of radiotherapy accuracy.In recent years,with the application of computer-aided system,the automaticity of independent check,as well as its accuracy and efficiency,increases.Meanwhile,QC has evolved from a device-centered to a process-centered program.Therefore,independent check has been increasingly systematic and specific.This review gives a brief summary of the implementation and development of independent check.
3.Current status of research on prediction of radiotherapy induced adverse reactions by radiation genomics
Lipin LIU ; Nan BI ; Lyuhua WANG
Chinese Journal of Radiation Oncology 2017;26(6):711-714
The occurrence and severity of radiotherapy-induced adverse events cannot be accounted for or predicted by therapeutic and clinical factors alone.Evidence suggests that genetic variants are associated with adverse effects following radiotherapy.Radiation genomics is the study of genetic variants associated with radiotherapy toxicity.Radiation genomics aims to develop a risk prediction model and uncover the biological mechanisms responsible for radiotherapy toxicity.With the advances in genomics and bioinformatics in the past two decades,radiation genomics has evolved from candidate gene studies to genome-wide association studies,with a series of progress.In this review,we will discuss the study background,design,approaches,challenges,and future directions for radiation genomics.
4.Comparison of whole-body equivalent doses from volumetric modulated arc therapy and static intensity-modulated radiotherapy for cervical cancer
Xiaoqi DONG ; Ge FENG ; Ce YIN ; Na LI ; Mingxuan JIA
Chinese Journal of Radiation Oncology 2017;26(6):667-670
Objective To compare the whole-body equivalent doses from volumetric modulated arc therapy (VMAT) and static intensity-modulated radiotherapy (IMRT) for patients with cervical cancer.Methods Nine patients with cervical cancer admitted to our hospital in 2014 were included in this study.Both VMAT and IMRT were planned for each patient.Each patient's personal dose equivalent (Hp (10)) was measured using thermoluminescent dosimeters placed at the xiphoid process and glabella during IMRT and VMAT.The whole-body equivalent doses were estimated based on the results measured at the xiphoid process and compared between the VMAT and IMRT techniques.The paired t test was used for difference analysis.Results The Hp (10) values measured at the xiphoid process and glabella of every patient were lower for VMAT than for IMRT.At a prescribed dose of 50 Gy,if the mean Hp (10) values measured at the xiphoid process were considered to represent the whole-body equivalent doses,the whole-body equivalent doses for VMAT and IMRT were 364 mSv and 538 mSv,respectively.Conclusions VMAT results in a lower whole-body equivalent dose to patients compared with IMRT.The decreased whole-body equivalent dose delivered by VMAT may reduce the likelihood of a radiation-induced secondary malignancy.
5.Research advances in subventricular zone irradiation in glioblastoma
Chengang WANG ; Yijun LUO ; Minghuan LI ; Jinming YU
Chinese Journal of Radiation Oncology 2017;26(6):702-705
Glioblastoma multiforme (GBM,WHO grade IV) contains some glioma stem cells which have unique self-renewal capacity and multilineage potency.There are numerous neural stem cells in the subventricular zone (SVZ) of adult human brain;it may also act as a storehouse of glioma stem cells that can promote the development and recurrence of a tumor.GBM involving SVZ is prone to early recurrence and intracranial metastasis after resection,so irradiation of the SVZ potentially influences the survival of GBM patients.This review provides a summary of related experimental and clinical studies,and discusses the value of irradiation of the SVZ in GBM patients and the direction of future research.
6.Research advances in proton therapy for pediatric cancer
Xiaoxiao WEN ; Haiou SHI ; Zheng AN
Chinese Journal of Radiation Oncology 2017;26(6):698-701
Pediatric cancer is one of the leading causes of death in children around the world.Although radiotherapy is an important means of treatment for pediatric cancer,it causes acute or chronic adverse events that may affect patients' survival time and quality of life.As a novel and advanced radiation technique,proton therapy allows for precise dose delivery in target volume,significantly reducing the irradiation to surrounding tissues and organs.Studies have shown that proton therapy is well tolerated in the treatment of pediatric cancer,and it achieves good tumor control;proton therapy is superior to traditional radiotherapy in improving quality of life,protecting intelligence,and reducing the risk of secondary cancer.This article reviews the research advances in the application of proton therapy in the treatment of pediatric cancer.
