Objective To evaluate quality of life in elderly patients treated with iodine-125 radioactive seed implantation for head and neck cancer.Methods From 2005 to 2011,40 elderly patients (≥ 65 years old)with head and neck cancer were treated with brachytherapy of 125I seed implantation alone (without radiation therapy history)and evaluated with QOL-RTI questionnaire for QOL.QOL of them were evaluated and relative factors were analyzed.Results QOL of these patients treated with 125 I-brachytherapy alone was satisfied.QOL in patients with the base tongue cancer was worse than that in others.Age had a significant effect on function/physical QOL and general QOL,but had no significant effect on emotional QOL and socioeconomic QOL.QOL of patients with early stage cancers were better than those with late stage cancers.Pathology,numbers of 125I seeds implanted,and time-period after brachytherapy had no significant effect on QOL.Conclusions QOL of elderly patients with head and neck cancer treated with125 I-BT is good.Tumor volume and clinical staging have significant effects on QOL.

Objective To analyze the influence of tumor volume change on intensity modulated radiotherapy(IMRT)for nasopharyngeal carcinoma by analyzing the repeated CT simulation.Methods Twenty nasopharyngeal carcinoma patients undergoing IMRT from July 2011 to November 2012 were selected in the study.The first CT simulation was conducted prior to radiotherapy,and the repeated CT simulation was finished after radiotherapy of 30 Gy.The first and the repeated CT images were fused in treatment planning system and GTV volume shrink rate was calculated.The original plan was used to recalculate the dose distribution on repeated CT.The dose volume histogram was used to calculate the dose difference of organs at risk including the brain stem and spinal cord.Results Compared with the first CT,GTV volume shrink rate of the repeated CT simulation was 28.7％,the maximum dose,1 cm3 volume and the average dose percentage of the brain stem and spinal cord were increased(t=0.83-3.17,P＜0.05).Conclusions GTV volume shrinked significantly after radiotherapy of 30 Gy in IMRT for nasopharyngeal carcinoma.The dose of the organs at risk increased accordingly.

Objective To evaluate the difference of PC values based on GBZ 97-2002 and on GBZ 97-2009 for lung cancer cases in Chinese uranium miners.Methods Using 19 lung cancer data ascertained in the past epidemiological study,PC values were calculated according to GBZ 97-2002 and GBZ 97-2009.Results In the 19 lung cancer cases,those cases that could not be judged as radiogenic cancers based on GBZ 97-2002,but may be judged as radiogenic cancers with GBZ 97-2009.The probability was enlarged by 1.1 times at least.The major reason was that the used value was the upper limit of 95％ in GBZ 2009 but the median in 2002.Conclusions Compared to GBZ 97-2002,the criteria value of PC in GBZ 97-2009 drops obviously.

Objective To study the angular dependence of four different mammographic dosimeters to monoenergetic X-ray beams and observe the variation tendency in angular dependence to different energy X-rays and to discuss the evaluation of average glandular dose(AGD)in digital breast tomosynthesis(DBT)system.Methods One ionization chamber and three semiconductor dosimeters were exposed by four kinds of beam quality.The signal of each dosimeter was tested over an angular range of 0° to 90°.The dosimeters were exposed for three times at each selected angular position.The measurement at each angle was normalized to the appropriate measurement at perpendicular incidence.Results The responses from all the dosimeters had a maximum at 0° and decreased with increasing angles.When the radiation incidence angle was 10°,the angular dependence were 0.99,0.99,0.96 and 0.96 for dosimeters A,B,C and D,respectively.And the angular dependence decreased to 0.96,1.00,0.78 and 0.52 when the incidence angle was up to 25°.For semiconductor dosimeters,no signal was recorded when incidence angle was beyond 45°.For ionization chamber,the magnitude of the angular dependence generally decreased with increasing energy.Conclusions All of the dosimeters will underestimate the dose if used in DBT.In order to minimize the error due to the rotation angle of X-ray tube,correction factor of mammography dosimeter should be used for the measurement of AGD in DBT systems.

