Iranian Journal of Radiation Research最新文献_第10页

Demographic characteristics and prognostic factors in pediatric-type sarcomas; A 7 year single institutional experience and comprehensive review of the current literature 小儿型肉瘤的人口学特征及预后因素分析7年的单一机构经验和对当前文献的全面回顾

Iranian Journal of Radiation Research Pub Date : 2018-04-10 DOI: 10.18869/ACADPUB.IJRR.16.2.185

E. Esmati, A. Safaei, H. Nosrati, M. Babaei, M. Lashkari, F. A. Hashemi, F. Farhan, M. Ashtiani, N. Khanjani, A. Alibakhshi

{"title":"Demographic characteristics and prognostic factors in pediatric-type sarcomas; A 7 year single institutional experience and comprehensive review of the current literature","authors":"E. Esmati, A. Safaei, H. Nosrati, M. Babaei, M. Lashkari, F. A. Hashemi, F. Farhan, M. Ashtiani, N. Khanjani, A. Alibakhshi","doi":"10.18869/ACADPUB.IJRR.16.2.185","DOIUrl":"https://doi.org/10.18869/ACADPUB.IJRR.16.2.185","url":null,"abstract":"Background: Due to limited clinical data in pediatric-type sarcomas (rhabdomyosarcoma, Ewing's sarcoma, PNET, and desmoplas c small round-cell tumor), the aim of this study was to evaluate the demographic characteris cs and iden fying prognos c factors for survival. Materials and Methods: We retrospec vely reviewed 110 pa ents with pediatric-type sarcomas. Overall and disease free survival was analyzed with the Kaplan-Meier method and log rank test. To iden fy prognos c factors for overall and disease free survival, mul variate survival analyses using a Cox’s propor onal-hazard regression model was performed. Results: In this study mean age of pa ents were 20.30 years (SD=13.61; range, 1–83 years). The survival data of 54 pa ents (49.1%) were obtained with median survival of 27 months. 3 and 5-year survival rate of these pa ents were 41.5% and 28.3% respec vely. Recurrence of disease (P=0.006) and Ewing sarcoma subtype (P=0.018) were significantly associated with poor overall survival and loca on of the lesion in the upper extremi es (P=0.007) and trunk (P=0.005) were significantly associated with a lower disease free survival. Conclusion: With mul variate analysis, the authors determined that recurrence of disease and Ewing's sarcoma subtype are poor prognos c factors for overall survival and site of origin for disease free survival among pa ents with pediatric-type sarcoma. In addi on, gender, pa ent's age, and size of tumor had no significant impact on overall and disease free survival.","PeriodicalId":14498,"journal":{"name":"Iranian Journal of Radiation Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42417978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Natural radioactivity of some Egyptian materials used in glasses manufacturing and glass ceramics 用于玻璃制造和玻璃陶瓷的一些埃及材料的天然放射性

Iranian Journal of Radiation Research Pub Date : 2018-04-10 DOI: 10.18869/ACADPUB.IJRR.16.2.207

