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Volume 51 (2010)
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- Issue 4 Pages 355-
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- Issue 2 Pages 97-
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Volume 51, Issue 4
Displaying 1-16 of 16 articles from this issue
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Reviews
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Tohru OKADA, Tadashi KAMADA, Hiroshi TSUJI, Jun-etsu MIZOE, Masayuki B ...2010 Volume 51 Issue 4 Pages 355-364
Published: 2010
Released on J-STAGE: July 29, 2010
Advance online publication: May 28, 2010JOURNAL FREE ACCESSIn June 1994, the world's first clinical center offering carbon ion radiotherapy opened at the National Institute of Radiological Science (NIRS), Japan. Among several types of ion species, carbon ions were chosen for cancer therapy because they were judged to have the most optimal properties in terms of superior physical and biological characteristics. As of March 2010, 5,196 patients have been registered for carbon ion radiotherapy. Clinical results have shown that carbon ion radiotherapy has the potential to provide a sufficient radiation dose to the tumor, while having acceptable morbidity in the surrounding normal tissues. Tumors that appear to respond favorably to carbon ions include locally advanced tumors as well as histologically non-squamous cell tumor types such as adenocarcinoma, adenoid cystic carcinoma, malignant melanoma, hepatoma, and bone/soft tissue sarcoma. By taking advantage of the unique properties of carbon ions, treatment with small fractions within a short treatment period has been successfully carried out for a variety of tumors. This means that carbon ion radiotherapy can offer treatment for larger numbers of patients than is possible with other modalities over the same time period.View full abstractDownload PDF (474K) -
Nobuyuki HAMADA, Tatsuhiko IMAOKA, Shin-ichiro MASUNAGA, Toshiyuki OGA ...2010 Volume 51 Issue 4 Pages 365-383
Published: 2010
Released on J-STAGE: July 29, 2010
JOURNAL FREE ACCESSSuperb biological effectiveness and dose conformity represent a rationale for heavy-ion therapy, which has thus far achieved good cancer controllability while sparing critical normal organs. Immediately after irradiation, heavy ions produce dense ionization along their trajectories, cause irreparable clustered DNA damage, and alter cellular ultrastructure. These ions, as a consequence, inactivate cells more effectively with less cell-cycle and oxygen dependence than conventional photons. The modes of heavy ion–induced cell death/inactivation include apoptosis, necrosis, autophagy, premature senescence, accelerated differentiation, delayed reproductive death of progeny cells, and bystander cell death. This paper briefly reviews the current knowledge of the biological aspects of heavy-ion therapy, with emphasis on the authors' recent findings. The topics include (i) repair mechanisms of heavy ion–induced DNA damage, (ii) superior effects of heavy ions on radioresistant tumor cells (intratumor quiescent cell population, TP53-mutated and BCL2-overexpressing tumors), (iii) novel capacity of heavy ions in suppressing cancer metastasis and neoangiogenesis, and (iv) potential of heavy ions to induce secondary (especially breast) cancer.View full abstractDownload PDF (1122K) -
Shinichi MINOHARA, Shigekazu FUKUDA, Nobuyuki KANEMATSU, Yuka TAKEI, T ...2010 Volume 51 Issue 4 Pages 385-392
Published: 2010
Released on J-STAGE: July 29, 2010
JOURNAL FREE ACCESSIn the last few years, hospital-based facilities for carbon-ion radiotherapy are being constructed and proposed in Europe and Asia. During the next few years, several new facilities will be opened for carbon-ion radiotherapy in the world. These facilities in operation or under construction are categorized in two types by the beam shaping method used. One is the passive beam shaping method that is mainly improved and systematized for routine clinical use at HIMAC, Japan. The other method is active beam shaping which is also known as beam scanning adopted at GSI/HIT, Germany. In this paper an overview of some technical aspects for beam shaping is reported. The technique of passive beam shaping is established for stable clinical application and has clinical result of over 4000 patients in HIMAC. In contrast, clinical experience of active beam shaping is about 400 patients, and there is no clinical experience to respiratory moving target. A great advantage of the active beam shaping method is patient-specific collimator-less and compensator-less treatment. This may be an interesting potential for adaptive radiotherapy.View full abstractDownload PDF (683K)
Regular Papers