Objective To investigate radiation-induced alternations of phospholipids in epithelial cells,and to provide experimental evidence for understanding the mechanism of radiation-induced intestinal injury.Methods The intestinal epithelial cells(IEC-6)in rats were divided into three groups:normal control group,8 Gy X-ray irradiation group and 12 Gy X-ray irradiation group.Phospholipids were extracted at 6 h or 24 h after radiation and then measured by high-performance liquid chromatography and mass spectrometry(HPLC-MS).Results At 6 h after radiation,the phospholipids in 8 Gy irradiation group didn't vary significantly,while those in 12 Gy irradiation group changed.The PG,PI and Lyso PC were significantly up-regulated(F=5.37,9.60,9.88,P＜0.05).However,at 24 h after radiation,many PE and PG species in both irradiation groups declined(F=5.15-99.77,P＜0.05)and SM species increased in 12 Gy irradiation group(F=4.35-7.92,P＜0.05).Conclusions The ionizing radiation could disorder phospholipid metabolism in IEC-6 cells with a dose-dependent manner.

Objective To explore the effects of silencing Livin gene by RNA interference mediated by lentiviral vector on colorectal cancer HT-29 cell xenograft growth and sensitivity to radiotherapy in nude mice.Methods BALB/c nude mice models were established by subcutaneously inoculating differently treated HT-29 cells into nude mice and the tumor growth situation of tumors was observed by measuring the volume of tumors and the weight of the nude mice at different time points after cell seeding.Livin expression was detected by RT-PCR and immunohistochemistry,respetively.Apoptosis rate was detected by TUNEL.Normal saline,lentivirus carring unrelated sequences,lentivirus caning Livin shRNA were injected intratumorally.All the nude mice were given 10 Gy of 6 MV X-ray irradiation.The changes of mice weight and the tumor volume were measured at different time points and the weight and tumor growth curves were drawn.Results The inhibition rate of tumor volume was(50.04 ± 0.07)％ and the tumor weight of the RNA interfering group was significantly less than that in experimental group compared to the blank and negative groups(F=4.85,P＜0.05),and the inhibition rate of tumor weight was(50.27 ±0.17)％.Relative Livin mRNA expression level in the RNA interfering experimental group was(17.75 ±0.08)％,and was significantly lower than that of the blank group(67.60 ± 0.05)％ and the negative group(68.54 ± 0.03)％(F=89.97,P＜0.01).Livin protein expression level in the RNA inferring group was also significantly lower[(36.00 ± 3.40)％ versus(85.00 ± 3.15)％,(80.33 ± 3.08)％,F=107.32,P＜0.01].The apoptosis rate in the RNA interfering experimental group was significantly higher than that in the blank and the negative groups[(23.67 ± 2.25)％ versus(5.00 ± 1.50)％,(8.33 ± 1.82)％,F=56.94,P＜0.01].Combined with radiotherapy,the tumor volume at different groups had significant difference(F=10.70,P＜0.01),and RNA interfering group was significantly less than negative group and blank group(F=7.01-9.32,P＜0.01).Conclusions Silencing of Livin gene expression by lentiviral vector-mediated RNA interference could inhibit the growth of colorectal HT-29 cell xenograft and increase the sensitivity of the transplanted tumors to radiotherapy.

Objective To investigate the effect of radiation on the expressions of RANKL and OPG in osteoblasts in order to disclose the molecular mechanism of bone injury induced by ionizing radiation.Methods The osteoblasts were differentiated from MC3T3-E1 cells.After 2 or 4 Gy137 Cs γ-irradiation,the mRNA and protein expression levels of RANKL and OPG of osteoblast precursor and osteoblast were detected by real-time PCR and Western blot.Results The expressions of RANKL mRNA (t=5.41,P＜0.05)and protein(t=68.37,P＜0.01)were up-regulated after 4 Gy irradiation,while the expressions of OPG mRNA(t=5.20,7.02,P＜0.05)and protein(t=7.78,9.45,P＜0.05)were down-regulated after 2 and 4 Gy irradiation.Conclusions 2 and 4 Gy ionizing radiation alters RANKL/RANK/OPG pathway in osteoblasts,which may promote the osteoclast differentiation and maturation and hence promote bone resorption of osteoclasts.

