Journal of Radiation Research
Online ISSN : 1349-9157
Print ISSN : 0449-3060
Volume 53, Issue 1
Displaying 1-22 of 22 articles from this issue
Review
  • Yuta SHIBAMOTO, Shinya OTSUKA, Hiromitsu IWATA, Chikao SUGIE, Hiroyuki ...
    2012 Volume 53 Issue 1 Pages 1-9
    Published: 2012
    Released on J-STAGE: February 02, 2012
    Advance online publication: October 14, 2011
    JOURNAL FREE ACCESS
    Since the dose delivery pattern in high-precision radiotherapy is different from that in conventional radiation, radiobiological assessment of the physical dose used in stereotactic irradiation and intensity-modulated radiotherapy has become necessary. In these treatments, the daily dose is usually given intermittently over a time longer than that used in conventional radiotherapy. During prolonged radiation delivery, sublethal damage repair takes place, leading to the decreased effect of radiation. This phenomenon is almost universarily observed in vitro. In in vivo tumors, however, this decrease in effect can be counterbalanced by rapid reoxygenation, which has been demonstrated in a laboratory study. Studies on reoxygenation in human tumors are warranted to better evaluate the influence of prolonged radiation delivery. Another issue related to radiosurgery and hypofractionated stereotactic radiotherapy is the mathematical model for dose evaluation and conversion. Many clinicians use the linear-quadratic (LQ) model and biologically effective dose (BED) to estimate the effects of various radiation schedules, but it has been suggested that the LQ model is not applicable to high doses per fraction. Recent experimental studies verified the inadequacy of the LQ model in converting hypofractionated doses into single doses. The LQ model overestimates the effect of high fractional doses of radiation. BED is particularly incorrect when it is used for tumor responses in vivo, since it does not take reoxygenation into account. For normal tissue responses, improved models have been proposed, but, for in vivo tumor responses, the currently available models are not satisfactory, and better ones should be proposed in future studies.
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Biology
  • Lakhan KMA, Feng GAO, Brian L. FISH, John E. MOULDER, Elizabeth R. JAC ...
    2012 Volume 53 Issue 1 Pages 10-17
    Published: 2012
    Released on J-STAGE: February 02, 2012
    JOURNAL FREE ACCESS
    Our long-term goal is to use angiotensin converting enzyme (ACE) inhibitors to mitigate the increase in lung collagen synthesis that is induced by irradiation to the lung, which could result from accidental exposure or radiological terrorism. Rats (WAG/RijCmcr) were given a single dose of 13 Gy (dose rate of 1.43 Gy/min) of X-irradiation to the thorax. Three structurally-different ACE inhibitors, captopril, enalapril and fosinopril were provided in drinking water beginning 1 week after irradiation. Rats that survived acute pneumonitis (at 6–12 weeks) were evaluated monthly for synthesis of lung collagen. Other endpoints included breathing rate, wet to dry lung weight ratio, and analysis of lung structure. Treatment with captopril (145–207 mg/m2/day) or enalapril (19–28 mg/m2/day), but not fosinopril (19–28 mg/m2/day), decreased morbidity from acute pneumonitis. Lung collagen in the surviving irradiated rats was increased over that of controls by 7 months after irradiation. This increase in collagen synthesis was not observed in rats treated with any of the three ACE inhibitors. Analysis of the lung morphology at 7 months supports the efficacy of ACE inhibitors against radiation-induced fibrosis. The effectiveness of fosinopril against fibrosis, but not against acute pneumonitis, suggests that pulmonary fibrosis may not be a simple consequence of injury during acute pneumonitis. In summary, three structurally-different ACE inhibitors mitigate the increase in collagen synthesis 7 months following irradiation of the whole thorax and do so, even when therapy is started one week after irradiation.
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  • Shao-Jie WU, Yu-Jue WANG, Kun-Yuan GUO, Chi CHEN, Tong-Feng ZHAO, Mao- ...
