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Sample records for cancer low-dose rate

  1. Low dose irradiation reduces cancer mortality rates

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    Luckey, T.D.

    2000-05-01

    Low doses of ionizing radiation stimulate development, growth, memory, sensual acuity, fecundity, and immunity (Luckey, T.D., ''Radiation Hormesis'', CRC Press, 1991). Increased immune competence reduces cancer mortality rates and provides increased average lifespan in animals. Decreased cancer mortality rates in atom bomb victims who received low dose irradiation makes it desirable to examine populations exposed to low dose irradiation. Studies with over 300,000 workers and 7 million person-years provide a valid comparison of radiation exposed and control unclear workers (Luckey, T.D., Nurture with Ionizing Radiation, Nutrition and Cancer, 34:1-11, 1999). Careful selection of controls eliminated any ''healthy worker effect''. The person-year corrected average indicated the cancer mortality rate of exposed workers was only 51% that of control workers. Lung cancer mortality rates showed a highly significant negative correlation with radon concentrations in 272,000 U.S. homes (Cohen, B.L., Health Physics 68:157-174, 1995). In contrast, radon concentrations showed no effect on hlumg cancer rates in miners from different countries (Lubin, J.H. Am. J. Epidemiology 140:323-332, 1994). This provides evidence that excessive lung cancer in miners is caused by particulates (the major factor) or toxic gases. The relative risk for cancer mortality was 3.7% in 10,000 Taiwanese exposed to low level of radiation from {sup 60}Co in their steel supported homes (Luan, Y.C. et al., Am. Nuclear Soc. Trans. Boston, 1999). This remarkable finding needs further study. A major mechanism for reduced cancer mortality rates is increased immune competence; this includes both cell and humoral components. Low dose irradiation increases circulating lymphocytes. Macrophage and ''natural killer'' cells can destroy altered (cancer) cells before the mass becomes too large. Low dose irradiation also kills suppressor T-cells; this allows

  2. Brachytherapy for early oral tongue cancer. Low dose rate to high dose rate

    International Nuclear Information System (INIS)

    To examine the compatibility of low dose rate (LDR) with high dose rate (HDR) brachytherapy, we reviewed 399 patients with early oral tongue cancer (T1-2N0M0) treated solely by brachytherapy at Osaka University Hospital between 1967 and 1999. For patients in the LDR group (n=341), the treatment sources consisted of Ir-192 pin for 227 patients (1973-1996; irradiated dose, 61-85 Gy; median, 70 Gy), Ra-226 needle for 113 patients (1967-1986; 55-93 Gy; median, 70 Gy). Ra-226 and Ir-192 were combined for one patient. Ir-192 HDR (microSelectron-HDR) was used for 58 patients in the HDR group (1991-present; 48-60 Gy; median, 60 Gy). LDR implantations were performed via oral and HDR via a submental/submandibular approach. The dose rates at the reference point for the LDR group were 0.30 to 0.8 Gy/h, and for the HDR group 1.0 to 3.4 Gy/min. The patients in the HDR group received a total dose of 48-60 Gy (8-10 fractions) during one week. Two fractions were administered per day (at least a 6-h interval). The 3- and 5-year local control rates for patients in the LDR group were 85% and 80%, respectively, and those in the HDR group were both 84%. HDR brachytherapy showed the same lymph-node control rate as did LDR brachytherapy (67% at 5 years). HDR brachytherapy achieved the same locoregional result as did LDR brachytherapy. A converting factor of 0.86 is applicable for HDR in the treatment of early oral tongue cancer. (author)

  3. Brachytherapy for early oral tongue cancer: low dose rate to high dose rate.

    Science.gov (United States)

    Yamazaki, Hideya; Inoue, Takehiro; Yoshida, Ken; Yoshioka, Yasuo; Furukawa, Souhei; Kakimoto, Naoya; Shimizutani, Kimishige; Inoue, Toshihiko

    2003-03-01

    To examine the compatibility of low dose rate (LDR) with high dose rate (HDR) brachytherapy, we reviewed 399 patients with early oral tongue cancer (T1-2N0M0) treated solely by brachytherapy at Osaka University Hospital between 1967 and 1999. For patients in the LDR group (n = 341), the treatment sources consisted of Ir-192 pin for 227 patients (1973-1996; irradiated dose, 61-85 Gy; median, 70 Gy), Ra-226 needle for 113 patients (1967-1986; 55-93 Gy; median, 70 Gy). Ra-226 and Ir-192 were combined for one patient. Ir-192 HDR (microSelectron-HDR) was used for 58 patients in the HDR group (1991-present; 48-60 Gy; median, 60 Gy). LDR implantations were performed via oral and HDR via a submental/submandibular approach. The dose rates at the reference point for the LDR group were 0.30 to 0.8 Gy/h, and for the HDR group 1.0 to 3.4 Gy/min. The patients in the HDR group received a total dose of 48-60 Gy (8-10 fractions) during one week. Two fractions were administered per day (at least a 6-h interval). The 3- and 5-year local control rates for patients in the LDR group were 85% and 80%, respectively, and those in the HDR group were both 84%. HDR brachytherapy showed the same lymph-node control rate as did LDR brachytherapy (67% at 5 years). HDR brachytherapy achieved the same locoregional result as did LDR brachytherapy. A converting factor of 0.86 is applicable for HDR in the treatment of early oral tongue cancer.

  4. Health effect of low dose/low dose rate radiation

    International Nuclear Information System (INIS)

    The clarified and non-clarified scientific knowledge is discussed to consider the cause of confusion of explanation of the title subject. The low dose is defined roughly lower than 200 mGy and low dose rate, 0.05 mGy/min. The health effect is evaluated from 2 aspects of clinical symptom/radiation hazard protection. In the clinical aspect, the effect is classified in physical (early and late) and genetic ones, and is classified in stochastic (no threshold value, TV) and deterministic (with TV) ones from the radioprotection aspect. Although the absence of TV in the carcinogenic and genetic effects has not been proved, ICRP employs the stochastic standpoint from the safety aspect for radioprotection. The lowest human TV known now is 100 mGy, meaning that human deterministic effect would not be generated below this dose. Genetic deterministic effect can be observable only in animal experiments. These facts suggest that the practical risk of exposure to <100 mGy in human is the carcinogenesis. The relationship between carcinogenic risk in A-bomb survivors and their exposed dose are found fitted to the linear no TV model, but the epidemiologic data, because of restriction of subject number analyzed, do not always mean that the model is applicable even below the dose <100 mGy. This would be one of confusing causes in explanation: no carcinogenic risk at <100 mGy or risk linear to dose even at <100 mGy, neither of which is scientifically conclusive at present. Also mentioned is the scarce risk of cancer in residents living in the high background radiation regions in the world in comparison with that in the A-bomb survivors exposed to the chronic or acute low dose/dose rate. Molecular events are explained for the low-dose radiation-induced DNA damage and its repair, gene mutation and chromosome aberration, hypothesis of carcinogenesis by mutation, and non-targeting effect of radiation (bystander effect and gene instability). Further researches to elucidate the low dose

  5. Quality of Life of Oral Cancer Patients After Low-Dose-Rate Interstitial Brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To assess the quality of life (QOL) of oral cancer patients treated with low-dose-rate interstitial brachytherapy (LDR-BT) alone. Methods and Materials: Between June 2005 and July 2006, a total of 56 patients with oral cancer were enrolled in this prospective study. QOL was assessed by means of the core questionnaire and head and neck questionnaire module of the European Organization for Research and Treatment of Cancer (EORTC Quality of Life Questionnaire-Core 30 [QLQ-C30] and QLQ Head and Neck 35 [H and N35]). The questionnaires were distributed to the patients before the start of treatment and 3 months, 6 months, and 12 months after the start of LDR-BT. Results: It was possible to analyze the results for 20 of the initial 56 patients because they did not experience metastasis or recurrence during this study. No functions or symptoms asked about in the QLQ-C30 deteriorated during the first year. The emotional function score steadily and significantly increased. No symptoms in the QLQ-H and N35 significantly deteriorated. The scores for pain, trouble with social eating, and weight loss on the QLQ-H and N35 steadily and significantly decreased. Age, gender, and LDR-BT source had no effect on the change in QOL during the first year, but T-stage significantly affected the change in global health status, tumor site affected the changes in swallowing, sensory problems, sticky saliva, and complications affected the changes in pain, swallowing, and mouth opening. Conclusions: QOL of oral cancer patients treated with LDR-BT is high. However, tumor stage, tumor site, and complications affected the changes in a few functions and symptoms during the first year

  6. Radiation Leukemogenesis at Low Dose Rates

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    Weil, Michael; Ullrich, Robert

    2013-09-25

    The major goals of this program were to study the efficacy of low dose rate radiation exposures for the induction of acute myeloid leukemia (AML) and to characterize the leukemias that are caused by radiation exposures at low dose rate. An irradiator facility was designed and constructed that allows large numbers of mice to be irradiated at low dose rates for protracted periods (up to their life span). To the best of our knowledge this facility is unique in the US and it was subsequently used to study radioprotectors being developed for radiological defense (PLoS One. 7(3), e33044, 2012) and is currently being used to study the role of genetic background in susceptibility to radiation-induced lung cancer. One result of the irradiation was expected; low dose rate exposures are ineffective in inducing AML. However, another result was completely unexpected; the irradiated mice had a very high incidence of hepatocellular carcinoma (HCC), approximately 50%. It was unexpected because acute exposures are ineffective in increasing HCC incidence above background. This is a potential important finding for setting exposure limits because it supports the concept of an 'inverse dose rate effect' for some tumor types. That is, for the development of some tumor types low dose rate exposures carry greater risks than acute exposures.

  7. The OER at low-dose rates

    International Nuclear Information System (INIS)

    There is increasing interest in the treatment of human cancers with multifraction beam therapy at low dose-rates, on the assumption that the OER at low dose-rates is smaller than that at high dose-rates. A comparison has therefore been made of various published values of OER as a function of γ dose-rate for Vicia faba, HeLa cells, P388 cells, hamster cells and chromosome aberrations. The mean value of the OER at low dose-rate was about 20% lower than the mean OER obtained at high dose-rate, although two OER values at low dose-rates were significantly lower than the other reported values. There are technical difficulties associated with maintaining the test systems under hypoxic conditions for long periods of time and the observed decrease in cloning efficiency of hypoxic control cells indicates that cells can be damaged by this treatment alone. It is therefore possible that the high dose-rate OER values would have been reduced if the cells irradiated at high dose-rates under oxic and anoxic conditions had had a pre-treatment period of storage under anoxic conditions. (U.K.)

  8. Lung cancer incidence after exposure of rats to low doses of radon: influence of dose rate

    International Nuclear Information System (INIS)

    To study the effect on lung cancer incidence of a long exposure to low levels of radon, 500 male 3-months-old Sprague-Dawley rats, were exposed to a cumulative dose of 25 WLM of radon and its daughters, 6 hours a day, 5 days a week, during 18 months. Exposure conditions were controlled in order to maintain a defined PAEC: 42 x 106 J.m-3 (2 WL), in the range of domestic and environmental exposures. Animals were kept until they died or given euthanasia when moribund. Mean survival times were similar in both irradiated and control groups: 828 days (SD = 169) and 830 days (SD = 137), as well as lung cancer incidence, 0.60% at 25 WLM and 0.63% for controls. The incidence of lung lesions was compared statistically with controls and those previously obtained at cumulative exposures of 25 and 50 WLM delivered over a 4-6 month period, inducing a significant increase of lung cancer, 2.2% and 3.8% respectively. Such a comparison showed a decreased lung cancer incidence related to a decrease in the dose rate for low levels of radon exposure. (author)

  9. Biological effects of low doses of radiation at low dose rate

    International Nuclear Information System (INIS)

    The purpose of this report was to examine available scientific data and models relevant to the hypothesis that induction of genetic changes and cancers by low doses of ionizing radiation at low dose rate is a stochastic process with no threshold or apparent threshold. Assessment of the effects of higher doses of radiation is based on a wealth of data from both humans and other organisms. 234 refs., 26 figs., 14 tabs

  10. The different biological effects of single, fractionated and continuous low dose rate irradiation on CL187 colorectal cancer cells

    International Nuclear Information System (INIS)

    To determine the biological effectiveness of single, fractionated and continuous low dose rate irradiation on the human colorectal cancer cell line CL187 in vitro and explore the cellular mechanisms. The CL187 cells were exposed to radiation of 6 MV X-ray at a high dose rate of 4Gy/min and 125I seed at a low dose rate of 2.77 cGy/h. Three groups were employed: single dose radiation group (SDR), fractionated dose radiation group (FDR) by 2Gy/f and continuous low dose rate radiation group (CLDR). Four radiation doses 2, 4, 6 and 8Gy were chosen and cells without irradiation as the control. The responses of CL187 cells to distinct modes of radiation were evaluated by the colony-forming assay, cell cycle progression as well as apoptosis analysis. In addition, we detected the expression patterns of DNA-PKcs, Ku70 and Ku80 by Western blotting. The relative biological effect for 125I seeds compared with 6 MV X-ray was 1.42. 48 hrs after 4Gy irradiation, the difference between proportions of cells at G2/M phase of SDR and CLDR groups were statistically significant (p = 0.026), so as the FDR and CLDR groups (p = 0.005). 48 hrs after 4Gy irradiation, the early apoptotic rate of CLDR group was remarkably higher than SDR and FDR groups (CLDR vs. SDR, p = 0.001; CLDR vs. FDR, p = 0.02), whereas the late apoptotic rate of CLDR group increased significantly compared with SDR and FDR group (CLDR vs. SDR, p = 0.004; CLDR vs. FDR, p = 0.007). Moreover, DNA-PKcs and Ku70 expression levels in CLDR-treated cells decreased compared with SDR and FDR groups. Compared with the X-ray high dose rate irradiation, 125I seeds CLDR showed more effective induction of cell apoptosis and G2/M cell cycle arrest. Furthermore, 125I seeds CLDR could impair the DNA repair capability by down-regulating DNA-PKcs and Ku70 expression

  11. Low-dose-rate brachytherapy for patients with transurethral resection before implantation in prostate cancer: long-term results

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    Prada, Pedro J.; Anchuelo, Javier; Blanco, Ana Garcia; Paya, Gema; Cardenal, Juan; Acuña, Enrique; Ferri, Maria [Department of Radiation Oncology, Hospital Universitario Marqués de Valdecilla, Santander, Cantabria (Spain); Vazquez, Andres; Pacheco, Maite; Sanchez, Jesica [Department of Radiation Physics, Hospital Universitario Marqués de Valdecilla, Santander, Cantabria (Spain)

    2016-01-15

    Objectives: We analyzed the long-term oncologic outcome for patients with prostate cancer and transurethral resection who were treated using low-dose-rate (LDR) prostate brachytherapy. Methods and Materials: From January 2001 to December 2005, 57 consecutive patients were treated with clinically localized prostate cancer. No patients received external beam radiation. All of them underwent LDR prostate brachytherapy. Biochemical failure was defined according to the 'Phoenix consensus'. Patients were stratified as low and intermediate risk based on The Memorial Sloan Kettering group definition. Results: The median follow-up time for these 57 patients was 104 months. The overall survival according to Kaplan-Meier estimates was 88% (±6%) at 5 years and 77% (±6%) at 12 years. The 5 and 10 years for failure in tumour-free survival (TFS) was 96% and respectively (±2%), whereas for biochemical control was 94% and respectively (±3%) at 5 and 10 years, 98% (±1%) of patients being free of local recurrence. A patient reported incontinence after treatment (1.7%). The chronic genitourinary complains grade I were 7% and grade II, 10%. At six months 94% of patients reported no change in bowel function. Conclusions: The excellent long-term results and low morbidity presented, as well as the many advantages of prostate brachytherapy over other treatments, demonstrates that brachytherapy is an effective treatment for patients with transurethral resection and clinical organ-confined prostate cancer. (author)

  12. Optimization strategies for pulsed low-dose-rate IMRT of recurrent lung and head and neck cancers.

    Science.gov (United States)

    Kang, Shengwei; Lang, Jinyi; Wang, Pei; Li, Jie; Lin, Muhan; Chen, Xiaoming; Guo, Ming; Chen, Fu; Chen, Lili; Ma, Charlie Ming

    2014-01-01

    Pulsed low-dose-rate radiotherapy (PLDR) has been proven to be a valid method of reirradiation. Previous studies of recurrent cancer radiotherapy were mainly based on conventional 3D CRT and VMAT delivery techniques. There are difficulties in IMRT planning using existing commercial treatment planning systems (TPS) to meet the PLDR protocol. This work focuses on PLDR using ten-field IMRT and a commercial TPS for two specific sites: recurrent lung cancers and head and neck cancers. Our PLDR protocol requires that the maximum dose to the PTV be less than 0.4 Gy and the mean dose to be 0.2 Gy per field. We investigated various planning strategies to meet the PLDR requirements for 20 lung and head and neck patients. The PTV volume for lung cases ranged from 101.7 to 919.4 cm3 and the maximum dose to the PTV ranged from 0.22 to 0.39 Gy. The PTV volume for head and neck cases ranged from 66.2 to 282.1 cm3 and the maximum dose to the PTV ranged from 0.21 to 0.39 Gy. With special beam arrangements and dosimetry parameters, it is feasible to use a commercial TPS to generate quality PLDR IMRT plans for lung and head and neck reirradiation. PMID:24892337

  13. Local Tumor Control and Normal Tissue Toxicity of Pulsed Low-Dose Rate Radiotherapy for Recurrent Lung Cancer

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    Peng Zhang

    2015-05-01

    Full Text Available Objectives: This study investigates (1 local tumor control and (2 normal tissue toxicity of pulsed low-dose rate radiotherapy (PLDR for recurrent lung cancer. Methods: For study 1, nude mice were implanted with A549 tumors and divided into the following 3 groups: (1 control (n = 10, (2 conventional radiotherapy (RT; n = 10, and (3 PLDR (n = 10. Tumor-bearing mice received 2 Gy daily dose for 2 consecutive days. Weekly magnetic resonance imaging was used for tumor growth monitoring. For study 2, 20 mice received 8 Gy total body irradiation either continuously (n = 10 or 40 × 0.2 Gy pulses with 3-minute intervals (n = 10. Results: For study 1, both conventional RT and PLDR significantly inhibited the growth of A549 xenografts compared with the control group (>35% difference in the mean tumor volume; P .05. For study 2, the average weight was 20.94 ± 1.68 g and 25.69 ± 1.27 g and the survival time was 8 days and 12 days for mice treated with conventional RT and PLDR (P < .05, respectively. Conclusion: This study showed that PLDR could control A549 tumors as effectively as conventional RT, and PLDR induced much less normal tissue toxicity than conventional RT. Thus, PLDR would be a good modality for recurrent lung cancers. Advances in Knowledge: This article reports our results of an in vivo animal investigation of PLDR for the treatment of recurrent cancers, which may not be eligible for treatment because of the dose limitations on nearby healthy organs that have been irradiated in previous treatments. This was the first in vivo study to quantify the tumor control and normal tissue toxicities of PLDR using mice with implanted tumors, and our findings provided evidence to support the clinical trials that employ PLDR treatment techniques.

  14. Permanent interstitial low-dose-rate brachytherapy for patients with low risk prostate cancer. An interim analysis of 312 cases

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    Badakhshi, Harun; Graf, Reinhold; Budach, Volker; Wust, Peter [University Hospital Berlin, Department for Radiation Oncology of Charite School of Medicine, Berlin (Germany)

    2015-04-01

    The biochemical relapse-free survival (bRFS) rate after treatment with permanent iodine-125 seed implantation (PSI) or combined seeds and external beam radiotherapy (COMB) for clinical stage T1-T2 localized prostate cancer is a clinically relevant endpoint. The goal of this work was to evaluate the influence of relevant patient- and treatment-related factors. The study population comprised 312 consecutive patients treated with permanent seed implantation. All patients were evaluable for analysis of overall survival (OS) and disease-specific survival (DSS), 230 for bRFS, of which 192 were in the PSI group and 38 in the COMB group. The prescribed minimum peripheral dose was 145 Gy for PSI, for COMB 110 Gy implant and external beam radiotherapy of 45 Gy. The median follow-up time was 33 months (range 8-66 months). bRFS was defined as a serum prostate-specific antigen (PSA) level ≤ 0.2 ng/ml at last follow-up. Overall, the actuarial bRFS at 50 months was 88.4 %. The 50-month bRFS rate for PSI and COMB was 90.9 %, and 77.2 %, respectively. In the univariate analysis, age in the categories ≤ 63 and > 63 years (p < 0.00), PSA nadir (≤ 0.5 ng/ml and > 0.5 ng/ml) and PSA bounce (yes/no) were the significant predicting factors for bRFS. None of the other patient and treatment variables (treatment modality, stage, PSA, Gleason score, risk group, number of risk factors, D90 and various other dose parameters) were found to be a statistically significant predictor of 50-month bRFS. The biochemical failure rates were low in this study. As a proof of principle, our large monocenteric analysis shows that low-dose-rate brachytherapy is an effective and safe procedure for patients with early stage prostate cancer. (orig.) [German] Das biochemisch rezidivfreie Ueberleben (bRFS) nach der Brachytherapie mit permanenter Iod-125-Seed-Implantation (PSI) oder in Kombination mit externer Radiotherapie (COMB) ist beim Patienten mit fruehem Prostatakarzinom (T1/T2) ein relevanter

  15. The OER at low dose-rates

    International Nuclear Information System (INIS)

    The author comments on a letter (Kal, H.B., and Barendsen, G.W., 1976, Br. J. Radiol., vol. 49, 1049) reviewing published values of the OER for low dose-rate γ-rays. Artefacts of the system may have been responsible for one very low OER value taken from work carried out in the early 1960s, but later work in which these problems were eliminated still yielded OER values significantly lower than for acute X- or γ-ray exposures. Consideration is given to significance of this reduction in OER for γ-rays at the low dose-rates characteristic of interstitial implants. The performance of these interstitial implants may be comparable with the most sophisticated and expensive pion or heavy ion treatments. (U.K.)

  16. Mortality risk coefficients for radiation-induced cancer at high doses and dose-rates, and extrapolation to the low dose domain.

    Science.gov (United States)

    Liniecki, J

    1989-01-01

    Risk coefficients for life-long excessive mortality due to radiation-induced cancers are presented, as derived in 1988 by the U.N. Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), principally on the basis of follow-up from A-bomb survivors in Japan, over the period from 1950 through 1985. The data are based on the new, revised dosimetry (DS 86) in the two cities, and reflect the effects of high and intermediate doses of basically low LET radiation delivered instantaneously. The author presents arguments relevant to the extrapolation of the risk to the low dose (dose rate) domain, as outlined by UNSCEAR in its 1986, and the NCRP (USA) in its 1980, (no 64), reports. The arguments are based on models and dose-response relationships for radiation action, derived from data on cellular radiobiology, animal experiments on radiation-induced cancers and life shortening, as well as the available limited human epidemiological evidence. The available information points to the lower effectiveness of sparsely ionizing radiation at low doses and low dose-rates, as compared with that observed for high, acutely delivered doses. The possible range of the reduction values (DREF) is presented. For high LET radiations, the evidence is less extensive and sometimes contradictory; however, it does not point to a reduction of the effectiveness at low doses/dose-rates, relative to the high dose domain. Practical consequences of these facts are considered. PMID:2489419

  17. Assessment of the expected harm from prenatal irradiation with low doses and low dose rates

    International Nuclear Information System (INIS)

    The validity of the coefficients, suggested by ICRP (Publication 45) for assessment of the risk from prenatal irradiation with low doses and low dose rates is discussed. This includes: development of lethal and curable cancer, severe genetic defects, death before implantation and retarded mental development. Summarizing the individual assessment, the total harm from prenatal irradiation with 1 mvSv have been estimated at 4,9.104 lost years. The expected harm from the additional irradiation of the Bulgarian population during the first year after the Chernobyl accident is evaluated on that basis, taking into account the number of expected pregnancies among Bulgarian women in reproductive age and the individual effective equivalent doses. 15 refs

  18. Advanced Computational Approaches for Characterizing Stochastic Cellular Responses to Low Dose, Low Dose Rate Exposures

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    Scott, Bobby, R., Ph.D.

    2003-06-27

    applications of NEOTRANS2, indicate that nonlinear threshold-type, dose-response relationships for excess stochastic effects (problematic nonlethal mutations, neoplastic transformation) should be expected after exposure to low linear energy transfer (LET) gamma rays or gamma rays in combination with high-LET alpha radiation. Similar thresholds are expected for low-dose-rate low-LET beta irradiation. We attribute the thresholds to low-dose, low-LET radiation induced protection against spontaneous mutations and neoplastic transformations. The protection is presumed mainly to involve selective elimination of problematic cells via apoptosis. Low-dose, low-LET radiation is presumed to trigger wide-area cell signaling, which in turn leads to problematic bystander cells (e.g., mutants, neoplastically transformed cells) selectively undergoing apoptosis. Thus, this protective bystander effect leads to selective elimination of problematic cells (a tissue cleansing process in vivo). However, this protective bystander effects is a different process from low-dose stimulation of the immune system. Low-dose, low-LET radiation stimulation of the immune system may explain why thresholds for inducing excess cancer appear much larger (possibly more than 100-fold larger) than thresholds for inducing excess mutations and neoplastic transformations, when the dose rate is low. For ionizing radiation, the current risk assessment paradigm is such that the relative risk (RR) is always ¡Ý 1, no matter how small the dose. Our research results indicate that for low-dose or low-dose-rate, low-LET irradiation, RR < 1 may be more the rule than the exception. Directly tied to the current RR paradigm are the billion-dollar cleanup costs for radionuclide-contaminated DOE sites. Our research results suggest that continued use of the current RR paradigm for which RR ¡Ý 1 could cause more harm than benefit to society (e.g., by spreading unwarranted fear about phantom excess risks associated with low-dose low

  19. DNA repair and damage pathway related cancer suppressor genes in low-dose-rate irradiated AKR/J an IR mice

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    Bang, Hyun Soon; Bong, Jin Jong; Kang, Yumi; Choi, Moo Hyun; Lee, Hae Un; Yoo, Jae Young; Choi, Seung Jin; Kim, Hee Sun [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd, Gyeongju (Korea, Republic of); Lee, Kyung Mi [Global Research Lab, BAERI Institute, Dept. of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul (Korea, Republic of)

    2012-11-15

    It has been reported that low-dose-rate radiation stimulates the immune response, prolongs life span and inhibits carcinogenesis. The high dose-rate radiation influences the expression of DNA repair and damage-related genes. In contrast, DNA repair and damage signaling triggered by low-dose-rate irradiation remain unclear. In the present study, we investigated the differential expression of DNA repair and damage pathway related genes in the thymus of AKR/J and ICR mice after 100th day low-dose-rate irradiation. Our findings demonstrated that low-dose-rate γ -radiation suppressed tumorigenesis.

  20. Ameliorative effects of low dose/low dose-rate irradiation on reactive oxygen species-related diseases model mice

    International Nuclear Information System (INIS)

    β-cells against superoxide generated by glycation reaction evoked by high glucose environment. Continuous irradiation at 0.63 mGy/hr from 28 days of age elongates life span, and recovers splenic inflammatory response in Klotho-mice bearing ageing syndrome. The radiation increases anti-oxidants in liver, implicating the prevention of ageing through the suppression of cellular oxidative damages. Our results suggest that low dose/low dose-rate radiation effectively ameliorates diseases related to reactive oxygen species, and elongates life span of animals, at least in part through the stimulation of protective responses against oxidative stress. These findings are important not only for clinical use of low dose/low dose-rate radiation for human diseases, but also for non-cancerous risk estimation at dose and dose rate range argued in legal restrictions. (author)

  1. Incidence of Second Malignancies in Prostate Cancer Patients Treated With Low-Dose-Rate Brachytherapy and Radical Prostatectomy

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    Hamilton, Sarah Nicole; Tyldesley, Scott [Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia (Canada); Department of Radiation Oncology, British Columbia Cancer Agency–Vancouver Centre, Vancouver, British Columbia (Canada); Hamm, Jeremy [Department of Population Oncology, British Columbia Cancer Agency–Vancouver Centre, Vancouver, British Columbia (Canada); Jiang, Wei Ning [Faculty of Medicine, University of British Columbia, Vancouver, British Columbia (Canada); Keyes, Mira; Pickles, Tom [Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia (Canada); Department of Radiation Oncology, British Columbia Cancer Agency–Vancouver Centre, Vancouver, British Columbia (Canada); Lapointe, Vince [Department of Medical Physics, British Columbia Cancer Agency–Vancouver Centre, Vancouver, British Columbia (Canada); Kahnamelli, Adam [Department of Radiation Oncology, British Columbia Cancer Agency–Vancouver Centre, Vancouver, British Columbia (Canada); McKenzie, Michael [Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia (Canada); Department of Radiation Oncology, British Columbia Cancer Agency–Vancouver Centre, Vancouver, British Columbia (Canada); Miller, Stacy [Department of Radiation Oncology, British Columbia Cancer Agency–Centre for the North, Prince George, British Columbia (Canada); Morris, W. James, E-mail: jmorris@bccancer.bc.ca [Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia (Canada); Department of Radiation Oncology, British Columbia Cancer Agency–Vancouver Centre, Vancouver, British Columbia (Canada)

    2014-11-15

    Purpose: To compare the second malignancy incidence in prostate cancer patients treated with brachytherapy (BT) relative to radical prostatectomy (RP) and to compare both groups with the cancer incidence in the general population. Methods and Materials: From 1998 to 2010, 2418 patients were treated with Iodine 125 prostate BT monotherapy at the British Columbia Cancer Agency, and 4015 referred patients were treated with RP. Cancer incidence was compared with the age-matched general population using standardized incidence ratios (SIRs). Pelvic malignancies included invasive and noninvasive bladder cancer and rectal cancer. Cox multivariable analysis was performed with adjustment for covariates to determine whether treatment (RP vs BT) was associated with second malignancy risk. Results: The median age at BT was 66 years and at RP 62 years. The SIR comparing BT patients with the general population was 1.06 (95% confidence interval [CI] 0.91-1.22) for second malignancy and was 1.53 (95% CI 1.12-2.04) for pelvic malignancy. The SIR comparing RP patients with the general population was 1.11 (95% CI 0.98-1.25) for second malignancy and was 1.11 (95% CI 0.82-1.48) for pelvic malignancy. On multivariable analysis, older age (hazard ratio [HR] 1.05) and smoking (HR 1.65) were associated with increased second malignancy risk (P<.0001). Radical prostatectomy was not associated with a decreased second malignancy risk relative to BT (HR 0.90, P=.43), even when excluding patients who received postprostatectomy external beam radiation therapy (HR 1.13, P=.25). Older age (HR 1.09, P<.0001) and smoking (HR 2.17, P=.0009) were associated with increased pelvic malignancy risk. Radical prostatectomy was not associated with a decreased pelvic malignancy risk compared with BT (HR 0.57, P=.082), even when excluding postprostatectomy external beam radiation therapy patients (HR 0.87, P=.56). Conclusions: After adjustment for covariates, BT patients did not have an increased second

  2. Incidence of Second Malignancies in Prostate Cancer Patients Treated With Low-Dose-Rate Brachytherapy and Radical Prostatectomy

    International Nuclear Information System (INIS)

    Purpose: To compare the second malignancy incidence in prostate cancer patients treated with brachytherapy (BT) relative to radical prostatectomy (RP) and to compare both groups with the cancer incidence in the general population. Methods and Materials: From 1998 to 2010, 2418 patients were treated with Iodine 125 prostate BT monotherapy at the British Columbia Cancer Agency, and 4015 referred patients were treated with RP. Cancer incidence was compared with the age-matched general population using standardized incidence ratios (SIRs). Pelvic malignancies included invasive and noninvasive bladder cancer and rectal cancer. Cox multivariable analysis was performed with adjustment for covariates to determine whether treatment (RP vs BT) was associated with second malignancy risk. Results: The median age at BT was 66 years and at RP 62 years. The SIR comparing BT patients with the general population was 1.06 (95% confidence interval [CI] 0.91-1.22) for second malignancy and was 1.53 (95% CI 1.12-2.04) for pelvic malignancy. The SIR comparing RP patients with the general population was 1.11 (95% CI 0.98-1.25) for second malignancy and was 1.11 (95% CI 0.82-1.48) for pelvic malignancy. On multivariable analysis, older age (hazard ratio [HR] 1.05) and smoking (HR 1.65) were associated with increased second malignancy risk (P<.0001). Radical prostatectomy was not associated with a decreased second malignancy risk relative to BT (HR 0.90, P=.43), even when excluding patients who received postprostatectomy external beam radiation therapy (HR 1.13, P=.25). Older age (HR 1.09, P<.0001) and smoking (HR 2.17, P=.0009) were associated with increased pelvic malignancy risk. Radical prostatectomy was not associated with a decreased pelvic malignancy risk compared with BT (HR 0.57, P=.082), even when excluding postprostatectomy external beam radiation therapy patients (HR 0.87, P=.56). Conclusions: After adjustment for covariates, BT patients did not have an increased second

  3. Long-term observation of 64 patients with roentgenographically occult lung cancer treated with external irradiation and intraluminal irradiation using low-dose-rate iridium

    International Nuclear Information System (INIS)

    Therapeutic results of intraluminal irradiation were analyzed in 64 patients with roentgenographically occult lung cancer (ROLC). The subjects were 64 patients who underwent intraluminal irradiation between 1987 and 2003. Radiotherapy was performed by combining external irradiation with intraluminal irradiation using low-dose-rate iridium (four 370-MBq wires) through a catheter with a spacer. The doses of radiation were 0-70 Gy (median value 46 Gy) by external irradiation and 10-60 Gy (median value 29.3 Gy) by intraluminal irradiation. The therapeutic effect was complete response (CR) in 63 patients and partial response (PR) in 1 patient, and local recurrence was observed in a PR case and in seven of the 63 patients who showed CR. The 5-year overall and relapse-free survival rates were 56 (95% confidence interval (CI), 43-69%) and 55% (95% CI, 43-68%), respectively. Fatal pulmonary hemorrhage was observed in one case. Considering the facts that ROLC often occurs as multiple cancers and that many patients with ROLC have reduced lung function, radiation therapy by a combination of intraluminal and external irradiation may replace surgery as the first choice for the treatment of this disease. (author)

  4. External beam radiation therapy and a low-dose-rate brachytherapy boost without or with androgen deprivation therapy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Strom, Tobin J.; Hutchinson, Sean Z.; Shrinath, Kushagra; Cruz, Alex A.; Figura, Nicholas B.; Nethers, Kevin; Biagioli, Matthew C.; Fernandez, Daniel C.; Heysek, Randy V.; Wilder, Richard B., E-mail: richard.wilder@moffitt.org [Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL (United States)

    2014-07-15

    Purpose: To assess outcomes with external beam radiation therapy (EBRT) and a low-dose-rate (LDR) brachytherapy boost without or with androgen deprivation therapy (ADT) for prostate cancer. Materials and Methods: From January 2001 through August 2011, 120 intermediate-risk or high-risk prostate cancer patients were treated with EBRT to a total dose of 4,500 cGy in 25 daily fractions and a palladium-103 LDR brachytherapy boost of 10,000 cGy (n = 90) or an iodine-125 LDR brachytherapy boost of 11,000 cGy (n = 30). ADT, consisting of a gonadotropin-releasing hormone agonist ± an anti-androgen, was administered to 29/92 (32%) intermediate-risk patients for a median duration of 4 months and 26/28 (93%) high-risk patients for a median duration of 28 months. Results: Median follow-up was 5.2 years (range, 1.1-12.8 years). There was no statistically-significant difference in biochemical disease-free survival (bDFS), distant metastasis-free survival (DMFS), or overall survival (OS) without or with ADT. Also, there was no statistically-significant difference in bDFS, DMFS, or OS with a palladium-103 vs. an iodine-125 LDR brachytherapy boost. Conclusions: There was no statistically-significant difference in outcomes with the addition of ADT, though the power of the current study was limited. The Radiation Therapy Oncology Group 0815 and 0924 phase III trials, which have accrual targets of more than 1,500 men, will help to clarify the role ADT in locally-advanced prostate cancer patients treated with EBRT and a brachytherapy boost. Palladium-103 and iodine-125 provide similar bDFS, DMFS, and OS. (author)

  5. Prevalance rate of low-dose CT lung cancer screening. Results of a questionnaire survey of member facilities of Japan society of ningen dock with special concerns regarding the actual status and disincentives for implementing such screening

    International Nuclear Information System (INIS)

    We conducted a survey of member facilities of the Japan Society of Ningen Dock to elucidate the actual status of chest computed tomography (CT) screening and the reasons for not being able to change to low-dose CT. We sent a questionnaire consisting of 9 items to 531 member facilities in July 2010, response by facsimile to obtain an analysis. The prevalence rate of low-dose CT lung cancer screening slightly increased to 35% in comparison with the former survey done in November 2008. Some facilities indicated some shift in tube current to a lower range even though this was insufficient to meet the definition of low-dose CT. This reflects their thinking of ''Even with knowledge, there is strong hesitation to change to low-dose CT''. Among the reasons why they did not change to low-dose CT, a priority for high quality images was the top reason among problems of devices and performance. Informed consent was not yet adequate. It is necessary for manufactures to develop better technology to improve the image quality of low-dose CT and to report enough information to clinicians. On the medical side, perception of the necessity for appropriate reduction of radiation dose and the decision to move to low-dose CT would be of crucial significance for facility heads as well as radiologists and technicians. (author)

  6. Long-Term Efficacy and Toxicity of Low-Dose-Rate {sup 125}I Prostate Brachytherapy as Monotherapy in Low-, Intermediate-, and High-Risk Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kittel, Jeffrey A.; Reddy, Chandana A.; Smith, Kristin L.; Stephans, Kevin L.; Tendulkar, Rahul D. [Department of Radiation Oncology, Cleveland Clinic Taussig Cancer Institute, Cleveland, Ohio (United States); Ulchaker, James; Angermeier, Kenneth; Campbell, Steven; Stephenson, Andrew; Klein, Eric A. [Department of Urology, Cleveland Clinic Glickman Urological and Kidney Institute, Cleveland, Ohio (United States); Wilkinson, D. Allan [Department of Radiation Oncology, Cleveland Clinic Taussig Cancer Institute, Cleveland, Ohio (United States); Ciezki, Jay P., E-mail: ciezkij@ccf.org [Department of Radiation Oncology, Cleveland Clinic Taussig Cancer Institute, Cleveland, Ohio (United States)

    2015-07-15

    Purpose/Objectives: To report long-term efficacy and toxicity for a single-institution cohort of patients treated with low-dose-rate prostate brachytherapy permanent implant (PI) monotherapy. Methods and Materials: From 1996 to 2007, 1989 patients with low-risk (61.3%), intermediate-risk (29.8%), high-intermediate-risk (4.5%), and high-risk prostate cancer (4.4%) were treated with PI and followed up prospectively in a registry. All patients were treated with {sup 125}I monotherapy to 144 Gy. Late toxicity was coded retrospectively according to a modified Common Terminology Criteria for Adverse Events 4.0 scale. The rates of biochemical relapse-free survival (bRFS), distant metastasis-free survival (DMFS), overall survival (OS), and prostate cancer–specific mortality (PCSM) were calculated. We identified factors associated with late grade ≥3 genitourinary (GU) and gastrointestinal (GI) toxicity, bRFS, DMFS, OS, PCSM, and incontinence. Results: The median age of the patients was 67 years, and the median overall and prostate-specific antigen follow-up times were 6.8 years and 5.8 years, respectively. The overall 5-year rates for bRFS, DMFS, OS, and PCSM were 91.9%, 97.8%, 93.7%, and 0.71%, respectively. The 10-year rates were 81.5%, 91.5%, 76.1%, and 2.5%, respectively. The overall rates of late grade ≥3 GU and GI toxicity were 7.6% and 0.8%, respectively. On multivariable analysis, age and prostate length were significantly associated with increased risk of late grade ≥3 GU toxicity. The risk of incontinence was highly correlated with both pre-PI and post-PI transurethral resection of the prostate. Conclusions: Prostate brachytherapy as monotherapy is an effective treatment for low-risk and low-intermediate-risk prostate cancer and appears promising as a treatment for high-intermediate-risk and high-risk prostate cancer. Significant long-term toxicities are rare when brachytherapy is performed as monotherapy.

  7. Lung Cancer Screening with Low Dose CT

    Science.gov (United States)

    Caroline, Chiles

    2014-01-01

    SUMMARY The announcement of the results of the NLST, showing a 20% reduction in lung-cancer specific mortality with LDCT screening in a high risk population, marked a turning point in lung cancer screening. This was the first time that a randomized controlled trial had shown a mortality reduction with an imaging modality aimed at early detection of lung cancer. Current guidelines endorse LDCT screening for smokers and former smokers ages 55 to 74, with at least a 30 pack year smoking history. Adherence to published algorithms for nodule follow-up is strongly encouraged. Future directions for screening research include risk stratification for selection of the screening population, and improvements in the diagnostic follow-up for indeterminate pulmonary nodules. As with screening for other malignancies, screening for lung cancer with LDCT has revealed that there are indolent lung cancers which may not be fatal. More research is necessary if we are to maximize the risk-benefit ratio in lung cancer screening. PMID:24267709

  8. Lung cancer risk at low doses of alpha particles.

    Science.gov (United States)

    Hofmann, W; Katz, R; Zhang, C X

    1986-10-01

    A survey of inhabitant exposures arising from the inhalation of 222Rn and 220Rn progeny, and lung cancer mortality has been carried out in two adjacent areas in Guangdong Province, People's Republic of China, designated as the "high background" and the "control" area. Annual exposure rates are 0.38 working level months (WLM) per year in the high background, and 0.16 WLM/yr in the control area. In 14 yr of continuous study, from 1970 to 1983, age-adjusted mortality rates were found to be 2.7 per 10(5) living persons of all ages in the high background area, and 2.9 per 10(5) living persons in the control area. From this data, we conclude that we are unable to determine excess lung cancers over the normal fluctuations below a cumulative exposure of 15 WLM. This conclusion is supported by lung cancer mortality data from Austrian and Finnish high-background areas. A theoretical analysis of epidemiological data on human lung cancer incidence from inhaled 222Rn and 220Rn progeny, which takes into account cell killing as competitive with malignant transformation, leads to the evaluation of a risk factor which is either a linear-exponential or a quadratic-exponential function of the alpha-particle dose. Animal lung cancer data and theoretical considerations can be supplied to support either hypothesis. Thus we conclude that at our current stage of knowledge both the linear-exponential and the quadratic-exponential extrapolation to low doses seem to be equally acceptable for Rn-induced lung cancer risk, possibly suggesting a linear-quadratic transformation function with an exponential cell-killing term, or the influence of risk-modifying factors such as repair or proliferation stimuli.

  9. A database for a meta-analysis of cancer risk in animals at low doses and dose rates of ionising radiation

    International Nuclear Information System (INIS)

    Results of animal experiments listed in the International Radiobiology Archives (I.R.A.), complemented with data published in peer-reviewed literature since 1996 have been assembled in one data base and the induction of cancer at low doses has been analyzed. In total, approximately 100 separate, independent sets of experimental data have been studied. The main objective of this work is to provide information on radiation risk in the 0-500 mGy range. The data analyzed were those for which no significant reduction of life span was observed in exposed animals; or doses did not exceed 1 Gy; or no cancer was observed in exposed animals. With these criteria data sets with organ doses well in excess of 1 Gy were taken into account. In animals with a low natural incidence of cancer, the difference between the observed number of cancer cases and the prediction of the Linear No-threshold (LNT) hypothesis was compared in each experiment. Following intake of alpha emitters, the number of cancers observed is about 60% of the number of number predicted by the LNT, and only about 56% following intake of beta emitters. In some experiments, statistically weak protective effects were observed following the intake of alpha emitters, whereas apparently statistically strong protective effects were observed in some groups of animals exposed to beta radiation. In animals exposed to low LET radiation and neutrons, both clear excess cancer risk and clear cancer deficits were observed. In a second series of analysis, the several modeling approaches were used to model dose-response. Linear, logistic and probit regression models were examined. For all the data sets examined in this work, the analysis of the data using the LOGISTIC model seems to indicate surplus of negative slopes in the dose-response fits. Finer analyses are underway to determine what parameters are common to experiments which display similar dose-response relationships. If they exist in a sufficient number of experiments

  10. Implications of effects ''adaptive response'', ''low-dose hypersensitivity'' und ''bystander effect'' for cancer risk at low doses and low dose rates; Implikationen der Effekte ''adaptive response'', ''low-dose hypersensitivity'' und ''bystander effect'' fuer das Krebsrisiko bei niedrigen Dosen und Dosenraten

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, P (comp.)

    2006-07-01

    A model for carcinogenesis (the TSCE model) was applied in order to examine the effects of ''Low-dose hypersensitivity (LDH)'' and the ''Bystander effect (BE)'' on the derivation of radiation related cancer mortality risks. LDH has been discovered to occur in the inactivation of cells after acute exposure to low LET radiation. A corresponding version of the TSCE model was applied to the mortality data on the Abomb survivors from Hiroshima and Nagasaki. The BE has been mainly observed in cells after exposure to high LET radiation. A Version of the TSCE model which included the BE was applied to the data on lung cancer mortality from the workers at the Mayak nuclear facilities who were exposed to Plutonium. In general an equally good description of the A-bomb survivor mortality data (for all solid, stomach and lung tumours) was found for the TSCE model and the (conventional) empirical models but fewer parameters were necessary for the TSCE model. The TSCE model which included the effects of radiation induced cell killing resulted in non-linear dose response curves with excess relative risks after exposure at young ages that were generally lower than in the models without cell killing. The main results from TSCE models which included cell killing described by either conventional survival curves or LDH were very similar. A sub multiplicative effect from the interaction of smoking and exposure to plutonium was found to result from the analysis of the Mayak lung cancer mortality data. All models examined resulted in the predominant number of Mayak lung cancer deaths being ascribed to smoking. The interaction between smoking and plutonium exposures was found to be the second largest effect. The TSCE model resulted in lower estimates for the lung cancer excess relative risk per unit plutonium dose than the empirical risk model, but this difference was not found to be statistically significant. The excess relative risk dose responses

  11. Spectrum of early lung cancer presentation in low-dose screening CT: a pictorial review.

    Science.gov (United States)

    Rampinelli, Cristiano; Calloni, Sonia Francesca; Minotti, Marta; Bellomi, Massimo

    2016-06-01

    The typical presentation of early stage lung cancers on low-dose CT screening are non-calcified pulmonary nodules. However, there is a wide spectrum of unusual focal abnormalities that can be early presentations of lung cancer. These abnormalities include, for example, cancers associated with 'cystic airspaces' or scar-like cancers. The detection of lung cancer with low-dose CT can be affected by the absence of intravenous contrast medium. As a consequence, endobronchial and central lesions can be difficult to recognize, raising the potential for missed cancers. Focal lesions arising within pre-existing lung disease, such as lung fibrosis or apical scars, can also be early lung cancer manifestations and deserve particular consideration as recognition of these lesions may be hindered by the underlying disease. Furthermore, the unpredictable growth rate of lung cancer, which ranges from indolent to aggressive cancers, necessitates attention to the wide spectrum of progression in lung cancer appearance on serial low-dose CT scans. In this pictorial review we discuss the spectrum of early lung cancer presentation in low-dose CT screening, highlighting typical as well as unusual radiological features and the varied growth rates of early lung cancer. Teaching Points • There is a wide spectrum of early presentations of lung cancer on LDCT. • Low radiation dose and the absence of contrast medium injection can affect lung cancer detection. • Lung cancer growth shows various behaviours, ranging from indolent to aggressive cancers. • Familiarity with LDCT technique can improve CT screening effectiveness and avoid missed diagnosis. PMID:27188380

  12. The biological effect of 125I seed continuous low dose rate irradiation in CL187 cells

    Directory of Open Access Journals (Sweden)

    Zhuang Hong-Qing

    2009-01-01

    Full Text Available Abstract Background To investigate the effectiveness and mechanism of 125I seed continuous low-dose-rate irradiation on colonic cell line CL187 in vitro. Methods The CL187 cell line was exposed to radiation of 60Coγ ray at high dose rate of 2 Gy/min and 125I seed at low dose rate of 2.77 cGy/h. Radiation responses to different doses and dose rates were evaluated by colony-forming assay. Under 125I seed low dose rate irradiation, a total of 12 culture dishes were randomly divided into 4 groups: Control group, and 2, 5, and 10 Gy irradiation groups. At 48 h after irradiation, apoptosis was detected by Annexin and Propidium iodide (PI staining. Cell cycle arrests were detected by PI staining. In order to investigate the influence of low dose rate irradiation on the MAPK signal transduction, the expression changes of epidermal growth factor receptor (EGFR and Raf under continuous low dose rate irradiation (CLDR and/or EGFR monoclonal antibodies were determined by indirect immunofluorescence. Results The relative biological effect (RBE for 125I seeds compared with 60Co γ ray was 1.41. Apoptosis rates of CL187 cancer cells were 13.74% ± 1.63%, 32.58% ± 3.61%, and 46.27% ± 3.82% after 2 Gy, 5 Gy, and 10 Gy irradiation, respectively; however, the control group apoptosis rate was 1.67% ± 0.19%. G2/M cell cycle arrests of CL187 cancer cells were 42.59% ± 3.21%, 59.84% ± 4.96%, and 34.61% ± 2.79% after 2 Gy, 5 Gy, and 10 Gy irradiation, respectively; however, the control group apoptosis rate was 26.44% ± 2.53%. P 2/M cell cycle arrest. After low dose rate irradiation, EGFR and Raf expression increased, but when EGFR was blocked by a monoclonal antibody, EGFR and Raf expression did not change. Conclusion 125I seeds resulted in more effective inhibition than 60Co γ ray high dose rate irradiation in CL187 cells. Apoptosis following G2/M cell cycle arrest was the main mechanism of cell-killing effects under low dose rate irradiation. CLDR could

  13. Theory and data for estimating the risk at low doses and dose rates

    International Nuclear Information System (INIS)

    Radiological protection bases the Linear Non-Threshold (LNT) model for estimating the risk at low doses and dose rates. Incorporation of risk concept into radiological protection brought the LNT model that implies that there is no wholly ''safe'' dose of radiation. Epidemiological studies have provided statistically reasonable basis for the LNT model for radiological protection. In estimating the cancer risk at low dose and dose rate using the atomic bomb survivor data, the dose and dose rate effectiveness factor (DDREF) is estimated. Theoretical and methodological issues on the DDREF emerged from the biological points of view. The International Commission of Radiological Protection (ICRP) indicated that uncertainty analysis of the risk suggests that the LNT model is more reasonable than the threshold model with uncertain threshold doses. The latest epidemiological studies at low dose rates support LNT models. The gap between biology and epidemiology is increasing although some issues already exist in risk estimation at low doses. To get more scientifically reliable risk estimate, the dialogue between biology and epidemiology is needed to construct the framework of risk estimation such as biologically-based carcinogenesis models. (author)

  14. Use of alpha-1 adrenoceptor antagonists in patients who underwent low-dose-rate brachytherapy for prostate cancer - a randomized controlled trial of silodosin versus naftopidil -

    International Nuclear Information System (INIS)

    To evaluate the effect of two different alpha-1 adrenoceptor antagonists on lower urinary tract symptoms in patients who underwent LDR-brachytherapy. A total of 141 patients who had been clinically diagnosed with localized prostate cancer and underwent LDR-brachytherapy were enrolled. Patients were randomized and allocated to two groups (silodosin 8 mg vs. naftopidil 75 mg). The primary endpoint was a change in the international prostate symptom score (IPSS) at 3 months after seed implantation. Secondary endpoints included the recovery rate of IPSS at 12 months after seed implantation, the change in IPSS and overactive bladder symptom score, uroflowmetric parameters, and frequency volume chart (FVC). To determine independent variables that can predict IPSS recovery, logistic regression analysis was carried out. The mean change in the IPSS at 3 months after seed implantation in both groups was ⊿10.6 (naftopidil) and ⊿10.4 (silodosin), respectively. There was not a significant difference between the two groups (p=0.728). An increase in urinary frequency and a decrease in total urinated volume and mean voided volume were observed in FVC for 12 months after seed implantation. Multivariate analysis revealed that the urethral dose (UD30) was an independent predictive parameter of IPSS recovery. Patients with UD30 < 200Gy showed a higher recovery rate of IPSS at 12 months after seed implantation. There was no significant difference of serial change in IPSS between silodosin and naftopidil during the first year after seed implantation. A lower dose on the urethra was an independent predictor of IPSS recovery at 12 months after seed implantation

  15. Physics and quality assurance of low dose rate brachytherapy

    International Nuclear Information System (INIS)

    Purpose: The purpose of this course is to review the physical principles underlying design, clinical application and execution of interstitial and intracavitary implants in the classical low dose-rate (LDR) range. This year, the course will focus on quality assurance of sources, applicators and treatment planning software. In addition, development of procedures and QA checks designed optimize treatment delivery accuracy and patient safety during each individual procedure will be reviewed. The level of presentation will be designed to accommodate both physicists and physicians. Implementation of recently published AAPM Task Group reports (no. 40, 'Comprehensive Quality Assurance' and No. 43, 'Dosimetry of Interstitial Brachytherapy Sources') will be reviewed. Outline: (A) General Principles (1) QA endpoints: temporal accuracy, positional accuracy, dose delivery accuracy, and safety of the patient, personnel, and the institution (2) QA procedure development: forms, checklists, test development and design of treatment delivery procedures (B) QA of treatment delivery devices (1) Source acceptance testing and QA a) calibration and source strength specification standards b) leakage tests and source geometry verification (2) Applicator acceptance testing and QA (3) Remote afterloading devices (4) Treatment planning systems a) graphic input/output devices, implant geometry reconstruction, and graphical display b) dose calculation accuracy i) review of brachytherapy dose calculation algorithms ii) dosimetric benchmarks available: Task Group 43 report (C) Procedure-specific QA 1) Organization of treatment delivery team 2) Preplanning and preparation 3) Applicator insertion 4) Radiographic examination of the implant, prescription, and treatment calculation 5) Source insertion 6) Treatment planning and physicist review of treatment plans 7) QA during patient treatment and removal of sources and applicators

  16. Genetic Factors Affecting Susceptibility to Low Dose & Low Dose-Rate Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bedford, Joel

    2014-04-18

    Our laboratory has, among other things, developed and used the gamma H2AX focus assay and other chromosomal and cell killing assays to show that differences in this DNA double strand break (dsb) related response can be clearly and distinctly demonstrated for cells which are mildly hyper-radiosensitive such as those associated with A-T heterozygosity. We have found this level of mild hypersensitivity for cells from some 20 to 30 % of apparently normal individuals and from apparently normal parents of Retinoblastoma patients. We found significant differences in gene expression in somatic cells from unaffected parents of Rb patients as compared with normal controls, suggesting that these parents may harbor some as yet unidentified genetic abnormality. In other experiments we sought to determine the extent of differences in normal human cellular reaponses to radiation depending on their irradiation in 2D monolayer vs 3D organized acinar growth conditions. We exmined cell reproductive death, chromosomal aberration induction, and the levels of γ-H2AX foci in cells after single acute gamma-ray doses and immediately after 20 hours of irradiation at a dose rate of 0.0017 Gy/min. We found no significant differences in the dose-responses of these cells under the 2D or 3D growth conditions. While this does not mean such differences cannot occur in other situations, it does mean that they do not generally or necessarily occur. In another series of studies in collaboration with Dr Chuan Li, with supprt from this current grant. We reported a role for apoptotic cell death in promoting wound healing and tissue regeneration in mice. Apoptotic cells released growth signals that stimulated the proliferation of progenitor or stem cells. In yet another collaboration with Dr, B. Chen with funds from this grant, the relative radiosensitivity to cell killing as well as chromosomal instability of 13 DNA-PKcs site-directed mutant cell lines (defective at phosphorylation sites or kinase

  17. Cancer risk at low doses of ionizing radiation: artificial neural networks inference from atomic bomb survivors.

    Science.gov (United States)

    Sasaki, Masao S; Tachibana, Akira; Takeda, Shunichi

    2014-05-01

    Cancer risk at low doses of ionizing radiation remains poorly defined because of ambiguity in the quantitative link to doses below 0.2 Sv in atomic bomb survivors in Hiroshima and Nagasaki arising from limitations in the statistical power and information available on overall radiation dose. To deal with these difficulties, a novel nonparametric statistics based on the 'integrate-and-fire' algorithm of artificial neural networks was developed and tested in cancer databases established by the Radiation Effects Research Foundation. The analysis revealed unique features at low doses that could not be accounted for by nominal exposure dose, including (i) the presence of a threshold that varied with organ, gender and age at exposure, and (ii) a small but significant bumping increase in cancer risk at low doses in Nagasaki that probably reflects internal exposure to (239)Pu. The threshold was distinct from the canonical definition of zero effect in that it was manifested as negative excess relative risk, or suppression of background cancer rates. Such a unique tissue response at low doses of radiation exposure has been implicated in the context of the molecular basis of radiation-environment interplay in favor of recently emerging experimental evidence on DNA double-strand break repair pathway choice and its epigenetic memory by histone marking. PMID:24366315

  18. Simulated Microgravity and Low-Dose/Low-Dose-Rate Radiation Induces Oxidative Damage in the Mouse Brain.

    Science.gov (United States)

    Mao, Xiao Wen; Nishiyama, Nina C; Pecaut, Michael J; Campbell-Beachler, Mary; Gifford, Peter; Haynes, Kristine E; Becronis, Caroline; Gridley, Daila S

    2016-06-01

    Microgravity and radiation are stressors unique to the spaceflight environment that can have an impact on the central nervous system (CNS). These stressors could potentially lead to significant health risks to astronauts, both acutely during the course of a mission or chronically, leading to long-term, post-mission decrements in quality of life. The CNS is sensitive to oxidative injury due to high concentrations of oxidizable, unsaturated lipids and low levels of antioxidant defenses. The purpose of this study was to evaluate oxidative damage in the brain cortex and hippocampus in a ground-based model for spaceflight, which includes prolonged unloading and low-dose radiation. Whole-body low-dose/low-dose-rate (LDR) gamma radiation using (57)Co plates (0.04 Gy at 0.01 cGy/h) was delivered to 6 months old, mature, female C57BL/6 mice (n = 4-6/group) to simulate the radiation component. Anti-orthostatic tail suspension was used to model the unloading, fluid shift and physiological stress aspects of the microgravity component. Mice were hindlimb suspended and/or irradiated for 21 days. Brains were isolated 7 days or 9 months after irradiation and hindlimb unloading (HLU) for characterization of oxidative stress markers and microvessel changes. The level of 4-hydroxynonenal (4-HNE) protein, an oxidative specific marker for lipid peroxidation, was significantly elevated in the cortex and hippocampus after LDR + HLU compared to controls (P environment-induced oxidative stress. PMID:27243749

  19. Dosimetry Modeling for Focal Low-Dose-Rate Prostate Brachytherapy

    International Nuclear Information System (INIS)

    Purpose: Focal brachytherapy targeted to an individual lesion(s) within the prostate may reduce side effects experienced with whole-gland brachytherapy. The outcomes of a consensus meeting on focal prostate brachytherapy were used to investigate optimal dosimetry of focal low-dose-rate (LDR) prostate brachytherapy targeted using multiparametric magnetic resonance imaging (mp-MRI) and transperineal template prostate mapping (TPM) biopsy, including the effects of random and systematic seed displacements and interseed attenuation (ISA). Methods and Materials: Nine patients were selected according to clinical characteristics and concordance of TPM and mp-MRI. Retrospectively, 3 treatment plans were analyzed for each case: whole-gland (WG), hemi-gland (hemi), and ultra-focal (UF) plans, with 145-Gy prescription dose and identical dose constraints for each plan. Plan robustness to seed displacement and ISA were assessed using Monte Carlo simulations. Results: WG plans used a mean 28 needles and 81 seeds, hemi plans used 17 needles and 56 seeds, and UF plans used 12 needles and 25 seeds. Mean D90 (minimum dose received by 90% of the target) and V100 (percentage of the target that receives 100% dose) values were 181.3 Gy and 99.8% for the prostate in WG plans, 195.7 Gy and 97.8% for the hemi-prostate in hemi plans, and 218.3 Gy and 99.8% for the focal target in UF plans. Mean urethra D10 was 205.9 Gy, 191.4 Gy, and 92.4 Gy in WG, hemi, and UF plans, respectively. Mean rectum D2 cm3 was 107.5 Gy, 77.0 Gy, and 42.7 Gy in WG, hemi, and UF plans, respectively. Focal plans were more sensitive to seed displacement errors: random shifts with a standard deviation of 4 mm reduced mean target D90 by 14.0%, 20.5%, and 32.0% for WG, hemi, and UF plans, respectively. ISA has a similar impact on dose-volume histogram parameters for all plan types. Conclusions: Treatment planning for focal LDR brachytherapy is feasible. Dose constraints are easily met with a notable reduction

  20. Dosimetry Modeling for Focal Low-Dose-Rate Prostate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Al-Qaisieh, Bashar [Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Mason, Josh, E-mail: joshua.mason@nhs.net [Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Bownes, Peter; Henry, Ann [Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Dickinson, Louise [Division of Surgery and Interventional Science, University College London, London (United Kingdom); Department of Radiology, Northwick Park Hospital, London North West NHS Trust, London (United Kingdom); Ahmed, Hashim U. [Division of Surgery and Interventional Science, University College London, London (United Kingdom); University College London Hospital, London (United Kingdom); Emberton, Mark [University College London Hospital, London (United Kingdom); Langley, Stephen [St Luke' s Cancer Centre, Guildford (United Kingdom)

    2015-07-15

    Purpose: Focal brachytherapy targeted to an individual lesion(s) within the prostate may reduce side effects experienced with whole-gland brachytherapy. The outcomes of a consensus meeting on focal prostate brachytherapy were used to investigate optimal dosimetry of focal low-dose-rate (LDR) prostate brachytherapy targeted using multiparametric magnetic resonance imaging (mp-MRI) and transperineal template prostate mapping (TPM) biopsy, including the effects of random and systematic seed displacements and interseed attenuation (ISA). Methods and Materials: Nine patients were selected according to clinical characteristics and concordance of TPM and mp-MRI. Retrospectively, 3 treatment plans were analyzed for each case: whole-gland (WG), hemi-gland (hemi), and ultra-focal (UF) plans, with 145-Gy prescription dose and identical dose constraints for each plan. Plan robustness to seed displacement and ISA were assessed using Monte Carlo simulations. Results: WG plans used a mean 28 needles and 81 seeds, hemi plans used 17 needles and 56 seeds, and UF plans used 12 needles and 25 seeds. Mean D90 (minimum dose received by 90% of the target) and V100 (percentage of the target that receives 100% dose) values were 181.3 Gy and 99.8% for the prostate in WG plans, 195.7 Gy and 97.8% for the hemi-prostate in hemi plans, and 218.3 Gy and 99.8% for the focal target in UF plans. Mean urethra D10 was 205.9 Gy, 191.4 Gy, and 92.4 Gy in WG, hemi, and UF plans, respectively. Mean rectum D2 cm{sup 3} was 107.5 Gy, 77.0 Gy, and 42.7 Gy in WG, hemi, and UF plans, respectively. Focal plans were more sensitive to seed displacement errors: random shifts with a standard deviation of 4 mm reduced mean target D90 by 14.0%, 20.5%, and 32.0% for WG, hemi, and UF plans, respectively. ISA has a similar impact on dose-volume histogram parameters for all plan types. Conclusions: Treatment planning for focal LDR brachytherapy is feasible. Dose constraints are easily met with a notable

  1. Cancer and non-cancer risk at low doses of radiation: biological basis of radiation-environment interplay

    International Nuclear Information System (INIS)

    Cancer and non-cancer risk at low doses of ionizing radiation remains poorly defined due to ambiguity at low doses caused by limitations in statistical power and information available on interplay with environment. To deal with these problems, a novel non-parametric statistics was developed based on artificial neural networks theorem and applied to cancer and non-cancer risk in A-bomb survivors. The analysis revealed several unique features at low doses that could not be accounted for by nominal radiation dose alone. They include (1) threshold that varies with organ, gender and age, including cardiovascular diseases, (2) prevalence of infectious diseases, and (3) suppression of pathogenesis of HTLV1. The threshold is unique as it is manifested as negative excess relative risk, a reduction of spontaneous rate at low doses. The response is consistent with currently emerging laboratory data on DNA double-strand break (DSB) repair pathway choice and its sustainability as epigenetic memory in accordance with histone code theory. In response to DSB, of radiation or DNA replication arrest origin, distinct and competitively operating repair pathways are instigated. Activation by low doses of restitution-directed canonical non-homologous end-joining (C-NHEJ) suppresses both error-prone alternative end-joining (Alt-NHEJ) and homologous recombination (HR). The latter two present major pathways to mutagenesis at stalled replication folk associated with endogenous and exogenous genotoxin such as tobacco smoke metabolites and AID-associated somatic hypermutation and class switch recombination in Ig gene. Suppression of these error-prone pathways by low doses of low LET radiation is consistent with the reduction of cancer occurrence by environmental genotoxin, immunodiversity and stable integration of retrovirus DNA, providing a significant modulator of dose linearity at low doses. Whole picture may bring about a new landscape of cancer and non-cancer molecular epidemiology which

  2. A comparison of the biological effects of 125I seeds continuous low-dose-rate radiation and 60Co high-dose-rate gamma radiation on non-small cell lung cancer cells.

    Directory of Open Access Journals (Sweden)

    Zhongmin Wang

    Full Text Available To compare the biological effects of 125I seeds continuous low-dose-rate (CLDR radiation and 60Co γ-ray high-dose-rate (HDR radiation on non-small cell lung cancer (NSCLC cells.A549, H1299 and BEAS-2B cells were exposed to 125I seeds CLDR radiation or 60Co γ-ray HDR radiation. The survival fraction was determined using a colony-forming assay. The cell cycle progression and apoptosis were detected by flow cytometry (FCM. The expression of the apoptosis-related proteins caspase-3, cleaved-caspase-3, PARP, cleaved-PARP, BAX and Bcl-2 were detected by western blot assay.After irradiation with 125I seeds CLDR radiation, there was a lower survival fraction, more pronounced cell cycle arrest (G1 arrest and G2/M arrest in A549 and H1299 cells, respectively and a higher apoptotic ratio for A549 and H1299 cells than after 60Co γ-ray HDR radiation. Moreover, western blot assays revealed that 125I seeds CLDR radiation remarkably up-regulated the expression of Bax, cleaved-caspase-3 and cleaved-PARP proteins and down-regulated the expression of Bcl-2 proteins in A549 and H1299 cells compared with 60Co γ-ray HDR radiation. However, there was little change in the apoptotic ratio and expression of apoptosis-related proteins in normal BEAS-2B cells receiving the same treatment.125I seeds CLDR radiation led to remarkable growth inhibition of A549 and H1299 cells compared with 60Co HDR γ-ray radiation; A549 cells were the most sensitive to radiation, followed by H1299 cells. In contrast, normal BEAS-2B cells were relatively radio-resistant. The imbalance of the Bcl-2/Bax ratio and the activation of caspase-3 and PARP proteins might play a key role in the anti-proliferative effects induced by 125I seeds CLDR radiation, although other possibilities have not been excluded and will be investigated in future studies.

  3. Dosimetric Considerations to Determine the Optimal Technique for Localized Prostate Cancer Among External Photon, Proton, or Carbon-Ion Therapy and High-Dose-Rate or Low-Dose-Rate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Georg, Dietmar, E-mail: Dietmar.Georg@akhwien.at [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Hopfgartner, Johannes [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Gòra, Joanna [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Kuess, Peter [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Kragl, Gabriele [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Berger, Daniel [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Hegazy, Neamat [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Goldner, Gregor; Georg, Petra [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria)

    2014-03-01

    Purpose: To assess the dosimetric differences among volumetric modulated arc therapy (VMAT), scanned proton therapy (intensity-modulated proton therapy, IMPT), scanned carbon-ion therapy (intensity-modulated carbon-ion therapy, IMIT), and low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy (BT) treatment of localized prostate cancer. Methods and Materials: Ten patients were considered for this planning study. For external beam radiation therapy (EBRT), planning target volume was created by adding a margin of 5 mm (lateral/anterior–posterior) and 8 mm (superior–inferior) to the clinical target volume. Bladder wall (BW), rectal wall (RW), femoral heads, urethra, and pelvic tissue were considered as organs at risk. For VMAT and IMPT, 78 Gy(relative biological effectiveness, RBE)/2 Gy were prescribed. The IMIT was based on 66 Gy(RBE)/20 fractions. The clinical target volume planning aims for HDR-BT ({sup 192}Ir) and LDR-BT ({sup 125}I) were D{sub 90%} ≥34 Gy in 8.5 Gy per fraction and D{sub 90%} ≥145 Gy. Both physical and RBE-weighted dose distributions for protons and carbon-ions were converted to dose distributions based on 2-Gy(IsoE) fractions. From these dose distributions various dose and dose–volume parameters were extracted. Results: Rectal wall exposure 30-70 Gy(IsoE) was reduced for IMIT, LDR-BT, and HDR-BT when compared with VMAT and IMPT. The high-dose region of the BW dose–volume histogram above 50 Gy(IsoE) of IMPT resembled the VMAT shape, whereas all other techniques showed a significantly lower high-dose region. For all 3 EBRT techniques similar urethra D{sub mean} around 74 Gy(IsoE) were obtained. The LDR-BT results were approximately 30 Gy(IsoE) higher, HDR-BT 10 Gy(IsoE) lower. Normal tissue and femoral head sparing was best with BT. Conclusion: Despite the different EBRT prescription and fractionation schemes, the high-dose regions of BW and RW expressed in Gy(IsoE) were on the same order of magnitude. Brachytherapy techniques

  4. Chromosomal Aberrations in Normal and AT Cells Exposed to High Dose of Low Dose Rate Irradiation

    Science.gov (United States)

    Kawata, T.; Shigematsu, N.; Kawaguchi, O.; Liu, C.; Furusawa, Y.; Hirayama, R.; George, K.; Cucinotta, F.

    2011-01-01

    Ataxia telangiectasia (A-T) is a human autosomally recessive syndrome characterized by cerebellar ataxia, telangiectases, immune dysfunction, and genomic instability, and high rate of cancer incidence. A-T cell lines are abnormally sensitive to agents that induce DNA double strand breaks, including ionizing radiation. The diverse clinical features in individuals affected by A-T and the complex cellular phenotypes are all linked to the functional inactivation of a single gene (AT mutated). It is well known that cells deficient in ATM show increased yields of both simple and complex chromosomal aberrations after high-dose-rate irradiation, but, less is known on how cells respond to low-dose-rate irradiation. It has been shown that AT cells contain a large number of unrejoined breaks after both low-dose-rate irradiation and high-dose-rate irradiation, however sensitivity for chromosomal aberrations at low-dose-rate are less often studied. To study how AT cells respond to low-dose-rate irradiation, we exposed confluent normal and AT fibroblast cells to up to 3 Gy of gamma-irradiation at a dose rate of 0.5 Gy/day and analyzed chromosomal aberrations in G0 using fusion PCC (Premature Chromosomal Condensation) technique. Giemsa staining showed that 1 Gy induces around 0.36 unrejoined fragments per cell in normal cells and around 1.35 fragments in AT cells, whereas 3Gy induces around 0.65 fragments in normal cells and around 3.3 fragments in AT cells. This result indicates that AT cells can rejoin breaks less effectively in G0 phase of the cell cycle? compared to normal cells. We also analyzed chromosomal exchanges in normal and AT cells after exposure to 3 Gy of low-dose-rate rays using a combination of G0 PCC and FISH techniques. Misrejoining was detected in the AT cells only? When cells irradiated with 3 Gy were subcultured and G2 chromosomal aberrations were analyzed using calyculin-A induced PCC technique, the yield of unrejoined breaks decreased in both normal and AT

  5. Injury of the blood-testies barrier after low-dose-rate chronic radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Young Hoon; Bae Min Ji; Lee, Chang Geun; Yang, Kwang Mo; Jur, Kyu; Kim, Jong Sun [Dongnam Institute of Radiological and Medical Science, Busan (Korea, Republic of)

    2014-04-15

    The systemic effect of radiation increases in proportionally with the dose and dose rate. Little is known concerning the relationships between harmful effects and accumulated dose, which is derived from continuous low-dose rate radiation exposure. Recent our studies show that low-dose-rate chronic radiation exposure (3.49 mGy/h) causes adverse effects in the testis at a dose of 2 Gy (6 mGy/h). However, the mechanism of the low-dose-rate 2 Gy irradiation induced testicular injury remains unclear. The present results indicate that low-dose rate chronic radiation might affect the BTB permeability, possibly by decreasing levels of ZO-1, Occludin-1, and NPC-2. Furthermore, our results suggest that there is a risk of male infertility through BTB impairment even with low-dose-rate radiation if exposure is continuous.

  6. Modeling low-dose-rate effects in irradiated bipolar-base oxides

    Energy Technology Data Exchange (ETDEWEB)

    Graves, R.J.; Cirba, C.R.; Schrimpf, R.D.; Milanowski, R.J.; Saigne, F. [Vanderbilt Univ., Nashville, TN (United States); Michez, A. [Univ. Montpellier 2 (France); Fleetwood, D.M. [Sandia National Labs., Albuquerque, NM (United States); Witczak, S.C. [Aerospace Corp., Los Angeles, CA (United States)

    1997-02-01

    A physical model is developed to quantify the contribution of oxide-trapped charge to enhanced low-dose-rate gain degradation in BJTs. Simulations show that space charge limited transport is partially responsible for the low-dose-rate enhancement.

  7. Low dose intravesical heparin as prophylaxis against recurrent noninvasive (stage Ta) bladder cancer

    DEFF Research Database (Denmark)

    Bitsch, M; Hermann, G G; Andersen, J P;

    1990-01-01

    A controlled randomized clinical trial was conducted to examine the efficacy of topical low dose heparin (0.125 gm./l., 25,000 units per l.) as prophylaxis against recurrent noninvasive (stage Ta) transitional cell bladder cancer. Transurethral tumor resection was done with irrigation fluid...... containing either 1.5% glycine with heparin or glycine solution alone. Tumor recurrence was determined by cystoscopy 4 to 6 months later. There were 70 patients evaluated: 38 in the heparin and 32 in the control group, respectively. The recurrence rate (heparin 74%, control 66%) and the median number...... of recurrences (heparin 3, range 1 to 15 and control 3, range 1 to 30) were similar (p greater than 0.05) in the 2 groups of patients. These observations show that low dose heparin administered in the irrigation fluid during transurethral resection does not decrease the recurrence rate of noninvasive (stage Ta...