R. Elsaman, G. Ali, M. Uosif, K. Shaaban, Y. Saddeek, K. Aly, K. Chong

{"title":"Natural radioactivity of some Egyptian materials used in glasses manufacturing and glass ceramics","authors":"R. Elsaman, G. Ali, M. Uosif, K. Shaaban, Y. Saddeek, K. Aly, K. Chong","doi":"10.18869/ACADPUB.IJRR.16.2.207","DOIUrl":"https://doi.org/10.18869/ACADPUB.IJRR.16.2.207","url":null,"abstract":"Background: The new glasses from harmful environmental waste such as cement dust; limestone phosphate, sand and borax (Genkare) were manufactured. Investigation of the radioactivity present in these materials (Phosphate rock, cement dust, limestone, sand and borax) enables one to assess any possible radiological hazard to humankind by such materials. Materials and Methods: Fifteen samples were collected from five locations. Activity measurements have been performed by gamma-ray spectrometer, employing a high-resolution scintillation detector NaI (Tl) crystal 3 ×3 inch. In addition, the radiological hazards were calculated for the investigated samples. Results: The average values of activity ranged from 28±2 to 163±12, 2.8±0.7 to 40±3 and from 49±4 to 1337±74 Bq kg-1 for 226R, 232Th and 40K, respectively. The values of absorbed dose rates, radium equivalent activities and annual effective dose due to 226Ra, 232Th and 40K respectively, are ranged from 22.05 to 101.59 nGy h-1, 45.90 to 224.22 Bq kg-1 and 27.04 to 124.59 µSv y-1. In addition, the values of external hazard index, internal hazard index and gamma index have been calculated. Conclusion: According to the obtained results, all materials would not present a significant radiological hazard except phosphate. The results of the study could serve as important baseline radiometric data for future epidemiological studies and monitoring initiatives.","PeriodicalId":14498,"journal":{"name":"Iranian Journal of Radiation Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46251797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Effect of human amnion-derived multipotent progenitor cells on hematopoietic recovery after total body irradiation in C57BL/6 mice 人羊膜源多能祖细胞对C57BL/6小鼠全身照射后造血功能恢复的影响

Iranian Journal of Radiation Research Pub Date : 2018-04-10 DOI: 10.18869/ACADPUB.IJRR.16.2.155

Y. Du, R. Banas, Elizabeth A McCart, Jeffy George, K. Oakley, Y. Han, M. Landauer, R. Day

{"title":"Effect of human amnion-derived multipotent progenitor cells on hematopoietic recovery after total body irradiation in C57BL/6 mice","authors":"Y. Du, R. Banas, Elizabeth A McCart, Jeffy George, K. Oakley, Y. Han, M. Landauer, R. Day","doi":"10.18869/ACADPUB.IJRR.16.2.155","DOIUrl":"https://doi.org/10.18869/ACADPUB.IJRR.16.2.155","url":null,"abstract":"Background: The hematopoie c system is sensi ve to the adverse effects of ionizing radia on. Cellular therapies u lizing mesenchymal stem cells or vascular endothelial cells have been explored as poten al countermeasures for radia on hematopoie c injuries. We inves gated cells cultured from amnion (Amnion-derived Mul potent Progenitor cells, AMPs) for effects on hematopoie c recovery following total body irradia on in mice. Materials and Methods: C57BL/6J mice were sham-irradiated or exposed to 60 Co irradia on (7.75 – 7.90 Gy, 0.6 Gy/min). Either AMPs (5 × 10 6 cells/animal) or vehicle were administered 24 h pos rradia on via intraperitoneal injec on. Results: We observed a 13% and 20% improvement in 30-day survival of mice treated with AMPs compared with treatment with vehicle following irradia on at 7.75 and 7.90 Gy, respec vely. AMP treatment was characterized by a trend toward accelerated recovery of white blood cells, neutrophils, re culocytes, and monocytes, measured through day 40 pos rradia on a9er 7.75 Gy. AMP treatment enhanced hematopoie c cell repopula on of spleen and femoral bone marrow as measured by total nucleated cell and hematopoie c progenitor cell counts in comparison to vehicle-treated animals. FACS analysis showed that AMPs treatment significantly mi gated the reduc on in CD11b + /Gr-1 int and CD11b + /Gr-1 high bone marrow cell popula ons at the nadir, and improved recovery of these cell types. Conclusion: Together, our data indicate that AMPs reduced hematopoie c toxicity induced by ionizing radia on when infused within 24 h a9er radia on injury.","PeriodicalId":14498,"journal":{"name":"Iranian Journal of Radiation Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47240434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Clinical evaluation of simultaneous integrated boost in brain metastasis patients with helical intensity modulated radiotherapy 螺旋调强放疗对脑转移患者同步综合增强的临床评价

Iranian Journal of Radiation Research Pub Date : 2018-04-10 DOI: 10.18869/acadpub.ijrr.16.2.177