    2012 Volume 53 Issue 1 Pages 18-23
    Published: 2012
    Released on J-STAGE: February 02, 2012
    Advance online publication: December 01, 2011
    JOURNAL FREE ACCESS
    The purpose of this study was to determine the time-dose-effect of total body X-ray irradiation on lymphocytes in lymph nodes and peripheral blood in Tibet minipigs. Forty-eight Tibet minipigs were assigned into 6 groups including 5 experimental groups with 9 and the control group with 3. The minipigs in experimental groups were subjected to a total body X-ray irradiation of 2, 5, 8, 11, and 14 Gy respectively. Lymph nodes and peripheral blood samples were collected at 6, 24, and 72 hours after X-ray exposure and received histological microscopy examination and apoptosis analysis. Histology observation showed that the number of lymphocytes decreased within the lymph nodes with the increase of radiation doses and exposure time. The observation of transmission electron microscopy (TEM) showed typical apoptotic cells below 11 Gy while at 14 Gy necrotic cells were dominant. The apoptotic rate of lymphocytes in the lymph nodes was positively correlated with radiation dose in the range of 2–11 Gy, and reached the maximal level (39.4 ± 2.8) at 24 hours after 11 Gy irradiation, followed by a decrease in the apoptotic rate, but still higher than that of the control group. The number of lymphocytes in the peripheral blood samples was decreased significantly by increasing of the radiation dose and exposure time. We conclude that early damage of lymphocytes by total body X-ray irradiation is dose and time dependent below 11 Gy and before 24 hours post irradiation, and that the dosage of irradiation less than 11 Gy induced apoptosis, whereas the dose at 14 Gy resulted in necrosis in lymphocytes of the lymph nodes.
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  • Chia-Hui LEE, Huang-Meng CHEN, Li-Ke YEH, Meng-Yen HONG, Guewha Steven ...
    2012 Volume 53 Issue 1 Pages 24-32
    Published: 2012
    Released on J-STAGE: February 02, 2012
    JOURNAL FREE ACCESS
    The aim of this work was to explore the molecular mechanisms associated with possible health hazards induced by static magnetic fields (SMFs). Nematodes were grown under SMFs at field strengths from 0 to 200 mT, and the speed of body movement was measured. The effects of exposure to static magnetic fields were observed to be significant in the higher field strength and longer treatment. To explore the possible molecular mechanisms responsible for these effects, semi-quantitative real-time RT-PCR was performed using primers specific to 120 randomly selected genes. Twenty-six differentially expressed genes among apoptosis-, oxidative stress-, and cancer-related genes were identified, indicating that a global molecular response to SMF treatment occurred. The induction of apoptosis was verified by the increase of fluorescence in a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, by the caspase-3 activity assay, and by immunostaining using an antibody against the ced-3 gene product. Mutations in genes involved in major apoptotic pathways, that is, ced-3, ced-4, and ced-9, abolished this SMF-induced behavioral decline; this is consistent with the hypothesis that the apoptosis pathways are involved in the SMF-induced mobility decline. Here we show that long-term and low-dosage exposure to SMF is capable of inducing an apoptosis-mediated behavioral decline in nematodes.
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  • Stéphane GRISON, Jean-Charles MARTIN, Line GRANDCOLAS, Nathalie ...
    2012 Volume 53 Issue 1 Pages 33-43
    Published: 2012
    Released on J-STAGE: February 02, 2012
    JOURNAL FREE ACCESS
    Reports have described apparent biological effects of 137Cs (the most persistent dispersed radionuclide) irradiation in people living in Chernobyl-contaminated territory. The sensitive analytical technology described here should now help assess the relation of this contamination to the observed effects. A rat model chronically exposed to 137Cs through drinking water was developed to identify biomarkers of radiation-induced metabolic disorders, and the biological impact was evaluated by a metabolomic approach that allowed us to detect several hundred metabolites in biofluids and assess their association with disease states. After collection of plasma and urine from contaminated and non-contaminated rats at the end of the 9-months contamination period, analysis with a LC-MS system detected 742 features in urine and 1309 in plasma. Biostatistical discriminant analysis extracted a subset of 26 metabolite signals (2 urinary, 4 plasma non-polar, and 19 plasma polar metabolites) that in combination were able to predict from 68 up to 94% of the contaminated rats, depending on the prediction method used, with a misclassification rate as low as 5.3%. The difference in this metabolic score between the contaminated and non-contaminated rats was highly significant (P = 0.019 after ANOVA cross-validation). In conclusion, our proof-of-principle study demonstrated for the first time the usefulness of a metabolomic approach for addressing biological effects of chronic low-dose contamination. We can conclude that a metabolomic signature discriminated 137Cs-contaminated from control animals in our model. Further validation is nevertheless required together with full annotation of the metabolic indicators.