  8. Early detection of lung cancer using low-dose CT: an update; Lungenkrebsfrueherkennung mit Low-dose-CT: ein Update

    Energy Technology Data Exchange (ETDEWEB)

    Diederich, S.; Wormanns, D.; Heindel, W. [Institut fuer Klinische Radiologie, Universitaetsklinikum Muenster (Germany)

    2002-08-01

    Lung cancer is the leading cause of death from malignancy. Due to a lack of early symptoms patients usually undergo therapy at advanced tumor stages when prognosis is poor. Feasibility studies of low-dose spiral CT screening of heavy smokers have shown that many small, resectable lung cancers can be diagnosed at early stages using simple diagnostic algorithms based on size and attenuation of detected pulmonary nodules with a small proportion of invasive procedures for benign lesions. Preliminary results of repeat screening confirms small size and favourable stage distribution of detected cancers, using even simpler diagnostic algorithms: additional diagnostic procedures are only required in new or growing nodules whereas follow-up with low-dose CT is sufficient in nodules that appear unchanged to exclude slow growth. However, mortality reduction by lung cancer screening with low-dose CT has yet to be demonstrated. Several randomised controlled trials are under way to assess possible mortality reduction by comparison of mortalities in a screening group and a control group. It is hoped that through international cooperation data from these trials can be pooled to allow for statistically significant conclusions as early as possible. (orig.) [German] Lungenkrebs ist die haeufigste zum Tode fuehrende maligne Erkrankung. Wegen des Fehlens von Fruehsymptomen kommen Patienten meist in fortgeschrittenen Tumorstadien zur Behandlung, wenn die Prognose sehr schlecht ist. Machbarkeitsstudien zum Einsatz der Niedrigdosis-Spiral-Computertomographie bei starken Rauchern haben gezeigt, dass sich bei Einsatz simpler, auf Groesse und Dichte gefundener Rundherde basierender diagnostischer Algorithmen eine grosse Zahl kleiner, resektabler Bronchialkarzinome in fruehen Stadien diagnostizieren liess, wobei der Anteil invasiver Massnahmen wegen benigner Laesionen gering war. Erste Ergebnisse von Wiederholungsuntersuchungen zeigen wiederum eine geringe Groesse und guenstige

  9. Modeling Low-Dose-Rate Effects in Irradiated Bipolar-Base Oxides

    Energy Technology Data Exchange (ETDEWEB)

    Cirba, C.R.; Fleetwood, D.M.; Graves, R.J.; Michez, A.; Milanowski, R.J.; Saigne, F.; Schrimpf, R.D.; Witczak, S.C.

    1998-10-26

    A physical model is developed to quantify the contribution of oxide-trapped charge to enhanced low-dose-rate gain degradation in bipolar junction transistors. Multiple-trapping simulations show that space charge limited transport is partially responsible for low-dose-rate enhancement. At low dose rates, more holes are trapped near the silicon-oxide interface than at high dose rates, resulting in larger midgap voltage shifts at lower dose rates. The additional trapped charge near the interface may cause an exponential increase in excess base current, and a resultant decrease in current gain for some NPN bipolar technologies.

  10. Low doses effects and gamma radiations low dose rates; Les effets des faibles doses et des faibles debits de doses de rayons gamma

    Energy Technology Data Exchange (ETDEWEB)

    Averbeck, D. [Institut Curie, CNRS UMR 2027, 75 - Paris (France)

    1999-07-01

    This expose wishes for bringing some definitions and base facts relative to the problematics of low doses effects and low dose rates effects. It shows some already used methods and some actual experimental approaches by focusing on the effects of ionizing radiations with a low linear energy transfer. (N.C.)

  11. Enhanced charge trapping in bipolar spacer oxides during low-dose-rate irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Fleetwood, D.M.; Reber, R.A. Jr.; Winokur, P.S. [Sandia National Labs., Albuquerque, NM (United States); Kosier, S.L.; Schrimpf, R.D. [Arizona Univ., Tucson, AZ (United States). Dept. of Electrical and Computer Engineering; Nowlin, R.N. [Air Force Phillips Laboratory, Albuquerque, NM (United States); Pease, R.L. [RLP Research, Inc., Albuquerque, NM (United States); DeLaus, M. [Analog Devices, Wilmington, MA (United States)

    1994-03-01

    Thermally-stimulated-current and capacitance-voltage measurements reveal enhanced hole trapping in bipolar spacer-oxide capacitors irradiated at 0 V at low dose rates. Possible mechanisms and implications for bipolar low-rate response are discussed.

  12. Cohort studies on cancer mortality among nuclear workers exposed to low-dose ionizing radiation: a meta-analysis

    International Nuclear Information System (INIS)

    To provide direct estimates of risk of cancer after protracted low doses of ionising radiation and to strengthen the scientific basis of radiation protection standards for low-dose ionising radiation exposure. Published papers referring to 20 low-dose ionising radiation-exposed cohorts among nuclear industry workers with Standardized Mortality Ratios (SMR) were recta-analyzed in fixed and random effect models. The significantly deficient Meta-SMRs for all deaths (0.73; 95% CI: 0.66-0.80), all cancers (0.83; 95% CI: 0.77- 0.91), lung cancer (0.93; 95% CI: 0.90-0.95), non-Hodgkin lymphoma (0.88; 95% CI: 0.78- 0.99), esophagus cancer (0.83; 95% CI:0.76-0.91), colorectal cancer (0.88; 95% CI: 0.83-0.94), stomach cancer (0.81; 95% CI: 0.76-0.86) were observed. The Meta-SMRs for leukemia, multiple myeloma, Hodgkin's disease were found to be no significant difference with normal populations. There was no excessive risk of cancers among nuclear workers exposed to low-doses and low-dose rates ionizing radiation. (authors)

  13. Evaluation of Enhanced Low Dose Rate Sensitivity in Discrete Bipolar Junction Transistors

    Science.gov (United States)

    Chen, Dakai; Ladbury Raymond; LaBel, Kenneth; Topper, Alyson; Ladbury, Raymond; Triggs, Brian; Kazmakites, Tony

    2012-01-01

    We evaluate the low dose rate sensitivity in several families of discrete bipolar transistors across device parameter, quality assurance level, and irradiation bias configuration. The 2N2222 showed the most significant low dose rate sensitivity, with low dose rate enhancement factor of 3.91 after 100 krad(Si). The 2N2907 also showed critical degradation levels. The devices irradiated at 10 mrad(Si)/s exceeded specifications after 40 and 50 krad(Si) for the 2N2222 and 2N2907 devices, respectively.

  14. Health Risks From Low Doses and Low Dose-Rates of Ionizing Radiation. Session 5: Future of Radiation Protection Regulations.

    Science.gov (United States)

    Cool, Donald A

    2016-03-01

    The system of radiological protection is a prospective approach to protection of individuals in all exposure situations. It must be applied equitably across all age groups and all populations. This is a very different circumstance from dose assessment for a particular individual where the unique characteristics of the individual and the exposure can be taken into account. Notwithstanding the ongoing discussions on the possible shape of the dose response at low doses and dose rates, the prospective system of protection has therefore historically used a linear assumption as a pragmatic, prudent and protective approach. These radiation protection criteria are not intended to be a demarcation between "safe" and "unsafe" and are the product of a risk-informed judgement that includes inputs from science, ethics, and experience. There are significant implications for different dose response relationships. A linear model allows for equal treatment of an exposure, irrespective of the previously accumulated exposure. In contrast, other models would predict different implications. Great care is therefore needed in separating the thinking around risk assessment from risk management, and prospective protection for all age groups and genders from retrospective assessment for a particular individual. In the United States, the prospective regulatory structure functions effectively because of assumptions that facilitate independent treatment of different types of exposures, and which provide pragmatic and prudent protection. While the a linear assumption may, in fact, not be consistent with the biological reality, the implications of a different regulatory model must be considered carefully. PMID:26808877

  15. Low Dose Radiation Cancer Risks: Epidemiological and Toxicological Models

    Energy Technology Data Exchange (ETDEWEB)

    David G. Hoel, PhD

    2012-04-19

    The basic purpose of this one year research grant was to extend the two stage clonal expansion model (TSCE) of carcinogenesis to exposures other than the usual single acute exposure. The two-stage clonal expansion model of carcinogenesis incorporates the biological process of carcinogenesis, which involves two mutations and the clonal proliferation of the intermediate cells, in a stochastic, mathematical way. The current TSCE model serves a general purpose of acute exposure models but requires numerical computation of both the survival and hazard functions. The primary objective of this research project was to develop the analytical expressions for the survival function and the hazard function of the occurrence of the first cancer cell for acute, continuous and multiple exposure cases within the framework of the piece-wise constant parameter two-stage clonal expansion model of carcinogenesis. For acute exposure and multiple exposures of acute series, it is either only allowed to have the first mutation rate vary with the dose, or to have all the parameters be dose dependent; for multiple exposures of continuous exposures, all the parameters are allowed to vary with the dose. With these analytical functions, it becomes easy to evaluate the risks of cancer and allows one to deal with the various exposure patterns in cancer risk assessment. A second objective was to apply the TSCE model with varing continuous exposures from the cancer studies of inhaled plutonium in beagle dogs. Using step functions to estimate the retention functions of the pulmonary exposure of plutonium the multiple exposure versions of the TSCE model was to be used to estimate the beagle dog lung cancer risks. The mathematical equations of the multiple exposure versions of the TSCE model were developed. A draft manuscript which is attached provides the results of this mathematical work. The application work using the beagle dog data from plutonium exposure has not been completed due to the fact

  16. Health effects of low doses at low dose rates: dose-response relationship modeling in a cohort of workers of the nuclear industry

    International Nuclear Information System (INIS)

    The aim of this thesis is to contribute to a better understanding of the health effects of chronic external low doses of ionising radiation. This work is based on the French cohort of CEA-AREVA NC nuclear workers. The mains stages of this thesis were (1) conducting a review of epidemiological studies on nuclear workers, (2) completing the database and performing a descriptive analysis of the cohort, (3) quantifying risk by different statistical methods and (4) modelling the exposure-time-risk relationship. The cohort includes monitored workers employed more than one year between 1950 and 1994 at CEA or AREVA NC companies. Individual annual external exposure, history of work, vital status and causes of death were reconstructed for each worker. Standardized mortality ratios using French national mortality rates as external reference were computed. Exposure-risk analysis was conducted in the cohort using the linear excess relative risk model, based on both Poisson regression and Cox model. Time dependent modifying factors were investigated by adding an interaction term in the model or by using exposure time windows. The cohort includes 36, 769 workers, followed-up until age 60 in average. During the 1968- 2004 period, 5, 443 deaths, 2, 213 cancers, 62 leukemia and 1, 314 cardiovascular diseases were recorded. Among the 57% exposed workers, the mean cumulative dose was 21.5 milli-sieverts (mSv). A strong Healthy Worker Effect is observed in the cohort. Significant elevated risks of pleura cancer and melanoma deaths were observed in the cohort but not associated with dose. No significant association was observed with solid cancers, lung cancer and cardiovascular diseases. A significant dose-response relationship was observed for leukemia excluding chronic lymphatic leukemia, mainly for doses received less than 15 years before and for yearly dose rates higher than 10 mSv. This PhD work contributes to the evaluation of risks associated to chronic external radiation

  17. Coronary artery calcification scoring in low-dose ungated CT screening for lung cancer: interscan agreement.

    NARCIS (Netherlands)

    Jacobs, P.C.; Isgum, I.; Gondrie, M.J.; Mali, W.P.Th.; Ginneken, B. van; Prokop, M.; Graaf, Y. van der

    2010-01-01

    OBJECTIVE: In previous studies detection of coronary artery calcification (CAC) with low-dose ungated MDCT performed for lung cancer screening has been compared with detection with cardiac CT. We evaluated the interscan agreement of CAC scores from two consecutive low-dose ungated MDCT examinations.

  18. Coronary Artery Calcification Scoring in Low-Dose Ungated CT Screening for Lung Cancer : Interscan Agreement

    NARCIS (Netherlands)

    Jacobs, Peter C. A.; Isgum, Ivana; Gondrie, Martijn J. A.; Mali, Willem P. Th. M.; van Ginneken, Bram; Prokop, Mathias; van der Graaf, Yolanda

    2010-01-01

    OBJECTIVE. In previous studies detection of coronary artery calcification (CAC) with low-dose ungated MDCT performed for lung cancer screening has been compared with detection with cardiac CT. We evaluated the interscan agreement of CAC scores from two consecutive low-dose ungated MDCT examinations.

  19. Effect of low-dose X-ray radiation on adaptive response in gastric cancer cell

    Institute of Scientific and Technical Information of China (English)

    Shukai Wang; Gang Jiang; Hongsheng Yu; Xiangping Liu; Chang Xu

    2013-01-01

    Objective: We aimed to study the effect and mechanism of low-dose radiation (LDR) on adaptive response of gastric cancer cell. Methods: SGC7901 cells were cultured in vitro, and divided into 4 groups: control group (D0 group), low-dose radiation group (D1 group, 75 mGy), high-dose radiation group (D2 group, 2 Gy), low-dose plus high-dose radiation group (D1 + D2 group, 75 mGy + 2 Gy, the interval of low and high-dose radiation being 8 h). Cell inhibition rate was detected by cytometry and CCK8 method; the proportion of cell cycle at different times after irradiation was determined by using a flow cytometry. The ATM mRNA levels were detected by using quantitative real-time reverse transcription polymerase chain reaction (RT-PCR). Results: There was no significant different between groups D0 and D1, groups D2 and D1 + D2 cell inhibition rate (P > 0.05). There was a significant increase G2/M arrest in groups D2 and D1 + D2 than groups D0 and D1 after 6 h of radiation and did not recover at 48 h (P 0.05). Conclusion: LDR cannot induce adaptive response in SGC7901 cells in vitro, which may be associated the regulation of cell cycle, and its ATM mRNA expression cannot be affected by 75 mGy X-ray radiation.

  20. Mortality from diseases other than cancer following low doses of ionizing radiation

    DEFF Research Database (Denmark)

    Vrijheid, M; Cardis, E; Ashmore, P;

    2007-01-01

    BACKGROUND: Ionizing radiation at very high (radio-therapeutic) dose levels can cause diseases other than cancer, particularly heart diseases. There is increasing evidence that doses of the order of a few sievert (Sv) may also increase the risk of non-cancer diseases. It is not known, however......, whether such effects also occur following the lower doses and dose rates of public health concern. METHODS: We used data from an international (15-country) nuclear workers cohort study to evaluate whether mortality from diseases other than cancer is related to low doses of external ionizing radiation....... Analyses included 275 312 workers with adequate information on socioeconomic status, over 4 million person-years of follow-up and an average cumulative radiation dose of 20.7 mSv; 11 255 workers had died of non-cancer diseases. RESULTS: The excess relative risk (ERR) per Sv was 0.24 [95% CI (confidence...

  1. Low-dose CT scan screening for lung cancer: comparison of images and radiation doses between low-dose CT and follow-up standard diagnostic CT

    OpenAIRE

    ONO, KOJI; Hiraoka, Toru; Ono, Asami; Komatsu, Eiji; Shigenaga, Takehiko; Takaki, Hajime; Maeda, Toru; Ogusu, Hiroyuki; Yoshida, Shintaro; Fukushima, Kiyoyasu; Kai, Michiaki

    2013-01-01

    Objectives This study aim to compare image quality and radiation doses between low-dose CT and follow-up standard diagnostic CT for lung cancer screening. Methods In a single medical institution, 19 subjects who had been screened for lung cancer by low-dose CT before going through follow-up standard diagnostic CT were randomly selected. Both CT image sets for all subjects were independently evaluated by five specialized physicians. Results There were no significant differences between low-dos...

  2. Thermal-stress effects on enhanced low-dose-rate sensitivity of linear bipolar circuits

    Energy Technology Data Exchange (ETDEWEB)

    SHANEYFELT,MARTY R.; SCHWANK,JAMES R.; WITCZAK,STEVEN C.; RIEWE,LEONARD CHARLES; WINOKUR,PETER S.; HASH,GERALD L.; PEASE,R.L.; FLEETWOOD,D.M.

    2000-02-17

    Thermal-stress effects are shown to have a significant impact on the enhanced low-dose-rate sensitivity of linear bipolar circuits. Implications of these results on hardness assurance testing and mechanisms are discussed.

  3. Impact of post-implant dosimetric parameters on the quality of life of patients treated with low-dose rate brachytherapy for localised prostate cancer: results of a single-institution study

    International Nuclear Information System (INIS)

    To assess the relationship between dosimetric parameters and the quality of life (QL) outcomes of patients with low-intermediate-risk localised prostate cancer (LPC) treated with low-dose-rate brachytherapy (LDR-BT). We evaluated the participants in two consecutive prospective studies of the QL of patients treated with LDR-BT for LPC. QL was evaluated by means of a patient-completed questionnaire assessing non functional [physical (PHY) and psychological (PSY) well-being, physical autonomy (POW), social relationships (REL)] and functional scales [urinary (URI), rectal (REC), and sexual (SEX) function]; a scale for erectile function (ERE) was included in the second study. Urethra (D10 ≤ 210 Gy) and rectal wall constraints (V100 ≤ 0.5 cc) were used for pre-planning dosimetry and were assessed with post planning computerized tomography one month later for each patient. QL was assessed in 251 LPC patients. Dosimetry did not influence the non-functional scales. As expected, a progressive impairment in sexual and erectile function was reported one month after LDR-BT, and became statistically significant after the third year. Rectal function significantly worsened after LDR-BT, but the differences progressively decreased after the 1-year assessment. Overall urinary function significantly worsened immediately after LDR-BT and then gradually improved over the next three years. Better outcomes were reported for V100 rectal wall volumes of ≤ 0.5 cc and D10 urethra values of ≤ 210 Gy. The findings of this study show that dosimetric parameters influence only functional QL outcomes while non-functional outcomes are only marginally influenced

  4. 20 percent lower lung cancer mortality with low-dose CT vs chest X-ray

    Science.gov (United States)

    Scientists have found a 20 percent reduction in deaths from lung cancer among current or former heavy smokers who were screened with low-dose helical computed tomography (CT) versus those screened by chest X-ray.

  5. Lung cancer screening by low-dose spiral computed tomography

    NARCIS (Netherlands)

    van Klaveren, RJ; Habbema, JDF; Pedersen, JH; de Koning, HJ; Oudkerk, M; Hoogsteden, HC

    2001-01-01

    The poor prognosis of lung cancer has barely changed in the last decades, but the prognosis is better when the disease is detected earlier. Lung cancer screening by chest radiography did not lead to a decrease in lung cancer mortality, presumably because the chest radiograph is a poor screening tool

  6. Low-dose-rate brachytherapy as the sole radiation modality in the management of patients with early-stage breast cancer treated with breast-conserving therapy: preliminary results of a pilot trial

    International Nuclear Information System (INIS)

    Purpose: We present the preliminary findings of our in-house protocol treating the tumor bed alone after lumpectomy with low-dose-rate (LDR) interstitial brachytherapy in selected patients with early-stage breast cancer treated with breast-conserving therapy (BCT). Methods and Materials: Since March 1, 1993, 60 women with early-stage breast cancer were entered into a protocol of tumor bed irradiation only using an interstitial LDR implant with iodine-125. Patients were eligible if the tumor was ≤3 cm, margins were ≥2 mm, there was no extensive intraductal component, the axilla was surgically staged, and a postoperative mammogram was performed. Implants were placed using a standardized template either at the time of reexcision or shortly after lumpectomy. A total of 50 Gy was delivered at 0.52 Gy/h over a period of 96 h to the lumpectomy bed plus a 2-cm margin. Perioperative complications, cosmetic outcome, and local control were assessed. Results: The median follow-up for all patients is 20 months. Three patients experienced minimal perioperative pain that required temporary nonnarcotic analgesics. There have been four postoperative infections which resolved with oral antibiotics. No significant skin reactions related to the implant were noted and no patient experienced impaired would healing. Early cosmetic results reveal minimal changes consisting of transient hyperpigmentation of the skin at the puncture sites and temporary induration in the tumor bed. Good to excellent cosmetic results were noted in all 19 patients followed up a minimum of 24 months posttherapy. To date, 51 women have obtained 6-12-month follow-up mammograms and no recurrences have been noted. All patients currently have no physical signs of recurrence, and no patient has failed regionally or distantly. Conclusion: Treatment of the tumor bed alone with LDR interstitial brachytherapy appears to be well tolerated, and early results are promising. Long-term follow-up of these patients is

  7. Low-dose capecitabine (Xeloda) for treatment for gastrointestinal cancer

    OpenAIRE

    Miger, Jasmine; Holmqvist, Annica; Sun, Xiao-Feng; Albertsson, Maria

    2014-01-01

    The prodrug capecitabine (Xeloda) has been an important drug for treatment for gastrointestinal cancer (GI-cancer). This study explores the efficacy of continuous metronomic Xeloda, as well as tolerability and best response during treatment. Patients (n = 35) with stage IV GI-cancer were included in the study and were divided into two groups; upper (n = 13) and lower (n = 22) GI-cancer. All patients were given continuous metronomic Xeloda (500 mg × 2). Best response was measured by radiologic...

  8. Risk of Low Dose/Low Dose Rate Ionizing Radiation to Humans Symposium at the EMS 2009 Annual Meeting - September 2006

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, William F.; von Borstel, Robert C.; Brenner,; Redpath, J. Leslie; Erickson, Barbra E.; Brooks,

    2009-11-12

    The low dose symposium thoughtfully addressed controversy of risk from low dose radiation exposure, hormesis and radon therapy. The stem cell symposium cogently considered the role of DNA damage and repair in hematopoietic stem cells underlying aging and malignancy and provocatively presented evidence that stem cells may have distinct morphologies and replicative properties, as well as special roles in cancer initiation. In the epigenetics symposium, studies illustrated the long range interaction of epigenetic mechanisms, the roles of CTCF and BORIS in region/specific regulation of epigenetic processes, the impact of DNA damage on epigenetic processes as well as links between epigenetic mechanisms and early nutrition and bystander effects.

  9. Review of low dose-rate epidemiological studies and biological mechanisms of dose-rate effects on radiation induced carcinogenesis

    International Nuclear Information System (INIS)

    Radiation protection system adopts the linear non-threshold model with using dose and dose-rate effectiveness factor (DDREF). The dose-rate range where DDREF is applied is below 100 mGy per hour, and it is regarded that there are no dose-rate effects at very low dose rate, less than of the order of 10 mGy per year, even from the biological risk evaluation model based on cellular and molecular level mechanisms for maintenance of genetic integrity. Among low dose-rate epidemiological studies, studies of residents in high natural background areas showed no increase of cancer risks at less than about 10 mGy per year. On the other hand, some studies include a study of the Techa River cohort suggested the increase of cancer risks to the similar degree of Atomic bomb survivor data. The difference of those results was supposed due to the difference of dose rate. In 2014, International Commission on Radiological Protection opened a draft report on stem cell biology for public consultations. The report proposed a hypothesis based on the new idea of stem cell competition as a tissue level quality control mechanism, and suggested that it could explain the dose-rate effects around a few milligray per year. To verify this hypothesis, it would be needed to clarify the existence and the lowest dose of radiation-induced stem cell competition, and to elucidate the rate of stem cell turnover and radiation effects on it. As for the turnover, replenishment of damaged stem cells would be the important biological process. It would be meaningful to collect the information to show the difference of dose rates where the competition and the replenishment would be the predominant processes. (author)

  10. Low-dose paclitaxel modulates tumour fibrosis in gastric cancer

    OpenAIRE

    TSUKADA, TOMOYA; Fushida, Sachio; Harada, Shinichi; Terai, Shiroh; Yagi, Yasumichi; Kinoshita, Jun; OYAMA, KATSUNOBU; Tajima, Hidehiro; NINOMIYA, ITASU; FUJIMURA, TAKASHI; Ohta, Tetsuo

    2013-01-01

    Various treatments have been used for peritoneal dissemination, which is the most common mode of metastasis in gastric cancer, but sufficiently good clinical outcomes have not yet been obtained because of the presence of rich fibrous components and acquired drug resistance. Epithelialmesenchymal transition (EMT) is one of the major causes of tissue fibrosis and transforming growth factor-β (TGF-β) has a pivotal function in the progression of EMT. Smad proteins play an important role in the TG...

  11. Risk of breast cancer following low-dose radiation exposure

    International Nuclear Information System (INIS)

    Risk of breast cancer following radiation exposure was studied, based on surveys of tuberculosis patients who had multiple fluoroscopic examinations of the chest, mastitis patients given radiotherapy, and atomic bomb survivors. Analysis suggests that the risk is greatest for persons exposed as adolescents, although exposure at all ages carries some risk. The dose-response relationship was consistent with linearity in all studies. Direct evidence of radiation risk at doses under 0.5 Gy (50 rad) is apparent among A-bomb survivors. Fractionation does not appear to diminish risk, nor does time since exposure (even after 45 years of observation). The interval between exposure and the clinical appearance of radiogenic breast cancer may be mediated by hormonal or other age-related factors but is unrelated to dose. Age-specific absolute risk estimtes for all studies are remarkably similar. The best estimate of risk among American women exposed after age 20 is 6.6 excess cancers/104 WY-Gy

  12. Low-dose aspirin or other nonsteroidal anti-inflammatory drug use and prostate cancer risk

    DEFF Research Database (Denmark)

    Skriver, Charlotte; Dehlendorff, Christian; Borre, Michael;

    2016-01-01

    PURPOSE: Increasing evidence suggests that aspirin use may protect against prostate cancer. In a nationwide case-control study, using Danish high-quality registry data, we evaluated the association between the use of low-dose aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs......) and the risk of prostate cancer. METHODS: We identified 35,600 patients (cases) with histologically verified prostate cancer during 2000-2012. Cases were matched to 177,992 population controls on age and residence by risk-set sampling. Aspirin and nonaspirin NSAID exposure was defined by type, estimated dose......, duration, and consistency of use. We used conditional logistic regression to estimate odds ratios (ORs), with 95 % confidence intervals (CIs), for prostate cancer associated with low-dose aspirin (75-150 mg) or nonaspirin NSAID use, adjusted for potential confounders. RESULTS: Use of low-dose aspirin...

  13. Calculations of cell survival at low dose rates using the LPL model

    International Nuclear Information System (INIS)

    The lethal potentially lethal (LPL) model is used to study the low dose rate problem. During irradiation, it is assumed that lesions are being created, repaired, and misrepaired. Two differential equations are used to describe the variations of the rates of production with time of potentially lethal (n/sub B/) and lethal (n/sub C/) lesions, respectively

  14. Cancer risk from low doses of ionizing radiation

    International Nuclear Information System (INIS)

    The aim of the study was to estimate cancer risk from small doses of ionizing radiation from various sources, including both external and internal exposure. The types of radiation included alpha, gamma, and neutron radiation. A nationwide follow-up study covering the years up to 1992 revealed no significant association between fallout from the Chernobyl accident and incidence of childhood leukemia. An excess of eight cases or more per year could be excluded. However, some indication of an increase was evident in the most heavily affected areas. Furthermore, the risk estimates were in accordance with those reported from Hiroshima and Nagasaki, although the confidence intervals were wide. (282 refs.)

  15. Cancer risk from low doses of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Auvinen, A.

    1997-06-01

    The aim of the study was to estimate cancer risk from small doses of ionizing radiation from various sources, including both external and internal exposure. The types of radiation included alpha, gamma, and neutron radiation. A nationwide follow-up study covering the years up to 1992 revealed no significant association between fallout from the Chernobyl accident and incidence of childhood leukemia. An excess of eight cases or more per year could be excluded. However, some indication of an increase was evident in the most heavily affected areas. Furthermore, the risk estimates were in accordance with those reported from Hiroshima and Nagasaki, although the confidence intervals were wide. (282 refs.).

  16. BYSTANDERS, ADAPTIVE RESPONSES AND GENOMIC INSTABILITY - POTENTIAL MODIFIERS OF LOW-DOSE CANCER RESPONSES.

    Science.gov (United States)

    Bystanders, Adaptive Responses and Genomic Instability -Potential Modifiers ofLow-DoseCancer Responses.There has been a concerted effort in the field of radiation biology to better understand cellularresponses that could have an impact on the estin1ation of cancer...

  17. Chemoradiotherapy with twice-weekly administration of low-dose gemcitabine for locally advanced pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    Hisato Igarashi; Tetsuhide Ito; Ken Kawabe; Terumasa Hisano; Yoshiyuki Arita; Toyoma Kaku; Ryoichi Takayanagi

    2008-01-01

    AIM:To evaluate the chemoradiotherapy for locally advanced pancreatic cancer utilizing low dose gemcitabine as a radiation sensitizer administered twice weekly.METHODS:We performed a retrospective analysis of chemoradiotherapy utilizing gemcitabine administered twice weekly at a dose of 40 mg/m2.After that,maintenance systemic chemotherapy with gemcitabine,at a dose of 1000 mg/m2,was administered weekly for 3 wk with 1-wk rest until disease progression or unacceptable toxicity developed.RESULTS:Eighteen patients with locally advanced unresectable pancreatic cancer were enrolled.Three of those patients could not continue with the therapy;one patient had interstitial pneumonia during radiation therapy and two other patients showed liver metastasis or peritoneal metastasis during an early stage of the therapy.The median survival was 15.0 mo and the overall 1-year survival rate was 60%,while the median progression-free survival was 8.0 too.The subgroup which showed the reduction of tumor development,more than 50% showed a tendency for a better prognosis;however,other parameters including age,gender and performance status did not correlate with survival.The median survival of the groups that died of liver metastasis and peritoneal metastasis were 13.0 mo and 27.7 mo,respectively.CONCLUSION:Chemoradiotherapy with low-dose gemcitabine administered twice weekly could be effective to patients with locally advanced pancreatic cancer;however,patients developing liver metastases had a worse prognosis.Another chemoradiotherapy strategy might be needed for those patients,such as administrating one or two cycles of chemotherapy initially,followed by chemoradiotherapy for the cases with no distant metastases.

  18. Smoking habits in the randomised Danish Lung Cancer Screening Trial with low-dose CT

    DEFF Research Database (Denmark)

    Ashraf, Haseem; Saghir, Zaigham; Dirksen, Asger;

    2014-01-01

    BACKGROUND: We present the final results of the effect of lung cancer screening with low-dose CT on the smoking habits of participants in a 5-year screening trial. METHODS: The Danish Lung Cancer Screening Trial (DLCST) was a 5-year screening trial that enrolled 4104 subjects; 2052 were randomised...... to annual low-dose CT (CT group) and 2052 received no intervention (control group). Participants were current and ex-smokers (≥4 weeks abstinence from smoking) with a tobacco consumption of ≥20 pack years. Smoking habits were determined annually. Missing values for smoking status at the final screening...

  19. Measurement bias dependence of enhanced bipolar gain degradation at low dose rates

    Energy Technology Data Exchange (ETDEWEB)

    Witczak, S.C.; Lacoe, R.C.; Mayer, D.C. [Aerospace Corp., Los Angeles, CA (United States). Electronics Technology Center; Schrimpf, R.D.; Barnaby, H.J.; Galloway, K.F. [Vanderbilt Univ., Nashville, TN (United States). Dept. of Electrical and Computer Engineering; Pease, R.L. [RLP Research, Inc., Albuquerque, NM (United States); Fleetwood, D.M. [Sandia National Labs., Albuquerque, NM (United States)

    1998-03-01

    Oxide trapped charge, field effects from emitter metallization, and high level injection phenomena moderate enhanced gain degradation of lateral pnp transistors at low dose rates. Hardness assurance tests at elevated irradiation temperatures require larger design margins for low power measurement biases.

  20. The evidence for low-dose CT screening of lung cancer.

    Science.gov (United States)

    Ruchalski, Kathleen; Gutierrez, Antonio; Genshaft, Scott; Abtin, Fereidoun; Suh, Robert

    2016-01-01

    Lung cancer remains the leading cause of cancer-related death in the United States. An effective screening tool for early lung cancer detection has long been sought. Early chest radiograph and low-dose computed tomography (LDCT) screening trials were promising and demonstrated increased cancer detection. However, these studies were not able to improve lung cancer mortality. The National Lung Screening Trial resulted in decreased lung cancer mortality with LDCT screening in a high-risk population. Similar trials are currently underway in Europe. With LDCT now being widely implemented, it is paramount for radiologists to understand the evidence for lung cancer screening.

  1. Low-dose aspirin use and the risk of ovarian cancer in Denmark

    DEFF Research Database (Denmark)

    Baandrup, Lone; Kjaer, S K; Olsen, J H;

    2015-01-01

    BACKGROUND: A comprehensive body of evidence has shown that aspirin has cancer-preventive effects, particularly against gastrointestinal cancer, but its effects on the risk of ovarian cancer are less well established. This nationwide case-control study examined the association between low...... were seen for mucinous and endometrioid tumours. CONCLUSION: This nationwide case-control study indicates that low-dose aspirin use may be associated with a reduced risk of epithelial ovarian cancer....... regression was used to calculate odds ratios (ORs) with 95% confidence intervals (CIs) for the association between low-dose aspirin use and the risk of epithelial ovarian cancer, both overall and for specific histological types. RESULTS: For 4103 ovarian cancer cases and 58 706 population controls, the...

  2. The American Brachytherapy Society recommendations for low-dose-rate brachytherapy for carcinoma of the cervix

    International Nuclear Information System (INIS)

    Purpose: This report presents guidelines for using low-dose-rate (LDR) brachytherapy in the management of patients with cervical cancer. Methods: Members of the American Brachytherapy Society (ABS) with expertise in LDR brachytherapy for cervical cancer performed a literature review, supplemented by their clinical experience, to formulate guidelines for LDR brachytherapy of cervical cancer. Results: The ABS strongly recommends that radiation treatment for cervical carcinoma (with or without chemotherapy) should include brachytherapy as a component. Precise applicator placement is essential for improved local control and reduced morbidity. The outcome of brachytherapy depends, in part, on the skill of the brachytherapist. Doses given by external beam radiotherapy and brachytherapy depend upon the initial volume of disease, the ability to displace the bladder and rectum, the degree of tumor regression during pelvic irradiation, and institutional practice. The ABS recognizes that intracavitary brachytherapy is the standard technique for brachytherapy for cervical carcinoma. Interstitial brachytherapy should be considered for patients with disease that cannot be optimally encompassed by intracavitary brachytherapy. The ABS recommends completion of treatment within 8 weeks, when possible. Prolonging total treatment duration can adversely affect local control and survival. Recommendations are made for definitive and postoperative therapy after hysterectomy. Although recognizing that many efficacious LDR dose schedules exist, the ABS presents suggested dose and fractionation schemes for combining external beam radiotherapy with LDR brachytherapy for each stage of disease. The dose prescription point (point A) is defined for intracavitary insertions. Dose rates of 0.50 to 0.65 Gy/h are suggested for intracavitary brachytherapy. Dose rates of 0.50 to 0.70 Gy/h to the periphery of the implant are suggested for interstitial implant. Use of differential source activity or

  3. Gamma radiation at a human relevant low dose rate is genotoxic in mice

    Science.gov (United States)

    Graupner, Anne; Eide, Dag M.; Instanes, Christine; Andersen, Jill M.; Brede, Dag A.; Dertinger, Stephen D.; Lind, Ole C.; Brandt-Kjelsen, Anicke; Bjerke, Hans; Salbu, Brit; Oughton, Deborah; Brunborg, Gunnar; Olsen, Ann K.

    2016-09-01

    Even today, 70 years after Hiroshima and accidents like in Chernobyl and Fukushima, we still have limited knowledge about the health effects of low dose rate (LDR) radiation. Despite their human relevance after occupational and accidental exposure, only few animal studies on the genotoxic effects of chronic LDR radiation have been performed. Selenium (Se) is involved in oxidative stress defence, protecting DNA and other biomolecules from reactive oxygen species (ROS). It is hypothesised that Se deficiency, as it occurs in several parts of the world, may aggravate harmful effects of ROS-inducing stressors such as ionising radiation. We performed a study in the newly established LDR-facility Figaro on the combined effects of Se deprivation and LDR γ exposure in DNA repair knockout mice (Ogg1‑/‑) and control animals (Ogg1+/‑). Genotoxic effects were seen after continuous radiation (1.4 mGy/h) for 45 days. Chromosomal damage (micronucleus), phenotypic mutations (Pig-a gene mutation of RBCCD24‑) and DNA lesions (single strand breaks/alkali labile sites) were significantly increased in blood cells of irradiated animals, covering three types of genotoxic activity. This study demonstrates that chronic LDR γ radiation is genotoxic in an exposure scenario realistic for humans, supporting the hypothesis that even LDR γ radiation may induce cancer.

  4. Method of simulation of low dose rate for total dose effect in 0.18 {mu}m CMOS technology

    Energy Technology Data Exchange (ETDEWEB)

    He Baoping; Yao Zhibin; Guo Hongxia; Luo Yinhong; Zhang Fengqi; Wang Yuanming; Zhang Keying, E-mail: baopinghe@126.co [Northwest Institute of Nuclear Technology, Xi' an 710613 (China)

    2009-07-15

    Three methods for simulating low dose rate irradiation are presented and experimentally verified by using 0.18 {mu}m CMOS transistors. The results show that it is the best way to use a series of high dose rate irradiations, with 100 {sup 0}C annealing steps in-between irradiation steps, to simulate a continuous low dose rate irradiation. This approach can reduce the low dose rate testing time by as much as a factor of 45 with respect to the actual 0.5 rad (Si)/s dose rate irradiation. The procedure also provides detailed information on the behavior of the test devices in a low dose rate environment.

  5. Method of simulation of low dose rate for total dose effect in 0.18 μm CMOS technology

    International Nuclear Information System (INIS)

    Three methods for simulating low dose rate irradiation are presented and experimentally verified by using 0.18 μm CMOS transistors. The results show that it is the best way to use a series of high dose rate irradiations, with 100 0C annealing steps in-between irradiation steps, to simulate a continuous low dose rate irradiation. This approach can reduce the low dose rate testing time by as much as a factor of 45 with respect to the actual 0.5 rad (Si)/s dose rate irradiation. The procedure also provides detailed information on the behavior of the test devices in a low dose rate environment.

  6. More than lung cancer: Automated analysis of low-dose screening CT scans

    NARCIS (Netherlands)

    Mets, O.M.

    2012-01-01

    Smoking is a major health care problem and is projected to cause over 8 million deaths per year worldwide in the coming decades. To reduce lung cancer mortality in heavy smokers, several randomized screening trials were initiated in the past years using screening with low-dose Computed Tomography (C

  7. Weekly low-dose mitoxantrone plus doxorubicin as second-line chemotherapy for advanced breast cancer

    NARCIS (Netherlands)

    M. Bontenbal (Marijke); A.S.Th. Planting (André); C.J. Rodenburg (C.); A. Dees; J. Verweij (Jaap); C.C.M. Bartels (Carina); J. Alexieva-Figusch (Jana); W.L.J. van Putten (Wim); J.G.M. Klijn (Jan)

    1992-01-01

    textabstractWeekly low dose mitoxantrone (3 mg/m2) plus doxorubicin (8 mg/m2) was administered as second-line chemotherapy to 33 patients with advanced breast cancer. Four out of 28 evaluable patients (14%) obtained a partial response with a median duration of 34 weeks (range 18-67+ weeks), while 8

  8. Efficacy of a Low Dose of Estrogen on Antioxidant Defenses and Heart Rate Variability

    Directory of Open Access Journals (Sweden)

    Cristina Campos

    2014-01-01

    Full Text Available This study tested whether a low dose (40% less than the pharmacological dose of 17-β estradiol would be as effective as the pharmacological dose to improve cardiovascular parameters and decrease cardiac oxidative stress. Female Wistar rats (n=9/group were divided in three groups: (1 ovariectomized (Ovx, (2 ovariectomized animals treated for 21 days with low dose (LE; 0.2 mg, and (3 high dose (HE; 0.5 mg 17-β estradiol subcutaneously. Hemodynamic assessment and spectral analysis for evaluation of autonomic nervous system regulation were performed. Myocardial superoxide dismutase (SOD and catalase (CAT activities, redox ratio (GSH/GSSG, total radical-trapping antioxidant potential (TRAP, hydrogen peroxide, and superoxide anion concentrations were measured. HE and LE groups exhibited an improvement in hemodynamic function and heart rate variability. These changes were associated with an increase in the TRAP, GSH/GSSG, SOD, and CAT. A decrease in hydrogen peroxide and superoxide anion was also observed in the treated estrogen groups as compared to the Ovx group. Our results indicate that a low dose of estrogen is just as effective as a high dose into promoting cardiovascular function and reducing oxidative stress, thereby supporting the approach of using low dose of estrogen in clinical settings to minimize the risks associated with estrogen therapy.

  9. Development and characterization of a novel variable low-dose rate irradiator for in vivo mouse studies

    OpenAIRE

    Olipitz, Werner; Hembrador, Sheena; Davidson, Matthew; Yanch, Jacquelyn C; Engelward, Bevin P.

    2010-01-01

    Radiation exposure of humans generally results in low doses delivered at low dose-rate. Our limited knowledge of the biological effects of low dose radiation is mainly based on data from the atomic bomb long-term survivor study (LSS) cohort. However, the total doses and dose-rates in the LSS cohort are still higher than most environmental and occupational exposures in humans. Importantly, the dose-rate is a critical determinant of health risks stemming from radiation exposure. Understanding t...

  10. Oxygen enhancement ratio (OER) and therapeutic gain factor (GF) for californium-252 at low dose rate

    International Nuclear Information System (INIS)

    The potential benefit of the introduction of californium-252 in interstitial and intracavitary therapy is related to the greater efficiency of its neutron emission against anoxic cancer cells. In that respect, the oxygen enhancement ratio (OER) of the 252Cf emission has been determined for a continuous low dose rate irradiation. The biological system is growth inhibition in Vicia faba bean roots. A new Vicia faba ''BelB'' strain has been used, which better tolerates long periods (up to about 10 hours) of anoxia. In a first series of experiments, for a 252Cf (Dsub(n+γ)) dose rate of 0.11 Gy.h-1, an OER of 1.4+-0.1 was observed (the γ contribution Dγ to the total absorbed dose Dsub(n+γ) was 0.35 at the position of the root tips). In a second series of experiments, in somewhat different geometrical conditions with a 252Cf (Dsub(n+γ)) dose rate of 0.13 Gy.h-1, an OER of 1.5+-0.1 was observed (Dγ/Dsub(n+γ)=0.42). The OER values observed for similar irradiation times, with iridium-192 γ-rays, were 2.3+-0.2 and 2.6+-0.1 respectively, which leads to therapeutic gain factors (GF) of 1.6 and 1.7 respectively. These GF values are slightly lower than those previously obtained (GF=1.8) on the same system, with d(50)-Be p(75)-Be and 15 MeV neutron beams

  11. Cancer risk at low doses of ionizing radiation: artificial neural networks inference from atomic bomb survivors

    OpenAIRE

    Sasaki, Masao S.; Tachibana, Akira; Takeda, Shunichi

    2013-01-01

    Cancer risk at low doses of ionizing radiation remains poorly defined because of ambiguity in the quantitative link to doses below 0.2 Sv in atomic bomb survivors in Hiroshima and Nagasaki arising from limitations in the statistical power and information available on overall radiation dose. To deal with these difficulties, a novel nonparametric statistics based on the ‘integrate-and-fire’ algorithm of artificial neural networks was developed and tested in cancer databases established by the R...

  12. Cancer risk at low doses of ionizing radiation: artificial neural networks inference from atomic bomb survivors.

    OpenAIRE

    Sasaki, Masao S.; Tachibana, Akira; Takeda, Shunichi

    2014-01-01

    Cancer risk at low doses of ionizing radiation remains poorly defined because of ambiguity in the quantitative link to doses below 0.2 Sv in atomic bomb survivors in Hiroshima and Nagasaki arising from limitations in the statistical power and information available on overall radiation dose. To deal with these difficulties, a novel nonparametric statistics based on the 'integrate-and-fire' algorithm of artificial neural networks was developed and tested in cancer databases established by the R...

  13. Relationship of HepG2 cell sensitivity to continuous low dose-rate irradiation with ATM phosphorylation

    Institute of Scientific and Technical Information of China (English)

    Quelin Mei; Jianyong Yang; Duanming Du; Zaizhong Cheng; Pengcheng liu

    2008-01-01

    Objective: To investigate the change of ATM phosphorylation in HepG2 cells and its effect on HepG2 cell survival under a continuous low dose-rate irradiation.Methods: HepG2 cells were exposed to equivalent doses of irradiation delivered at either a continuous low dose-rate (7.76 cGy/h) or a high dose-rate (4500 cGy/h).The ATM phosphorylated proteins and surviving fraction of HepG2 cell after low dose-rate irradiation were compared with that after equivalent doses of high dose-rate irradiation.Results: The phosphorylation of ATM protein was maximal at 0.5 Gy irradiation delivered at either a high dose-rate or a continuous low dose-rate.As the radiation dose increased, the phosphorylation of ATM protein decreased under continuous low dose-rate irradiation.However, the phosphorylation of ATM protein was remained stable under high dose-rate irradiation.When the phosphorylation of ATM protein under continuous low dose-rate irradiation was equal to that under high dose-rate irradiation, there was no significant difference in the surviving fraction of HepG2 cells between two ir-radiation methods (P>0.05).When the phosphorylation of ATM protein significantly decreased after continuous low dose-rate irradiation compared with that after high dose-rate irradiation, increased amounts of cell killing was found in low dose-rate irradiation (P<0.01).Conclusion: Continuous low dose-rate irradiation increases HepG2 cells radiosensitivity compared with high dose-rate irradiation.The increased amounts of cell killing following continuous low dose-rate exposures are associated with reduced ATM phosphorylated protein.

  14. A decrease in lung cancer mortality following the introduction of low-dose chest CT screening in Hitachi, Japan.

    Science.gov (United States)

    Nawa, Takeshi; Nakagawa, Tohru; Mizoue, Tetsuya; Kusano, Suzushi; Chonan, Tatsuya; Hayashihara, Kenji; Suito, Tetsushi; Endo, Katsuyuki

    2012-12-01

    Recent US clinical trial demonstrated that CT screening prevents lung cancer death among high risk individuals. However, it remains unclear whether wide implementation of low-dose CT screening for lung cancer can decrease mortality in the community. Among residents in Hitachi City (Japan), where nearly 40% of inhabitants aged 50-69 years were estimated to have participated in the screening at least once from 1998 through 2009, the trend of lung cancer mortality was described in relation to the timing of implementation of the CT screening. Cancer mortality data were obtained from regional cancer registry and standardized mortality ratio (SMR) of lung cancer was calculated for each 5-year period during 1995-2009. In both men and women aged 60 years or older, age-specific lung cancer mortality rates were generally lower during 2005-2009 as compared with those during 1995-2004. For combined men and women aged 50-79 years, SMR was nearly unity prior to or during introductory phase of CT screening and during early period of implementation; however, it was significantly decreased during 2005-2009, well after the implementation of CT screening, with SMR (95% confidence interval) being 0.76 (0.67-0.86). Results suggest that wide implementation of low-dose chest CT screening may decrease lung cancer mortality in the community 4-8 years after introduction of the screening.

  15. Early detection of lung cancer using low-dose CT: an update

    International Nuclear Information System (INIS)

    Lung cancer is the leading cause of death from malignancy. Due to a lack of early symptoms patients usually undergo therapy at advanced tumor stages when prognosis is poor. Feasibility studies of low-dose spiral CT screening of heavy smokers have shown that many small, resectable lung cancers can be diagnosed at early stages using simple diagnostic algorithms based on size and attenuation of detected pulmonary nodules with a small proportion of invasive procedures for benign lesions. Preliminary results of repeat screening confirms small size and favourable stage distribution of detected cancers, using even simpler diagnostic algorithms: additional diagnostic procedures are only required in new or growing nodules whereas follow-up with low-dose CT is sufficient in nodules that appear unchanged to exclude slow growth. However, mortality reduction by lung cancer screening with low-dose CT has yet to be demonstrated. Several randomised controlled trials are under way to assess possible mortality reduction by comparison of mortalities in a screening group and a control group. It is hoped that through international cooperation data from these trials can be pooled to allow for statistically significant conclusions as early as possible. (orig.)

  16. Multi-Level Effects of Low Dose Rate Ionizing Radiation on Southern Toad, Anaxyrus [Bufo] terrestris.

    Directory of Open Access Journals (Sweden)

    Karolina Stark

    Full Text Available Despite their potential vulnerability to contaminants from exposure at multiple life stages, amphibians are one of the least studied groups of vertebrates in ecotoxicology, and research on radiation effects in amphibians is scarce. We used multiple endpoints to assess the radiosensitivity of the southern toad (Anaxyrus [Bufo] terrestris during its pre-terrestrial stages of development -embryonic, larval, and metamorphic. Toads were exposed, from several hours after oviposition through metamorphosis (up to 77 days later, to four low dose rates of 137Cs at 0.13, 2.4, 21, and 222 mGy d-1, resulting in total doses up to 15.8 Gy. Radiation treatments did not affect hatching success of embryos, larval survival, or the length of the larval period. The individual family variation in hatching success of embryos was larger than the radiation response. In contrast, newly metamorphosed individuals from the higher dose-rate treatments had higher mass and mass/length body indices, a measure which may relate to higher post-metamorphic survival. The increased mass and index at higher dose rates may indicate that the chronic, low dose rate radiation exposures triggered secondary responses. Additionally, the increases in growth were linked to a decrease in DNA damage (as measured by the Comet Assay in red blood cells at a dose rate of 21 mGy d-1 and a total dose of 1.1 Gy. In conclusion, the complex effects of low dose rates of ionizing radiation may trigger growth and cellular repair mechanisms in amphibian larvae.

  17. Multi-level effects of low dose rate ionizing radiation on southern toad, Anaxyrus [Bufo] terrestris

    International Nuclear Information System (INIS)

    Despite their potential vulnerability to contaminants from exposure at multiple life stages, amphibians are one of the least studied groups of vertebrates in ecotoxicology, and research on radiation effects in amphibians is scarce. We used multiple endpoints to assess the radiosensitivity of the southern toad (Anaxyrus [Bufo] terrestris) during its pre-terrestrial stages of development -embryonic, larval, and metamorphic. Toads were exposed, from several hours after oviposition through metamorphosis (up to 77 days later), to four low dose rates of 137Cs at 0.13, 2.4, 21, and 222 mGy d-1, resulting in total doses up to 15.8 Gy. Radiation treatments did not affect hatching success of embryos, larval survival, or the length of the larval period. The individual family variation in hatching success of embryos was larger than the radiation response. In contrast, newly metamorphosed individuals from the higher dose-rate treatments had higher mass and mass/length body indices, a measure which may relate to higher post-metamorphic survival. The increased mass and index at higher dose rates may indicate that the chronic, low dose rate radiation exposures triggered secondary responses. Additionally, the increases in growth were linked to a decrease in DNA damage (as measured by the Comet Assay) in red blood cells at a dose rate of 21mGy d-1 and a total dose of 1.1 Gy. In conclusion, the complex effects of low dose rates of ionizing radiation may trigger growth and cellular repair mechanisms in amphibian larvae

  18. Lung cancer screening with low-dose computed tomography: Canadian experience

    International Nuclear Information System (INIS)

    In 2003, the department of medical imaging at the University Health Network in Toronto, Ontario, became the first Canadian site of the International Early Lung Cancer Action Program (I-ELCAP). We report the results from the first 1000 baseline studies. Between June 2003 and December 2005, we enrolled 1000 high-risk smokers (that is, smokers with a history of a least 10 pack years, or the equivalent of one pack daily for 10 years), aged 55 years or older. A low-dose helical computed tomography (CT) (40 to 60 mA, 120 kV) was performed with 1.0mm to 1.25 collimation. Nodules found at baseline were followed according to the I-ELCAP protocol: 1) no noncalcified nodules (NCNs) or NCNs ≤ 4 mm or nonsolid nodules < 8 mm, annual repeat: 2) NCNs ≥ 5mm or nonsolid nodules ≥ 8 mm, 3-month follow up: or 3) nonsolid nodules ≥ 15 mm, antibiotics and 1-month follow-up. The first 100 study participants were aged 63 years, standard deviation (SD) 6 years, with a smoking history of 38 pack years, SD 22 pack years; 662 (66%) were former smokers, and 338 (34%) were current smokers; 453 (45%) were men, and 547 (55%) were women. Of the participants, 256 (26%) had a positive baseline low-dose computed tomography (LCDT) scan; 227 (23%) were followed after 3 months and 15 (1.6%) after 1 month; 7 (0.7%) received a contrast-enhanced CT and 6 (0.6%) an immediate CT-guided biopsy. Twenty-six invasive procedures were performed: 22 CT-guided biopsies, 1 ultrasound-guided lymph node metastasis biopsy, 1 bronchoscopic biopsy and 2 surgeries. The malignancy rate of the invasive procedures was 85%. Overall, the malignancy prevalence is 2.2%. Of the malignancies, 20 are lung carcinomas: 19 non-small-cell lung carcinomas (NSCLCs) (14 adenocarcinoma or bronchioalveolar carcinoma [BAC], 4 squamous carcinoma, and 1 large-cell carcinoma) and 1 small-cell carcinoma; 15 (78%) of the NSCLCs are Stage 1. Fourteen patients underwent surgery (1 pneumonectomy, 9 lobectomies, and 4 segmentectomies). Our

  19. Effects of emitter junction and passive base region on low dose rate effect in bipolar devices

    International Nuclear Information System (INIS)

    Low dose rate effect in bipolar devices consists in the increase of peripheral surface recombination current with dose rate decrease. This is due to the more rapid positive oxide charge and interface trap density build-up as the dose rate becomes lower. High dose rate elevated temperature irradiation is proposed for simulation if the low dose rate effect. In the present we tried to separate the effect of radiation-induced charge in the thick passivation oxide over the emitter junction and passive base regions of npn bipolar transistor. Its goal is to improve bipolar device design for use in space environments and nuclear installations. Three experiments were made during this work. 1. Experiment on radiation-induced charge neutralization (RICN) effect under elevated temperature was performed to show transistor degradation dependence on emitter-base bias. 2. High dose rate elevated and room temperature irradiation of bipolar transistors were performed to separate effects of emitter-junction and passive base regions. 3. Pre- and post- irradiation hydrogen ambient storage was used to investigate its effect on radiation-induced charge build-up over the passive base region. All experiments were performed with npn and pnp transistors. (authors)

  20. The biochemical recurrence-free rate in patients who underwent prostate low-dose-rate brachytherapy, using two different definitions

    International Nuclear Information System (INIS)

    To assess the biochemical recurrence (BCR)-free rate in patients who underwent prostate low-dose-rate brachytherapy (LDR-brachytherapy), using two different definitions (Phoenix definition and PSA ≥ 0.2 ng/mL). Two hundreds and three patients who were clinically diagnosed with localized prostate cancer (cT1c-2cN0M0) and underwent LDR-brachytherapy between July 2004 and September 2008 were enrolled. The median follow-up period was 72 months. We evaluated the BCR-free rate using the Phoenix definition and the PSA cut-off value of 0.2 ng/mL, as in the definition for radical prostatectomy. To evaluate an independent variable that can predict BCR, Cox’s proportional hazard regression analysis was carried out. The BCR-free rate in patients using the Phoenix definition was acceptable (5-year: 92.8%). The 5- year BCR-free rate using the strict definition (PSA ≥ 0.2 ng/mL) was 74.1%. Cox’s proportional hazard regression analysis showed that a higher biological effective dose (BED) of ≥180 Gy2 was the only independent variable that could predict BCR (HR: 0.570, 95% C.I.: 0.327-0.994, p = 0.048). Patients with a higher BED (≥180 Gy2) had a significantly higher BCR-free rate than those with a lower BED (<180 Gy2) (5-year BCR-free rate: 80.5% vs. 67.4%). A higher BED ≥180 Gy2 promises a favorable BCR-free rate, even if the strict definition is adopted

  1. Comparison in vivo Study of Genotoxic Action of High- Versus Very Low Dose-Rate γ-Irradiation

    OpenAIRE

    A. N. Osipov; Klokov, D. Y.; Elakov, A. L.; Rozanova, O M; Zaichkina, S. I.; Aptikaeva, G. F.; Akhmadieva, A. Kh.

    2004-01-01

    The aim of the present study was to compare genotoxicity induced by high- versus very low dose-rate exposure of mice to γ-radiation within a dose range of 5 to 61 cGy using the single-cell gel electrophoresis (comet) assay and the micronucleus test. CBA/lac male mice were irradiated at a dose rate of 28.2 Gy/h (high dose rate) or 0.07 mGy/h (very low dose rate). The comet assay study on spleen lymphocytes showed that very low dose-rate irradiation resulted in a statistically significant incre...

  2. OER and RBE for 125I and 192Ir at low dose rate on mammalian cells

    International Nuclear Information System (INIS)

    The oxygen enhancement ratio (OER) for 125I and 192Ir as well as the relative biological effectiveness (RBE) at low dose rates (40-80 cGy h-1) were determined for B16 melanoma cells in culture. The OER was found to be 2.1±0.03 for 125I and 2.7±0.04 for 192Ir. The RBE for 125I relative to 192Ir was determined as 1.8±0.03 under aerated conditions and as 2.4±0.03 under hypoxia. 18 refs.; 5 figs.; 1 table

  3. Whole-body low dose radiation promotes the efficiency of conventional radiotherapy of cancer

    International Nuclear Information System (INIS)

    Full text: Radiotherapy is the most commonly used local treatment of cancer. However, the large dose needed for local control often limits its successful use. In view of the stimulatory effect of low dose radiation (LDR) on anticancer immunity an experimental study of the effect of whole-body LDR on the outcome of conventional local radiotherapy of cancer was designed with an aim at reducing the total dose and promoting treatment efficiency. With a Lewis lung cancer model in mice it was observed that a regimen of 2 Gy x 3 per week for 2 weeks with a total local dose of 12 Gy resulted in only 23% reduction of tumor volume in 1 month as| compared with untreated control, while substitution of the second, third, fifth and sixth doses of 2 Gy with whole-body irradiation (WBI) of 0.075 Gy with a total local dose of 4 Gy plus 0.3 Gy WBI caused a 69% reduction of tumor volume in the same period. Since gene therapy with Egr-IL-18-B7.1 in combination with local X-rays showed better control of mouse I melanoma than local radiotherapy alone, a trial was made with this plasmid in the above Lewis lung cancer model. The results showed that in the 12 Gy protocol the tumor volume) reduction was 42% and in the 4 Gy local plus 0.3 Gy WBI protocol the tumor volume reduction was 77% in one month. This better control of cancer growth was apparently related to the stimulation of anticancer immunity by WBI with low doses and facilitation of IL-18) and B7.1 expression from the cancer cells in the gene therapy group resulting in up-regulation of immunity. It is concluded that WBI with low doses in combination with conventional radiotherapy exerts a significant promoting effect manifested in reduction in local radiation dose and improvement in tumor control

  4. Liver cancer stem cells are selectively enriched by low-dose cisplatin

    Directory of Open Access Journals (Sweden)

    H. Zhang

    2014-06-01

    Full Text Available Accumulating evidence has indicated the importance of cancer stem cells in carcinogenesis. The goal of the present study was to determine the effect of low-dose cisplatin on enriched liver cancer stem cells (LCSCs. Human hepatoblastoma HepG2 cells were treated with concentrations of cisplatin ranging from 1 to 5 μg/mL. Cell survival and proliferation were evaluated using a tetrazolium dye (MTT assay. LCSCs were identified using specific markers, namely aldehyde dehydrogenase-1 (ALDH1 and CD133. The percentage of ALDH1+ or CD133+ cells was examined by flow cytometric analysis. The expression of ALDH1 and/or CD133 in HepG2 cells was determined by immunocytochemical analysis. Low-dose cisplatin treatment significantly decreased cell survival in HepG2 cells after 24 or 72 h. However, the percentage of LCSCs in the surviving cells was greatly increased. The percentage of ALDH1+ or CD133+ cells was increased in a time- and dose-dependent manner after treatment with 1-4 μg/mL cisplatin, whereas 5 μg/mL cisplatin exposure slightly reduced the number of positive cells. These findings indicate that low-dose cisplatin treatment may efficiently enrich the LCSC population in HepG2 cells.

  5. Chromosome aberrations and micronucleus in continuously irradiated mice for a low dose rate of {sup 137}Cs {gamma}-rays

    Energy Technology Data Exchange (ETDEWEB)

    Izumi, Jun; Yanai, Takanori; Shirata, Katsutoshi; Tanaka, Kimio; Sato, Fumiaki [Inst. for Environmental Sciences, Rokkasho, Aomori (Japan)

    2002-07-01

    Delayed chromosomal instability is developed by radiation after several cell divisions in cultured rodent and human cells. The genetic instability might be related to cancer development and it has been mainly found in cultured rodent and human cells irradiated at high dose rate. It has not been well studied whether the genetic instability is induced by prolonged irradiation with low dose rate in vivo or not. Mice irradiated with 20 mGy/day for 5-8 Gy were analyzed by FISH to estimate the chromosome aberration rate and micronucleus incidence in spleen and bone marrow cells. Spleen cells in mice exposed to 8 Gy have higher incidence of monosomy and trisomy than non-exposed mice. The number of cells with 2-4 micronuclei in 10,000 scored spleen cells is also higher in 5-8 Gy exposed mice. These numerical chromosome aberrations are not induced directly by radiation exposure. These results indicate that prolonged {sup 137}Cs {gamma} ray-irradiation with low dose rates of 20 mGy/day induces delayed chromosome instability in mice. (author)

  6. Low Dose Rate Radiosensitization of Hepatocellular Carcinoma In Vitro and in Patients

    Directory of Open Access Journals (Sweden)

    Kyle C. Cuneo

    2014-08-01

    Full Text Available Transarterial radioembolization (TARE with 90Y microspheres delivers low dose rate radiation (LDR to intrahepatic tumors. In the current study, we examined clonogenic survival, DNA damage, and cell cycle distribution in hepatocellular carcinoma (HCC cell lines treated with LDR in combination with varying doses and schedules of 5-fluorouracil (5-FU, gemcitabine, and sorafenib. Radiosensitization was seen with 1 to 3 μM 5-FU (enhancement ratio 2.2–13.9 and 30 to 100 nM gemcitabine (enhancement ratio 1.9–2.9 administered 24 hours before LDR (0.26 Gy/h to 4.2 Gy. Sorafenib radiosensitized only at high concentrations (3–10 μM when administered after LDR. For a given radiation dose, greater enhancement was seen with LDR compared to standard dose rate therapy. Summarizing our clinical experience with low dose rate radiosensitization, 13 patients (5 with HCC, 8 with liver metastases were treated a total of 16 times with TARE and concurrent gemcitabine. Six partial responses and one complete response were observed with a median time to local failure of 7.1 months for all patients and 9.9 months for patients with HCC. In summary, HCC is sensitized to LDR with clinically achievable concentrations of gemcitabine and 5-FU in vitro. Encouraging responses were seen in a small cohort of patients treated with TARE and concurrent gemcitabine. Future studies are needed to validate the safety and efficacy of this approach.

  7. Reviewing risks and benefits of low-dose computed tomography screening for lung cancer.

    Science.gov (United States)

    Chopra, Ishveen; Chopra, Avijeet; Bias, Thomas K

    2016-01-01

    Lung cancer is the third most common cancer among men and women and is one of the leading causes of cancer-related mortality. Diagnosis at an early stage has been suggested crucial for improving survival in individuals at high-risk of lung cancer. One potential facilitator to early diagnosis is low-dose computed tomography (LDCT). The United States Preventive Services Task Force guidelines call for annual LDCT screening for individuals at high-risk of lung cancer. This recommendation was based on the effectiveness of LDCT in early diagnosis of lung cancer, as indicated by the findings from the National Lung Screening Trial conducted in 2011. Although lung cancer accounts for more than a quarter of all cancer deaths in the United States and LDCT screening shows promising results regarding early lung cancer diagnosis, screening for lung cancer remains controversial. There is uncertainty about risks, cost-effectiveness, adequacy of evidence, and application of screening in a clinical setting. This narrative review provides an overview of risks and benefits of LDCT screening for lung cancer. Further, this review discusses the potential for implementation of LDCT in clinical setting. PMID:26680693

  8. Success rates for computed tomography-guided musculoskeletal biopsies performed using a low-dose technique

    Energy Technology Data Exchange (ETDEWEB)

    Motamedi, Kambiz; Levine, Benjamin D.; Seeger, Leanne L.; McNitt-Gray, Michael F. [UCLA Health System, Radiology, Los Angeles, CA (United States)

    2014-11-15

    To evaluate the success rate of a low-dose (50 % mAs reduction) computed tomography (CT) biopsy technique. This protocol was adopted based on other successful reduced-CT radiation dose protocols in our department, which were implemented in conjunction with quality improvement projects. The technique included a scout view and initial localizing scan with standard dose. Additional scans obtained for further guidance or needle adjustment were acquired by reducing the tube current-time product (mAs) by 50 %. The radiology billing data were searched for CT-guided musculoskeletal procedures performed over a period of 8 months following the initial implementation of the protocol. These were reviewed for the type of procedure and compliance with the implemented protocol. The compliant CT-guided biopsy cases were then retrospectively reviewed for patient demographics, tumor pathology, and lesion size. Pathology results were compared to the ultimate diagnoses and were categorized as diagnostic, accurate, or successful. Of 92 CT-guided procedures performed during this period, two were excluded as they were not biopsies (one joint injection and one drainage), 19 were excluded due to non-compliance (operators neglected to follow the protocol), and four were excluded due to lack of available follow-up in our electronic medical records. A total of 67 compliant biopsies were performed in 63 patients (two had two biopsies, and one had three biopsies). There were 32 males and 31 females with an average age of 50 (range, 15-84 years). Of the 67 biopsies, five were non-diagnostic and inaccurate and thus unsuccessful (7 %); five were diagnostic but inaccurate and thus unsuccessful (7 %); 57 were diagnostic and accurate thus successful (85 %). These results were comparable with results published in the radiology literature. The success rate of CT-guided biopsies using a low-dose protocol is comparable to published rates for conventional dose biopsies. The implemented low-dose protocol

  9. Low-dose rate telecobalt therapy as a boost against esophageal carcinomas

    International Nuclear Information System (INIS)

    The results of treatment of 54 esophageal carcinomas managed with low-dose-rate telecobalt therapy (LDRT) as a boost were compared with those of 89 esophageal carcinomas treated with conventionally fractionated irradiation alone (CFI). The LDRT (1 Gy/hr, 5-7 Gy/day, to a total dose of 14-20 Gy) was boosted about 10 days after the CFI dose of 60 Gy. Although the LDRT group included more advanced cases than the CFI group, local effects and survival rate of the LDRT group, especially those with tumorous X-P and serrated types, were better than those of the CFI group. Late complications were more severe in the LDRT group. However, they were acceptable when the total dose in the LDRT group was brought under 80 Gy. (author)

  10. Evaluation of protracted low dose rate irradiation from an acute dose survival curve

    International Nuclear Information System (INIS)

    A method of transformation from an acute survival curve to a protracted low dose rate survival curve based on the concept of the dose equivalent sublethal damage advanced by Oliver is introduced. The transformation was done by solving a differential equation which was formulated between the slope of both survival curves and which was able to be applied to the situation where the dose rate might change with time, e.g., in using short-life radioisotopes or the complexity of the recovery of sub-lethal damage. The effects of the short-life radioisotopes (radon seeds and radiogold grains) in radiotherapy model; our data are compared with the data obtained by Orton

  11. Emesis as a Screening Diagnostic for Low Dose Rate (LDR) Total Body Radiation Exposure.

    Science.gov (United States)

    Camarata, Andrew S; Switchenko, Jeffrey M; Demidenko, Eugene; Flood, Ann B; Swartz, Harold M; Ali, Arif N

    2016-04-01

    Current radiation disaster manuals list the time-to-emesis (TE) as the key triage indicator of radiation dose. The data used to support TE recommendations were derived primarily from nearly instantaneous, high dose-rate exposures as part of variable condition accident databases. To date, there has not been a systematic differentiation between triage dose estimates associated with high and low dose rate (LDR) exposures, even though it is likely that after a nuclear detonation or radiologic disaster, many surviving casualties would have received a significant portion of their total exposure from fallout (LDR exposure) rather than from the initial nuclear detonation or criticality event (high dose rate exposure). This commentary discusses the issues surrounding the use of emesis as a screening diagnostic for radiation dose after LDR exposure. As part of this discussion, previously published clinical data on emesis after LDR total body irradiation (TBI) is statistically re-analyzed as an illustration of the complexity of the issue and confounding factors. This previously published data includes 107 patients who underwent TBI up to 10.5 Gy in a single fraction delivered over several hours at 0.02 to 0.04 Gy min. Estimates based on these data for the sensitivity of emesis as a screening diagnostic for the low dose rate radiation exposure range from 57.1% to 76.6%, and the estimates for specificity range from 87.5% to 99.4%. Though the original data contain multiple confounding factors, the evidence regarding sensitivity suggests that emesis appears to be quite poor as a medical screening diagnostic for LDR exposures. PMID:26910032

  12. Non-solid lung nodules on low-dose computed tomography : comparison of detection rate between 3 visualization techniques

    NARCIS (Netherlands)

    Scholten, Ernst Th.; Mali, Willem P. Th. M.; Prokop, Mathias; van Ginneken, Bram; Glandorf, Ron; van Klaveren, Rob; Oudkerk, Matthijs; de Jong, Pim A.

    2013-01-01

    Objective: To compare various visualization techniques for the detection of non-solid nodules in low-dose lung cancer screening computed tomography (CT) scans. Methods: An enriched sample of 216 male lung cancer screening subjects aged 60.4 +/- 6.0 years was used. Two blinded independent readers sea

  13. Measurement uncertainty analysis of low-dose-rate prostate seed brachytherapy: post-implant dosimetry.

    Science.gov (United States)

    Gregory, Kent J; Pattison, John E; Bibbo, Giovanni

    2015-03-01

    The minimal dose covering 90 % of the prostate volume--D 90--is arguably the most important dosimetric parameter in low-dose-rate prostate seed brachytherapy. In this study an analysis of the measurement uncertainties in D 90 from low-dose-rate prostate seed brachytherapy was conducted for two common treatment procedures with two different post-implant dosimetry methods. The analysis was undertaken in order to determine the magnitude of D 90 uncertainty, how the magnitude of the uncertainty varied when D 90 was calculated using different dosimetry methods, and which factors were the major contributors to the uncertainty. The analysis considered the prostate as being homogeneous and tissue equivalent and made use of published data, as well as original data collected specifically for this analysis, and was performed according to the Guide to the expression of uncertainty in measurement (GUM). It was found that when prostate imaging and seed implantation were conducted in two separate sessions using only CT images for post-implant analysis, the expanded uncertainty in D 90 values were about 25 % at the 95 % confidence interval. When prostate imaging and seed implantation were conducted during a single session using CT and ultrasound images for post-implant analysis, the expanded uncertainty in D 90 values were about 33 %. Methods for reducing these uncertainty levels are discussed. It was found that variations in contouring the target tissue made the largest contribution to D 90 uncertainty, while the uncertainty in seed source strength made only a small contribution. It is important that clinicians appreciate the overall magnitude of D 90 uncertainty and understand the factors that affect it so that clinical decisions are soundly based, and resources are appropriately allocated.

  14. Simple pulmonary eosinophilia detected at low-dose CT for lung cancer screening

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Kyung Nyeo; Bae, Kyung Soo; Kim, Ho Cheol [Gyeongsang National University Hospital, Jinju (Korea, Republic of)] (and others)

    2006-05-15

    The aim of this study was to evaluate the frequency, radiologic findings and clinical significance of the simple pulmonary eosinophilia (SPE) that was diagnosed among the asymptomatic patients who underwent low-dose CT scans for the early detection of lung cancer. From June 2003 to May 2005, 1,239 asymptomatic patients (1,275 examinations) who visited the health promotion center in our hospital and who underwent low-dose CT were enrolled in this study. SPE was defined as the presence of > 500 eosinophils per microliter of peripheral blood and the presence of abnormal parenchymal lesions such as nodules, airspace consolidation or areas of ground-glass attenuation (GGA) on CT, and there was spontaneous resolution or migration of the lesions on the follow-up examination. We analyzed the CT findings of SPE and we investigated the relationship between the occurrence of SPE and the season, smoking and the presence of parasite infestation. 36 patients were finally diagnosed as having SPE; this was 24% of the 153 patients who were diagnosed with parasite infestation and 2.8% of the total low-dose CT scans. These 36 patients consisted of 31 men and 5 women with a mean age 45.7 years. There was no significant relationship between SPE and the presence of parasite infestation, smoking or gender. Among the patients with peripheral blood eosinophilia, the eosinophil count was significantly higher in the patients with SPE than that in the patients without pulmonary infiltration ({rho} < 0.05). SPE more frequently occurred in winter and spring than in summer and autumn ({rho} < 0.05). The CT findings were single or multiple nodules in 18 patients, nodules and focal GGA in 9 patients and GGA only in 9 patients. Most of the nodules were less than 10 mm (88%, 49/56) in diameter and they showed an ill-defined margin (82%, n = 46); 30% of the nodules (n = 17) showed a halo around them. Simple pulmonary eosinophilia can be suggested as the cause if single or multiple ill-defined nodules

  15. Effect of low doses of estradiol and tamoxifen on breast cancer cell karyotypes.

    Science.gov (United States)

    Rondón-Lagos, Milena; Rangel, Nelson; Di Cantogno, Ludovica Verdun; Annaratone, Laura; Castellano, Isabella; Russo, Rosalia; Manetta, Tilde; Marchiò, Caterina; Sapino, Anna

    2016-08-01

    Evidence supports a role of 17&-estradiol (E2) in carcinogenesis and the large majority of breast carcinomas are dependent on estrogen. The anti-estrogen tamoxifen (TAM) is widely used for both treatment and prevention of breast cancer; however, it is also carcinogenic in human uterus and rat liver, highlighting the profound complexity of its actions. The nature of E2- or TAM-induced chromosomal damage has been explored using relatively high concentrations of these agents, and only some numerical aberrations and chromosomal breaks have been analyzed. This study aimed to determine the effects of low doses of E2 and TAM (10(&8 )mol L(&1) and 10(&6 )mol L(&1) respectively) on karyotypes of MCF7, T47D, BT474, and SKBR3 breast cancer cells by comparing the results of conventional karyotyping and multi-FISH painting with cell proliferation. Estrogen receptor (ER)-positive (+) cells showed an increase in cell proliferation after E2 treatment (MCF7, T47D, and BT474) and a decrease after TAM treatment (MCF7 and T47D), whereas in ER& cells (SKBR3), no alterations in cell proliferation were observed, except for a small increase at 96 h. Karyotypes of both ER+ and ER& breast cancer cells increased in complexity after treatments with E2 and TAM leading to specific chromosomal abnormalities, some of which were consistent throughout the treatment duration. This genotoxic effect was higher in HER2+ cells. The ER&/HER2+ SKBR3 cells were found to be sensitive to TAM, exhibiting an increase in chromosomal aberrations. These in vitro results provide insights into the potential role of low doses of E2 and TAM in inducing chromosomal rearrangements in breast cancer cells. PMID:27357940

  16. Lung cancer screening beyond low-dose computed tomography: the role of novel biomarkers.

    Science.gov (United States)

    Hasan, Naveed; Kumar, Rohit; Kavuru, Mani S

    2014-10-01

    Lung cancer is the most common and lethal malignancy in the world. The landmark National lung screening trial (NLST) showed a 20% relative reduction in mortality in high-risk individuals with screening low-dose computed tomography. However, the poor specificity and low prevalence of lung cancer in the NLST provide major limitations to its widespread use. Furthermore, a lung nodule on CT scan requires a nuanced and individualized approach towards management. In this regard, advances in high through-put technology (molecular diagnostics, multi-gene chips, proteomics, and bronchoscopic techniques) have led to discovery of lung cancer biomarkers that have shown potential to complement the current screening standards. Early detection of lung cancer can be achieved by analysis of biomarkers from tissue samples within the respiratory tract such as sputum, saliva, nasal/bronchial airway epithelial cells and exhaled breath condensate or through peripheral biofluids such as blood, serum and urine. Autofluorescence bronchoscopy has been employed in research setting to identify pre-invasive lesions not identified on CT scan. Although these modalities are not yet commercially available in clinic setting, they will be available in the near future and clinicians who care for patients with lung cancer should be aware. In this review, we present up-to-date state of biomarker development, discuss their clinical relevance and predict their future role in lung cancer management.