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Mamta D. NAIDU, James M. MASON, Raymond V. PICA, Hua FUNG, Louis A. PE ...2010 Volume 51 Issue 4 Pages 393-404
Published: 2010
Released on J-STAGE: July 29, 2010
JOURNAL FREE ACCESSSince radiation therapy remains a primary treatment modality for gliomas, the radioresistance of glioma cells and targets to modify their radiation tolerance are of significant interest. Human apurinic endonuclease 1 (Ape1, Ref-1, APEX, HAP1, AP endo) is a multifunctional protein involved in base excision repair of DNA and a redox-dependent transcriptional co-activator. This study investigated whether there is a direct relationship between Ape1 and radioresistance in glioma cells, employing the human U87 and U251 cell lines. U87 is intrinsically more radioresistant than U251, which is partly attributable to more cycling U251 cells found in G2/M, the most radiosensitive cell stage, while more U87 cells are found in S and G1, the more radioresistant cell stages. But observed radioresistance is also related to Ape1 activity. U87 has higher levels of Ape1 than does U251, as assessed by Western blot and enzyme activity assays (~1.5–2 fold higher in cycling cells, and ~10 fold higher at G2/M). A direct relationship was seen in cells transfected with CMV-Ape1 constructs; there was a dose-dependent relationship between increasing Ape1 overexpression and increasing radioresistance. Conversely, knock down by siRNA or by pharmacological down regulation of Ape1 resulted in decreased radioresistance. The inhibitors lucanthone and CRT004876 were employed, the former a thioxanthene previously under clinical evaluation as a radiosensitizer for brain tumors and the latter a more specific Ape1 inhibitor. These data suggest that Ape1 may be a useful target for modifying radiation tolerance.View full abstractDownload PDF (773K) -
Takeki SHIGA, Hiroyuki SUZUKI, Ayumi YAMAMOTO, Hiroaki YAMAMOTO, Kazuo ...2010 Volume 51 Issue 4 Pages 405-415
Published: 2010
Released on J-STAGE: July 29, 2010
Advance online publication: May 13, 2010JOURNAL FREE ACCESSPreviously, we have shown that phenyl hydroquinone, a hepatic metabolite of the Ames test-negative carcinogen o-phenylphenol, efficiently induced aneuploidy in Saccharomyces cerevisiae by arresting the cell cycle at the G2/M transition as a result of the activation of the Hog1 (p38 MAPK homolog)-Swe1 (Wee1 homolog) pathway. In this experiment, we examined the aneuploidy forming effects of hydroquinone, a benzene metabolite, since both phenyl hydroquinone and hydroquinone are Ames-test negative carcinogens and share similar molecular structures. As was seen in phenyl hydroquinone, hydroquinone induced aneuploidy in yeast by delaying the cell cycle at the G2/M transition. Deficiencies in SWE1 and HOG1 abolished the hydroquinone-induced delay at the G2/M transition and aneuploidy formation. Furthermore, Hog1 was phosphorylated by hydroquinone, which may stabilize Swe1. These data indicate that the hydroquinone-induced G2/M transition checkpoint, which is activated by the Hog1-Swe1 pathway, plays a role in the formation of aneuploidy.View full abstractDownload PDF (1122K) -
Akihisa TAKAHASHI, Eiichiro MORI, Xiaoming SU, Yosuke NAKAGAWA, Norito ...2010 Volume 51 Issue 4 Pages 417-422
Published: 2010
Released on J-STAGE: July 29, 2010
Advance online publication: April 24, 2010JOURNAL FREE ACCESSHeating induces histone H2AX phosphorylation at serine 139 (γH2AX). Phosphorylated H2AX subsequently forms foci in numerous mammalian cell lines. The aim of this study was to clarify details in the mechanisms involved in the phosphorylation of H2AX after heating. The cell lines used were DNA-PKcs knockout cells, ATM knockout cells, and their parental cell lines. To elucidate mechanisms of induction of phosphorylation of H2AX after heating, ATM/ATR inhibitor (CGK733) and DNA-PK inhibitor (NU7026) were used. The intensity of γH2AX signals was assayed with flow cytometry. The thermal dose-response curve for the fluorescence intensity of γH2AX appearance in DNA-PKcs–/– cells during the heating period was similar to that observed in DNA-PKcs+/+ cells. On the other hand, the slope of thermal dose-response curve for them in ATM–/– cells was lower than that in ATM+/+ cells. Phosphorylation of H2AX after heating was suppressed by a combination of CGK733 and NU7026 in the culture medium in DNA-PKcs–/– cells, ATM–/– cells and in their parental cells. Although the phosphorylation of H2AX after heating was not suppressed by NU7026 in their parental cells, such phosphorylation was suppressed by CGK733 in their parental cells. These results indicate that ATM is the predominant protein which is active in the phosphorylation of histone H2AX after heating.View full abstractDownload PDF (461K) -