A. Mayadağlı, H. Kiziltan, I. K. Celtik, K. Berk, Ertuğrul Tekçe, A. H. Eriş, H. Seyi̇thanoğlu

{"title":"Clinical evaluation of simultaneous integrated boost in brain metastasis patients with helical intensity modulated radiotherapy","authors":"A. Mayadağlı, H. Kiziltan, I. K. Celtik, K. Berk, Ertuğrul Tekçe, A. H. Eriş, H. Seyi̇thanoğlu","doi":"10.18869/acadpub.ijrr.16.2.177","DOIUrl":"https://doi.org/10.18869/acadpub.ijrr.16.2.177","url":null,"abstract":"Brain metastasis is (BM) a signi icant clinical problem in cancer management which occurs on 20 to 45% of all cancer patients (1-2). The primary cancer sites which BM mostly originate from are lung (40-50%) and breast cancer (20-30%) (3). 20-30% of patients with BM have more than 3 metastases, while 70-80% of patients have 1-3 BM (4). The median survival has been observed to be 4-7 months with various fractionation and dose regimens of whole brain radiotherapy (WBRT) (5-6). The treatment of brain metastases is dif icult because of the side effects caused by radiotherapy (RT) and chemotherapy (CT). There is still no signi icant improvement on survival rates despite new treatment schedules (7). Median survival has been observed to be between 2-13 months in new BM treatment schedules (5-6). The primary treatment schedule employed for patients with multiple BM is WBRT either with or without steroids. Surgery and/or radiosurgery, either with or without WBRT was employed for patients with between 1 4 BM sites. With this local and distant brain failure was observed in a substantial number of patients. Two prospective phase III trials have shown a 1-year local and/or distant brain failure ABSTRACT","PeriodicalId":14498,"journal":{"name":"Iranian Journal of Radiation Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43283392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A review on combined biological effects of microwave and other physical or chemical agents 微波与其他物理或化学制剂的联合生物效应综述

Iranian Journal of Radiation Research Pub Date : 2018-04-10 DOI: 10.18869/acadpub.ijrr.16.2.139

S. Tan, H. Wang, R. Peng

{"title":"A review on combined biological effects of microwave and other physical or chemical agents","authors":"S. Tan, H. Wang, R. Peng","doi":"10.18869/acadpub.ijrr.16.2.139","DOIUrl":"https://doi.org/10.18869/acadpub.ijrr.16.2.139","url":null,"abstract":"With the development of science and technology, microwave has been used in many fields such as industry, military, medicine and communica on. People are living in a lapped and dynamic electromagne c environment. Concerns about poten al hazards of microwave are ge ng increasing a en ons. The single biological effects of microwave were widely discussed which was considered harmful. Relevant safety standards had been formulated and applied. However, the real environment was more complex. Microwave was not the only factor that organisms might be affected. Other physical or chemical factors, such as ionizing radia on (IR), ultraviolet (UV), magne c field and chemical drugs, o-en existed with the microwave radia on. Even the microwave itself could create combined exposure situa on, because the environment consisted different frequency microwaves. Nuclear weapons and high-power radar could produce microwave and ionizing radia on. The ultraviolet ray and magne c field generated by the instrument's opera on could act on the human bodies along with the microwaves. The combina on of radiofrequency therapy and chemotherapeu c agents was also commonly used in cancer therapy. Therefore, the combined biological effects of microwaves and other physical or chemical factors were very important. This review had covered the original ar cles in this aspect. In order to be er understand the combined biological effects, the compara ve studies of different frequency microwaves were also included. Differences in biological effects were found among different frequency microwaves, and the combined biological effects contained both hazards and benefits. Findings in combined biological effects were very prac cal for ra onal uses of microwave technologies.","PeriodicalId":14498,"journal":{"name":"Iranian Journal of Radiation Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43575284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimization of prostate cancer radiotherapy using of a spacer gel, volumetric modulated arc therapy and a single biological organ at risk objective 优化前列腺癌放疗使用间隔凝胶，体积调制电弧治疗和单一生物器官的危险目标