  17. Computer-aided detection of nodule in low-dose CT screening for lung cancer

    International Nuclear Information System (INIS)

    Objective: To evaluate the performance of computer-aided detection (CAD) system for detection of pulmonary nodules in 64-slice low-dose CT screening and to investigate whether CAD can improve the performance of radiologists in detecting pulmonary nodules. Methods: One hundred low-dose screening CT examinations were randomly selected from the database containing 578 consecutive cases between Jun 2007 and Jun 2008. All the examinations were performed on a 64-MSCT scanner with the exposure of 120 kVp, 30 or 40 mA, or automatic exposure control. Before the study started, the screening reports had been made with double reading by two radiologists. All the selected images were analyzed with the lung VCAR software from GE Healthcare with a nodule diameter threshold 3.0 mm. All discrepancies between the screening reports and the CAD results were reviewed and the true non-calcified nodules were determined in consensus by two experienced chest radiologists. Detected nodules were classified by density, size and location.The performance of the double reading and the CAD system were compared and analyzed statistically. McNemar-Bowker test was used for the statistical analysis. Results: A total of 257 true noncalcified nodules were determined in all 100 low-dose screening CT examinations. The detection rate of CAD system was 91.1% (234/257), with the missed rate of 8.9% (23/257). Twenty three nodules were missed by CAD, in which 10 were solid with the diameter ranged from 2.4 to 6.0 mm, and 13 were nonsolid with the diameter ranged from 2.1 to 8.6 mm.Of the 23 nodules, 17 were located in the outer zones of lungs and 6 in the inner zones. The double reading showed a detection rate of 59.1% (152/257) and a missed rate of 40.9% (105/257), which was significantly lower than CAD. The diameter of all the 105 missed nodules by radiologists were ranged from 2.4 to 11.8 mm, in which 94 nodules were solid, 10 were partly solid and 1 was nonsolid, with 69 located in outer zones of lungs

  18. Response to the argument on the risk of cancer with chest CT screening. Is low-dose chest CT safe?

    International Nuclear Information System (INIS)

    The steady increase in the annual number of chest CT screening has become a worldwide concern because of its associated risk of lung cancer. Epidemiological studies, however, have shown that repeated exposure to low-dose radiation does not increase the risk of lung cancer. In addition, a recent randomized controlled study on chest CT screening has shown its usefulness for reducing lung cancer mortality. We reviewed the risk of lung cancer after repeated exposure to low-dose radiation, the efficacy of chest CT screening, and device technology for reducing the irradiation dose. (author)

  19. Low dose radiation hypersensitivity and clustered DNA damages in human fibroblasts exposed to low dose and dose rate protons or 137CS y-rays

    Energy Technology Data Exchange (ETDEWEB)

    Bennett P. V.; Bennett, P.V.; Keszenman, D.J.; Johnson, A.M.; Sutherland, B.M.; Wilson, P.F.

    2013-05-14

    Effective radioprotection for human space travelers hinges upon understanding the individual properties of charged particles. A significant fraction of particle radiation astronauts will encounter in space exploratory missions will come from high energy protons in galactic cosmic radiation (GCR) and/or possible exposures to lower energy proton flux from solar particle events (SPEs). These potential exposures present major concerns for NASA and others, in planning and executing long term space exploratory missions. We recently reported cell survival and transformation (acquisition of anchorage-independent growth in soft agar) frequencies in apparently normal NFF-28 primary human fibroblasts exposed to 0-30 cGy of 50MeV, 100MeV (SPE-like), or 1000 MeV (GCR-like) monoenergetic protons. These were modeled after 1989 SPE energies at an SPE-like low dose-rate (LDR) of 1.65 cGy/min or high dose rate (HDR) of 33.3 cGy/min delivered at the NASA Space Radiation Laboratory (NSRL) at BNL.

  20. Late effects of chronic low dose-rate γ-rays irradiation on mice

    International Nuclear Information System (INIS)

    To evaluate late biological effects of chronic low dose-rate radiation, the life-span and pathological changes were evaluated in mice which had been continuously irradiated with gamma-rays for 400 days. Two hundred (100 male and 100 female) specific-pathogen-free (SPF) B6C3F1 mice at six weeks of age were purchased every month. After a 2-week quarantine, they were divided into 4 groups (1 unirradiated control and 3 irradiated). Irradiation was performed using 137Cs gamma-rays at dose-rates of 20 mGy/day, 1 mGy/day and 0.05 mGy/day with accumulated doses equivalent to 8000 mGy, 400 mGy and 20 mGy, respectively. All mice were kept until they died a natural death. Results of the monthly microbiological examinations confirmed that the mice were maintained under SPF-conditions throughout the experimental period. A total of 4000 mice have been admitted into the experiment since it started in February 1996, all of which have received their predetermined doses and have been transferred to the animal room. Data on the 20 mGy/day group of both sexes suggested a shortened life span. The most common lethal neoplasms in pooled data of unirradiated control and irradiated male mice in order of frequency were neoplasms of the lymphohematopoietic system, liver, and lung. In female mice, neoplasms of the lymphohematopoietic system, soft tissue, and endocrine system were common. (author)

  1. OER of californium-252 at low dose rate for growth inhibition in Vicia faba

    International Nuclear Information System (INIS)

    OER of 252Cf, at low dose rate, has been determined for growth inhibition in Vicia faba roots. A new strain ''BelB'' was used; it was found to be more resistant to prolonged anoxia. Two sets of linear 252Cf sources were used (linear activity 0.31 and 0.47 (μg.cm-1)) in somewhat different geometrical arrangements. The (n+γ) 252Cf dose rates at the level of the root tips were 0.11 and 0.13 Gy.h-1 respectively. The relative contribution of the γ component Dsub(γ) to the total absorbed dose Dsub(n+γ) at the level of the root tips was evaluated Dsub(γ)/Dsub(n+γ)=0.35 for the first source-geometry and 0.42 for the second source-geometry. The reference radiation was the γ emission of 192Ir, used in the same geometrical conditions and for similar irradiation times. Irradiations performed in aerobic and anoxic conditions were alternated. OER values of 1.4 +- 0.1 and 1.5 +- 0.1 were observed for the 252Cf emission with the first and second source-geometry respectively. The corresponding OER values for 192Ir were 2.3 +- 0.2 and 2.6 +- 0.1; the derived oxygen gain factors were then equal to 1.6 and 1.7 repectively

  2. Cancer and non-cancer brain and eye effects of chronic low-dose ionizing radiation exposure

    Directory of Open Access Journals (Sweden)

    Picano Eugenio

    2012-04-01

    Full Text Available Abstract Background According to a fundamental law of radiobiology (“Law of Bergonié and Tribondeau”, 1906, the brain is a paradigm of a highly differentiated organ with low mitotic activity, and is thus radio-resistant. This assumption has been challenged by recent evidence discussed in the present review. Results Ionizing radiation is an established environmental cause of brain cancer. Although direct evidence is lacking in contemporary fluoroscopy due to obvious sample size limitation, limited follow-up time and lack of focused research, anecdotal reports of clusters have appeared in the literature, raising the suspicion that brain cancer may be a professional disease of interventional cardiologists. In addition, although terminally differentiated neurons have reduced or mild proliferative capacity, and are therefore not regarded as critical radiation targets, adult neurogenesis occurs in the dentate gyrus of the hippocampus and the olfactory bulb, and is important for mood, learning/memory and normal olfactory function, whose impairment is a recognized early biomarker of neurodegenerative diseases. The head doses involved in radiotherapy are high, usually above 2 Sv, whereas the low-dose range of professional exposure typically involves lifetime cumulative whole-body exposure in the low-dose range of Conclusions At this point, a systematic assessment of brain (cancer and non-cancer effects of chronic low-dose radiation exposure in interventional cardiologists and staff is needed.

  3. The bcl-2, bax gene expression and apoptosis of continuous low-dose-rate irradiation on PC-3 transplanting tumor

    International Nuclear Information System (INIS)

    Objective: The aim of this study was to investigate bcl-2, bax expression and apoptosis of continuous low-dose-rate irradiation on prostate cancer (PC)-3 transplanting tumor. Methods: The expression of bcl-2 and bax associated with apoptosis between experiment and control groups were analyzed using immunohistochemistry at 48, 96 and 192 h after two 125I seed sources implanting model. The correlation between apoptosis and the ratio of bax/bcl-2 was analyzed using Bi-variable linear correlation. SPSS 11.0 was used to analyse the data. Results: The bcl-2 expression in experiment group began to down-regulated significantly after 125I seed irradiation for 48 h as compared with control(t=2.500, P=0.067), though it was not reached to statistical significance. At 96 and 192 h after irradiation, significantly low expression of bcl- 2 were noted (t=4.950, 3.464; P=0.008 and 0.026). In contrast, significantly over expression of bax was noted at 48, 96 and 192 h after 12si irradiation (t=3.334,4.025,5.292;P=0.029, 0.016 and 0.006). The apoptotic index (AI) for PC-3 at 48, 96 and 192 h after 125I irradiation were 22.3%, 21.7% and 30.7%, which was significantly higher than controls when at 96 and 192 h after 125I irradiation (P= 0.016 and 0.036). Moreover, positive correlation was noted between AI and bax/bcl-2 ratio (r=0.784, P= 0.012). Conclusion: Low-dose-rate irradiation could down-regulate the expression of bcl-2, up-regulate the expression of bax and induced PC-3 cells apoptosis. (authors)

  4. Low Dose-Rate Effects on Chromosomal Aberrations in Workers Occupationally Exposed to Ionising Radiation

    International Nuclear Information System (INIS)

    Full text: Occupational exposure to ionising radiation can be assessed by chromosomal aberrations detected in peripheral blood lymphocytes. Blood samples were collected from 47 occupationally exposed individuals (X-ray diagnostic machines and industrial gamma defectoscopy). The chromosomal aberrations were analysed from at least 500 metaphases per person and their frequencies were compared with those obtained from 110 control individuals. It has been noticed the higher frequency of chromosomal aberrations in the exposed group related to the control. The increase was analysed according to the age groups (31-40, 41-50, and 51-60), sex and duration of employment. The higher frequency of dicentrics was not directly correlated with the age or duration of employment in the exposed group. The acentric fragments were encountered with much higher frequency in the exposed group. The chromosomal aberrations induced by low dose-rate in occupationally exposed people revealed the degree of individual sensitivity and the severity of the initial damage depending on the biological-pathological conditions. (author)

  5. Lifetime radiation risks from low-dose rate radionuclides in beagles

    International Nuclear Information System (INIS)

    One of the largest, long-term (25-yr) animal studies on the effects of low-dose internal irradiation is almost completed. Some 335 beagles were given continuous exposure to graded 90Sr [low linear energy transfer (LET)] in their diets (D-dogs) through adulthood. A second group (R-dogs) was given fractionated doses of 225Ra (high LET) as young adults. A third group of 44 was given a single injection of 90Sr as adults (S-dogs) to compare single to continuous dosages. All dogs were followed through their lifetimes. Only one of the 848 dogs is still alive. The animals were whole-body counted over their entire life span and were examined frequently for assessment of medical status. There were no acute radiation lethalities. Analyses of the large data base from these dogs have begun and preliminary indications are that 90Sr, which was tested over a 1500-fold skeletal dose rate range, does not cause significant life shortening at average accumulation skeletal doses of ∼2500 rads (25 Gy) and that a curvilinear dose response curve for life shortening was seen at higher accumulation doses. The data will be discussed in terms of modern epidemiological concepts and quantifications will be related to certain parameters of human risk from acute or chronic radiation exposures

  6. Preparation and determination of kerma for Iridium 192 sources of low dose rate for brachytherapy

    International Nuclear Information System (INIS)

    The practice of Brachytherapy with Iridium-192 sources of low dose rate (0.4 - 0.8 Gy/h) is a technique used in the treatment of diverse illnesses. in this work the preparation, quality control and calibration are presented in terms of kerma in air of Iridium-192 using as target these recycled Iridium-Platinum wires. The targets were obtained as decayed sources of different radio therapeutical centers in the country and they were characterized by Scanning electron microscopy in order to determine their chemical composition. Subsequently it was developed an experimental design to establish the effect of neutron flux, geometrical array and irradiation time over the activity and percentage of the sources homogeneity. The homogeneity was determined by auto radiography and by Gamma spectroscopy. Once the optimal irradiation conditions were established, it is determined the apparent activity and kerma in air using a well type ionization chamber with traceability to a primary laboratory. Iridium-192 sources were obtained with an average homogeneity 96 %, apparent activity 282.129 ± 0.531 M Bq and kerma in air 0.03200 ± 0.00006 m Gy m/h A. (Author)

  7. Effects of orientation of substrate on the enhanced low-dose-rate sensitivity (ELDRS) in NPN transistors

    Institute of Scientific and Technical Information of China (English)

    LU Wu; ZHENG Yu-Zhan; WANG Yi-Yuan; REN Di-Yuan; GUO Qi; WANG Zhi-Kuan; WANG Jian-An

    2011-01-01

    The radiation effects and annealing characteristics of two types of domestic NPN bipolar junction transistors, fabricated with different orientations, were investigated under different dose-rate irradiation. The experimental results show that both types of the NPN transistors exhibit remarkable Enhanced Low-Dose-Rate Sensitivity (ELDRS). After irradiation at high or low dose rate, the excess base current of NPN transistors obviously increased, and the current gain would degrade rapidly. Moreover, the decrease of collector current was also observed. The NPN transistor with (111) orientation was more sensitive to ionizing radiation than that with (100) orientation. The underlying mechanisms of various experimental phenomena are discussed in detail in this paper.

  8. Effects of orientation of substrate on the enhanced low-dose-rate sensitivity (ELDRS) in NPN transistors

    Science.gov (United States)

    Lu, Wu; Zheng, Yu-Zhan; Wang, Yi-Yuan; Ren, Di-Yuan; Guo, Qi; Wang, Zhi-Kuan; Wang, Jian-An

    2011-02-01

    The radiation effects and annealing characteristics of two types of domestic NPN bipolar junction transistors, fabricated with different orientations, were investigated under different dose-rate irradiation. The experimental results show that both types of the NPN transistors exhibit remarkable Enhanced Low-Dose-Rate Sensitivity (ELDRS). After irradiation at high or low dose rate, the excess base current of NPN transistors obviously increased, and the current gain would degrade rapidly. Moreover, the decrease of collector current was also observed. The NPN transistor with orientation was more sensitive to ionizing radiation than that with orientation. The underlying mechanisms of various experimental phenomena are discussed in detail in this paper.

  9. [Phantom Study on Dose Reduction Using Iterative Reconstruction in Low-dose Computed Tomography for Lung Cancer Screening].

    Science.gov (United States)

    Minehiro, Kaori; Takata, Tadanori; Hayashi, Hiroyuki; Sakuda, Keita; Nunome, Haruka; Kawashima, Hiroko; Sanada, Shigeru

    2015-12-01

    We investigated dose reduction ability of an iterative reconstruction technology for low-dose computed tomography (CT) for lung cancer screening. The Sinogram Affirmed Iterative Reconstruction (SAFIRE) provided in a multi slice CT system, Somatom Definition Flash (Siemens Healthcare) was used. An anthropomorphic chest phantom (N-1, Kyoto Kagaku) was scanned at volume CT dose index (CTDIvol) of 0.50-11.86 mGy with 120 kV. For noise (standard deviation) and contrast-to-noise ratio (CNR) measurements, CTP486 and CTP515 modules in the Catphan (The Phantom Laboratory) were scanned. Radiological technologists were participated in the perceptual comparison. SAFIRE reduced the SD values by approximately 50% compared with filter back projection (FBP). The estimated dose reduction rates by SAFIRE determined from the perceptual comparison was approximately 23%, while 75% dose reduction rate was expected from the SD value reduction of 50%. PMID:26685831

  10. Low dose rate caesium-137 implant time of intracavitary brachytherapy source of a selected oncology center in Ghana

    Directory of Open Access Journals (Sweden)

    John Owusu Banahene

    2015-01-01

    Full Text Available Background: The treatment time taken for a radioactive source is found to be very important in intracavitary brachytherapy treatment. The duration of the treatment time depends on the prescribed dose requested to a reference point and the calculated dose rate to the same point. The duration of the treatment time of source is found to depend on the tumour stage. In this work, the treatment time of implant has been calculated for a Caesium-137 low dose rate brachytherapy source at an oncology facility in Ghana. Objective: The objective was to determine how the treatment time of tumours depends on the dose rate to the reference point prescribed by the Oncologists and the dose rate determined by the dosimetrists at the facility. Materials and Method: Depending upon the stage of the cancer, the Oncologist determines the type of treatment modality, source configuration for the cancer patient and positions of both tandem and ovoids in the cervix. Depending also on the tumour stage, two orthogonal radiographic X-ray films are taken using a simulator machine. The treatment machine used in the study is AMRA-Curietron. The maximum activity of the source was 259GBq. It has five channels which is a manual remote afterloader. In clinical practice, the treatment time t is very short(only some few days for such low dose rate brachytherapy source like Cs-137 which lasts only for some few days in comparison with the half life of the Cs-137 source. The mathematical equation for the calculation of treatment time is written as t=D/D. Hence t is the treatment time of the radioactive source of patients undergoing intracavitary brachytherapy treatment, D is prescribed dose to a reference point and D is the dose rate to the same reference point. Results: The calculated treatment time of the Cs-137 brachytherapy source for different source arrangements or channels used in clinical practice at the brachytherapy Centre have been determined. Also provided, are the

  11. Patient Perspectives on Low-Dose Computed Tomography for Lung Cancer Screening, New Mexico, 2014

    Science.gov (United States)

    Sussman, Andrew L.; Murrietta, Ambroshia M.; Getrich, Christina M.; Rhyne, Robert; Crowell, Richard E.; Taylor, Kathryn L.; Reifler, Ellen J.; Wescott, Pamela H.; Saeed, Ali I.; Hoffman, Richard M.

    2016-01-01

    Introduction National guidelines call for annual lung cancer screening for high-risk smokers using low-dose computed tomography (LDCT). The objective of our study was to characterize patient knowledge and attitudes about lung cancer screening, smoking cessation, and shared decision making by patient and health care provider. Methods We conducted semistructured qualitative interviews with patients with histories of heavy smoking who received care at a Federally Qualified Health Center (FQHC Clinic) and at a comprehensive cancer center-affiliated chest clinic (Chest Clinic) in Albuquerque, New Mexico. The interviews, conducted from February through September 2014, focused on perceptions about health screening, knowledge and attitudes about LDCT screening, and preferences regarding decision aids. We used a systematic iterative analytic process to identify preliminary and emergent themes and to create a coding structure. Results We reached thematic saturation after 22 interviews (10 at the FQHC Clinic, 12 at the Chest Clinic). Most patients were unaware of LDCT screening for lung cancer but were receptive to the test. Some smokers said they would consider quitting smoking if their screening result were positive. Concerns regarding screening were cost, radiation exposure, and transportation issues. To support decision making, most patients said they preferred one-on-one discussions with a provider. They also valued decision support tools (print materials, videos), but raised concerns about readability and Internet access. Conclusion Implementing lung cancer screening in sociodemographically diverse populations poses significant challenges. The value of tobacco cessation counseling cannot be overemphasized. Effective interventions for shared decision making to undergo lung cancer screening will need the active engagement of health care providers and will require the use of accessible decision aids designed for people with low health literacy. PMID:27536900

  12. Palliative low dose fortnightly methotrexate in oral cancers: Experience at a rural cancer centre from India

    Directory of Open Access Journals (Sweden)

    Santam Chakraborty

    2014-01-01

    Full Text Available Context: Palliative fortnightly chemotherapy in oral cancers. Aims: We present our experience with a regimen employing fortnightly (once in 2 weeks injectable methotrexate (MTX (40 mg/m 2 in a predominantly elderly cohort of patients with carcinoma of oral cavity and oropharynx. Settings and Design: Retrospective chart review conducted at a rural cancer center in India. Materials and Methods: All patients with oral cavity and oropharyngeal cancers started on treatment with fortnightly injectable MTX (40 mg/m 2 between 01/01/2011 and 31/12/2011. Statistical Analysis Used: The factors analyzed included the duration of disease control, pain control, overall survival and progression free survival which were evaluated using the Kaplan Meier method. Results: A total of 60 patients with a median age of 66.5 years were analyzed. Majority of the patients had poor nutritional status, performance status or co-morbidities. MTX was given for recurrent disease in 19 patients and after initial palliative radiotherapy in 41 patients. The median number of cycles delivered was nine. Grade 3/4 toxicities were seen in 2 patients only. Disease control rate at the end of treatment was seen in 33 (55% patients. Median overall survival was 34 weeks (interquartile range: 17-50 weeks. Conclusions: The fortnightly regimen of MTX was well-tolerated and showed a good clinical activity in this elderly cohort of patients with advanced oral cavity and oropharyngeal cancers.

  13. Late effects of chronic low dose-rate γ-rays irradiation on mice

    International Nuclear Information System (INIS)

    To evaluate late biological effects of chronic low dose-rate radiation, the life-span and pathological changes were evaluated in mice that were continuously irradiated with gamma-rays for 400 days. Two hundred (100 male and 100 female) specific-pathogen-free (SPF) B6C3F1 mice at six weeks of age were purchased every month. After a 2-week quarantine, they were divided into 4 groups (1 unirradiated control and 3 irradiated). Irradiation was performed using 137Cs gamma-rays at dose-rates of 20 mGy (22 h-day)-1, 1 mGy (22 h-day)-1 and 0.05 mGy (22 h-day)''-1 with accumulated doses equivalent to 8,000 mGy, 400 mGy and 20 mGy, respectively. All mice were kept until they died a natural death. Results of the monthly microbiological examinations confirmed that the mice were maintained under SPF-conditions throughout the experimental period. A total of 4,000 mice have been admitted into the experiment since it started in February 1996, all of which have received their predetermined doses and have been transferred to the animal room. Data on the 20 mGy (22 h-day)-1 group of both sexes suggested a shortened life span. The most common lethal neoplasms in pooled data of unirradiated control male mice and irradiated male mice in order of frequency were neoplasms of the lymphohematopoietic system, liver, lung, and soft tissue. In female mice, neoplasms of the lymphohematopoietic system, soft tissue, endocrine system, and liver were most common. (author)

  14. A brief measure of Smokers' knowledge of lung cancer screening with low-dose computed tomography.

    Science.gov (United States)

    Lowenstein, Lisa M; Richards, Vincent F; Leal, Viola B; Housten, Ashley J; Bevers, Therese B; Cantor, Scott B; Cinciripini, Paul M; Cofta-Woerpel, Ludmila M; Escoto, Kamisha H; Godoy, Myrna C B; Linder, Suzanne K; Munden, Reginald F; Volk, Robert J

    2016-12-01

    We describe the development and psychometric properties of a new, brief measure of smokers' knowledge of lung cancer screening with low-dose computed tomography (LDCT). Content experts identified key facts smokers should know in making an informed decision about lung cancer screening. Sample questions were drafted and iteratively refined based on feedback from content experts and cognitive testing with ten smokers. The resulting 16-item knowledge measure was completed by 108 heavy smokers in Houston, Texas, recruited from 12/2014 to 09/2015. Item difficulty, item discrimination, internal consistency and test-retest reliability were assessed. Group differences based upon education levels and smoking history were explored. Several items were dropped due to ceiling effects or overlapping constructs, resulting in a 12-item knowledge measure. Additional items with high item uncertainty were retained because of their importance in informed decision making about lung cancer screening. Internal consistency reliability of the final scale was acceptable (KR-20 = 0.66) and test-retest reliability of the overall scale was 0.84 (intraclass correlation). Knowledge scores differed across education levels (F = 3.36, p = 0.04), while no differences were observed between current and former smokers (F = 1.43, p = 0.24) or among participants who met or did not meet the 30-pack-year screening eligibility criterion (F = 0.57, p = 0.45). The new measure provides a brief, valid and reliable indicator of smokers' knowledge of key concepts central to making an informed decision about lung cancer screening with LDCT, and can be part of a broader assessment of the quality of smokers' decision making about lung cancer screening. PMID:27512650

  15. Long-term prognosis of patients with lung cancer detected on low-dose chest computed tomography screening.

    Science.gov (United States)

    Nawa, Takeshi; Nakagawa, Tohru; Mizoue, Tetsuya; Kusano, Suzushi; Chonan, Tatsuya; Fukai, Shimao; Endo, Katsuyuki

    2012-02-01

    The effectiveness of lung cancer screening using low-dose chest computed tomography (CT) remains elusive. The present study examined the prognosis of patients with lung cancer detected on CT screening in Japanese men and women. Subjects were 210 patients with primary lung cancer identified on CT screening at two medical facilities in Hitachi, Japan, where a total of 61,914 CT screenings were performed among 25,385 screenees between 1998 and 2006. Prognostic status of these patients was sought by examining medical records at local hospitals, supplemented by vital status information from local government. The 5-year survival rate was estimated according to the characteristics of patients and lung nodule. A total of 203 (97%) patients underwent surgery. During a 5.7-year mean follow-up period, 19 patients died from lung cancer and 6 died from other causes. The estimated 5-year survival rate for all patients and for those on stage IA was 90% and 97%, respectively. Besides cancer stage, smoking and nodule appearance were independent predictors of a poor survival; multivariable-adjusted hazard ratio (95% confidence interval) was 4.7 (1.3, 16.5) for current and past smokers versus nonsmokers and 4.6 (1.6, 13.9) for solid nodule versus others. Even patients with solid shadow had a 5-year survival of 82% if the lesion was 20mm or less in size. Results suggest that lung cancers detected on CT screening are mostly curative. The impact of CT screening on mortality at community level needs to be clarified by monitoring lung cancer deaths.

  16. COMPROMISING EFFECT OF LOW DOSE-RATE TOTAL-BODY IRRADIATION ON ALLOGENEIC BONE-MARROW ENGRAFTMENT

    NARCIS (Netherlands)

    VANOS, R; KONINGS, AWT; DOWN, JD

    1993-01-01

    The protraction of total body irradiation (TBI) to a continuous low dose-rate has been investigated for its effect on donor marrow engraftment in murine bone marrow transplant (BMT) models of varying histocompatibility. Three different BMT combinations were used: syngeneic [B6-Gpi-1a --> B6-Gpi-1b],

  17. Injury to the blood-testis barrier after low-dose-rate chronic radiation exposure in mice

    International Nuclear Information System (INIS)

    Exposure to ionising radiation induces male infertility, accompanied by increasing permeability of the blood-testis barrier. However, the effect on male fertility by low-dose-rate chronic radiation has not been investigated. In this study, the effects of low-dose-rate chronic radiation on male mice were investigated by measuring the levels of tight-junction-associated proteins (ZO-1 and occludin-1), Niemann-Pick disease type 2 protein (NPC-2) and anti-sperm antibody (AsAb) in serum. BALB/c mice were exposed to low-dose-rate radiation (3.49 mGy h-1) for total exposures of 0.02 (6 h), 0.17 (2 d) and 1.7 Gy (21 d). Based on histological examination, the diameter and epithelial depth of seminiferous tubules were significantly decreased in 1.7-Gy-irradiated mice. Compared with those of the non-irradiated group, 1.7-Gy-irradiated mice showed significantly decreased ZO-1, occludin-1 and NPC-2 protein levels, accompanied with increased serum AsAb levels. These results suggest potential blood-testis barrier injury and immune infertility in male mice exposed to low-dose-rate chronic radiation. (authors)

  18. Chloroquine Improves Survival and Hematopoietic Recovery After Lethal Low-Dose-Rate Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lim Yiting [Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Hedayati, Mohammad; Merchant, Akil A.; Zhang Yonggang; Yu, Hsiang-Hsuan M. [Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Kastan, Michael B. [Department of Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina (United States); Matsui, William, E-mail: matsuwi@jhmi.edu [Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); DeWeese, Theodore L., E-mail: deweete@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States)

    2012-11-01

    Purpose: We have previously shown that the antimalarial agent chloroquine can abrogate the lethal cellular effects of low-dose-rate (LDR) radiation in vitro, most likely by activating the ataxia-telangiectasia mutated (ATM) protein. Here, we demonstrate that chloroquine treatment also protects against lethal doses of LDR radiation in vivo. Methods and Materials: C57BL/6 mice were irradiated with a total of 12.8 Gy delivered at 9.4 cGy/hour. ATM null mice from the same background were used to determine the influence of ATM. Chloroquine was administered by two intraperitoneal injections of 59.4 {mu}g per 17 g of body weight, 24 hours and 4 hours before irradiation. Bone marrow cells isolated from tibia, fibula, and vertebral bones were transplanted into lethally irradiated CD45 congenic recipient mice by retroorbital injection. Chimerism was assessed by flow cytometry. In vitro methylcellulose colony-forming assay of whole bone marrow cells and fluorescence activated cell sorting analysis of lineage depleted cells were used to assess the effect of chloroquine on progenitor cells. Results: Mice pretreated with chloroquine before radiation exhibited a significantly higher survival rate than did mice treated with radiation alone (80% vs. 31%, p = 0.0026). Chloroquine administration before radiation did not affect the survival of ATM null mice (p = 0.86). Chloroquine also had a significant effect on the early engraftment of bone marrow cells from the irradiated donor mice 6 weeks after transplantation (4.2% vs. 0.4%, p = 0.015). Conclusion: Chloroquine administration before radiation had a significant effect on the survival of normal but not ATM null mice, strongly suggesting that the in vivo effect, like the in vitro effect, is also ATM dependent. Chloroquine improved the early engraftment of bone marrow cells from LDR-irradiated mice, presumably by protecting the progenitor cells from radiation injury. Chloroquine thus could serve as a very useful drug for protection

  19. DNA damage-centered signaling pathways are effectively activated during low dose-rate Auger radioimmunotherapy

    International Nuclear Information System (INIS)

    Introduction: Low dose-rate radioimmunotherapy (RIT) using 125I-labelled monoclonal antibodies (125I-mAbs) is associated with unexpected high cytotoxicity per Gy. Methods: We investigated whether this hypersensitivity was due to lack of detection of DNA damage by the targeted cells. DNA damage was measured with the alkaline comet assay, gamma-H2AX foci and the micronucleus test in p53−/− and p53+/+ HCT116 cells exposed to increasing activities of internalizing anti-HER1 125I-mAbs or non-internalizing anti-CEA 125I-mAbs. The expression of proteins involved in radiation response and progression of cells through the cycle were determined. Results: Cell hypersensitivity to low absorbed doses of anti-CEA 125I-mAbs was not due to defect in DNA damage detection, since ATM (ataxia telangiectasia mutated gene), gamma-H2AX, p53 and p21 were activated in RIT-treated HCT116 cells and G2/M cell cycle arrest was observed. Moreover, the alkaline comet assay showed that DNA breaks accumulated when cells were placed at 4 °C during exposure but were repaired under standard RIT conditions (37 °C), suggesting that lesions detected under alkaline conditions (mostly DNA single strand breaks and alkali-labile sites) are efficiently repaired in treated cells. The level of gamma-H2AX protein corroborated by the level of foci measured in nuclei of treated cells was shown to accumulate with time thereby suggesting the continuous presence of DNA double strand breaks. This was accompanied by the formation of micronuclei. Conclusion: Hypersensitivity to non-internalizing 125I-mAbs is not due to lack of detection of DNA damage after low absorbed dose-rates. However, DNA double strand breaks accumulate in cells exposed both to internalizing and non-internalizing 125I-mAbs and lead to micronuclei formation. These results suggest impairment in DNA double strand breaks repair after low absorbed doses of 125I-mAbs

  20. Contamination and cancers: low-dose risks and standards of radioprotection

    International Nuclear Information System (INIS)

    Irradiation of the population due to the running of nuclear power stations represents less than 1% of the natural radioactivity today, and should amount to 3% at most by the year 2 000. The main effects of ionizing radiations are reviewed and their undetectability below 100 rems is underlined. Thus the evaluation of low-dose risks can only be speculative and the cautions hypothesis adopted is that of a linear relationship between dose and effect, together with the absence of threshold. According to calculations the worker, supposedly exposed to 500 mrem a year between ages 18 and 65, would run a 22.2% instead of the normal 22% risk of dying of cancer. As for the population, the risk would increase by only 1 per 10 000 in the year 2 000. This means that no other mutagenic and carcinogenic agent is as well regulated as radioactive pollution and efforts directed at a better control of harmful chemicals, for instance, are only taking an example from the ruling on radioprotection

  1. Expression of Genes Associated with DNA Damage Sensing in Human Fibroblasts Exposed to Low-dose-rate Gamma Rays

    Science.gov (United States)

    Zhang, Ye; Mehta, Satish; Hammond, Diane; Pierson, Duane; Jeevarajan, Antony; Cucinotta, Francis; Rohde, Larry; Wu, Honglu

    2007-01-01

    Understanding of the molecular response to low-dose and low-dose-rate radiation exposure is essential for the extrapolation of high-dose radiation risks to those at dose levels relevant to space and other environmental concerns. Most of the reported studies of gene expressions induced by low-dose or low-dose-rate radiation were carried out on exponentially growing cells. In the present study, we analyzed expressions of 84 genes associated with DNA damage sensing using real time PCR in human fibroblasts in mostly G1 phase of the cell cycle. The cells were exposed continuously to gamma rays at a dose rate of 0.8 cGy/hr for 1, 2, 6 or 24 hrs at 37 C throughout the exposure. The total RNA was isolated immediately after the exposure was terminated. Of the 84 genes, only a few showed significant changes of the expression level. Some of the genes (e.g. DDit3 and BTG2) were found to be up or down regulated only after a short period of exposure, while other genes (e.g. PRKDC) displayed a highest expression level at the 24 hr time point. The expression profiles for the exposed cells which had a smaller portion of G1 cells indicated more cell cycle signaling and DNA repair genes either up or down regulated. Interestingly, the panel of genes changed from radiation exposure in G1 cells is different from the panel in cells having less G1 arrest cells. The gene expression profile of the cells responding to low-dose-radiation insult apparently depends on the cell growth stage. The response pathway in G1 cells may differ from that in exponentially growing cells.

  2. Chemo-endocrine therapy with low-dose cisplatin, UFT, and dexamethasone for hormone-refractory prostate cancer patients

    International Nuclear Information System (INIS)

    Since September 2005, twenty-two patients with hormone-refractory prostate cancer (aged 55-81 years) were treated with LH-RH agonist and low-dose cisplatin, tegafur-uracil (UFT), and dexamethasone after proving resistant to estramustine phosphate therapy. The regimen of this therapy consists of 5 mg/body of cisplatin intravenously once a week, 300 mg/day of UFT and 1 mg/day of dexamethasone orally, every day. All patients suffered from clinical progression such as local recurrence in 11 patients who had already received radiation therapy, lymph node metastasis in 7 patients, and bone metastasis in 15 patients. Initial prostate specific antigen (PSA) value ranged from 1.7 ng/mL to 215.1 ng/mL. The PSA response rate, which decreased more than 50% in PSA values was 72.7% (16/22). The follow-up term ranged from 2 to 43 months, and nine patients died of cancer progression. The median time to progression was 11 months, and median overall survival was 19 months. There were no severe adverse effects, and stoppages of the therapy for 13 patients were all due to disease progression. Following this therapy, 9 patients received best supportive care and 4 patients received docetaxel chemotherapy. We considered this therapy to be effective for patients with hormone-refractory prostate cancer because it maintained their good quality of life (QOL). (author)

  3. Estimation of non-cancer stochastic effects of prolonged occupational exposure in low dose range

    International Nuclear Information System (INIS)

    This study is aimed at estimation of acute myocardial infarction (AMI) incidence and risk among persons exposed to prolonged low dose rate ionizing radiation. Prevalence and social and medical relevance, and available data on the increased cardio-vascular diseases mortality among nuclear workers determined the chosen clinical model (Howe G.R.,et. Al., 2004). A study was carried out into AMI incidence in closed population of Seversk in 1998-2004, the study was supported by the Federal Agency for Science and Innovations (grant MK-4931.2007.7). Siberian Group of Chemical Enterprises (SGCE) is a town-forming enterprise. Because of this the whole population was divided into residents and SGCE workers, of whom great majority was exposed to long term ionizing radiation in low doses (total cumulative external dose was up to 1 Sv). In the study period, increased incidence was found in both groups (from 5.12 up to 7.11 per 1 000 workers, and from 1.86 up to 2.44 per 1 000 residents). Cross-group analysis (SGCE workers - residents) revealed that general AMI incidence in SGCE employees was significantly greater (χ2 = 64.44-89.05-86.22-65.17-39.78-114.89-96.14; r 2 = 3.54-3.97-3.27-4.59-0.59-18.19-17.58; r = 0.0601-0.0462-0.0706-0.0322-0.4443-0.0000-0.0000 in 1998-2004 respectively). Analysis of standardized relative risk coefficients of developing AMI demonstrated their significant increase in the main group production (auxiliary production incidence was taken as the standard): 1.5 in 1999 (CI 95% 1.15-2.79), 1.8 in 2000 (CI 95% 1.07-2.47), 2.0 in 2001 (CI 95% 1.31-2.99), 2.1 in 2003 (CI 95% 1.42-3.11), 1.9 in 2004 (CI 95% 1.27-2.89). At present, there is data indicating close relationship between AMI development and dose accumulation rate; however, because of irradiation dose homogeneity of the study groups (great majority of AMI patients had doses up to 200 mSv) and limited number of cases in the sample, it was not possible to establish association between AMI development

  4. Impacts of low dose rate irradiation on the fertility, fecundity and hatchling survival of Japanese rice fish (medaka, Oryzias latipes)

    International Nuclear Information System (INIS)

    A renewed international interest in the effects on biota from low dose rate irradiation has recently occurred. Much of that interest is centered on the relevance of previously accepted dose rate guidelines (e.g. 10 mGy d-1 for aquatic biota) suggested by the ICRP and IAEA. All parties concerned seem to agree that additional data are needed on population level impacts from chronic low-level exposures to radionuclides. Using a Low Dose Rate Irradiation Facility (LoDIF), we conducted an experiment on the fecundity, fertility and hatchling survival of Japanese Rice Fish (medaka, Oryzias latipes). Fish were exposed externally to 137Cs from juvenile through adulthood at mean dose rates of 3.5, 35 and 350 mGy d-1. Fish were bred at maturity and the following endpoints were examined: 1) the number of eggs produced; 2) the percent of eggs that hatched; and 3) the survival of hatchlings 20-days post hatch. The influence of gender was examined by breeding irradiated males with control females; control males with irradiated females; irradiated males with irradiated females; and control males with control females. The data contribute to our understanding the impacts of low dose rate irradiation. (author)

  5. Phase II Study of Chemoradiotherapy With S-1 and Low-Dose Cisplatin for Inoperable Advanced Gastric Cancer

    International Nuclear Information System (INIS)

    Purpose: The results of a pilot study using S-1/low-dose cisplatin/radiotherapy led us to hypothesize that the initial chemoradiotherapy regimen would induce a 70% efficacy rate with a 10% pathologic complete response rate. Patients and Methods: Only patients with unresectable or incurable advanced gastric cancer were eligible. The patients received induction S-1 and cisplatin therapy with radiotherapy followed by chemotherapy alone. Results: Of the 30 patients recruited and assessed, 29 were eligible for clinical evaluation of measurable lesions. The response rate was 65.5%, with 19 with a partial response, 8 with no change, and 2 with progressive disease of 29 patients. Of the 30 patients recruited, 10 (33.3%) underwent stomach resection and D2 LN dissections. The pathologic complete response rate was 13.3% (4 patients), and the R0 resection rate was 100% (10 patients). The survival analysis showed a median survival time of 25 months. Grade 3 toxicity occurred in 66.7% for leukocytopenia, 33.3% for thrombocytopenia, 23.3% for nausea and appetite loss, and 6.7% for anemia, diarrhea, and renal dysfunction. Although all the patients had been hospitalized with a poor performance status with a giant tumor, 97% (29 of 30) could be discharged after the first cycle, resulting in an improvement in quality of life. Conclusion: Chemoradiotherapy could be a powerful regimen for controlling tumor progression in advanced gastric cancer, improving patients' quality of life with tolerable toxicity. A complete histologic response rate of >10% would be expected, even for large tumors with metastatic lesions

  6. Chronic low-dose-rate ionising radiation affects the hippocampal phosphoproteome in the ApoE−/− Alzheimer mouse model

    DEFF Research Database (Denmark)

    Kempf, Stefan; Janik, Dirk; Barjaktarovic, Zarko;

    2016-01-01

    Accruing data indicate that radiation-induced consequences resemble pathologies of neurodegenerative diseases such as Alzheimer´s. The aim of this study was to elucidate the effect on hippocampus of chronic low-dose-rate radiation exposure (1 mGy/day or 20 mGy/day) given over 300 days with cumula......Accruing data indicate that radiation-induced consequences resemble pathologies of neurodegenerative diseases such as Alzheimer´s. The aim of this study was to elucidate the effect on hippocampus of chronic low-dose-rate radiation exposure (1 mGy/day or 20 mGy/day) given over 300 days...... with cumulative doses of 0.3 Gy and 6.0 Gy, respectively. ApoE deficient mutant C57Bl/6 mouse was used as an Alzheimer´s model. Using mass spectrometry, a marked alteration in the phosphoproteome was found at both dose rates. The radiation-induced changes in the phosphoproteome were associated with the control...... that several molecular targets induced by chronic low-dose-rate radiation overlap with those of Alzheimer´s pathology. It may suggest that ionising radiation functions as a contributing risk factor to this neurodegenerative disease....

  7. Low dose reirradiation in combination with hyperthermia: a palliative treatment for patients with breast cancer recurring in previously irradiated areas.

    Science.gov (United States)

    van der Zee, J; Treurniet-Donker, A D; The, S K; Helle, P A; Seldenrath, J J; Meerwaldt, J H; Wijnmaalen, A J; van den Berg, A P; van Rhoon, G C; Broekmeyer-Reurink, M P

    1988-12-01

    Ninety-seven patients with breast cancer recurring in a previously irradiated area (mean dose 44 Gy) were reirradiated in combination with hyperthermia and had evaluable tumor responses. In the reirradiation series, radiotherapy was given twice weekly in most patients, with a fraction size varying from 200 to 400 cGy, the total dose varying from 8 to 32 Gy. Hyperthermia was given following the radiotherapy fractions. The combined treatment resulted in 35% complete and 55% partial responses. Duration of response was median 4 months for partial response and 26 months for complete response, respectively. The median survival time for all patients was 12 months. Acute skin reaction was mild, with more than moderate erythema in only 14/97 patients. Thermal burns occurred in 44/97 patients, generally at sites where pain sensation was decreased, and therefore they did not cause much inconvenience. In the 19 patients who survived more than 2 years, no late radiation damage was observed. When patients who received a "high dose" (greater than 29 Gy and hyperthermia) were compared with those who received a "low dose" (less than 29 Gy and hyperthermia), a higher complete response rate was observed in the high dose group (58% vs. 24%), whereas no difference in acute toxicity was found. We conclude that reirradiation with 8 x 4 Gy in combination with hyperthermia twice weekly is a safe, effective and well tolerated method for palliative treatment of patients with breast cancer recurring in previously irradiated areas.

  8. Dose-rate effects and chronological changes of chromosome aberration rates in spleen cells from mice that are chronically exposed to gamma-ray at low dose rates

    International Nuclear Information System (INIS)

    Dose-rate effects have not been examined in the low dose-rate regions of less than 60-600 mGy/h. Mice were chronically exposed to gamma-ray at 20 mGy/day (approximately 1 mGy/h) up to 700 days and at 1 mGy/day (approximately 0.05 mGy/h) for 500 days under SPF conditions. Chronological changes of chromosome aberration rates in spleen cells were observed along with accumulated doses at both low dose-rates. Unstable aberrations increased in a biphasic manner within 0-2 Gy and 4-14 Gy in 20 mGy/day irradiation. They slightly increased up to 0.5 Gy in 1 mGy/day irradiation. Chromosome aberration rates at 20 mGy/day and 1 mGy/day were compared at the same total doses of 0.5 Gy and 0.25 Gy. They were 2.0 vs. 0.53, and 1.0 vs. 0.47 respectively. Thus, dose-rate effects were observed in these low dose-rate regions. (author)

  9. Low Dose Effects: Testing the Assumptions

    International Nuclear Information System (INIS)

    Our work is to investigate the biological responses of cells and animals to low doses and low dose rates of low linear energy transfer radiation and to compare the results to the predictions of the Linear No-Threshold (LNT) hypothesis. These experiments indicate that at low dose, none of the assumptions of the LNT hypothesis were supported by the data, either in cells or in animals. If these results from human and rodent cells, and from other animals, are applicable to humans, the data further indicate that the use of the LNT hypothesis for radiation protection purposes is not conservative but may actually increase the overall risk of cancer

  10. Assessment of I-125 seed implant accuracy when using the live-planning technique for low dose rate prostate brachytherapy

    International Nuclear Information System (INIS)

    Low risk prostate cancers are commonly treated with low dose rate (LDR) brachytherapy involving I-125 seeds. The implementation of a ‘live-planning’ technique at the Royal Adelaide Hospital (RAH) in 2007 enabled the completion of the whole procedure (i.e. scanning, planning and implant) in one sitting. ‘Live-planning’ has the advantage of a more reliable delivery of the planned treatment compared to the ‘traditional pre-plan’ technique (where patient is scanned and planned in the weeks prior to implant). During live planning, the actual implanted needle positions are updated real-time on the treatment planning system and the dosimetry is automatically recalculated. The aim of this investigation was to assess the differences and clinical relevance between the planned dosimetry and the updated real-time implant dosimetry. A number of 162 patients were included in this dosimetric study. A paired t-test was performed on the D90, V100, V150 and V200 target parameters and the differences between the planned and implanted dose distributions were analysed. Similarly, dosimetric differences for the organs at risk (OAR) were also evaluated. Small differences between the primary dosimetric parameters for the target were found. Still, the incidence of hotspots was increased with approximately 20% for V200. Statistically significant increases were observed in the doses delivered to the OAR between the planned and implanted data; however, these increases were consistently below 3% thus probably without clinical consequences. The current study assessed the accuracy of prostate implants with I-125 seeds when compared to initial plans. The results confirmed the precision of the implant technique which RAH has in place. Nevertheless, geographical misses, anatomical restrictions and needle displacements during implant can have repercussions for centres without live-planning option if dosimetric changes are not taken into consideration

  11. Health effects of prolonged low-dose rate gamma-irradiation of a human population in Taiwan, 1983-2003

    Energy Technology Data Exchange (ETDEWEB)

    Chang, W. P.; Hsieh, W. A.; Lin, Y. P.; Huang, S.; Hwang, B. F.; Lee, S. D.; Chen, J. C.; Tsai, M.; Yen, N. P.

    2004-07-01

    Health effects of low dose-rate , low LET irradiation on large numbers of human population have been rare and less well known and studied. However, the standards for safety and health regulation for radiation exposure depend on solid observations of related studies. during 1983 to mid 1990s, an unusual contamination occurred that was derived from several lost Co-60 orphan sources and un-intentionally recycled into thousands tons construction steels, eventually employed for construction in several cities in Taiwan. Continuous studies on the immediate and prolonged health effects of these 7,000 subjects, with more than 60% have been exposed during prenatal, childhood, and adolescents periods, have been able to form a stron scientific avenue to provide evidences for unusual observation on a human population in natural environments. Moreover, an exposure reconstruction program, co-joined with scientists in National Institute of Occupational Safety and Health and Oregan State University in the U. S.; were initiated and continued throughout the study program that critically provided dose response analysis feasible. These studies include bone marrow/hematological changes, lens opacities, thyroid function and thyroid glands abnormalities, growth and development in physical parameters, helper and suppressor T cell populations, serum p53 protein levels, and cancer incidences and risks. Moreover, several cytogenetic markers have been employed to analyze the subtle changes in the somatic tissues. These include frequencies of micronuclei formation, chromosomal aberrations and chromosomal translocations on circulating T-lymphocytes. Functional studies including IQ testing on prenatally exposed children and the reproductive potential as time-to-pregnancy, TTP, were also observed in married couples with offspring. The observations, published in more than 20 manuscripts, will be summarized and presented for future collaborative studies, based on the established database, case

  12. SU-E-T-546: Use of Implant Volume for Quality Assurance of Low Dose Rate Brachytherapy Treatment Plans

    Energy Technology Data Exchange (ETDEWEB)

    Wilkinson, D; Kolar, M [Radiation Oncology, Cleveland Clinic Foundation, Cleveland, OH (United States)

    2014-06-01

    Purpose: To analyze the application of volume implant (V100) data as a method for a global check of low dose rate (LDR) brachytherapy plans. Methods: Treatment plans for 335 consecutive patients undergoing permanent seed implants for prostate cancer and for 113 patients treated with plaque therapy for ocular melanoma were analyzed. Plaques used were 54 COMS (10 to 20 mm, notched and regular) and 59 Eye Physics EP917s with variable loading. Plots of treatment time x implanted activity per unit dose versus v100 ^.667 were made. V100 values were obtained using dose volume histograms calculated by the treatment planning systems (Variseed 8.02 and Plaque Simulator 5.4). Four different physicists were involved in planning the prostate seed cases; two physicists for the eye plaques. Results: Since the time and dose for the prostate cases did not vary, a plot of implanted activity vs V100 ^.667 was made. A linear fit with no intercept had an r{sup 2} = 0.978; more than 94% of the actual activities fell within 5% of the activities calculated from the linear fit. The greatest deviations were in cases where the implant volumes were large (> 100 cc). Both COMS and EP917 plaque linear fits were good (r{sup 2} = .967 and .957); the largest deviations were seen for large volumes. Conclusions: The method outlined here is effective for checking planning consistency and quality assurance of two types of LDR brachytherapy treatment plans (temporary and permanent). A spreadsheet for the calculations enables a quick check of the plan in situations were time is short (e.g. OR-based prostate planning)

  13. SU-E-T-546: Use of Implant Volume for Quality Assurance of Low Dose Rate Brachytherapy Treatment Plans

    International Nuclear Information System (INIS)

    Purpose: To analyze the application of volume implant (V100) data as a method for a global check of low dose rate (LDR) brachytherapy plans. Methods: Treatment plans for 335 consecutive patients undergoing permanent seed implants for prostate cancer and for 113 patients treated with plaque therapy for ocular melanoma were analyzed. Plaques used were 54 COMS (10 to 20 mm, notched and regular) and 59 Eye Physics EP917s with variable loading. Plots of treatment time x implanted activity per unit dose versus v100 ^.667 were made. V100 values were obtained using dose volume histograms calculated by the treatment planning systems (Variseed 8.02 and Plaque Simulator 5.4). Four different physicists were involved in planning the prostate seed cases; two physicists for the eye plaques. Results: Since the time and dose for the prostate cases did not vary, a plot of implanted activity vs V100 ^.667 was made. A linear fit with no intercept had an r2 = 0.978; more than 94% of the actual activities fell within 5% of the activities calculated from the linear fit. The greatest deviations were in cases where the implant volumes were large (> 100 cc). Both COMS and EP917 plaque linear fits were good (r2 = .967 and .957); the largest deviations were seen for large volumes. Conclusions: The method outlined here is effective for checking planning consistency and quality assurance of two types of LDR brachytherapy treatment plans (temporary and permanent). A spreadsheet for the calculations enables a quick check of the plan in situations were time is short (e.g. OR-based prostate planning)

  14. Enhancement of viability of radiosensitive (PBMC) and resistant (MDA-MB-231) clones in low-dose-rate cobalt-60 radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Falcao, Patricia Lima, E-mail: patricialfalcao@gmail.com [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil); Motta, Barbara Miranda; Lima, Fernanda Castro de; Lima, Celso Vieira; Campos, Tarcisio Passos Ribeiro [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2015-05-15

    Objective: in the present study, the authors investigated the in vitro behavior of radio-resistant breast adenocarcinoma (MDA-MB-231) cells line and radiosensitive peripheral blood mononuclear cells (PBMC), as a function of different radiation doses, dose rates and postirradiation time kinetics, with a view to the interest of clinical radiotherapy. Materials and methods: the cells were irradiated with Co-60, at 2 and 10 Gy and two different exposure rates, 339.56 cGy.min{sup -1} and the other corresponding to one fourth of the standard dose rates, present over a 10-year period of cobalt therapy. Post-irradiation sampling was performed at pre-established kinetics of 24, 48 and 72 hours. The optical density response in viability assay was evaluated and a morphological analysis was performed. Results: radiosensitive PBMC showed decrease in viability at 2 Gy, and a more significant decrease at 10 Gy for both dose rates. MDAMB-231 cells presented viability decrease only at higher dose and dose rate. The results showed MDA-MB-231 clone expansion at low dose rate after 48-72 hours post-radiation. Conclusion: low dose rate shows a possible potential clinical impact involving decrease in management of radio-resistant and radiosensitive tumor cell lines in cobalt therapy for breast cancer. (author)

  15. Enhancement of viability of radiosensitive (PBMC and resistant (MDA-MB-231 clones in low-dose-rate cobalt-60 radiation therapy

    Directory of Open Access Journals (Sweden)

    Patrícia Lima Falcão

    2015-06-01

    Full Text Available Abstract Objective: In the present study, the authors investigated the in vitro behavior of radio-resistant breast adenocarcinoma (MDA-MB-231 cells line and radiosensitive peripheral blood mononuclear cells (PBMC, as a function of different radiation doses, dose rates and postirradiation time kinetics, with a view to the interest of clinical radiotherapy. Materials and Methods: The cells were irradiated with Co-60, at 2 and 10 Gy and two different exposure rates, 339.56 cGy.min–1 and the other corresponding to one fourth of the standard dose rates, present over a 10-year period of cobalt therapy. Post-irradiation sampling was performed at pre-established kinetics of 24, 48 and 72 hours. The optical density response in viability assay was evaluated and a morphological analysis was performed. Results: Radiosensitive PBMC showed decrease in viability at 2 Gy, and a more significant decrease at 10 Gy for both dose rates. MDAMB- 231 cells presented viability decrease only at higher dose and dose rate. The results showed MDA-MB-231 clone expansion at low dose rate after 48–72 hours post-radiation. Conclusion: Low dose rate shows a possible potential clinical impact involving decrease in management of radio-resistant and radiosensitive tumor cell lines in cobalt therapy for breast cancer.

  16. High-dose 5-fluorouracil plus low dose methotrexate plus or minus low-dose PALA in advanced colorectal cancer : a randomised phase II-III trial of the EORTC Gastrointestinal Group

    NARCIS (Netherlands)

    Wils, J; Blijham, GH; Wagener, T; De Greve, J; Jansen, RLH; Kok, TC; Nortier, JWR; Bleiberg, H; Couvreur, ML; Genicot, B; Baron, B

    2003-01-01

    The aim of this study was to investigate whether N-(phosphonacetyl)-L-aspartic acid (PALA) can enhance the activity of low-dose methotrexate (LD-MTX) modulated infusional 5-fluorouracil (5-FU) in patients with advanced colorectal cancer. 198 patients were randomised either to (i) 5-FU 60 mg/kg as a

  17. [Early lung cancer detection in an occupational asbestos exposed population: clinical impact of low-dose computed tomography screening].

    Science.gov (United States)

    Pira, E; Coggiola, M; Bosio, D

    2010-01-01

    Lung cancer is the primary cause of cancer mortality in developed countries. Early detection and surgical resection is essential for the treatment of lung cancer. The introduction of low-dose spiral computed tomography (LDCT) is considered one of the most promising clinical research developments in early diagnosis of lung cancer. Our study is aimed at the evaluation of spiral CT in a cohort of subjects with a past occupational exposure to asbestos at high risk of developing lung cancer. 149 subjects were enrolled between 2007 and 2009 (the criteria for enrollment were date of birth between 1930-1961, no previous cancer and general good health, latency from the beginning of exposure > 10 years, exposure duration > 1 year, possibility to undergo to surgery). A helical low-dose CT (LDCT) of the chest was performed yearly and an evaluation protocol derived from IEO with a morphological analysis of nodules have been adopted. 13 nodules were diagnosed in the first CT, 7 in the second and 3 in the third but no invasive procedures have been taken and no lung cancer have been detected. Our early follow-up data aren't able yet to evaluate the effect of screening with LDCT on mortality but have do not confirm some of the literature initial results such as the Increase in cases of overdiagnosis (false positive) due to the high prevalence of benign lesions. PMID:21438306

  18. Low dose rate caesium-137 implant time of intracavitary brachytherapy source of a selected oncology center in Ghana

    OpenAIRE

    John Owusu Banahene; Emmanuel Ofori Darko; Baffour Awuah

    2015-01-01

    Background: The treatment time taken for a radioactive source is found to be very important in intracavitary brachytherapy treatment. The duration of the treatment time depends on the prescribed dose requested to a reference point and the calculated dose rate to the same point. The duration of the treatment time of source is found to depend on the tumour stage. In this work, the treatment time of implant has been calculated for a Caesium-137 low dose rate brachytherapy source at an oncology f...

  19. Responses of rat R-1 cells to low dose rate gamma radiation and multiple daily dose fractions

    International Nuclear Information System (INIS)

    Multifraction irradiation may offer the same therapeutic gain as continuous irradiation. Therefore, a comparison of the efficacy of low dose rate irradiation and multifraction irradiation was the main objective of the experiments to be described. Both regimens were tested on rat rhabdomyosarcoma (R-1) cells in vitro and in vivo. Exponentially growing R-1 cells were treated in vitro by a multifraction irradiation procedure with dose fractions of 2 Gy gamma radiation and time intervals of 1 to 3 h. The dose rate was 1.3 Gy.min-1. The results indicate that multifractionation of the total dose is more effective with respect to cell inactivation than continuous irradiation. (Auth.)

  20. Low-Dose Chest Computed Tomography for Lung Cancer Screening Among Hodgkin Lymphoma Survivors: A Cost-Effectiveness Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wattson, Daniel A., E-mail: dwattson@partners.org [Harvard Radiation Oncology Program, Boston, Massachusetts (United States); Hunink, M.G. Myriam [Departments of Radiology and Epidemiology, Erasmus Medical Center, Rotterdam, the Netherlands and Center for Health Decision Science, Harvard School of Public Health, Boston, Massachusetts (United States); DiPiro, Pamela J. [Department of Imaging, Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Das, Prajnan [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Hodgson, David C. [Department of Radiation Oncology, University of Toronto, Toronto, Ontario (Canada); Mauch, Peter M.; Ng, Andrea K. [Department of Radiation Oncology, Brigham and Women' s Hospital and Dana-Farber Cancer Institute, Boston, Massachusetts (United States)

    2014-10-01

    Purpose: Hodgkin lymphoma (HL) survivors face an increased risk of treatment-related lung cancer. Screening with low-dose computed tomography (LDCT) may allow detection of early stage, resectable cancers. We developed a Markov decision-analytic and cost-effectiveness model to estimate the merits of annual LDCT screening among HL survivors. Methods and Materials: Population databases and HL-specific literature informed key model parameters, including lung cancer rates and stage distribution, cause-specific survival estimates, and utilities. Relative risks accounted for radiation therapy (RT) technique, smoking status (>10 pack-years or current smokers vs not), age at HL diagnosis, time from HL treatment, and excess radiation from LDCTs. LDCT assumptions, including expected stage-shift, false-positive rates, and likely additional workup were derived from the National Lung Screening Trial and preliminary results from an internal phase 2 protocol that performed annual LDCTs in 53 HL survivors. We assumed a 3% discount rate and a willingness-to-pay (WTP) threshold of $50,000 per quality-adjusted life year (QALY). Results: Annual LDCT screening was cost effective for all smokers. A male smoker treated with mantle RT at age 25 achieved maximum QALYs by initiating screening 12 years post-HL, with a life expectancy benefit of 2.1 months and an incremental cost of $34,841/QALY. Among nonsmokers, annual screening produced a QALY benefit in some cases, but the incremental cost was not below the WTP threshold for any patient subsets. As age at HL diagnosis increased, earlier initiation of screening improved outcomes. Sensitivity analyses revealed that the model was most sensitive to the lung cancer incidence and mortality rates and expected stage-shift from screening. Conclusions: HL survivors are an important high-risk population that may benefit from screening, especially those treated in the past with large radiation fields including mantle or involved-field RT. Screening

  1. Low-Dose Chest Computed Tomography for Lung Cancer Screening Among Hodgkin Lymphoma Survivors: A Cost-Effectiveness Analysis

    International Nuclear Information System (INIS)

    Purpose: Hodgkin lymphoma (HL) survivors face an increased risk of treatment-related lung cancer. Screening with low-dose computed tomography (LDCT) may allow detection of early stage, resectable cancers. We developed a Markov decision-analytic and cost-effectiveness model to estimate the merits of annual LDCT screening among HL survivors. Methods and Materials: Population databases and HL-specific literature informed key model parameters, including lung cancer rates and stage distribution, cause-specific survival estimates, and utilities. Relative risks accounted for radiation therapy (RT) technique, smoking status (>10 pack-years or current smokers vs not), age at HL diagnosis, time from HL treatment, and excess radiation from LDCTs. LDCT assumptions, including expected stage-shift, false-positive rates, and likely additional workup were derived from the National Lung Screening Trial and preliminary results from an internal phase 2 protocol that performed annual LDCTs in 53 HL survivors. We assumed a 3% discount rate and a willingness-to-pay (WTP) threshold of $50,000 per quality-adjusted life year (QALY). Results: Annual LDCT screening was cost effective for all smokers. A male smoker treated with mantle RT at age 25 achieved maximum QALYs by initiating screening 12 years post-HL, with a life expectancy benefit of 2.1 months and an incremental cost of $34,841/QALY. Among nonsmokers, annual screening produced a QALY benefit in some cases, but the incremental cost was not below the WTP threshold for any patient subsets. As age at HL diagnosis increased, earlier initiation of screening improved outcomes. Sensitivity analyses revealed that the model was most sensitive to the lung cancer incidence and mortality rates and expected stage-shift from screening. Conclusions: HL survivors are an important high-risk population that may benefit from screening, especially those treated in the past with large radiation fields including mantle or involved-field RT. Screening

  2. [A comparative study between low-dose and high-dose medroxyprogesterone acetate (MPA) in the treatment of advanced and recurrent breast cancer--in relation to dose, serum concentration and response. Osaka Breast Cancer Research Group].

    Science.gov (United States)

    Furukawa, J; Yayoi, E; Takatsuka, Y; Aikawa, T; Maeura, Y; Kobayashi, T; Miyauchi, K; Kotsuma, Y

    1997-05-01

    A prospective randomized study was carried out to evaluate the effectiveness of MPA in the treatment of breast cancer by comparing low dose (600 mg/day) with high dose (1,200 mg/day) of MPA. In 35 evaluable cases, the response rate to treatment was 40.0% (8/20) with low dose MPA and 26.7% (4/15) with high dose MPA. There was no significant difference between the two groups. The serum MPA concentration measured by high-performance liquid chromatography (HPLC) assay was 23.2 +/- 17.6 ng/ml in the low-dose group and 89.5 +/- 56.7 ng/ml in the high-dose group. Intrapatient variability in serum MPA concentration was relatively stable, but interpatient variability was large. No correlation was found between the response rate and serum MPA concentration. The above results indicate that a low dose of MPA (600 mg/day) is a useful treatment with high effectiveness and safety in advanced and recurrent breast cancer patients. Though no exact data on the optimal serum concentration could not be obtained, it was obvious that a successful response cannot be expected from a serum MPA concentration of less than 17 ng/ml, which was the average serum concentration in NC and PD patients of the low-dose group. PMID:9170519

  3. Rat skin carcinogenesis as a basis for estimating risks at low doses and dose rates of various types of radiation

    Energy Technology Data Exchange (ETDEWEB)

    Burns, F. J.; Vanderlaan, M.; Strickland, P.; Albert, R. E.

    1976-01-01

    The recovery rate, age dependence and latent period for tumor induction in rat skin were measured for single and split doses of radiation, and the data were analyzed in terms of a general model in an attempt to estimate the expected tumor response for various types of radiation given at low dose rates for long periods of time. The dorsal skin of male rats was exposed to electrons, x rays, or protons in either single or split doses for several doses and the tumor responses were compared during 80 weeks of observation. A two stage model incorporating a reversible or recoverable mode was developed and various parameters in the model, including recovery rate, dose-response coefficients, and indices of age sensitivity, were evaluated experimentally. The measured parameters were then utilized to calculate expected tumor responses for exposure periods extending for duration of life. The calculations indicated that low dose rates could be markedly (/sup 1///sub 100/ to /sup 1///sub 1000/) less effective in producing tumors than the same dose given in a short or acute exposure, although the magnitude of the reduction in effectiveness declines as the dose declines.

  4. Treatment Outcome of Medium-Dose-Rate Intracavitary Brachytherapy for Carcinoma of the Uterine Cervix: Comparison With Low-Dose-Rate Intracavitary Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kaneyasu, Yuko, E-mail: kaneyasu@hiroshima-u.ac.jp [Department of Radiation Oncology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima (Japan); Department of Radiation Oncology, Tokyo Women' s Medical University, Tokyo (Japan); Kita, Midori [Department of Radiation Oncology, Tokyo Women' s Medical University, Tokyo (Japan); Department of Clinical Radiology, Tokyo Metropolitan Tama Medical Center, Tokyo (Japan); Okawa, Tomohiko [Evaluation and Promotion Center, Utsunomiya Memorial Hospital, Tochigi (Japan); Maebayashi, Katsuya [Department of Radiation Oncology, Tokyo Women' s Medical University, Tokyo (Japan); Kohno, Mari [Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women' s Medical University Hospital, Tokyo (Japan); Sonoda, Tatsuo; Hirabayashi, Hisae [Department of Radiology, Tokyo Women' s Medical University Hospital, Tokyo (Japan); Nagata, Yasushi [Department of Radiation Oncology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima (Japan); Mitsuhashi, Norio [Department of Radiation Oncology, Tokyo Women' s Medical University, Tokyo (Japan)

    2012-09-01

    Purpose: To evaluate and compare the efficacy of medium-dose-rate (MDR) and low-dose-rate (LDR) intracavitary brachytherapy (ICBT) for uterine cervical cancer. Methods and Materials: We evaluated 419 patients with squamous cell carcinoma of the cervix who were treated by radical radiotherapy with curative intent at Tokyo Women's Medical University from 1969 to 1999. LDR was used from 1969 to 1986, and MDR has been used since July 1987. When compared with LDR, fraction dose was decreased and fraction size was increased (1 or 2 fractions) for MDR to make the total dose of MDR equal to that of LDR. In general, the patients received a total dose of 60 to 70 Gy at Point A with external beam radiotherapy combined with brachytherapy according to the International Federation of Gynecology and Obstetrics stage. In the LDR group, 32 patients had Stage I disease, 81 had Stage II, 182 had Stage III, and 29 had Stage IVA; in the MDR group, 9 patients had Stage I disease, 19 had Stage II, 55 had Stage III, and 12 had Stage IVA. Results: The 5-year overall survival rates for Stages I, II, III, and IVA in the LDR group were 78%, 72%, 55%, and 34%, respectively. In the MDR group, the 5-year overall survival rates were 100%, 68%, 52%, and 42%, respectively. No significant statistical differences were seen between the two groups. The actuarial rates of late complications Grade 2 or greater at 5 years for the rectum, bladder, and small intestine in the LDR group were 11.1%, 5.8%, and 2.0%, respectively. The rates for the MDR group were 11.7%, 4.2%, and 2.6%, respectively, all of which were without statistical differences. Conclusion: These data suggest that MDR ICBT is effective, useful, and equally as good as LDR ICBT in daytime (about 5 hours) treatments of patients with cervical cancer.

  5. Clinical application of low-dose CT combined with computer-aided detection in lung cancer screening

    International Nuclear Information System (INIS)

    Objective: To investigate the clinical value of chest low-dose CT (LDCT) combined with computer-aided detection (CAD) system for lung cancer screening in high risk population. Methods: Two hundred and nineteen healthy candidates underwent 64-slice LDCT scan. All images were reviewed in consensus by two radiologists with 15 years of thoracic CT diagnosis experience. Then the image data were analyzed with CAD alone. Finally images were reviewed by two radiologists with 5 years of CT diagnosis experience with and without CT Viewer software. The sensitivity, false positive rate of CAD for pulmonary nodule detection were calculated. SPSS 11.5 software and Chi-square test were used for the statistics. Results: Of 219 candidates ,104(47.5% ) were detected with lung nodules. There were 366 true nodules confirmed by the senior radiologists. The CAD system detected 271 (74.0%) true nodules and 424 false-positive nodules. The false-positive rate was 1.94/per case. The two junior radiologists indentifid 292 (79.8%), 286(78.1%) nodules without CAD and 336 (91.8%), 333 (91.0%) nodules with CAD respectively. There were significant differences for radiologists in indentifying nodules with or without CAD system (P<0.01). Conclusions: CAD is more sensitive than radiologists for indentifying the nodules in the central area or in the hilar region of the lung. While radiologists are more sensitive for the peripheral and sub-pleural nodules,or ground glass opacity nodules, or nodules smaller than 4 mm. CAD can not be used alone. The detection rate can be improved with the combination of radiologist and CAD in LDCT screen. (authors)

  6. Detection of lung cancer through low-dose CT screening (NELSON) : a prespecifi ed analysis of screening test performance and interval cancers

    NARCIS (Netherlands)

    Horeweg, Nanda; Scholten, Ernst Th; de Jong, Pim A.; van der Aalst, Carlijn M.; Weenink, Carla; Lammers, Jan-Willem J.; Nackaerts, Kristiaan; Vliegenthart, Rozemarijn; ten Haaf, Kevin; Yousaf-Khan, Uraujh A.; Heuvelmans, Marjolein A.; Thunnissen, Erik; Oudkerk, Matthijs; Mali, Willem; de Koning, Harry J.

    2014-01-01

    Background Low-dose CT screening is recommended for individuals at high risk of developing lung cancer. However, CT screening does not detect all lung cancers: some might be missed at screening, and others can develop in the interval between screens. The NELSON trial is a randomised trial to assess

  7. Investigation of bias dependence on enhanced low dose rate sensitivity in SiGe HBTs for space application

    Science.gov (United States)

    Sun, Yabin; Fu, Jun; Xu, Jun; Wang, Yudong; Zhou, Wei; Zhang, Wei; Cui, Jie; Li, Gaoqing; Liu, Zhihong

    2014-02-01

    NPN silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs) were exposed to 60Co gamma source at different dose rates under two bias conditions. Excess base currents and normalized current gains are used to quantify performance degradation. Experiment results demonstrate that the lower the dose rate, the more the irradiation damage, and some enhanced low dose rate sensitivity (ELDRS) exists in SiGe HBTs. The ELDRS effect is found to depend highly on the bias condition during exposure, and the transistors with forward active mode exhibit a more serious ELDRS effect compared to the floating case. The performance degradation at different dose rates and bias conditions is compared and discussed, and furthermore the underlying physical mechanisms are analyzed and investigated in detail.

  8. Reductions in carotid chemoreceptor activity with low-dose dopamine improves baroreflex control of heart rate during hypoxia in humans.

    Science.gov (United States)

    Mozer, Michael T; Holbein, Walter W; Joyner, Michael J; Curry, Timothy B; Limberg, Jacqueline K

    2016-07-01

    The purpose of the present investigation was to examine the contribution of the carotid body chemoreceptors to changes in baroreflex control of heart rate with exposure to hypoxia. We hypothesized spontaneous cardiac baroreflex sensitivity (scBRS) would be reduced with hypoxia and this effect would be blunted when carotid chemoreceptor activity was reduced with low-dose dopamine. Fifteen healthy adults (11 M/4 F) completed two visits randomized to intravenous dopamine or placebo (saline). On each visit, subjects were exposed to 5-min normoxia (~99% SpO2), followed by 5-min hypoxia (~84% SpO2). Blood pressure (intra-arterial catheter) and heart rate (ECG) were measured continuously and scBRS was assessed by spectrum and sequence methodologies. scBRS was reduced with hypoxia (P  0.05). Present findings are consistent with a reduction in scBRS with systemic hypoxia. Furthermore, we show this effect is partially mediated by the carotid body chemoreceptors, given the fall in scBRS is attenuated when activity of the chemoreceptors is reduced with low-dose dopamine. However, the improvement in scBRS with dopamine appears to be specific to rising blood pressures. These results may have important implications for impairments in baroreflex function common in disease states of acute and/or chronic hypoxemia, as well as the experimental use of dopamine to assess such changes.

  9. Long-term results of concurrent chemoradiotherapy using low-dose continuous infusion of 5-fluorouracil for stage II-III esophageal cancer

    International Nuclear Information System (INIS)

    To improve the local control of stage II-III esophageal cancer, we tried concurrent chemoradiotherapy with low-dose continuous infusion of 5-fluorouracil (5-FU) during the entire course of conventional radiotherapy. Forty-three eligible patients with stage II-III esophageal cancer were treated with conventional radiotherapy up to 60-70 Gy concurrently with continuous infusion of 5-FU (300 mg/m2 per 24 hours) for 5 days per week given over 5 to 7 weeks. All patients were followed up more than 5 years after starting the treatments. Although there were two treatment-related deaths, 88% of the patients (38/43) could complete the planned course of chemoradiotherapy. Response rate was 90%. The median survival time was 12.2 months, and the 2- and 5-year overall survival rates were 33% and 15%, respectively. Low-dose continuous infusion of 5-FU given during the entire course of conventional radiotherapy is feasible and seems to offer better results than radiotherapy alone in the treatment of stage II-III esophageal cancer. (author)

  10. DoReMi workshop on multidisciplinary approaches to evaluating cancer risks associated with low-dose internal contamination

    International Nuclear Information System (INIS)

    A workshop dedicated to cancer risks associated with low-dose internal contamination was organised in March 2011, in Paris, in the framework of the DoReMi (Low Dose Research towards Multidisciplinary Integration) European Network of Excellence. The aim was to identify the best epidemiological studies that provide an opportunity to develop a multidisciplinary approach to improve the evaluation of the cancer risk associated with internal contamination. This workshop provided an opportunity for in-depth discussions between researchers working in different fields including (but not limited to) epidemiology, dosimetry, biology and toxicology. Discussions confirmed the importance of research on the health effects of internal contamination. Several existing epidemiological studies provide a real possibility to improve the quantification of cancer risk associated with internal emitters. Areas for future multidisciplinary collaborations were identified, that should allow feasibility studies to be carried out in the near future. The goal of this paper is to present an overview of the presentations and discussions that took place during this workshop. (authors)

  11. Experimental long-term exposures of fish to low dose rate gamma- or alpha-radiation

    International Nuclear Information System (INIS)

    While it is well known that α-radiation is much more damaging than γ-radiation (on an equal absorbed dose basis) to man and mammals, there are no data available to compare the effects of these radiations on fish. As many authorised disposals of radioactivity are made to sea or rivers and include α- and γ-emitters it is important that such data is obtained so that estimates of the combined biological damaging effects may be made. This paper describes experiments made to examine the comparative effects of chronic exposure to α- or γ-radiation on reproductive endpoints in a representative fish, the zebrafish Danio rerio. Fish were exposed to γ-radiation or α-radiation for approximately 1 year. The fish were allowed to breed once per week and for each breeding opportunity the total numbers of eggs, numbers of eggs viable at 24 hours and eggs hatching successfully were recorded. Dose rate groups were 300, 1000 or 7400μGy h-1 for γ-radiation and 9.6, 19, 84 and 214μGy h-1 for α-radiation. None of the α-radiation groups showed significant effects on any measure of egg production while among γ-radiation groups only the highest, 7400μGy h-1 group showed an effect. This was a rapid decrease in total number of eggs and viable eggs laid per opportunity, leading to a failure to lay any after 20 weekly opportunities. There was, however, no significant decrease in any group in the hatch rate of eggs which were viable at 24 hours. Comparison of the highest α-radiation dose rate which produced no effect (214μGy h-1) and the γ-radiation dose rate which had a significant effect (7400μGy h-1) gives a relative biological effect (RBEα) of <35. (author)

  12. Morbidity rate of nervous system among medical personnel occupationally exposed to chronic low dose irradiation

    International Nuclear Information System (INIS)

    The morbidity rate of the nervous system among 1190 subjects, medical personnel, working with sources and environment of ionizing radiation was studied by the personal analysis of the diseases, written down in the personal out-patient department cards as well as of a control group of 870 medical workers of various other specialities. The morbidity rate of the nervous system among the medical personnel, exposed to chronic occupational radiation effect, was established not to be higher than that of the other medical workers - 38.0 and 40.3% respectively. Neuroses and peripheral nervous diseases have the greatest relative share in the structure of morbidity rate of the nervous system in both groups examined, with no statistical significance in the differences of the indices. The significantly higher incidence of autonome dystonias, established among the personnel from the X-ray departments and consulting rooms could be discussed in connection with the great relative share of the subjects from that group with a length of service over 15 years and had received the possible maximum cumulative equivalent doses. 3 tabs., 21 refs

  13. Effect of low dose oxytocin treatment on the pregnancy rate of the dairy cows

    Directory of Open Access Journals (Sweden)

    H. Hamali,

    2011-02-01

    Full Text Available It is well known that during the natural mating, stimulation of the female genital system by the bull causes oxytocin release from the caudal part of the female pituitary gland and this hormone enhances the sperm transport in the genital tract. During the artificial insemination (A.I, this hormone dose not release perfectly. For determine of the oxytocin effect on the pregnancy rates of the cows, a total 100 cows were chosen in a dairy herd located in a suburb of Tabriz (North-west of Iran. These cows were randomly divided into two groups. In the group A, during the A.I, 30 IU oxytocin (3cc Vetocin was injected to the cows intramuscularly. In the group of B, 3cc saline was injected intramuscularly to the control cows. After 45 days of A.I, all of the cows were examined by rectal palpation for pregnancy detection. The pregnancy rates were 58% and 54% in the groups of oxytocin treated and control respectively. The difference between two groups did not differ significantly. These results indicated that oxytocin administration during the A.I had not significant effect on the cow's pregnancy rates.