Mitra GHERGHEREHCHI, Hossein AFARIDEH, Mohammad GHANNADI, Ahmad MOHAMM ...2010 Volume 51 Issue 4 Pages 423-430
Published: 2010
Released on J-STAGE: July 29, 2010
JOURNAL FREE ACCESSIn this study, a comparison was made between a plastic scintillator (BC400), a Faraday Cup (FC) and an ionization chamber (IC) used for routine proton dosimetry. Thin scintillators can be applied to proton dosimetry and consequently to proton therapy as relative dosimeters because of their water-equivalent nature, high energy-light conversion efficiency, low dimensions and good proportionality to the absorbed dose at low stopping powers. To employ such scintillators as relative dosimeters in proton therapy, the corrective factors must be applied to correct the quenching luminescence at the Bragg peak. A fine linear proportionality between the luminescence light yield Y and the proton flux in a thin (0.5 mm) scintillator for the 20 and 30 MeV proton beams were observed. The experimental peak/plateau ratios of Bragg Curve for 2, 1 and 0.5 mm scintillators with an accuracy of 0.5% were obtained to be 1.87, 1.91 and 2.30, respectively. With combination of the Markus chamber and the CR-39 detector, the peak/plateau ratio was improved to 3.26. The obtained data of the luminescence yield as a function of the specific energy loss is in agreement with the Craun-Birk's theory. Results show that the FC and Markus ionization chamber are in agreement within 4%, while the FC gives a lower dose evaluation. For a defined beam, the data for the fluence measurements are reproducible within a good accuracy.View full abstractDownload PDF (631K) -
Wan-Ling HSU, Yoshimi TATSUKAWA, Kazuo NERIISHI, Michiko YAMADA, John ...2010 Volume 51 Issue 4 Pages 431-439
Published: 2010
Released on J-STAGE: July 29, 2010
Advance online publication: June 11, 2010JOURNAL FREE ACCESSIn studying the late health effects of atomic-bomb (A-bomb) survivors, earlier findings were that white blood cell (WBC) count increased with radiation dose in cross-sectional studies. However, a persistent effect of radiation on WBC count and other risk factors has yet to be confirmed. The objectives of the present study were 1) to examine the longitudinal relationship between A-bomb radiation dose and WBC and differential WBC counts among A-bomb survivors and 2) to investigate the potential confounding risk factors (such as age at exposure and smoking status) as well as modification of the radiation dose-response. A total of 7,562 A-bomb survivors in Hiroshima and Nagasaki were included in this study from 1964–2004. A linear mixed model was applied using the repeated WBC measurements. During the study period, a secular downward trend of WBC count was observed. Radiation exposure was a significant risk factor for elevated WBC and differential WBC counts over time. A significant increase of WBC counts among survivors with high radiation dose (> 2 Gy) was detected in men exposed below the age of 20 and in women regardless of age at exposure. Effects on WBC of low dose radiation remain unclear, however. Cigarette smoking produced the most pronounced effect on WBC counts and its impact was much larger than that of radiation exposure.View full abstractDownload PDF (589K) -
Khatayut NIGAPRUKE, Patana PUWANICH, Nakorn PHAISANGITTISAKUL, Wiwat Y ...2010 Volume 51 Issue 4 Pages 441-448
Published: 2010
Released on J-STAGE: July 29, 2010
Advance online publication: June 02, 2010JOURNAL FREE ACCESSThis study aims to determine the average absorbed dose of radiation in glandular tissue during mammography and to investigate factors that influence the average glandular dose, particularly the local distribution of glandular tissue within the breast and breast skin thickness. An EGSnrc Monte Carlo code and associated codes were employed in the simulation. The breast voxel models used consist of a homogeneous and heterogeneous mixture of adipose and glandular tissues embedded in a skin layer. The percent depth dose and normalized average glandular dose coefficients for spectra of Mo-Mo target-filter combination were calculated. The results showed good agreement with the experimental results (percent depth dose) and literature values (normalized average glandular dose coefficients) when the breast model is homogeneous. Additional investigation of a heterogeneous breast phantom indicates that the local distribution of glandular tissue within the breast, as well as breast skin thickness, could affect the average glandular dose considerably more than that of a typical homogeneous breast model. This problem may be a concern in most practical situations of breast dosimetry when assessing the radiation risk to patients.View full abstractDownload PDF (361K) -