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  • Yuexia XIE, Jianghong ZHANG, Yanwu XU, Chunlin SHAO
    2012 Volume 53 Issue 1 Pages 44-50
    Published: 2012
    Released on J-STAGE: February 02, 2012
    JOURNAL FREE ACCESS
    Intratumoral hypoxia is an important contributory factor to tumor cell resistance to radiotherapy. SirT1, a nicotinamide adenine dinucleotide (NAD+)-dependent histone/protein deacetylase, has been linked to the decrease of radiation-induced DNA damage and seems to be critical for cancer therapy. The purpose of this study was to investigate the role of SirT1 in hypoxia-induced radiation response on hepatoma cells. It was found that the administration with resveratrol, a putative SirT1 activator, enhanced the resistance of HepG2 cells against radiation-induced DNA damage of MN formation under hypoxia condition; while nicotinamide, a well-known SirT1 inhibitor, sensitized this radiation damage. Nevertheless, pretreatment of cells with 10058-F4, a specific inhibitor of c-Myc, almost eliminated the nicotinamide-induced radiosensitive effect. Further studies revealed that resveratrol inhibited c-Myc protein accumulation via up-regulation of SirT1 expression and deacetylase activity, and this loss of c-Myc protein was abolished by inhibiting its degradation in the presence of MG132, a potent inhibitor of proteasome. In contrast, nicotinamide attenuated c-Myc protein degradation induced by radiation under hypoxia through inhibition of SirT1 deacetylase activity. Our findings suggest that SirT1 could serve as a novel potent target of radiation-induced DNA damage and thus as a potential strategy to advance the efficiency of radiation therapy in hepatoma entities.
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  • Minli WANG, Megumi HADA, Janice HUFF, Janice M. PLUTH, Jennifer ANDERS ...
    2012 Volume 53 Issue 1 Pages 51-57
    Published: 2012
    Released on J-STAGE: February 02, 2012
    JOURNAL FREE ACCESS
    TGFβ is a key modulator of the Epithelial–Mesenchymal Transition (EMT), a process important in cancer progression and metastasis, which leads to the suppression of epithelial genes and expression of mesenchymal proteins. Ionizing radiation was found to specifically induce expression of the TGF-β1 isoform, which can modulate late post-radiation changes and increase the risk of tumor development and metastasis. Interactions between TGFβ induced EMT and DNA damage responses have not been fully elucidated, particularly at low doses and following different radiation quality exposures. Further characterization of the relationship between radiation quality, EMT and cancer development is warranted. We investigated whether space radiation induced TGFβ dependent EMT, using hTERT immortalized human esophageal epithelial cells (EPC2-hTERT) and non-transformed mink lung epithelial cells (Mv1Lu). We have observed morphologic and molecular alterations in EPC2 and Mv1Lu cells consistent with EMT after pre-treatment with TGFβ1. This effect could be efficiently inhibited in both cell lines by the use of a TGFβRI inhibitor. High-energy silicon or iron nuclei were each able to cause a mild induction of EMT, with the inclusion of TGFβ1 inducing a greatly enhanced EMT phenotype even when cells were irradiated with doses as low as 0.1 Gy. A further enhancement of EMT was achieved at a higher dose of 2 Gy. TGFβRI inhibitor was able to reverse the EMT induced by the combination of TGFβ1 and radiation. These studies indicate that heavy ions, even at a low dose, may trigger the process of TGFβ1–induced EMT, and suggest further studies are needed to determine whether the chronic exposures received in space may potentiate this process in astronauts, leading to an increased risk of cancer.
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  • Ayaka HOSOKI, Shin-Ichiro YONEKURA, Qing-Li ZHAO, Zheng-Li WEI, Ichiro ...