Iranian Journal of Radiation Research Pub Date : 2018-04-10 DOI: 10.18869/ACADPUB.IJRR.16.2.169

M. Pinkawa, C. Schubert, N. Escobar-Corral, Vanessa Berneking, M. Eble

{"title":"Optimization of prostate cancer radiotherapy using of a spacer gel, volumetric modulated arc therapy and a single biological organ at risk objective","authors":"M. Pinkawa, C. Schubert, N. Escobar-Corral, Vanessa Berneking, M. Eble","doi":"10.18869/ACADPUB.IJRR.16.2.169","DOIUrl":"https://doi.org/10.18869/ACADPUB.IJRR.16.2.169","url":null,"abstract":"Background: The aim was to evaluate the benefit of technical advances for treatment planning: introduc on of a hydrogel spacer, VMAT (volumetric modulated arc therapy) and a single biological organ at risk objec ve for the rectum and bladder. Ini al standard was a step-and-shoot IMRT (intensity modulated radiotherapy) without a spacer and conven onal organ at risk objec ves. Materials and Methods: Treatment plans were calculated using IMRT and VMAT techniques before and a(er spacer injec on in 27 pa ents, respec vely. Conven onal organ at risk objec ves have been used for the op miza on of IMRT plans, only a single biological organ at risk objec ve for VMAT plans. VMAT vs. IMRT plans and plans before vs. a(er spacer injec on were compared. Results: VMAT plans and independently the spacer demonstrated improved dose homogeneity, whereas VMAT addi onally displayed improved dose conformity. The dose to the bladder and rectum could be significantly decreased applying the VMAT technique (mean rectum volumes of 14%/10%/5% in VMAT vs. 36%/24%/12% in IMRT within the 50Gy/60Gy/70Gy isodoses; p<0.01). NTCP for ≥grade 3 rectum toxicity could be accordingly decreased with the VMAT technique (3.6 vs. 0.9% for IMRT vs. VMAT; p<0.01) and the spacer gel (3.3 vs. 1.2% for plans without vs. with spacer gel; p<0.01) – only 0.3% with VMAT and spacer gel. Conclusion: In addi on to the decreased rectal dose following spacer injec on, VMAT with single biological organ at risk op miza on resulted in further dose reduc on to the organs at risk and improved dose homogeneity and conformity in comparison to the step-and-shoot IMRT technique with conven onal objec ves.","PeriodicalId":14498,"journal":{"name":"Iranian Journal of Radiation Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43088315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Investigation of the effects of a carbon-fiber tabletop on the surface dose and attenuation dose for megavoltage photon beams 碳纤维桌面对超高压光子光束表面剂量和衰减剂量影响的研究

Iranian Journal of Radiation Research Pub Date : 2018-04-10 DOI: 10.18869/ACADPUB.IJRR.16.2.235

G. Gursoy, E. Eser, I. Yigitoglu, H. Koç, F. Kahraman, S. Yamcicier

{"title":"Investigation of the effects of a carbon-fiber tabletop on the surface dose and attenuation dose for megavoltage photon beams","authors":"G. Gursoy, E. Eser, I. Yigitoglu, H. Koç, F. Kahraman, S. Yamcicier","doi":"10.18869/ACADPUB.IJRR.16.2.235","DOIUrl":"https://doi.org/10.18869/ACADPUB.IJRR.16.2.235","url":null,"abstract":"Background: Mul ple beams are generally used with an increased possibility that the beam axis intersects the treatment table. Treatment tabletops are commonly made of carbon fiber due to its high mechanical strength and rigidity, low specific density, extremely light and low radia on beam a enua on proper es. Purpose of this paper is inves gated the dose changes in the buildup region and beam a enua on by a carbon fiber tabletop for high energy 6and 18-MV photon beams. Materials and Methods: Measurements were performed for 10 cm × 10 cm and 20 cm × 20 cm field sizes. The surface dose and percentage depth doses (%DD) were measured by a Markus parallel plate chamber at a source-surface distance (SSD) of 100 cm for 6 MV and 18 MV photon beams. A enua on measurements were made at the solid-water phantom for gantry angles of 0 and 180 rota on of the beam. Results: A carbon fiber tabletop increases the surface dose from 12.87% to 86.65% for 10 cm x 10 cm and from 8.72% to 71.16% for 20 cm × 20 cm field at 6 and 18 MV, respec vely. The surface dose with the carbon fiber tabletop in an open field (0) increases with field size. Conclusion: The carbon fiber tabletop causes a substan ally increased surface dose, and also significantly decreases the skin-sparing effect, which is clinically important. The dosimetric effect of the tabletop may be higher, especially for the intensitymodulated radia on therapy depending on the beam orienta on.","PeriodicalId":14498,"journal":{"name":"Iranian Journal of Radiation Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47952359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