7.Effect of SIRT1 gene silencing on radiosensitivity of diffuse large B-cell lymphoma cells
Yixin KANG ; Shegan GAO ; Yanzhen GUO ; Jun YAO ; Zhiye ZHANG ; Xiaohui GAO ; Dianbao ZHANG ; Shuangshuang GUO ; Lulin ZHANG
Chinese Journal of Radiation Oncology 2017;26(6):687-690
Objective To explore the effect of SIRT1 gene silencing on the radiosensitivity of diffuse large B-cell lymphoma (DLBCL) cells.Methods Immunohistochemistry was used to measure the protein expression of SIRT1 in DLBCL tissues.Western blot was used to measure the expression of SIRT1 in DLBCL cell lines (OCI-Ly3,SU-DHL-2,and SU-DHL-4) and the immortalized B cell line HMy2.CIR.After SU-DHL-4 cells were transfected with si-SIRT1 and si-NC using Lipofectamine 2000,the expression of SIRT1 was determined by Western blot.MTT assay and colony-forming assay were used to assess the cell growth and colony formation ability of SU-DHL-4 cells treated with radiation.The group t-test or univariate analysis of variance was used for comparison between groups.Results The expression rate of SIRT1 in DLBCL tissues was 72.6%(103/140),which was significantly higher than that in reactive lymphoid hyperplasia (RLH) tissues (26.5%,8/25)(P=0.001).The SIRT1 expression was significantly higher in DLBCL cells than in HMy2.CIR cells (P=0.020).After SIRT1 gene silencing by si-SIRT1,the expression of SIRT1 was significantly reduced in SU-DHL-4 cells (P=0.008).Besides,SIRT1 gene silencing significantly reduced the growth rate and colony formation ability of SU-DHL-4 cells treated with radiation (P=0.030).Conclusions SIRT1 gene silencing enhances the radiosensitivity of DLBCL cells,providing a novel target for the radiotherapy of DLBCL.
8.The effects of Celecoxib on human brain microvascular endothelial cells release 6-keto-PGF1α and TXB2 and apoptosis after radiation
Jiaxing SUN ; Xiaoting XU ; Yu TU
Chinese Journal of Radiation Oncology 2017;26(6):682-686
Objective To investigate the effect of Celecoxib on human brain microvascular endothelial cells release6-keto-PGF1α,TXB2 and apotosis after irradiation.Methods The logarithmic growth phase cells were divided into control groups (Con),simple irradiation (IR) groups and combination groups (IR+C).CCK-8 and clone formation experiment were used to evaluate the effects of radiosensitivity and toxicity of celecoxib.The results were observed atthe time point of 6 h,12 h,24 h,48 h after irradiation.ELISA was used to test the contents of 6-keto-PGF1α and TXB2,which metabolized by PGI2 and TXA2 from culture medium after irradiation at different time points in different groups.TXB2/6-keto-PGF1αratios were calculated.Annexin V-FITC/PI double staining method was used to measure the apoptosis rates at different time points in different groups.Western blot was used to measure the protein expression.Paired t test difference.Results Compared with simple irradiation group,there were no significant radiosensitivity (SER=0.96) in combination groups incubated with30 μmol/L of celecoxib.Compared with the control group,the ratio of TXB2/6-keto-PGF1αincreased at each time point in IR and IR+C (P<0.05),and the apoptosis rates increased (P<0.05).Cox-2,P-JNK and Cleaved caspase-3 increased.Compared with IR,the ratio of TXB2/6-keto-PGF1αdecreased at each time point in IR+C (P<0.05),and the apoptosis rates decreased (t=3.34~6.38,P< 0.05).The protein expression of Cox-2,P-JNK and Cleaved caspase-3 decreased.Conclusions Celecoxib may help to protect HBMECs from releasing TXA2 and decreasing the ratio of TXB2/6-keto-PGF1α,and inhibitting apoptosis after irradiation.The mechanisms of apoptosis inhibition may be related to the inhibition of Cox-2 and P-JNK,caspase-3 Cleaved proteinexpressions.