  14. Low doses of caffeine reduce heart rate during submaximal cycle ergometry

    Directory of Open Access Journals (Sweden)

    Wetter Thomas J

    2007-10-01

    Full Text Available Abstract Background The purpose of this study was to examine the cardiovascular effects of two low-levels of caffeine ingestion in non habitual caffeine users at various submaximal and maximal exercise intensities. Methods Nine male subjects (19–25 yr; 83.3 ± 3.1 kg; 184 ± 2 cm, underwent three testing sessions administered in a randomized and double-blind fashion. During each session, subjects were provided 4 oz of water and a gelatin capsule containing a placebo, 1.5 mg/kg caffeine, or 3.0 mg/kg caffeine. After thirty minutes of rest, a warm-up (30 Watts for 2 min the pedal rate of 60 rpm was maintained at a steady-state output of 60 watts for five minutes; increased to 120 watts for five minutes and to 180 watts for five minutes. After a 2 min rest the workload was 180 watts for one minute and increased by 30 watts every minute until exhaustion. Heart rate (HR was measured during the last 15-seconds of each minute of submaximal exercise. Systolic blood pressure (BP was measured at rest and during each of the three sub-maximal steady state power outputs. Minute ventilation (VE, Tidal volume (VT, Breathing frequency (Bf, Rating of perceived exertion (RPE, Respiratory exchange ratio (RER, and Oxygen consumption (VO2 were measured at rest and during each minute of exercise. Results Caffeine at 1.5 and 3.0 mg/kg body weight significantly lowered (p E, VT, VO2, RPE, maximal power output or time to exhaustion. Conclusion In non habitual caffeine users it appears that consuming a caffeine pill (1.5 & 3.0 mg/kg at a dose comparable to 1–3 cups of coffee lowers heart rate during submaximal exercise but not at near maximal and maximal exercise. In addition, this caffeine dose also only appears to affect systolic blood pressure at rest but not during cycling exercise.

  15. Fast radioactive seed localization in intraoperative cone beam CT for low-dose-rate prostate brachytherapy

    Science.gov (United States)

    Hu, Yu-chi; Xiong, Jian-ping; Cohan, Gilad; Zaider, Marco; Mageras, Gig; Zelefsky, Michael

    2013-03-01

    A fast knowledge-based radioactive seed localization method for brachytherapy was developed to automatically localize radioactive seeds in an intraoperative volumetric cone beam CT (CBCT) so that corrections, if needed, can be made during prostate implant surgery. A transrectal ultrasound (TRUS) scan is acquired for intraoperative treatment planning. Planned seed positions are transferred to intraoperative CBCT following TRUS-to-CBCT registration using a reference CBCT scan of the TRUS probe as a template, in which the probe and its external fiducial markers are pre-segmented and their positions in TRUS are known. The transferred planned seeds and probe serve as an atlas to reduce the search space in CBCT. Candidate seed voxels are identified based on image intensity. Regions are grown from candidate voxels and overlay regions are merged. Region volume and intensity variance is checked against known seed volume and intensity profile. Regions meeting the above criteria are flagged as detected seeds; otherwise they are flagged as likely seeds and sorted by a score that is based on volume, intensity profile and distance to the closest planned seed. A graphical interface allows users to review and accept or reject likely seeds. Likely seeds with approximately twice the seed volume are automatically split. Five clinical cases are tested. Without any manual correction in seed detection, the method performed the localization in 5 seconds (excluding registration time) for a CBCT scan with 512×512×192 voxels. The average precision rate per case is 99% and the recall rate is 96% for a total of 416 seeds. All false negative seeds are found with 15 in likely seeds and 1 included in a detected seed. With the new method, updating of calculations of dose distribution during the procedure is possible and thus facilitating evaluation and improvement of treatment quality.

  16. Characterizing low dose and dose rate effects in rodent and human neural stem cells exposed to proton and gamma irradiation

    Directory of Open Access Journals (Sweden)

    Bertrand P. Tseng

    2013-01-01

    Full Text Available Past work has shown that exposure to gamma rays and protons elicit a persistent oxidative stress in rodent and human neural stem cells (hNSCs. We have now adapted these studies to more realistic exposure scenarios in space, using lower doses and dose rates of these radiation modalities, to further elucidate the role of radiation-induced oxidative stress in these cells. Rodent neural stem and precursor cells grown as neurospheres and human neural stem cells grown as monolayers were subjected to acute and multi-dosing paradigms at differing dose rates and analyzed for changes in reactive oxygen species (ROS, reactive nitrogen species (RNS, nitric oxide and superoxide for 2 days after irradiation. While acute exposures led to significant changes in both cell types, hNSCs in particular, exhibited marked and significant elevations in radiation-induced oxidative stress. Elevated oxidative stress was more significant in hNSCs as opposed to their rodent counterparts, and hNSCs were significantly more sensitive to low dose exposures in terms of survival. Combinations of protons and γ-rays delivered as lower priming or higher challenge doses elicited radioadaptive changes that were associated with improved survival, but in general, only under conditions where the levels of reactive species were suppressed compared to cells irradiated acutely. Protective radioadaptive effects on survival were eliminated in the presence of the antioxidant N-acetylcysteine, suggesting further that radiation-induced oxidative stress could activate pro-survival signaling pathways that were sensitive to redox state. Data corroborates much of our past work and shows that low dose and dose rate exposures elicit significant changes in oxidative stress that have functional consequences on survival.

  17. Reductions in carotid chemoreceptor activity with low-dose dopamine improves baroreflex control of heart rate during hypoxia in humans.

    Science.gov (United States)

    Mozer, Michael T; Holbein, Walter W; Joyner, Michael J; Curry, Timothy B; Limberg, Jacqueline K

    2016-07-01

    The purpose of the present investigation was to examine the contribution of the carotid body chemoreceptors to changes in baroreflex control of heart rate with exposure to hypoxia. We hypothesized spontaneous cardiac baroreflex sensitivity (scBRS) would be reduced with hypoxia and this effect would be blunted when carotid chemoreceptor activity was reduced with low-dose dopamine. Fifteen healthy adults (11 M/4 F) completed two visits randomized to intravenous dopamine or placebo (saline). On each visit, subjects were exposed to 5-min normoxia (~99% SpO2), followed by 5-min hypoxia (~84% SpO2). Blood pressure (intra-arterial catheter) and heart rate (ECG) were measured continuously and scBRS was assessed by spectrum and sequence methodologies. scBRS was reduced with hypoxia (P dopamine (P dopamine (P dopamine did not attenuate the decrease in baroreflex sensitivity to falling pressures (scBRS "down-down"; P > 0.05). Present findings are consistent with a reduction in scBRS with systemic hypoxia. Furthermore, we show this effect is partially mediated by the carotid body chemoreceptors, given the fall in scBRS is attenuated when activity of the chemoreceptors is reduced with low-dose dopamine. However, the improvement in scBRS with dopamine appears to be specific to rising blood pressures. These results may have important implications for impairments in baroreflex function common in disease states of acute and/or chronic hypoxemia, as well as the experimental use of dopamine to assess such changes. PMID:27418545

  18. High dose and low dose radiation exposure in the induction of breast cancer

    International Nuclear Information System (INIS)

    In today's modern practice of Radiation Oncology it is becoming increasingly common to follow many patients with breast cancer. There is a proven association between prior radiation and the development of breast cancer, although in many instances the available sources of data are confusing. Characteristic features of radiation induced breast cancer are the importance of age at first exposure to radiation and the long latency period. The risk of breast cancer is highest in women exposed in the first decade of life and lessens progressively with increased age at exposure. The latency period is typically 10 years or more; a time in which other age dependent factors may influence the expression of the malignant phenotype. Genetic factors may also (in theory) increase a particular patient's susceptibility. (author)

  19. Genetic effect of low dose rate radiation on human cells immortalized with the hTERT gene

    International Nuclear Information System (INIS)

    We established immortal human cells by introducing the hTERT gene into skin fibroblast cells obtained from normal (SuSa) and ataxia telangiectasia (AT: AT1OS) individuals of Japanese origin. These immortalized cells showed the same characteristics as the original cells except expanded life span. We irradiated SuSa/T-n and AT1OS/T-n cells with low-dose-rate (LDR; 0.3 mGy/min) irradiation at confluent state in low-serum medium. Then, survival rate and micronucleus frequency of each cell line were analyzed. In SuSa/T-n cells, frequency of HPRT mutation induction was also determined by 6TG selection. In SuSa/T-n cells, survival rate and micronucleus frequency showed higher resistance after irradiation with LDR than high-dose-rate (HDR; 2 Gy/min) irradiation. In contrast, no significant difference was observed in survival and micronucleus induction in AT1OS/T-n cells between HDR and LDR irradiation, suggesting that AT1OS/T-n cells may have some defect in DNA repair activity. In SuSa/T-n cells, the frequency of HPRT mutation after LDR irradiation decreased to approximately one eighth that after HDR irradiation. (author)

  20. Exposure to low-dose radiation and the risk of breast cancer among women with a familial or genetic predisposition: a meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jansen-van der Weide, Marijke C. [University Medical Center Groningen, University of Groningen, Department of Radiology, Hanzeplein 1, PO Box 30.001, Groningen (Netherlands); University Medical Center Groningen, University of Groningen, Department of Epidemiology, Groningen (Netherlands); Greuter, Marcel J.W.; Pijnappel, Ruud M. [University Medical Center Groningen, University of Groningen, Department of Radiology, Hanzeplein 1, PO Box 30.001, Groningen (Netherlands); Jansen, Liesbeth [University Medical Center Groningen, University of Groningen, Department of Surgery, Groningen (Netherlands); Oosterwijk, Jan C. [University Medical Center Groningen, University of Groningen, Department of Clinical Genetics, Groningen (Netherlands); Bock, Geertruida H. de [University Medical Center Groningen, University of Groningen, Department of Epidemiology, Groningen (Netherlands)

    2010-11-15

    Women with familial or genetic aggregation of breast cancer are offered screening outside the population screening programme. However, the possible benefit of mammography screening could be reduced due to the risk of radiation-induced tumours. A systematic search was conducted addressing the question of how low-dose radiation exposure affects breast cancer risk among high-risk women. A systematic search was conducted for articles addressing breast cancer, mammography screening, radiation and high-risk women. Effects of low-dose radiation on breast cancer risk were presented in terms of pooled odds ratios (OR). Of 127 articles found, 7 were selected for the meta-analysis. Pooled OR revealed an increased risk of breast cancer among high-risk women due to low-dose radiation exposure (OR = 1.3, 95% CI: 0.9- 1.8). Exposure before age 20 (OR = 2.0, 95% CI: 1.3-3.1) or a mean of {>=}5 exposures (OR = 1.8, 95% CI: 1.1-3.0) was significantly associated with a higher radiation-induced breast cancer risk. Low-dose radiation increases breast cancer risk among high-risk women. When using low-dose radiation among high-risk women, a careful approach is needed, by means of reducing repeated exposure, avoidance of exposure at a younger age and using non-ionising screening techniques. (orig.)

  1. Low-dose vaginal estrogens or vaginal moisturizer in breast cancer survivors with urogenital atrophy: a preliminary study.

    Science.gov (United States)

    Biglia, Nicoletta; Peano, Elisa; Sgandurra, Paola; Moggio, Giulia; Panuccio, Enrico; Migliardi, Marco; Ravarino, Nicoletta; Ponzone, Riccardo; Sismondi, Piero

    2010-06-01

    The study aim is to evaluate the efficacy and safety of two low-dose vaginal estrogen treatments (ETs) and of a non-hormonal vaginal moisturizer in postmenopausal breast cancer survivors with urogenital atrophy. Eighteen patients receiving estriol cream 0.25 mg (n = 10) or estradiol tablets 12.5 microg (n = 8) twice/week for 12 weeks were evaluated and compared with eight patients treated with polycarbophil-based moisturizer 2.5 g twice/week. Severity of vaginal atrophy was assessed using subjective [Vaginal Symptoms Score (VSS), Profile of Female Sexual Function (PFSF)] and objective [Vaginal Health Index (VHI), Karyopycnotic Index (KI)] evaluations, while safety by measuring endometrial thickness and serum sex hormones levels. After 4 weeks, VSS and VHI were significantly improved by both vaginal ETs, with further improvement after 12 weeks. PFSF improved significantly only in estriol group (p = 0.02). Safety measurements did not significantly change. Vaginal moisturizer improved VSS at week 4 (p = 0.01), but score returned to pre-treatment values at week 12; no significant modification of VHI, KI, PFSF was recorded. Both low-dose vaginal ET are effective for relieving urogenital atrophy, while non-hormonal moisturizer only provides transient benefit. The increase of serum estrogens levels during treatment with vaginal estrogen at these dosages is minimal.

  2. Experiences of low dose exposure mammography on the cancer mass screening of breast

    International Nuclear Information System (INIS)

    This paper summarizes experiences in the use of the mammograph for the mass screening of breast cancer. The exposure dose per experience was only 1/8.4 (0.21 mSv) that of conventional mammography. Application to 243 persons resulted in 95.6% (43/45 patients) of TPR, 57.1% (113/198 patients) of TNR and 1.7% (2/115 patients) of false negative. Although the authors consider that the mammograph has a bright future, a few points for improvement follow herein. To increase the accuracy of mass screening of breast cancer, photography techniques and decipherment of X-rays should be considered. (author)

  3. Biology responses to low dose radiation

    International Nuclear Information System (INIS)

    Biology responses to low dose radiation is the most important problem of medical radiation and radiation protection. The especial mechanism of low dose or low dose rate induced cell responses, has been found independent with linear no-threshold model. This article emphasize to introduce low dose or low dose rate induced biology responses of adaptive response, by-effect, super-sensitivity and genomic instability. (authors)

  4. In Vitro Cytotoxicity of Low-Dose-Rate Radioimmunotherapy by the Alpha-Emitting Radioimmunoconjugate Thorium-227-DOTA-Rituximab

    International Nuclear Information System (INIS)

    Purpose: To determine whether the low-dose-rate α-particle-emitting radioimmunoconjugate 227Th-1,4,7,10-p-isothiocyanato-benzyl-tetraazacyclododecane-1,4,7, 10-tetraacetic acid (DOTA)-rituximab can be used to inactivate lymphoma cells growing as single cells and small colonies. Methods and Materials: CD20-positive lymphoma cell lines were treated with 227Th-DOTA-rituximab for 1-5 weeks. To simulate the in vivo situation with continuous but decreasing supply of radioimmunoconjugates from the blood pool, the cells were not washed after incubation with 227Th-DOTA-rituximab, but half of the medium was replaced with fresh medium, and cell concentration and cell-bound activity were determined every other day after start of incubation. A microdosimetric model was established to estimate the average number of hits in the nucleus for different localizations of activity. Results: There was a specific targeted effect on cell growth of the 227Th-DOTA-rituximab treatment. Although the cells were not washed after incubation with 227Th-DOTA-rituximab, the average contribution of activity in the medium to the mean dose was only 6%, whereas the average contribution from activity on the cells' own surface was 78%. The mean dose rates after incubation with 800 Bq/mL 227Th-DOTA-rituximab varied from 0.01 to 0.03 cGy/min. The average delay in growing from 105 to 107 cells/mL was 15 days when the cells were treated with a mean absorbed radiation dose of 2 Gy α-particle radiation from 227Th-DOTA-rituximab, whereas it was 11 days when the cells were irradiated with 6 Gy of X-radiation. The relative biologic effect of the treatment was estimated to be 2.9-3.4. Conclusions: The low-dose-rate radioimmunoconjugate 227Th-DOTA-rituximab is suitable for inactivation of single lymphoma cells and small colonies of lymphoma cells.

  5. Retrospective Analysis of Local Control and Cosmetic Outcome of 147 Periorificial Carcinomas of the Face Treated With Low-Dose Rate Interstitial Brachytherapy

    International Nuclear Information System (INIS)

    Purpose: Skin cancer is the most common malignancy in white populations. We evaluated the local cure rate and cosmetic outcome of patients with basal cell carcinoma (BCC) or squamous cell carcinoma (SCC) of the face treated with low-dose rate brachytherapy. Methods and Materials: Between February 1990 and May 2000, 147 facial carcinomas in 132 patients were treated by 192Ir wire implantation. Side effects of brachytherapy were noted. Follow-up was 2 years or more. Locoregional recurrence-free survival (LRFS) and overall survival were recorded. Group A included patients treated by primary brachytherapy, and Group B included those treated after recurrence. Results: A total of 121 carcinomas were BCCs (82.3%) and 26 were SCCs (17.7%); the median tumor size was 10 mm. Of the tumors, 86 (58.5%) were in men and 61 (41.5%) were in women; the median age was 71 years. Group A comprised 116 lesions (78.9%), and Group B, 31 (21.1%). There were 17 relapses (11.6%) after a median follow-up of 72 months: 12 local, 4 nodal, and 1 local and nodal. Locoregional-free survival was 96.6% at 2 years and 87.3% at 5 years. Five-year LRFS was 82.6% in men and 93.3% in women (p = 0.027). After adjustment for gender, LRFS was better after primary treatment than after recurrence (hasard ratio HR, 2.91; 95% confidence interval, 1.06-8.03; p = 0.039). Five-year LRFS was 90.4% for BCC and 70.8% for SCC (p = 0.03). There were no Grade 3 complications. Conclusions: Low-dose rate brachytherapy offers good local control and cosmetic outcome in patients with periorificial skin carcinomas, with no Grade 3 complications. Brchytherapy is more efficient when used as primary treatment.

  6. Effects of low doses

    International Nuclear Information System (INIS)

    Actually, even though it is comfortable for the risk management, the hypothesis of the dose-effect relationship linearity is not confirmed for any model. In particular, in the area of low dose rate delivered by low let emitters. this hypothesis is debated at the light of recent observations, notably these ones relative to the mechanisms leading to genetic instability and induction eventuality of DNA repair. The problem of strong let emitters is still to solve. (N.C.)

  7. To Screen or not to Screen: Low Dose Computed Tomography in Comparison to Chest Radiography or Usual Care in Reducing Morbidity and Mortality from Lung Cancer

    Science.gov (United States)

    Kamdar, Jay; Moats, Austin; Nguyen, Brenda

    2016-01-01

    Lung cancer has the highest mortality rate of all cancers. This paper seeks to address the question: Can the mortality of lung cancer be decreased by screening with low-dose computerized tomography (LDCT) in higher risk patients compared to chest X-rays (CXR) or regular patient care? Currently, CXR screening is recommended for certain high-risk patients. Several recent trials have examined the effectiveness of LDCT versus chest radiography or usual care as a control. These trials include National Lung Screening Trial (NLST), Detection And screening of early lung cancer with Novel imaging TEchnology (DANTE), Lung Screening Study (LSS), Depiscan, Italian Lung (ITALUNG), and Dutch-Belgian Randomized Lung Cancer Screening Trial (Dutch acronym: NELSON study). NLST, the largest trial (n=53, 454), demonstrated a decrease in mortality from lung cancer in the LDCT group (RRR=20%, P=0.004). LSS demonstrated a greater sensitivity in detecting both early stage and any stage of lung cancer in comparison to traditional CXR. Although the DANTE trial yielded data consistent with findings in LSS, it also showed that via LDCT screening a greater proportion of patients were placed under unnecessary surgical procedures. The Depiscan trial yielded a high nodule detection rate at the cost of a high false-positive rate compared to CXR screening. The ITALUNG and NELSON trials demonstrated the early detection capabilities of LDCT for lung cancers compared to usual care without surveillance imaging. False-positive findings with unnecessary workup, intervention, and radiation exposure remain significant concerns for routine LDCT screening. However, current data suggests LDCT may provide a highly sensitive and specific means for detecting lung cancers and reducing mortality. PMID:27375974

  8. To Screen or not to Screen: Low Dose Computed Tomography in Comparison to Chest Radiography or Usual Care in Reducing Morbidity and Mortality from Lung Cancer.

    Science.gov (United States)

    Dajac, Joshua; Kamdar, Jay; Moats, Austin; Nguyen, Brenda

    2016-01-01

    Lung cancer has the highest mortality rate of all cancers. This paper seeks to address the question: Can the mortality of lung cancer be decreased by screening with low-dose computerized tomography (LDCT) in higher risk patients compared to chest X-rays (CXR) or regular patient care? Currently, CXR screening is recommended for certain high-risk patients. Several recent trials have examined the effectiveness of LDCT versus chest radiography or usual care as a control. These trials include National Lung Screening Trial (NLST), Detection And screening of early lung cancer with Novel imaging TEchnology (DANTE), Lung Screening Study (LSS), Depiscan, Italian Lung (ITALUNG), and Dutch-Belgian Randomized Lung Cancer Screening Trial (Dutch acronym: NELSON study). NLST, the largest trial (n=53, 454), demonstrated a decrease in mortality from lung cancer in the LDCT group (RRR=20%, P=0.004). LSS demonstrated a greater sensitivity in detecting both early stage and any stage of lung cancer in comparison to traditional CXR. Although the DANTE trial yielded data consistent with findings in LSS, it also showed that via LDCT screening a greater proportion of patients were placed under unnecessary surgical procedures. The Depiscan trial yielded a high nodule detection rate at the cost of a high false-positive rate compared to CXR screening. The ITALUNG and NELSON trials demonstrated the early detection capabilities of LDCT for lung cancers compared to usual care without surveillance imaging. False-positive findings with unnecessary workup, intervention, and radiation exposure remain significant concerns for routine LDCT screening. However, current data suggests LDCT may provide a highly sensitive and specific means for detecting lung cancers and reducing mortality. PMID:27375974

  9. Case of ileal perforation during low dose irradiation for pelvic recurrence of rectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hosokawa, Tetsuya; Kobatake, Toshio; Isomoto, Hiroharu; Shirouzu, Kazuo; Kakegawa, Teruo

    1989-01-01

    A 42-year-old man was evaluated for perineal pain. Computed tomography of the pelvis revealed recurrence of rectal cancer, which was impossible to treat sugically. Though irradiation therapy was started. As it had to be discontinued because of the appearance of inflammation in the perineal region and lower abdominal pain after 800 rad. Small intestinal gastrography revealed a perforation of the ileum, and intestinal resection was performed. Pathological studies showed cancer invasion, bleeding and edema due to acute radiation damage. The radiosensitive nature of the small intestine in this case led to a fatal outcome. Effective therapeutic and examination methods have not yes been established for cases such as this one. It is concluded that lowdose radiation may induce severe intestinal complications. (author).

  10. A case of ileal perforation during low dose irradiation for pelvic recurrence of rectal cancer

    International Nuclear Information System (INIS)

    A 42-year-old man was evaluated for perineal pain. Computed tomography of the pelvis revealed recurrence of rectal cancer, which was impossible to treat sugically. Though irradiation therapy was started. As it had to be discontinued because of the appearance of inflammation in the perineal region and lower abdominal pain after 800 rad. Small intestinal gastrography revealed a perforation of the ileum, and intestinal resection was performed. Pathological studies showed cancer invasion, bleeding and edema due to acute radiation damage. The radiosensitive nature of the small intestine in this case led to a fatal outcome. Effective therapeutic and examination methods have not yes been established for cases such as this one. It is concluded that lowdose radiation may induce severe intestinal complications. (author)

  11. The risk of childhood cancer from low doses of ionizing radiation received in utero

    International Nuclear Information System (INIS)

    Radiological protection is based upon the assumption that any additional exposure to ionising radiation leads to an increased risk of stochastic adverse health effects. The validity of this assumption is supported by the epidemiological association between childhood cancer and X-ray exposure of the fetus in utero for diagnostic purposes. Evidence for a direct causal interpretation of this association is compelling: the association has high statistical significance, it is consistent across many case-control studies carried out worldwide, and an appropriate dose-response relationship is indicated. Evidence against bias and confounding as alternative explanations is strong. Nonetheless, objections to causality have been raised. Four grounds for controversy are examined in detail, with the conclusion that they do not provide persuasive evidence against a cause and effect relationship. We conclude that acute doses of the order of 10 mGy received by the fetus in utero cause a subsequent increase in the risk of cancer in childhood, and that, in these circumstances, the excess absolute risk coefficient for childhood cancer incidence is 6-12% per Gy. (author)

  12. Hepatic intra-arterial chemotherapy (HIAC) of high dose mitomycin and epirubicin combined with caval chemofiltration versus prolonged low doses in liver metastases from colorectal cancer: a prospective randomized clinical study.

    Science.gov (United States)

    Fiorentini, G; Poddie, D B; Cantore, M; Rossi, S; Tumolo, S; Dentico, P; Bernardeschi, P; Guadagni, S; Rossi, G; Valori, V M; De Simone, M

    2004-11-01

    A multicenter randomized study comparing high dose of mitomycin and epirubicin given as hepatic intra-arterial chemotherapy (HIAC) combined with caval chemofiltration (CF) versus low doses of the same drugs in unresectable liver metastases from colorectal cancer showed a significant improvement in the survival rate of the 20 patients treated with high dose compared to the 22 patients treated with low doses with a 1 year survival of 69% vs 39%. The median survival was 17 vs 11 months and the responses were 65% vs 33%. Toxicity was colangitis in 50% of patients considered. The extrahepatic progression was similar in the two groups (7/20 vs 8/22). PMID:15675479

  13. MPGD for breast cancer prevention: a high resolution and low dose radiation medical imaging

    Science.gov (United States)

    Gutierrez, R. M.; Cerquera, E. A.; Mañana, G.

    2012-07-01

    Early detection of small calcifications in mammograms is considered the best preventive tool of breast cancer. However, existing digital mammography with relatively low radiation skin exposure has limited accessibility and insufficient spatial resolution for small calcification detection. Micro Pattern Gaseous Detectors (MPGD) and associated technologies, increasingly provide new information useful to generate images of microscopic structures and make more accessible cutting edge technology for medical imaging and many other applications. In this work we foresee and develop an application for the new information provided by a MPGD camera in the form of highly controlled images with high dynamical resolution. We present a new Super Detail Image (S-DI) that efficiently profits of this new information provided by the MPGD camera to obtain very high spatial resolution images. Therefore, the method presented in this work shows that the MPGD camera with SD-I, can produce mammograms with the necessary spatial resolution to detect microcalcifications. It would substantially increase efficiency and accessibility of screening mammography to highly improve breast cancer prevention.

  14. Longitudinal follow-up study of smoking-induced emphysema progression in low-dose CT screening of lung cancer

    Science.gov (United States)

    Suzuki, H.; Matsuhiro, M.; Kawata, Y.; Niki, N.; Nakano, Y.; Ohmatsu, H.; Kusumoto, M.; Tsuchida, T.; Eguchi, K.; Kaneko, Masahiro; Moriyama, N.

    2014-03-01

    Chronic obstructive pulmonary disease is a major public health problem that is predicted to be third leading cause of death in 2030. Although spirometry is traditionally used to quantify emphysema progression, it is difficult to detect the loss of pulmonary function by emphysema in early stage, and to assess the susceptibility to smoking. This study presents quantification method of smoking-induced emphysema progression based on annual changes of low attenuation volume (LAV) by each lung lobe acquired from low-dose CT images in lung cancer screening. The method consists of three steps. First, lung lobes are segmented using extracted interlobar fissures by enhancement filter based on fourdimensional curvature. Second, LAV of each lung lobe is segmented. Finally, smoking-induced emphysema progression is assessed by statistical analysis of the annual changes represented by linear regression of LAV percentage in each lung lobe. This method was applied to 140 participants in lung cancer CT screening for six years. The results showed that LAV progressions of nonsmokers, past smokers, and current smokers are different in terms of pack-year and smoking cessation duration. This study demonstrates effectiveness in diagnosis and prognosis of early emphysema in lung cancer CT screening.

  15. Health benefits from low-dose irradiation

    International Nuclear Information System (INIS)

    Whole-body exposures of mice and humans show no harm from low doses of ionizing radiation. Forty reports show statistically significant, p < 0.01, beneficial effects when cancer and total mortality rates were examined in mice. In vitro experiments indicate that radiogenic metabolism, adaptive repair mechanisms, such as DNA repair enzymes, and the essential nature of ionizing radiation are responsible for part of this activity. However, overwhelming evidence shows that low-dose irradiation increases immune competence. Such data negate the linear concept, which has no reliable whole-animal data to support it in the low-dose range. Cell culture data are not pertinent; such cells do not have a complete immune system

  16. Concurrent chemoradiotherapy using protracted infusion of low-dose CDDP and 5-FU and radiotherapy for esophageal cancer

    International Nuclear Information System (INIS)

    We evaluated the effects and safety of concurrent chemoradiotherapy for patients with esophageal cancer. Between March 1994 and April 1998, concurrent chemoradiotherapy using protracted infusion of low-dose cisplatin (CDDP: 3-6 mg/m2/24 h), 5-fluorouracil (5-FU: 200 mg/m2/24 h) and radiotherapy was given to 26 patients. The median age was 70 yr, with a range from 58 to 86 yr. With regard to TNM classification (1987), 6 patients were stage II, 5 stage III, and 15 stage IV. Radiotherapy was performed by external irradiation alone in 23 patients and external irradiation plus brachytherapy in three patients. One patient underwent surgery after a dose of 40 Gy owing to the possibility of idiopathic bleeding from the stomach. Locally, primary effects resulted in complete response in 11 patients (42.3%) and partial response in 15 (57.7%). Acute toxicity was primarily hematologic. Leukopenia and thrombocytopenia of grade 3 of 4 occurred in eight (30.7%) and six (23.0%) of 26 patients, respectively. In patients administered CDDP at more than 5 mg/m2/day, hemotoxicity was severe because in five of the 10 patients administered 5 mg/m2 CDDP and one of the 2 patients administered 6 mg/m2 CDDP, thrombocytopenia of grade 3 or 4 occurred. Protracted infusion of low-dose CDDP and 5-FU with concomitant radiation therapy is effective, but from the point of acute toxicity, the optimal dose of CDDP and 5-FU needs further investigation. (author)

  17. Concurrent pelvic radiation with weekly low-dose cisplatin and gemcitabine as primary treatment of locally advanced cervical cancer: A phase II study

    Directory of Open Access Journals (Sweden)

    Hend EL-Hadaad

    2015-09-01

    Full Text Available Purpose: This study was done to evaluate response, compliance and survival of weekly low dose cisplatin (20 mg/m2 and gemcitabine (125 mg/m2 concurrently with pelvic radiation as primary treatment of stage IIB-IIIB cervical cancer.Methods: External radiation consisted of 50 Gy/25 fractions using 6-10 MV photon followed by 600 cGy boost to parametrium if it was still felt thickened. Then, intracavitary radiotherapy to deliver 60 Gy at point A. Chemotherapy consisted of gemcitabine at a dose of 125 mg/ m2 was given by i.v infusion over 30 minutes immediately after cisplatin 20 mg/ m2 weekly for 5 weeks during EBRT. Forty–five eligible patients received the treatment protocol. Results: Toxicity was tolerable and manageable. No grade 4 toxicity while grade 3 was recorded in hematologic one only. In order of frequency; diarrhea, nausea and vomiting, and anemia (50%, 40%, 35.5% were most common adverse events. Overall clinical response rate was 93.4% with pathological complete response of 62.2%. After median follow-up of 20 months, 2-year survival and progression-free survival rates were 90.5% and 81% respectively. Conclusion: Weekly combination of low- dose cisplatin and gemcitabine given concurrently with pelvic radiotherapy in primary treatment of locally advanced cervical cancer resulted in a high response rate with a good compliance. Further exploration is needed for the use of this approach prior to incorporating it into routine clinical care through phase III clinical trial.

  18. Low-dose natural prostaglandin F2α (dinoprost) at timed insemination improves conception rate in dairy cattle.

    Science.gov (United States)

    Ambrose, Divakar J; Gobikrushanth, Mohanathas; Zuidhof, Sjoert; Kastelic, John P

    2015-03-01

    The primary objective was to determine if low doses of PGF2α (dinoprost) given intramuscularly (im) concurrent with timed artificial insemination (TAI) would improve conception rates in dairy cattle. A secondary objective was to determine if body condition score (BCS) and parity would influence conception rates, either independently or in interaction with PGF2α treatment. In experiment I, 307 lactating Holstein cows were randomly assigned to receive either 5-mg PGF2α im (PGF2α treated, n = 154) or 0-mg PGF2α (control, n = 153) at TAI (Day 0). Blood samples were obtained on Days -10, -3, 0, and 7 to determine plasma progesterone (P4) concentrations. Pregnancy was confirmed 30 to 32 days after insemination by transrectal ultrasonography. In experiment II, 451 cows were randomly assigned to receive either 10-mg PGF2α im (PGF2α treated, n = 226) or 0-mg PGF2α (control, n = 225) at TAI, and pregnancy was confirmed 45 to 50 days after TAI by palpation per rectum. Pregnancy data were analyzed by CATMOD (SAS). In experiment I, PGF2α treatment, BCS, and parity did not affect conception rate (35.7% vs. 37.0% for PGF2α treated vs. control; P > 0.05). However, in experiment II, conception rates were higher in cows given 10-mg PGF2α than those in control cows (45.8% vs. 36.0%; P < 0.05), in cows with high BCS than in cows with low BCS (52.1% vs. 30.4%; P < 0.01), and in primiparous than in multiparous cows (47.6% vs. 34.4%; P < 0.01), but their interaction with PGF2α treatment did not affect conception rates. In summary, 5 mg of PGF2α given im concurrent with TAI failed to enhance conception rate in lactating dairy cows, whereas 10 mg of PGF2α significantly increased conception rate. PMID:25434776

  19. Low-dose natural prostaglandin F2α (dinoprost) at timed insemination improves conception rate in dairy cattle.

    Science.gov (United States)

    Ambrose, Divakar J; Gobikrushanth, Mohanathas; Zuidhof, Sjoert; Kastelic, John P

    2015-03-01

    The primary objective was to determine if low doses of PGF2α (dinoprost) given intramuscularly (im) concurrent with timed artificial insemination (TAI) would improve conception rates in dairy cattle. A secondary objective was to determine if body condition score (BCS) and parity would influence conception rates, either independently or in interaction with PGF2α treatment. In experiment I, 307 lactating Holstein cows were randomly assigned to receive either 5-mg PGF2α im (PGF2α treated, n = 154) or 0-mg PGF2α (control, n = 153) at TAI (Day 0). Blood samples were obtained on Days -10, -3, 0, and 7 to determine plasma progesterone (P4) concentrations. Pregnancy was confirmed 30 to 32 days after insemination by transrectal ultrasonography. In experiment II, 451 cows were randomly assigned to receive either 10-mg PGF2α im (PGF2α treated, n = 226) or 0-mg PGF2α (control, n = 225) at TAI, and pregnancy was confirmed 45 to 50 days after TAI by palpation per rectum. Pregnancy data were analyzed by CATMOD (SAS). In experiment I, PGF2α treatment, BCS, and parity did not affect conception rate (35.7% vs. 37.0% for PGF2α treated vs. control; P > 0.05). However, in experiment II, conception rates were higher in cows given 10-mg PGF2α than those in control cows (45.8% vs. 36.0%; P BCS than in cows with low BCS (52.1% vs. 30.4%; P < 0.01), and in primiparous than in multiparous cows (47.6% vs. 34.4%; P < 0.01), but their interaction with PGF2α treatment did not affect conception rates. In summary, 5 mg of PGF2α given im concurrent with TAI failed to enhance conception rate in lactating dairy cows, whereas 10 mg of PGF2α significantly increased conception rate.

  20. Low-dose CT screening in an Asian population with diverse risk for lung cancer: A retrospective cohort study

    International Nuclear Information System (INIS)

    To evaluate the performance of low-dose CT (LDCT) screening for lung cancer (LCA) detection in an Asian population with diverse risks for LCA. LCA screening was performed in 12,427 symptomless Asian subjects using either LDCT (5,771) or chest radiography (CXR) (6,656) in a non-trial setting. Subjects were divided into high-risk and non-high-risk groups. Data were collected on the number of patients with screening-detected LCAs and their survival in order to compare outcomes between LDCT and CXR screening with the stratification of risks considering age, sex and smoking status. In the non-high-risk group, a significant difference was observed for the detection of lung cancer (adjusted OR, 5.07; 95 % CI, 2.72-9.45) and survival (adjusted HR of LCA survival between LDCT vs. CXR group, 0.08; 95 % CI, 0.01-0.62). No difference in detection or survival of LCA was noticed in the high-risk group. LCAs in the non-high-risk group were predominantly adenocarcinomas (96 %), and more likely to be part-solid or non-solid compared with those in the high-risk group (p = 0.023). In the non-high-risk group, LDCT helps detect more LCAs and offers better survival than CXR screening, due to better detection of part solid or non-solid lung adenocarcinomas. (orig.)

  1. Low-dose CT screening in an Asian population with diverse risk for lung cancer: A retrospective cohort study

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Chin A. [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Seoul (Korea, Republic of); Lee, Kyung Soo [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Seoul (Korea, Republic of); Sungkyunkwan University School of Medicine, Department of Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Shin, Myung-Hee; Cho, Yun Yung [Sungkyunkwan University School of Medicine, Department of Social and Preventive Medicine, Seoul (Korea, Republic of); Choi, Yoon-Ho [Sungkyunkwan University School of Medicine, Center for Health Promotion, Seoul (Korea, Republic of); Kwon, O. Jung [Sungkyunkwan University School of Medicine, Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Seoul (Korea, Republic of); Shin, Kyung Eun [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Seoul (Korea, Republic of); Kyung Hee University Hospital, Department of Diagnostic Radiology, Seoul (Korea, Republic of)

    2015-08-15

    To evaluate the performance of low-dose CT (LDCT) screening for lung cancer (LCA) detection in an Asian population with diverse risks for LCA. LCA screening was performed in 12,427 symptomless Asian subjects using either LDCT (5,771) or chest radiography (CXR) (6,656) in a non-trial setting. Subjects were divided into high-risk and non-high-risk groups. Data were collected on the number of patients with screening-detected LCAs and their survival in order to compare outcomes between LDCT and CXR screening with the stratification of risks considering age, sex and smoking status. In the non-high-risk group, a significant difference was observed for the detection of lung cancer (adjusted OR, 5.07; 95 % CI, 2.72-9.45) and survival (adjusted HR of LCA survival between LDCT vs. CXR group, 0.08; 95 % CI, 0.01-0.62). No difference in detection or survival of LCA was noticed in the high-risk group. LCAs in the non-high-risk group were predominantly adenocarcinomas (96 %), and more likely to be part-solid or non-solid compared with those in the high-risk group (p = 0.023). In the non-high-risk group, LDCT helps detect more LCAs and offers better survival than CXR screening, due to better detection of part solid or non-solid lung adenocarcinomas. (orig.)

  2. Osteoporosis markers on low-dose lung cancer screening chest computed tomography scans predict all-cause mortality

    Energy Technology Data Exchange (ETDEWEB)

    Buckens, C.F. [University Medical Center Utrecht, Radiology Department, Utrecht (Netherlands); University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht (Netherlands); Graaf, Y. van der [University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht (Netherlands); Verkooijen, H.M.; Mali, W.P.; Jong, P.A. de [University Medical Center Utrecht, Radiology Department, Utrecht (Netherlands); Isgum, I.; Mol, C.P. [University Medical Center Utrecht, Image Sciences Institute, Utrecht (Netherlands); Verhaar, H.J. [University Medical Center Utrecht, Department of Geriatric Medicine, Utrecht (Netherlands); Vliegenthart, R.; Oudkerk, M. [Medical Center Groningen, Department of Radiology, Utrecht (Netherlands); Aalst, C.M. van; Koning, H.J. de [Erasmus MC Rotterdam, Department of Public Health, Rotterdam (Netherlands)

    2015-01-15

    Further survival benefits may be gained from low-dose chest computed tomography (CT) by assessing vertebral fractures and bone density. We sought to assess the association between CT-measured vertebral fractures and bone density with all-cause mortality in lung cancer screening participants. Following a case-cohort design, lung cancer screening trial participants (N = 3,673) who died (N = 196) during a median follow-up of 6 years (inter-quartile range: 5.7-6.3) were identified and added to a random sample of N = 383 from the trial. We assessed vertebral fractures using Genant and acute;s semiquantative method on sagittal reconstructions and measured bone density (Hounsfield Units (HU)) in vertebrae. Cox proportional hazards modelling was used to determine if vertebral fractures or bone density were independently predictive of mortality. The prevalence of vertebral fractures was 35 % (95 % confidence interval 30-40 %) among survivors and 51 % (44-58 %) amongst cases. After adjusting for age, gender, smoking status, pack years smoked, coronary and aortic calcium volume and pulmonary emphysema, the adjusted hazard ratio (HR) for vertebral fracture was 2.04 (1.43-2.92). For each 10 HU decline in trabecular bone density, the adjusted HR was 1.08 (1.02-1.15). Vertebral fractures and bone density are independently associated with all-cause mortality. (orig.)

  3. Low dose gemcitabine-loaded lipid nanocapsules target monocytic myeloid-derived suppressor cells and potentiate cancer immunotherapy.

    Science.gov (United States)

    Sasso, Maria Stella; Lollo, Giovanna; Pitorre, Marion; Solito, Samantha; Pinton, Laura; Valpione, Sara; Bastiat, Guillaume; Mandruzzato, Susanna; Bronte, Vincenzo; Marigo, Ilaria; Benoit, Jean-Pierre

    2016-07-01

    Tumor-induced expansion of myeloid-derived suppressor cells (MDSCs) is known to impair the efficacy of cancer immunotherapy. Among pharmacological approaches for MDSC modulation, chemotherapy with selected drugs has a considerable interest due to the possibility of a rapid translation to the clinic. However, such approach is poorly selective and may be associated with dose-dependent toxicities. In the present study, we showed that lipid nanocapsules (LNCs) loaded with a lauroyl-modified form of gemcitabine (GemC12) efficiently target the monocytic (M-) MDSC subset. Subcutaneous administration of GemC12-loaded LNCs reduced the percentage of spleen and tumor-infiltrating M-MDSCs in lymphoma and melanoma-bearing mice, with enhanced efficacy when compared to free gemcitabine. Consistently, fluorochrome-labeled LNCs were preferentially uptaken by monocytic cells rather than by other immune cells, in both tumor-bearing mice and human blood samples from healthy donors and melanoma patients. Very low dose administration of GemC12-loaded LNCs attenuated tumor-associated immunosuppression and increased the efficacy of adoptive T cell therapy. Overall, our results show that GemC12-LNCs have monocyte-targeting properties that can be useful for immunomodulatory purposes, and unveil new possibilities for the exploitation of nanoparticulate drug formulations in cancer immunotherapy.

  4. Low dose decitabine treatment induces CD80 expression in cancer cells and stimulates tumor specific cytotoxic T lymphocyte responses.

    Directory of Open Access Journals (Sweden)

    Li-Xin Wang

    Full Text Available Lack of immunogenicity of cancer cells has been considered a major reason for their failure in induction of a tumor specific T cell response. In this paper, we present evidence that decitabine (DAC, a DNA methylation inhibitor that is currently used for the treatment of myelodysplastic syndrome (MDS, acute myeloid leukemia (AML and other malignant neoplasms, is capable of eliciting an anti-tumor cytotoxic T lymphocyte (CTL response in mouse EL4 tumor model. C57BL/6 mice with established EL4 tumors were treated with DAC (1.0 mg/kg body weight once daily for 5 days. We found that DAC treatment resulted in infiltration of IFN-γ producing T lymphocytes into tumors and caused tumor rejection. Depletion of CD8(+, but not CD4(+ T cells resumed tumor growth. DAC-induced CTL response appeared to be elicited by the induction of CD80 expression on tumor cells. Epigenetic evidence suggests that DAC induces CD80 expression in EL4 cells via demethylation of CpG dinucleotide sites in the promoter of CD80 gene. In addition, we also showed that a transient, low-dose DAC treatment can induce CD80 gene expression in a variety of human cancer cells. This study provides the first evidence that epigenetic modulation can induce the expression of a major T cell co-stimulatory molecule on cancer cells, which can overcome immune tolerance, and induce an efficient anti-tumor CTL response. The results have important implications in designing DAC-based cancer immunotherapy.

  5. Effect of low dose irradiation on estrogen receptor level in MCF-7 breast cancer cells.

    Science.gov (United States)

    Devriendt, D; Ma, Y; Kinnaert, E; Journe, F; Seo, H S; Van Houtte, P; Leclercq, G

    2001-02-20

    Exposure of MCF-7 cells to single and/or repeated low gamma-ray doses (0.5 to 8 Gy) resulted in a decrease in the capacity of these cells to concentrate tritiated estradiol ([3H]E2) (reduction of the number of binding sites). The decrease in the [3H]E2-binding capacity was higher than the survival rate, indicating that it could not be ascribed to cell death. Moreover, such low irradiation doses failed to similarly affect the specific incorporation of [3H]ORG 2058, even when the progesterone receptor was induced by E2, a finding that rejects the hypothesis of a nonspecific effect on all steroid hormone receptors. This loss of [3H]E2 binding was reflected by the elimination of the estrogen receptor alpha (ER) when the latter was assessed by immunocytochemistry. However, additional immunochemical studies (Western blot data) performed on cell extracts under denaturing conditions failed to show any similar elimination of the ER peptide, suggesting that the loss of E2-binding capacity would be relevant to subtle changes in the ER structure and/or ER-associated proteins. The loss of binding capacity, produced by a 3-Gy irradiation, failed to decrease the sensitivity of the cells to E2, since progesterone receptor induction and growth stimulation were maintained. Insufficient ER diminution may explain this observation. PMID:11241328

  6. Smoking cessation interventions within the context of Low-Dose Computed Tomography lung cancer screening: A systematic review.

    Science.gov (United States)

    Piñeiro, Bárbara; Simmons, Vani N; Palmer, Amanda M; Correa, John B; Brandon, Thomas H

    2016-08-01

    The integration of smoking cessation interventions (SCIs) within the context of lung cancer screening programs is strongly recommended by screening guidelines, and is a requirement for Medicare coverage of screening in the US. In Europe, there are no lung cancer screening guidelines, however, research trials are ongoing, and prominent professional societies have begun to recommend lung cancer screening. Little is known about the types and efficacy of SCIs among patients receiving low-dose computed tomography (LDCT) screening. This review addresses this gap. Based on a systematic search, we identified six empirical studies published prior to July 1, 2015, that met inclusion criteria for our review: English language, SCI for LDCT patients, and reported smoking-related outcomes. Three randomized studies and three single-arm studies were identified. Two randomized controlled trials (RCTs) evaluated self-help SCIs, whereas one pilot RCT evaluated the timing (before or after the LDCT scan) of a combined (counseling and pharmacotherapy) SCI. Among the single-arm trials, two observational studies evaluated the efficacy of combined SCI, and one retrospectively assessed the efficacy of clinician-delivered smoking assessment, advice, and assistance. Given the limited research to date, and particularly the lack of studies reporting results from RCTs, assumptions that SCIs would be effective among this population should be made with caution. Findings from this review suggest that participation in a lung screening trial promotes smoking cessation and may represent a teachable moment to quit smoking. Findings also suggest that providers can take advantage of this potentially teachable moment, and that SCIs have been successfully implemented in screening settings. Continued systematic and methodologically sound research in this area will help improve the knowledge base and implementation of interventions for this population of smokers at risk for chronic disease. PMID:27393513

  7. Dose response relationship for unstable-type chromosome aberration rate of spleen cells from mice continuously exposed to low-dose-rate gamma-rays

    International Nuclear Information System (INIS)

    It has been reported that people who are chronically exposed to radiation such as nuclear facility workers and medical radiologists have slightly higher incidences of chromosome aberrations than non-exposed people. However, chronological changes of chromosome aberration rates related to accumulated doses and dose-rates for low dose-rate radiation exposures have not been well studied. Precise analyses of human populations are quite limited because confounding factors influence the results. For this reason, animal experiments are important for analyses. Mice were continuously exposed to gamma-rays at 400 mGy/22 hr/day for 10 days, 20 mGy/22 hr/day for about 400 days, and 1 mGy/22 hr/day for about 615 days under SPF conditions. Chronological changes of unstable-type chromosome aberration rates of spleen cells were observed along with accumulated doses at the middle dose rate and the two low-dose rates by conventional Giemsa-staining method. Aberrations such as dicentric chromosome, ring chromosome and fragment increased in a two-phase manner within 0-1.2 Gy and 2-8 Gy at 20 mGy/22 hr/day. They slightly increased up to 0.5 Gy at 1 mGy/22 hr/day. Aberration rates for 1, 2, 8 Gy at the 20 mGy/22 hr/day and for 0.5 Gy at 1 mGy/22 hr/day were 5.1, 9.6, 13.9 and 2.2 times higher than those of age-matched, non-irradiated control mice, respectively. Chromosome aberration rates at 400 mGy/22 hr/day were 2.7 times higher than that of 20 mGy/22 hr/day for the same total dose of 1.2 Gy. The results that unstable-type chromosome aberrations increased with accumulated dose of the low-dose rate radiation will be important to establish biological dosimetry for people who are chronically exposed to radiation. (author)

  8. Accelerated Partial Breast Irradiation With Low-Dose-Rate Interstitial Implant Brachytherapy After Wide Local Excision: 12-Year Outcomes From a Prospective Trial

    Energy Technology Data Exchange (ETDEWEB)

    Hattangadi, Jona A. [Harvard Radiation Oncology Program, Boston, MA (United States); Powell, Simon N. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); MacDonald, Shannon M.; Mauceri, Thomas; Ancukiewicz, Marek [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Freer, Phoebe [Department of Radiology, Massachusetts General Hospital, Boston, MA (United States); Lawenda, Brian [21st Century Oncology, Las Vegas, NV (United States); Alm El-Din, Mohamed A. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Department of Clinical Oncology, Tanta University Hospital, Tanta (Egypt); Gadd, Michele A.; Smith, Barbara L. [Department of Surgical Oncology, Massachusetts General Hospital, Boston, MA (United States); Taghian, Alphonse G., E-mail: ataghian@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States)

    2012-07-01

    Purpose: To evaluate the long-term toxicity, cosmesis, and local control of accelerated partial breast irradiation with implant brachytherapy after wide local excision for Stage T1N0 breast cancer (BCa). Materials and Methods: Between 1997 and 2001, 50 patients with Stage T1N0M0 BCa were treated in a Phase I-II protocol using low-dose-rate accelerated partial breast irradiation with implant brachytherapy after wide local excision and lymph node surgery. The total dose was escalated in three groups: 50 Gy (n = 20), 55 Gy (n = 17), and 60 Gy (n = 13). Patient- and physician-assessed breast cosmesis, patient satisfaction, toxicity, mammographic abnormalities, repeat biopsies, and disease status were prospectively evaluated at each visit. Kendall's tau ({tau}{sub {beta}}) and logistic regression analyses were used to correlate outcomes with dose, implant volume, patient age, and systemic therapy. Results: The median follow-up period was 11.2 years (range, 4-14). The patient satisfaction rate was 67%, 67% reported good-excellent cosmesis, and 54% had moderate-severe fibrosis. Higher dose was correlated with worse cosmetic outcome ({tau}{sub {beta}} 0.6, p < .0001), lower patient satisfaction ({tau}{sub {beta}} 0.5, p < .001), and worse fibrosis ({tau}{sub {beta}} 0.4, p = .0024). Of the 50 patients, 35% had fat necrosis and 34% developed telangiectasias {>=}1 cm{sup 2}. Grade 3-4 late skin and subcutaneous toxicities were seen in 4 patients (9%) and 6 patients (13%), respectively, and both correlated with higher dose ({tau}{sub {beta}} 0.3-0.5, p {<=} .01). One patient had Grade 4 skin ulceration and fat necrosis requiring surgery. Mammographic abnormalities were seen in 32% of the patients, and 30% underwent repeat biopsy, of which 73% were benign. Six patients had ipsilateral breast recurrence: five elsewhere in the breast, and one at the implant site. One patient died of metastatic BCa after recurrence. The 12-year actuarial local control, recurrence

  9. Accelerated Partial Breast Irradiation With Low-Dose-Rate Interstitial Implant Brachytherapy After Wide Local Excision: 12-Year Outcomes From a Prospective Trial

    International Nuclear Information System (INIS)

    Purpose: To evaluate the long-term toxicity, cosmesis, and local control of accelerated partial breast irradiation with implant brachytherapy after wide local excision for Stage T1N0 breast cancer (BCa). Materials and Methods: Between 1997 and 2001, 50 patients with Stage T1N0M0 BCa were treated in a Phase I-II protocol using low-dose-rate accelerated partial breast irradiation with implant brachytherapy after wide local excision and lymph node surgery. The total dose was escalated in three groups: 50 Gy (n = 20), 55 Gy (n = 17), and 60 Gy (n = 13). Patient- and physician-assessed breast cosmesis, patient satisfaction, toxicity, mammographic abnormalities, repeat biopsies, and disease status were prospectively evaluated at each visit. Kendall’s tau (τβ) and logistic regression analyses were used to correlate outcomes with dose, implant volume, patient age, and systemic therapy. Results: The median follow-up period was 11.2 years (range, 4–14). The patient satisfaction rate was 67%, 67% reported good-excellent cosmesis, and 54% had moderate-severe fibrosis. Higher dose was correlated with worse cosmetic outcome (τβ 0.6, p β 0.5, p β 0.4, p = .0024). Of the 50 patients, 35% had fat necrosis and 34% developed telangiectasias ≥1 cm2. Grade 3–4 late skin and subcutaneous toxicities were seen in 4 patients (9%) and 6 patients (13%), respectively, and both correlated with higher dose (τβ 0.3–0.5, p ≤ .01). One patient had Grade 4 skin ulceration and fat necrosis requiring surgery. Mammographic abnormalities were seen in 32% of the patients, and 30% underwent repeat biopsy, of which 73% were benign. Six patients had ipsilateral breast recurrence: five elsewhere in the breast, and one at the implant site. One patient died of metastatic BCa after recurrence. The 12-year actuarial local control, recurrence-free survival, and overall survival rate was 85% (95% confidence interval, 70–97%), 72% (95% confidence interval, 54–86%), and 87% (95% confidence

  10. Long-term results of low dose daily cisplatin chemotherapy used concurrently with modestly accelerated radiotherapy in locally advanced squamous cell carcinomas of the head neck cancer region

    Directory of Open Access Journals (Sweden)

    Pramod Kumar Gupta

    2014-01-01

    Full Text Available Introduction: Concurrent single agent cisplatin (CDDP with radiotherapy (RT improves outcomes in locally advanced squamous cell carcinomas of the head neck (LA-SCCHN. CDDP at 100 mg/m 2 at 3 weekly intervals raise compliance, hospitalization, and supportive care issues. Low dose daily CDDP was delivered with RT to evaluate its compliance, long-term safety and efficacy. Patients and Methods: During the period of month between November 2005 and May 2007, 52 patients of stage III/IV LA-SCCHN were given with conventional RT in a phased manner (dose-70 Gy/35 fractions/6 weeks along with daily CDDP (6 mg/m 2 ; capped 10 mg-30 cycles over 6 weeks. No hospitalization or antiemetic cover was planned. Compliance, acute and late toxicity were recorded as per Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer grading system and survival outcomes were evaluated. Results : The median follow-up was 63 months. 43 (83% cases complied with RT schedule and >28 cycles of CDDP was administered in 38 (73% cases. Confluent mucositis was seen in 65%, Grade III/IV dysphagia in 67%; 77% required enteral feed and hospitalization in 15%. There were four treatment related deaths. At 5 years, the loco-regional control was 25% (median-11 months and the overall survival was 31% (median-11 months. The 5 years actuarial rates of late Grade III/IV toxicity was 24%. Late swallowing difficulty/aspiration were seen in 17%; xerostomia-40%; ototoxicity-6%; nephrotoxicity-4%; and no second malignancy. Conclusion: Low dose cisplatin with moderately accelerated RT schedule appears feasible and logistically suitable "out-patient" option without increasing long-term toxicity in LA-SCCHN cancer region.

  11. A comparative study of low dose weekly paclitaxel versus cisplatin with concurrent radiation in the treatment of locally advanced head and neck cancers

    Directory of Open Access Journals (Sweden)

    R K Jain

    2009-01-01

    Full Text Available Purpose: The purpose of this study was to compare low dose weekly paclitaxel versus cisplatin with concurrent radiation in locally advanced head and neck cancers. Materials and Methods: From August 2005 to July 2006, a total of 100 biopsy proven, locally advanced head and neck cancers were enrolled for the study. All the patients were stratified in two groups, study group A and control group B. Study group patients received injection Paclitaxel 20 mg/m 2 , I/V 1 hr infusion weekly for 6 weeks and control group patients received injection Cisplatin 30 mg/m 2 , I/V 2 hrs infusion weekly for 6 weeks. All patients received 66-70 Gy concurrent radiation at the rate of 2 Gy/day, 5 #/week, in 6-7 weeks by cobalt theratron phoenix - 80 teletherapy units. Result: Complete response achieved in 73% of patients in study group and 64% of patients in control group. There was no statistically significant difference observed between the study group and the control group (χ2 = 1.167, df = 1, level of significance 0.05. On 3-10 months of follow-up 59% of patients in the study group and 42% of patients in the control group are alive and disease free. Local toxicities including mucositis, dysphasia and skin reactions were more in the study group but tolerable. Conclusion: Efficacy of paclitaxel in low dose weekly schedule is comparable to cisplatin in locally advanced head and neck squamous cell carcinoma. Further analysis and follow-up are needed to evaluate if this benefit will translate into prolonged survival.

  12. Characterization of the neutron irradiation system for use in the Low-Dose-Rate Irradiation Facility at Sandia National Laboratories.

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Manuel,

    2014-08-01

    The objective of this work was to characterize the neutron irradiation system consisting of americium-241 beryllium (241AmBe) neutron sources placed in a polyethylene shielding for use at Sandia National Laboratories (SNL) Low Dose Rate Irradiation Facility (LDRIF). With a total activity of 0.3 TBq (9 Ci), the source consisted of three recycled 241AmBe sources of different activities that had been combined into a single source. The source in its polyethylene shielding will be used in neutron irradiation testing of components. The characterization of the source-shielding system was necessary to evaluate the radiation environment for future experiments. Characterization of the source was also necessary because the documentation for the three component sources and their relative alignment within the Special Form Capsule (SFC) was inadequate. The system consisting of the source and shielding was modeled using Monte Carlo N-Particle transport code (MCNP). The model was validated by benchmarking it against measurements using multiple techniques. To characterize the radiation fields over the full spatial geometry of the irradiation system, it was necessary to use a number of instruments of varying sensitivities. First, the computed photon radiography assisted in determining orientation of the component sources. With the capsule properly oriented inside the shielding, the neutron spectra were measured using a variety of techniques. A N-probe Microspec and a neutron Bubble Dosimeter Spectrometer (BDS) set were used to characterize the neutron spectra/field in several locations. In the third technique, neutron foil activation was used to ascertain the neutron spectra. A high purity germanium (HPGe) detector was used to characterize the photon spectrum. The experimentally measured spectra and the MCNP results compared well. Once the MCNP model was validated to an adequate level of confidence, parametric analyses was performed on the model to optimize for potential

  13. Extended continuous infusion low-dose recombinant interleukin-2 in advanced cancer: prolonged immunomodulation without significant toxicity.

    Science.gov (United States)

    Caligiuri, M A; Murray, C; Soiffer, R J; Klumpp, T R; Seiden, M; Cochran, K; Cameron, C; Ish, C; Buchanan, L; Perillo, D

    1991-12-01

    In previous clinical trials, recombinant interleukin-2 (rIL-2) has been infused at high doses over short periods of time to generate lymphokine-activated killer (LAK) cells in vivo. These trials have been limited by severe toxicities, and the immunologic effects of rIL-2 have been transient. The present study was designed to assess the toxicity and immunologic effects of prolonged administration of low doses of rIL-2. In this phase I study, patients with advanced cancer were scheduled to receive intravenous (IV) infusion of rIL-2 without interruption for 3 months in an outpatient setting. Twenty-one patients received rIL-2 at doses ranging from 0.5 x 10(5) to 6.0 x 10(5) U/m2/d. Treatment was extremely well tolerated, and no patient experienced grade 3 or grade 4 toxicity. The lowest dose level (0.5 x 10(5) U/m2/d) did not have demonstrable immunologic activity. At doses of 1.5 x 10(5) and 4.5 x 10(5) U/m2/d, rIL-2 infusion resulted in the specific expansion of natural-killer (NK) cells (sixfold and ninefold increases, respectively, at these two dose levels) without any changes in B cells, T cells, neutrophils, or monocytes. Grade 2 toxicity was observed at the dose of 6.0 x 10(5) U/m2/d, as three patients required interruption of therapy and two patients who completed therapy developed transient hypothyroidism. In patients with increased NK cells, enhancement of non-major histocompatibility complex (MHC)-restricted cytotoxicity and increased generation of LAK cells in vitro were also demonstrated. Therapy with low-dose rIL-2 can be given safely in an uninterrupted fashion for prolonged periods of time in an outpatient setting. This results in selective expansion of NK cells in vivo with minimal toxicity. Further investigation of this schedule for immunomodulation in vivo should be pursued in phase II studies of both malignant and immunodeficient disease states. PMID:1960552

  14. Fractionated Radioimmunotherapy With 90Y-Clivatuzumab Tetraxetan and Low-Dose Gemcitabine Is Active in Advanced Pancreatic Cancer

    Science.gov (United States)

    Ocean, Allyson J.; Pennington, Kenneth L.; Guarino, Michael J.; Sheikh, Arif; Bekaii-Saab, Tanios; Serafini, Aldo N.; Lee, Daniel; Sung, Max W.; Gulec, Seza A.; Goldsmith, Stanley J.; Manzone, Timothy; Holt, Michael; O’Neil, Bert H.; Hall, Nathan; Montero, Alberto J.; Kauh, John; Gold, David V.; Horne, Heather; Wegener, William A.; Goldenberg, David M.

    2014-01-01

    BACKGROUND It has been demonstrated that the humanized clivatuzumab tetraxetan (hPAM4) antibody targets pancreatic ductal carcinoma selectively. After a trial of radioimmunotherapy that determined the maximum tolerated dose of single-dose yttrium-90-labeled hPAM4 (90Y-hPAM4) and produced objective responses in patients with advanced pancreatic ductal carcinoma, the authors studied fractionated radioimmunotherapy combined with low-dose gemcitabine in this disease. METHODS Thirty-eight previously untreated patients (33 patients with stage IV disease and 5 patients with stage III disease) received gemcitabine 200 mg/m2 weekly for 4 weeks with 90Y-hPAM4 given weekly in Weeks 2, 3, and 4 (cycle 1), and the same cycle was repeated in 13 patients (cycles 2–4). In the first part of the study, 19 patients received escalating weekly 90Y doses of 6.5 mCi/m2, 9.0 mCi/m2, 12.0 mCi/m2, and 15.0 mCi/m2. In the second portion, 19 additional patients received weekly doses of 9.0 mCi/m2 or 12.0 mCi/m2. RESULTS Grade 3/4 thrombocytopenia or neutropenia (according to version 3.0 of the National Cancer Institute’s Common Terminology Criteria for Adverse Events) developed in 28 of 38 patients after cycle 1 and in all retreated patients; no grade >3 nonhematologic toxicities occurred. Fractionated dosing of cycle 1 allowed almost twice the radiation dose compared with single-dose radioimmunotherapy. The maximum tolerated dose of 90Y-hPAM4 was 12.0 mCi/m2 weekly for 3 weeks for cycle 1, with ≤9.0 mCi/m2 weekly for 3 weeks for subsequent cycles, and that dose will be used in future trials. Six patients (16%) had partial responses according to computed tomography-based Response Evaluation Criteria in Solid Tumors, and 16 patients (42%) had stabilization as their best response (58% disease control). The median overall survival was 7.7 months for all 38 patients, including 11.8 months for those who received repeated cycles (46% [6 of 13 patients] ≥1 year), with improved efficacy at

  15. Occurrence and lung cancer probability of new solid nodules at incidence screening with low-dose CT : analysis of data from the randomised, controlled NELSON trial

    NARCIS (Netherlands)

    Walter, Joan E.; Heuvelmans, Marjolein A.; de Jong, Pim A.; Vliegenthart, Rozemarijn; van Ooijen, Peter M. A.; Peters, Robin B.; ten Haaf, Kevin; Yousaf-Khan, Uraujh; van der Aalst, Carlijn M.; de Bock, Geertruida H.; Mali, Willem; Groen, Harry J. M.; de Koning, Harry J.; Oudkerk, Matthijs

    2016-01-01

    Background US guidelines now recommend lung cancer screening with low-dose CT for high-risk individuals. Reports of new nodules after baseline screening have been scarce and are inconsistent because of differences in definitions used. We aimed to identify the occurrence of new solid nodules and thei

  16. Occurrence and lung cancer probability of new solid nodules at incidence screening with low-dose CT : analysis of data from the randomised, controlled NELSON trial

    NARCIS (Netherlands)

    Walter, Joan E.; Heuvelmans, Marjolein A.; de Jong, Pim A.; Vliegenthart, Rozemarijn; van Ooijen, Peter M. A.; Peters, Robin B.; ten Haaf, Kevin; Yousaf-Khan, Uraujh; van der Aalst, Carlijn M.; de Bock, Geertruida H.; Mali, Willem; Groen, Harry J. M.; de Koning, Harry J.; Oudkerk, Matthijs

    2016-01-01

    BACKGROUND: US guidelines now recommend lung cancer screening with low-dose CT for high-risk individuals. Reports of new nodules after baseline screening have been scarce and are inconsistent because of differences in definitions used. We aimed to identify the occurrence of new solid nodules and the

  17. Quality of Life in Hematologic Cancer Patients: A Randomized Clinical Trial of Low Dose Naltrexone Versus Placebo

    Directory of Open Access Journals (Sweden)

    Mohammad A. Seifrabiei

    2008-01-01

    Full Text Available This study aimed to investigate its effect on hematologic cancer patients. This was a randomized controlled trial assessing quality of life in patients with hematologic malignancies from a single institute in Hamedan. Patients were allocated into two study arms and in addition to their routine treatment received either daily naltrexone 3 mg capsules (treatment group or 3 mg starch (placebo group and were followed up for 5 months. Quality of life was measured using the EORTC QLQ-C30 in four points in time (at admission, 1, 3 and 5 months follow-up. Data were analyzed to compare quality of life in two groups. Totally, 89 patients were studied (45 in treatment group and 44 in placebo group. There were no significant differences between two groups either in demographic and clinical characteristics or in baseline quality of life scores. However, at 1 month, 3 and 5-month follow-up assessments significant differences were observed. In one month follow-up two groups were significantly different in social functioning (p<0.05 indicating a better condition in the treatment group. In the 3-month follow-up, social functioning, role functioning, nausea and vomiting and appetite loss were better in the treatment group (all p-values <0.05. In the 5-month follow-up, physical functioning, social functioning, role functioning, global quality of life, nausea and vomiting and appetite loss were significantly better in the nalterxone group. Low dose naltrexone is an effective drug in improving quality of life in patients with hematologic cancers.

  18. SU-E-J-232: Feasibility of MRI-Based Preplan On Low Dose Rate Prostate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Y; Tward, J; Rassiah-Szegedi, P; Zhao, H; Sarkar, V; Huang, L; Szegedi, M; Kokeny, K; Salter, B [University of Utah Huntsman Cancer Institute, Salt Lake City, UT (United States)

    2015-06-15

    Purpose: To investigate the feasibility of using MRI-based preplan for low dose rate prostate brachytherapy. Methods: 12 patients who received transrectal ultrasound (TRUS) guided prostate brachytherapy with Pd-103 were retrospectively studied. Our care-standard of the TRUS-based preplan served as the control. One or more prostate T2-weighted wide and/or narrow-field of view MRIs obtained within the 3 months prior to the implant were imported into the MIM Symphony software v6.3 (MIM Software Inc., Cleveland, OH) for each patient. In total, 37 MRI preplans (10 different image sequences with average thickness of 4.8mm) were generated. The contoured prostate volume and the seed counts required to achieve adequate dosimetric coverage from TRUS and MRI preplans were compared for each patient. The effects of different MRI sequences and image thicknesses were also investigated statistically using Student’s t-test. Lastly, the nomogram from the MRI preplan and TRUS preplan from our historical treatment data were compared. Results: The average prostate volume contoured on the TRUS and MRI were 26.6cc (range: 12.6∼41.3cc), and 27.4 cc (range: 14.3∼50.0cc), respectively. Axial MRI thicknesses (range: 3.5∼8.1mm) did not significantly affect the contoured volume or the number of seeds required on the preplan (R2 = 0.0002 and 0.0012, respectively). Four of the MRI sequences (AX-T2, AX-T2-Whole-Pelvis, AX-T2-FSE, and AXIALT2- Hi-Res) showed statistically significant better prostate volume agreement with TRUS than the other seven sequences (P <0.01). Nomogram overlay between the MRI and TRUS preplans showed good agreement; indicating volumes contoured on MRI preplan scan reliably predict how many seeds are needed for implant. Conclusion: Although MRI does not allow for determination of the actual implant geometry, it can give reliable volumes for seed ordering purposes. Our future work will investigate if MRI is sufficient to reliably replace TRUS preplanning in patients

  19. SU-E-J-232: Feasibility of MRI-Based Preplan On Low Dose Rate Prostate Brachytherapy

    International Nuclear Information System (INIS)

    Purpose: To investigate the feasibility of using MRI-based preplan for low dose rate prostate brachytherapy. Methods: 12 patients who received transrectal ultrasound (TRUS) guided prostate brachytherapy with Pd-103 were retrospectively studied. Our care-standard of the TRUS-based preplan served as the control. One or more prostate T2-weighted wide and/or narrow-field of view MRIs obtained within the 3 months prior to the implant were imported into the MIM Symphony software v6.3 (MIM Software Inc., Cleveland, OH) for each patient. In total, 37 MRI preplans (10 different image sequences with average thickness of 4.8mm) were generated. The contoured prostate volume and the seed counts required to achieve adequate dosimetric coverage from TRUS and MRI preplans were compared for each patient. The effects of different MRI sequences and image thicknesses were also investigated statistically using Student’s t-test. Lastly, the nomogram from the MRI preplan and TRUS preplan from our historical treatment data were compared. Results: The average prostate volume contoured on the TRUS and MRI were 26.6cc (range: 12.6∼41.3cc), and 27.4 cc (range: 14.3∼50.0cc), respectively. Axial MRI thicknesses (range: 3.5∼8.1mm) did not significantly affect the contoured volume or the number of seeds required on the preplan (R2 = 0.0002 and 0.0012, respectively). Four of the MRI sequences (AX-T2, AX-T2-Whole-Pelvis, AX-T2-FSE, and AXIALT2- Hi-Res) showed statistically significant better prostate volume agreement with TRUS than the other seven sequences (P <0.01). Nomogram overlay between the MRI and TRUS preplans showed good agreement; indicating volumes contoured on MRI preplan scan reliably predict how many seeds are needed for implant. Conclusion: Although MRI does not allow for determination of the actual implant geometry, it can give reliable volumes for seed ordering purposes. Our future work will investigate if MRI is sufficient to reliably replace TRUS preplanning in patients

  20. Cancer risk from low dose radiation depends directly on the organ mass in a general model of radiation-induced cancer risk.

    Science.gov (United States)

    Lin, Z W

    2014-04-01

    Current methods of evaluating radiation-induced cancer risk depend on the organ dose but not explicitly on extensive quantities such as the organ mass. However, at the same organ dose, one may expect the larger number of cells in a larger organ to lead to a higher cancer risk. Here the author introduces organ- and radiation type-specific cell cancer risk coefficients and obtains analytical relations between cancer risk and the radiation environment, which contains the dependence of cancer risk on organ masses. The excess cancer risk induced by low dose radiation for an organ is shown to be directly proportional to the organ mass. Therefore the total excess risk for all solid cancers depends directly on organ masses and consequently on body weight or size. This method is also being compared with three existing methods of evaluating the radiation-induced cancer risk, and special cases where this formulation matches each method are demonstrated. The results suggest that the direct dependence of cancer risk on organ masses needs to be checked against existing epidemiological data and, if verified, should be included in the methodology for the evaluation of radiation-induced cancer risk, in particular the individual risk. This dependence is also expected to affect the cancer risk transport from one population group to another that is different in organ mass, body weight or height. PMID:24562066

  1. Low-dose radiation enhances susceptibility to cisplatin in resistant ovarian cancer cells via downregulation of ERCC1 and Bcl-2

    Institute of Scientific and Technical Information of China (English)

    Xiaoran Liu; Donghai Liang; Tao Jiang; Qing Dong; Hongsheng Yu 

    2016-01-01

    Objective Ovarian cancer is one of the leading causes of mortality in patients with malignant gyneco-logical tumors. After surgical intervention for ovarian cancer, cisplatin (DDP)-based chemotherapy is the first-line treatment. However, a major chal enge to treating ovarian cancer is the development of chemore-sistance. Thus, the first aim of this study was to determine whether low-dose radiation could enhance the susceptibility of resistant ovarian cancer cel s to DDP. The second aim was to provide new strategies for treating DDP-resistant ovarian cancer by examining its mechanism. Methods A cel counting kit-8 (CCK8) assay was performed to measure cel proliferation. Flow cytometry was utilized to quantify the apoptosis of DDP-resistant ovarian cancer cel s (SKOV3/DDP) using Annexin V and propidium iodide staining. Real-time quantitative (qPCR) was used to analyze the messenger RNA (mRNA) expression levels of excision repair cross complementing-group 1 (ERCC1) and B-cel lymphoma 2 (Bcl-2) in SKOV3/DDP. Results The IC50 values of the control, conventional-dose, and low-dose groups were 9.367 ± 0.16, 9.289 ± 0.16, and 3.847 ± 0.15, respectively (P Conclusion Low-dose radiation enhanced the sensitivity of resistant ovarian cancer cel s to DDP, pos-sibly by decreasing the DNA repair capacity of tumor cel s and promoting apoptosis.