    2012 Volume 53 Issue 1 Pages 58-71
    Published: 2012
    Released on J-STAGE: February 02, 2012
    JOURNAL FREE ACCESS
    Reactive oxygen species (ROS) act as a mediator of ionizing radiation-induced cellular damage. Previous studies have indicated that MnSOD (SOD2) plays a critical role in protection against ionizing radiation in mammalian cells. In this study, we constructed two types of stable HeLa cell lines overexpressing SOD2, HeLa S3/SOD2 and T-REx HeLa/SOD2, to elucidate the mechanisms underlying the protection against radiation by SOD2. SOD2 overexpression in mitochondria enhanced the survival of HeLa S3 and T-REx HeLa cells following γ-irradiation. The levels of γH2AX significantly decreased in HeLa S3/SOD2 and T-REx HeLa/SOD2 cells compared with those in the control cells. MitoSoxTM Red assays showed that both lines of SOD2-expressing cells showed suppression of the superoxide generation in mitochondria. Furthermore, flow cytometry with a fluorescent probe (2',7'-dichlorofluorescein) revealed that the cellular levels of ROS increased in HeLa S3 cells during post-irradiation incubation, but the increase was markedly attenuated in HeLa S3/SOD2 cells. DNA microarray analysis revealed that, of 47,000 probe sets analyzed, 117 and 166 probes showed more than 2-fold changes after 5.5 Gy of γ-irradiation in control and HeLa S3/SOD2 cells, respectively. Pathway analysis revealed different expression profiles in irradiated control cells and irradiated SOD2-overexpressing cells. These results indicate that SOD2 protects HeLa cells against cellular effects of γ-rays through suppressing oxidative stress in irradiated cells caused by ROS generated in the mitochondria and through regulating the expression of genes which play a critical role in protection against ionizing radiation.
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  • Xiao-Chun WANG, Li-Li TIAN, Jin TIAN, DeGuan LI, YueYing WANG, HongYin ...
    2012 Volume 53 Issue 1 Pages 72-78
    Published: 2012
    Released on J-STAGE: February 02, 2012
    JOURNAL FREE ACCESS
    Supplementary material
    Purposes The Cks1 protein is a member of the highly conserved family of Cks/Suc1 proteins, which interact with Cdks, and was found to be an essential cofactor for efficient Skp2-dependent ubiquitination of p27. The present study was undertaken to examine the expression status of Cks1 in esophageal squamous cell carcinoma and its significance. Materials and Methods The expression of Cks1 in 140 esophageal squamous cell carcinoma patients was examined by immunohistochemistry. The correlations between Cks1 expression and tumor clinicopathologic features were analyzed. The effects of Cks1 expression on radiotherapy results were also examined. Results In the present study, we found that Cks1 is overexpressed in esophageal squamous cell carcinoma tissues. Elevated expression of Cks1 correlates significantly with tumor stage and positive lymph node metastasis (p < 0.05). Moreover, a significant negative correlation was found between Cks1 expression and the survival of patients who received radiotherapy (p < 0.05). At the molecular level, forced expression of Cks1 promotes the radio-resistance ability of EC9706 cells. Knockdown of Cks1 expression sensitizes cancer cells to radiation, and a wobble mutant of Cks1 that is resistant to Cks1 siRNA can rescue this effect. Conclusions These results demonstrate for the first time that overexpression of Cks1 correlates with the increased radiotherapy resistance of esophageal squamous cell carcinoma.
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  • Mi-Na HONG, Na-Kyung HAN, Hyung-Chul LEE, Young-Kyu KO, Sung-Gil CHI, ...
    2012 Volume 53 Issue 1 Pages 79-86
    Published: 2012
    Released on J-STAGE: February 02, 2012
    JOURNAL FREE ACCESS
    The aim of this study was to determine whether extremely low frequency magnetic fields (ELF-MF) could affect intracellular reactive oxygen species (ROS) levels and antioxidant enzyme activity. After MCF10A human breast epithelial cells were exposed to 1 mT of 60 Hz ELF-MF for 4 hours, intracellular ROS level, superoxide dismutase (SOD) activity, and reduced to oxidized glutathione (GSH/GSSG) ratio were measured. The cells exposed to ELF-MF did not evidence statistically significant changes in the above-mentioned biological parameters as compared to either the incubator controls or sham-exposed cells. By way of contrast, the IR-exposed cells exhibited marked changes in ROS level, SOD activity, and GSH/GSSG ratio. When we assessed morphological changes and senescence-associated beta-galactosidase (SA-β-Gal) activity, only the IR-exposed cells were positive. According to our results, it could be concluded that ELF-MF has no effect on intracellular ROS level, SOD activity, and GSH/GSSG ratio under our exposure condition.
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  • Yukari YOSHIDA, Yoshiyuki SUZUKI, Wael S. AL-JAHDARI, Nobuyuki HAMADA, ...