The possibility of hormone-mediated PSA derangement in prostate cancer treatment 激素介导的PSA紊乱在前列腺癌症治疗中的可能性

Iranian Journal of Radiation Research Pub Date : 2018-04-10 DOI: 10.18869/ACADPUB.IJRR.16.2.243

Changro Lee, Junga Lee, Suyong Kim, S. You

{"title":"The possibility of hormone-mediated PSA derangement in prostate cancer treatment","authors":"Changro Lee, Junga Lee, Suyong Kim, S. You","doi":"10.18869/ACADPUB.IJRR.16.2.243","DOIUrl":"https://doi.org/10.18869/ACADPUB.IJRR.16.2.243","url":null,"abstract":"Background: This study was designed to suggest the possibility of hormone-related derangement in salvage radiotherapy (SRT) a er radical prostatectomy in terms of prostate-specific an gen (PSA) control. Materials and Methods: Among 160 consecu ve prostate cancer pa ents who received radical prostatectomy, 34 with SRT between 2004 and 2012 were retrospec vely reviewed. The numbers of pa ents with pathologic T3-T4 stage, Gleason score 8-10, and posi ve resec on margin were 11 (32.4%), 10 (29.4%), and 17 (50.0%), respec vely. Median SRT dose was 64.8 Gy (range, 52.9-70.0 Gy) with 1.8-2.3 Gy frac ona ons. Biochemical failure -free survival a er SRT was counted and the median follow-up period was 32.5 months (range, 10-118 months). Results: A er SRT, the median me for PSA to decrease to less than 0.2 ng/mL was four months (range, 0-25 months). The three-year survival rate was 60.3%. On univariate analysis, preferen al hormone therapy (PHT) (p=0.022), higher PSA at SRT (p=0.005), and higher PSA a er surgery (p=0.003) were related to a shorter biochemical survival period. On mul variate analysis, lower PSA at SRT (p=0.016), higher radia on dose (p=0.007), and non-PHT (p=0.046) suggested a consistent PSA control. Conclusion: According to these results, low PSA values by hormonal interven on need to be reconsidered with a different way to look at the rela onship between the PSA and hormone therapy. SRT should be considered for postopera ve salvage treatment regardless of the hormone-related PSA values.","PeriodicalId":14498,"journal":{"name":"Iranian Journal of Radiation Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45267027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Effect of dose rate on antitumor activity in hypoxic cells by using flattening filter free beams 剂量率对扁平无滤束照射缺氧细胞抗肿瘤活性的影响

Iranian Journal of Radiation Research Pub Date : 2018-03-06 DOI: 10.18869/ACADPUB.IJRR.16.2.197