Takashi UNO, Kouichi ISOBE, Naoyuki UENO, Ataru FUKUDA, Satoshi SUDO, ...2010 Volume 51 Issue 4 Pages 449-454
Published: 2010
Released on J-STAGE: July 29, 2010
Advance online publication: May 28, 2010JOURNAL FREE ACCESSThe objective of this retrospective study was to report initial results of CyberKnife stereotactic radiotherapy (SRT) boost for tumors in the head and neck area. Between March 2008 and August 2009, 10 patients were treated with SRT boost using CyberKnife system due mainly to unfavorable condition such as tumors in close proximity to serial organs or former radiotherapy fields. Treatment sites were the external auditory canal in two, the nasopharynx in one, the oropharynx in three, the nasal cavity in one, the maxillary sinus in two, and the oligometastatic cervical lymph node in one. All patients underwent preceding conventional radiotherapy of 40 to 60 Gy. Dose and fractionation scheme of the Cyberknife SRT boost was individualized, and prescribed dose ranged from 9 Gy to 16 Gy in 3 to 4 fractions. Among four patients for whom dose to the optic pathway was concerned, the maximum dose was only about 3 Gy for three patients whereas 9.6 Gy in the remaining one patient. The maximum dose for the mandible in one of three patients with oropharyngeal cancer was 19.7 Gy, whereas majority of the bone can be spared by using non-isocentric conformal beams. For a patient with nasopharyngeal cancer, the highest dose in the brain stem was 15 Gy. However, majority of the brain stem received less than 40% of the maximum dose. Although a small volume high dose area within the normal structure could be observed in several patients, results of the present study showed potential benefits of the CyberKnife SRT boost.View full abstractDownload PDF (1275K) -
Naoki HAYASHI, Yuta SHIBAMOTO, Yasunori OBATA, Takashi KIMURA, Hisato ...2010 Volume 51 Issue 4 Pages 455-463
Published: 2010
Released on J-STAGE: July 29, 2010
Advance online publication: May 28, 2010JOURNAL FREE ACCESSThe purpose of this study was to evaluate the effect of megavoltage photon beam attenuation (PBA) by couch tops and to propose a method for correction of PBA. Four series of phantom measurements were carried out. First, PBA by the exact couch top (ECT, Varian) and Imaging Couch Top (ICT, BrainLAB) was evaluated using a water-equivalent phantom. Second, PBA by Type-S system (Med-Tec), ECT and ICT was compared with a spherical phantom. Third, percentage depth dose (PDD) after passing through ICT was measured to compare with control data of PDD. Forth, the gantry angle dependency of PBA by ICT was evaluated. Then, an equation for PBA correction was elaborated and correction factors for PBA at isocenter were obtained. Finally, this method was applied to a patient with hepatoma. PBA of perpendicular beams by ICT was 4.7% on average. With the increase in field size, the measured values became higher. PBA by ICT was greater than that by Type-S system and ECT. PBA increased significantly as the angle of incidence increased, ranging from 4.3% at 180° to 11.2% at 120°. Calculated doses obtained by the equation and correction factors agreed quite well with the measured doses between 120° and 180° of angles of incidence. Also in the patient, PBA by ICT was corrected quite well by the equation and correction factors. In conclusion, PBA and its gantry angle dependency by ICT were observed. This simple method using the equation and correction factors appeared useful to correct the isocenter dose when the PBA effect cannot be corrected by a treatment planning system.View full abstractDownload PDF (825K) -
Hitoshi IKUSHIMA, Lei DONG, Jeremy ERASMUS, Pamela ALLEN, Mary F. MCAL ...2010 Volume 51 Issue 4 Pages 465-471
Published: 2010
Released on J-STAGE: July 29, 2010
Advance online publication: May 28, 2010JOURNAL FREE ACCESSThe purpose of this study is to assess predictive value of the positron emission tomography (PET) with 18F-fluoro-deoxyglucose (FDG) for recurrence and survival after radiotherapy (RT) for non-small cell lung cancer (NSCLC). One hundred forty-nine patients underwent pretreatment PET (n = 67) or PET/computed tomography (CT) (n = 82) and definitive RT for NSCLC. We evaluated the relationship between the maximum-pixel standardized uptake value (SUVmax) and clinical tumor features. Univariate Cox proportional hazard analysis (UVA) was used to quantify the risk for local-regional recurrence, distant metastases, and death. Multivariate Cox proportional hazard analysis (MVA) was used to assess the potential independent effect of SUVmax. In the PET group, T1 tumors showed significantly lower SUVmax than T2, T3, and T4 tumors; in the PET/CT group, T1 tumors showed significantly lower SUVmax than T3 and T4 tumors. A high SUVmax was a negative factor for local-regional control (LRC) (p < 0.001), distant metastasis-free survival (DMFS) (p = 0.02), and overall survival (OS) (p = 0.001) on UVA in the PET group. However, the significance decreased to 0.05 for LRC, 0.04 for DMFS, and 0.04 for OS by MVA when tumor size was included in the analysis. A high SUVmax was not a negative factor for LRC, DMFS, or OS on UVA and MVA in the PET/CT group. In conclusion, assessment of predictive value of SUVmax for NSCLC requires consideration of primary tumor size, and the evidence is not sufficient to suggest that FDG uptake in a primary NSCLC provides prognostic information.View full abstractDownload PDF (609K) -