    2012 Volume 53 Issue 1 Pages 87-92
    Published: 2012
    Released on J-STAGE: February 02, 2012
    JOURNAL FREE ACCESS
    To clarify the relative biological effectiveness (RBE) values of carbon ion (C) beams in normal brain tissues, a rat organotypic slice culture system was used. The cerebellum was dissected from 10-day-old Wistar rats, cut parasagittally into approximately 600-μm-thick slices and cultivated using a membrane-based culture system with a liquid-air interface. Slices were irradiated with 140 kV X-rays and 18.3 MeV/amu C-beams (linear energy transfer = 108 keV/μm). After irradiation, the slices were evaluated histopathologically using hematoxylin and eosin staining, and apoptosis was quantified using the TdT-mediated dUTP-biotin nick-end labeling (TUNEL) assay. Disorganization of the external granule cell layer (EGL) and apoptosis of the external granule cells (EGCs) were induced within 24 h after exposure to doses of more than 5 Gy from C-beams and X-rays. In the early postnatal cerebellum, morphological changes following exposure to C-beams were similar to those following exposure to X-rays. The RBEs values of C-beams using the EGL disorganization and the EGC TUNEL index endpoints ranged from 1.4 to 1.5. This system represents a useful model for assaying the biological effects of radiation on the brain, especially physiological and time-dependent phenomena.
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  • Takuya OKADA, Genro KASHINO, Hideki NISHIURA, Keizo TANO, Masami WATAN ...
    2012 Volume 53 Issue 1 Pages 93-100
    Published: 2012
    Released on J-STAGE: February 02, 2012
    Advance online publication: January 13, 2012
    JOURNAL FREE ACCESS
    X-ray induced formation of micronuclei is generally thought to result from DNA double-strand breaks (DSBs). However, DNA DSBs inhibit the cell cycle progression that is required for micronucleus formation. In order to reconcile this apparent discrepancy, we investigated whether DNA DSBs induced during the G1 phase could lead to micronucleus formation. We irradiated human embryonic (HE17) cells that had been treated with a radical scavenger, either DMSO or ascorbic acid (AsA), and determined the level of suppression of DNA DSBs or micronuclei. When DNA DSBs were evaluated using 53BP1 foci, treatment with 5 mM AsA did not inhibit the numbers of foci at various intervals after X-ray irradiation; however, treatment with 5 mM or 256 mM DMSO did have a significant inhibitory effect. By contrast, an assay of micronucleus numbers showed that treatment with 5 mM or 256 mM DMSO before X-ray irradiation resulted in almost no inhibition of micronucleus formation, but treatment with 5 mM AsA did have a significant inhibitory effect. These results clearly showed that AsA could suppress micronucleus formation, although it was not effective for suppression of DNA DSBs. Therefore, we conclude that DNA DSBs induced in the G1 phase do not directly lead to micronucleus formation.
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  • Bérengère PHULPIN, Nguyen TRAN, Agnès LEROUX, Syl ...
    2012 Volume 53 Issue 1 Pages 101-109
    Published: 2012
    Released on J-STAGE: February 02, 2012
    JOURNAL FREE ACCESS
    Radiotherapy is an integral part of overall cancer therapy. One of the most serious adverse effects of irradiation concern, for long-term survivors, the development of post-radiation sarcoma (PRS) in healthy tissues located within the irradiated area. PRS have bad prognosis and are often detected at a late stage. Therefore, it is obvious that the early detection PRS is a key-point and the development of preclinical models is worthy to evaluate innovative diagnostic and therapeutic procedures. The aim of this study was to develop a spontaneous murin model of PRS and to evaluate the potency of Positron Emission Tomography (PET) for early detection. Fifteen Wistars rats were irradiated unilateraly on the hindlimb with a single dose of 30 Gy. Sequential analysis was based on observational staging recordings, Computerized Tomography (CT) scanning and PET. Tumors were removed and, histopathological and immunochemistry analyses were performed. Among the irradiated rats, 12 sarcomas (80%) were detected. All tumors occurred naturallty within the irradiated hindlimb and were highly aggressive since most tumors (75%) were successfully transplanted and maintained by serial transplantation into nude mice. Upon serial staging recordings, using PET, was found to enable the detection of PRS earlier after irradiation than with the other methods (i.e. 11.9 ± 1.8 vs 12.9 ± 2.6 months). These results confirmed the interest of experimental models of PRS for the preclinical evaluation of innovative diagnostic strategies and confirmed the potency of PET for early detection of PRS. This preclinical model of PRS can also be proposed for the evaluation of therapeutic strategies.