T. Hara, M. Tominaga, K. Yajyu, Risa Kouzaki, A. Hanyu, H. Yamada, M. Sasaki, S. Azane, Y. Uto

{"title":"Effect of dose rate on antitumor activity in hypoxic cells by using flattening filter free beams","authors":"T. Hara, M. Tominaga, K. Yajyu, Risa Kouzaki, A. Hanyu, H. Yamada, M. Sasaki, S. Azane, Y. Uto","doi":"10.18869/ACADPUB.IJRR.16.2.197","DOIUrl":"https://doi.org/10.18869/ACADPUB.IJRR.16.2.197","url":null,"abstract":"Background: Recently, the Fla ening Filter Free (FFF) beams, which allow a dose rate increase of up to four mes compared to the normal dose rate, have been incorporated into radia on therapy machines. The aim of this study is to evaluate an tumor ac vity in hypoxic cells irradiated with different dose rates using FFF beams and to iden fy the casual mechanism for cellular damage during irradia on. Materials and Methods: EMT6 cells were treated with 95% N2 and 5% CO2 to maintain a hypoxic condi on. Three dose rates, namely, 6.27 Gy/min, 12.00 Gy/ min, and 18.82 Gy/min, were used to deliver the prescribed dose of 2 to 4 Gy using the TrueBeam linear accelerator. The number of colonies was counted to evaluate the cell surviving frac on. To inves gate the mode of ac on, addi onal experiments to detect reac ve oxygen species (ROS) by aminophenyl fluorescein (APF) assay, and DNA double-strand breaks (DSBs) by γH2AX assay were performed. Results: Irradia on of hypoxic cells using FFF beams increases an tumor ac vity as a func on of dose rate. The fluorescence of the APF assay was significantly increased when high dose rates were used. In addi on, results from our γH2AX assays show that the number of DNA DSBs increased as a func on of dose rate, in hypoxic cells. Conclusion: We demonstrate that there is a significant dose rate-dependent difference in an tumor ac vity in hypoxic cells, when FFF","PeriodicalId":14498,"journal":{"name":"Iranian Journal of Radiation Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48235410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Assessment of basic physical and dosimetric parameters of synthetic single-crystal diamond detector and its use in Leksell Gamma Knife and CyberKnife small radiosurgical fields 合成单晶金刚石探测器基本物理和剂量测量参数的评估及其在Leksell伽玛刀和CyberKnife小型放射外科领域的应用

Iranian Journal of Radiation Research Pub Date : 2018-01-15 DOI: 10.18869/ACADPUB.IJRR.16.1.7

T. Veselský, J. Novotný, V. Pastykova

{"title":"Assessment of basic physical and dosimetric parameters of synthetic single-crystal diamond detector and its use in Leksell Gamma Knife and CyberKnife small radiosurgical fields","authors":"T. Veselský, J. Novotný, V. Pastykova","doi":"10.18869/ACADPUB.IJRR.16.1.7","DOIUrl":"https://doi.org/10.18869/ACADPUB.IJRR.16.1.7","url":null,"abstract":"Background: To determine the basic physical and dosimetric proper es of a new synthe c single-crystal diamond detector and its applica on for rela ve small field dosimetry. Materials and Methods: The pre-irradia on dose required to stabilize detector response, dose rate dependence, photon and electron energy dependence, temperature dependence and angular dependence of MicroDiamond detector response were evaluated. Output factors on Leksell Gamma Knife Perfexion and on CyberKnife were measured to assess detector feasibility in small radia on field dosimetry. For all measurements, the detector was connected to Unidos electrometer set to 0 voltage. Results: Rela ve output factors measured on Leksell Gamma Knife Perfexion for 4 mm and 8 mm collimators were in agreement with Monte Carlo reference values from the manufacturer, with devia ons of 0.3% and 2.1%, respec vely. For CyberKnife and fixed circular collimators, the difference in output factor values did not exceed 2% from vendor-supplied values, even for the smallest radia on field with a diameter of 5 mm. Conclusion: Our results indicate that the MicroDiamond detector is a promising tool for rela ve small field dosimetry. For output factor measurements on Leksell Gamma Knife Perfexion and CyberKnife, the detector can be used with minimal response correc ons applied (correc on factors not larger than 2%).","PeriodicalId":14498,"journal":{"name":"Iranian Journal of Radiation Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43420686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2