Objective To investigate the effect of ionizing radiation on the expression of transcription factor STAT3 target genes in the pulmonary adenocarcinoma cell line A549.Methods The expressions of VEGF,Bcl-2 and Survivin in A549 cells with or without STAT3 inhibition were detected by RT-PCR and/or Western blot 24 h after 2 or 4 Gy of γ-ray irradiation.Results After γ-ray irradiation with 2 or 4 Gy,the expression of VEGF and Survivin increased significantly.However,the expression of Bcl-2 was not affected by γ-ray irradiation.Furthermore,the increased expression of VEGF and Survivin induced by radiation was found to be inhibited after radiation-induced activation of STAT3 was blocked by AG490 inhibiter.Conclusions γ-ray irradiation could up-regulate the expression of Survivin and VEGF via activating STAT3.The increase of Survivin might partly inhibit the radiation-induced apoptosis of A549 cells,and the up-regulation of VEGF might contribute to the tumor angiogenesis.

Objective To explore the radiosensitivity of berberine on esophageal cancer cells under hypoxia condition.Methods MTT assay and clonogenic survival assay were used to evaluate the effect of berberine on proliferation inhibition and radiosensitivity of esophageal cancer cells,respectively.Immunofluorescence was employed to examine the expression of HIF-1.The change of cell cycle distribution and cell apoptosis was assayed by flow cytometry.The expression of HIF-1 was measured by Western blot.DNA damage was detected by γ-H2AX Foci counting.Results With a clear dose and time effect,berberine inhibited cell proliferation and enhanced cell radiosensitivity(t =3.69,P＜0.05)with a sensitizing enhancement ratio(SER)of 1.42.Berberine caused a dose-dependent decrease in HIF-1 protein expression and also significantly increased the cell apoptosis in ECA-109 population(t=4.74,P＜0.05).Compared with the radiation alone group,berberine enhanced X-ray induced DNA double chain breaks(DSB).Conclusions Berberine can increase the radiosensitivity of esophageal cell line ECA-109,which may be associated with decrease of HIF-1 expression and induction of apoptosis in ECA-109 cells.

Objective To compare the dosimetric differences among three-dimensional conformal radiotherapy(3D-CRT),intensity-modulated radiotherapy(IMRT)and RapidArc for prophylactic carnial irradiation(PCI)in small cell lung cancer(SCLC)patients.Methods Ten patients with SCLC were enrolled into this study.3D-CRT,9-field IMRT(IMRT)and double arc RapidArc plans were designed and optimized for each patient.The goal was to deliver 25 Gy to ≥ 95％ of the planning target volume(PTV)while the same normal-tissue dose constraints were achieved.The dose distribution and conformal index (CI),homogeneity index(HI)of target volume,the maximum dose(D2 ％),the minimum dose(D98 ％),target coverage of PTV(V95 and V100),and Dmean and Dmax of organs at risk(OAR)were analyzed by using the dose volume histogram(DVH).The monitor units and delivery time were also evaluated.Results All plans met the clinical requirements.PTV dosimetric parameters(CI,HI,D2％,D98％,V95 and V100)of RapidArc and IMRT were superior to those of 3D-CRT with significant difference(P＜0.05).The maximum doses to the optic nerves,brainstem and the mean dose to the parotid glands of the IMRT and RapidArc plans were all significantly lower than those of the 3D-CRT plan(P＜0.05),while 3D-CRT plan provided the lowest maximum doses and mean dose of the lens and eyes(P＜0.05).Compared with IMRT plan,no obvious advantage in PTV dosimetric parameters could be observed in RapidArc plans.In terms of organ sparing,no statistical difference was observed between IMRT and RapidArc plans.The number of monitor units for 3D-CRT,IMRT and RapidArc were 287.8,1388.8 and 346.6,respectively.Conclusions Compared with 3D-CRT,IMRT and RapidArc show better dosimetric quality.The 3D-CRT plan has a significantly lower dose on the lens and eyes,less MU and shorter delivery time than IMRT and RapidArc plans.