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Oncology
  • Naoko SANUKI, Asami ONO, Eiji KOMATSU, Noritaka KAMEI, Shinji AKAMINE, ...
    2012 Volume 53 Issue 1 Pages 110-116
    Published: 2012
    Released on J-STAGE: February 02, 2012
    JOURNAL FREE ACCESS
    We evaluated associations of interstitial changes with radiation pneumonitis (RP) for patients treated with thoracic radiotherapy. Between 2005 and 2009, patients who received thoracic radiotherapy of 40 Gy or more for lung cancer or thymic tumors and were followed-up for more than 6 months were eligible for this study. Possible risk factors for RP included the presence of interstitial changes on computed tomography before radiotherapy, and elevated C-reactive protein (CRP) and lactate dehydrogenase (LDH) levels; these were compared with the incidences of severe RP. A total of 106 patients were included. The incidences of RP were 4 (4%), 0 (0%), and 5 (5%) for grades 3, 4, and 5, respectively. For those with interstitial changes, the incidence of RP ≥ grade 3 was significantly increased from 3% (2/79) to 26% (7/27) (p < 0.001). CRP and LDH levels were also associated with increased RP, as were pulmonary emphysema and performance status ≥ 2. Among 91 patients with RP ≥ grade 1, RP grade ≥ 3 occurred significantly earlier than grades 1 and 2. In conclusion, pulmonary interstitial changes, LDH and CRP levels, pulmonary emphysema, and performance status ≥ 2 were significantly associated with RP ≥ grade 3. RP grade ≥ 3 occurred significantly earlier than grades 1 and 2. The early appearance of interstitial changes requires careful management due to the possibility of severe RP.
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  • Heng ZHANG, Jin LI, Yue-ying WANG, Ai-min MENG, Qiang LIU, Lei WANG, F ...
    2012 Volume 53 Issue 1 Pages 117-124
    Published: 2012
    Released on J-STAGE: February 02, 2012
    JOURNAL FREE ACCESS
    We performed the study to investigate whether adenovirus-mediated retinoblastoma 94 (RB94) gene transfer could enhance radiation treatment of esophageal squamous cell carcinoma (ESCC) in vitro and in vivo. ESCC cells (Kyse150 cell line) were cultivated in vitro and tumors originated from the cell line were propagated as xenografts in nude mice. Treatment with Ad-RB94 and/or ionizing radiation (IR) was carried out both in vitro and in vivo with Ad-LacZ control vector and blank control. Cell viability, cell cycle distribution, cell apoptosis, tumor growth and transfected gene expression were evaluated and tumor degeneration was analyzed. The data of quantification real-time PCR assays and immunohistochemistry staining using RB antibody indicated that RB94 was efficiently transfected into Kyse150 cells. In vitro, data of cell growth assay indicated that treatment with Ad-RB94 improved radiation treatment of Kyse150 cells. Tumor xenograft studies, pathological analysis of H.E. staining and Ki67 staining suggested transfecting RB94 enhanced tumor regression induced by radiation treatment in vivo. In addition, data of Annexin V, TUNEL and cell cycle distribution assays proposed combination treatment effectively induced cell apoptosis and cell cycle arresting in G2/M phase. In conclusion, transferring RB94 gene by the adenoviral vector enhances radiation treatment of ESCC.