  2. SU-E-T-501: Normal Tissue Toxicities of Pulsed Low Dose Rate Radiotherapy and Conventional Radiotherapy: An in Vivo Total Body Irradiation Study

    International Nuclear Information System (INIS)

    Purpose: Pulsed low dose rate radiotherapy (PLDR) is a re-irradiation technique for therapy of recurrent cancers. We have previously shown a significant difference in the weight and survival time between the mice treated with conventional radiotherapy (CRT) and PLDR using total body irradiation (TBI). The purpose of this study was to investigate the in vivo effects of PLDR on normal mouse tissues.Materials and Methods: Twenty two male BALB/c nude mice, 4 months of age, were randomly assigned into a PLDR group (n=10), a CRT group (n=10), and a non-irradiated control group (n=2). The Siemens Artiste accelerator with 6 MV photon beams was used. The mice received a total of 18Gy in 3 fractions with a 20day interval. The CRT group received the 6Gy dose continuously at a dose rate of 300 MU/min. The PLDR group was irradiated with 0.2Gyx20 pulses with a 3min interval between the pulses. The mice were weighed thrice weekly and sacrificed 2 weeks after the last treatment. Brain, heart, lung, liver, spleen, gastrointestinal, urinary and reproductive organs, and sternal bone marrow were removed, formalin-fixed, paraffin-embedded and stained with H and E. Morphological changes were observed under a microscope. Results: Histopathological examination revealed atrophy in several irradiated organs. The degree of atrophy was mild to moderate in the PLDR group, but severe in the CRT group. The most pronounced morphological abnormalities were in the immune and hematopoietic systems, namely spleen and bone marrow. Brain hemorrhage was seen in the CRT group, but not in the PLDR group. Conclusions: Our results showed that PLDR induced less toxicity in the normal mouse tissues than conventional radiotherapy for the same dose and regimen. Considering that PLDR produces equivalent tumor control as conventional radiotherapy, it would be a good modality for treatment of recurrent cancers

  3. SU-E-T-501: Normal Tissue Toxicities of Pulsed Low Dose Rate Radiotherapy and Conventional Radiotherapy: An in Vivo Total Body Irradiation Study

    Energy Technology Data Exchange (ETDEWEB)

    Cvetkovic, D; Zhang, P; Wang, B; Chen, L; Ma, C [Fox Chase Cancer Center, Philadelphia, PA (United States)

    2014-06-01

    Purpose: Pulsed low dose rate radiotherapy (PLDR) is a re-irradiation technique for therapy of recurrent cancers. We have previously shown a significant difference in the weight and survival time between the mice treated with conventional radiotherapy (CRT) and PLDR using total body irradiation (TBI). The purpose of this study was to investigate the in vivo effects of PLDR on normal mouse tissues.Materials and Methods: Twenty two male BALB/c nude mice, 4 months of age, were randomly assigned into a PLDR group (n=10), a CRT group (n=10), and a non-irradiated control group (n=2). The Siemens Artiste accelerator with 6 MV photon beams was used. The mice received a total of 18Gy in 3 fractions with a 20day interval. The CRT group received the 6Gy dose continuously at a dose rate of 300 MU/min. The PLDR group was irradiated with 0.2Gyx20 pulses with a 3min interval between the pulses. The mice were weighed thrice weekly and sacrificed 2 weeks after the last treatment. Brain, heart, lung, liver, spleen, gastrointestinal, urinary and reproductive organs, and sternal bone marrow were removed, formalin-fixed, paraffin-embedded and stained with H and E. Morphological changes were observed under a microscope. Results: Histopathological examination revealed atrophy in several irradiated organs. The degree of atrophy was mild to moderate in the PLDR group, but severe in the CRT group. The most pronounced morphological abnormalities were in the immune and hematopoietic systems, namely spleen and bone marrow. Brain hemorrhage was seen in the CRT group, but not in the PLDR group. Conclusions: Our results showed that PLDR induced less toxicity in the normal mouse tissues than conventional radiotherapy for the same dose and regimen. Considering that PLDR produces equivalent tumor control as conventional radiotherapy, it would be a good modality for treatment of recurrent cancers.

  4. Lung cancer incidence and mortality in National Lung Screening Trial participants who underwent low-dose CT prevalence screening: a retrospective cohort analysis of a randomised, multicentre, diagnostic screening trial

    Science.gov (United States)

    Patz, Edward F; Greco, Erin; Gatsonis, Constantine; Pinsky, Paul; Kramer, Barnett S; Aberle, Denise R

    2016-01-01

    Summary Background Annual low-dose CT screening for lung cancer has been recommended for high-risk individuals, but the necessity of yearly low-dose CT in all eligible individuals is uncertain. This study examined rates of lung cancer in National Lung Screening Trial (NLST) participants who had a negative prevalence (initial) low-dose CT screen to explore whether less frequent screening could be justified in some lower-risk subpopulations. Methods We did a retrospective cohort analysis of data from the NLST, a randomised, multicentre screening trial comparing three annual low-dose CT assessments with three annual chest radiographs for the early detection of lung cancer in high-risk, eligible individuals (aged 55–74 years with at least a 30 pack-year history of cigarette smoking, and, if a former smoker, had quit within the past 15 years), recruited from US medical centres between Aug 5, 2002, and April 26, 2004. Participants were followed up for up to 5 years after their last annual screen. For the purposes of this analysis, our cohort consisted of all NLST participants who had received a low-dose CT prevalence (T0) screen. We determined the frequency, stage, histology, study year of diagnosis, and incidence of lung cancer, as well as overall and lung cancer-specific mortality, and whether lung cancers were detected as a result of screening or within 1 year of a negative screen. We also estimated the effect on mortality if the first annual (T1) screen in participants with a negative T0 screen had not been done. The NLST is registered with ClinicalTrials.gov, number NCT00047385. Findings Our cohort consisted of 26 231 participants assigned to the low-dose CT screening group who had undergone their T0 screen. The 19 066 participants with a negative T0 screen had a lower incidence of lung cancer than did all 26 231 T0-screened participants (371·88 [95% CI 337·97–408·26] per 100 000 person-years vs 661·23 [622·07–702·21]) and had lower lung cancer

  5. Estimation of radiation risks at low dose

    International Nuclear Information System (INIS)

    The report presents a review of the effects caused by radiation in low doses, or at low dose rates. For the inheritable (or ''genetic''), as well as for the cancer producing effects of radiation, present evidence is consistent with: (a) a non-linear relationship between the frequency of at least some forms of these effects, with comparing frequencies caused by doses many times those received annually from natural sources, with those caused by lower doses; (b) a probably linear relationship, however, between dose and frequency of effects for dose rates in the region of that received from natural sources, or at several times this rate; (c) no evidence to indicate the existence of a threshold dose below which such effects are not produced, and a strong inference from the mode of action of radiation on cells at low dose rates that no such thresholds are likely to apply to the detrimental, cancer-producing or inheritable, effects resulting from unrepaired damage to single cells. 19 refs

  6. Mammography-oncogenecity at low doses

    International Nuclear Information System (INIS)

    Controversy exists regarding the biological effectiveness of low energy x-rays used for mammography breast screening. Recent radiobiology studies have provided compelling evidence that these low energy x-rays may be 4.42 ± 2.02 times more effective in causing mutational damage than higher energy x-rays. These data include a study involving in vitro irradiation of a human cell line using a mammography x-ray source and a high energy source which matches the spectrum of radiation observed in survivors from the Hiroshima atomic bomb. Current radiation risk estimates rely heavily on data from the atomic bomb survivors, and a direct comparison between the diagnostic energies used in the UK breast screening programme and those used for risk estimates can now be made. Evidence highlighting the increase in relative biological effectiveness (RBE) of mammography x-rays to a range of x-ray energies implies that the risks of radiation-induced breast cancers for mammography x-rays are potentially underestimated by a factor of four. A pooled analysis of three measurements gives a maximal RBE (for malignant transformation of human cells in vitro) of 4.02 ± 0.72 for 29 kVp (peak accelerating voltage) x-rays compared to high energy electrons and higher energy x-rays. For the majority of women in the UK NHS breast screening programme, it is shown that the benefit safely exceeds the risk of possible cancer induction even when this higher biological effectiveness factor is applied. The risk/benefit analysis, however, implies the need for caution for women screened under the age of 50, and particularly for those with a family history (and therefore a likely genetic susceptibility) of breast cancer. In vitro radiobiological data are generally acquired at high doses, and there are different extrapolation mechanisms to the low doses seen clinically. Recent low dose in vitro data have indicated a potential suppressive effect at very low dose rates and doses. Whilst mammography is a low

  7. Metronomic Treatment with Low-Dose Trofosfamide Leads to a Long-Term Remission in a Patient with Docetaxel-Refractory Advanced Metastatic Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Jochen Greiner

    2010-01-01

    Full Text Available The treatment of metastatic prostate cancer patients refractory to androgen withdrawal and docetaxel therapy is currently discouraging and new therapeutic approaches are vastly needed. Here, we report a long-term remission over one year in a 68-year-old patient with metastatic docetaxel-refractory prostate cancer employing low-dose trofosfamide. The patient suffered from distant failure with several bone lesions and lymph node metastases depicted by a (11 C-Choline positron emission tomography/computerized tomography (PET/CT. After initiation of trofosfamide 100 mg taken orally once a day we observed a steadily decreasing PSA value from initial 46.6 down to 2.1 g/l. The Choline-PET/CT was repeated after 10 months of continuous therapy and demonstrated a partial remission of the bone lesions and a regression of all involved lymph nodes but one. Taken together we found an astonishing and durable activity of the alkylating agent trofosfamide given in a metronomic fashion. We rate the side effects as low and state an excellent therapeutic ratio of this drug in our patient.

  8. Health effects of low doses at low dose rates: dose-response relationship modeling in a cohort of workers of the nuclear industry; Effets sanitaires des faibles doses a faibles debits de dose: modelisation de la relation dose-reponse dans une cohorte de travailleurs du nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Metz-Flamant, Camille

    2011-09-19

    The aim of this thesis is to contribute to a better understanding of the health effects of chronic external low doses of ionising radiation. This work is based on the French cohort of CEA-AREVA NC nuclear workers. The mains stages of this thesis were (1) conducting a review of epidemiological studies on nuclear workers, (2) completing the database and performing a descriptive analysis of the cohort, (3) quantifying risk by different statistical methods and (4) modelling the exposure-time-risk relationship. The cohort includes monitored workers employed more than one year between 1950 and 1994 at CEA or AREVA NC companies. Individual annual external exposure, history of work, vital status and causes of death were reconstructed for each worker. Standardized mortality ratios using French national mortality rates as external reference were computed. Exposure-risk analysis was conducted in the cohort using the linear excess relative risk model, based on both Poisson regression and Cox model. Time dependent modifying factors were investigated by adding an interaction term in the model or by using exposure time windows. The cohort includes 36, 769 workers, followed-up until age 60 in average. During the 1968- 2004 period, 5, 443 deaths, 2, 213 cancers, 62 leukemia and 1, 314 cardiovascular diseases were recorded. Among the 57% exposed workers, the mean cumulative dose was 21.5 milli-sieverts (mSv). A strong Healthy Worker Effect is observed in the cohort. Significant elevated risks of pleura cancer and melanoma deaths were observed in the cohort but not associated with dose. No significant association was observed with solid cancers, lung cancer and cardiovascular diseases. A significant dose-response relationship was observed for leukemia excluding chronic lymphatic leukemia, mainly for doses received less than 15 years before and for yearly dose rates higher than 10 mSv. This PhD work contributes to the evaluation of risks associated to chronic external radiation

  9. Differences in the level of DNA double-strand breaks in human tumour cell lines following low dose-rate irradiation

    International Nuclear Information System (INIS)

    In this study, levels of double-strand breaks (DSB) were measured by neutral filter elution under conditions of both repair inhibition and maximum recovery and compared with clonogenic survival curves for high (HDR) and low dose-rate (LDR) irradiation in human carcinoma lines of differing radiosensitivity. Data suggest that whatever the determinant, whether the degree of damage induction or repair, the level of DSB after LDR correlates well with cellular sensitivity in these four cell lines. Thus, DNA damage studies after low dose-rate irradiation may not only enable the examination of irreparable lesions which are important in cell killing but they may also provide a useful predictive test of cellular radiosensitivity. (Author)

  10. Low-Dose Radiation Induces Cell Proliferation in Human Embryonic Lung Fibroblasts but not in Lung Cancer Cells

    Directory of Open Access Journals (Sweden)

    Xinyue Liang

    2016-01-01

    Full Text Available Hormesis and adaptive responses are 2 important biological effects of low-dose ionizing radiation (LDR. In normal tissue, LDR induces hormesis as evinced by increased cell proliferation; however, whether LDR also increases tumor cell proliferation needs to be investigated. In this study, cell proliferation was assayed by total cell numbers and the Cell Counting Kit 8 assay. Mitogen-activated protein kinases (MAPK/extracellular signal-regulated kinase (ERK and phosphatidylinositol 3′ -kinase(PI3K-Akt (PI3K/AKT phosphorylation were determined by Western blot analysis. Human embryonic lung fibroblast 2BS and lung cancer NCI-H446 cell lines were irradiated with LDR at different doses (20-100 mGy. In response to 20 to 75 mGy X-rays, cell proliferation was significantly increased in 2BS but not in NCI-H446 cells. In 2BS cells, LDR at 20 to 75 mGy also stimulated phosphorylation of MAPK/ERK pathway proteins including ERK, MEK, and Raf and of the PI3K/AKT pathway protein AKT. To test whether ERK1/2 and AKT pathway activation was involved in the stimulation of cell proliferation in 2BS cells, the MAPK/ERK and PI3K/AKT pathways were inhibited using their specific inhibitors, U0126 and LY294002. U0126 decreased the phosphorylation of ERK1/2, and LY294002 decreased the phosphorylation of AKT; each could significantly inhibit LDR-induced 2BS cell proliferation. However, LDR did not stimulate these kinases, and kinase inhibitors also did not affect cell proliferation in the NCI-H446 cells. These results suggest that LDR stimulates cell proliferation via the activation of both MAPK/ERK and PI3K/AKT signaling pathways in 2BS but not in NCI-H446 cells. This finding implies the potential for applying LDR to protect normal tissues from radiotherapy without diminishing the efficacy of tumor therapy.

  11. Phase I-II study of everolimus and low-dose oral cyclophosphamide in patients with metastatic renal cell cancer

    International Nuclear Information System (INIS)

    For patients with metastatic renal cell cancer (mRCC) who progressed on vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitor therapy, the orally administered mammalian target of rapamycin (mTOR) inhibitor everolimus has been shown to prolong progression free survival. Intriguingly, inhibition of mTOR also promotes expansion of immunosuppressive regulatory T cells (Tregs) that can inhibit anti-tumor immune responses in a clinically relevant way in various tumor types including RCC. This study intends to investigate whether the antitumor efficacy of everolimus can be increased by preventing the detrimental everolimus induced expansion of Tregs using a metronomic schedule of cyclophosphamide. This phase I-II trial is a national multi-center study of different doses and schedules of low-dose oral cyclophosphamide in combination with a fixed dose of everolimus in patients with mRCC not amenable to or progressive after a VEGF-receptor tyrosine kinase inhibitor containing treatment regimen. In the phase I part of the study the optimal Treg-depleting dose and schedule of metronomic oral cyclophosphamide when given in combination with everolimus will be determined. In the phase II part of the study we will evaluate whether the percentage of patients progression free at 4 months of everolimus treatment can be increased from 50% to 70% by adding metronomic cyclophosphamide (in the dose and schedule determined in the phase I part). In addition to efficacy, we will perform extensive immune monitoring with a focus on the number, phenotype and function of Tregs, evaluate the safety and feasibility of the combination of everolimus and cyclophosphamide, perform monitoring of selected angiogenesis parameters and analyze everolimus and cyclophosphamide drug levels. This phase I-II study is designed to determine whether metronomic cyclophosphamide can be used to counter the mTOR inhibitor everolimus induced Treg expansion in patients with metastatic renal cell

  12. Impact of learning curve and technical changes on dosimetry in low-dose brachytherapy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Le Fur, E. [CHU Brest (France). Radiation Therapy Dept.; Universite de Bretagne Occidentale, Brest (France). Faculte de Medecine et des Sciences de la Sante; Malhaire, J.P.; Baverez, D.; Schlurmann, F. [CHU Brest (France). Radiation Therapy Dept.; Delage, F.; Perrouin-Verbe, M.A. [CHU Brest (France). Urology Dept.; Guerif, S. [University Hospital La Miletrie, Poitiers (France). Radiation Therapy Dept.; Poitiers Univ. (France); Fournier, G.; Valeri, A. [CHU Brest (France). Urology Dept.; Universite de Bretagne Occidentale, Brest (France). Faculte de Medecine et des Sciences de la Sante; Universite Europeenne de Bretagne, Rennes (France); APHP, Hopital Tenon, Paris (France). CeRe.PP; Pradier, O. [CHU Brest (France). Radiation Therapy Dept.; Universite de Bretagne Occidentale, Brest (France). Faculte de Medecine et des Sciences de la Sante; Universite Europeenne de Bretagne, Rennes (France); CHU Brest (France). LaTIM, INSERM U650

    2012-12-15

    Purpose: To assess the impact of experience and technical changes on peri- and postimplantation (1 month later) dosimetry for permanent prostate brachytherapy (PPB). Patients and methods: From July 2003 to May 2010, 150 prostate cancer patients underwent low-dose, loose-seed I{sup 125} PPB as monotherapy with intraoperative planning. Patients were divided into three groups - P1 (n = 64), P2 (n = 45), P3 (n = 41) - according to the technical changes that occurred during the study period: use of an automatic stepper at the beginning of P2 and a high-frequency ultrasound probe in P3. Peri- and postimplantation dosimetric parameters (on day 30) were reported: D90 (dose received by 90% of prostate volume), V100 and V150 (prostate volume receiving, respectively, 100% and 150% of the prescribed dose), D2 cc and D0.1 cc (doses received by 2 cc and 0.1 cc of the rectum), R100 (rectum volume that received 100% of the prescribed dose), and D10 and D30 (doses received by 10% and 30% of the urethra, only during peri-implantation). Results: We observed a decrease in the number of needles and seeds used over time. The mean peri-implantation D90 was 187.52 Gy without a significant difference between the three periods (p = 0.48). The postimplantation D90, V100, and V150 parameters were, respectively, 168.3 Gy, 91.9%, and 55% with no significant difference between the three periods. The peri-implantation and postimplantation D0.1 cc and R100 significantly decreased over time; on day 30: D0.1 cc P1 = 223.1 Gy vs. D0.1 cc P3 = 190.4 Gy (p = 8.10- 5) and R100 P1 = 1.06 cc vs. R100 P3 = 0.53 cc (p = 0.0008). Conclusion: We observed a learning curve for the implantation parameters, which led to a significant decrease in the rectal doses without having any impact on the prostate dosimetric parameters. (orig.)

  13. Low Dose Hyper-radiosensitivity in Human Lung Cancer Cell Line A549 and Its Possible Mechanisms

    Institute of Scientific and Technical Information of China (English)

    Xiaofang DAI; Dan TAO; Hongge WU; Jing CHENG

    2009-01-01

    The low dose hyper-radiosensitivity (HRS) in human lung cancer cell line A549 was in-vestigated,the changes of ATM kinase,cell cycle and apoptosis of cells at different doses of radiation were observed,and the possible mechanisms were discussed.A549 cells in logarithmic growth phase were irradiated with 60Co γ-rays at doses of 0-2 Gy.Together with flow cytometry for precise cell sorting,cell survival fraction was measured by means of conventional colony-formation assay.The expression of ATM1981Ser-P protein was examined by Western blot 1 h after radiation.Apoptosis was detected by Hoechst 33258 fluorescent staining,and Annexin V-FITC/PI staining flow cytometry 24 h after radiation.Cell cycle distribution was observed by flow cytometly 6,12 and 24 h after ra-diation.The results showed that the expression of ATM1981Ser-P protein was observed at 0.2 Gy,followed by an increase at >0.2 Gy,and reached the peak at 0.5 Gy,with little further increase as the dose exceeded 0.5 Gy.Twenty-four h after radiation,partial cells presented the characteristic mor-phological changes of apoptosis,and the cell apoptosis curve was coincident with the survival curve.As compared with control group,the cell cycle almost had no changes after exposure to 0.1 and 0.2 Gy radiation (P>0.05).After exposure to 0.3,0.4 and 0.5 Cry radiation,G2/M phase arrest occurred 6 and 12 h after radiation (P<0.05),and the ratio of G2/M phase cells was decreased 24 h after radiation (P<0.05).It was concluded that A549 cells displayed the phenomenon of HRS/IRR.The mode of cell death was mainly apoptosis.The activity of ATM and cell cycle change may take an important role in HRS/IRR.

  14. Impact of learning curve and technical changes on dosimetry in low-dose brachytherapy for prostate cancer

    International Nuclear Information System (INIS)

    Purpose: To assess the impact of experience and technical changes on peri- and postimplantation (1 month later) dosimetry for permanent prostate brachytherapy (PPB). Patients and methods: From July 2003 to May 2010, 150 prostate cancer patients underwent low-dose, loose-seed I125 PPB as monotherapy with intraoperative planning. Patients were divided into three groups - P1 (n = 64), P2 (n = 45), P3 (n = 41) - according to the technical changes that occurred during the study period: use of an automatic stepper at the beginning of P2 and a high-frequency ultrasound probe in P3. Peri- and postimplantation dosimetric parameters (on day 30) were reported: D90 (dose received by 90% of prostate volume), V100 and V150 (prostate volume receiving, respectively, 100% and 150% of the prescribed dose), D2 cc and D0.1 cc (doses received by 2 cc and 0.1 cc of the rectum), R100 (rectum volume that received 100% of the prescribed dose), and D10 and D30 (doses received by 10% and 30% of the urethra, only during peri-implantation). Results: We observed a decrease in the number of needles and seeds used over time. The mean peri-implantation D90 was 187.52 Gy without a significant difference between the three periods (p = 0.48). The postimplantation D90, V100, and V150 parameters were, respectively, 168.3 Gy, 91.9%, and 55% with no significant difference between the three periods. The peri-implantation and postimplantation D0.1 cc and R100 significantly decreased over time; on day 30: D0.1 cc P1 = 223.1 Gy vs. D0.1 cc P3 = 190.4 Gy (p = 8.10- 5) and R100 P1 = 1.06 cc vs. R100 P3 = 0.53 cc (p = 0.0008). Conclusion: We observed a learning curve for the implantation parameters, which led to a significant decrease in the rectal doses without having any impact on the prostate dosimetric parameters. (orig.)

  15. The feasibility and safety of high-intensity focused ultrasound combined with low-dose external beam radiotherapy as supplemental therapy for advanced prostate cancer following hormonal therapy

    OpenAIRE

    Wu, Rui-Yi; Wang, Guo-Min; Xu, Lei; ZHANG, BO-HENG; Xu, Ye-Qing; Zeng, Zhao-Chong; Chen, Bing

    2011-01-01

    The aim of this study was to investigate the feasibility and safety of high-intensity focused ultrasound (HIFU) combined with (+) low-dose external beam radiotherapy (LRT) as supplemental therapy for advanced prostate cancer (PCa) following hormonal therapy (HT). Our definition of HIFU+LRT refers to treating primary tumour lesions with HIFU in place of reduced field boost irradiation to the prostate, while retaining four-field box irradiation to the pelvis in conventional-dose external beam r...

  16. TH-C-12A-07: Implementation of a Pulsed Low Dose Date Radiotherapy (PLRT) Protocol for Recurrent Cancers Using Advanced Beam Delivery

    Energy Technology Data Exchange (ETDEWEB)

    Ma, C; Lin, M; Chen, L; Price, R [Fox Chase Cancer Center, Philadelphia, PA (United States); Li, J; Kang, S; Wang, P; Lang, J [Sichuan Provincial Cancer Hospital, Chengdu (China)

    2014-06-15

    Purpose: Recent in vitro and in vivo experimental findings provided strong evidence that pulsed low-dose-rate radiotherapy (PLDR) produced equivalent tumor control as conventional radiotherapy with significantly reduced normal tissue toxicities. This work aimed to implement a PLDR clinical protocol for the management of recurrent cancers utilizing IMRT and VMAT. Methods: Our PLDR protocol requires that the daily 2Gy dose be delivered in 0.2Gy×10 pulses with a 3min interval between the pulses. To take advantage of low-dose hyper-radiosensitivity the mean dose to the target is set at 0.2Gy and the maximum dose is limited to 0.4Gy per pulse. Practical planning strategies were developed for IMRT and VMAT: (1) set 10 ports for IMRT and 10 arcs for VMAT with each angle/arc as a pulse; (2) set the mean dose (0.2Gy) and maximum dose (0.4Gy) to the target per pulse as hard constraints (no constraints to OARs); (3) select optimal port/arc angles to avoid OARs; and (4) use reference structures in or around target/OARs to reduce maximum dose to the target/OARs. IMRT, VMAT and 3DCRT plans were generated for 60 H and N, breast, lung, pancreas and prostate patients and compared. Results: All PLDR treatment plans using IMRT and VMAT met the dosimetry requirements of the PLDR protocol (mean target dose: 0.20Gy±0.01Gy; maximum target dose < 0.4Gy). In comparison with 3DCRT, IMRT and VMAT exhibited improved target dose conformity and OAR dose sparing. A single arc can minimize the difference in the target dose due to multi-angle incidence although the delivery time is longer than 3DCRT and IMRT. Conclusion: IMRT and VMAT are better modalities for PLDR treatment of recurrent cancers with superior target dose conformity and critical structure sparing. The planning strategies/guidelines developed in this work are practical for IMRT/VMAT treatment planning to meet the dosimetry requirements of the PLDR protocol.

  17. Frequency of chromosome aberration and dose/dose rate effects in the mouse exposed to long-term low dose radiation

    International Nuclear Information System (INIS)

    Authors have been conducting long term irradiation experiments in the mouse with the dose rate as low as unreported hitherto and have shown with highly sensitive methods to detect chromosomal aberration, that there is the positive dose rate effect under even such a condition, of which details are described herein. According to the definition of United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCER) (1993), the low dose rate is 137Cs-gamma-ray at the low dose rate of 1 or 20 mGy/22 h/day (total, 125-615 or 100-8000 mGy, respectively). Other groups received radiations of 0 Gy (non-irradiated, age-matched control), 200-8000 mGy at 200 mGy/22 h/day, 400-8000 mGy at 400 mGy/22 h/day, or 250-2000 mGy at 890 mGy/min. At the defined days after exposure, mice were sacrificed, their spleens were dissected out, splenic cells were cultured for 48 hr, and their chromosome specimens were prepared to be stained with Giemsa or FISH (fluorescence in situ hybridization). Dicentric (dic) and translocation chromosomal aberrations were found to increase even with the lowest total (accumulated) dose, where the frequency was significantly higher than that in control. Comparison of the regression slopes at each dose rate of the relation between dose and aberration revealed the difference dependent on the rate, thus demonstrating the presence of dose rate effect. Dose/dose rate effect factor (DDREF) calculated by authors' procedure (at 1000-100 mGy: DDREF=17.8-4.5 for dic by FISH; 24.5-5.2 for dic+ring chromosome by Giemsa) was thought important in the risk assessment of low dose radiation and also revealed a problem in International Commission on Radiological Protection (ICRP) (1991) calculation of the factor. (K.T.)

  18. Reliable categorisation of visual scoring of coronary artery calcification on low-dose CT for lung cancer screening: validation with the standard Agatston score

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yi-Luan; Wu, Fu-Zong; Wang, Yen-Chi [Kaohsiung Veterans General Hospital, Department of Radiology, Kaohsiung 813 (China); National Yang Ming University, Faculty of Medicine, School of Medicine, Taipei (China); Ju, Yu-Jeng [National Taiwan University, Department of Psychology, Taipei (China); Mar, Guang-Yuan [Kaohsiung Veterans General Hospital, Division of Cardiology, Department of Medicine, Kaohsiung 813 (China); Chuo, Chiung-Chen [Kaohsiung Veterans General Hospital, Department of Radiology, Kaohsiung 813 (China); Lin, Huey-Shyan [Fooyin University, School of Nursing, Kaohsiung (China); Wu, Ming-Ting [Kaohsiung Veterans General Hospital, Department of Radiology, Kaohsiung 813 (China); National Yang Ming University, Faculty of Medicine, School of Medicine, Taipei (China); National Yang Ming University, Institute of Clinical Medicine, Taipei (China)

    2013-05-15

    To validate the reliability of the visual coronary artery calcification score (VCACS) on low-dose CT (LDCT) for concurrent screening of CAC and lung cancer. We enrolled 401 subjects receiving LDCT for lung cancer screening and ECG-gated CT for the Agatston score (AS). LDCT was reconstructed with 3- and 5-mm slice thickness (LDCT-3mm and LDCT-5mm respectively) for VCACS to obtain VCACS-3mm and VCACS-5mm respectively. After a training session comprising 32 cases, two observers performed four-scale VCACS (absent, mild, moderate, severe) of 369 data sets independently, the results were compared with four-scale AS (0, 1-100, 101-400, >400). CACs were present in 39.6 % (146/369) of subjects. The sensitivity of VCACS-3mm was higher than for VCACS-5mm (83.6 % versus 74.0 %). The median of AS of the 24 false-negative cases in VCACS-3mm was 2.3 (range 1.1-21.1). The false-negative rate for detecting AS {>=} 10 on LDCT-3mm was 1.9 %. VCACS-3mm had higher concordance with AS than VCACS-5mm (k = 0.813 versus k = 0.685). An extended test of VCACS-3mm for four junior observers showed high inter-observer reliability (intra-class correlation = 0.90) and good concordance with AS (k = 0.662-0.747). This study validated the reliability of VCACS on LDCT for lung cancer screening and showed that LDCT-3mm was more feasible than LDCT-5mm for CAD risk stratification. (orig.)

  19. Marked increase in the rate of ocular lens and forelimb regeneration in the newt. Cynops pyrrhogaster, following partial body exposure to low dose X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, T.; Kanao, T.; Miyachi, Y.

    2004-07-01

    In recent years, concern over the stimulating effects of low-dose X-rays has been growing. Therefore the effects of low-dose X-irradiation on lens and forelimb regeneration in the newt were examined. Newts were subjected to s harm or whole-body X-ray exposure at a dose of 0.05, 0.2 or 0.4Gy, delivered at a rate of 0.43Gy/min. The eyeballs were fixed in formalin solution, embedded in paraffin and assessed histologically. On day 14 after lens removal, unexposed animals showed the formation of a hollow epithelial vesicle of depigmented cells continuous with the laminae of the iris corresponding to the expected regeneration stage (Reyer's regeneration stage II). In contrast, lenses from newts exposed to a 0.2Gy dose X-ray showed some formation of the primary lens fiber nucleus corresponding to the fiber differentiation stage (Reyer's regeneration stage III-early). Thus, low-dose X-irradiation induced well regeneration compared to the unexposed groups. However, when newts were injected with N-nitro-L-arginine, nitric oxide inhibitor, no radiation-induced effect could be observed. Furthermore, an acceleration from Reyer's stage II to III-early was also found on day 14 following irradiation of only the upper belly, including the spleen. Interestingly, well regeneration could be observed on forelimb stage. On 6 weeks after amputation, unexposed animal was showed the assembly of the condrogenesis of the radius and ulna. In contrast, forelimb from newts exposed to a 0.2Gy spleen portion was showed the onset of digit formation. The effects of low-dose X-irradiation on regeneration may be mediated by changes in immune activity. (Author)

  20. Immunological network activation by low-dose rate irradiation. Analysis of cell populations and cell surface molecules in whole body irradiated mice

    Energy Technology Data Exchange (ETDEWEB)

    Ina, Yasuhiro; Sakai, Kazuo [Central Research Inst. of Electric Power Industry, Low Dose Radiation Research Center, Komae, Tokyo (Japan)

    2003-07-01

    The effects of low-dose rate whole body irradiation on biodefense and immunological systems were investigated using female C57BL/6 (B6) mice. These B6 mice were exposed continuously to {gamma}-rays from a {sup 137}Cs source in the long-term low-dose rate irradiation facility at CRIEPI for 0 - 12 weeks at a dose rate of 0.95 mGy/hr. In the bone marrow, thymus, spleen, lymph nodes, and peripheral blood of the irradiated mice, changes in cell populations and cell surface molecules were examined. The cell surface functional molecules (CD3, CD4, CD8, CD19, CD45R/B220, ICAM-1, Fas, NK-1.1, CXCR4, and CCR5), and activation molecules (THAM, CD28, CD40, CD44H, CD70, B7-1, B7-2, OX-40 antigen, CTLA-4, CD30 ligand, and CD40 ligand) were analyzed by flow cytometry. The percentage of CD4{sup +} T cells and cell surface CD8 molecule expressions on the CD8{sup +} T cells increased significantly to 120-130% after 3 weeks of the irradiation, compared to non-irradiated control mice. On the other hand, the percentage of CD45R/B220{sup +} CD40{sup +} B cells, which is one of the immunological markers of inflammation, infection, tumor, and autoimmune disease, decreased significantly to 80-90% between the 3rd to 5th week of irradiation. There was no significant difference in other cell population rates and cell surface molecule expression. Furthermore, abnormal T cells bearing mutated T cell receptors induced by high-dose rate irradiation were not observed throughout this study. These results suggest that low-dose rate irradiation activates the immunological status of the whole body. (author)

  1. Hearing loss due to concurrent daily low-dose cisplatin chemoradiation for locally advanced head and neck cancer

    International Nuclear Information System (INIS)

    Background and purpose: Cisplatin-based chemo-irradiation (CRT) is increasingly used for head and neck squamous cell carcinoma (HNSCC). We aimed to assess hearing deterioration due to low-dose cisplatin chemoradiation and to compare the observed hearing loss with hearing loss in our previously described high-dose cisplatin CRT cohort. Materials and methods: A prospective analysis of hearing thresholds at low and (ultra)-high frequencies obtained before and after treatment in 60 patients. Patients received low-dose cisplatin (6 mg/m2, daily infusions, 20-25 days) with concomitant accelerated radiotherapy (70 Gy). Results: Audiometry up to 16 kHz was performed before therapy and 31 days (median) post-treatment. The total incidence of ototoxicity in CTCAEv3.0 was 31% in audiograms up to 8 kHz, and 5% of ears tested qualified for HAs due to treatment. The mean hearing loss at speech frequencies was 2.6 dB (SD 5.7) and 2.3 dB (SD 9.2) at PTA 1-2-4 kHz air-conduction and bone-conduction, respectively. The mean hearing loss at ultra-high frequencies (PTA AC 8-10-12.5 kHz) was 9.0 dB (SD 8.1). Low-dose cisplatin CRT caused less acute hearing loss (CTCAE 31%), compared to high-dose cisplatin CRT (CTCAE 78%). Conclusions: Low-dose cisplatin chemo-irradiation for HNSCC is a relatively safe treatment protocol with respect to ototoxicity

  2. Low-dose prednisolone in first-line docetaxel for patients with metastatic castration-resistant prostate cancer

    DEFF Research Database (Denmark)

    Kongsted, Per; Svane, Inge Marie; Lindberg, Henriette;

    2015-01-01

    incidence of peripheral edema (32% vs. 15%, Pfebrile neutropenia in this group (25% vs. 10%, P...% CI: 0.76-1.26, P = 0.89, Cox proportional hazard regression model). CONCLUSIONS: Coadministration of low-dose P reduced the incidence of peripheral edema, grade 3 nonhematological toxicity, and the risk of being admitted owing to febrile neutropenia during treatment with D. Adjusted survival analysis...

  3. Low-Dose Acetylsalicylic Acid in Treating Patients With Stage I-III Non-Small Cell Lung Cancer

    Science.gov (United States)

    2016-06-28

    Adenocarcinoma of the Lung; Recurrent Non-small Cell Lung Cancer; Stage IA Non-small Cell Lung Cancer; Stage IB Non-small Cell Lung Cancer; Stage IIA Non-small Cell Lung Cancer; Stage IIB Non-small Cell Lung Cancer; Stage IIIA Non-small Cell Lung Cancer; Stage IIIB Non-small Cell Lung Cancer

  4. Prostate-Specific Antigen at 4 to 5 Years After Low-Dose-Rate Prostate Brachytherapy Is a Strong Predictor of Disease-Free Survival

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Andrea C. [Department of Radiation Oncology, British Columbia Cancer Agency Vancouver Centre, Vancouver, British Columbia (Canada); Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia (Canada); Morris, W. James, E-mail: JMorris@bccancer.bc.ca [Department of Radiation Oncology, British Columbia Cancer Agency Vancouver Centre, Vancouver, British Columbia (Canada); Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia (Canada); Lapointe, Vincent [Department of Medical Physics, British Columbia Cancer Agency Vancouver Centre, Vancouver, British Columbia (Canada); Hamm, Jeremy [Department of Population Oncology, British Columbia Cancer Agency Vancouver Centre, Vancouver, British Columbia (Canada); Keyes, Mira; Pickles, Tom; McKenzie, Michael [Department of Radiation Oncology, British Columbia Cancer Agency Vancouver Centre, Vancouver, British Columbia (Canada); Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia (Canada); Spadinger, Ingrid [Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia (Canada); Department of Medical Physics, British Columbia Cancer Agency Vancouver Centre, Vancouver, British Columbia (Canada)

    2014-01-01

    Purpose: To determine (1) the prognostic utility of prostate-specific antigen (PSA) concentration at 45 to 60 months (48mPSA) after low-dose-rate prostate brachytherapy (LDR-PB); (2) the predictors of 48mPSA; and (3) the prognostic utility of directional trends between PSA levels at 24, 36, and 48 months after LDR-PB. Methods and Materials: Between 1998 and 2008, 2223 patients with low- and intermediate-risk prostate cancer received LDR-PB monotherapy. A cohort of 1434 of these patients was identified with a documented 48mPSA and no evidence of disease relapse prior to the 48mPSA. In addition, a subset of this cohort (n=585) was identified with ≥72 months of follow-up and documented PSA values at both 24 and 36 months after implantation. Results: Median follow-up time was 76 months. Eight-year Kaplan-Meier disease-free survival (DFS) rates were 100% vs 73.4% for patients with 48mPSA ≤0.2 vs those with >0.2 ng/mL; 99.1% versus 53.8% for a 48mPSA threshold of ≤0.4 versus >0.4 ng/mL, respectively; and 97.3% versus 0% for a threshold of ≤1.0 versus >1.0 ng/mL, respectively. On multivariate analysis, the only factor predictive of DFS was 48mPSA (P<.0001). On subset analysis (n=585), 29 patients had a PSA rise (defined as >0.2 ng/mL) between 24 and 36 months, 24 patients had a rise between 36 and 48 months, and 11 patients had rises over both intervals. Failure rates in these patients were 52%, 79%, and 100%, respectively. On multivariate analysis, initial PSA, androgen deprivation therapy, and dose to 90% of the prostate significantly correlated with 48mPSA but together accounted for only ∼5% of its total variance. Conclusions: The 48mPSA after LDR-PB is highly predictive of long-term DFS. Patients with 48mPSA ≤0.4 ng/mL had a <1% risk of disease relapse at 8 years, whereas all patients with 48mPSA >1.0 ng/mL relapsed. Consecutive PSA rises of >0.2 ng/mL from 24 to 36 months and from 36 to 48 months were also highly predictive of subsequent failure.

  5. Low Dose Suppression of Neoplastic Transformation in Vitro

    Energy Technology Data Exchange (ETDEWEB)

    John Leslie Redpath

    2012-05-01

    This grant was to study the low dose suppression of neoplastic transformation in vitro and the shape of the dose-response curve at low doses and dose-rates of ionizing radiation. Previous findings had indicated a suppression of transformation at dose <10cGy of low-LET radiation when delivered at high dose-rate. The present study indicates that such suppression extends out to doses in excess of 100cGy when the dose (from I-125 photons) is delivered at dose-rates as low as 0.2 mGy/min and out to in excess of {approx}25cGy the highest dose studied at the very low dose-rate of 0.5 mGy/day. We also examined dose-rate effects for high energy protons (which are a low-LET radiation) and suppression was evident below {approx}10cGy for high dose-rate delivery and at least out to 50cGy for low dose-rate (20cGy/h) delivery. Finally, we also examined the effect of low doses of 1 GeV/n iron ions (a high-LET radiation) delivered at high dose-rate on transformation at low doses and found a suppression below {approx}10cGy that could be attributable to an adaptive response in bystander cells induced by the associated low-LET delta rays. These results have implications for cancer risk assessment at low doses.

  6. An evaluation of a Low-Dose-Rate (LDR) brachytherapy procedure using a systems engineering & error analysis methodology for health care (SEABH) - (SAVE)

    LENUS (Irish Health Repository)

    Chadwick, Liam

    2012-03-12

    Health Care Failure Modes and Effects Analysis (HFMEA®) is an established tool for risk assessment in health care. A number of deficiencies have been identified in the method. A new method called Systems and Error Analysis Bundle for Health Care (SEABH) was developed to address these deficiencies. SEABH has been applied to a number of medical processes as part of its validation and testing. One of these, Low Dose Rate (LDR) prostate Brachytherapy is reported in this paper. The case study supported the validity of SEABH with respect to its capacity to address the weaknesses of (HFMEA®).

  7. Differential effects of repeated low dose treatment with the cannabinoid agonist WIN 55,212-2 in experimental models of bone cancer pain and neuropathic pain

    DEFF Research Database (Denmark)

    Hald, Andreas; Ding, Ming; Egerod, Kristoffer Lihme;

    2008-01-01

    Pain due to bone malignancies is one of the most difficult types of cancer pain to fully control and may further decrease the patients' quality of life. Animal models of chronic pain conditions resulting from peripheral inflammatory reactions or nerve injuries are responsive to treatment....... Furthermore, this treatment strategy was not found to induce measurable CNS related side effects or tolerance. Cancer cell viability assays and bone volume fraction assessed by micro computed tomography (microCT) demonstrated that these effects were not due to changes in cancer progression. The difference...... with cannabinoid agonists. However, the use of cannabinoid agonists in humans may be hampered by CNS related side effects and development of tolerance. In the present study, we investigated the effect of repeated low dose administration of the synthetic cannabinoid agonist WIN 55,212-2 on bone cancer pain...

  8. Low-Dose Hyper-Radiosensitivity Is Not a Common Effect in Normal Asynchronous and G2-Phase Fibroblasts of Cancer Patients

    International Nuclear Information System (INIS)

    Purpose: In our previous study, using the micronucleus assay, a low-dose hyper-radiosensitivity (HRS)-like phenomenon was observed for normal fibroblasts of 2 of the 40 cancer patients investigated. In this article we report, for the first time, the survival response of primary fibroblasts from 25 of these patients to low-dose irradiation and answer the question regarding the effect of G2-phase enrichment on HRS elicitation. Methods and Materials: The clonogenic survival of asynchronous as well as G2-phase enriched fibroblast populations was measured. Separation of G2-phase cells and precise cell counting was performed using a fluorescence-activated cell sorter. Sorted and plated cells were irradiated with single doses (0.1-4 Gy) of 6-MV x-rays. For each patient, at least 4 independent experiments were performed, and the induced-repair model was fitted over the whole data set to confirm the presence of HRS effect. Results: The HRS response was demonstrated for the asynchronous and G2-phase enriched cell populations of 4 patients. For the rest of patients, HRS was not defined in either of the 2 fibroblast populations. Thus, G2-phase enrichment had no effect on HRS elicitation. Conclusions: The fact that low-dose hyper-radiosensitivity is not a common effect in normal human fibroblasts implies that HRS may be of little consequence in late-responding connective tissues with regard to radiation fibrosis

  9. Low-Dose Hyper-Radiosensitivity Is Not a Common Effect in Normal Asynchronous and G2-Phase Fibroblasts of Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Słonina, Dorota, E-mail: z5slonin@cyfronet.pl [Department of Applied Radiobiology, Centre of Oncology, Maria-Skłodowska-Curie Memorial Institute Kraków, Kraków (Poland); Biesaga, Beata; Janecka, Anna [Department of Applied Radiobiology, Centre of Oncology, Maria-Skłodowska-Curie Memorial Institute Kraków, Kraków (Poland); Kabat, Damian [Department of Medical Physics, Centre of Oncology, Maria-Skłodowska-Curie Memorial Institute Kraków, Kraków (Poland); Bukowska-Strakova, Karolina [Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, Kraków (Poland); Gasińska, Anna [Department of Applied Radiobiology, Centre of Oncology, Maria-Skłodowska-Curie Memorial Institute Kraków, Kraków (Poland)

    2014-02-01

    Purpose: In our previous study, using the micronucleus assay, a low-dose hyper-radiosensitivity (HRS)-like phenomenon was observed for normal fibroblasts of 2 of the 40 cancer patients investigated. In this article we report, for the first time, the survival response of primary fibroblasts from 25 of these patients to low-dose irradiation and answer the question regarding the effect of G2-phase enrichment on HRS elicitation. Methods and Materials: The clonogenic survival of asynchronous as well as G2-phase enriched fibroblast populations was measured. Separation of G2-phase cells and precise cell counting was performed using a fluorescence-activated cell sorter. Sorted and plated cells were irradiated with single doses (0.1-4 Gy) of 6-MV x-rays. For each patient, at least 4 independent experiments were performed, and the induced-repair model was fitted over the whole data set to confirm the presence of HRS effect. Results: The HRS response was demonstrated for the asynchronous and G2-phase enriched cell populations of 4 patients. For the rest of patients, HRS was not defined in either of the 2 fibroblast populations. Thus, G2-phase enrichment had no effect on HRS elicitation. Conclusions: The fact that low-dose hyper-radiosensitivity is not a common effect in normal human fibroblasts implies that HRS may be of little consequence in late-responding connective tissues with regard to radiation fibrosis.

  10. The investigation of prostatic calcifications using μ-PIXE analysis and their dosimetric effect in low dose rate brachytherapy treatments using Geant4

    Science.gov (United States)

    Pope, D. J.; Cutajar, D. L.; George, S. P.; Guatelli, S.; Bucci, J. A.; Enari, K. E.; Miller, S.; Siegele, R.; Rosenfeld, A. B.

    2015-06-01

    Low dose rate brachytherapy is a widely used modality for the treatment of prostate cancer. Most clinical treatment planning systems currently in use approximate all tissue to water, neglecting the existence of inhomogeneities, such as calcifications. The presence of prostatic calcifications may perturb the dose due to the higher photoelectric effect cross section in comparison to water. This study quantitatively evaluates the effect of prostatic calcifications on the dosimetric outcome of brachytherapy treatments by means of Monte Carlo simulations and its potential clinical consequences. Four pathological calcification samples were characterised with micro-particle induced x-ray emission (μ-PIXE) to determine their heavy elemental composition. Calcium, phosphorus and zinc were found to be the predominant heavy elements in the calcification composition. Four clinical patient brachytherapy treatments were modelled using Geant4 based Monte Carlo simulations, in terms of the distribution of brachytherapy seeds and calcifications in the prostate. Dose reductions were observed to be up to 30% locally to the calcification boundary, calcification size dependent. Single large calcifications and closely placed calculi caused local dose reductions of between 30-60%. Individual calculi smaller than 0.5 mm in diameter showed minimal dosimetric impact, however, the effects of small or diffuse calcifications within the prostatic tissue could not be determined using the methods employed in the study. The simulation study showed a varying reduction on common dosimetric parameters. D90 showed a reduction of 2-5%, regardless of calcification surface area and volume. The parameters V100, V150 and V200 were also reduced by as much as 3% and on average by 1%. These reductions were also found to relate to the surface area and volume of calcifications, which may have a significant dosimetric impact on brachytherapy treatment, however, such impacts depend strongly on specific factors

  11. The investigation of prostatic calcifications using μ-PIXE analysis and their dosimetric effect in low dose rate brachytherapy treatments using Geant4

    International Nuclear Information System (INIS)

    Low dose rate brachytherapy is a widely used modality for the treatment of prostate cancer. Most clinical treatment planning systems currently in use approximate all tissue to water, neglecting the existence of inhomogeneities, such as calcifications. The presence of prostatic calcifications may perturb the dose due to the higher photoelectric effect cross section in comparison to water. This study quantitatively evaluates the effect of prostatic calcifications on the dosimetric outcome of brachytherapy treatments by means of Monte Carlo simulations and its potential clinical consequences.Four pathological calcification samples were characterised with micro-particle induced x-ray emission (μ-PIXE) to determine their heavy elemental composition. Calcium, phosphorus and zinc were found to be the predominant heavy elements in the calcification composition. Four clinical patient brachytherapy treatments were modelled using Geant4 based Monte Carlo simulations, in terms of the distribution of brachytherapy seeds and calcifications in the prostate. Dose reductions were observed to be up to 30% locally to the calcification boundary, calcification size dependent. Single large calcifications and closely placed calculi caused local dose reductions of between 30–60%. Individual calculi smaller than 0.5 mm in diameter showed minimal dosimetric impact, however, the effects of small or diffuse calcifications within the prostatic tissue could not be determined using the methods employed in the study. The simulation study showed a varying reduction on common dosimetric parameters. D90 showed a reduction of 2–5%, regardless of calcification surface area and volume. The parameters V100, V150 and V200 were also reduced by as much as 3% and on average by 1%. These reductions were also found to relate to the surface area and volume of calcifications, which may have a significant dosimetric impact on brachytherapy treatment, however, such impacts depend strongly on specific

  12. Plasma levels of a low-dose constant-rate-infusion of ketamine and its effect on single and repeated nociceptive stimuli in conscious dogs.

    Science.gov (United States)

    Bergadano, Alessandra; Andersen, Ole K; Arendt-Nielsen, Lars; Theurillat, Regula; Thormann, Wolfgang; Spadavecchia, Claudia

    2009-11-01

    This study quantitatively investigated the analgesic action of a low-dose constant-rate-infusion (CRI) of racemic ketamine (as a 0.5 mg kg(-1) bolus and at a dose rate of 10 microg kg(-1) min(-1)) in conscious dogs using a nociceptive withdrawal reflex (NWR) and with enantioselective measurement of plasma levels of ketamine and norketamine. Withdrawal reflexes evoked by transcutaneous single and repeated electrical stimulation (10 pulses, 5 Hz) of the digital plantar nerve were recorded from the biceps femoris muscle using surface electromyography. Ketamine did not affect NWR thresholds or the recruitment curves after a single nociceptive stimulation. Temporal summation (as evaluated by repeated stimuli) and the evoked behavioural response scores were however reduced compared to baseline demonstrating the antinociceptive activity of ketamine correlated with the peak plasma concentrations. Thereafter the plasma levels at pseudo-steady-state did not modulate temporal summation. Based on these experimental findings low-dose ketamine CRI cannot be recommended for use as a sole analgesic in the dog. PMID:18706837

  13. Phase Ⅱ study of protracted irinotecan infusion and a low-dose cisplatin for metastatic gastric cancer

    Institute of Scientific and Technical Information of China (English)

    Hiroshi Imamura; Arimichi Takabayashi; Hideaki Tsukuma; Masataka Ikeda; Hiroshi Furukawa; Toshimasa Tsujinaka; Kazumasa Fujitani; Kenji Kobayashi; Hiroyuki Narahara; Michio Kato; Haruhiko Imamoto

    2006-01-01

    AIM: To test protracted irinotecan infusion plus a lowdose cisplatin in this Phase Ⅱ trial to decrease its toxicity.METHODS: The eligibility criteria were: (1) histologically proven measurable gastric cancer; (2) performance status of 0 or 1; (3) no prior chemotherapy or completion of prior therapy at least 4 wk before enrollment; (4)adequate function of major organs; (5) no other active malignancy; and (6) written informed consent. The regimen consisted of irinotecan (60 mg/m2) on d 1 and 15 by 24-h infusion and cisplatin (10 mg/m2) on d 12 2, 3,15, 16, and 17. Treatment was repeated every 4 wk.RESULTS: Thirty-one patients were registered between April 2000 and January 2001. The response rate for all 31 patients, 20 patients without prior chemotherapy, and 11 patients with prior chemotherapy was 52% (16/31),60% (12/20), and 36% (4/11), respectively. The median survival time was 378 d. The median number of courses given to all patients was 2. Grade 4 neutropenia occurred in 11 (35%) patients, while grade 3 to 4 diarrhea or nausea occurred in 1 (3%) and 3 (10%) patients,respectively. Fatigue was minimal as grade 1 fatigue was found only in 3 (10%) patients. Other adverse events were mild and no treatment-related deaths occurred.CONCLUSION: This regimen showed a high level of activity and acceptable toxicity in patients with metastatic gastric cancer.

  14. Effects of orientation of substrate on the enhanced low-dose-rate sensitivity (ELDRS) in NPN transistors

    Institute of Scientific and Technical Information of China (English)

    LU Wu; ZHENG Yu-Zhan; WANG Yi-Yuan; REN Di-Yuan; GUO Qi; WANG Zhi-Kuan; WANG Jian-An

    2011-01-01

    The radiation effects and annealing characteristics of two types of domestic NPN bipolar junction transistors, fabricated with different orientations, were investigated under different dose-rate irradiation. The experimental results show that both types o

  15. Low-dose-rate high-let radiation cytogenetic effects on mice in vivo as model of space radiation action on mammalian

    Science.gov (United States)

    Sorokina, Svetlana; Zaichkina, Svetlana; Rozanova, Olga; Aptikaeva, Gella; Romanchenko, Sergei; Smirnova, Helene; Dyukina, Alsu; Peleshko, Vladimir

    At present time little is known concerning the biological effects of low-dose-rate high-LET radiation exposure in space. The currently available experimental data on the biological effect of low doses of chronic radiation with high-LET values, which occur under the conditions of aircraft and space flights, have been primarily obtained in the examinations of pilots and astronauts after flights. Another way of obtaining this kind of evidence is the simulation of irradiation conditions during aircraft and space flights on high-energy accelerators and the conduction of large-scale experiments on animals under these conditions on Earth. In the present work, we investigated the cytogenetic effects of low-dose-rate high-LET radiation in the dose ranges of 0.2-30 cGy (1 cGy/day) and 0.5-16 cGy (0.43 cGy/day) in the radiation field behind the concrete shield of the Serpukhov accelerator of 70 GeV protons that simulates the spectral and component composition of radiation fields formed in the conditions of high-altitude flights on SHK mice in vivo. The dose dependence, adaptive response (AR) and the growth of solid tumor were examined. For induction of AR, two groups of mice were exposed to adapting doses of 0.2-30 cGy and the doses of 0.5-16 cGy of high-LET radiation. For comparison, third group of mice from unirradiated males was chronically irradiated with X-rays at adapting doses of 10 cGy (1 cGy/day). After a day, the mice of all groups were exposed to a challenging dose of 1.5 Gy of X-rays (1 Gy/min). After 28 h, the animals of all groups were killed by the method of cervical dislocation. Bone marrow specimens for calculating micronuclei (MN) in polychromatic erythrocytes (PCE) were prepared by a conventional method with minor modifications. The influence of adapting dose of 16 cGy on the growth of solid tumor of Ehrlich ascite carcinoma was estimated by measuring the size of the tumor at different times after the inoculation of ascitic cells s.c. into the femur. It was

  16. Dosimetry TL 'in vivo' for the quality control in radiotherapy with Co-60 and brachytherapy of low dose rate

    International Nuclear Information System (INIS)

    Full text: The dosimetry 'in vivo' is used frequently as a valuable tool for the quality control in radiotherapy. Measurements of the entry and exit doses provide us of information on the precision of the technique or the procedure of used treatment; the measurement of the doses in rectal or bladder in gynecological implants contribute to perfect or to adjust the procedures in brachytherapy. Also systematic errors can be identified in particular situations that allow to optimize the treatment and to minimize errors. A study in the service of Radiotherapy of the San Roque Hospital, was realized for to control the procedures used in the treatment of different cancer therapy. Patients were selected, to which were carried out a routine planning with the system of planning of on line treatment Prowess 3000 that then were controlled with thermoluminescent dosemeters 'in vivo' using the Ceprocor Services. Skin doses were measurement in treatment of breast, pelvis, thorax, head and neck, and doses was measured in cavities of the body as oral cavity, rectal, esophagus, etc., placing the TLD inside special catheters. In the case of doses in skin, the dosimeters was placed in acrylic badges. A very good agreement was found between the measurements 'in vivo' and the plans of the planner. In some cases the control allowed to modify the doses to avoid organs damage for the radiation fields. (author)

  17. Solar Variability and the Near-Earth Environment: Mining Enhanced Low Dose Rate Sensitivity Data From the Microelectronics and Photonics Test Bed Space Experiment

    Science.gov (United States)

    Turflinger, T.; Schmeichel, W.; Krieg, J.; Titus, J.; Campbell, A.; Reeves, M.; Marshall (P.); Hardage, Donna (Technical Monitor)

    2004-01-01

    This effort is a detailed analysis of existing microelectronics and photonics test bed satellite data from one experiment, the bipolar test board, looking to improve our understanding of the enhanced low dose rate sensitivity (ELDRS) phenomenon. Over the past several years, extensive total dose irradiations of bipolar devices have demonstrated that many of these devices exhibited ELDRS. In sensitive bipolar transistors, ELDRS produced enhanced degradation of base current, resulting in enhanced gain degradation at dose rates 1 rd(Si)/s. This Technical Publication provides updated information about the test devices, the in-flight experiment, and both flight-and ground-based observations. Flight data are presented for the past 5 yr of the mission. These data are compared to ground-based data taken on devices from the same date code lots. Information about temperature fluctuations, power shutdowns, and other variables encountered during the space flight are documented.

  18. Correlation between the rate of bioreduction of nitroxide spin label by human tumor cells and their low-dose radiation response

    International Nuclear Information System (INIS)

    The authors discuss a correlation observed between the bioreduction of nitroxide spin label by four human tumor cell lines and a normal tissue fibroblast clone and their low-dose radiation response, specifically their DQ. In measurements of the bioreduction rate of several other cell lines, this correlation appears to persist. In order to define the mechanism of this correlation, they have begun by subtly altering the measurement conditions. The original conditions for measurement involved adding the spin label to cells whose culture medium had been changed (the label was added to the new medium). By delaying the addition of the label to the culture medium, they substantially reduced the variation of the bioreduction rate between the cell lines. This implies that the fresh medium provides a nonspecific irritant or disequilibrium to the cultured cell system to which they response variably by accelerating, among other things, the metabolic process responsible for spin label bioreduction

  19. Nutrient intake and nutrient patterns and risk of lung cancer among heavy smokers: results from the COSMOS screening study with annual low-dose CT

    International Nuclear Information System (INIS)

    The role of nutrients in lung cancer aetiology remains controversial and has never been evaluated in the context of screening. Our aim was to investigate the role of single nutrients and nutrient patterns in the aetiology of lung cancer in heavy smokers. Asymptomatic heavy smokers (≥20 pack-years) were invited to undergo annual low-dose computed tomography. We assessed diet using a self-administered food frequency questionnaire and collected information on multivitamin supplement use. We performed principal component analysis identifying four nutrient patterns and used Cox proportional Hazards regression to assess the association between nutrients and nutrients patterns and lung cancer risk. During a mean follow-up of 5.7 years, 178 of 4,336 participants were diagnosed with lung cancer by screening. We found a significant risk reduction of lung cancer with increasing vegetable fat consumption (HR for highest vs. lowest quartile = 0.50, 95 % CI = 0.31–0.80; P-trend = 0.02). Participants classified in the high “vitamins and fiber” pattern score had a significant risk reduction of lung cancer (HR = 0.57; 95 % CI = 0.36–0.90, P-trend = 0.01). Among heavy smokers enrolled in a screening trial, high vegetable fat intake and adherence to the “vitamin and fiber” nutrient pattern were associated with reduced lung cancer incidence.

  20. Nutrient intake and nutrient patterns and risk of lung cancer among heavy smokers: results from the COSMOS screening study with annual low-dose CT.

    Science.gov (United States)

    Gnagnarella, Patrizia; Maisonneuve, Patrick; Bellomi, Massimo; Rampinelli, Cristiano; Bertolotti, Raffaella; Spaggiari, Lorenzo; Palli, Domenico; Veronesi, Giulia

    2013-06-01

    The role of nutrients in lung cancer aetiology remains controversial and has never been evaluated in the context of screening. Our aim was to investigate the role of single nutrients and nutrient patterns in the aetiology of lung cancer in heavy smokers. Asymptomatic heavy smokers (≥20 pack-years) were invited to undergo annual low-dose computed tomography. We assessed diet using a self-administered food frequency questionnaire and collected information on multivitamin supplement use. We performed principal component analysis identifying four nutrient patterns and used Cox proportional Hazards regression to assess the association between nutrients and nutrients patterns and lung cancer risk. During a mean follow-up of 5.7 years, 178 of 4,336 participants were diagnosed with lung cancer by screening. We found a significant risk reduction of lung cancer with increasing vegetable fat consumption (HR for highest vs. lowest quartile = 0.50, 95% CI = 0.31-0.80; P-trend = 0.02). Participants classified in the high "vitamins and fiber" pattern score had a significant risk reduction of lung cancer (HR = 0.57; 95% CI = 0.36-0.90, P-trend = 0.01). Among heavy smokers enrolled in a screening trial, high vegetable fat intake and adherence to the "vitamin and fiber" nutrient pattern were associated with reduced lung cancer incidence.

  1. 低剂量螺旋CT扫描在周围型肺癌诊断中的临床应用价值%Low Dose Spiral CT Scanning in the Diagnosis of Peripheral Lung Cancer Clinical Application Value

    Institute of Scientific and Technical Information of China (English)

    何揆

    2014-01-01

    , Ye Zheng sign, blood vessels, cluster sign, pleural sag and obstructive pneumonia or atelectasis rate of peripheral lung cancer signs show no significant decrease, the dif erence is not statistical y significant ( > 0. 05). Conclusion Low-dose spiral CT scanning in reducing radiation dose of at the same time, also can clearly show various signs of peripheral lung cancer, in the diagnosis of peripheral lung cancer has high clinical value.

  2. Neutron dosimetry for low dose rate Cf-252 AT sources and adherence to recent clinical dosimetry protocol for brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Rivard, M.J.; Wierzbicki, J.G.; Van den Heuvel, F. [Wayne State Univ., Detroit, MI (United States). Dept. of Radiation Oncology; Martin, R.C. [Oak Ridge National Lab., TN (United States). Chemical Technology Div.

    1997-12-01

    In 1995, the American Association of Physicists in Medicine Task Group 43 (AAPM TG-43) published a protocol obsoleting all mixed-field radiation dosimetry for Cf-252. Recommendations for a new brachytherapy dosimetry formalism made by this Task Group favor quantification of source strength in terms of air kerma rather than apparent Curies or other radiation units. Additionally, representation of this dosimetry data in terms of radial dose functions, anisotropy functions, geometric factors, and dose rate constants are in an angular and radial (spherical) coordinate system as recommended, rather than the along-away dosimetry data (Cartesian coordinate system) currently available. This paper presents the initial results of calculated neutron dosimetry in a water phantom for a Cf-252 applicator tube (AT) type medical source soon available from Oak Ridge National Laboratory (ORNL).

  3. Randomized Double-Blind 2 × 2 Trial of Low-Dose Tamoxifen and Fenretinide for Breast Cancer Prevention in High-Risk Premenopausal Women

    Science.gov (United States)

    Decensi, Andrea; Robertson, Chris; Guerrieri-Gonzaga, Aliana; Serrano, Davide; Cazzaniga, Massimiliano; Mora, Serena; Gulisano, Marcella; Johansson, Harriet; Galimberti, Viviana; Cassano, Enrico; Moroni, Simona M.; Formelli, Franca; Lien, Ernst A.; Pelosi, Giuseppe; Johnson, Karen A.; Bonanni, Bernardo

    2009-01-01

    Purpose Tamoxifen and fenretinide are active in reducing premenopausal breast cancer risk and work synergistically in preclinical models. The authors assessed their combination in a two-by-two biomarker trial. Patients and Methods A total of 235 premenopausal women with pT1mic/pT1a breast cancer (n = 21), or intraepithelial neoplasia (IEN, n = 160), or 5-year Gail risk ≥ 1.3% (n = 54) were randomly allocated to either tamoxifen 5 mg/d, fenretinide 200 mg/d, their combination, or placebo. We report data for plasma insulin-like growth factor I (IGF-I), mammographic density, uterine effects, and breast neoplastic events after 5.5 years. Results During the 2-year intervention, tamoxifen significantly lowered IGF-I and mammographic density by 12% and 20%, respectively, fenretinide by 4% and 10% (not significantly), their combination by 20% and 22%, with no evidence for a synergistic interaction. Tamoxifen increased endometrial thickness principally in women becoming postmenopausal, whereas fenretinide decreased endometrial thickness significantly. The annual rate of breast neoplasms (n = 48) was 3.5% ± 1.0%, 2.1% ± 0.8%, 4.7% ± 1.3%, and 5.2% ± 1.3% in the tamoxifen, fenretinide, combination, and placebo arms, respectively, with hazard ratios (HRs) of 0.70 (95% CI, 0.32 to 1.52), 0.38 (95% CI, 0.15 to 0.90), and 0.96 (95% CI, 0.46 to 1.99) relative to placebo (tamoxifen × fenretinide adverse interaction P = .03). There was no clear association with tumor receptor type. Baseline IGF-I and mammographic density did not predict breast neoplastic events, nor did change in mammographic density. Conclusion Despite favorable effects on plasma IGF-I levels and mammographic density, the combination of low-dose tamoxifen plus fenretinide did not reduce breast neoplastic events compared to placebo, whereas both single agents, particularly fenretinide, showed numerical reduction in annual odds of breast neoplasms. Further follow-up is indicated. PMID:19597031

  4. Comparative response of dogs and monkeys to sublethal acute and continuous low dose-rate gamma-ray exposure

    International Nuclear Information System (INIS)

    Monkeys (Macaca mulatta) and dogs (beagle) were given thirteen 100-rad gamma-ray doses at 28-day intervals. The comparative response (injury and recovery) of the hematopoietic system of the two species was observed at 7-day intervals during the exposure regime. At 84 days after the thirteenth gamma-ray dose, the 1300-rad conditioned and control dogs and monkeys were challenged continuously with 35 R/day until death to determine the amount of radiation-induced injury remaining in conditioned animals as a reduction in mean survival time. Dogs (50 percent) and monkeys (8 percent) died from injury incurred during the conditioning exposures. Thus, the comparative response of dogs and monkeys to dose protraction by acute dose fractionation was similar to what might be expected from a single acute dose. Mean survival times for nonconditioned dogs and monkeys during continuous exposure at 35 R/day were the same (approximately 1400 h). Thus, hematopoietic response of the two species by this method of dose protraction was not significantly different. Mean survival times of conditioned dogs and monkeys during the continuous 35 R/day gamma-ray challenge exposure were greater than for their control counterparts. Thus, the long-term radiation-induced injury was not measurable by this method. Conditioning doses of more than four times the acute LD50-30 in dogs and approximately two times that of monkeys served only to increase both mean survival time and variance in a gamma-ray stress environment with a dose rate of 35 R/day

  5. Gamma irradiation facility optimization for very low dose rates; Otimizacao de uma instalacao de irradiacao gama para taxas de dose muito baixas

    Energy Technology Data Exchange (ETDEWEB)

    Rzyski, Barbara M.; Galante, Ana M.S.; Silva, Rosemeire E. da; Somessari, Elizabeth; Silveira, Carlos G. da; Carvalho, Ricardo N.; Vieira, Jose M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1997-10-01

    Many researches, mainly those linked to medicine and biology, sometimes require low dose irradiations. Sources with activity above 3.7 x 10{sup 13} Bq, even if the collimate beam good geometry is maintained, do not tolerate irradiations without device modifications. A Co-60 panoramic source, with 8.51 x 10{sup 13} Bq, was adapted to allow irradiation range of 0.2-100 Gy with dose rates within the 0.5-1 Gy/min range. In this specific case, some important aspects that allow to offer to the user an adequate dosimetric standard are shown. Some of these aspects consider the accumulated dose during the positioning of the source, the sample rotation and the errors in the lower limits of the required dose range. (author). 2 refs., 3 figs.

  6. Effect of irradiation temperature and strain rate on the mechanical properties of V-4Cr-4Ti irradiated to low doses in fission reactors

    Energy Technology Data Exchange (ETDEWEB)

    Zinkle, S.J.; Snead, L.L.; Rowcliffe, A.F.; Alexander, D.J.; Gibson, L.T. [Oak Ridge National Lab., TN (United States)

    1998-09-01

    Tensile tests performed on irradiated V-(3-6%)Cr-(3-6%)Ti alloys indicate that pronounced hardening and loss of strain hardening capacity occurs for doses of 0.1--20 dpa at irradiation temperatures below {approximately}330 C. The amount of radiation hardening decreases rapidly for irradiation temperatures above 400 C, with a concomitant increase in strain hardening capacity. Low-dose (0.1--0.5 dpa) irradiation shifts the dynamic strain aging regime to higher temperatures and lower strain rates compared to unirradiated specimens. Very low fracture toughness values were observed in miniature disk compact specimens irradiated at 200--320 C to {approximately}1.5--15 dpa and tested at 200 C.

  7. Adaptive response and genetic instability induced by a low-dose rate radiation simulating the high-altitude flight conditions on mice in vivo

    International Nuclear Information System (INIS)

    Complete text of publication follows. In the present work, we investigated the effect of a low-dose rate of high-LET radiation that simulates the spectral and component composition of radiation fields formed in the conditions of high-altitude flights on mice in vivo. The dose dependence, adaptive response, and genetic instability in generation F1 born from males irradiated under these conditions were examined in polychromatic erythrocytes of bone marrow using the micronucleus test. Two-month-old males of SHK white mongrel mice were used. Irradiation was performed for 24 h a day in the radiation field behind the concrete shield of the U-70 accelerator of 70 GeV protons (Serpukhov), which adequately simulates radiation field formed in the atmosphere at a height of about 10 km, to accumulate doses of 11.5, 21.5 and 31.5 cGy (1 cGy/day). The experiments demonstrated that: 1) irradiation of mice in vivo with these doses of low dose rate high-LET radiation leads to an increase in cytogenetic damage in polychromatic erythrocytes; 2) irradiation of mice with these doses induces no adaptive response in polychromatic erythrocytes as opposite to γ-radiation; and 3) in mice of the F1 generation born from males irradiated with doses of 11.5, 21.5 and 31.5 cGy, an increase in sensitivity to additional irradiation with a dose of 1.5 Gy of γ-radiation and the absence of adaptive response compared with the descendants of unirradiated males occur. These data indicate a genetic instability in generation F1 born from irradiated males.

  8. Combined use of positron emission tomography and volume doubling time in lung cancer screening with low-dose CT scanning

    DEFF Research Database (Denmark)

    Ashraf, H; Dirksen, A; Jakobsen, Annika Loft;

    2011-01-01

    In lung cancer screening the ability to distinguish malignant from benign nodules is a key issue. This study evaluates the ability of positron emission tomography (PET) and volume doubling time (VDT) to discriminate between benign and malignant nodules....

  9. Influence of dose rate on leukemogenesis in mice irradiated by gamma rays at a high dose rate or low dose rates

    International Nuclear Information System (INIS)

    The purpose of this study was to assess the extent of the effect of dose rate on tumorigenesis, focusing on myeloid leukemia, one of the typical neoplasias induced by radiation. In the experiment, C3H/He male mice were irradiated with gamma-rays at various doses at a dose rate of 0.88Gy/min, or 0.30mGy/min or 0.016mGy/min, and equations of dose response curves for leukemia were derived from data on the incidence in each group by the least square method. Each equation fitted well with the linear quadratic equation by coefficiency of more than 90%. The extent of the dose rate effect was expressed as dose and dose rate effectiveness factor (DDREF) based on the definition by ICRP-Publication 60. We obtained DDREF by dividing the slope factor of the tangential line of group H (0.88Gy/min) by that of group L-1 (0.30mGy/min) or L-2 (0.016mGy/min), the tangential lines being drawn from the value of the incidence of the control group on the dose response curve. The value of group H to group L-1 was 12.00/1.71=7.022, and that of group H to group L-2 was 12.00/2.56=4.69. These values indicated that reduction of the dose rate caused a decrease in the induction of leukemia, ranging between the values 2 and 10 in the NCRP 1990 report. (author)

  10. IKKβ/NF-κB mediated the low doses of bisphenol A induced migration of cervical cancer cells.

    Science.gov (United States)

    Ma, Xue-Feng; Zhang, Jie; Shuai, Han-Lin; Guan, Bao-Zhang; Luo, Xin; Yan, Rui-Ling

    2015-05-01

    Cervical cancer is considered as the second most common female malignant disease. There is an urgent need to illustrate risk factors which can trigger the motility of cervical cancer cells. Our present study revealed that nanomolar concentration of bisphenol A (BPA) significantly promoted the in vitro migration and invasion of cervical cancer HeLa, SiHa, and C-33A cells. Further, BPA treatment increased the expression of metalloproteinase-9 (MMP-9) and fibronectin (FN) in both HeLa and SiHa cells, while did not obviously change the expression of MMP-2, vimentin (Vim) or N-Cadherin (N-Cad). BAY 11-7082, the inhibitor of NF-κB, significantly abolished BPA induced up regulation of FN and MMP-9 in cervical cancer cells. While the inhibitors of PKA (H89), ERK1/2 (PD 98059), EGFR (AG1478), or PI3K/Akt (LY294002) had no effect on the expression of either FN or MMP-9. BPA treatment rapidly increased the phosphorylation of both IκBα and p65, stimulated nuclear translocation, and up regulated the promoter activities of NF-κB. The BPA induced up regulation of MMP-9 and FN and activation of NF-κB were mediated by phosphorylation of IKKβ via PKC signals. Collectively, our study found for the first time that BPA stimulated the cervical cancer migration via IKK-β/NF-κB signals.

  11. Reanalysis of cancer mortality in Japanese A-bomb survivors exposed to low doses of radiation: bootstrap and simulation methods

    Directory of Open Access Journals (Sweden)

    Dropkin Greg

    2009-12-01

    Full Text Available Abstract Background The International Commission on Radiological Protection (ICRP recommended annual occupational dose limit is 20 mSv. Cancer mortality in Japanese A-bomb survivors exposed to less than 20 mSv external radiation in 1945 was analysed previously, using a latency model with non-linear dose response. Questions were raised regarding statistical inference with this model. Methods Cancers with over 100 deaths in the 0 - 20 mSv subcohort of the 1950-1990 Life Span Study are analysed with Poisson regression models incorporating latency, allowing linear and non-linear dose response. Bootstrap percentile and Bias-corrected accelerated (BCa methods and simulation of the Likelihood Ratio Test lead to Confidence Intervals for Excess Relative Risk (ERR and tests against the linear model. Results The linear model shows significant large, positive values of ERR for liver and urinary cancers at latencies from 37 - 43 years. Dose response below 20 mSv is strongly non-linear at the optimal latencies for the stomach (11.89 years, liver (36.9, lung (13.6, leukaemia (23.66, and pancreas (11.86 and across broad latency ranges. Confidence Intervals for ERR are comparable using Bootstrap and Likelihood Ratio Test methods and BCa 95% Confidence Intervals are strictly positive across latency ranges for all 5 cancers. Similar risk estimates for 10 mSv (lagged dose are obtained from the 0 - 20 mSv and 5 - 500 mSv data for the stomach, liver, lung and leukaemia. Dose response for the latter 3 cancers is significantly non-linear in the 5 - 500 mSv range. Conclusion Liver and urinary cancer mortality risk is significantly raised using a latency model with linear dose response. A non-linear model is strongly superior for the stomach, liver, lung, pancreas and leukaemia. Bootstrap and Likelihood-based confidence intervals are broadly comparable and ERR is strictly positive by bootstrap methods for all 5 cancers. Except for the pancreas, similar estimates of

  12. Targeting heat shock protein 70 using gold nanorods enhances cancer cell apoptosis in low dose plasmonic photothermal therapy.