Kan YE, Chen-Bo JI, Xiao-Wei LU, Yu-Hui NI, Chun-Lin GAO, Xiao-Hui CHE ...2010 Volume 51 Issue 4 Pages 473-479
Published: 2010
Released on J-STAGE: July 29, 2010
JOURNAL FREE ACCESSResveratrol, a member of a class of polyphenolic compounds known as flavonols, has been extensively studied for its anticancer, antiviral, anti-inflammatory, and neuroprotective roles. Caenorhabidits elegans is a well-established animal for investigating responses to radiation. We found that resveratrol may provide protection against hazardous radiation. Pre-treatment with resveratrol extended both the maximum and mean life span of irradiated C. elegans. Resveratrol acted as a strong radical scavenger and regulated superoxide dismutase (SOD) expression. In addition, resveratrol was shown to be capable of alleviating γ-ray radiation exposure-induced reduction in mitochondrial SOD expression. Ultimately, a correlation may exist between dietary intake of trace amounts of resveratrol and anti-aging effects. A specific response mechanism may be activated after the administration of resveratrol in irradiated animals. Our results suggest the protective effect of resveratrol is due to its strong ability to protect from oxidative stress and protective effects in mitochondria. Therefore, resveratrol is potentially an effective protecting agent against irradiative damage.View full abstractDownload PDF (649K)
Short Communication
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Takeshi NONOSHITA, Yoshiyuki SHIOYAMA, Katsumasa NAKAMURA, Torahiko NA ...2010 Volume 51 Issue 4 Pages 481-484
Published: 2010
Released on J-STAGE: July 29, 2010
Advance online publication: June 30, 2010JOURNAL FREE ACCESSIn this study, we evaluated the feasibility, efficacy and toxicity of concurrent chemoradiotherapy with S-1 (tegafur-gimeracil-oteracil potassium) for T2N0 glottic carcinoma. A total of 23 patients with T2N0 glottic carcinoma received chemoradiotherapy with S-1. Radiotherapy consisted of five daily fractions of 2 Gy per week, to a total median dose of 70 Gy. S-1 was administered 65 mg/m2 per day for 4 weeks, beginning on the day therapy was started, followed by 2 weeks off the drug and twice a day until the end of radiotherapy. Initial local control rate of the primary tumor was achieved in all patients. The median follow-up period for all patients was 38 months. The 3-year local control rate was 95.4%. Regarding adverse reactions, grade 3 mucositis upon clinical examination, mucositis upon functional/symptomatic examination, dysphagia, hepatic toxicity and anemia were observed in 13, 2, 2, 1 and 1 patients, respectively. This chemoradiotherapy did not result in grade 4 acute toxicity or severe late toxicity. Chemoradiotherapy with S-1 was feasible, well tolerated and effective. This therapy is suggested as a possible regimen for improving local control of T2N0 glottic carcinoma.View full abstractDownload PDF (168K)
Technical Report
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Chul-Young YI, Kook Jin CHUN, Suck-Ho HAH, Hyun-Moon KIM, Chunil LIM2010 Volume 51 Issue 4 Pages 485-492
Published: 2010
Released on J-STAGE: July 29, 2010
Advance online publication: May 27, 2010JOURNAL FREE ACCESSThe dosimetry parameters of the IRH10 192Ir high dose rate brachytherapy source were obtained from the dose calculation formalism recommended in the AAPM Task Group No. 43 report using the Monte Carlo code PENELOPE. The absorbed doses to water and air originating from the photons of the IRH10 192Ir brachytherapy source were calculated by the collision kerma approximation. The dose rate constant was evaluated to be (1.110 ± 0.011) cGy/h U–1. The dose rate per unit air kerma strength around the 192Ir IRH10 brachytherapy source and the anisotropy function were given in tables and figures.View full abstractDownload PDF (1729K)
Miscellaneou
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2010 Volume 51 Issue 4 Pages Cover04_1-Cover04_8
Published: 2010
Released on J-STAGE: July 29, 2010
JOURNAL FREE ACCESSDownload PDF (735K)
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