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  • Pei-Liang WANG, Yong-Bo CHENG, Gulina KUERBAN
    2012 Volume 53 Issue 1 Pages 125-129
    Published: 2012
    Released on J-STAGE: February 02, 2012
    JOURNAL FREE ACCESS
    Thrombosis-related edema and lymphedema are two principal types of lower extremity edema results from radiotherapy alone or chemoradiotherapy for patients with cervical cancer. To characterize differences between them, a retrospective study was performed. We collected data including age, race, body weight, FIGO stage, histology type, platelet count, haemoglobin, time of definitely diagnosis, therapeutic regimen, edema type and which leg edema firstly occurred in. Of 40 patients who were eligible for this study, 32 were diagnosed as thrombosis-related edema and 8 diagnosed as lymphedema. The differences in patient age (p = 0.004), propotion of race (p = 0.021), the latent time (p = 0.002) and the mean platelet count (p = 0.019) were statistically significant. Among 32 patients with thrombosis-related edema, 34.4% were in stage II and 53.1% in stage III, 78.1% were squamous cell carcinoma. Among 8 patients with lymphedema, 87.5% were in stage II and 62.5% were squamous cell carcinoma. The differences were not statistically significant for weight (p = 0.94), histology type (p = 0.648), edema site (p = 0.236), haemoglobin (p = 0.088) between the two grouping patients. Although the small patient cohort is a limitation, the results suggest that the patients with thrombosis-related edema may have higher proportion, lower age, shorter latent edema time and more platelet count than those with lymphedema. Also, thrombosis-related edema was likely inclined to Uigur and lymphedema to Han race. We did not find statistical differences in weight, edema site, histology type and haemoglobin between patients with thrombosis-related edema and lymphedema.
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  • Takaharu KUDOH, Hitoshi IKUSHIMA, Eiichi HONDA
    2012 Volume 53 Issue 1 Pages 130-137
    Published: 2012
    Released on J-STAGE: February 02, 2012
    Advance online publication: January 06, 2012
    JOURNAL FREE ACCESS
    A high-dose-rate (HDR) 192-Ir brachytherapy using a customized intraoral mold is effective for superficial oral cavity cancer, and the surrounding normal tissue is kept away from the radioactive source with gauze pads and/or mouth piece for reducing the dose on the normal tissues. In the Tokushima university hospital, the mold has a lead shield which utilizes the space prepared with sufficient border-molding by a specific dental technique using modeling compound. In HDR 192-Ir brachytherapy using a lead shielded customized intraoral mold, there are no reports measuring the absorbed dose. The purpose of the present study is to measure the absorbed dose and discuss the optimum thickness of lead in HDR 192-Ir brachytherapy using a customized intraoral mold with lead shield using a 1 cm thickness mimic mold. The thickness of lead in the mold could be changed by varying the arrangement of 0.1 cm thickness sheet of the acrylic resin plate and lead. The measured doses at the lateral surface of the mold with thermo-luminescence dosimeter were reduced to 1.12, 0.79, 0.57, 0.41, 0.31, 0.24 and 0.19 Gy and the ratios to the prescription dose were reduced to 56, 40, 29, 21, 16, 12 and 10 percent as lead thickness increased from 0 to 0.6 cm in 0.1 cm increments, respectively. A 0.3 cm thickness lead was considered to be required for a 1 cm thickness mold, and it was necessary to thicken the lead as much as possible with the constraint of limited space in the oral cavity, especially at the fornix vestibule.
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  • Hidetoshi SHIMIZU, Shigeru MATSUSHIMA, Yasutomi KINOSADA, Hiroki MIYAM ...
    2012 Volume 53 Issue 1 Pages 138-144
    Published: 2012
    Released on J-STAGE: February 02, 2012
    JOURNAL FREE ACCESS
    Safe imaging modalities are needed for evaluating parotid gland function. The aim of this study was to validate the utility of a magnetic resonance imaging (MRI) tool, equivalent cross-relaxation rate imaging (ECRI), as a measurement of parotid gland function after chemoradiotherapy. Subjects comprised 18 patients with head-neck cancer who underwent ECRI and salivary gland scintigraphy. First, we calculated ECR values (signal intensity on ECRI), maximum uptake rate (MUR) and washout rate (WOR) from salivary gland scintigraphy data at the parotid glands. Second, we investigated correlations between ECR values and each parameter of MUR (uptake function) and WOR (secretory function) obtained by salivary gland scintigraphy at the parotid gland. Next, we investigated each dose-response for ECR, MUR and WOR at the parotid gland. A correlation was detected between ECR values and MUR in both the pre- (r = –0.55, p < 0.01) and post-treatment (r = –0.50, p < 0.05) groups. A significant post-treatment correlation was detected between the percentage change in ECR values at 3–5 months after chemoradiotherapy and median dose to the parotid gland (Pearson correlation, r = –0.62, p < 0.05). However, no correlations were detected between median dose to the parotid gland and either MUR or WOR. ECRI is a new imaging tool for evaluating the uptake function of the parotid gland after chemoradiotherapy.