    Science.gov (United States)

    Ali, Moustafa R K; Ali, Hala R; Rankin, Carl R; El-Sayed, Mostafa A

    2016-09-01

    Plasmonic photothermal therapy (PPTT) is a promising cancer treatment where plasmonic nanoparticles are used to convert near infrared light to localized heat to cause cell death, mainly via apoptosis and necrosis. Modulating PPTT to induce cell apoptosis is more favorable than necrosis. Herein, we used a mild treatment condition using gold nanorods (AuNRs) to trigger apoptosis and tested how different cell lines responded to it. Three different cancer cell lines of epithelial origin: HSC (oral), MCF-7 (breast) and Huh7.5 (liver) had comparable AuNRs uptake and were heated to same environmental temperature (under 50 °C). However, Huh7.5 cells displayed a significant increase in cell apoptosis after PPTT as compared to the other two cell lines. As HSP70 is known to increase cellular resistance to heat, we determined relative HSP70 levels in these cells and results indicated that Huh7.5 cells had ten-fold decreased levels of HSP70 as compared with HSC and MCF-7 cells. We then down-regulated HSP70 with a siRNA and observed that all three cell lines displayed significant reduction in viability and an increase in apoptosis after PPTT. As an enhancement to PPTT, we conjugated AuNRs with Quercetin, an inhibitor of HSP70 which displayed anti-cancer effects via apoptosis. PMID:27318931

  13. Late Urinary Side Effects 10 Years After Low-Dose-Rate Prostate Brachytherapy: Population-Based Results From a Multiphysician Practice Treating With a Standardized Protocol and Uniform Dosimetric Goals

    Energy Technology Data Exchange (ETDEWEB)

    Keyes, Mira, E-mail: mkeyes@bccancer.bc.ca; Miller, Stacy; Pickles, Tom; Halperin, Ross; Kwan, Winkle; Lapointe, Vincent; McKenzie, Michael; Spadinger, Ingrid; Pai, Howard; Chan, Elisa K.; Morris, W. James

    2014-11-01

    Purpose: To determine late urinary toxicity (>12 months) in a large cohort of uniformly treated low-dose-rate prostate brachytherapy patients. Methods and Materials: From 1998 to 2009, 2709 patients with National Comprehensive Cancer Network–defined low-risk and low-tier intermediate-risk prostate cancer were treated with Iodine 125 ({sup 125}I) low-dose-rate prostate brachytherapy; 2011 patients with a minimum of 25 months of follow-up were included in the study. Baseline patients, treatment, implant factors, and late urinary toxicity (Radiation Therapy Oncology Group [RTOG] grading system and International Prostate Symptom Score [IPSS]) were recorded prospectively. Time to IPSS resolution, late RTOG genitourinary toxicity was examined with Kaplan-Meier and log-rank tests. Cox proportional hazards regression was done for individual covariates and multivariable models. Results: Median follow-up was 54.5 months (range, 2-13 years). Actuarial toxicity rates reached 27% and 10% (RTOG ≥2 and ≥3, respectively) at 9-13 years. Symptoms resolved quickly in the majority of patients (88% in 6-12 months). The prevalence of RTOG 0, 1, 2, 3, and 4 toxicity with a minimum of 7 years' follow-up was 70%, 21%, 6.4%, 2.3%, and 0.08%, respectively. Patients with a larger prostate volume, higher baseline IPSS, higher D90, acute toxicity, and age >70 years had more late RTOG ≥2 toxicity (all P≤.02). The IPSS resolved slower in patients with lower baseline IPSS and larger ultrasound prostate volume, those not receiving androgen deprivation therapy, and those with higher D90. The crude rate of RTOG 3 toxicity was 6%. Overall the rate of transurethral resection of the prostate was 1.9%; strictures, 2%; incontinence, 1.3%; severe symptoms, 1.8%; late catheterization, 1.3%; and hematuria, 0.8%. The majority (80%) resolved their symptoms in 6-12 months. Conclusion: Long-term urinary toxicity after brachytherapy is low. Although actuarial rates increase with longer

  14. Semicontinuous Low-Dose-Rate Teletherapy for the Treatment of Recurrent Glial Brain Tumors: Final Report of a Phase I/II Study

    International Nuclear Information System (INIS)

    Purpose: Semicontinuous low-dose-rate teletherapy (SLDR) is a novel irradiation strategy that exploits the increased radiosensitivity of glial cells in a narrow range of reduced dose rate. We present the final report of a prospective Phase I/II study testing the feasibility of SLDR for the treatment of recurrent gliomas. Methods and Materials: Patients with previously irradiated recurrent gliomas were enrolled from November 1993 to March 1998. Patients received SLDR, delivered 6 to 8 hours/day at a dose rate of 40 to 50 cGy/hour for a total dose of 30 to 35 Gy given over 12 days using a modified cobalt-60 treatment unit. Acute central nervous system toxicity after SLDR treatment was the primary endpoint. Overall survival was a secondary endpoint. Results: Twenty patients were enrolled (14 World Health Organization Grade 4 glioma, 5 Grade 2 glioma, 1 ependymoma). No patients developed ≥Grade 3 central nervous system toxicity at 3 months without radiographic evidence of tumor progression. Overall survival after SLDR was 56% at 6 months, 28% at 12 months, and 17% at 24 months. One patient survived >48 months, and 1 patient survived >60 months after SLDR treatment. Re-resection before SLDR treatment significantly improved 1-year overall survival for all patients and patients with Grade 4 glioma. Conclusion: The delivery of SLDR is feasible in patients with recurrent gliomas and resulted in improved outcomes for patients who underwent re-resection. There were 2 long-term survivors (>48 months). This pilot study supports the notion that reduced dose rate influences the efficacy and tolerance of reirradiation in the treatment of recurrent gliomas.

  15. M-BAND Analysis of Chromosome Aberration In Human Epithelial Cells exposed to Gamma-ray and Secondary Neutrons of Low Dose Rate

    Science.gov (United States)

    Hada, M.; Saganti, P. B.; Gersey, B.; Wilkins, R.; Cucinotta, F. A.; Wu, H.

    2007-01-01

    High-energy secondary neutrons, produced by the interaction of galactic cosmic rays with the atmosphere, spacecraft structure and planetary surfaces, contribute to a significant fraction to the dose equivalent in crew members and passengers during commercial aviation travel, and astronauts in space missions. The Los Alamos Nuclear Science Center (LANSCE) neutron facility's "30L" beam line is known to generate neutrons that simulate the secondary neutron spectrum of the Earth's atmosphere at high altitude. The neutron spectrum is also similar to that measured onboard spacecraft like the MIR and the International Space Station (ISS). To evaluate the biological damage, we exposed human epithelial cells in vitro to the LANSCE neutron beams at an entrance dose rate of 2.5 cGy/hr or gamma-ray at 1.7cGy/hr, and assessed the induction of chromosome aberrations that were identified with mBAND. With this technique, individually painted chromosomal bands on one chromosome allowed the identification of inter-chromosomal aberrations (translocation to unpainted chromosomes) and intra-chromosomal aberrations (inversions and deletions within a single painted chromosome). Compared to our previous results for gamma-rays and 600 MeV/nucleon Fe ions of high dose rate, the neutron data showed a higher frequency of chromosome aberrations. However, detailed analysis of the inversion type revealed that all of the three radiation types in the study induced a low incidence of simple inversions. The low dose rate gamma-rays induced a lower frequency of chromosome aberrations than high dose rate gamma-rays, but the inversion spectrum was similar for the same cytotoxic effect. The distribution of damage sites on chromosome 3 for different radiation types will also be discussed.

  16. Behavior and awareness of thyroid cancer patients in Korea having non-hospitalized low-dose radioiodine treatment with regard to radiation safety

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seog Gyun; Paeng, Jin Chul; Eo, Jae Seon; Shim, Hye Kyung; Kang, Keon Wook; Chung, June Key; Lee, Myung Chul; Lee, Dong Soo [College of Medicine, Seoul National University, Seoul (Korea, Republic of)

    2010-12-15

    With the recent increase in incidence of thyroid cancer, non-hospitalized low-dose (NH-LD) radioiodine treatment (RIT) has also increased rapidly. The radioactivity limit that is allowed to be administered without hospitalization depends on individual calculation, based partly on patients' behavior. In this study, Korean patients' behavior in relation to radiation safety in NHLD RIT was surveyed. A total of 218 patients who underwent NH-LD RIT of 1.1 GBq {sup 131}I in a single center were surveyed. The patients underwent RIT with a standard protocol and the survey was performed by interview when they visited subsequently for a whole-body scan. The survey questionnaire included three parts of questions: general information, behavior relating to isolation during RIT, and awareness of radiation safety. After administration of radioiodine, 40% of patients who returned home used mass transportation, and another 47% went home by taxi or in car driven by another person. Isolation at home was generally sufficient. However, 7% of patients did not stay in a separate room. Among the 218 patients, 34% did not go home and chose self-isolation away from home, mostly due to concerns about radiation safety of family members. However, the places were mostly public places, including hotels, resorts, and hospitals. About half of the patients replied that access to radiation safety information was not easy and their awareness of radiation safety was not satisfactory. As a result, 45% of patients wanted hospitalized RIT. In many countries, including Korea, RIT is continuously increasing. Considering the radiation safety of patients' family members or the public and the convenience of patients, the pretreatment education of patients should be enhanced. In addition, the hospitalization of patients having low-dose therapy is recommended to be seriously considered and expanded, with the expansion of dedicated treatment facilities

  17. An association between low-dose hyper-radiosensitivity and the early G2-phase checkpoint in normal fibroblasts of cancer patients.

    Science.gov (United States)

    Słonina, Dorota; Gasińska, Anna; Biesaga, Beata; Janecka, Anna; Kabat, Damian

    2016-03-01

    In our previous study, low-dose hyper-radiosensitivity (HRS) effect was demonstrated for normal fibroblasts (asynchronous and G2-phase enriched) of 4 of the 25 cancer patients investigated. For the rest of patients, HRS was not defined in either of the 2 fibroblast populations. Thus, the study indicated that G2-phase enrichment had no influence on HRS identification. The conclusion contradicts that reported for human tumor cells, and suggests different mechanism of HRS in normal human cells. In the present paper we report, for the first time, the activity of early G2-phase checkpoint after low-dose irradiation in normal fibroblasts of these 4 HRS-positive patients and 4 HRS-negative patients and answer the question regarding the role of this checkpoint in normal human cells. The response of the early G2-phase checkpoint was determined by assessment of the progression of irradiated cells into mitosis using the mitotic marker, phosphorylated histone H3. We found evident differences in the activity of the early G2-phase checkpoint between HRS-positive and HRS-negative fibroblasts. In HRS-positive fibroblasts the checkpoint was not triggered and DNA damage was not recognized after doses lower than 0.2Gy resulting in HRS response. On the contrary, in HRS-negative fibroblasts the early G2-phase checkpoint was activated regardless of the dose in the range 0.1-2Gy. In conclusion, although cell cycle phase has no effect on the presence of HRS effect in normal human fibroblasts, the data reported here indicate that HRS response in these cells is associated with the functioning of early G2-phase checkpoint in a threshold-dose dependent manner, similarly as it takes place in most of human tumor and other cells. PMID:26725161

  18. Behavior and awareness of thyroid cancer patients in Korea having non-hospitalized low-dose radioiodine treatment with regard to radiation safety

    International Nuclear Information System (INIS)

    With the recent increase in incidence of thyroid cancer, non-hospitalized low-dose (NH-LD) radioiodine treatment (RIT) has also increased rapidly. The radioactivity limit that is allowed to be administered without hospitalization depends on individual calculation, based partly on patients' behavior. In this study, Korean patients' behavior in relation to radiation safety in NHLD RIT was surveyed. A total of 218 patients who underwent NH-LD RIT of 1.1 GBq 131I in a single center were surveyed. The patients underwent RIT with a standard protocol and the survey was performed by interview when they visited subsequently for a whole-body scan. The survey questionnaire included three parts of questions: general information, behavior relating to isolation during RIT, and awareness of radiation safety. After administration of radioiodine, 40% of patients who returned home used mass transportation, and another 47% went home by taxi or in car driven by another person. Isolation at home was generally sufficient. However, 7% of patients did not stay in a separate room. Among the 218 patients, 34% did not go home and chose self-isolation away from home, mostly due to concerns about radiation safety of family members. However, the places were mostly public places, including hotels, resorts, and hospitals. About half of the patients replied that access to radiation safety information was not easy and their awareness of radiation safety was not satisfactory. As a result, 45% of patients wanted hospitalized RIT. In many countries, including Korea, RIT is continuously increasing. Considering the radiation safety of patients' family members or the public and the convenience of patients, the pretreatment education of patients should be enhanced. In addition, the hospitalization of patients having low-dose therapy is recommended to be seriously considered and expanded, with the expansion of dedicated treatment facilities

  19. How to understand low dose risks

    International Nuclear Information System (INIS)

    It is well established that those who were exposed to ionizing radiation have increased risks of developing malignancies. The magnitude of the risk varies depending on not only the dose but also age at the time of exposure, gender, background incidence rate etc. In the case of atomic bomb survivors, the relative risk of cancer is linearly related to the dose, and the sex averaged relative risk (exposure age is 30, risk calculation is when they reached age 70) is 1.5 at 1 Gy. Because the increased risks below 100 to 200 mGy are too small and not statistically significant, there are arguments in interpreting the risks at the low dose range. (author)

  20. [Low dose ionising radiation and cancer: findings and methods. Report of a meeting and consequences for Switzerland].

    Science.gov (United States)

    Schüler, G; Gutzwiller, F

    1991-01-01

    Today's society is concerned about the dangers of ionising radiation, especially in the aftermath of Chernobyl. On the other hand, there exists a widespread lack of understanding radiation biology and radioepidemiology--the very sciences which provide the data from which today's risk estimates have been derived. The papers in this issue of the Journal were presented at a workshop on "Low level radiation and cancer: data and methods" held on 10th-11th December in Feuisberg, near Zurich. The meeting was organised by the Institute of Social and Preventive Medicine of the University of Zurich under the auspices of the Swiss Federal Office of Public Health. Its aims were threefold. First, to give an introduction to some basic facts and methodological issues in radiation physics, biology and epidemiology. Secondly, to give an overview of the availability of data for radioepidemiological research in Switzerland and, thirdly, to evaluate possible research strategies in this country. A list of some notions and units commonly used in the radiation sciences serves an an introduction to the field (G. Schüler et al.). In using units and notions it is important to distinguish the description of biological experiments and epidemiological observations from definitions and risk projections proposed by international reports and consensus bodies for radioprotection purposes. The next papers deal more specifically with selected aspects of the basic sciences. Dosimetry means quantifying the physical effects of ionizing radiation in human tissue; this is not a straight-forward procedure (I. Cordt). The foundations of general radiation biology are succinctly summarised by C. Michel. An account of our present knowledge and theories of radiation carcinogenesis is provided by W. Burkart. W Lutz compares dose-response models of chemical carcinogenesis with those used in radiation carcinogenesis. During the last decade the epidemiological foundations of radioprotection have changed

  1. Low-dose Photofrin-induced PDT offers excellent clinical response with minimal morbidity in chest wall recurrence of breast cancer

    Science.gov (United States)

    Allison, Ron; Mang, Thomas S.

    2000-03-01

    Limited therapeutic options exist when chest wall recurrence form breast cancer progresses despite standard salvage treatment. As photodynamic therapy offers excellent response for cutaneous lesions this may be a possible indication for PDT. A total of 102 treatment fields were illuminated on 9 women with biopsy proven chest wall recurrence of breast cancer which was progressing despite salvage surgery, radiation, and chemi-hormonal therapy. PDT consisted of outpatient IV infusion of Photofrin at 0.8 mg/kg followed 48 hours laser by illumination at 140-170 J/cm2 via a KTP Yag laser coupled to a dye unit. No patient was lost to follow up. At 6 months post PDT; complete response, defined as total lesion elimination was 89 percent, partial response 8 percent, and no response 3 percent. No photosensitivity was seen and no patient developed scarring, fibrosis, or healing difficulties. Low dose Photofrin induced PDT is very active against chest wall lesions. Despite fragile and heavily pre-treated tissues, excellent clinical and cosmetic outcome was obtained. PDT is an underutilized modality for this indication.

  2. mBAND analysis of chromosome aberrations in human epithelial cells induced by gamma-rays and secondary neutrons of low dose rate.

    Science.gov (United States)

    Hada, M; Gersey, B; Saganti, P B; Wilkins, R; Cucinotta, F A; Wu, H

    2010-08-14

    Human risks from chronic exposures to both low- and high-LET radiation are of intensive research interest in recent years. In the present study, human epithelial cells were exposed in vitro to gamma-rays at a dose rate of 17 mGy/h or secondary neutrons of 25 mGy/h. The secondary neutrons have a broad energy spectrum that simulates the Earth's atmosphere at high altitude, as well as the environment inside spacecrafts like the Russian MIR station and the International Space Station (ISS). Chromosome aberrations in the exposed cells were analyzed using the multicolor banding in situ hybridization (mBAND) technique with chromosome 3 painted in 23 colored bands that allows identification of both inter- and intrachromosome exchanges including inversions. Comparison of present dose responses between gamma-rays and neutron irradiations for the fraction of cells with damaged chromosome 3 yielded a relative biological effectiveness (RBE) value of 26+/-4 for the secondary neutrons. Our results also revealed that secondary neutrons of low dose rate induced a higher fraction of intrachromosome exchanges than gamma-rays, but the fractions of inversions observed between these two radiation types were indistinguishable. Similar to the previous findings after acute radiation exposures, most of the inversions observed in the present study were accompanied by other aberrations. The fractions of complex type aberrations and of unrejoined chromosomal breakages were also found to be higher in the neutron-exposed cells than after gamma-rays. We further analyzed the location of the breaks involved in chromosome aberrations along chromosome 3, and observed hot spots after gamma-ray, but not neutron, exposures. PMID:20338263

  3. Radiation cancer analysis and low dose risk estimation: new developments and perspectives - conference to be held Feb 2002. Final technical report for period November 1, 2001--October 31, 2002

    International Nuclear Information System (INIS)

    The Proceedings of the 20th LH Gray Conference on Radiation Cancer Analysis and Low Dose Risk Estimation: New Developments and Perspectives (17-21 February 2002, Ede, the Netherlands) comprises 32 peer-reviewed papers on invited and proffered contributions to the conference with a preface by the guest editors. The on-going discussion of low dose radiation risk; the issue of the linear, non-threshold extrapolation; and the anticipated new recommendations, e.g. from BEIR and ICRP, provided the back-drop for the conference. The meeting dealt with topics such as basic mechanisms and bystander effects, cancer modeling, cancer genetics, radon exposure and lung cancer risk, cancer after medical exposure, cancer risk estimation, dose-effect relationships, and application to radiation protection

  4. Age and sex dependence in tumorigenesis in mice by continuous low-dose-rate gamma-ray whole-body irradiation

    International Nuclear Information System (INIS)

    We investigated the dependency of sex and age in mice in the induction of neoplasms by gamma-rays from cesium-137 at a low dose rate of 0.375Gy/22h/day. Thymic lymphomas occurred significantly at the same incidence in both sexes, and more frequently when younger mice were exposed to radiation. Strain C57BL/6J mice were divided into 8 groups, which were whole-body irradiated with a total dose of 39Gy for 105 days each. The exposure was begun at 28 days of age (male:AM1, female:AF1), and then stepwise increasing the starting age by 105 days, i.e., from 133 days (AM2 and AF2), from 238 days (AM3 and AF3), and from 343 days (AM4 and AF4), respectively. Unirradiated mice served as control (UM and UF). The incidence of thymic lymphomas was about 60 % in AM1, AM2, AF1 and AF2, 40 % in AM3 and AF3 and 20 % in AF4 and AF4, demonstrating no sex dependency, but a distinct age dependency, for lymphomogenesis. It was proven that mice showed a tendency to become less susceptible to radiation induced thymic lymphoma with increasing age. Concomitantly, life-shortening also was caused, and the greater the degree of life-shortening was, the younger the mice were the start of exposure. Life-shortening was attributed to thymic lymphoma, and hemorrhage and infectious diseases due to the depletion of bone marrow cells. (author)

  5. Naltrexone at low doses upregulates a unique gene expression not seen with normal doses: Implications for its use in cancer therapy.

    Science.gov (United States)

    Liu, Wai M; Scott, Katherine A; Dennis, Jayne L; Kaminska, Elwira; Levett, Alan J; Dalgleish, Angus G

    2016-08-01

    It has been reported that lower doses of the opioid antagonist naltrexone are able to reduce tumour growth by interfering with cell signalling as well as by modifying the immune system. We have evaluated the gene expression profile of a cancer cell line after treatment with low-dose naltrexone (LDN), and assessed the effect that adapting treatment schedules with LDN may have on enhancing efficacy. LDN had a selective impact on genes involved with cell cycle regulation and immune modulation. Similarly, the pro-apoptotic genes BAD and BIK1 were increased only after LDN. Continuous treatment with LDN had little effect on growth in different cell lines; however, altering the treatment schedule to include a phase of culture in the absence of drug following an initial round of LDN treatment, resulted in enhanced cell killing. Furthermore, cells pre-treated with LDN were more sensitive to the cytotoxic effects of a number of common chemotherapy agents. For example, priming HCT116 with LDN before treatment with oxaliplatin significantly increased cell killing to 49±7.0 vs. 14±2.4% in cultures where priming was not used. Interestingly, priming with NTX before oxaliplatin resulted in just 32±1.8% cell killing. Our data support further the idea that LDN possesses anticancer activity, which can be improved by modifying the treatment schedule. PMID:27279602

  6. Effects of very low dose-rate 90Sr/90Y exposure on the acute moist desquamation response of pig skin

    International Nuclear Information System (INIS)

    Background and objectives: Previous data, predominantly involving high dose-rate fractionated irradiation with incomplete repair intervals, had indicated that the kinetics of repair of sublethal damage for acute radiation reactions in pig skin could best be defined by a biphasic repair model with half-times for repair of 0.2 and 5.4 h, partition coefficient 0.5. To further test the validity of this finding and obtain a better estimate of the repair rate of the slow component of repair, the acute response of pig skin to very low dose-rates (VLDR), originally estimated to be 0.0067-0.0244 Gy/min, was investigated as part of a 4 fraction irradiation protocol involving an overall treatment time of 90Sr/90Y plaques. Irradiation with a 4 fraction protocol included 3 equal, high dose-rate, fractions with full repair, followed by a fourth VLDR fraction. The total doses administered were originally planned to represent the dose associated with the predicted ED20, ED50 and ED80 (75% of total biological dose given at high dose-rate and 25% at VLDR) calculated on the basis of the repair kinetic parameters obtained from earlier studies. However, during the analysis a revision to the physical dosimetry was identified; this had been overlooked prior to the start of the study. Following completion of irradiation the irradiated sites were examined weekly and the presence or absence of moist desquamation recorded. Results: The incidence of moist desquamation was slightly higher than expected on the basis of the parameters used to calculate iso-effective doses, at least in part as a consequence of the change to the dosimetry. Using likelihood methods and the original dose estimates, the best model based estimate of the dose-rate correction factor for the LDR and VLDR plaques was 1.29. This was comparable with the physical calibration factor, median value 1.23. The VLDR fraction associated with a 50% incidence of moist desquamation, based on experimental observation, was 23.2 ± 0

  7. Total body irradiation (TBI) in pediatric patients. A single-center experience after 30 years of low-dose rate irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Linsenmeier, Claudia; Thoennessen, Daniel; Negretti, Laura; Streller, Tino; Luetolf, Urs Martin [University Hospital Zurich (Switzerland). Dept. of Radiation-Oncology; Bourquin, Jean-Pierre [University Children' s Hospital Zurich (Switzerland). Dept. of Hemato-Oncology; Oertel, Susanne [University Hospital Zurich (Switzerland). Dept. of Radiation-Oncology; Heidelberg Univ. (Germany). Dept. of Radiation Oncology

    2010-11-15

    TBI at the low-dose rate that was generally used here. Conditioning for bone marrow transplantation without radiation is an attractive option, but is not sufficiently effective to completely replace TBI for the most common pediatric indications. (orig.)

  8. Total body irradiation (TBI) in pediatric patients. A single-center experience after 30 years of low-dose rate irradiation

    International Nuclear Information System (INIS)

    TBI at the low-dose rate that was generally used here. Conditioning for bone marrow transplantation without radiation is an attractive option, but is not sufficiently effective to completely replace TBI for the most common pediatric indications. (orig.)

  9. Radiochemotherapy with short daily infusion of low-dose oxaliplatin, leucovorin, and 5-FU in T3-T4 unresectable rectal cancer: a phase II IATTGI study

    International Nuclear Information System (INIS)

    survival was 19.5 months (CI 95%, 18.0, 21). Conclusions: Outpatient treatment with low-dose, 30-min daily OXA infusion was feasible and very active, with acceptable toxicity

  10. [{sup 131}I]Iodoazomycin arabinoside for low-dose-rate isotope radiotherapy: radiolabeling, stability, long-term whole-body clearance and radiation dosimetry estimates in mice

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Piyush [Department of Oncologic Imaging, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, T6G 2N8 (Canada); McQuarrie, Steven A. [Department of Oncologic Imaging, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, T6G 2N8 (Canada); Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, T6G 2N8 (Canada); Zhou, Aihya [Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, T6G 2N8 (Canada); McEwan, Alexander J.B. [Department of Oncologic Imaging, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, T6G 2N8 (Canada); Wiebe, Leonard I. [Department of Oncologic Imaging, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, T6G 2N8 (Canada) and Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, T6G 2N8 (Canada)]. E-mail: leonard.wiebe@ualberta.ca

    2005-08-01

    activities. Based on measured radioactivity burdens during the week following injection and on published animal ([{sup 125}I]IAZA) and clinical ([{sup 123}I]IAZA) dosimetry data, the current dose estimates point to selective tumor irradiation at low dose rates.

  11. BrachyView: Proof-of-principle of a novel in-body gamma camera for low dose-rate prostate brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Petasecca, M.; Loo, K. J.; Safavi-Naeini, M.; Han, Z.; Metcalfe, P. E.; Lerch, M. L. F.; Qi, Y.; Rosenfeld, A. B. [Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522 (Australia); Meikle, S. [Brain and Mind Research Institute, University of Sydney, NSW 2006, Australia and Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522 (Australia); Pospisil, S.; Jakubek, J. [Institute of Experimental and Applied Physics, Czech Technical University of Prague, Prague (Czech Republic); Bucci, J. A. [St George Cancer Care Centre, St George Hospital, Kogarah, NSW 2217 (Australia); Zaider, M. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York 10021 (United States)

    2013-04-15

    Purpose: The conformity of the achieved dose distribution to the treatment plan strongly correlates with the accuracy of seed implantation in a prostate brachytherapy treatment procedure. Incorrect seed placement leads to both short and long term complications, including urethral and rectal toxicity. The authors present BrachyView, a novel concept of a fast intraoperative treatment planning system, to provide real-time seed placement information based on in-body gamma camera data. BrachyView combines the high spatial resolution of a pixellated silicon detector (Medipix2) with the volumetric information acquired by a transrectal ultrasound (TRUS). The two systems will be embedded in the same probe so as to provide anatomically correct seed positions for intraoperative planning and postimplant dosimetry. Dosimetric calculations are based on the TG-43 method using the real position of the seeds. The purpose of this paper is to demonstrate the feasibility of BrachyView using the Medipix2 pixel detector and a pinhole collimator to reconstruct the real-time 3D position of low dose-rate brachytherapy seeds in a phantom. Methods: BrachyView incorporates three Medipix2 detectors coupled to a multipinhole collimator. Three-dimensionally triangulated seed positions from multiple planar images are used to determine the seed placement in a PMMA prostate phantom in real time. MATLAB codes were used to test the reconstruction method and to optimize the device geometry. Results: The results presented in this paper show a 3D position reconstruction accuracy of the seed in the range of 0.5-3 mm for a 10-60 mm seed-to-detector distance interval (Z direction), respectively. The BrachyView system also demonstrates a spatial resolution of 0.25 mm in the XY plane for sources at 10 mm distance from Medipix2 detector plane, comparable to the theoretical value calculated for an equivalent gamma camera arrangement. The authors successfully demonstrated the capability of BrachyView for real

  12. Low dose effects. Adaptive response

    International Nuclear Information System (INIS)

    The purpose of this work was to evaluate if there are disturbancies in adaptive response when lymphocytes of people living on the polluted with radionuclides area after Chernobyl disaster and liquidators suffered from accident have been investigated. The level of lymphocytes with micronuclei have been scored in Moscow donors and people living in Bryansk region with the degree of contamination 15 - 40 Ci/km. The doses that liquidators have been obtained were not higher then 25 cGy. The mean spontaneous level of MN in control people and people from Chernobyl zones does't differ significantly but the individual variability in the mean value between two populations does not differ significantly too. And in this case it seems that persons of exposed areas. Then another important fact in lymphocytes of people living on polluted areas the chronic low dose irradiation does not induce the adaptive response. In Moscow people in most cases (≅ 59 %) the adaptive response is observed and in some cases the demonstration of adaptive response is not significant (≅1%). In Chernobyl population exposed to chronic low level, low dose rate irradiation there are fewer people here with distinct adaptive response (≅38%). And there appear beings with increased radiosensitivity after conditioned dose. Such population with enhanced radiosensitivity have not observed in Moscow. In liquidators the same types of effects have been registered. These results have been obtained on adults. Adaptive response in children 8 - 14 old population living in Moscow and in Chernobyl zone have been investigated too. In this case the spontaneous level of MN is higher in children living in polluted areas, after the 1.0 Gy irradiation the individual variability is very large. Only 5 % of children have distinct is very large. Only 5 % of children have distinct adaptive response, the enhancement of radiosensitivity after conditioned dose is observed. (authors)

  13. Asbestos Surveillance Program Aachen (ASPA): initial results from baseline screening for lung cancer in asbestos-exposed high-risk individuals using low-dose multidetector-row CT

    International Nuclear Information System (INIS)

    The purpose of this study was to assess the prevalence of lung cancer in a high-risk asbestos-exposed cohort using low-dose MDCT. Of a population of 5,389 former power-plant workers, 316 were characterized as individuals at highest risk for lung cancer according to a lung-cancer risk model including age, asbestos exposure and smoking habits. Of these 316, 187 (mean age: 66.6 years) individuals were included in a prospective trial. Mean asbestos exposure time was 29.65 years and 89% were smokers. Screening was performed on a 16-slice MDCT (Siemens) with low-dose technique (10/20 mAseff.; 1 mm/0.5 mm increment). In addition to soft copy PACS reading analysis on a workstation with a dedicated lung analysis software (LungCARE; Siemens) was performed. One strongly suspicious mass and eight cases of histologically proven lung cancer were found plus 491 additional pulmonary nodules (average volume: 40.72 ml, average diameter 4.62 mm). Asbestos-related changes (pleural plaques, fibrosis) were visible in 80 individuals. Lung cancer screening in this high-risk cohort showed a prevalence of lung cancer of 4.28% (8/187) at baseline screening with an additional large number of indeterminate pulmonary nodules. Low-dose MDCT proved to be feasible in this highly selected population. (orig.)

  14. Early effects comparison of X-rays delivered at high-dose-rate pulses by a plasma focus device and at low dose rate on human tumour cells.

    Science.gov (United States)

    Virelli, A; Zironi, I; Pasi, F; Ceccolini, E; Nano, R; Facoetti, A; Gavoçi, E; Fiore, M R; Rocchi, F; Mostacci, D; Cucchi, G; Castellani, G; Sumini, M; Orecchia, R

    2015-09-01

    A comparative study has been performed on the effects of high-dose-rate (DR) X-ray beams produced by a plasma focus device (PFMA-3), to exploit its potential medical applications (e.g. radiotherapy), and low-DR X-ray beams produced by a conventional source (XRT). Experiments have been performed at 0.5 and 2 Gy doses on a human glioblastoma cell line (T98G). Cell proliferation rate and potassium outward currents (IK) have been investigated by time lapse imaging and patch clamp recordings. The results showed that PFMA-3 irradiation has a greater capability to reduce the proliferation rate activity with respect to XRT, while it does not affect IK of T98G cells at any of the dose levels tested. XRT irradiation significantly reduces the mean IK amplitude of T98G cells only at 0.5 Gy. This work confirms that the DR, and therefore the source of radiation, is crucial for the planning and optimisation of radiotherapy applications.

  15. Low-dose non-enhanced CT versus full-dose contrast-enhanced CT in integrated PET/CT studies for the diagnosis of uterine cancer recurrence

    Energy Technology Data Exchange (ETDEWEB)

    Kitajima, Kazuhiro [Institute of Biomedical Research and Innovation, Department of PET Diagnosis, Kobe (Japan); Kobe University Graduate School of Medicine, Department of Radiology, Kobe (Japan); Suzuki, Kayo [Institute of Biomedical Research and Innovation, Department of PET Diagnosis, Kobe (Japan); Nakamoto, Yuji [Kyoto University Hospital, Department of Diagnostic Radiology, Kyoto (Japan); Onishi, Yumiko; Sakamoto, Setsu; Sugimura, Kazuro [Kobe University Graduate School of Medicine, Department of Radiology, Kobe (Japan); Senda, Michio [Institute of Biomedical Research and Innovation, Department of Molecular Imaging, Kobe (Japan); Kita, Masato [Kobe City Medical Center General Hospital, Department of Obstetrics and Gynecology, Kobe (Japan)

    2010-08-15

    To evaluate low-dose non-enhanced CT (ldCT) and full-dose contrast-enhanced CT (ceCT) in integrated {sup 18}F-fluorodeoxyglucose (FDG) PET/CT studies for restaging of uterine cancer. A group of 100 women who had undergone treatment for uterine cervical (n=55) or endometrial cancer (n=45) underwent a conventional PET/CT scans with ldCT, and then a ceCT scan. Two observers retrospectively reviewed and interpreted the PET/ldCT and PET/ceCT images in consensus using a three-point grading scale (negative, equivocal, or positive) per patient and per lesion. Final diagnoses were obtained by histopathological examination, or clinical follow-up for at least 6 months. Patient-based analysis showed that the sensitivity, specificity and accuracy of PET/ceCT were 90% (27/30), 97% (68/70) and 95% (95/100), respectively, whereas those of PET/ldCT were 83% (25/30), 94% (66/70) and 91% (91/100), respectively. Sensitivity, specificity and accuracy did not significantly differ between two methods (McNemar test, p=0.48, p=0.48, and p=0.13, respectively). There were 52 sites of lesion recurrence: 12 pelvic lymph node (LN), 11 local recurrence, 8 peritoneum, 7 abdominal LN, 5 lung, 3 supraclavicular LN, 3 liver, 2 mediastinal LN, and 1 muscle and bone. The grading results for the 52 sites of recurrence were: negative 5, equivocal 0 and positive 47 for PET/ceCT, and negative 5, equivocal 4 and positive 43 for PET/ldCT, respectively. Four equivocal regions by PET/ldCT (local recurrence, pelvic LN metastasis, liver metastasis and muscle metastasis) were correctly interpreted as positive by PET/ceCT. PET/ceCT is an accurate imaging modality for the assessment of uterine cancer recurrence. Its use reduces the frequency of equivocal interpretations. (orig.)

  16. The feasibility and safety of high-intensity focused ultrasound combined with low-dose external beam radiotherapy as supplemental therapy for advanced prostate cancer following hormonal therapy

    Institute of Scientific and Technical Information of China (English)

    Rui-Yi Wu; Guo-Min Wang; Lei Xu; Bo-Heng Zhang; Ye-Qing Xu; Zhao-Chong Zeng; Bing Chen

    2011-01-01

    The aim of this study was to investigate the feasibility and safety of high-intensity focused ultrasound (HIFU) combined with (+) low-dose external beam radiotherapy (LRT) as supplemental therapy for advanced prostate cancer (PCa) following hormonal therapy (HT). Our definition of HIFU+LRT refers to treating primary tumour lesions with HIFU in place of reduced field boost irradiation to the prostate, while retaining four-field box irradiation to the pelvis in conventional-dose external beam radiotherapy (CRT). We performed a prospective, controlled and non-randomized study on 120 patients with advanced PCa after HT who received HIFU, CRT, HIFU+LRT and HT alone, respectively. CT/MR imaging showed the primary tumours and pelvic lymph node metastases visibly shrank or even disappeared after HIFU+LRT treatment. There were significant differences among four groups with regard to overall survival (OS) and disease-specific survival (DSS) curves (P=0.018 and 0.015). Further comparison between each pair of groups suggested that the long-term DSS of the HIFU+LRT group was higher than those of the other three groups, but there was no significant difference between the HIFU+LRT group and the CRT group. Multivariable Cox's proportional hazard model showed that both HIFU+LRT and CRT were independently associated with DSS (P=0.001 and 0.035) and had protective effects with regard to the risk of death. Compared with CRT, HIFU+LRT significantly decreased incidences of radiation-related late gastrointestinal (GI) and genitourinary (GU) toxicity grade ≥II. In conclusion, long-term survival of patients with advanced PCa benefited from strengthening local control of primary tumour and regional lymph node metastases after HT. As an alternative to CRT, HIFU+LRT showed good efficacy and better safety.

  17. Role of low-dose spiral CT scan in early lung cancer screeing of high risk population: a systematic review of the literature with a Meta-analysis

    International Nuclear Information System (INIS)

    Objective: To assess the overall diagnostic value of low-dose spiral computed tomography (LDSCT) screening trials for early lung cancer of high risk population. Methods: A search in PubMed, Cancerlit, Embase bank, Cochrane Library, CBMdisc and CNKI was performed to identify relevant English and Chinese-language articles from January 1, 1995 to June 1,2005. Quality evaluation and heterogeneity test were performed to the included researches. Consistency analysis was executed. Pooled weighted sensitivity and specificity were calculated. Receiver operating characteristic (ROC) curve was performed and area under the curve (AUC) was calculated. Test of odds ratio(OR)was performed to these results of base screening and annual follow-up screening at least two years. Finally, sensitivity analysis was performed. Results: Fifteen articles were included, with 9 independent researches and a total of 8168 subjects. Heterogeneity existed. Base screening was undertaken in high risk population in the grade of BO (discovering nodule), B5 (discovering nodule of diameter more than 5 mm), B10 (discovering nodule of diameter more than 10 mm) and corresponding Kappa value was 0.061, 0.134 and 0.460, pooled weighted sensitivity was 0.686, 0.721 and 0.640, pooled weighted specificity was 0.708, 0.815 and 0.959. Area under the ROC was 0.778, 0.949 and 0.539 respectively. Statistically significant difference did not exist between the AUC of BO and B5 (P>0.05), but existed between B0 and B10, B5 and B10 (P<0.05). With the fixed effect model, the pooled OR in the grade of B5 and B10 were 1.11 and 1.66 respectively. Conclusion: The articles entered into this Meta-analysis were of high quality. The pooled weighted sensitivity and specificity of LDSCT screening for early lung cancer of high risk population was moderate. The method was affected by chance factors easily. It was relatively reasonable to define the positive standard as the discovered nodule's diameter was more than 5 mm. Close flow

  18. Effects of low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Several groups of human have been irradiated by accidental or medical exposure, if no gene defect has been associated to these exposures, some radioinduced cancers interesting several organs are observed among persons exposed over 100 to 200 mSv delivered at high dose rate. Numerous steps are now identified between the initial energy deposit in tissue and the aberrations of cell that lead to tumors but the sequence of events and the specific character of some of them are the subject of controversy. The stake of this controversy is the risk assessment. From the hypothesis called linear relationship without threshold is developed an approach that leads to predict cancers at any tiny dose without real scientific foundation. The nature and the intensity of biological effects depend on the quantity of energy absorbed in tissue and the modality of its distribution in space and time. The probability to reach a target (a gene) associated to the cancerating of tissue is directly proportional to the dose without any other threshold than the quantity of energy necessary to the effect, its probability of effect can be a more complex function and depends on the quality of the damage produced as well as the ability of the cell to repair the damage. These two parameters are influenced by the concentration of initial injuries in the target so by the quality of radiation and by the dose rate. The mechanisms of defence explain the low efficiency of radiation as carcinogen and then the linearity of effects in the area of low doses is certainly the least defensible scientific hypothesis for the prediction of the risks. (N.C.)

  19. Breast Cancer Rates by State

    Science.gov (United States)

    ... Associated Lung Ovarian Prostate Skin Uterine Cancer Home Breast Cancer Rates by State Language: English Español (Spanish) Recommend ... from breast cancer each year. Rates of Getting Breast Cancer by State The number of people who get ...

  20. Patterns of Recurrence After Low-Dose-Rate Prostate Brachytherapy: A Population-Based Study of 2223 Consecutive Low- and Intermediate-Risk Patients

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Andrea C.; Morris, W. James, E-mail: JMorris@bccancer.bc.ca; Pickles, Tom; Keyes, Mira; McKenzie, Michael; Tyldesley, Scott

    2015-03-15

    Objectives: This study examined patterns of recurrence after low–dose-rate prostate brachytherapy (LDR-PB), estimated local recurrence rate and compared that rate to the estimated local recurrence rate after radical prostatectomy (RP). Methods and Materials: A prospective database was maintained with clinical, dosimetric, and outcome data for all LDR-PB implantation procedures performed at our institution. From 1998 to 2008, 2223 patients with prostate cancer received LDR-PB without supplemental external beam radiation therapy. Patients who developed Phoenix-defined biochemical failure were reviewed for sites of relapse and investigations completed. Results: At a median follow-up of 5 years, 108 of 2223 patients (4.8%) developed biochemical relapse. In 1 additional patient, local relapse was found on transurethral prostate resection, but his prostate-specific antigen concentration was well short of triggering Phoenix-defined failure. Of the 109 patients with disease relapse, 18 of 2223 (0.8%) had a proven local recurrence, and 30 of 2223 (1.3%) had a proven distant recurrence. The remaining 61 of 2223 patients (2.7%) had unidentified sites of recurrence; of these, 57 patients (93%) had digital rectal examinations (DREs), 18 (30%) had post-treatment biopsies, 45 (74%) had bone scans, and 34 (56%) had computed tomography imaging of the abdomen and pelvis. If every biochemical failure were local, the local recurrence rate would be as high as 4.9%; however, by excluding those with proven distant failure and those with both a negative DRE and biopsy, we estimate that the local recurrence rate is 2.7% or less. Conclusions: In the context of limitations of the study design, our population-based analysis indicates that the local recurrence rate after LDR-PB is as low or lower than that after RP in our jurisdiction.

  1. New risk estimates at low doses

    International Nuclear Information System (INIS)

    The age of molecular radiation epidemiology may be at hand. The techniques are available to establish with the degree of precision required to determine whether agent-specific mutations can be identified consistently. A concerted effort to examine radiation-induced changes in as many relevant genes as possible appears to be justified. Cancers in those exposed to low doses of ionizing radiation should be chosen for the investigation. Parallel studies of radiation-induced cancers in experimental animals would not only complement the human studies, but perhaps reveal approaches to extrapolation of risk estimates across species. A caveat should be added to this optimistic view of what molecular studies might contribute to the knotty problem of risk estimates at low doses. The suggestions are made by one with no expertise in the field of molecular biology

  2. Does the cell radioresistance acquired by low dose-rate gamma irradiation depend on genetic factors or physiological changes. Study carried out on inactive cells of the unicellular green alga Chlorella pyrenoidosa CHICK

    International Nuclear Information System (INIS)

    Inactive cells of the unicellular green alga Chlorella pyrenoidosa CHICK were used to test the following hypothesis: the radioresistance acquired by these cells after irradiation at low dose rate (0.06 Gy/mn) is due to the selection or induction of radioresistant clones. Clone cultures were grown mainly from colonies exhibiting defects (high cell loss, slowed growth, pigment deficiency). Of thirty clones studied, three only of second and third separations possessed the radioresistance of their original population. On the basis of these results, backed up by a first experiment which shows the loss of cell radioresistance when continuous irradiation is stopped, the initial hypothesis may be dismissed and research directed towards changes relative to cell restoration processes by irradiation at low dose rates

  3. The 20th L H Gray Conference - Radiation Cancer Analysis and Low Dose Risk Assessment: New Developments and Perspectives (Ede, the Netherlands, February 2002)

    International Nuclear Information System (INIS)

    There are few international venues where scientists in vastly different fields working on a common problem, or on a number of closely related problems, can get together in an intimate setting to present the results of their research and to discuss their approaches and views in a collegial atmosphere, and without the trappings of a huge convention with its conflicting parallel sessions and distracting events. Over the years, the L H Gray Conferences have provided an ideal setting for such intimate gatherings. This year the 20th L H Gray Conference, held in Ede, the Netherlands, was no exception. Convened for the first time outside the United Kingdom and hosted by the Dutch National Institute for Public Health and the Environment (RIVM). Paramount in all the participants' minds was the emerging information from molecular radiation biology on the recently recognised 'new' processes such as genomic instability, bystander effects, hypersensitivity, and the adaptive response. A novel aspect this year was the introduction of the opportunity, both at the beginning and at the end of the meeting, to participate in a 'vote' on controversial subjects by answering electronically such questions as: 'does radiation hormesis occur at low doses?' and 'should an age-dependence of radiological risk be incorporated into recommendations for radiation protectionThere appears to be no evidence for radiation-induced genomic instability, at least in this tumour. If this model holds for other tumour types, it would suggest that there is no 'radiation fingerprint' and that no special mechanism lies behind radiation-induced cancer. The major social event of the meeting was an afternoon devoted to a delightful excursion to the renowned Kroeller-Mueller Museum in the nearby national park (De Hoge Veluwe). Our Dutch hosts were even able to order up some sunshine for the day. After an afternoon of strolling through the museum and surrounding park, we were bussed to a hotel on the precipitous

  4. EFFECT OF LOW DOSES OF THE MYCOTOXIN FUMONISIN B1 ON THE BODY MASS GAIN, FEED INTAKE AND FEED CONVERSION RATE OF PIGS

    Directory of Open Access Journals (Sweden)

    Akos Toth

    2000-06-01

    Full Text Available The fumonisin group of mycotoxins produced by Fusariun moniliforme is a rather newly discovered contaminant of some agricultural products, especially maize based food and animal feed. Fumonisin was discovered in 1988 of mouldy maize inspected since 1993 has shown FB1 contamination, the degree of this contamination increasing from year to year. Problems of mycotoxins cause significant economic losses due to the reduced feed intake, body weight gain and feed efficiency. We have very few informations about the effect of FB1 on these in South Africa, where high evidence was found between the occurrence of human oesophageal cancer and the rate of FB1 contamination. The discovery of this toxin lead to the explanation of equine leucoencephalomalacia (ELEM, porcine pulmonary oedema (PPC and possibly liver cancer in rats. In Hungary almost 70 % parameters – especially in farm animals. Three experiments were carried out with weaned piglets, in order to study the dose and time dependent effect of FB1. Fungal culture of Fusariun moniliforme was added to the diet so that the FB1 exposure was: 0, 10, 20 and 40 ppm for 4 weeks, 0, 1, 5 and 10 ppm for 8 weeks and 0, 1, 5 and 10 ppm for 5 months. In none of the experiments and the periods examined had FB1 any significant effect on feed consumption, body weight gain and feed conversion of weaned pigs. In spite of these findings mild or severe pulmonary oedema caused by the toxin was found in the animals by dissection carried out at the end of the experiment. Our results draw the attention to human health concerns of FB1. The toxin consumed by the animals without any clinical signs can cumulate in the animals and then enter the human organism by means of products of animal origin (meat, milk, etc..

  5. Lung Cancer Rates by State

    Science.gov (United States)

    ... HPV-Associated Ovarian Prostate Skin Uterine Cancer Home Lung Cancer Rates by State Language: English Español (Spanish) Recommend ... incidence data are currently available. Rates of Getting Lung Cancer by State The number of people who get ...

  6. Harderian Gland Tumorigenesis: Low-Dose and LET Response.

    Science.gov (United States)

    Chang, Polly Y; Cucinotta, Francis A; Bjornstad, Kathleen A; Bakke, James; Rosen, Chris J; Du, Nicholas; Fairchild, David G; Cacao, Eliedonna; Blakely, Eleanor A

    2016-05-01

    Increased cancer risk remains a primary concern for travel into deep space and may preclude manned missions to Mars due to large uncertainties that currently exist in estimating cancer risk from the spectrum of radiations found in space with the very limited available human epidemiological radiation-induced cancer data. Existing data on human risk of cancer from X-ray and gamma-ray exposure must be scaled to the many types and fluences of radiations found in space using radiation quality factors and dose-rate modification factors, and assuming linearity of response since the shapes of the dose responses at low doses below 100 mSv are unknown. The goal of this work was to reduce uncertainties in the relative biological effect (RBE) and linear energy transfer (LET) relationship for space-relevant doses of charged-particle radiation-induced carcinogenesis. The historical data from the studies of Fry et al. and Alpen et al. for Harderian gland (HG) tumors in the female CB6F1 strain of mouse represent the most complete set of experimental observations, including dose dependence, available on a specific radiation-induced tumor in an experimental animal using heavy ion beams that are found in the cosmic radiation spectrum. However, these data lack complete information on low-dose responses below 0.1 Gy, and for chronic low-dose-rate exposures, and there are gaps in the LET region between 25 and 190 keV/μm. In this study, we used the historical HG tumorigenesis data as reference, and obtained HG tumor data for 260 MeV/u silicon (LET ∼70 keV/μm) and 1,000 MeV/u titanium (LET ∼100 keV/μm) to fill existing gaps of data in this LET range to improve our understanding of the dose-response curve at low doses, to test for deviations from linearity and to provide RBE estimates. Animals were also exposed to five daily fractions of 0.026 or 0.052 Gy of 1,000 MeV/u titanium ions to simulate chronic exposure, and HG tumorigenesis from this fractionated study were compared to the

  7. Harderian Gland Tumorigenesis: Low-Dose and LET Response.

    Science.gov (United States)

    Chang, Polly Y; Cucinotta, Francis A; Bjornstad, Kathleen A; Bakke, James; Rosen, Chris J; Du, Nicholas; Fairchild, David G; Cacao, Eliedonna; Blakely, Eleanor A

    2016-05-01

    Increased cancer risk remains a primary concern for travel into deep space and may preclude manned missions to Mars due to large uncertainties that currently exist in estimating cancer risk from the spectrum of radiations found in space with the very limited available human epidemiological radiation-induced cancer data. Existing data on human risk of cancer from X-ray and gamma-ray exposure must be scaled to the many types and fluences of radiations found in space using radiation quality factors and dose-rate modification factors, and assuming linearity of response since the shapes of the dose responses at low doses below 100 mSv are unknown. The goal of this work was to reduce uncertainties in the relative biological effect (RBE) and linear energy transfer (LET) relationship for space-relevant doses of charged-particle radiation-induced carcinogenesis. The historical data from the studies of Fry et al. and Alpen et al. for Harderian gland (HG) tumors in the female CB6F1 strain of mouse represent the most complete set of experimental observations, including dose dependence, available on a specific radiation-induced tumor in an experimental animal using heavy ion beams that are found in the cosmic radiation spectrum. However, these data lack complete information on low-dose responses below 0.1 Gy, and for chronic low-dose-rate exposures, and there are gaps in the LET region between 25 and 190 keV/μm. In this study, we used the historical HG tumorigenesis data as reference, and obtained HG tumor data for 260 MeV/u silicon (LET ∼70 keV/μm) and 1,000 MeV/u titanium (LET ∼100 keV/μm) to fill existing gaps of data in this LET range to improve our understanding of the dose-response curve at low doses, to test for deviations from linearity and to provide RBE estimates. Animals were also exposed to five daily fractions of 0.026 or 0.052 Gy of 1,000 MeV/u titanium ions to simulate chronic exposure, and HG tumorigenesis from this fractionated study were compared to the

  8. Radon Exposure and the Definition of Low Doses-The Problem of Spatial Dose Distribution.

    Science.gov (United States)

    Madas, Balázs G

    2016-07-01

    Investigating the health effects of low doses of ionizing radiation is considered to be one of the most important fields in radiological protection research. Although the definition of low dose given by a dose range seems to be clear, it leaves some open questions. For example, the time frame and the target volume in which absorbed dose is measured have to be defined. While dose rate is considered in the current system of radiological protection, the same cancer risk is associated with all exposures, resulting in a given amount of energy absorbed by a single target cell or distributed among all the target cells of a given organ. However, the biological effects and so the health consequences of these extreme exposure scenarios are unlikely to be the same. Due to the heterogeneous deposition of radon progeny within the lungs, heterogeneous radiation exposure becomes a practical issue in radiological protection. While the macroscopic dose is still within the low dose range, local tissue doses on the order of Grays can be reached in the most exposed parts of the bronchial airways. It can be concluded that progress in low dose research needs not only low dose but also high dose experiments where small parts of a biological sample receive doses on the order of Grays, while the average dose over the whole sample remains low. A narrow interpretation of low dose research might exclude investigations with high relevance to radiological protection. Therefore, studies important to radiological protection should be performed in the frame of low dose research even if the applied doses do not fit in the dose range used for the definition of low doses. PMID:27218294

  9. High dose rate brachytherapy for oral cancer

    International Nuclear Information System (INIS)

    Brachytherapy results in better dose distribution compared with other treatments because of steep dose reduction in the surrounding normal tissues. Excellent local control rates and acceptable side effects have been demonstrated with brachytherapy as a sole treatment modality, a postoperative method, and a method of reirradiation. Low-dose-rate (LDR) brachytherapy has been employed worldwide for its superior outcome. With the advent of technology, high-dose-rate (HDR) brachytherapy has enabled health care providers to avoid radiation exposure. This therapy has been used for treating many types of cancer such as gynecological cancer, breast cancer, and prostate cancer. However, LDR and pulsed-dose-rate interstitial brachytherapies have been mainstays for head and neck cancer. HDR brachytherapy has not become widely used in the radiotherapy community for treating head and neck cancer because of lack of experience and biological concerns. On the other hand, because HDR brachytherapy is less time-consuming, treatment can occasionally be administered on an outpatient basis. For the convenience and safety of patients and medical staff, HDR brachytherapy should be explored. To enhance the role of this therapy in treatment of head and neck lesions, we have reviewed its outcomes with oral cancer, including Phase I/II to Phase III studies, evaluating this technique in terms of safety and efficacy. In particular, our studies have shown that superficial tumors can be treated using a non-invasive mold technique on an outpatient basis without adverse reactions. The next generation of image-guided brachytherapy using HDR has been discussed. In conclusion, although concrete evidence is yet to be produced with a sophisticated study in a reproducible manner, HDR brachytherapy remains an important option for treatment of oral cancer. (author)

  10. Dose to the Bladder Neck Is the Most Important Predictor for Acute and Late Toxicity After Low-Dose-Rate Prostate Brachytherapy: Implications for Establishing New Dose Constraints for Treatment Planning

    Energy Technology Data Exchange (ETDEWEB)

    Hathout, Lara; Folkert, Michael R.; Kollmeier, Marisa A.; Yamada, Yoshiya [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Cohen, Gil' ad N. [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Zelefsky, Michael J., E-mail: zelefskm@mskcc.org [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States)

    2014-10-01

    Purpose: To identify an anatomic structure predictive for acute (AUT) and late (LUT) urinary toxicity in patients with prostate cancer treated with low-dose-rate brachytherapy (LDR) with or without external beam radiation therapy (EBRT). Methods and Materials: From July 2002 to January 2013, 927 patients with prostate cancer (median age, 66 years) underwent LDR brachytherapy with Iodine 125 (n=753) or Palladium 103 (n=174) as definitive treatment (n=478) and as a boost (n=449) followed by supplemental EBRT (median dose, 50.4 Gy). Structures contoured on the computed tomographic (CT) scan on day 0 after implantation included prostate, urethra, bladder, and the bladder neck, defined as 5 mm around the urethra between the catheter balloon and the prostatic urethra. AUT and LUT were assessed with the Common Terminology Criteria for Adverse Events, version4. Clinical and dosimetric factors associated with AUT and LUT were analyzed with Cox regression and receiver operating characteristic analysis to calculate area under the receiver operator curve (ROC) (AUC). Results: Grade ≥2 AUT and grade ≥2 LUT occurred in 520 patients (56%) and 154 patients (20%), respectively. No grade 4 toxicities were observed. Bladder neck D2cc retained a significant association with AUT (hazard ratio [HR], 1.03; 95% confidence interval [CI], 1.03-1.04; P<.0001) and LUT (HR, 1.01; 95% CI, 1.00-1.03; P=.014) on multivariable analysis. In a comparison of bladder neck with the standard dosimetric variables by use of ROC analysis (prostate V100 >90%, D90 >100%, V150 >60%, urethra D20 >130%), bladder neck D2cc >50% was shown to have the strongest prognostic power for AUT (AUC, 0.697; P<.0001) and LUT (AUC, 0.620; P<.001). Conclusions: Bladder neck D2cc >50% was the strongest predictor for grade ≥2 AUT and LUT in patients treated with LDR brachytherapy. These data support inclusion of bladder neck constraints into brachytherapy planning to decrease urinary toxicity.

  11. Investigating the influence of drug aggregation on the percutaneous penetration rate of tetracaine when applying low doses of the agent topically to the skin.

    Science.gov (United States)

    Cai, X J; Patel, T; Woods, A; Mesquida, P; Jones, S A

    2016-04-11

    Understanding the molecular aggregation of therapeutic agents is particularly important when applying low doses of a drug to the surface of the skin. The aim of this study was to understand how the concentration of a drug influenced its molecular aggregation and its subsequent percutaneous penetration after topical application. A model drug tetracaine was shown to form a series of different aggregates across the μM (fluorescence spectroscopy) to mM (light scattering analysis) concentration range. The aggregate formation process was sensitive to the pH of the vehicle in which the drug was dissolved (pH 4, critical aggregation concentration (CAC) - 11μM; pH 8, CAC - 7μM) and it appeared to have an impact upon the drug's percutaneous penetration. At pH 4, increasing the concentration of the drug in the donor solution decreased the skin permeability coefficient (Kp) of tetracaine (13.7±4.3×10(-3)cm/h to0.06±0.02×10(-3)cm/h), whilst at pH 8, it increased the Kp (29.9±9.9×10(-3)cm/h to 75.1±41.7×10(-3)cm/h). These data trends were reproduced in a silicone membrane and this supported the notion that the more polar aggregates formed at pH 4 acted to decrease the proportion of species available to pass through the skin, whilst the more hydrophobic aggregates formed in pH 8 increased the membrane diffusing species. PMID:26854427

  12. 小剂量氯胺酮辅助芬太尼静脉自控镇痛用于晚期癌痛治疗%PCIA with low dose Ketamine combined with Fentanyl for treatment of terminal cancer pain

    Institute of Scientific and Technical Information of China (English)

    邹尧铨; 陈东生

    2012-01-01

    Objective To observe the analgesic effect of patient control intravenous analgesia ( PCIA) with low-dose Ketamine and Fentanyl for terminal cancer pain patients. Methods 49 patients with moderate to severe terminal cancer pain were randomly di vided into two groups. They were treated with Fentanyl 0. 3 (μg/(kg · h) (groupl) orFentanyl 0.2 μg/(kg · h) + Ketamine 70 μg/( kg · h) (group II ) . Ondansetron ( Zudan) 16 mg and Droperido] lOmg were added into each treatment. The mixed liquid was diluted to 100ml with physiological saline. The visual analogue scale ( VAS) of pain scores and the rate of side effects were evaluated at 2 , 24 and 48h after analgesic pump was used. Results The degrees of pain in both groups were largely alleviated. Compared with group I , the pain score of group II at each time point was significantly lower ( P < 0.01) , and the times of pressing of PCI A and dosage of Fentanyl in group II were less (P <0. 01). The incidences of nausea, vomiting and constipation in group I were higher than those in group H . There was no difference in the incidences of skin itch, respiration depression and hallucination between two groups. The patients' life satisfactory rate in group II was obviously higher than that in group I . Conclusion PCIA with low-dose Ketamine and Fentanyl for terminal cancer pain patients has the good analgesic effect and fewer side effects.%目的 观察小剂量氯胺酮辅助芬太尼静脉自控镇痛(PCIA)用于晚期癌痛患者的止痛效果.方法 选择49例中、重度晚期癌痛病人,随机分成两组,均以镇痛泵(1 ml/h)行静脉镇痛,Ⅰ组采用芬太尼0.3 μg/(kg·h),Ⅱ组用芬太尼0.2 μg/(kg·h)+氯胺酮70μg/(kg·h).每种配方中均加入恩丹西酮(枢丹)16 mg、氟哌啶10 mg,并用生理盐水将混合药液稀释至100 ml.分别在安装止痛泵后2、24、48 h采用视觉模拟评分法(VAS)评估疼痛程度,统计两组不良反应的发生率.结果 经治疗,两组病例疼痛基本

  13. Radioprotection of 1,2-dimethylhydrazine-initiated colon cancer in rats using low-dose γ rays by modulating multidrug resistance-1, cytokeratin 20, and β-catenin expression.

    Science.gov (United States)

    Nabil, H M; Hassan, B N; Tohamy, A A; Waaer, H F; Abdel Moneim, A E

    2016-03-01

    Ionizing radiation is a widely used therapy for solid tumors. However, high-dose ionizing radiation causes apoptosis, transforms normal cells into tumor cells, and impairs immune functions, leading to the defects in the removal of damaged or tumor cells. In contrast, low-dose radiation has been reported to exert various beneficial effects in cells. This experimental study investigated the effect of γ rays at low dose on the development of colorectal tumor in a 1,2-dimethylhydrazine (DMH)-induced colon cancer. Colorectal tumor model was induced in Wistar rats by subcutaneous injection of DMH (20 mg/kg) once a week for 15 weeks. Starting from zero day of DMH injection, a single low dose of whole-body γ irradiation of 0.5 Gy/week was applied to the rats. A significant reduction in lipid peroxidation, nitric oxide, and elevation in the glutathione content and antioxidant enzyme activity (superoxide dismutase and catalase) were observed after γ irradiation comparing with DMH group. Moreover, γ ray reduced the expressions of multidrug resistance 1 (MDR1), β-catenin, and cytokeratin 20 (CK20) those increased in DMH-treated rats. However, survivin did not change with γ ray treatment. A histopathological examination of the DMH-injected rats revealed ulcerative colitis, dysplasia, anaplasia, and hyperchromasia. An improvement in the histopathological picture was seen in the colon of rats exposed to γ rays. In conclusion, the present results showed that low-dose γ ray significantly inhibited DMH-induced colon carcinogenesis in rats by modulating CK20, MDR1, and β-catenin expression but not survivin expression.

  14. Association between absolute volumes of lung spared from low-dose irradiation and radiation-induced lung injury after intensity-modulated radiotherapy in lung cancer: a retrospective analysis

    OpenAIRE

    Chen, Jinmei; Hong, Jinsheng; Zou, Xi; Lv, Wenlong; Guo, Feibao; Hong, Hualan; Zhang, Weijian

    2015-01-01

    The aim of this study was to investigate the association between absolute volumes of lung spared from low-dose irradiation and radiation-induced lung injury (RILI) after intensity-modulated radiotherapy (IMRT) for lung cancer. The normal lung relative volumes receiving greater than 5, 10, 20 and 30 Gy (V5–30) mean lung dose (MLD), and absolute volumes spared from greater than 5, 10, 20 and 30 Gy (AVS5–30) for the bilateral and ipsilateral lungs of 83 patients were recorded. Any association of...

  15. Second-line treatment of non small cell lung cancer by biweekly gemcitabine and docetaxel +/- granulocyte-macrophage colony stimulating factor and low dose aldesleukine.

    Science.gov (United States)

    Correale, Pierpaolo; Tindara Miano, Salvatora; Remondo, Cinzia; Migali, Cristina; Rotundo, Maria Saveria; Macrì, Paolo; Tagliaferri, Pierosandro; Caraglia, Michele; Gotti, Giuseppe; Francini, Guido

    2009-03-15

    Background. The antitumor activity of a novel biweekly gemcitabine (G) + docetaxel (D) regimen +/- granulocyte-macrophage colony stimulating factor (GM-CSF) and aldesleukine (IL-2) has been evaluated in a phase II trial in advanced pretreated non-small-cell lung cancer (NSCLC). Results. The treatment was well tolerated. The 42.3% response rate exceeded the predefined target activity, while time to progression (TTP) and overall survival (OS) were 7 and 11.2 months, respectively. A greater objective response rate (58.3% vs 28.6%) and an increased number of eosinophils, basophils and activated mononuclear blood cells were observed in those patients who also received cytokine administration. Methods. Twenty-six NSCLC patients received second line G (1000 mg/m2) and D (75 mg/m2) every 15 days. 12/26 patients also received s.c. GM-CSF (100µg, days 2-6) and s.c. IL-2 (0.5MIU/ twice daily, days 7-14 and 16-29) by random selection. Conclusion. The biweekly GD regimen is a safe and active second-line treatment in NSCLC. Addition of immune-adjuvant cytokines' may enhance the activity of this therapeutic combination. PMID:19242101

  16. Enhancement of transformation rates in higher plants by low-dose irradiation: Are DNA repair systems involved in the incorporation of exogenous DNA into the plant genome?

    Science.gov (United States)

    Köhler, F; Cardon, G; Pöhlman, M; Gill, R; Schieder, O

    1989-02-01

    Irradiation (X-ray; 5-15 Gy) of protoplasts treated with plasmid-DNA and PEG yielded higher transformation rates in comparison to non-irradiated protoplasts transformed by the same method. This could be demonstrated for four plant species. The irradiation doses used did not affect the total number of colonies regenerated without selection pressure, but resulted in 3-6-fold enhancement of hygromycin- or kanamycin-resistant colonies. Plant regeneration frequencies of transformed colonies derived from irradiated and non-irradiated protoplasts were similar in tobacco as well as in Petunia. Higher integration rates of foreign DNA as a consequence of an increased recombination machinery in irradiated cells may be responsible for the enhancement of the number of stably transformed colonies.

  17. Effect of ultra-low-dose estriol and lactobacilli vaginal tablets (Gynoflor®) on inflammatory and infectious markers of the vaginal ecosystem in postmenopausal women with breast cancer on aromatase inhibitors.

    Science.gov (United States)

    Donders, G; Bellen, G; Neven, P; Grob, P; Prasauskas, V; Buchholz, S; Ortmann, O

    2015-10-01

    This study was a detailed microscopic analysis of the changes of vaginal microflora characteristics after application of 0.03 mg estriol-lactobacilli combination on the vaginal ecosystem in postmenopausal breast cancer (BC) survivors on aromatase inhibitors (AI) with severe atrophic vaginitis. A total of 16 BC women on AI applied daily one vaginal tablet of Gynoflor® for 28 days followed by a maintenance therapy of three tablets weekly for 8 weeks. During four follow up visits a smear from the upper lateral vaginal wall was analysed by phase contrast microscopy at 400 times magnification in order to classify the lactobacillary grades(LBG), bacterial vaginosis (BV), aerobic vaginitis (AV), vulvovaginal candidosis (VVC), proportional number of leukocytes and evidence of parabasal cells and epitheliolysis. LBG improved from 81% LBG-III at entry to 88% LBG-I&IIa after 2 weeks of initial therapy, which further improved upon follow up (p treatment (p < 0.01). While at entry most patients had moderate or severe AV, after maintenance therapy no patient except one had AV. The number of leukocytes dropped dramatically from a score of 1.78 ± 0.70 to 1.06 ± 0.25 which was consistent till the end of the study (p < 0.01). Parabasal cells dropped from a score of 3.4 ± 0.64 at entry to 1.3 ± 0.60 at the final visit (p trend < 0.01). Starting from a low rate of Candida colonisation of 2/14 (14%), a sudden rise to 7/16 (44%) occurred after 2 weeks, to return back to base levels at subsequent visits. The vaginal use of ultra-low dose estriol and lactobacilli results in rapid and enduring improvement of all markers of the vaginal microflora and epithelial vaginal cell quality in women with breast cancer on AI with dyspareunia. Candida may develop soon after its use, but rapidly disappears again upon their prolonged use. Due to its excellent safety profiles and clinical efficacy we recommend this product as first choice in women on AI with severe dyspareunia. PMID:26223323

  18. Alterations in p53-specific T cells and other lymphocyte subsets in breast cancer patients during vaccination with p53-peptide loaded dendritic cells and low-dose interleukin-2

    DEFF Research Database (Denmark)

    Svane, Inge Marie; Pedersen, Anders E; Nikolajsen, Kirsten;

    2008-01-01

    We have previously established a cancer vaccine using autologous DCs, generated by in vitro stimulation with IL-4 and GM-CSF, and pulsed with six HLA-A*0201 binding wild-type p53 derived peptides. This vaccine was used in combination with low-dose interleukin-2 in a recently published clinical...... Phase II trial where 26 HLA-A2+ patients with progressive late-stage metastatic breast cancer (BC) were included. Almost 1/3rd of the patients obtained stable disease or minor regression during treatment with a positive correlation to tumour over-expression of p53. In the present study, we performed...... a comprehensive analysis of the effector stage of the p53-specific CD8+ T cells by the use of Dextramer Technology and multicolour FACS. Pre- and post-treatment blood samples from eight BC patients were analysed. Independent of clinical outcome p53-specific T cells were phenotypic distinctly antigen experienced...

  19. [The functional state of the mitochondrial respiratory chain of the small intestine enterocytes of the rats under the low dose rate X-ray total external exposure].

    Science.gov (United States)

    2013-01-01

    The influence of the low-rate ionizing radiation (0.055 Gy/min) at the doses of 0.1; 0.5 and 1.0 Gy on the functional state of the mitochondria respiratory chain of the rat small intestine enterocytes was investigated. The dysfunction of the electron transport chain enzymes andchanges in the content of cytochromes b, c, a in themitochondrial inner membrane were revealed 1, 12 and 24 hours after exposure to radiation. The re- vealed disorders indicate early membrane sensitivity to the radiation effect. The inhibition of the H+ -ATPase activity in the studied dose range indicates the decrease of the mitochondrial energy capacity. PMID:25508872

  20. Pre-irradiation with low-dose 12C6+ beam significantly enhances the efficacy of AdCMV-p53 gene therapy in human non-small lung cancer

    Institute of Scientific and Technical Information of China (English)

    LIU Bing; DUAN Xin; ZHANG Hong; LI WenJian; LI Qiang; ZHOU GuangMing; XIE Yi; HAO JiFang; MIN FengLing; ZHOU QingMing

    2007-01-01

    The combination of ionizing radiation and gene therapy has been investigated. However, there are very few reports about the combination of heavy-ion irradiation and gene therapy. To determine if the pre-exposure to low-dose heavy ion beam enhances the suppression of AdCMV-p53 on non-small lung cancer (NSLC), the cells pre-irradiated or non-irradiated were infected with 20, 40 MOl of AdCMV-p53. Survival fraction and the relative biology effect (RBE) were determined by clonogenic assay. The results showed that the proportions of p53 positive cells in 12C6+ beam induced AdCMV-p53 infected cells were more than 90%, which were significantly more than those in γ-ray induced AdCMV-p53 infected cells. The pre-exposure to low-dose 12C6+ beam significantly prevented the G0/G1 arrest and activated G2/M checkpoints. The pre-exposure to 12C6+ beam significantly improved cell to apoptosis. RBEs for the 12C6+ + AdCMV-p53 infection groups were 30%-60%, 20% -130% and 30%-70% more than those for the 12C6+-irradiated only, AdCMV-p53 infected only, and γ-irradiation induced AdCMVp53 infected groups, respectively. The data suggested that the pre-exposure to low-dose 12C6+ beam significantly promotes exogenous p53 expression in NSLC, and the suppression of AdCMV-p53 gene therapy on NSLC.

  1. Pre-irradiation with low-dose 12C6+ beam significantly enhances the efficacy of AdCMV-p53 gene therapy in human non-small lung cancer

    Science.gov (United States)

    Liu, Bing; Zhang, Hong; Li, Wenjian; Li, Qiang; Zhou, Guangming; Xie, Yi; Hao, Jifang; Min, Fengling; Zhou, Qingming; Duan, Xin

    2007-04-01

    The combination of ionizing radiation and gene therapy has been investigated. However, there are very few reports about the combination of heavy-ion irradiation and gene therapy. To determine if the pre-exposure to low-dose heavy ion beam enhances the suppression of AdCMV-p53 on non-small lung cancer (NSLC), the cells pre-irradiated or non-irradiated were infected with 20, 40 MOI of AdCMV-p53. Survival fraction and the relative biology effect (RBE) were determined by clonogenic assay. The results showed that the proportions of p53 positive cells in 12C6+ beam induced AdCMV-p53 infected cells were more than 90%, which were significantly more than those in γ-ray induced AdCMV-p53 infected cells. The pre-exposure to low-dose 12C6+ beam significantly prevented the G0/G1 arrest and activated G2/M checkpoints. The pre-exposure to 12C6+ beam significantly improved cell to apoptosis. RBEs for the 12C6+ + AdCMV-p53 infection groups were 30% 60%, 20% 130% and 30% 70% more than those for the 12C6+-irradiated only, AdCMV-p53 infected only, and γ-irradiation induced AdCMVp53 infected groups, respectively. The data suggested that the pre-exposure to low-dose 12C6+ beam significantly promotes exogenous p53 expression in NSLC, and the suppression of AdCMV-p53 gene therapy on NSLC.

  2. Pre-irradiation with low-dose 12C6+beam significantly enhances the efficacy of AdCMV-p53 gene therapy in human non-small lung cancer

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The combination of ionizing radiation and gene therapy has been investigated. However, there are very few reports about the combination of heavy-ion irradiation and gene therapy. To determine if the pre-exposure to low-dose heavy ion beam enhances the suppression of AdCMV-p53 on non-small lung cancer (NSLC), the cells pre-irradiated or non-irradiated were infected with 20, 40 MOI of AdCMV-p53. Survival fraction and the relative biology effect (RBE) were determined by clonogenic assay. The results showed that the proportions of p53 positive cells in 12C6+ beam induced AdCMV-p53 infected cells were more than 90%, which were signifi-cantly more than those in γ-ray induced AdCMV-p53 infected cells. The pre-exposure to low-dose 12C6+ beam significantly prevented the G0/G1 arrest and activated G2/M checkpoints. The pre-exposure to 12C6+ beam significantly improved cell to apoptosis. RBEs for the 12C6+ + AdCMV-p53 infection groups were 30%-60%, 20%-130% and 30%-70% more than those for the 12C6+-irradiated only, AdCMV-p53 infected only, and γ-irradiation induced AdCMVp53 infected groups, respectively. The data suggested that the pre-exposure to low-dose 12C6+ beam significantly promotes exogenous p53 expression in NSLC, and the suppression of AdCMV-p53 gene therapy on NSLC.

  3. Intradermal vaccination of adults with three low doses (2 µg of recombinant hepatitis B vaccine. I. Seroconversion rate and adverse effects

    Directory of Open Access Journals (Sweden)

    Baldy José Luís da S

    2003-01-01

    Full Text Available A total of 250 dentists (53.6% men and 46.4% women, with a mean age of 35.1 ± 9.8 years, were submitted to serological tests for the diagnosis of hepatitis B (HB - HBsAg, anti-HBs, anti-HBc, HBeAg, and anti-HBe - using a radioimmunoassay. One or more of these markers were detected in 78 individuals (31.2% who were excluded from the group to be vaccinated. Of the 172 HB-susceptible individuals, 135 (78.5% responded to the call and were intradermally injected with three 2 µg doses of the Belgian HB recombinant vaccine, applied at an interval of one month between the 1st and 2nd dose and of five months between the 2nd and 3rd dose. A new determination of HB markers carried out 50 days after the 3rd dose showed that 110 (81.5% individuals had become anti-HBs positive (65.5% good responders and 34.5% poor responders. Mean serum anti-HBs titer of these 110 dentists was 42.4 U S/N, similar in both sexes. The adverse effects analyzed in 106 dentists were: (a local: pain (12.3%, burning sensation (14.1%, pruritus (25.5%, erythema (28.3%, local heat (18.9%, and a hypochromic spot (32.1%; (b systemic (4.7%: discomfort in two patients, and fever, anorexia, and asthenia in one patient each. Intradermal administration of a fourth 2 µg vaccine dose to 39 dentists (poor or non-responders increased the total number of anti-HBs-positive individuals from 110 (81.5% to 114 (84.4%, with the number of good responders increasing from 72 (65.5% to 85 (74.6%. We conclude that the Belgian recombinant vaccine applied in the scheme used here induces a high rate of seroconversion and causes only mild and transitory adverse effects.