9.Effect of BMI-1 on radiosensitization of esophageal carcino-ma cells after silencing of BMI-1 gene
Xingxiao YANG ; Ming MA ; Heng SONG ; Zhikun LIU ; Shuchai ZHU
Chinese Journal of Radiation Oncology 2017;26(6):671-676
Objective To investigate the effects of BMI-1 expression inhibition by RNA interference on the radiosensitivity of esophageal cancer TE-13 cells and its mechanism.Methods The siRNA based on the sequence of BMI-1 mRNA was synthesized to transfect cultured TE-13 cells as BMI-1 siRNA group,a negative one was synthesized to transfect cultured TE-13 cells as negative control group (NC group),and untransfected TE-13 cells were named as control group.The expression of the BMI-1 mRNA and protein in TE-13 cells was measured by quantitative real-time PCR and Western blot,respectively.The cell proliferation and the radiosensitivity of TE-13 cells were measured by MTS and colony-forming assay,respectively.Flow cytometry was used to analyze cell cycle and apoptosis.The expression of BCL-2 and BAX in TE-13 cells was measured by Western blot.Comparison between groups was made by analysis of variance.Results The BMI-1 siRNA group had significantly lower expression of BMI-1 mRNA and protein than the control group and the NC group (P=0.000,0.000).The proliferation of TE-13 cells in the BMI-1 siRNA group decreased significantly after irradiation (P=0.031).The colony-forming assay showed that the BMI-1 siRNA group had a significantly higher radiosensitivity than the control group and the NC group (P=0.000).After irradiation,the BMI-1 siRNA group had a significantly lower percentage of cells in G2/M phase than the control group and the NC group (P=0.000,0.000).The BMI-1 siRNA group had a significantly increased apoptosis rate (P=0.000,0.000),significantly reduced expression of BCL-2(P=0.000,0.000),and significantly increased expression of BAX after irradiation (P=0.000,0.000).Conclusions BMI-1 siRNA can inhibit the expression of BMI-1 gene in esophageal cancer TE-13 cells,eliminate the cell cycle arrest in G2/M phase,induce cell apoptosis after ionizing irradiation in vitro,and increase the radiosensitivity,which may be related to the regulation of the expression of BCL-2 and BAX.
10.A study of automatic treatment planning based on kernel density estimation
Jiawei FAN ; Jiazhou WANG ; Weigang HU
Chinese Journal of Radiation Oncology 2017;26(6):661-666
Objective To develop an automatic algorithm to predict the dose-volume histogram (DVH) and implement it in clinical practice.Methods Based on the prior information in the existing plan,such as dosimetric results of organs at risk (OARs) and OAR-target spatial relationship,a two-dimensional kernel density estimation was implemented to predict the DVH of OARs.The predicted DVH curves were converted into objective functions that would be implemented in the Pinnacle treatment planning system.Comparisons between predicted and actual values and between Auto-plan and manual planning were made by paired t test.Results We applied this algorithm to 10 rectal cancer patients,10 breast cancer patients,and 10 nasopharyngeal carcinoma patients.The predicted DVH of OARs showed that the deviation between the actual and predicted values at important clinical dose points were within 5%(P>0.05).The re-planning for the 10 breast cancer patients using Auto-plan showed that the heart dose was significantly reduced and the target coverage was increased,which was consistent with the predicted results.Conclusions The method proposed in this study allows for accurat DVH prediction,and,combined with Auto-plan,can be used to generate clinically accepted treatment plans.