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Short Communications
  • Yukiko KANEYUKI, Hironori YOSHINO, Ikuo KASHIWAKURA
    2012 Volume 53 Issue 1 Pages 145-150
    Published: 2012
    Released on J-STAGE: February 02, 2012
    JOURNAL FREE ACCESS
    Reactive oxygen species (ROS) can cause significant biological damage and are produced from low linear energy transfer-ionizing radiation, such as X-rays. Although hematopoietic stem cells (HSCs) are known to be particularly sensitive to ionizing radiation, little is known about the roles of mitochondria and ROS production in determining the radiosensitivity of HSCs. The clonogenic survival of CD34+ HSCs, intracellular mitochondrial content, and intracellular ROS production after irradiation were investigated to elucidate the involvement of mitochondria and ROS in the individual radiosensitivity of HSCs detected in human placental/umbilical cord blood. The results showed that large individual differences exist in the initial numbers of each progenitor cell type, as well as in the surviving fraction of cells. When supplemented with an appropriate cytokine combination, a statistically significant increase in ROS production was observed at 3 h after 2 or 4 Gy of irradiation (P < 0.05), with nearly a return to initial levels by 6 h. In contrast, no significant difference was observed under cytokine-free conditions. At this stage, no significant correlations were observed between ROS production, intracellular mitochondrial content, and the surviving fractions of each HSC progenitor. These results suggest that the kinetics of ROS generation during the 6 h after ionizing radiation have little effect on the different radiation sensitivity of HSCs.
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  • Akira SAKUMI, Kenshiro SHIRAISHI, Tsuyoshi ONOE, Kentaro YAMAMOTO, Aki ...
    2012 Volume 53 Issue 1 Pages 151-153
    Published: 2012
    Released on J-STAGE: February 02, 2012
    Advance online publication: January 13, 2012
    JOURNAL FREE ACCESS
    We have successfully created a single arc volumetric modulated arc therapy (VMAT) plan for treating post-surgical left breast/chest wall and regional nodes using Elekta multileaf collimator (MLC). Dose volume histograms (DVHs) were compared between the VMAT plans and conventional tangential beam plans using a field-in-field technique, leading to significant DVH advantages in the VMAT plans. The difference between Elekta VMAT and Varian RapidArc due to different MLC designs was discussed in terms of the number of arcs required to cover a large target, highlighting a single arc capability of Elekta VMAT for a large target volume which may be less sensitive to unexpected organ motion during dose delivery.
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Technical Report
  • Ken YOSHIDA, Mari UEDA, Hideya YAMAZAKI, Tadashi TAKENAKA, Mineo YOSHI ...
    2012 Volume 53 Issue 1 Pages 154-158
    Published: 2012
    Released on J-STAGE: February 02, 2012
    Advance online publication: January 13, 2012
    JOURNAL FREE ACCESS
    To expand the indications for high-dose-rate interstitial brachytherapy (HDR-ISBT) for deep-seated pelvic tumors, we investigated the usefulness of Doppler transrectal ultrasonography (TRUS) guidance and virtual planning. The patient was a 36-year-old female. She had right internal iliac lymph node oligometastasis of vaginal cancer 12 months after radical radiotherapy. The tumor could not be found by gray-scale TRUS and physical examination. Virtual planning was performed using computed tomography with template and vaginal cylinder insertion. We uploaded the images to our treatment planning software and reconstructed the contours of the clinical target volume (CTV) and right internal iliac vessel. Virtual needle applicators were plotted using the template holes for virtual planning. At the time of implantation, Doppler TRUS was used to prevent vessel injury by needle applicators. Applicators were implanted in accordance with virtual planning and Doppler TRUS could detect the right iliac vessel. The percentage of CTV covered by the prescribed dose was 99.8%. The minimum dose received by the maximally irradiated 0.1-cc volume for the right internal iliac vessel was 95% prescribed dose. Complete response was achieved, however, radiological findings showed marginal recurrence at 15 months after HDR-ISBT. Post-radiation neuropathy occurred as a late complication four months after treatment; however, the pain was well controlled by medication. We consider that virtual planning and Doppler TRUS are effective methods in cases where it is difficult to detect the tumor by physical examination and gray-scale TRUS, thereby expanding the indications for ISBT.
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