  4. Low dose rate 137Cs Brachytherapy source calibration with farmer type ionisation chamber and specialised fabricated jig in Korle-Bu Teaching Hospital

    International Nuclear Information System (INIS)

    An important part of a general quality assurance (QA) program for brachytherapy dosimetry is the source calibration because wide ranges of uncertainties are quoted by manufactures. This research is aimed at calibrating LDR 137Cs brachytherapy source in the Korle-Bu Teaching Hospital by multiple-distance air kerma measurement technique using a specialized designed jig and a calibrated therapy ionization chamber. Specialized jig was fabricated with source holder positions and ionization chamber positions on the jig. Farmer type ionization chamber of volume 0.6cm3 was used with and without build up cap. The results were validated using well type ionization chamber on channels on 1 and 5 taking into account decay correction. Air Kerma rates were determined at multiple distances between 8cm to 12cm from measured charges recorded by Max 4000 electrometer. The scatter dose relationship described by Ezzell [1992] was used to determine scattered radiation. The analytical method of determining air kerma calibration factor of 137Cs described by Sharma et.al [2011] was used to determine beam quality correction factor for the 137Cs. Beam attenuation was determined. Experimental data were compared with manufacturer's quoted source strength for verification. Well type ionization chamber results and experimental results on channel V1 and V5 deviated by 2.39% and 1.58% respectively. Experimental data deviated by 4.73% and 1.24% from theoretical data on channels V1 and V5 respectively. The mean of the experimental data deviated from the theoretical data by ±3.1% and from the well type measurements data by ±1.98%. The well type chamber results compared well with the experimental data. This is an indication that the method used for source calibration is a reliable alternative method of source calibration. The method used in this work has proven to be an efficient way of determining the actual source strength of the LDR brachytherapy 137Cs source in Korle-Bu Radiotherapy Centre

  5. Enhancement of the Immunostimulatory Functions of Ex Vivo–Generated Dendritic Cells from Early-Stage Colon Cancer Patients by Consecutive Exposure to Low Doses of Sequential-Kinetic-Activated IL-4 and IL-12. A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Elisabetta Radice

    2015-08-01

    Full Text Available Dendritic cells (DCs, specialized antigen-presenting cells bridging innate and adaptive immunity, play a crucial role in determining specific immune response to tumors. Because of their potent immunoregulatory capacities, DCs have been exploited in anticancer vaccination, with limited success thus far. This pilot study compared low-dose interleukin (IL-4 and IL-12 prepared by sequential kinetic activation (SKA with standard doses of the same recombinant human cytokines on functional activity of ex vivo–generated monocyte-derived (Mo DCs from colon carcinoma patients and normal subjects. MoDCs were exposed to medium alone, SKA-IL-4 (0.5 fg/ml, or SKA-IL-12 (2 fg/ml, alone or consecutively combined, in parallel with rhIL-4 (50 ng/ml and rhIL-12 (1 ng/ml. Primary allogeneic one-way mixed lymphocyte reaction (MLR was the end point to assess in vitro T-lymphocyte proliferation in response to MoDCs, and secreted IL-12p70 and interferon-γ in MLR supernatants measured by ELISA to assay for T-helper 1–promoting MoDC phenotype. No single agent enhanced the compromised allostimulatory activity of MoDCs from colon cancer patients, unlike healthy donors. However, MoDCs from nonmetastatic colon cancer patients, after sequential exposure to SKA-IL-4 (48 hours and SKA-IL-12 (24 hours, displayed increased T-cell stimulatory capacity by MLR and acquired driving T-helper 1 polarization activity, although less markedly than the effects induced by recombinant human cytokines or found in normal subjects. These results point to an immunomodulatory capacity of low-dose SKA-IL-4 and SKA-IL-12 and encourage further investigation to provide clues for the rational development of new and more effective immunotherapeutic strategies against cancer.

  6. Breast cancer risk from low-dose exposures to ionizing radiation: results of parallel analysis of three exposed populations of women

    International Nuclear Information System (INIS)

    Breast cancer incidence data were analyzed from three populations of women exposed to ionizing radiation: survivors of the Hiroshima and Nagasaki atomic bombs, patients in Massachusetts tuberculosis sanitoria who were exposed to multiple chest fluoroscopies, and patients treated by X-rays for acute postpartum mastitis in Rochester, New York. Parallel analyses by radiation dose, age at exposure, and time after exposure suggested that risk of radiation-induced cancer increased approximately linearly with increasing dose and was heavily dependent on age at exposure; however, the risk was otherwise remarkably similar among the three populations, at least for ages 10 to 40 years at exposure, and followed the same temporal pattern of occurrence as did breast cancer incidence in nonexposed women of similar ages

  7. Biological Effects of Low-Dose Exposure

    CERN Document Server

    Komochkov, M M

    2000-01-01

    On the basis of the two-protection reaction model an analysis of stochastic radiobiological effects of low-dose exposure of different biological objects has been carried out. The stochastic effects are the results published in the last decade: epidemiological studies of human cancer mortality, the yield of thymocyte apoptosis of mice and different types of chromosomal aberrations. The results of the analysis show that as dependent upon the nature of biological object, spontanous effect, exposure conditions and radiation type one or another form dose - effect relationship is realized: downwards concave, near to linear and upwards concave with the effect of hormesis included. This result testifies to the incomplete conformity of studied effects of 1990 ICRP recomendations based on the linear no-threshold hypothesis about dose - effect relationship. Because of this the methodology of radiation risk estimation recomended by ICRP needs more precisian and such quantity as collective dose ought to be classified into...

  8. Myeloid Sarcoma of the Uterine Cervix as Presentation of Acute Myeloid Leukaemia after Treatment with Low-Dose Radioiodine for Thyroid Cancer: A Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Anne Sophie Weingertner

    2009-01-01

    Full Text Available The development of acute myeloid leukaemia after low-dose radioiodine therapy and its presentation as a myeloid sarcoma of the uterine cervix are both rare events. We report a case of acute myeloid leukaemia revealed by a myeloid sarcoma of the uterine cervix in a 48-year-old woman, 17 months after receiving a total dose of 100 mCi 131I for papillary thyroid cancer. A strict hematological follow-up of patients treated with any dose of 131I is recommended to accurately detect any hematological complications which might have been underestimated. Unusual presentations, such as chloroma of the uterine cervix, may reveal myeloid malignancy and should be kept in mind.

  9. A combination of high dose rate (10X FFF/2400 MU/min/10 MV X-rays) and total low dose (0.5 Gy) induces a higher rate of apoptosis in melanoma cells in vitro and superior preservation of normal melanocytes.

    Science.gov (United States)

    Sarojini, Sreeja; Pecora, Andrew; Milinovikj, Natasha; Barbiere, Joseph; Gupta, Saakshi; Hussain, Zeenathual M; Tuna, Mehmet; Jiang, Jennifer; Adrianzen, Laura; Jun, Jaewook; Catello, Laurice; Sanchez, Diana; Agarwal, Neha; Jeong, Stephanie; Jin, Youngjin; Remache, Yvonne; Goy, Andre; Ndlovu, Alois; Ingenito, Anthony; Suh, K Stephen

    2015-10-01

    The aim of this study was to determine the apoptotic effects, toxicity, and radiosensitization of total low dose irradiation delivered at a high dose rate in vitro to melanoma cells, normal human epidermal melanocytes (HEM), or normal human dermal fibroblasts (HDF) and to study the effect of mitochondrial inhibition in combination with radiation to enhance apoptosis in melanoma cells. Cells irradiated using 10X flattening filter-free (FFF) 10 MV X-rays at a dose rate of 400 or 2400 MU/min and a total dose of 0.25-8 Gy were analyzed by cell/colony counting, MitoTracker, MTT, and DNA-damage assays, as well as by quantitative real-time reverse transcriptase PCR in the presence or absence of mitochondrial respiration inhibitors. A dose rate of 2400 MU/min killed on average five-fold more melanoma cells than a dose rate 400 MU/min at a total dose of 0.5 Gy and preserved 80% survival of HEM and 90% survival of HDF. Increased apoptosis at the 2400 MU/min dose rate is mediated by greater DNA damage, reduced cell proliferation, upregulation of apoptotic genes, and downregulation of cell cycle genes. HEM and HDF were relatively unharmed at 2400 MU/min. Radiation induced upregulation of mitochondrial respiration in both normal and cancer cells, and blocking the respiration with inhibitors enhanced apoptosis only in melanoma cells. A high dose rate with a low total dose (2400 MU/min, 0.5 Gy/10X FFF 10 MV X-rays) enhances radiosensitivity of melanoma cells while reducing radiotoxicity toward HEM and HDF. Selective cytotoxicity of melanoma cells is increased by blocking mitochondrial respiration.

  10. Sustained platelet-sparing effect of weekly low dose paclitaxel allows effective, tolerable delivery of extended dose dense weekly carboplatin in platinum resistant/refractory epithelial ovarian cancer

    Directory of Open Access Journals (Sweden)

    Blagden Sarah

    2011-07-01

    Full Text Available Abstract Background Platinum agents have shown demonstrable activity in the treatment of patients with platinum resistant, recurrent ovarian cancer when delivered in a "dose-dense" fashion. However, the development of thrombocytopenia limits the weekly administration of carboplatin to no greater than AUC 2. Paclitaxel has a well-described platelet sparing effect however its use to explicitly provide thromboprotection in the context of dose dense carboplatin has not been explored. Methods We treated seven patients with platinum resistant ovarian cancer who had previously received paclitaxel or who had developed significant peripheral neuropathy precluding the use of further full dose weekly paclitaxel. Results We were able to deliver carboplatin AUC 3 and paclitaxel 20 mg/m2 with no thrombocytopenia or worsening of neuropathic side-effects, and with good activity. Conclusions We conclude that this regimen may be feasible and active, and could be formally developed as a "platinum-focussed dose-dense scaffold" into which targeted therapies that reverse platinum resistance can be incorporated, and merits further evaluation.

  11. Low dose computed tomography of the chest : Applications and limitations

    NARCIS (Netherlands)

    Gietema, H.A.

    2007-01-01

    In areas with a high intrinsic contrast such as the chest, radiation dose can be reduced for specific indications. Low dose chest CT is feasible and cannot only be applied for lung cancer screening, but also in daily routine and for early detection of lung destruction. We showed in a small sample of

  12. Low-dose cyclophosphamide-induced acute hepatotoxicity

    OpenAIRE

    Subramaniam, S. Ravih; Cader, Rizna Abdul; Mohd, Rozita; Yen, Kong Wei; Ghafor, Halim Abdul

    2013-01-01

    Patient: Male, 48 Final Diagnosis: Low dose cyclophosphamide-induced acute hepatotoxicity Symptoms: Epigastric pain Medication: Withdrawal of cyclophosphamide Clinical Procedure: — Specialty: Nephrology • Hepatology • Gastroenterology • Toxicology Objective: Unexpected drug reaction Background: Cyclophosphamide is commonly used to treat cancers, systemic vasculitides, and kidney diseases (e.g., lupus nephritis and focal segmental glomerulosclerosis). Acute adverse effects include bone marrow ...

  13. Fludarabine Phosphate, Low-Dose Total Body Irradiation, and Donor Stem Cell Transplant in Treating Patients With Hematologic Malignancies or Kidney Cancer

    Science.gov (United States)

    2015-10-13

    Accelerated Phase Chronic Myelogenous Leukemia; Adult Acute Lymphoblastic Leukemia in Remission; Adult Acute Myeloid Leukemia in Remission; Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); B-cell Chronic Lymphocytic Leukemia; Childhood Acute Lymphoblastic Leukemia in Remission; Childhood Acute Myeloid Leukemia in Remission; Childhood Chronic Myelogenous Leukemia; Childhood Myelodysplastic Syndromes; Childhood Renal Cell Carcinoma; Chronic Phase Chronic Myelogenous Leukemia; Clear Cell Renal Cell Carcinoma; de Novo Myelodysplastic Syndromes; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Nodal Marginal Zone B-cell Lymphoma; Previously Treated Myelodysplastic Syndromes; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Hodgkin Lymphoma; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Recurrent Cutaneous T-cell Non-Hodgkin Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Small Lymphocytic Lymphoma; Recurrent/Refractory Childhood Hodgkin Lymphoma; Refractory Chronic Lymphocytic Leukemia; Refractory Hairy Cell Leukemia; Refractory Multiple Myeloma; Relapsing Chronic Myelogenous Leukemia; Splenic Marginal Zone Lymphoma; Stage III Renal Cell Cancer; Stage IV Renal Cell Cancer; T-cell Large Granular Lymphocyte Leukemia; Type 1 Papillary Renal Cell Carcinoma; Type 2 Papillary Renal Cell Carcinoma; Waldenström Macroglobulinemia

  14. Human health effects of low doses of ionizing radiation: the BEIR III controversy

    International Nuclear Information System (INIS)

    Controversy in the BEIR III Subcommittee on Somatic Effects concerning human health effects of low doses of low-LET radiation has centered on (a) the appropriate dose-response relationship by which extrapolation to low doses of data obtained at relatively high doses should be governed, and (b) the appropriate human evidence which should be the basis of estimation of lifetime cancer risk from radiation exposure. It is shown that the use of the linear no-threshold dose-response relationship for extrapolation purposes is an excellent approximation that is in agreement with widely accepted fundamental radiobiological principles. The appropriate human data for derivation of cancer risks are the composite age-specific risks derived from all epidemiologic studies of human cancer resulting from partial-body and whole-body radiation exposure; this composite is in good agreement with the currently available cancer incidence dose-response data obtained from the Nagasaki Tumor Registry. The current version of BEIR III significantly underestimates the radiation-induced cancer risk because it ignores the effect of high-dose-rate, low-LET radiation on cell survival in relation to cancer induction probability, and because it emphasizes cancer mortality rather than cancer incidence. The controversy and the way in which it was resolved raises important questions about how the public and its representatives can in the future obtain objective scientific evaluations of issues that may have significant economic, social, and political implications

  15. A phase II randomized trial comparing standard and low dose rituximab combined with alemtuzumab as initial treatment of progressive chronic lymphocytic leukemia in older patients: a trial of the ECOG-ACRIN cancer research group (E1908).

    Science.gov (United States)

    Zent, Clive S; Victoria Wang, Xin; Ketterling, Rhett P; Hanson, Curtis A; Libby, Edward N; Barrientos, Jacqueline C; Call, Timothy G; Chang, Julie E; Liu, Jane J; Calvo, Alejandro R; Lazarus, Hillard M; Rowe, Jacob M; Luger, Selina M; Litzow, Mark R; Tallman, Martin S

    2016-03-01

    Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) patients requiring initial therapy are often older and frailer and unsuitable candidates for standard chemoimmunotherapy regimens. Shorter duration combination monoclonal antibody (mAb) therapy using alemtuzumab and rituximab has been shown to be effective and tolerable treatment for CLL. Standard dose anti-CD20 mAb therapy causes loss of CD20 expression by surviving CLL cells, which can be minimized by decreasing the mAb dose. We report a randomized phase II clinical trial enrolling older (≥ 65 years) patients (median age 76 years, n = 31) with treatment naïve progressive CLL. Patients received 8-12 weeks of standard subcutaneous alemtuzumab with either intravenous standard (375 mg/m(2) weekly)(n = 16) or low dose (20 mg/m(2) 3x week)(n = 15) rituximab. This study was closed before full accrual because the manufacturer withdrew alemtuzumab for treatment of CLL. The overall response rate was 90% with an 45% complete response rate, median progression-free survival of 17.9 months and no significant differences in outcome between the low and standard dose rituximab arms. The major toxicities were cytopenia and infection with one treatment fatality caused by progressive multifocal leukoencephalopathy but no other opportunistic infections. Combination mAb therapy was effective and tolerable treatment for older and frailer patients with progressive CLL, achieving a high rate of complete remissions. These data support the role of mAb in therapy for less fit CLL patients and the further study of low dose higher frequency anti-CD20 mAb therapy as a potentially more effective use of anti-CD20 mAb in the treatment of CLL.

  16. Fludarabine Phosphate, Low-Dose Total-Body Irradiation, and Donor Stem Cell Transplant Followed by Cyclosporine, Mycophenolate Mofetil, Donor Lymphocyte Infusion in Treating Patients With Hematopoietic Cancer

    Science.gov (United States)

    2016-08-01

    ; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides/Sezary Syndrome; Recurrent Renal Cell Cancer; Recurrent Small Lymphocytic Lymphoma; Recurrent/Refractory Childhood Hodgkin Lymphoma; Refractory Chronic Lymphocytic Leukemia; Refractory Hairy Cell Leukemia; Refractory Multiple Myeloma; Small Intestine Lymphoma; Splenic Marginal Zone Lymphoma; Stage II Multiple Myeloma; Stage III Multiple Myeloma; T-cell Large Granular Lymphocyte Leukemia; Testicular Lymphoma; Waldenström Macroglobulinemia

  17. Induction chemotherapy with carboplatin-paclitaxel followed by standard radiotherapy with concurrent daily low-dose cisplatin plus weekly paclitaxel for inoperable non-small-cell lung cancer.

    Science.gov (United States)

    Ardizzoni, Andrea; Scolaro, Tindaro; Mereu, Carlo; Cafferata, Mara Argenide; Tixi, Lucia; Bacigalupo, Almalina; Tiseo, Marcello; Monetti, Francesco; Rosso, Riccardo

    2005-02-01

    Both induction chemotherapy and concurrent platinating agents have been shown to improve results of thoracic irradiation in the treatment of locally advanced non-small-cell lung cancer (NSCLC). This phase II study investigated activity and feasibility of a novel chemoradiation regimen, including platinum and paclitaxel, both as induction chemotherapy and concurrently with thoracic radiotherapy. Previously untreated patients with histologically/cytologically proven unresectable stage I-III NSCLC were eligible. Induction chemotherapy consisted of 2 courses of 200 mg/m2 paclitaxel and carboplatin at AUC of 6 mg/mL/min every 3 weeks. From day 43, continuous thoracic irradiation (60 Gy in 30 fractions radiotherapy for 6 weeks) was given concurrently with daily cisplatin at a dose of 5 mg/m2 intravenously and weekly paclitaxel at a dose of 45 mg/m2 for 6 weeks. Fifteen patients were accrued in the first stage of the trial. According to the previous statistical considerations, accrual at the second stage of the study was halted as a result of the achievement an insufficient number of successes. Major toxicity of combined chemoradiation was grade III-IV esophagitis requiring hospitalization for artificial nutrition, which occurred in 58% of patients. Other toxicities included grade II-IV fatigue in 75% of patients and grade I-IV neuromuscular toxicity in 67%. Only 7 patients completed the treatment program as scheduled. Eight patients (53.3%; 95% confidence interval, 26.5-78.7%) had a major response (5 partial response, 3 complete response), 2 patients had disease progression, and 1 was stable at the end of treatment. Four patients died early. With a median follow up of 38 months, the median survival was 12 months. A combined chemoradiation program, including platinum and paclitaxel, appears difficult to deliver at full dose as a result of toxicity, mainly esophagitis. More active and less toxic combined modality treatments need to be developed for inoperable NSCLC.

  18. Low doses of arsenic, via perturbing p53, promotes tumorigenesis.

    Science.gov (United States)

    Ganapathy, Suthakar; Li, Ping; Fagman, Johan; Yu, Tianqi; Lafontant, Jean; Zhang, Guojun; Chen, Changyan

    2016-09-01

    In drinking water and in workplace or living environments, low doses of arsenic can exist and operate as a potent carcinogen. Due to insufficient understanding and information on the pervasiveness of environmental exposures to arsenic, there is an urgent need to elucidate the underlying molecular mechanisms of arsenic regarding its carcinogenic effect on human health. In this study, we demonstrate that low doses of arsenic exposure mitigate or mask p53 function and further perturb intracellular redox state, which triggers persistent endoplasmic reticulum (ER) stress and activates UPR (unfolded protein response), leading to transformation or tumorigenesis. Thus, the results suggest that low doses of arsenic exposure, through attenuating p53-regulated tumor suppressive function, change the state of intracellular redox and create a microenvironment for tumorigenesis. Our study also provides the information for designing more effective strategies to prevent or treat human cancers initiated by arsenic exposure. PMID:27425828

  19. Preparation and determination of kerma for Iridium 192 sources of low dose rate for brachytherapy; Preparacion y determinacion del kerma de fuentes de iridio-192 de baja tasa de dosis para braquiterapia

    Energy Technology Data Exchange (ETDEWEB)

    Tendilla, J.I.; Tovar M, V.; Mitsoura, E.; Aguilar H, F.; Alanis M, J. [Instituto Nacional de Investigaciones Nucleares, C.P. 52045-1, Salazar, Esrado de Mexico, D.F. (Mexico)

    2000-07-01

    The practice of Brachytherapy with Iridium-192 sources of low dose rate (0.4 - 0.8 Gy/h) is a technique used in the treatment of diverse illnesses. in this work the preparation, quality control and calibration are presented in terms of kerma in air of Iridium-192 using as target these recycled Iridium-Platinum wires. The targets were obtained as decayed sources of different radio therapeutical centers in the country and they were characterized by Scanning electron microscopy in order to determine their chemical composition. Subsequently it was developed an experimental design to establish the effect of neutron flux, geometrical array and irradiation time over the activity and percentage of the sources homogeneity. The homogeneity was determined by auto radiography and by Gamma spectroscopy. Once the optimal irradiation conditions were established, it is determined the apparent activity and kerma in air using a well type ionization chamber with traceability to a primary laboratory. Iridium-192 sources were obtained with an average homogeneity 96 %, apparent activity 282.129 {+-} 0.531 M Bq and kerma in air 0.03200 {+-} 0.00006 m Gy m/h A. (Author)

  20. Low Dose Risk, Decisions, and Risk Communication

    International Nuclear Information System (INIS)

    The overall research objective was to establish new levels of information about how people, groups, and communities respond to low dose radiation exposure. This is basic research into the social psychology of individual, group, and community responses to radiation exposures. The results of this research are directed to improving risk communication and public participation in management of environmental problems resulting from low dose radiation

  1. Lung Cancer Rates by Race and Ethnicity

    Science.gov (United States)

    ... HPV-Associated Ovarian Prostate Skin Uterine Cancer Home Lung Cancer Rates by Race and Ethnicity Language: English Español ( ... Tweet Share Compartir The rate of people getting lung cancer or dying from lung cancer varies by race ...

  2. Effect of low-dose ionizing radiation on immune system in mice

    Energy Technology Data Exchange (ETDEWEB)

    Hoshi, Y.; Sakai, K. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

    2002-07-01

    Low-dose irradiation induces a number of biological functions in mice. Nomura et al. have demonstrated that the low-dose irradiation elevates the level of antioxidants and gives suppressive effects on some chemically induced reactive oxygen species (ROS)-related disease models. We paid attention to this stimulated immunological function by low dose irradiation and started the study that by low dose irradiation and started the study that by low-dose rate irradiation. The enhancement of immune response in mice under various conditions will be discussed.

  3. Low doses of ethanolic extract of Boldo (Peumus boldus) can ameliorate toxicity generated by cisplatin in normal liver cells of mice in vivo and in WRL-68 cells in vitro, but not in cancer cells in vivo or in vitro

    Institute of Scientific and Technical Information of China (English)

    Jesmin Mondal; Kausik Bishayee; Ashis Kumar Panigrahi; Anisur Rahman Khuda-Bukhsh

    2014-01-01

    OBJECTIVE:Use of cisplatin, a conventional anticancer drug, is restricted because it generates strong hepatotoxicity by accumulating in liver. Therefore its anticancer potential can only be fully exploited if its own toxicity is considerably reduced. Towards this goal, ethanolic extract of the plant, Boldo (Peumus boldus), known for its antihepatotoxic effects, was used simultaneously with cisplatin, to test its ability to reduce cisplatin’s cytotoxicity without affecting its anticancer potential. METHODS: The cytotoxicity of Boldo extract (BE) and cisplatin, administered alone and in combination, was determined in three cancer cell lines (A549, HeLa, and HepG2) and in normal liver cells (WRL-68). Drug-DNA interaction, DNA damage, cell cycle, apoptosis, reactive oxygen species (ROS) and mitochondrial membrane potential (MMP, ΔΨ) were also studied. Hepatotoxicity and antioxidant activity levels were determined by alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase and glutathione assays in mice. The cytotoxicity of related proteins was tested by Western blotting. RESULTS:Co-administration of BE and cisplatin increased viability of normal cells, but had no effect on the viability of cancer cells. Boldo protected liver from damage and normalized different antioxidant enzyme levels in vivo and also reduced ROS and re-polarized MMP in vitro. Bax and cytochrome c translocation was reduced with caspase 3 down-regulation. Further, a drug-DNA interaction study revealed that BE reduced cisplatin’s DNA-binding capacity, resulting in a reduction in DNA damage. CONCLUSION: Results indicated that a low dose of BE could be used beneifcial y in combination with cisplatin to reduce its toxicity without hampering cisplatin’s anticancer effect. These ifndings signify a potential future use of BE in cancer therapy.

  4. The effect of low-dose β-blocker on heart rate and heart rate variability in health subjects wth a resting heart rate of less than 65 beats per minute: Effect on the quality of prospective electrocardiography-gated coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chul Hwan; Kim, Tae Hoon [Dept. of Radiology and Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of); Lee, Sang Min [Dept. of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Hong, Yoo Jin [Dept. of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2015-02-15

    We assessed the effect of a low-dose β-blocker on heart rate (HR), HR variability (HRV) and image quality of prospective electrocardiography-gated coronary CT angiography (CCTA) in healthy subjects with low HR. CCTA was performed with a 64-slice CT in 75 subjects with a HR of less than 65 beats per minute (bpm). Subjects were divided into 2 groups: Group 1 (G1), 35 with a low dose β-blocker; and Group 2 (G2), 40 without pre-medication. The image quality (IQ) of the CCTA was assessed on a 4-point grading scale (1, poor; 4, excellent). Initial HR (bpm) was not different between the 2 groups. HR during CCTA was lower in G1 than G2 (50.3 ± 5.6 vs. 53.3 ± 4.8, p = 0.016). HRV was not different between the 2 groups. Per-segment analysis showed better IQ at the mid-segment of the right coronary artery (3.0 ± 0.9 vs. 2.5 ± 1.1, p = 0.039) and the first diagonal branch (3.4 ± 0.6 vs. 3.1 ± 0.7, p = 0.024), in the G1 than the G2 group, respectively. The IQ was negatively correlated with HR, but no correlation was found between HRV and IQ. The IQs in the per-vessel analysis were not different between the 2 groups. Low-dose β-blocker reduced HR and improved the IQ of CCTA in a few segments, even at a HR of less than 65 bpm. However the effect was limited.

  5. Low-Dose-Rate Computed Tomography System Utilizing 25 mm/s-Scan Silicon X-ray Diode and Its Application to Iodine K-Edge Imaging Using Filtered Bremsstrahlung Photons

    Science.gov (United States)

    Matsushita, Ryo; Sato, Eiichi; Yanbe, Yutaka; Chiba, Hiraku; Maeda, Tomoko; Hagiwara, Osahiko; Matsukiyo, Hiroshi; Osawa, Akihiro; Enomoto, Toshiyuki; Watanabe, Manabu; Kusachi, Shinya; Sato, Shigehiro; Ogawa, Akira; Onagawa, Jun

    2013-03-01

    A low-dose-rate X-ray computed tomography (CT) system is useful for reducing absorbed dose for patients. The CT system with a tube current of sub-mA was developed using a silicon X-ray diode (Si-XD). The Si-XD is a high-sensitivity Si photodiode (PD) selected for detecting X-ray photons, and the X-ray sensitivity of the Si-XD was twice as high as that of Si-PD cerium-doped yttrium aluminum perovskite [YAP(Ce)]. X-ray photons are directly detected using the Si-XD without a scintillator, and the photocurrent from the diode is amplified using current-voltage and voltage-voltage amplifiers. The output voltage is converted into logical pulses using a voltage-frequency converter with a maximum frequency of 500 kHz, and the frequency is proportional to the voltage. The pulses from the converter are sent to the differentiator with a time constant of 500 ns to generate short positive pulses for counting, and the pulses are counted using a counter card. Tomography is accomplished by repeated linear scans and rotations of an object, and projection curves of the object are obtained by the linear scan. The exposure time for obtaining a tomogram was 5 min at a scan step of 0.5 mm and a rotation step of 3.0°. The tube current and voltage were 0.55 mA and 60 kV, respectively, and iodine K-edge CT was carried out using filtered bremsstrahlung X-ray spectra with a peak energy of 38 keV.

  6. Association between absolute volumes of lung spared from low-dose irradiation and radiation-induced lung injury after intensity-modulated radiotherapy in lung cancer: a retrospective analysis.

    Science.gov (United States)

    Chen, Jinmei; Hong, Jinsheng; Zou, Xi; Lv, Wenlong; Guo, Feibao; Hong, Hualan; Zhang, Weijian

    2015-11-01

    The aim of this study was to investigate the association between absolute volumes of lung spared from low-dose irradiation and radiation-induced lung injury (RILI) after intensity-modulated radiotherapy (IMRT) for lung cancer. The normal lung relative volumes receiving greater than 5, 10, 20 and 30 Gy (V5-30) mean lung dose (MLD), and absolute volumes spared from greater than 5, 10, 20 and 30 Gy (AVS5-30) for the bilateral and ipsilateral lungs of 83 patients were recorded. Any association of clinical factors and dose-volume parameters with Grade ≥2 RILI was analyzed. The median follow-up was 12.3 months; 18 (21.7%) cases of Grade 2 RILI, seven (8.4%) of Grade 3 and two (2.4%) of Grade 4 were observed. Univariate analysis revealed the located lobe of the primary tumor. V5, V10, V20, MLD of the ipsilateral lung, V5, V10, V20, V30 and MLD of the bilateral lung, and AVS5 and AVS10 of the ipsilateral lung were associated with Grade ≥2 RILI (P lung was prognostic for Grade ≥2 RILI (P = 0.010, OR = 0.272, 95% CI: 0.102-0.729). Receiver operating characteristic curves indicated Grade ≥2 RILI could be predicted using AVS5 of the ipsilateral lung (area under curve, 0.668; cutoff value, 564.9 cm(3); sensitivity, 60.7%; specificity, 70.4%). The incidence of Grade ≥2 RILI was significantly lower with AVS5 of the ipsilateral lung ≥564.9 cm(3) than with AVS5 lung were associated with Grade ≥2 RILI, and AVS5 of the ipsilateral lung was prognostic for Grade ≥2 RILI for lung cancer after IMRT. PMID:26454068

  7. Study of the radiation levels in low dose rate brachytherapy zones of the National Institute of Neoplastic Illnesses; Estudio de los Niveles de Radiacion en Zonas de Braquiterapia de Baja Tasa de Dosis del Instituto Nacional de Enfermedades Neoplasicas

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa J, N.; Mora Y, B. [Instituto Nacional de Enfermedades Neoplasicas, Lima (Peru)]. e-mail: navorf01@yahoo.es

    2006-07-01

    The present study has as objective to evaluate the radiation levels of the Brachytherapy work areas of low dose rate (Gammateque, nurses station and of hospitalization rooms of patients RIC of 4th, 5th Floor-East) and to estimate the effective dose of the occupationally exposed personnel and the public in general. The measurements of the dose rate in these areas, were registered with a radiations monitor Inspector trademark, during a period of 60 days, without altering the routinary work conditions. The more high levels of environmental dose equivalent rate registered in the different work areas its are of 1.41 and 47.78 {mu}Sv/h rooms 1 and 2 in the Gammateque environments, in the hospitalization rooms of the 4th and 5th floor in the point 1 are of 40.77 and 23.67, {mu}Sv/h respectively and in the point 2 are of 129.19 and 39.93, {mu}Sv/h respectively, and in the nurses station of the 4th and 5th floor its are respectively of 7.62 u Sv/h and 0.45 u Sv/h. According to the carried out measurements and the permanency in the work place is possible to estimate the effective dose involved to the occupationally exposed personnel. The personnel that works in Gammateque could be receiving respectively as maximum dose 0.61 mSv/month, and the personnel that works in the nurses station of 13.17 and 0.78 mSv/year in the 4th and 5th floor. These registered differences among the two floors are due to that the 5th floor counts with the shielding systems (screen) contrary to the 4th, another of the factors is the distribution form of the patient beds RIC. We should have present that the radiation levels although in some cases it is very high, however, they are below of the permissible limits according to standards, but it is still possible to reduce even more, the radiation levels in the critical points fulfilling with the ALARA principle. (Author)

  8. Characteristics of repair following very low doses

    International Nuclear Information System (INIS)

    The effects of ionizing radiation on living systems being with the physical processes of energy deposition and develop through many stages of chemical reaction and biological response. The modeling effort attempts to organize the available data and theories of all of these stages into self-consistent models that can be compared and tested. In some cases, important differences among models result in only small differences in cell survival within the ranges of dose and dose rate that are normally investigated. To overcome this limitation, new ways of irradiating cells at extremes of dose rate, or ways of evaluating the effects of very small doses, are developed. Mathematical modeling and cellular studies complement each other. It has recently been found that some mechanisms are not adequate to account for the interaction of dose and repair time as they affect the reproductive survival of plateau-phase Chinese hamster ovary (CHO) cells. Repair of radiation-induced cellular damage plays a central role in the survival of cells exposed to doses of 1 Gy or more. This repair is responsible for the dose rate, split-dose and delayed plating effect and can be evaluated. Because split-dose and dose-rate experiments involve repair during irradiation and delayed plating experiments involve repair after irradiation is completed, it was originally thought that different repair processes were involved. It is now clear that this is not necessarily the case. Appropriately designed models can account for observed effects at conventional doses (1 Gy or more) whether they assume all damage is lethal unless repaired or some damage is innocuous unless it interacts with additional damage. The fact that the survival following a plating delay is always less than the survival following immediate plating at low doses indicates that the damage produced is probably not potentially lethal

  9. Clinical value of a one-stop-shop low-dose lung screening combined with {sup 18}F-FDG PET/CT for the detection of metastatic lung nodules from colorectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Han, Yeon Hee; Lim, Seok Tae; Jeong, Hwan Jeong; Sohn, Myung Hee [Dept. of Nuclear Medicine, Research Institute of Clinical Medicine, Chonbuk National University-Biomedical Research Institute, Chonbuk National University Hospital, Cyclotron Research Center, Molecular Imaging and Therapeutic Medicine Research Center, Chonbuk National University Medical School and Hospital, Jeonju (Korea, Republic of)

    2016-06-15

    The aim of this study was to evaluate the clinical usefulness of additional low-dose high-resolution lung computed tomography (LD-HRCT) combined with 18F-fluoro-2-deoxyglucose positron emission tomography with CT (18F-FDG PET/CT) compared with conventional lung setting image of 18F-FDG PET/CT for the detection of metastatic lung nodules from colorectal cancer. From January 2011 to September 2011, 649 patients with colorectal cancer underwent additional LD-HRCT at maximum inspiration combined with 18F-FDG PET/CT. Forty-five patients were finally diagnosed to have lung metastasis based on histopathologic study or clinical follow-up. Twenty-five of the 45 patients had ≤5 metastatic lung nodules and the other 20 patients had  >5 metastatic nodules. One hundred and twenty nodules in the 25 patients with ≤5 nodules were evaluated by conventional lung setting image of 18F-FDG PET/CT and by additional LD-HRCT respectively. Sensitivities, specificities, diagnostic accuracies, positive predictive values (PPVs), and negative predictive values (NPVs) of conventional lung setting image of 18F-FDG PET/CT and additional LD-HRCT were calculated using standard formulae. The McNemar test and receiver-operating characteristic (ROC) analysis were performed. Of the 120 nodules in the 25 patients with ≤5 metastatic lung nodules, 66 nodules were diagnosed as metastatic. Eleven of the 66 nodules were confirmed histopathologically and the others were diagnosed by clinical follow-up. Conventional lung setting image of 18F-FDG PET/CT detected 40 of the 66 nodules and additional LD-HRCT detected 55 nodules. All 15 nodules missed by conventional lung setting imaging but detected by additional LD-HRCT were <1 cm in size. The sensitivity, specificity, and diagnostic accuracy of the modalities were 60.6 %, 85.2 %, and 71.1 % for conventional lung setting image and 83.3 %, 88.9 %, and 85.8 % for additional LD-HRCT. By ROC analysis, the area under the ROC curve (AUC) of conventional

  10. LOW DOSE MAGNESIUM SULPHATE REGIME FOR ECLAMPSIA

    Directory of Open Access Journals (Sweden)

    Bangal V

    2009-09-01

    Full Text Available Pre- eclampsia is one of the commonest medical complications seen during pregnancy. It contributes significantly to maternal and perinatal morbidity and mortality. Dr.J.A.Pritchard in 1955, introduced magnesium sulphate for control of convulsions in eclampsia and is used worldwide. Considering the low body mass index of indian women, a low dose magnesium sulphate regime has been introduced by some authors. Present study was carried out at tertiary care centre in rural area. Fifty cases of eclampsia were randomly selected to find out the efficacy of low dose magnesium sulphate regime to control eclamptic convulsions. Maternal and perinatal outcome and magnesium toxicity were analyzed. It was observed that 86% cases responded to initial intravenous dose of 4 grams of 20% magnesium sulphate . Eight percent cases, who got recurrence of convulsion, were controlled by additional 2 grams of 20% magnesium sulphate. Six percent cases required shifting to standard Pritchard regime, as they did not respond to low dose magnesium sulphate regime. The average total dose of magnesium sulphate required for control of convulsions was 20 grams ie. 54.4% less than that of standard Pritchard regime. The maternal and perinatal morbidity and mortality in the present study werecomparable to those of standard Pritchard regime. The study did not find a single case of magnesium related toxicity with low dose magnesium sulphate regime. Low dose magnesium sulphate regime was found to be safe and effective in eclampsia.

  11. Low dose rapamycin exacerbates autoimmune experimental uveitis.

    Directory of Open Access Journals (Sweden)

    Zili Zhang

    Full Text Available BACKGROUND: Rapamycin, a potent immune modulator, is used to treat transplant rejection and some autoimmune diseases. Uveitis is a potentially severe inflammatory eye disease, and 2 clinical trials of treating uveitis with rapamycin are under way. Unexpectedly, recent research has demonstrated that low dose rapamycin enhances the memory T cell population and function. However, it is unclear how low dose rapamycin influences the immune response in the setting of uveitis. DESIGN AND METHODS: B10.RIII mice were immunized to induce experimental autoimmune uveitis (EAU. Ocular inflammation of control and rapamycin-treated mice was compared based on histological change. ELISPOT and T cell proliferation assays were performed to assess splenocyte response to ocular antigen. In addition, we examined the effect of rapamycin on activation-induced cell death (AICD using the MitoCapture assay and Annexin V staining. RESULTS: Administration of low dose rapamycin exacerbated EAU, whereas treating mice with high dose rapamycin attenuated ocular inflammation. The progression of EAU by low dose rapamycin coincided with the increased frequency of antigen-reactive lymphocytes. Lastly, fewer rapamycin-treated T cells underwent AICD, which might contribute to exaggerated ocular inflammation and the uveitogenic immune response. CONCLUSION: These data reveal a paradoxical role for rapamycin in uveitis in a dose-dependent manner. This study has a potentially important clinical implication as rapamycin might cause unwanted consequences dependent on dosing and pharmacokinetics. Thus, more research is needed to further define the mechanism by which low dose rapamycin augments the immune response.

  12. LOW DOSE RISK, DECISIONS, and RISK COMMUNICATION

    International Nuclear Information System (INIS)

    The objective of this project is to conduct basic research on how people receive, evaluate, and form positions on scientific information and its relationship to low-dose radiation exposure. There are three major areas of study in our research program. First is the development of theories, frameworks and concepts essential to guiding data collection and analysis. The second area is a program of experimental studies on risk perception, evaluation of science information, and the structure of individual positions regarding low-dose exposures. Third is the community-level studies to examine and record how the social conditions, under which science communications take place, influence the development of attitudes and opinions about: low-dose exposures, the available management options, control of radiation risks, and preferences for program and policy goals

  13. Mechanisms of Low Dose Radio-Suppression of Genomic Instability

    Energy Technology Data Exchange (ETDEWEB)

    Engelward, Bevin P

    2009-09-16

    The major goal of this project is to contribute toward the elucidation of the impact of long term low dose radiation on genomic stability. We have created and characterized novel technologies for delivering long term low dose radiation to animals, and we have studied genomic stability by applying cutting edge molecular analysis technologies. Remarkably, we have found that a dose rate that is 300X higher than background radiation does not lead to any detectable genomic damage, nor is there any significant change in gene expression for genes pertinent to the DNA damage response. These results point to the critical importance of dose rate, rather than just total dose, when evaluating public health risks and when creating regulatory guidelines. In addition to these studies, we have also further developed a mouse model for quantifying cells that have undergone a large scale DNA sequence rearrangement via homologous recombination, and we have applied these mice in studies of both low dose radiation and space radiation. In addition to more traditional approaches for assessing genomic stability, we have also explored radiation and possible beneficial effects (adaptive response), long term effects (persistent effects) and effects on communication among cells (bystander effects), both in vitro and in vivo. In terms of the adaptive response, we have not observed any significant induction of an adaptive response following long term low dose radiation in vivo, delivered at 300X background. In terms of persistent and bystander effects, we have revealed evidence of a bystander effect in vivo and with researchers at and demonstrated for the first time the molecular mechanism by which cells “remember” radiation exposure. Understanding the underlying molecular mechanisms by which radiation can induce genomic instability is fundamental to our ability to assess the biological impact of low dose radiation. Finally, in a parallel set of studies we have explored the effects of heavy

  14. Dual effect of low dose of irradiation on wheat x Leymus angustus: enhancement and damage

    International Nuclear Information System (INIS)

    The effects of low dose of γ-irradiation on wheat x Leymus angustus were studied. The results showed that appropriate low dose of irradiation can overcome the cross incompatibility and enhance seed setting, on the other hand, restrain the development of hybrid embryos and make rate of seed containing embryos decrease. When irradiation is used to enhance wide hybridization, the damage of low dose of γ-irradiation should be considered

  15. Tardive dyskinesia with low dose amisulpride.

    Science.gov (United States)

    Tharoor, Hema; Padmavati, R

    2013-01-01

    In recent years, there has been an increasing trend to use amisulpride in the treatment of dysthymia and also as an adjunct treatment in patients with major depression. At low doses (50 mg), amisulpride preferentially blocks presynaptic auto receptors, enhances dopamine release, and therefore acts as a dopaminergic compound able to resolve the dopaminergic hypo activity that characterizes depression. Based on experimental data, amisulpride is the drug of choice for dopaminergic transmission disorders, both in depression and in schizophrenia. This case highlights the development of dyskinesia in a depressed patient treated with low dose amisulpride and fluvoxamine.

  16. Low-Dose Radioactive Iodine Destroys Thyroid Tissue Left after Surgery

    Science.gov (United States)

    A low dose of radioactive iodine given after surgery for thyroid cancer destroyed (ablated) residual thyroid tissue as effectively as a higher dose, with fewer side effects and less exposure to radiation, according to two randomized controlled trials.

  17. Stimulation of seeds by low dose irradiation

    International Nuclear Information System (INIS)

    The first section of the bibliography lists materials on the stimulation of seeds by low dose irradiation, with particular reference to stimulation of germination and yield. The second section contains a small number of selected references on seed irradiation facilities. (author)

  18. Evaluation of a combination of low-dose ketamine and low-dose midazolam in terminal dyspnea-attenuation of "double-effect"

    Directory of Open Access Journals (Sweden)

    Abhijit Kanti Dam

    2008-01-01

    Full Text Available Aim: Of all symptoms in palliative medicine those concerning respiration are most excruciating and difficult to treat. Reticence about the use of morphine for palliation of dyspnea is common, especially in nonmalignant diseases, as there is a fear of causing respiratory depression, particularly where Chronic Obstructive Pulmonary Disease (COPD exists. This factor is also compounded by the lack of availability of morphine in parts of developing countries. Ketamine has excellent anesthetic and analgesic effects in addition to being easily available. It produces bronchodilatation and does not produce respiratory or cardiovascular depression. The author seeks to evaluate the role of low-dose (0.2 mg/kg ketamine and midazolam (0.02 mg/kg in the attenuation of terminal dyspnea. Methods: Sixteen patients with terminal dyspnea, admitted to the Critical Care Unit (CCU with cancer and other noncancer diagnoses were recruited. The subjective component of dyspnea was assessed using the Graphic Rating Scale (GRS, which has values from 0 - 10, 10 being maximum dyspnea. Each patient received a low-dose of ketamine and midazolam for relief of dyspnea. All the patients received low-flow (2 L/min. oxygen therapy via nasal cannula. Immediately after admission, all the patients were reassured and nursed in a decubitus position of their choice. The GRS was recorded at the point of admission, 10 minutes after starting oxygen therapy, and ten minutes after administration of low-dose ketamine and midazolam. Hemodynamic parameters were also recorded at these three points. Result: All the patients who enrolled in our study had significant dyspnea at admission, as was evident from the GRS scores of 8.250 (SD 0.91, respiratory rate of 28.56 (SD 5.0, mean arterial blood pressure (MABP of 102.7 (SD 14.63, pulse rate of 115.62 (SD 23.3, and SpO2 of 92.43 (SD 2.38. All the patients benefited from the combination of ketamine and midazolam, as evidenced by the statistically

  19. Skin Cancer Rates by Race and Ethnicity

    Science.gov (United States)

    ... Search The CDC Cancel Submit Search The CDC Skin Cancer Note: Javascript is disabled or is not supported ... HPV-Associated Lung Ovarian Prostate Uterine Cancer Home Skin Cancer Rates by Race and Ethnicity Language: English Español ( ...

  20. Activated T-cell Therapy, Low-Dose Aldesleukin, and Sargramostim in Treating Patients With Ovarian, Fallopian Tube, or Primary Peritoneal Cancer That is Stage III-IV, Refractory, or Recurrent

    Science.gov (United States)

    2016-02-15

    Malignant Ovarian Clear Cell Tumor; Malignant Ovarian Serous Tumor; Recurrent Fallopian Tube Carcinoma; Recurrent Ovarian Carcinoma; Recurrent Primary Peritoneal Carcinoma; Stage IIIA Fallopian Tube Cancer; Stage IIIA Ovarian Cancer; Stage IIIA Primary Peritoneal Cancer; Stage IIIB Fallopian Tube Cancer; Stage IIIB Ovarian Cancer; Stage IIIB Primary Peritoneal Cancer; Stage IIIC Fallopian Tube Cancer; Stage IIIC Ovarian Cancer; Stage IIIC Primary Peritoneal Cancer; Stage IV Fallopian Tube Cancer; Stage IV Ovarian Cancer; Stage IV Primary Peritoneal Cancer

  1. DoReMi workshop on multidisciplinary approaches to evaluating cancer risks associated with low-dose internal contamination; Approches multidisciplinaires pour l'evaluation du risque de cancer associe aux contaminations internes aux faibles doses: synthese du seminaire scientifique organise dans le cadre du projet europeen DoReMi

    Energy Technology Data Exchange (ETDEWEB)

    Laurier, D.; Guseva Canu, I.; Bertho, J.M.; Blanchardon, E.; Rage, E. [Institut de radioprotection et de surete nucleaire, IRSN, Fontenay-aux-Roses Cedex (France); Baatout, S. [Belgian Nuclear Research Centre, SCK-CEN, Mol (Belgium); Bouffler, S. [Health Protection Agency, Centre for Radiation Chemical and Environmental Hazards, HPA-CRCE, Chilton (United Kingdom); Cardis, E. [Centre for Research in Environmental Epidemiology, CREAL, Barcelona (Spain); Gomolka, M.; Kreuzer, M. [Federal Office for Radiation Protection, Department of Radiation Protection and Health, BfS, Neuherberg (Germany); Hall, J. [Inserm U612, Institut Curie, Orsay (France); Kesminiene, A. [International Agency for Research on Cancer, Section of Environment and Radiation, IARC, Lyon (France)

    2012-01-15

    A workshop dedicated to cancer risks associated with low-dose internal contamination was organised in March 2011, in Paris, in the framework of the DoReMi (Low Dose Research towards Multidisciplinary Integration) European Network of Excellence. The aim was to identify the best epidemiological studies that provide an opportunity to develop a multidisciplinary approach to improve the evaluation of the cancer risk associated with internal contamination. This workshop provided an opportunity for in-depth discussions between researchers working in different fields including (but not limited to) epidemiology, dosimetry, biology and toxicology. Discussions confirmed the importance of research on the health effects of internal contamination. Several existing epidemiological studies provide a real possibility to improve the quantification of cancer risk associated with internal emitters. Areas for future multidisciplinary collaborations were identified, that should allow feasibility studies to be carried out in the near future. The goal of this paper is to present an overview of the presentations and discussions that took place during this workshop. (authors)

  2. Effects of low doses; Effet des faibles doses

    Energy Technology Data Exchange (ETDEWEB)

    Le Guen, B. [Electricite de France (EDF-LAM-SCAST), 93 - Saint-Denis (France)

    2001-07-01

    Actually, even though it is comfortable for the risk management, the hypothesis of the dose-effect relationship linearity is not confirmed for any model. In particular, in the area of low dose rate delivered by low let emitters. this hypothesis is debated at the light of recent observations, notably these ones relative to the mechanisms leading to genetic instability and induction eventuality of DNA repair. The problem of strong let emitters is still to solve. (N.C.)

  3. Low doses of glyphosate change the response of soybean to later glyphosate exposures

    Science.gov (United States)

    The stimulatory effect of low doses of toxic substances is known as hormesis. Many herbicides that cause severe injury to plants at recommended rates, promote growth or have other stimulatory effects at very low doses. The objective of this study was to evaluate glyphosate-induced hormesis in soyb...

  4. Effect of low dose of gamma radiation on the induction and signalling of complex damages of DNA in the mammals cells

    International Nuclear Information System (INIS)

    The work presented in the frame of this thesis are in line with the studies on the radioinduced damages of DNA in order to better understand their genotoxic effects and the associated risks. The different radioinduced damages of DNA are given, the complex damages, double strand-break and multiple damages are particularly detailed as well as their methods of detection. Are presented the systems implemented in the cell in order to point the radioinduced damages and to implement the repair systems of these lesions. Then, are presented the knowledge on the effects of low doses and low dose rates. The whole of this work has for objective to highlight the mechanisms by which the reduction of dose rate allows an increase of cell survival. By a better knowledge of the system implemented in response to a low dose rate irradiation, it is possible to valid or not the linear without threshold model of low doses effects and consequently to better understand the eventual risks of cancer linked to exposures of low doses of ionizing radiation. (N.C.)

  5. HiLo: Multicentre randomized phase III clinical trial of high vs low dose radioiodine, with or without recombinant human thyroid stimulating hormone (rhTSH), for remnant ablation for differentiated thyroid cancer

    Energy Technology Data Exchange (ETDEWEB)

    Mallick, U. [Freeman Hospital, Newcastle, Newcastle upon Tyne (United Kingdom); Harmer, C.; Clarke, S.; Moss, L.; Nicol, A.; Clarke, P.; Smellie, J.; McCready, R.; Farnell, K.; Franklyn, J.; John, R.; Nutting, C.; Yap, B.; Lemon, C.; Wadlsey, J.; Gerrard, G.; Roques, T.; Macias, E.; Whitaker, S.; Abdul-Hamid, A.; Alvarez, P.; Kadalayil, L.; Hackshaw, A.

    2012-07-01

    Recommended treatment for most patients with differentiated thyroid cancer is surgery followed by radioiodine ablation. Current practice in many centres is to use a high administered activity of 3.7 GBq (100 mCi). However, a lower activity (1.1 GBq or 30 mCi) has advantages including a shorter stay in hospital isolation and lower risk of side effects, including the risk of a second cancer. Also, Thyrogen (rhTSH) allows patients to continue thyroid hormone replacement during ablation, avoiding symptoms of hypothyroidism and also reduces total body radiation dose. We conducted a large randomized factorial multi centre trial to simultaneously address whether ablation success rates are similar using (i) either 1.1 GBq or 3.7 GBq, and (ii) either Thyrogen or thyroid hormone withdrawal. It is the first ever national prospective trial in thyroid cancer in the UK. Final results will be available in 2011

  6. Epigenomic Adaptation to Low Dose Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gould, Michael N. [Univ. of Wisconsin, Madison, WI (United States)

    2015-06-30

    The overall hypothesis of this grant application is that the adaptive responses elicited by low dose ionizing radiation (LDIR) result in part from heritable DNA methylation changes in the epigenome. In the final budget period at the University of Wisconsin-Madison, we will specifically address this hypothesis by determining if the epigenetically labile, differentially methylated regions (DMRs) that regulate parental-specific expression of imprinted genes are deregulated in agouti mice by low dose radiation exposure during gestation. This information is particularly important to ascertain given the 1) increased human exposure to medical sources of radiation; 2) increased number of people predicted to live and work in space; and 3) enhanced citizen concern about radiation exposure from nuclear power plant accidents and terrorist ‘dirty bombs.’

  7. A consideration of low dose radiation effects on human health

    International Nuclear Information System (INIS)

    On March 11, 2011, an earthquake categorized as 9 Mw occurred off the northeast coast of Japan. The subsequent destructive tsunami disabled emergency units of Fukushima Dai'ichi Nuclear Power Plant and caused partial meltdown of reactors and explosions. Resulting radiation releases forced large evacuations, bore concerns about food and water and fears against human health. In this manuscript, we described the effect of radiation, especially low dose radiation below 100 mSv, on cancer risk, focusing on fetuses and children. (author)

  8. 低剂量CT与4肿瘤标记物联合检测对肺癌高危人群筛查的研究%Low-dose spiral CT combined tumor markers for lung cancer screening high-risk groups

    Institute of Scientific and Technical Information of China (English)

    李丰章; 邹南安; 胡含明; 巫启恒; 欧阳良

    2015-01-01

    目的:评价低剂量螺旋CT(low dose spiral computed tomography,LDCT)扫描联合4种肺癌肿瘤标记物(人多效蛋白PTN、神经元特异烯醇化酶NSE、细胞角质蛋白Cyfra21-1及癌胚抗原CEA)检测对肺癌高危人群早期肺癌筛查的阳性率及特异性。方法分析及统计2011年-2013年进行LDCT扫描及肿瘤标志物联合筛查肺癌高危人群体的检查结果,并与常规早期肺癌筛查研究结果进行比较分析。结果 LDCT与常规剂量CT扫描肺部阳性检出率及病变影像学表现基本一致,无统计学差异(P>0.05),而辐射剂量明显下降,是常规剂量的6.38%(P0.05),and radiation dose decreased obviously,it was regular doses of 6.38%(P<0.05);Four types of lung cancer tumor markers combined de-tection sensitivity about 95%,specificity about 80% of lung cancer,was of great significance for early diagnosis of lung cancer,4 kinds of this experimental lung cancer tumor markers positive rate was 1.58%(6 cases),ultimately determine the early lung cancer was 1.05%(4 cases),LDCT to detect lesions positive rate was 12.1%in this group (46 cases),of which 8 cases of imaging diagnosis of early lung cancer (2.11%),and finally only 4 cases (1.05%) diagnosed with lung cancer early,imaging in the diagnosis of false positives. To participate in this study,a total of 759 people,of whom LDCT and tumor markers combined test group(379,female:379 people,average age 54.3 years,7 patients with copd;male:203,the average age of 57.6 years,26 patients with copd screening lung were 12.1%(46 people with lung CT positive performance,6 people joint inspection tumor markers were positive,4 cases were diagnosed with lung cancer). Conclusion LDCT two inspection methods and lung cancer tumor markers have complementary ad-vantages,early lung cancer detection rate was 1.05%,avoid single check false positive events,joint detection more conducive to early detection and qualitative diagnosis of early lung cancer.

  9. SPECT/spiral CT and bone scintigraphy in cancer patients: Impact of a low dose CT acquisitions in indeterminate or suspicious solitary focus; TEMP/TDM et scintigraphie osseuse en cancerologie: impact d'une acquisition scannographique basse dose chez les patients avec foyer isole suspect ou de nature indeterminee

    Energy Technology Data Exchange (ETDEWEB)

    Franson, T.; Bardet, S.; Switsers, O.; Aide, N. [CRLCC Francois-Baclesse, 14 - Caen (France); CHU Lyon-Sud, Pierre-Benite, Service de Medecine Nucleaire, 69 - Lyon (France); Loiseau, C. [CRLCC Francois-Baclesse, Unite de Biophysique, 14 - Caen (France); Allouache, D.; Gunzer, K. [CRLCC Francois-Baclesse, Oncologie Medicale, 14 - Caen (France); Allouache, N. [CRLCC Francois-Baclesse, Radiotherapie, 14 - Caen (France)

    2008-05-15

    Aim: To evaluate the usefulness of a low dose SPECT/CT and the added value of an additional 'diagnostic' centred CT-scan in cancer patients with a solitary focus observed on planar whole-body bone scintigraphy (P.W.B.S.) and classified as indeterminate or suspicious. Material and methods Sixty consecutive patients underwent a low dose SPECT/CT acquisition (120 kV, 30 m As, 3 mm slice thickness) followed by a 'diagnostic' CT-scan (120 kV, 100 m As, 1.25 mm slice thickness) centred on the focus. The first observer considered prospectively W.B.S., low-dose SPECT/CT and finally the centred SPECT/CT. A blinded review was performed by a second observer. Results P.W.B.S. depicted solitary indeterminate or suspicious foci in 38 and 22 patients, respectively. SPECT/CT acquisitions clarified 73% (44/60) of the foci. Additional diagnostic CT-scan altered low-dose SPECT/CT results in nine patients. Additional foci (not found by P.W.B.S.) located outside the scanning area of the centred diagnostic CT-scan were found in 20 patients. Inter observer agreement for P.W.B.S., low-dose SPECT/CT and diagnostic SPECT/CT was equal to 0.542, 0.68 and 0.694, respectively. R.O.C. analysis showed no difference between low-dose SPECT/CT and diagnostic SPECT/CT for observer 1 and observer 2. Conclusion This study shows that a conventional low-dose SPECT/CT in patients presenting with a solitary focus on P.W.B.S. is sufficient to improve both accuracy and inter observer variability of bone scanning. A CT volume session should not be limited to the area of the solitary focus since additional foci located outside the centred CT-scan frequently occurred. (authors)

  10. A Graphical review of radiogenic animal cancer data using the 'dose and dose-rate map'

    International Nuclear Information System (INIS)

    We have been investigating the effects of low dose or low dose rate irradiation on mice, using our low dose-rate irradiation facilities. In these studies, we found that the effects were highly dependent on both total dose and dose rate. To show this visually, we proposed the 'dose and dose-rate map (DDR map),' and plotted the results of our laboratory and our co-workers. The map demonstrated that dose and dose rate plane could be divided into three areas; an area where harmful effects are observed, an area where no harmful effects are observed and another area, between previous two areas, where certain protective functions are enhanced As this map would be a powerful tool to find some trend among the vast numbers of data relating the biological effects of ionizing radiation, we have developed a computer program which plots the collected data on the DDR map sorting by experimental conditions. In this study we graphically reviewed and analyzed the data relating to the lifespan studies of animals with a view to determining the relationships between doses and dose rates of ionizing radiation and cancer incidence. The data contains about 800 sets of experiments, which concerns 187,000 animals exposed to gamma ray or X-ray and their 112,000 controls, and total of about 30,000 cancers in exposed animals and 14,000 cancers in controls. About 800 points of data were plotted on the DDR map. The plot showed that the divided three areas in the DDR map were generally confirmed by these 800 points of data, and in some particular conditions, exempli gratia (e.g.) sarcoma, the biologically effective area is extended to relatively high dose and dose rate area. (author)

  11. [Low dose naltrexone for treatment of pain].

    Science.gov (United States)

    Plesner, Karin Bruun; Vægter, Henrik Bjarke; Handberg, Gitte

    2015-10-01

    Recent years have seen an increasing interest in the use of low dose naltrexone (LDN) for off-label treatment of pain in diseases as fibromyalgia, multiple sclerosis and morbus Crohn. The evidence is poor, with only few randomized double-blind placebo-controlled studies. The studies currently available are reviewed in this paper. LDN could be a potentially useful drug in the future for the treatment of pain in fibromyalgia, but more studies are needed to verify that it is superior to placebo, and currently it cannot be recommended as first-line therapy. PMID:26509454

  12. 4690例无症状健康体检者低剂量CT早期肺癌筛查研究%Results of low-dose computed tomography (LDCT)screening for early lung cancer: prevalence in 4 690 asymptomatic participants

    Institute of Scientific and Technical Information of China (English)

    唐威; 吴宁; 黄遥; 王建卫; 赵世俊; 徐志坚; 张凯; 姜勇; 蔡强

    2014-01-01

    Objective To report the results of low-dose computed tomography (LDCT) screening for early lung cancer in 4 690 asymptomatic participants at the Cancer Hospital,Chinese Academy of Medical Sciences between July 2007 and June 2012.Methods After informed consent and questionnaire forms were obtained,4 690 asymptomatic participants ≥ 40 years underwent chest low dose spiral CT scanning.According to the National Comprehensive Cancer Network (NCCN) guideline for lung cancer screening (version 1.1,2012),all participants were assigned to three groups,namely high-risk,moderaterisk and low-risk groups.In terms of gender,smoking history and second-hand tobacco smoking exposure history,two other groups named male and female never-smoker groups who were exposed to second-hand tobacco smoking were designated.The positive results were identified as at least one solid or part-solid nodule measuring ≥5 mm,or non-solid nodule ≥8 mm in diameter.LDCT scanning protocol,criteria of management according to the size and consistency of pulmonary nodules were compliant with the International Early Lung Cancer Active Program (I-ELCAP).TNM staging of all lung cancers were based on the clinical evidence and pathological findings.Results In various risk status group of the participants,the percentage of positive results of baseline CT were 27.0% (86/319),19.3 % (199/1 029) and 11.3 % (377/3 342),respectively.A total of 26 participants (27 lesions) were diagnosed as lung cancer (11 in men,15 in women).The detection rate of lung cancer was 0.6% (26/4 690).Besides a SCLC (limited-disease,LD),25 cases (76.0%) were stage Ⅰ including 24 NSCLC and one cacinoid on baseline LDCT and the surgical resection rate was 88.5% (23/26).The diameter of resected cancers was 6.9-29.5 mm (median,16.3 mm).For female never smokers aged 40 years or older who were exposed to second-hand smoking,the detection rate of lung cancer was higher than that of the high-risk and male never smokers who were

  13. Locoregional IL-2 low dose applications for gastrointestinal tumors

    Institute of Scientific and Technical Information of China (English)

    Zachary Krastev; Willem Den Otter; V Koltchakov; R Tomova; S Deredjian; A Alexiev; D Popov; B Tomov; Jan-Willem Koten; John Jacobs

    2005-01-01

    AIM: To explore the feasibility of local interleukin 2 (IL-2)in patients with different forms of abdominal cancer. This required experimentation with the time interval between IL-2 applications and the methods of application.METHODS: Sixteen patients with stages Ⅲ and Ⅳ of gastrointestinal malignancies (primary or metastatic) who were admitted to our Department of Gastroenterology were treated with locoregionally applied IL-2 in low doses.RESULTS: No major problems applying locoregional IL-2 were encountered. In 6 out of 16 patients, a modest but clinically worthwhile improvement was obtained. Adverse effects were minimal, The therapeutic scheme was well tolerated, even in patients in a poor condition.CONCLUSION: This study demonstrates the feasibility of low dose locoregional IL-2 application in advanced abdominal cancer. Local IL-2 therapy gives only negligible adverse effects. The results suggest that it is important to apply intratumorally. Local IL-2 may be given adjunct to standard therapeutic regimes and does not imply complex surgical interventions. These initial results are encouraging.

  14. Does cancer affect the divorce rate?

    Directory of Open Access Journals (Sweden)

    Øystein Kravdal

    2007-06-01

    Full Text Available Discrete-time hazard regression models were employed to register and census data on 1.4 million Norwegian married couples from 1974-2001 to explore the probability of divorce following cancer illness. Divorce rates for around 215 000 persons diagnosed with cancer were compared to divorce rates for persons for whom all the other observed variables were the same. No overall harmful influence of a cancer diagnosis was observed. Most cancer forms resulted in small, immediate declines in divorce rates the first years following diagnosis. Exceptions were significant increases in the divorce rates for persons diagnosed with cervical and testicular cancer.

  15. Automated detection and classification of interstitial lung diseases from low-dose CT images

    Science.gov (United States)

    Zheng, Bin; Leader, Joseph K.; Fuhrman, Carl R.; Sciurba, Frank C.; Gur, David

    2004-05-01

    We developed a computer-aided diagnosis (CAD) scheme to detect and quantitatively assess interstitial lung diseases (ILD) depicted on low-dose and multi-slice helical high-resolution computed tomography (CT) examinations. Eighteen CT cases acquired from patients who underwent routine low-dose whole-lung screening examinations for the detection of lung cancer were used to test the scheme. ILD was identified in all of these cases. The CAD scheme involves multiple steps to segment lung areas, identify suspicious ILD regions depicted on each CT slice, and generate volumetric ILD lesions by grouping and matching ILD regions detected on multiple adjacent slices. The scheme computes five "global" features for each identified ILD region, which include size (or volume), contrast, average local pixel value fluctuation, mean of stochastic fractal dimension, and geometric fractal dimension. Two sets of classification rules are applied to remove false-positive detections. The severity of ILD in each case was rated by one experienced chest radiologist into one of the three categories (mild, moderate, and severe). A distance-weighted k-nearest neighbor algorithm and round-robin validation method was applied to classify each testing case into one of the three categories of severity. In this experiment, the CAD scheme classified 78% (14 out of 18) cases into the same categories as rated by the radiologist.

  16. Nuclear energy and health: and the benefits of low-dose radiation hormesis.

    Science.gov (United States)

    Cuttler, Jerry M; Pollycove, Myron

    2009-01-01

    Energy needs worldwide are expected to increase for the foreseeable future, but fuel supplies are limited. Nuclear reactors could supply much of the energy demand in a safe, sustainable manner were it not for fear of potential releases of radioactivity. Such releases would likely deliver a low dose or dose rate of radiation, within the range of naturally occurring radiation, to which life is already accustomed. The key areas of concern are discussed. Studies of actual health effects, especially thyroid cancers, following exposures are assessed. Radiation hormesis is explained, pointing out that beneficial effects are expected following a low dose or dose rate because protective responses against stresses are stimulated. The notions that no amount of radiation is small enough to be harmless and that a nuclear accident could kill hundreds of thousands are challenged in light of experience: more than a century with radiation and six decades with reactors. If nuclear energy is to play a significant role in meeting future needs, regulatory authorities must examine the scientific evidence and communicate the real health effects of nuclear radiation. Negative images and implications of health risks derived by unscientific extrapolations of harmful effects of high doses must be dispelled.

  17. [Complications of low-dose amiodarone].

    Science.gov (United States)

    Feigl, D; Gilad, R; Katz, E

    1991-11-15

    Complications of low-dose amiodarone in 83 patients, in whom the drug was effective and who were followed for 1-13 years, are presented. Hypothyroidism was diagnosed in 11 (in 8 by the finding of elevated TSH). In 2 of the 3 in whom clinical signs of hypothyroidism were evident, amiodarone was continued, but thyroxine was also given. In 5 others thyrotoxicosis ensued. Propylthiouracil (PTU) was given and amiodarone was discontinued. PTU was then stopped within 4-8 months, without recurrence of the hyperthyroidism. In 1 patient pneumonitis resolved spontaneously a few weeks after stopping amiodarone. Because of gastrointestinal distress amiodarone was stopped in 1 patient. In none were liver enzymes elevated, nor was the nervous system affected clinically. Photosensitivity in 6 patients and skin discoloration in 2 did not necessitate discontinuation of the drug. Blurred vision was reported by 4, but its connection with amiodarone was not proven. There was sinus bradycardia in 2. There was no arrhythmic effect of amiodarone seen on ECG nor on Holter monitoring, nor was there any mortality. We conclude that amiodarone in low doses causes many complications, most of them mild and transient. However, in only a few cases is discontinuation of the drug indicated. PMID:1752553

  18. Low dose spinal anesthesia for knee arthroscopy

    Directory of Open Access Journals (Sweden)

    Lakhin R.E.

    2015-06-01

    Full Text Available Objective: to evaluate the nature of unilateral spinal anesthesia using various modes of administration of low doses of hyperbaric bupivacaine. Materials and Methods. Prospectively, the randomized study included 56 patients undergoing knee arthroscopy. In the control group bupivacaine of 5mg was administered simultaneously, in the main group — fractionally by 2.5 mg. The development of thermal and pain blocks from different sides was investigated. The data were statistically processed. Results. In the control group, the positioning of the patient usually began after the entire dose of anesthetic had been administered. In the case of temperature paresthesia in the area of the sacral segments of the full anesthesia throughout underlying limb was not always achieved. In 6 cases of block was not sufficient. In the main group patient positioning was performed after the administration of 2.5 mg of anesthetic and evaluate temperature paresthesia and in 2 cases the total dose was increased to 7.5 mg. The successful development of sensory block at fractional administration was significantly higher than in the single-step introduction. Conclusion. Temperature paresthesia occurs within the first minute and is an early predictor of developing spinal anesthesia. The area of arising paresthesia shows preferential distribution of the anesthetic. In the application of low dose local anesthetic the desired upper level of anesthesia via the patient positioning and dose adjustment may be achieved.

  19. 多层螺旋CT低剂量扫描在监测早期肺癌动态进展的应用价值研究%Evaluation of low-dose multislice spiral CT scanning in monitoring the dynamic progress of patients with lung cancer at early stage

    Institute of Scientific and Technical Information of China (English)

    邢雪莲

    2013-01-01

    Objective To investigate the value of multislice spiral CT ( MSCT ) low dose scanning in the monitoring of dynamic progress of patients with lung cancer at early stage. Methods 300 patients with lung cancer at early stage were closely followed-up, and their ordinary CT and low-dose CT image characteristics were analyzed. Results 1. In the diagnosis of early lung cancer respectively for the diameter less than 5mm, 5-10mm and greater than 10mm, there was no significant difference between the ordinary CT scan and the low-dose CT scan diagnosis ( P >0. 05 ). 2. In the follow-ups, there were 31 lesions without significant change, and 90 lesions became larger, 12 lesions of which had metastasis. Conclusion Multislice spiral CT scanning can relatively detect lung cancer lesions earlier and cause smaller radiation damage.%目的 探讨多层螺旋CT低剂量扫描在监测早期肺癌动态进展的价值.方法 对300例早期肺癌患者密切随访,分析其普通CT及低剂量CT图像特点.结果 (1)在直径小于5 mm,5~10 mm及大于10 mm的早期肺癌诊断中,普通CT与低剂量CT诊断符合率间无统计学差异(P>0.05).(2)随访过程中,31例病灶无明显变化,90例病灶径线变大.其中12例病灶出现转移.结论 多层螺旋CT低剂量扫描能够早期发现肺癌病灶,对受检者辐射损伤小,具有较高的应用价值.

  20. Application Value of Low-dose Computed Tomography for the Screening of Lung-cancer in High-risk Group%低剂量计算机断层成像在高危人群早期肺癌筛查中的价值研究

    Institute of Scientific and Technical Information of China (English)

    雷弋; 陈勃江; 曾莉; 李为民

    2012-01-01

    目的 研究低剂量计算机断层成像(low-dose computed tomography,LDCT)在高危人群早期肺癌筛查中的价值,寻找可行的肺癌筛查方法.方法 对2007年1~12月在四川大学华西医院体检中心参加团体健康体检的40岁以上体检者共1551例(男性1054例,女性497例)进行LDCT检查,根据高危因素分为高危组和非高危组并对检查发现的肺部病变及肺癌检出情况进行分析.结果 LDCT在40岁以上体检人群中肺部病变的检出率为54.41% (844/1551);结节病变检出率29.40%(456/1551).LDCT在40岁以上体检人群、肺癌高危人群及高危吸烟人群中肺癌检出率分别为0.51%(8/1551)、1.21%(7/577)和2.01%(6/298),后两者分别与前者比较,差异有统计学意义(P<0.05).LDCT在无危险凶素人群肺癌检出率为0.10%(1/974),有一个危险因素的人群肺癌检出率为0.98%(5/506),有两个危险因素的人群肺癌检出率为2.86%(2/70),3组间差异有统计学意义(P<0.05).结论 LDCT在降低辐射剂量的同时,能敏感地检出无症状的肺癌,可望成为我国肺癌筛查的方法之一.%Objective To analyze the value of low-dose computed tomography (LDCT) in early screening of lung cancer in high-risk group. Methods LDCT was performed in 1551 adults over 40-years old (male 1054 ,female 497) for the screening of lung cancer in Examination Center of West China Hospital, Sichuan University, and the subjects were divided into high-risk group and non-high-risk group according to risk factors of lung caner. The detection rates of lung lesion and lung cancer in these two groups were carefully analyzed. Results In the people over 40-years old,the detection rate of pulmonary lesions by LDCT was 54. 41% (844/1551), the detection rate of nodules was 29. 4% (456/1551). Detection rate of lung cancer was 0. 51 % (8/1551), while it was 1.21% (7/577) in high-risk group, and 2. 01% (6/298) in heavy smoker group. The difference of lung cancer

  1. Molecular targets for radioprotection by low dose radiation exposure

    International Nuclear Information System (INIS)

    Adaptive response is a reduced effect from a higher challenging dose of a stressor after a smaller inducing dose had been applied a few hrs earlier. Radiation induced fibrosarcoma (RIF) cells did not show such an adaptive response, i.e. a reduced effect from a higher challenging dose (2 Gy) of a radiation after a priming dose (1 cGy) had been applied 4 or 7 hrs earlier, but its thermoresistant clone (TR) did. Since inducible HSP70 and HSP25 expressions were different between these two cell lines, the role of inducible HSP70 and HSP25 in adaptive response was examined. When inducible hsp70 or hsp25 genes were transfected to RIF cells, radioresistance in clonogenic survival and reduction of apoptosis was detected. The adaptive response was also acquired in these two cell lines, and inducible hsp70 transfectant showed more pronounced adaptive response than hsp25 transfectant. From these results, inducible HSP70 and HSP25 are at least partly responsible for the induction of adaptive response in these cells. Moreover, when inducible HSP70 or HSP25 genes were transfected to RIF cells, coregulation of each gene was detected and heat shock factor (HSF) was found to be responsible for these phenomena. In continuation of our earlier study on the involvement of heat shock protein (HSP) 25 and HSP70 in the induction of adaptive response, we have now examined the involvement of these proteins in the induction of the adaptive response, using an animal model system. C57BL6 mice were irradiated with 5 cGy of gamma radiation 3 times for a week (total of 15cGy) and a high challenge dose (6Gy) was given on the day following the last low dose irradiation. Survival rate of the low dose pre-irradiated mice was increased to 30%. Moreover, high dose-mediated induction of apoptosis was also reduced by low dose pre-irradiation. To elucidate any link existing between HSP and induction of the adaptive response, reverse transcriptase (RT)-polymerase chain reaction (PCR) analysis was performed

  2. 低剂量健择同步高-低氧放射治疗局部晚期胰腺癌的临床价值%Value of low doses of gemcitabine chemotherapy combined with high-low oxygen radiotherapy synchronously for therapy of patients with locally advanced pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    丁兆军; 孙衍伟; 陈希平; 安永恒

    2012-01-01

    Objective To evaluate the efficacy and adverse effects of low doses gemcitabine chemotherapy combined with synchronous high-low oxygen radiotherapy in patients with locally advanced pancreatic cancer.Methods Fifty-six patients with locally advanced pancreatic cancer were randomly divided into two groups by envelop method:radio-chemotherapy group or chemotherapy group.Patients in radio-chmotherapy group were treated with low doses of gemcitabine chemotherapy ( 600 mg/m2 ) combined with high-low oxygen radiotherapy synchronously,paients in chmotherapy group were treated with full doses of gemcitabine chemotherapy ( 1000 mg/m2).The short-term effect,distant metastasis rate,clinical benefit rate,survival rate and adverse events of two groups were observed.Results There was one patient achievedcomplete relief and 15 patients achieved partial relief in radio-chemotherapy group with an overall effective rate of 66.7% (16/24) ; there were 9 patients achieved partial relief in chemotherapy group with an overall effective rate of 36.0% (9/25),the difference between the two groups was statistically significant (X2 =4.6082,P =0.0318 ).The clinical benefit rates were 83.3 % ( 20/24 ) and 60% ( 15/25 ),respectively,the difference between the two groups was not statistically significant ( P =0.070).The distant metastasis rates were 66.7%(16/24) and 72% (18/25),respectively,the difference between the two groups was not statistically significant (P =0.6855).The 12,24 months survival rates were 62.5% vs 32%,37.5% vs 12%,the difference between the two groups was statistically significant ( P =0.0325,0.0380).The incidence of serious adverse events was 45.8% and 4 0 % without statistical difference.Conclusions Low doses of gemcitabine chemotherapy combined with high-low oxygen radiotherapy synchronously is better than full doses of gemcitabine chemotherapy with regard to total effective rates and 12,24 months survival rates,with no obvious increase in the

  3. From Chernobyl to Fukushima: the effect of low doses

    International Nuclear Information System (INIS)

    This Power Point presentation describes the Fukushima's reactors, recalls some data about the earthquake and tsunami, and indicates their consequences for the operation of the power station (notably the loss of cooling means). It identifies some design errors for the Chernobyl's and Fukushima's power stations, outlines differences between these two cases. It gives assessment of doses receives by external irradiation around Fukushima, of the dose rate evolution, of the sea contamination. It gives some data about the Chernobyl accident (radioactivity evolution). After some data about health consequences of Chernobyl, health risks and more particularly biological risks associated to low doses are described. Protection measures are evoked, as well as psycho-social impacts

  4. Declining death rates reflect progress against cancer.

    Directory of Open Access Journals (Sweden)

    Ahmedin Jemal

    Full Text Available BACKGROUND: The success of the "war on cancer" initiated in 1971 continues to be debated, with trends in cancer mortality variably presented as evidence of progress or failure. We examined temporal trends in death rates from all-cancer and the 19 most common cancers in the United States from 1970-2006. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed trends in age-standardized death rates (per 100,000 for all cancers combined, the four most common cancers, and 15 other sites from 1970-2006 in the United States using joinpoint regression model. The age-standardized death rate for all-cancers combined in men increased from 249.3 in 1970 to 279.8 in 1990, and then decreased to 221.1 in 2006, yielding a net decline of 21% and 11% from the 1990 and 1970 rates, respectively. Similarly, the all-cancer death rate in women increased from 163.0 in 1970 to 175.3 in 1991 and then decreased to 153.7 in 2006, a net decline of 12% and 6% from the 1991 and 1970 rates, respectively. These decreases since 1990/91 translate to preventing of 561,400 cancer deaths in men and 205,700 deaths in women. The decrease in death rates from all-cancers involved all ages and racial/ethnic groups. Death rates decreased for 15 of the 19 cancer sites, including the four major cancers, with lung, colorectum and prostate cancers in men and breast and colorectum cancers in women. CONCLUSIONS/SIGNIFICANCE: Progress in reducing cancer death rates is evident whether measured against baseline rates in 1970 or in 1990. The downturn in cancer death rates since 1990 result mostly from reductions in tobacco use, increased screening allowing early detection of several cancers, and modest to large improvements in treatment for specific cancers. Continued and increased investment in cancer prevention and control, access to high quality health care, and research could accelerate this progress.

  5. Low Dose Ionizing Radiation Modulates Immune Function

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Gregory A. [Loma Linda Univ., CA (United States)

    2016-01-12

    In order to examine the effects of low dose ionizing radiation on the immune system we chose to examine an amplified adaptive cellular immunity response. This response is Type IV delayed-type hypersensitivity also called contact hypersensitivity. The agent fluorescein isothiocyanate (FITC) is a low molecular weight, lipophilic, reactive, fluorescent molecule that can be applied to the skin where it (hapten) reacts with proteins (carriers) to become a complete antigen. Exposure to FITC leads to sensitization which is easily measured as a hypersensitivity inflammatory reaction following a subsequent exposure to the ear. Ear swelling, eosinophil infiltration, immunoglobulin E production and cytokine secretion patterns characteristic of a “Th2 polarized” immune response are the components of the reaction. The reaction requires successful implementation of antigen processing and presentation by antigen presenting Langerhans cells, communication with naïve T lymphocytes in draining lymph nodes, expansion of activated T cell clones, migration of activated T cells to the circulation, and recruitment of memory T cells, macrophages and eosinophils to the site of the secondary challenge. Using this model our approach was to quantify system function rather than relying only on indirect biomarkers of cell. We measured the FITC-induced hypersensitivity reaction over a range of doses from 2 cGy to 2 Gy. Irradiations were performed during key events or prior to key events to deplete critical cell populations. In addition to quantifying the final inflammatory response, we assessed cell populations in peripheral blood and spleen, cytokine signatures, IgE levels and expression of genes associated with key processes in sensitization and elicitation/recall. We hypothesized that ionizing radiation would produce a biphasic effect on immune system function resulting in an enhancement at low doses and a depression at higher doses and suggested that this transition would occur in the

  6. Low doses of neutrons induce changes in gene expression

    International Nuclear Information System (INIS)

    Studies were designed to identify genes induced following low-dose neutron but not following γ-ray exposure in fibroblasts. Our past work had shown differences in the expression of β-protein kinase C and c-fos genes, both being induced following γ-ray but not neutron exposure. We have identified two genes that are induced following neutron, but not γ-ray, exposure: Rp-8 (a gene induced by apoptosis) and the long terminal repeat (LTR) of the human immunodeficiency (HIV). Rp-8 mRNA induction was demonstrated in Syrian hamster embryo fibroblasts and was found to be induced in cells exposed to neutrons administered at low (0.5 cGy/min) and at high dose rate (12 cGy/min). The induction of transcription from the LTR of HIV was demonstrated in HeLa cells bearing a transfected construct of the chloramphenicol acetyl transferase (CAT) gene driven by the HIV-LTR promoter. Measures of CAT activity and CAT transcripts following irradiation demonstrated an unresponsiveness to γ rays over a broad range of doses. Twofold induction of the HIV-LTR was detected following neutron exposure (48 cGy) administered at low (0.5 cGy/min) but not high (12 cGy/min) dose rates. Ultraviolet-mediated HIV-LTR induction was inhibited by low-dose-rate neutron exposure

  7. Cancer rates after kidney transplantation

    DEFF Research Database (Denmark)

    Sodemann, Ulrik; Bistrup, Claus; Marckmann, Peter

    2011-01-01

    Previous studies demonstrated a 3-5-fold increased cancer risk in kidney allograft recipients compared with the general population. Our aim was to estimate cancer frequencies among kidney allograft recipients who were transplanted in 1997-2000 and who were immunosuppressed according to a more...

  8. Transcriptome profiling of mice testes following low dose irradiation

    DEFF Research Database (Denmark)

    Belling, Kirstine C.; Tanaka, Masami; Dalgaard, Marlene Danner;

    2013-01-01

    cell types of the adult testis. We observed large expression changes in the somatic cell profile, which mainly could be attributed to changes in cellularity, but hyperplasia of Leydig cells may also play a role. We speculate that the possible hyperplasia may be caused by lower testosterone production......ABSTRACT: BACKGROUND: Radiotherapy is used routinely to treat testicular cancer. Testicular cells vary in radio-sensitivity and the aim of this study was to investigate cellular and molecular changes caused by low dose irradiation of mice testis and to identify transcripts from different cell types...... in the adult testis. METHODS: Transcriptome profiling was performed on total RNA from testes sampled at various time points (n = 17) after 1 Gy of irradiation. Transcripts displaying large overall expression changes during the time series, but small expression changes between neighbouring time points were...

  9. The spectrum of mutation produced by low dose radiation

    Energy Technology Data Exchange (ETDEWEB)

    Morley,Alexander,A; Turner, David,R

    2004-10-31

    Inherited mutations are the basis of evolution and acquired mutations in humans are important in ageing, cancer and possibly various forms of tissue degeneration. Mutations are responsible for many of the long-term effects of radiation. However, sensitive direct detection of mutations in humans has been difficult. The aims of the project were to develop methods for the sensitive enumeration of mutations in DNA, to measure mutation frequencies in a wide variety of tissue types and to quantify the mutational effect of direct oxidative damage produced by radiation, at both high and low doses. The project was successful in developing a sensitive method which could detect mutations directly in the genetic material, DNA at a sensitivity of 1 mutated molecule in 1000000000 unmutated molecules. However a number of methodological problems had to be overcome and lack of ongoing funding made it impossible to fulfill all of the aims of the project

  10. The Inhibitory Effects of Low-Dose Ionizing Radiation in IgE-Mediated Allergic Responses.

    Directory of Open Access Journals (Sweden)

    Hae Mi Joo

    Full Text Available Ionizing radiation has different biological effects according to dose and dose rate. In particular, the biological effect of low-dose radiation is unclear. Low-dose whole-body gamma irradiation activates immune responses in several ways. However, the effects and mechanism of low-dose radiation on allergic responses remain poorly understood. Previously, we reported that low-dose ionizing radiation inhibits mediator release in IgE-mediated RBL-2H3 mast cell activation. In this study, to have any physiological relevance, we investigated whether low-dose radiation inhibits allergic responses in activated human mast cells (HMC-1(5C6 and LAD2 cells, mouse models of passive cutaneous anaphylaxis and the late-phase cutaneous response. High-dose radiation induced cell death, but low-dose ionizing radiation of <0.5 Gy did not induce mast cell death. Low-dose ionizing radiation that did not induce cell death significantly suppressed mediator release from human mast cells (HMC-1(5C6 and LAD2 cells that were activated by antigen-antibody reaction. To determine the inhibitory mechanism of mediator released by low-dose ionizing radiation, we examined the phosphorylation of intracellular signaling molecules such as Lyn, Syk, phospholipase Cγ, and protein kinase C, as well as the intracellular free Ca2+ concentration ([Ca2+]i. The phosphorylation of signaling molecules and [Ca2+]i following stimulation of FcεRI receptors was inhibited by low dose ionizing radiation. In agreement with its in vitro effect, ionizing radiation also significantly inhibited inflammatory cells infiltration, cytokine mRNA expression (TNF-α, IL-4, IL-13, and symptoms of passive cutaneous anaphylaxis reaction and the late-phase cutaneous response in anti-dinitrophenyl IgE-sensitized mice. These results indicate that ionizing radiation inhibits both mast cell-mediated immediate- and delayed-type allergic reactions in vivo and in vitro.

  11. Low dose radiation enhances the Locomotor activity of D. melanogaster

    Energy Technology Data Exchange (ETDEWEB)

    Seong, Ki Moon; Lee, Buyng Sub; Nam Seon Young; Kim, Ji Young; Yang, Kwang Hee; Choi, Tae In; Kim, Cha Soon [Radiation Effect Research Team, Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., Gyeongju (Korea, Republic of)

    2013-04-15

    Mild stresses at low level including radiation can induce the beneficial effects in many vertebrate and invertebrate species. However, a large amount of studies in radiation biology have focused on the detrimental effects of high dose radiation (HDR) such as the increased incidence of cancers and developmental diseases. Low dose radiation (LDR) induces biologically favorable effects in diverse fields, for example, cancer development, genomic instability, immune response, and longevity. Our previous data indicated that LDR promotes cells proliferation of which degree is not much but significant, and microarray data explained that LDR irradiated fruit flies showing the augmented immunity significantly changed the program for gene expression of many genes in Gene Ontology (GO) categories related to metabolic process. Metabolic process in development one of major contributors in organism growth, interbreeding, motility, and aging. Therefore, it is valuable to examine whether LDR change the physiological parameters related to metabolism, and how LDR regulates the metabolism in D. melanogaster. In this study, to investigate that LDR influences change of the metabolism, a representative parameter, locomotor activity. In addition, the activation of several cellular signal molecules was determined to investigate the specific molecular mechanism of LDR effects on the metabolism. We explored whether ionizing radiation affects the motility activity. We performed the RING assays to evaluate the locomotor activity, a representative parameter presenting motility of fruit flies. HDR dramatically decreased the motor activity of irradiated flies. Surprisingly, the irradiated flies at low dose radiation in both acute and chronic showed the significantly increased locomotor activity, compared to non-irradiated flies. Irradiation would induce change of the several signal pathways for flies to respond to it. The activation of some proteins involved in the cells proliferation and stress

  12. low dose irradiation growth in zirconium

    International Nuclear Information System (INIS)

    Low dose neutron irradiation growth in textured and recrystallized zirconium, is studied, at the Candu Reactors Calandria temperature (340 K) and at 77 K. It was necessary to design and build 1: A facility to irradiate at high temperatures, which was installed in the Argentine Atomic Energy Commission's RA1 Reactor; 2: Devices to carry out thermal recoveries, and 3: Devices for 'in situ' measurements of dimensional changes. The first growth kinetics curves were obtained at 365 K and at 77 K in a cryostat under neutron fluxes of similar spectra. Irradiation growth experiments were made in zirconium doped with fissionable material (0,1 at %235U). In this way an equivalent dose two orders of magnitude greater than the reactor's fast neutrons dose was obtained, significantly reducing the irradiation time. The specimens used were bimetallic couples, thus obtaining a great accuracy in the measurements. The results allow to determine that the dislocation loops are the main cause of irradiation growth in recrystallized zirconium. Furthermore, it is shown the importance of 'in situ' measurements as a way to avoid the effect that temperature changes have in the final growth measurement; since they can modify the residual stresses and the overconcentrations of defects. (M.E.L.)

  13. Contraception. Low-dose pill launched.

    Science.gov (United States)

    1993-01-01

    At a vibrant ceremony in Kampala, Uganda, the Minister of Women in Development, Youth and Culture launched the new low-dose oral contraceptive Pilplan which provides women more options for birth spacing. Diplomats, physicians, government officials, and business leaders attended the ceremony at the Sheraton Hotel Kampala. A dance group did an interpretation of "Women in Uganda: Gaining Momentum." The Minister considered the introduction of this new pill as a turning point for reproductive rights. A baseline survey among Ugandan women has shown that although almost all women were familiar with the pill, only 36% have ever used it and only 15% were currently using it. 80% thought that pill use was preferable to having an unplanned pregnancy. These findings convinced the Minister that ignorance and misconception keep women from using the pill. The government, health providers, and others need to educate women about Pilplan and how to use it correctly. A bilateral agreement between the Ministry of Health and USAID set in motion a social marketing project which has now launched two contraceptive methods: Pilplan in 1993 and the Protector condom in 1990. USAID vowed to continue to support Pilplan, particularly if men could also help in supporting birth spacing. A Uganda-based pharmaceutical firm will distribute Pilplan in Uganda through pharmacies, clinics, and health facilities. Pilplan targets all middle- to low-income women. PMID:12319754

  14. Liver cancer mortality rate model in Thailand

    Science.gov (United States)

    Sriwattanapongse, Wattanavadee; Prasitwattanaseree, Sukon

    2013-09-01

    Liver Cancer has been a leading cause of death in Thailand. The purpose of this study was to model and forecast liver cancer mortality rate in Thailand using death certificate reports. A retrospective analysis of the liver cancer mortality rate was conducted. Numbering of 123,280 liver cancer causes of death cases were obtained from the national vital registration database for the 10-year period from 2000 to 2009, provided by the Ministry of Interior and coded as cause-of-death using ICD-10 by the Ministry of Public Health. Multivariate regression model was used for modeling and forecasting age-specific liver cancer mortality rates in Thailand. Liver cancer mortality increased with increasing age for each sex and was also higher in the North East provinces. The trends of liver cancer mortality remained stable in most age groups with increases during ten-year period (2000 to 2009) in the Northern and Southern. Liver cancer mortality was higher in males and increase with increasing age. There is need of liver cancer control measures to remain on a sustained and long-term basis for the high liver cancer burden rate of Thailand.

  15. The MAGIC-5 CAD for nodule detection in low dose and thin slice lung CTs

    International Nuclear Information System (INIS)

    Lung cancer is the leading cause of cancer-related mortality in developed countries. Only 10-15% of all men and women diagnosed with lung cancer live 5 years after the diagnosis. However, the 5-year survival rate for patients diagnosed in the early asymptomatic stage of the disease can reach 70%. Early-stage lung cancers can be diagnosed by detecting non-calcified small pulmonary nodules with computed tomography (CT). Computer-aided detection (CAD) could support radiologists in the analysis of the large amount of noisy images generated in screening programs, where low-dose and thin-slice settings are used. The MAGIC-5 project, funded by the Istituto Nazionale di Fisica Nucleare (INFN, Italy) and Ministero dell'Universita e della Ricerca (MUR, Italy), developed a multi-method approach based on three CAD algorithms to be used in parallel with a merging of their results: the Channeler Ant Model (CAM), based on Virtual Ant Colonies, the Dot-Enhancement/Pleura Surface Normals/VBNA (DE-PSN-VBNA), and the Region Growing Volume Plateau (RGVP). Preliminary results show quite good performances, to be improved with the refining of the single algorithm and the added value of the results merging.

  16. Low-dose 64- MDCT urography in nonmalignant kidney diseases

    International Nuclear Information System (INIS)

    distance. And as for the effective dose is mean absorbed dose from a uniform wholebody irradiation that results in the same total radiation detriment as from the nonuniform, partial-body irradiation in question. CT manufacturers apply a number of technical innovations for dose reduction comprising x-ray filtration, automatic modulation of tube current, reconstruction algorithms and prevention from Over ranging (over scanning). Our 64 sliced CT scanner has most of these innovations, but in most cases local optimization of scanning protocols is possible. To reduce the dose we used lower kVp and eff mAs keeping other scanning parameters unchanged. As you can see from the diagram there are significant differences between the two protocols, up to 50% dose reduction in measurable quantities CTDI and DLP and up to 46 % reduction in effective dose which is estimation of radiation risk. At the same time the images obtained with the new low dose protocol have maintained their quality. Discussion: More recently, clinical and ex vivo porcine phantom studies have evaluated a low-dose MDCT protocol using low tube charge current (≤30 mAs), which delivers a dose of radiation close to that delivered by abdominal radiography. Such low-dose CT protocols resulted in a substantial reduction (50%) of radiation dose when compared with initial management with abdominal radiography and sonography, by reducing the need for further standard-dose CT Reducing kVp 140kVp of 120 kVp may lead to a reduction in the dose to the skin by about 33%. And if you reduce to 80 kVp, the rates will be about 70%. The another way to reduce the radiation dose during CT examination is reducing the number of phases of the study. But in 2005, Walter J. and authors report that the elimination of the unenhanced scans is generally not recommended. Conclusion: As conclusion we can say that the CTU is detailed examination of the urinary tract. But it should be performed only in the cases where is clinically required

  17. Cancer-specific incidence rates of tuberculosis

    Science.gov (United States)

    Seo, Gi Hyeon; Kim, Min Jae; Seo, Soyoung; Hwang, Boram; Lee, Eugene; Yun, Yujin; Choi, Minsun; Kim, Moonsuk; Kim, Jin Won; Kim, Eu Suk; Kim, Hong Bin; Song, Kyoung-Ho

    2016-01-01

    Abstract Population-based studies of the incidence of tuberculosis in cancer patients according to the type of cancer are limited. We investigated the cancer-specific incidence of tuberculosis in a nationwide population-based cohort in a country with an intermediate burden of tuberculosis. We used mandatory National Health Insurance claims data to construct a cancer cohort of adults (aged 20–99 years) with newly diagnosed malignancies other than lung cancer, from January 2008 to December 2012. Patients who developed tuberculosis in this period were identified in the cancer cohort and the general population. Standardized incidence ratios (SIRs) of tuberculosis in the cancer cohort according to type of cancer and time after cancer diagnosis were calculated by comparing the observed incidence rates with those inferred from the age- and gender-specific incidence rates in the general population. A total of 855,382 cancer patients and 1589,876 person-years (py) were observed. A total of 5745 patients developed tuberculosis; the mean incidence rate was 361.3 per 100,000 py, and the SIR was 2.22 (95% confidence interval [CI], 2.17–2.27). The incidence rate was highest for hematologic malignancy and lowest for thyroid cancer. It was also highest as 650.1 per 100,000 py, with SIR of 3.70 (CI, 3.57–3.83) for the first 6 months after diagnosis of malignancy and then declined. However, it still remained higher than that of the general population after 24 months (SIR = 1.43, CI, 1.36–1.51). The incidence of tuberculosis increases after diagnosis in patients with malignancies. The risk of tuberculosis differs according to the type of cancer and remains elevated even 24 months after cancer diagnosis. Tuberculosis should be considered an important comorbidity in patients with malignancies. PMID:27661041

  18. Induction gemcitabine in standard dose or prolonged low-dose with cisplatin followed by concurrent radiochemotherapy in locally advanced non-small cell lung cancer: a randomized phase II clinical trial

    International Nuclear Information System (INIS)

    The optimal combination of chemotherapy with radiation therapy for treatment locally advanced non-small cell lung cancer (NSCLC) remains an open issue. This randomized phase II study compared gemcitabine in two different schedules and cisplatin - as induction chemotherapy, followed by radiation therapy concurrent with cisplatin and etoposid. Eligible patients had microscopically confirmed inoperable non-metastatic non-small cell lung cancer; fulfilled the standard criteria for platin-based chemotherapy; and signed informed consent. Patients were treated with 3 cycles of induction chemotherapy with gemcitabine and cisplatin. Two different aplications of gemcitabine were compared: patients in arm A received gemcitabine at 1250 mg/m2 in a standard half hour i.v. infusion on days 1 and 8; patients in arm B received gemcitabine at 250 mg/m2 in prolonged 6-hours i.v. infusion on days 1 and 8. In both arms, cisplatin 75 mg/m2 on day 2 was administered. All patients continued treatment with radiation therapy with 60–66 Gy concurrent with cisplatin 50 mg/m2 on days 1, 8, 29 and 36 and etoposid 50 mg/m2 on days 1–5 and 29–33. The primary endpoint was response rate (RR) after induction chemotherapy; secondary endpoints were toxicity, progression-free survival (PFS) and overall survival (OS). From September 2005 to November 2010, 106 patients were recruited to this study. No statistically signifficant differences were found in RR after induction chemotherapy between the two arms (48.1% and 57.4%, p = 0.34). Toxicity profile was comparable and mild with grade 3/4 neutropenia as primary toxicity in both arms. One patient in arm B suffered from acute peripheral ischemia grade 4 and an amputation of lower limb was needed. With a median follow-up of 69.3 months, progression-free survival and median survival in arm A were 15.7 and 24.8 months compared to 18.9 and 28.6 months in arm B. The figures for 1- and 3-year overall survival were 73.1% and 30.8% in arm A, and 81.5 % and

  19. Gamma ray radiation induced visible light absorption in P-doped silica fibers at low dose levels

    CERN Document Server

    Lu Ping; Kulkarni, N S; Brown, K

    1999-01-01

    A CCD Fiber Optic Spectrometer has been used to monitor the gamma ray radiation induced loss in P-doped fibers at different dopant concentrations (1, 5 and 10 mol%) with a light source (an incandescent bulb with a temperature of 2800-3000 K). The range of dose rates is limited to that used in medical applications (cancer treatments), that is 0.1 to 1.0 Gray per minute (Gy/min). At low integral dose level (<2.0 Gy) four absorption peaks were observed (470, 502, 540 and 600 nm) within the visible region. It has been observed that the radiation induced loss at 470 and 600 nm depends strongly on dose rate. At dose rates of 0.2 and 0.5 Gy/min the induced loss shows nonlinear relation to the total dose. However, at high dose rate (1.0 Gy/min) and low dose rate (0.1 Gy/min) it seems to have a linear dependence with total dose. The conversion from NBOHCs to GeX centers was observed during gamma radiation at low dose rates (0.1-0.5 Gy/min). At the wavelength of 502 and 540 nm, the radiation induced losses show exce...

  20. The combination of a low-dose chemotherapeutic agent, 5-fluorouracil, and an adenoviral tumor vaccine has a synergistic benefit on survival in a tumor model system.

    Directory of Open Access Journals (Sweden)

    Sean M Geary

    Full Text Available Standard cancer therapies, particularly those involving chemotherapy, are in need of modifications that both reduce short-term and long-term side effects as well as improve the overall survival of cancer patients. Here we show that combining low-dose chemotherapy with a therapeutic vaccination using an adenovirus encoding a model tumor-associated antigen, ovalbumin (Ad5-OVA, had a synergistic impact on survival in tumor-challenged mice. Mice that received the combinatorial treatment of Ad5-OVA plus low-dose 5-fluorouracil (5-FU had a 95% survival rate compared to 7% and 30% survival rates for Ad5-OVA alone and 5-FU alone respectively. The presence of 5-FU enhanced the levels of OVA-specific CD8(+ T lymphocytes in the spleens and draining lymph nodes of Ad5-OVA-treated mice, a phenomenon that was dependent on the mice having been tumor-challenged. Thus 5-FU may have enhanced survival of Ad5-OVA-treated mice by enhancing the tumor-specific immune response combined with eliminating tumor bulk. We also investigated the possibility that the observed therapeutic benefit may have been derived from the capacity of 5-FU to deplete MDSC populations. The findings presented here promote the concept of combining adenoviral cancer vaccines with low-dose chemotherapy.

  1. Cancer incidence rate after diagnostic X-ray exposure in 1976-2003 among patients of a university children's hospital

    International Nuclear Information System (INIS)

    Purpose: Although the carcinogenic effect of ionizing radiation is well known, knowledge gaps persist on the health effects of low-dose radiation, especially in children. The cancer incidence rate in a cohort of 92,957 children diagnosed using X-rays in the years 1976-2003 in the radiology department of a large university clinic was studied. Materials and Methods: Individual radiation doses per examination were reconstructed using an algorithm taking into account the dose area product and other exposure parameters together with conversion factors computed specifically for the equipment and protocols used in the radiology department. Incident cancer cases in the period 1980-2006 were identified via record linkage to the German Childhood Cancer Registry using pseudonymized data. Results: A total of 87 cancers occurred in the cohort between 1980 and 2006: 33 leukemia, 13 lymphoma, 10 brain tumors, and 31 other tumors. The standardized incidence ratio (SIR) for all cancers was 0.99 (95 % CI: 0.79 1.22). A dose-response relationship was not observed for all cancers, leukemia and lymphoma or solid tumors. The cancer risks for boys and girls did not differ. Conclusion: No increase in the cancer incidence risk in relation to very low doses of diagnostic ionizing radiation was observed in this study. However, the results are compatible with a broad range of risk estimates. (orig.)

  2. In vivo determination of very-low-density lipoprotein-apolipoprotein B100 secretion rates in humans with a low dose of L-[1-C-13]valine and isotope ratio mass spectrometry

    NARCIS (Netherlands)

    de Sain-van der Velden, MGM; Rabelink, TJ; Gadellaa, MM; Elzinga, H; Reijngoud, DJ; Kuipers, F; Stellaard, F

    1998-01-01

    The aim of the present study was to determine the rate of very-low-density lipoprotein (VLDL)-apolipoprotein (apo) B100 secretion in humans with a minimized amount of L-[1-C-13]valine infusion in combination with the use of gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) an

  3. 低剂量脾照射对局部晚期非小细胞肺癌放疗患者免疫系统的影响%The effects of low-dose splenic irradiation and radiotherapy on immune system of patients with locally advanced non-small cell lung cancer

    Institute of Scientific and Technical Information of China (English)

    Jun Liu; Hongsheng Yu; Qingjun Shang; Chao Yan; Peng Jiang; Xiang Wang

    2013-01-01

    Objective:The aim of the research was to study the effects of low-dose splenic irradiation and radiotherapy on immune system of patients with locally advanced non-small cell lung cancer (NSCLC). Methods:Twelve cases of stage III NSCLC in Tumor Radiotherapy Center of our hospital (the Affiliated Hospital of Medical College Qingdao University, China) were collected from July 2011 to July 2012; all patients were under 75 years old with clear pathology, measurable lesions and good personal statement. They were randomly divided into combined treatment group (D1 + D2) and control group (D1). The control group (D1) only received radiotherapy to the chest; combined treatment group (D1 + D2) received low-dose splenic irradiation plus conventional dose irradiation. Flow cytometry was used to detect the peripheral blood T lymphocyte immune indexes of patients before, during and after the treatment, classification by five blood cell analyzer was used to determine white blood cells, neutrophils, hemoglobin and platelet count. The radiation induced toxicity including esophagitis, pneumonia and gastrointestinal reaction was observed, as well as the dose when it happened. Results:There was no significant difference in the ratio between two groups in cells CD4+, CD8+ and CD4+/CD8+ after radiotherapy (P > 0.05). There was no change in these indicators in combined treatment group after treatment (P > 0.05), but it decreased in control group (P 0.05), but the patients in combined treatment group seemed to tolerate high dose well (P < 0.05). Conclusion:Low-dose splenic irradiation combined with radiotherapy to the chest can alleviate the injury degree of acute radiation induced the toxicity of locally advanced NSCLC patients, through affect the patient's immune function.

  4. Characteristics of changes in the number of yH2AX and Rad51 protein foci in human skin fibroblasts after prolonged exposure to low-dose rate X-ray radiation

    Directory of Open Access Journals (Sweden)

    Ozerov I.V.

    2014-12-01

    Full Text Available Aim: to compare the repair process of DNA double-strand breaks in mammalian cells after acute versus prolonged exposure to X-ray irradiation with different dose rates. Material and methods. Studies were performed on primary human fibroblasts isolated from skin biopsies of healthy volunteers (women, 29 and 30 years. Cells were irradiated using an X-ray machine RUB RUST-M1 (JSC "Ruselectronics", Moscow, Russia at 37°C temperature with a dose rate of 400 mGy/min (200 kV, 2*2.4 mA, a filter of 1.5mm AI or 4 mGy/min (50 kV, 2*0.4 mA, a filter of 1.5 mm AI. Immuno-cytochemical protein staining was utilized for yH2AX and Rad51 foci analysis. Results. Phosphorylated histone H2AX (yH2AX and the key protein of homologous recombination Rad51 foci formation and disappearance kinetics were investigated simultaneously in primary human dermal fibroblasts after acute and prolonged exposure to X-ray radiation at a same dose. It was shown that the relative yield of yH2AX foci per dose reduces with decrease in dose rate, while the relative yield of Rad51 foci conversely increases. Conclusion. Our findings suggest the fundamental differences in the ratio of non-homologous end joining and homologous recombination DNA repair in acute versus prolonged irradiated cells.

  5. Low doses of neutrons induce changes in gene expression

    International Nuclear Information System (INIS)

    Studies were designed to identify genes induced in fibroblasts after exposure to low-dose neutron radiation but not after γ rays. Our past work had shown similar modulation of transcripts for α-tubulin, β- and γ-actins, ornithine decarboxylase and interleukin 1 after exposure to either neutrons or γ rays. However, differences in the expression of β-protein kinase C and c-fos genes were observed, with both being induced after exposure to γ rays but not neutrons. Recently, we have identified two genes that are induced after exposure to neutrons but not γ rays: Rp-8 (a gene associated with apoptosis) and the long terminal repeat (LTR) of the human immunodeficiency virus (HIV). Induction of Rp-8 mRNA was demonstrated in Syrian hamster embryo (SHE) fibroblasts and was found to be induced in cells exposed to neutrons administered at low (0.005 Gy/min) and high dose rate (0.12 Gy/min). No induction of other genes associated with apoptosis such as Rp-2, bcl-2 and Tcl-30 was observed. The induction of transcription from the LTR of HIV was demonstrated in HeLa cells bearing a transfected construct of the chloramphenicol acetyl transferase (CAT) gene driven by the HIV-LTR promoter. Measurements of CAT activity and CAT transcripts after irradiation demonstrated an unresponsiveness to γ rays over a broad range of doses (0.1-3 Gy). Twofold induction of the HIV-LTR was detected after exposure to neutrons (0.48 Gy) administered at low (0.05 Gy/min) but not high (0.12 Gy/min) dose rates. Ultraviolet-mediated HIV-LTR induction, however, was inhibited by exposure to low-dose-rate neutron irradiation. These results are interesting in light of reports that Rp-8 is induced during apoptosis and that HIV causes apoptosis. 17 refs., 3 figs., 1 tab

  6. 多西他赛联合卡培他滨治疗复发转移乳腺癌的疗效及相关因素研究%Clinical study of low-dose docetaxel combined with capecitabine for metastatic breast cancer

    Institute of Scientific and Technical Information of China (English)

    陆海林; 李燕; 宁志强; 曹婷华; 陈超

    2011-01-01

    目的 探讨低剂量多西他赛联合卡培他滨治疗复发转移乳腺癌的疗效及其预测因素.方法 2006年6月至2009年12月收治38例复发转移乳腺癌女性患者给予多西他赛联合卡培他滨治疗,具体方案为:多西他赛60mg/m2静滴,d1;卡培他滨950mg/m2口服,每日2次,d1~d14;21天为1周期.2个周期评价疗效,并随访无进展生存时间(PFS).选取PS评分、绝经状态、ER、HER-2、转移数目、既往化疗共6个指标分别建立两分类Logistic回归模型和Cox风险比例模型,分析上述指标对疗效的预测情况.结果 38例患者均接受2~6个周期化疗,获CR 3例,PR 18例,SD 10例,PD 7例,有效率(RR)为55.3%(21/38);中位PFS为7.1个月(95%CI:4.8~9.6个月).主要毒副反应为恶心呕吐、乏力、白细胞减少和手足综合征等,其中3~4级白细胞减少为15.8%.6个指标中PS评分(P =0.003)、绝经状态(P =0.043)和转移数目(P =0.021)均与RR有关,仅PS评分为RR的独立预测因素(P <0.05);Cox风险比例模型显示,PS评分是PFS的独立预测因素(P<0.05).结论 低剂量多西他赛联合卡培他滨治疗复发转移乳腺癌的疗效好,安全性高;PS评分可以作为该方案疗效预测的独立因素.%Objective To evaluate the efficacy and its prognostic factors of low-dose docetaxel and capecitabine combination regimen( XT regimen) for patients with metastatic breast cancer. Methods Thirty-eight patients with metastatic breast cancer from June 2006 to December 2009 received XT regimen ( docetaxel 60mg/m2 iv, d1; capecitabine 950mg/m2 oral administrations twice a day, d1-d14; every 21 days was a cycle). The response rate(RR) was evaluated after 2 cycles and progress-free survival(PFS) was recorded. Performance status(PS), pausimenia status, ER, HER-2, number of transfer and chemotherapy history were enrolled to establish dichotomy logistic regression model and Cox proportion hazard model, respectively. Results All the 38 patients

  7. How to improve colon cancer screening rates

    Institute of Scientific and Technical Information of China (English)

    Luiz; Ronaldo; Alberti; Diego; Paim; Carvalho; Garcia; Debora; Lucciola; Coelho; David; Correa; Alves; De; Lima; Andy; Petroianu

    2015-01-01

    Colorectal carcinoma is a common cause of death throughout the world and may be prevented by routine control, which can detect precancerous neoplasms and early cancers before they undergo malignant transformation or metastasis. Three strategies may improve colon cancer screening rates: convince the population about the importance of undergoing a screening test; achieve higher efficacy in standard screening tests and make them more available to the community and develop new more sensitive and efficacious screening methods and make them available as routine tests. In this light, the present study seeks to review these three means through which to increase colon cancer screening rates.

  8. Health Effects of Exposure to Low Dose of Radiation

    International Nuclear Information System (INIS)

    Human beings are exposed to natural radiation from external sources include radionuclides in the earth and cosmic radiation, and by internal radiation from radionuclides, mainly uranium and thorium series, incorporated into the body. Living systems have adapted to the natural levels of radiation and radioactivity. But some industrial practices involving natural resources enhance these radionuclides to a degree that they may pose risk to humans and the environment if they are not controlled. Biological effects of ionizing radiation are the outcomes of physical and chemical processes that occur immediately after the exposure, then followed by biological process in the body. These processes will involve successive changes in the molecular, cellular, tissue and whole organism levels. Any dose of radiation, no matter how small, may produce health effects since even a single ionizing event can result in DNA damage. The damage to DNA in the nucleus is considered to be the main initiating event by which radiation causes damage to cells that results in the development of cancer and hereditary disease. It has also been indicated that cytogenetic damage can occur in cells that receive no direct radiation exposure, known as bystander effects. This paper reviews health risks of low dose radiation exposure to human body causing stochastic effects, i.e. cancer induction in somatic cells and hereditary disease in genetic cells. (author)

  9. Characterization of Staphylococcus aureus Strains Isolated from Czech Cystic Fibrosis Patients: High Rate of Ribosomal Mutation Conferring Resistance to MLS(B) Antibiotics as a Result of Long-Term and Low-Dose Azithromycin Treatment.

    Science.gov (United States)

    Tkadlec, Jan; Vařeková, Eva; Pantůček, Roman; Doškař, Jiří; Růžičková, Vladislava; Botka, Tibor; Fila, Libor; Melter, Oto

    2015-08-01

    Staphylococcus aureus is one of the most frequent pathogens infecting the respiratory tract of patients with cystic fibrosis (CF). This study was the first to examine S. aureus isolates from CF patients in the Czech Republic. Among 100 S. aureus isolates from 92 of 107 observed patients, we found a high prevalence of resistance to macrolide-lincosamide-streptogramin B (MLS(B)) antibiotics (56%). More than half of the resistant strains (29 of 56) carried a mutation in the MLS(B) target site. The emergence of MLS(B) resistance and mutations conferring resistance to MLS(B) antibiotics was associated with azithromycin treatment (p=0.000000184 and p=0.000681, respectively). Methicillin resistance was only detected in 3% of isolates and the rate of resistance to other antibiotics did not exceed 12%. The prevalence of small-colony variant (SCV) strains was relatively low (9%) and eight of nine isolates with the SCV phenotype were thymidine dependent. The study population of S. aureus was heterogeneous in structure and both the most prevalent community-associated and hospital-acquired clonal lineages were represented. Of the virulence genes, enterotoxin genes seg (n=52), sei (n=49), and sec (n=16) were the most frequently detected among the isolates. The PVL genes (lukS-PV and lukF-PV) have not been revealed in any of the isolates.

  10. MELODI - Multidisciplinary European Low dose Initiative - First Draft of Strategic Research Agenda (SRA)

    International Nuclear Information System (INIS)

    The SRA Working Group of MELODI (Multidisciplinary European Low Dose Initiative) was tasked to develop a long-term strategic research agenda (SRA) to guide the coherent integration of national low dose research programmes. Priorities that need to be addressed concern fundamental mechanistic research ranging from radiation track structure and the deposition of energy in biologically important molecules; the resultant homeostatic perturbations and the steps in the cellular and tissue metabolic pathways that eventually lead to disease pathologies. In fact, the main priorities are here the step-wise elucidation of the mechanisms of radiation-induced (oxidative) stress responses and their impact on radiation-induced cancers and non cancer diseases. To achieve this a holistic approach is proposed staring with radiation-specific effects, radiation-induced molecular, biological and pathological effects involving a systems biology approach as well as molecular epidemiology and mathematical modelling in order to come up with more solid low dose health risk assessments. The pathologies considered are outlined in the report where the need is stressed for the MELODI platform to involve a constellation of classical and emerging technologies in a highly multidisciplinary approach. Elucidating the shapes of low-dose response relationships and resolving the question of thresholds is paramount to resolving questions of risk for both populations and individuals. Much is known about radiation-induced cancer in humans and animal models but this needs to be pursued particularly at low doses. More recently, the scientific community has realised that low radiation-induced health effects range well beyond cancer. The priority non-cancer areas that need to be brought into focus are cardiovascular, neurological and ophthalmic. (A.C.)

  11. MELODI - Multidisciplinary European Low dose Initiative - First Draft of Strategic Research Agenda (SRA)

    Energy Technology Data Exchange (ETDEWEB)

    Averbeck, D. [IRSN, Fontenay-aux-Roses (France); Lloyd, D. [Health Protection Agency, Chilton (United Kingdom); O' Neill, P. [Gray Institute for Radiation Oncology and Biology, University of Oxford, Oxford (United Kingdom)

    2010-10-11

    The SRA Working Group of MELODI (Multidisciplinary European Low Dose Initiative) was tasked to develop a long-term strategic research agenda (SRA) to guide the coherent integration of national low dose research programmes. Priorities that need to be addressed concern fundamental mechanistic research ranging from radiation track structure and the deposition of energy in biologically important molecules; the resultant homeostatic perturbations and the steps in the cellular and tissue metabolic pathways that eventually lead to disease pathologies. In fact, the main priorities are here the step-wise elucidation of the mechanisms of radiation-induced (oxidative) stress responses and their impact on radiation-induced cancers and non cancer diseases. To achieve this a holistic approach is proposed staring with radiation-specific effects, radiation-induced molecular, biological and pathological effects involving a systems biology approach as well as molecular epidemiology and mathematical modelling in order to come up with more solid low dose health risk assessments. The pathologies considered are outlined in the report where the need is stressed for the MELODI platform to involve a constellation of classical and emerging technologies in a highly multidisciplinary approach. Elucidating the shapes of low-dose response relationships and resolving the question of thresholds is paramount to resolving questions of risk for both populations and individuals. Much is known about radiation-induced cancer in humans and animal models but this needs to be pursued particularly at low doses. More recently, the scientific community has realised that low radiation-induced health effects range well beyond cancer. The priority non-cancer areas that need to be brought into focus are cardiovascular, neurological and ophthalmic. (A.C.)

  12. New approach for food allergy management using low-dose oral food challenges and low-dose oral immunotherapies

    Directory of Open Access Journals (Sweden)

    Noriyuki Yanagida

    2016-04-01

    With food allergies, removing the need to eliminate a food that could be consumed in low doses could significantly improve quality of life. This review discusses the importance of an OFC and OIT that use low doses of causative foods as the target volumes. Utilizing an OFC or OIT with a low dose as the target volume could be a novel approach for accelerating the tolerance to causative foods.

  13. What can be learned from epidemiologic studies of persons exposed to low doses of radiation?

    International Nuclear Information System (INIS)

    The main objective of radiation risk assessment is to determine the risk of various adverse health effects associated with exposure to low doses and low dose rates. Extrapolation of risks from studies of persons exposed at high doses (generally exceeding 1 Sv) and dose rates has been the primary approach used to achieve this objective. The study of Japanese atomic bomb survivors in Hiroshima and Nagasaki has played an especially important role in risk assessment efforts. A direct assessment of the dose-response function based on studies of persons exposed at low doses and dose rates is obviously desirable. This paper focuses on the potential of both current and future nuclear workers studies for investigating the dose-response functions at low doses, and also discusses analyses making use of the low dose portion of the atomic bomb survivor data. Difficulties in using these data are the statistical imprecision of estimated dose-response parameters, and potential bias resulting from confounding factors and from uncertainties in dose estimates

  14. Low dose radiation and plant growth

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Jae; Lee, Hae Youn; Park, Hong Sook

    2001-03-01

    Ionizing radiation includes cosmic radiation, earth radiation, radionuclides for the medical purpose and nuclear industry, fallout radiation. From the experimental results of various radiation effects on seeds or seedlings, it was found that germination rate, development, respiration rate, reproduction and blooming were accelerated compared with the control. In mammal, hormesis phenomenon manifested itself in increased disease resistance, lifespan, and decreased rate of tumor incidence. In plants, it was shown that germination, sprouting, growth, development, blooming and resistance to disease were accelerated.

  15. Low dose radiation and plant growth

    International Nuclear Information System (INIS)

    Ionizing radiation includes cosmic radiation, earth radiation, radionuclides for the medical purpose and nuclear industry, fallout radiation. From the experimental results of various radiation effects on seeds or seedlings, it was found that germination rate, development, respiration rate, reproduction and blooming were accelerated compared with the control. In mammal, hormesis phenomenon manifested itself in increased disease resistance, lifespan, and decreased rate of tumor incidence. In plants, it was shown that germination, sprouting, growth, development, blooming and resistance to disease were accelerated

  16. Bayesian approach in MN low dose of radiation counting

    International Nuclear Information System (INIS)

    The Micronucleus assay in lymphocytes is a well established technique for the assessment of genetic damage induced by ionizing radiation. Due to the presence of a natural background of MN the net MN is obtained by subtracting this value to the gross value. When very low doses of radiation are given the induced MN is close even lower than the predetermined background value. Furthermore, the damage distribution induced by the radiation follows a Poisson probability distribution. These two facts pose a difficult task to obtain the net counting rate in the exposed situations. It is possible to overcome this problem using a bayesian approach, in which the selection of a priori distributions for the background and net counting rate plays an important role. In the present work we make a detailed analysed using bayesian theory to infer the net counting rate in two different situations: a) when the background is known for an individual sample, using exact value value for the background and Jeffreys prior for the net counting rate, and b) when the background is not known and we make use of a population background distribution as background prior function and constant prior for the net counting rate. (Author)

  17. Lung cancer death rates fall, helping drive decrease in overall cancer death rates

    Science.gov (United States)

    The Annual Report to the Nation on the Status of Cancer, covering the period 1975–2010, showed death rates for lung cancer, which accounts for more than one in four cancer deaths, dropping at a faster pace than in previous years.

  18. BCC and Childhood Low Dose Radiation

    Directory of Open Access Journals (Sweden)

    Arash Beiraghi Toosi

    2014-10-01

    Full Text Available Skin cancer is a late complication of ionizing radiation. Two skin neoplasms prominent Basal Cell Carcinoma (BCC and Squamous Cell Carcinoma (SCC are the most famous complications of radiotherapy. Basal Cell Carcinoma (BCC is the most common human malignant neoplasm. Many genetic and environmental factors are involved in its onset. BCC is observed in sun-exposed areas of skin. Some patients with scalp BCC have had a history of scalp radiation for the treatment of tinea capitis in childhood. Evidence that ionizing radiation is carcinogenic first came from past reports of nonmelanoma skin cancers on the hands of workers using radiation devices. The total dose of radiation and irradiated site exposed to sunlight can lead to a short incubation period. It is not clear whether BCC in these cases has a more aggressive nature and requires a more aggressive resection of the lesion. The aim of this review was to evaluate the differences between BCC specification and treatment results between irradiated and nonirradiated patients.

  19. PREOPERATIVE THERAPY OF LOW-DOSE ASPIRIN IN INTERNAL MAMMARY ARTERY BYPASS OPERATIONS WITH AND WITHOUT LOW-DOSE APROTININ

    NARCIS (Netherlands)

    SCHONBERGER, JPAM; BREDEE, JJ; VANOEVEREN, W; VANZUNDERT, AAJ; VERKROOST, M; TERWOORST, J; BAVINCK, JH; BERREKLOUW, E; WILDEVUUR, CRH

    1993-01-01

    The effect of preoperative low-dose aspirin (1 mg/kg of body weight) and intraoperative low-dose aprotinin (2 million kallikrein inactivator units) treatment on perioperative blood loss and blood requirements in patients who undergo internal mammary artery bypass operations is unknown. Therefore, we

  20. MiR-34a is up-regulated in response to low dose, low energy X-ray induced DNA damage in breast cells

    International Nuclear Information System (INIS)

    MicroRNAs are non-coding RNAs involved in the regulation of gene expression including DNA damage responses. Low doses of low energy X-ray radiation, similar to those used in mammographic exams, has been described to be genotoxic. In the present work we investigated the expression of miR-34a; a well described p53-regulated miRNA implicated in cell responses to X-ray irradiation at low doses. Non-cancerous breast cell line MCF-10A and cancerous T-47D and MCF-7 cell lines were submitted to a low-energy X-ray irradiation (ranging from 28–30 Kv) using a dose of 5 Gy. The expression level of miR-34a, let-7a and miR-21 was assessed by qRT-PCR at 4 and 24 hours post-irradiation. DNA damage was then measured by comet assay and micronuclei estimation in MCF-10A and MCF-7 cell lines, where an increase of miR-34a levels could be observed after irradiation. The rate of apoptotic cells was estimated by nuclear staining and fluorescence microscopy. These experiments were also performed at low doses (3; 12 and 48 mGy) in MCF-10A and MCF-7 cell lines. We have observed an increase in miR-34a expression 4 hours post-irradiation at 5 Gy in MCF-10A and MCF-7 cell lines while its level did not change in T-47D, a breast cancer cell line bearing non-functional p53. At low doses, miR-34a was up-regulated in non-tumoral MCF-10A to a higher extent as compared to MCF-7. MiR-34a levels decreased 24 hours post-irradiation. We have also observed DNA damage and apoptosis at low-energy X-ray irradiation at low doses and the high dose in MCF-10A and MCF-7 4 and 24 hours post-irradiation relative to the mock control. Low energy X-ray is able to promote DNA strand breaks and miR-34a might be involved in cell responses to low energy X-ray DNA damage. MiR-34a expression correlates with X-ray dose, time after irradiation and cell type. The present study reinforces the need of investigating consequences of low dose X-ray irradiation of breast cells

  1. Effect of ultra-low-dose estriol and lactobacilli vaginal tablets (Gynoflor®) on inflammatory and infectious markers of the vaginal ecosystem in postmenopausal women with breast cancer on aromatase inhibitors.

    Science.gov (United States)

    Donders, G; Bellen, G; Neven, P; Grob, P; Prasauskas, V; Buchholz, S; Ortmann, O

    2015-10-01

    This study was a detailed microscopic analysis of the changes of vaginal microflora characteristics after application of 0.03 mg estriol-lactobacilli combination on the vaginal ecosystem in postmenopausal breast cancer (BC) survivors on aromatase inhibitors (AI) with severe atrophic vaginitis. A total of 16 BC women on AI applied daily one vaginal tablet of Gynoflor® for 28 days followed by a maintenance therapy of three tablets weekly for 8 weeks. During four follow up visits a smear from the upper lateral vaginal wall was analysed by phase contrast microscopy at 400 times magnification in order to classify the lactobacillary grades(LBG), bacterial vaginosis (BV), aerobic vaginitis (AV), vulvovaginal candidosis (VVC), proportional number of leukocytes and evidence of parabasal cells and epitheliolysis. LBG improved from 81% LBG-III at entry to 88% LBG-I&IIa after 2 weeks of initial therapy, which further improved upon follow up (p lactobacilli results in rapid and enduring improvement of all markers of the vaginal microflora and epithelial vaginal cell quality in women with breast cancer on AI with dyspareunia. Candida may develop soon after its use, but rapidly disappears again upon their prolonged use. Due to its excellent safety profiles and clinical efficacy we recommend this product as first choice in women on AI with severe dyspareunia.

  2. Ultra low-dose CT attenuation correction in PET SPM

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shyh-Jen; Yang, Bang-Hung [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, 155 Li-Nong Street, Sec. 2, Taipei 112, Taiwan (China); Department of Nuclear Medicine, Taipei Veterans General Hospital, Taiwan (China); Tsai, Chia-Jung [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, 155 Li-Nong Street, Sec. 2, Taipei 112, Taiwan (China); Yang, Ching-Ching [Department of Radiological Technology, Tzu Chi College of Technology, Hualien, Taiwan (China); Lee, Jason J.S. [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, 155 Li-Nong Street, Sec. 2, Taipei 112, Taiwan (China); Wu, Tung-Hsin, E-mail: tung@ym.edu.t [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, 155 Li-Nong Street, Sec. 2, Taipei 112, Taiwan (China)

    2010-07-21

    The use of CT images for attenuation correction (CTAC) allows significantly shorter scanning time and a high quality noise-free attenuation map compared with conventional germanium-68 transmission scan because at least 10{sup 4} times greater of photon flux would be generated from a CT scan under standard operating condition. However, this CTAC technique would potentially introduce more radiation risk to the patients owing to the higher radiation exposure from CT scan. Statistic parameters mapping (SPM) is a prominent technique in nuclear medicine community for the analysis of brain imaging data. The purpose of this study is to assess the feasibility of low-dose CT (LDCT) and ultra low-dose CT (UDCT) in PET SPM applications. The study was divided into two parts. The first part was to evaluate of tracer uptake distribution pattern and quantity analysis by using the striatal phantom to initially assess the feasibility of AC for clinical purpose. The second part was to examine the group SPM analysis using the Hoffman brain phantom. The phantom study is to simulate the human brain and to reduce the experimental uncertainty of real subjects. The initial studies show that the results of PET SPM analysis have no significant differences between LDCT and UDCT comparing to the current used default CTAC. Moreover, the dose of the LDCT is lower than that of the default CT by a factor of 9, and UDCT can even yield a 42 times dose reduction. We have demonstrated the SPM results while using LDCT and UDCT for PET AC is comparable to those using default CT setting, suggesting their feasibility in PET SPM applications. In addition, the necessity of UDCT in PET SPM studies to avoid excess radiation dose is also evident since most of the subjects involved are non-cancer patients or children and some normal subjects are even served as a comparison group in the experiment. It is our belief that additional attempts to decrease the radiation dose would be valuable, especially for children

  3. Low-dose CT denoising with convolutional neural network

    CERN Document Server

    Chen, Hu; Zhang, Weihua; Liao, Peixi; Li, Ke; Zhou, Jiliu; Wang, Ge

    2016-01-01

    To reduce the potential radiation risk, low-dose CT has attracted much attention. However, simply lowering the radiation dose will lead to significant deterioration of the image quality. In this paper, we propose a noise reduction method for low-dose CT via deep neural network without accessing original projection data. A deep convolutional neural network is trained to transform low-dose CT images towards normal-dose CT images, patch by patch. Visual and quantitative evaluation demonstrates a competing performance of the proposed method.

  4. Low-Dose CT via Deep Neural Network

    CERN Document Server

    Chen, Hu; Zhang, Weihua; Liao, Peixi; Li, Ke; Zhou, Jiliu; Wang, Ge

    2016-01-01

    In order to reduce the potential radiation risk, low-dose CT has attracted more and more attention. However, simply lowering the radiation dose will significantly degrade the imaging quality. In this paper, we propose a noise reduction method for low-dose CT via deep learning without accessing the original projection data. An architecture of deep convolutional neural network was considered to map the low-dose CT images into its corresponding normal-dose CT images patch by patch. Qualitative and quantitative evaluations demonstrate a state-the-art performance of the proposed method.

  5. Hippocampal volumes in patients exposed to low-dose radiation to the basal brain. A case–control study in long-term survivors from cancer in the head and neck region

    International Nuclear Information System (INIS)

    An earlier study from our group of long time survivors of head and neck cancer who had received a low radiation dose to the hypothalamic-pituitary region, with no signs of recurrence or pituitary dysfunction, had their quality of life (QoL) compromised as compared with matched healthy controls. Hippocampal changes have been shown to accompany several psychiatric conditions and the aim of the present study was to test whether the patients’ lowered QoL was coupled to a reduction in hippocampal volume. Patients (11 men and 4 women, age 31–65) treated for head and neck cancer 4–10 years earlier and with no sign of recurrence or pituitary dysfunction, and 15 matched controls were included. The estimated radiation doses to the basal brain including the hippocampus (1.5 – 9.3 Gy) had been calculated in the earlier study. The hippocampal volumetry was done on coronal sections from a 1.5 T MRI scanner. Measurements were done by two independent raters, blinded to patients and controls, using a custom method for computer assisted manual segmentation. The volumes were normalized for intracranial volume which was also measured manually. The paired t test and Wilcoxon’s signed rank test were used for the main statistical analysis. There was no significant difference with respect to left, right or total hippocampal volume between patients and controls. All mean differences were close to zero, and the two-tailed 95% confidence interval for the difference in total, normalized volume does not include a larger than 8% deficit in the patients. The study gives solid evidence against the hypothesis that the patients’ lowered quality of life was due to a major reduction of hippocampal volume

  6. Synergistic effect of exemestane and low-dose methotrexate on exemestane-resistant MCF-7 human breast cancer cells and reversal mechanism of drug-resistance%依西美坦与低剂量甲氨蝶呤对依西美坦耐药人乳腺癌细胞的协同效应及逆转耐药机制

    Institute of Scientific and Technical Information of China (English)

    居伶俐; 袁媛; 潘跃银

    2014-01-01

    Objective To investigate the combined effect of exemestane and low-dose methotrexate on exemestane-resistant MCF-7 human breast cancer cells( MCF-7/EXE). Methods Antiproliferative effects of exemestane and low-dose of methotrexate, alone and in combination on growth of MCF-7/EXE cells were assessed by using the MTT assay. Synergistic interaction between the two drugs was evaluated in vitro by using the combination index ( CI) method. The cell cycle distribution was analyzed by flow cytometry in a half inhibitory concentration of exemestane and low-dose of methotrexate . The changes of apoptosis on MCF-7/EXE cells exposed to two drugs alone or in com-bination were observed by fluorescence microscope. The expression of Bcl-2,AKT,P-AKT and cyclooxygenase-2 was investigated by Western blot. Results MTT assays indicated that the combination treatment apparently decreased the viability of MCF-7/EXE cells compared to single drug treatment (CI<0. 9). In addition, the combination of exemestane and low-dose methotrexate exhibited a synergistic inhibition of cell proliferation, arrested the cell cycle in the S phase significantly and produced a stronger inhibitory effects on P-AKT, Bcl-2 and cyclooxygenase-2 ex-pression than control or individual drug treatment. Conclusion The combination of the two inhibitors significantly increases the response as compared to single agent treatment, suggesting that combination treatment which can re-verse the resistance of exemestane could be a more effective approach to breast cancer.%目的研究依西美坦( EXE )与低剂量甲氨蝶呤( MTX)对依西美坦耐药人乳腺癌 MCF-7细胞( MCF-7/EXE)的增殖抑制作用及意义。方法使用 MTT 法检测EXE与低剂量MTX单药和联合给药对MCF-7/EXE细胞的增殖抑制作用,计算依西美坦与低剂量甲氨蝶呤联合给药时的联合指数(CI),评价两药间的相互作用。流式细胞术检测IC50浓度药物EXE组(120μmol/L)、低剂量MTX组(60 nmol

  7. Effects of low doses of ionizing radiation; Effets des faibles doses de rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    Masse, R. [Office de Protection contre les Rayonnements Ionisants, 78 - le Vesinet (France)

    2006-07-01

    Several groups of human have been irradiated by accidental or medical exposure, if no gene defect has been associated to these exposures, some radioinduced cancers interesting several organs are observed among persons exposed over 100 to 200 mSv delivered at high dose rate. Numerous steps are now identified between the initial energy deposit in tissue and the aberrations of cell that lead to tumors but the sequence of events and the specific character of some of them are the subject of controversy. The stake of this controversy is the risk assessment. From the hypothesis called linear relationship without threshold is developed an approach that leads to predict cancers at any tiny dose without real scientific foundation. The nature and the intensity of biological effects depend on the quantity of energy absorbed in tissue and the modality of its distribution in space and time. The probability to reach a target (a gene) associated to the cancerating of tissue is directly proportional to the dose without any other threshold than the quantity of energy necessary to the effect, its probability of effect can be a more complex function and depends on the quality of the damage produced as well as the ability of the cell to repair the damage. These two parameters are influenced by the concentration of initial injuries in the target so by the quality of radiation and by the dose rate. The mechanisms of defence explain the low efficiency of radiation as carcinogen and then the linearity of effects in the area of low doses is certainly the least defensible scientific hypothesis for the prediction of the risks. (N.C.)

  8. Long term/low dose formalin exposure to small-scale recirculation aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg; Nielsen, Jeppe L.;

    2010-01-01

    Repetitive long term formalin application at low dose was investigated to determine the effect on formaldehyde removal rate, biofilter nitrification and the microbial composition in small-scale recirculation aquaculture biofilters. Six pilot-scale recirculation aquaculture systems holding rainbow...... Nitrobacter sp. was not detected. The relative abundances of AOB and NOB in the untreated system were generally higher compared to the system exposed to formalin. Low dose formalin in recirculated aquaculture systems proved to be a possible treatment strategy, as the effect on nitrification was minimal. Since...

  9. Low doses effects of ionizing radiation on Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    The exposure of living cells to low doses of ionizing radiation induce in response the activation of cellular protection mechanisms against subsequent larger doses of radiation. This cellular adaptive response may vary depending on radiation intensity and time of exposure, and also on the testing probes used whether they were mammalian cells, yeast, bacteria and other organisms or cell types. The mechanisms involved are the genome activation, followed by DNA repair enzymes synthesis. Due to the prompt cell response, the cell cycle can be delayed, and the secondary detoxification of free radicals and/or activation of membrane bound receptors may proceed. All these phenomena are submitted to intense scientific research nowadays, and their elucidation will depend on the complexity of the organism under study. In the present work, the effects of low doses of ionizing radiation (gamma rays) over a suspension of the yeast Saccharomyces cerevisiae (Baker's yeast) was studied, mainly in respect to survival rate and radio-adaptive response. At first, the yeast surviving curve was assessed towards increasing doses, and an estimation of Lethal Dose 50 (LD50) was made. The irradiation tests were performed at LINAC (electrons Linear Accelerator) where electron energy reached approximately 2.65 MeV, and gamma-radiation was produced for bremsstrahlung process over an aluminium screen target. A series of experiments of conditioning doses was performed and an increment surviving fraction was observed when the dose was 2.3 Gy and a interval time between this and a higher dose (challenging dose) of 27 Gy was 90 minutes. A value of 58 ± 4 Gy was estimated for LD50, at a dose rate of 0.44 ± 0.03 Gy/min These quantities must be optimized. Besides data obtained over yeast survival, an unusual increasing amount of tiny yeast colonies appeared on the agar plates after incubation, and this number increased as increasing the time exposure. Preliminary results indicate these colonies as

  10. Bronchiolitis obliterans organizing pneumonia during low-dose amiodarone therapy

    NARCIS (Netherlands)

    Jessurun, GAJ; Hoogenberg, K; Crijns, HJGM

    1997-01-01

    Two cases of amiodarone-induced pulmonary toxicity during a relatively short period of low-dose amiodarone treatment are reported. The toxicity risk of amiodarone is determined by cumulative factors in individual patients.

  11. Topics on study of low dose-effect relationship

    International Nuclear Information System (INIS)

    It is not exceptional but usually observed that a dose-effect relationship in biosystem is not linear. Sometimes, the low dose-effect relationship appears entirely contrary to the expectation from high dose-effect. This is called a 'hormesis' phenomena. A high dose irradiation inflicts certainly an injury on biosystem. No matter how low the dose may be, an irradiation might inflict some injury on biosystem according to Linear Non-Threshold hypothesis(LNT). On the contrary to the expectation, a low dose irradiation stimulates immune system, and promotes cell proliferation. This is called 'radiation hormesis'. The studies of the radiation hormesis are made on from four points of view as follows: (1) radiation adaptive response, (2) revitalization caused by a low dose stimulation, (3) a low dose response unexpected from the LNT hypothesis, (4) negation of the LNT hypothesis. The various empirical proofs of radiation hormesis are introduced in the report. (M . Suetake)

  12. Development of Plant Application Technique of Low Dose Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Byung Yeoup; Kim, Jae Sung; Lim, Yong Taek (and others)

    2007-07-15

    The project was carried out to achieve three aims. First, development of application techniques of cell-stimulating effects by low-dose radiation. Following irradiation with gamma-rays of low doses, beneficial effects in crop germination, early growth, and yield were investigated using various plant species and experimental approaches. For the actual field application, corroborative studies were also carried out with a few concerned experimental stations and farmers. Moreover, we attempted to establish a new technique of cell cultivation for industrial mass-production of shikonin, a medicinal compound from Lithospermum erythrorhizon and thereby suggested new application fields for application techniques of low-dose radiation. Second, elucidation of action mechanisms of ionizing radiation in plants. By investigating changes in plant photosynthesis and physiological metabolism, we attempted to elucidate physiological activity-stimulating effects of low-dose radiation and to search for radiation-adaptive cellular components. Besides, analyses of biochemical and molecular biological mechanisms for stimulus-stimulating effects of low-dose radiation were accomplished by examining genes and proteins inducible by low-dose radiation. Third, development of functional crop plants using radiation-resistant factors. Changes in stress-tolerance of plants against environmental stress factors such as light, temperature, salinity and UV-B stress after exposed to low-dose gamma-rays were investigated. Concerned reactive oxygen species, antioxidative enzymes, and antioxidants were also analyzed to develop high value-added and environment-friendly functional plants using radiation-resistant factors. These researches are important to elucidate biological activities increased by low-dose radiation and help to provide leading technologies for improvement of domestic productivity in agriculture and development of high value-added genetic resources.

  13. Alteration of cytokine profiles in mice exposed to chronic low-dose ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Suk Chul [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of); Lee, Kyung-Mi [Global Research Lab, BAERI Institute, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul 136-705 (Korea, Republic of); Kang, Yu Mi [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of); Kim, Kwanghee [Global Research Lab, BAERI Institute, Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul 136-705 (Korea, Republic of); Kim, Cha Soon; Yang, Kwang Hee; Jin, Young-Woo [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of); Kim, Chong Soon [Department of Nuclear Medicine, Haeundae Paik Hospital, Inje University, Busan 612-030 (Korea, Republic of); Kim, Hee Sun, E-mail: hskimdvm@khnp.co.kr [Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., 388-1, Ssangmun-dong, Dobong-gu, Seoul 132-703 (Korea, Republic of)

    2010-07-09

    While a high-dose of ionizing radiation is generally harmful and causes damage to living organisms, a low-dose of radiation has been shown to be beneficial in a variety of animal models. To understand the basis for the effect of low-dose radiation in vivo, we examined the cellular and immunological changes evoked in mice exposed to low-dose radiation at very low (0.7 mGy/h) and low (3.95 mGy/h) dose rate for the total dose of 0.2 and 2 Gy, respectively. Mice exposed to low-dose radiation, either at very low- or low-dose rate, demonstrated normal range of body weight and complete blood counts. Likewise, the number and percentage of peripheral lymphocyte populations, CD4{sup +} T, CD8{sup +} T, B, or NK cells, stayed unchanged following irradiation. Nonetheless, the sera from these mice exhibited elevated levels of IL-3, IL-4, leptin, MCP-1, MCP-5, MIP-1{alpha}, thrombopoietin, and VEGF along with slight reduction of IL-12p70, IL-13, IL-17, and IFN-{gamma}. This pattern of cytokine release suggests the stimulation of innate immunity facilitating myeloid differentiation and activation while suppressing pro-inflammatory responses and promoting differentiation of naive T cells into T-helper 2, not T-helper 1, types. Collectively, our data highlight the subtle changes of cytokine milieu by chronic low-dose {gamma}-radiation, which may be associated with the functional benefits observed in various experimental models.

  14. Alteration of cytokine profiles in mice exposed to chronic low-dose ionizing radiation

    International Nuclear Information System (INIS)

    While a high-dose of ionizing radiation is generally harmful and causes damage to living organisms, a low-dose of radiation has been shown to be beneficial in a variety of animal models. To understand the basis for the effect of low-dose radiation in vivo, we examined the cellular and immunological changes evoked in mice exposed to low-dose radiation at very low (0.7 mGy/h) and low (3.95 mGy/h) dose rate for the total dose of 0.2 and 2 Gy, respectively. Mice exposed to low-dose radiation, either at very low- or low-dose rate, demonstrated normal range of body weight and complete blood counts. Likewise, the number and percentage of peripheral lymphocyte populations, CD4+ T, CD8+ T, B, or NK cells, stayed unchanged following irradiation. Nonetheless, the sera from these mice exhibited elevated levels of IL-3, IL-4, leptin, MCP-1, MCP-5, MIP-1α, thrombopoietin, and VEGF along with slight reduction of IL-12p70, IL-13, IL-17, and IFN-γ. This pattern of cytokine release suggests the stimulation of innate immunity facilitating myeloid differentiation and activation while suppressing pro-inflammatory responses and promoting differentiation of naive T cells into T-helper 2, not T-helper 1, types. Collectively, our data highlight the subtle changes of cytokine milieu by chronic low-dose γ-radiation, which may be associated with the functional benefits observed in various experimental models.

  15. Low-Dose Radiation Exposure and Atherosclerosis in ApoE(-/-) Mice

    NARCIS (Netherlands)

    Mitchel, R. E. J.; Hasu, M.; Bugden, M.; Wyatt, H.; Little, M. P.; Gola, A.; Hildebrandt, G.; Priest, N. D.; Whitman, S. C.

    2011-01-01

    The hypothesis that single low-dose exposures (0.025-0.5 Gy) to low-LET radiation given at either high (about 150 mGy/min) or low (1 mGy/min) dose rate would promote aortic atherosclerosis was tested in female C57BL/6J mice genetically predisposed to this disease (ApoE(-/-)). Mice were exposed eithe

  16. Effect of low-dose gamma-radiation upon hatchability and weight of chickens

    Energy Technology Data Exchange (ETDEWEB)

    Vilic, M.; Kraljevic, P.; Simpraga, M. [Zagreb Univ., Veterinary faculty (Croatia); Miljanic, S. [Ruder Boskovic Institute, Zagreb (Croatia)

    2006-07-01

    Full text of publication follows: Although any dose of ionizing radiation has generally been recognized to be detrimental to living being, low dose ionizing radiation seems to invoke primary stimulative effects. Stimulatory effects of low dose ionizing radiation include many aspects such as growth, fecundity and longevity stimulation, accelerated development, enhance biological responses for immune systems, enzymatic repair, physiological functions, and the removal of cellular damage, including prevention and removal of cancers and other diseases. Low dose ionizing radiation might also cause changes in the concentration of some biochemical parameters in blood plasma of chickens such as changes in the concentration of total proteins, glucose and cholesterol. The objective of this study was to determine the effect of low doses of gamma irradiation before incubation and on the seventh day of incubation on hatchability of eggs and body weight of chickens. This study includes three independent experiments. In the first experiment, six-hundred eggs produced by a commercial flock of Avian-line 34, were irradiated by a dose of 0.15 Gy gamma radiation (60 Co) before incubation. In the second experiments also involving six-hundred-line 34 eggs were irradiated by dose of 0.15 Gy gamma radiation on the seventh day of incubation. In the third experiment three-hundred eggs produced by a commercial flock of Ross 308 were irradiated by dose 0.30 Gy gamma irradiation before incubation. Along with the chickens which were hatched from irradiated eggs, there was a control group of chickens hatched from nonirradiated eggs. All other conditions were the same for both groups. Hatchability was calculated in terms of all eggs divided with fertile eggs which hatched. The individual weights of the chickens were determined on the first and on the forty second day. Growth data were analyzed statistically by t-test. Irradiation of chicken eggs and embryos at rates o f 0.15 Gy increases

  17. Performance of computer-aided detection of pulmonary nodules in low-dose CT : comparison with double reading by nodule volume

    NARCIS (Netherlands)

    Zhao, Y.; de Bock, G.H.; Vliegenthart, R.; van Klaveren, R.J.; Wang, Y.; Bogoni, L.; de Jong, P.A.; Mali, W.P.; Ooijen, P.M.A.; Oudkerk, M.

    2012-01-01

    To evaluate performance of computer-aided detection (CAD) beyond double reading for pulmonary nodules on low-dose computed tomography (CT) by nodule volume. A total of 400 low-dose chest CT examinations were randomly selected from the NELSON lung cancer screening trial. CTs were evaluated by two ind

  18. Current status of high dose rate brachytherapy in cervical cancer in Korea and optimal treatment schedule

    Energy Technology Data Exchange (ETDEWEB)

    Huh, Seung Jae [College of Medicine, Sungkyunkwan Univ., Seoul (Korea, Republic of)

    1998-12-01

    Brachytherapy is an essential part of radiotherapy for uterine cervical cancer. The low dose rate (LDR) regimen has been the major technique of intracavitary therapy for cervical cancer. However, there has been an expansion in the last 20 years of high dose rate (HDR) machines using Ir-192 sources. Since 1979, HDR brachytherapy has been used for the treatment of uterine cervical cancer in Korea. The number of institutions employing HDR has been increasing, while the number of low dose rate system has been constant. In 1995, there was a total 27 HDR brachytherapy units installed and 1258 cases of patients with cervical cancer were treated with HDR. Most common regimens of HDR brachytherapy are total dose of 30-39 Gy at point A with 10-13 fractions in three fractions per week, 24-32 Gy with 6-8 fractions in two fractions per week, and 30-35 Gy with 6-7 fractions in two fractions per week. The average fractionation regimen of HDR brachytherapy is about 8 fractions of 4. 1 Gy each to point A. In Korea, treatment results for HDR brachytherapy are comparable with the LDR series and appears to be a safe and effective alternative to LDR therapy for the treatment of cervical carcinoma. Studies from the major centers report the five-year survival rate of cervical cancer as, 78-86% for Stage I, 68-85% for stage II, and 38-56% for Stage III. World-wide questionnaire study and Japanese questionnaire survey of multiple institutions showed no survival difference in any stages and dose-rate effect ratio (HDR/LDR) was calculated to be 0.54 to 0.58. However, the optimum treatment doses and fractionation schemes appropriate to generate clinical results comparable to conventional LDR schemes have yet to be standardized. In conclusion, HDR intracavitary radiotherapy is increasingly practiced in Korea and an effective treatment modality for cervical cancer. To determine the optimum radiotherapy dose and fractionation schedule, a nation-wide prospective study is necessary in Korea. In

  19. Effects of acute low doses of gamma-radiation on erythrocytes membrane.

    Science.gov (United States)

    Mahmoud, Sherif S; El-Sakhawy, Eman; Abdel-Fatah, Eman S; Kelany, Adel M; Rizk, Rizk M

    2011-03-01

    It is believed that any dose of ionizing radiation may damage cells and that the mutated cells could develop into cancer cells. Additionally, results of research performed over the past century on the effects of low doses of ionizing radiation on biological organisms show beneficial health effects, called hormesis. Much less is known about the cellular response to low doses of ionizing radiation, such as those typical for medical diagnostic procedures, normal occupational exposures or cosmic-ray exposures at flight altitudes. Extrapolating from the effects observed at higher doses to predict changes in cells after low-dose exposure is problematic. We examined the biological effects of low doses (0.01-0.3 Gy) of γ-radiation on the membrane characteristics of erythrocytes of albino rats and carried out osmotic fragility tests and Fourier transform infrared spectroscopy (FTIR). Our results indicate that the lowest three doses in the investigated radiation range, i.e., 0.01, 0.025 and 0.05 Gy, resulted in positive effects on the erythrocyte membranes, while a dose of 0.1 Gy appeared to represent the limiting threshold dose of those positive effects. Doses higher than 0.1 Gy were associated with the denaturation of erythrocyte proteins. PMID:20865271

  20. Imputability of health effects to low-dose radiation exposure situations

    International Nuclear Information System (INIS)

    The key note address is aimed to discuss a crucial issue in nuclear law: whether or not late health effects of stochastic nature, such as radio-induced cancer or hereditable effects, are attributable to radiation exposure situations delivering relatively low radiation doses and, therefore, whether such effects are imputable to those responsible of such situations. The term low dose is used in the presentation when referring to doses similar to natural background doses. (author)

  1. Biological effects of low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Few weeks ago, when the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) submitted to the U.N. General Assembly the UNSCEAR 1994 report, the international community had at its disposal a broad view of the biological effects of low doses of ionizing radiation. The 1994 report (272 pages) specifically addressed the epidemiological studies of radiation carcinogenesis and the adaptive responses to radiation in cells and organisms. The report was aimed to supplement the UNSCEAR 1993 report to the U.N. General Assembly- an extensive document of 928 pages-which addressed the global levels of radiation exposing the world population, as well as some issues on the effects of ionizing radiation, including: mechanisms of radiation oncogenesis due to radiation exposure, influence of the level of dose and dose rate on stochastic effects of radiation, hereditary effects of radiation effects on the developing human brain, and the late deterministic effects in children. Those two UNSCEAR reports taken together provide an impressive overview of current knowledge on the biological effects of ionizing radiation. This article summarizes the essential issues of both reports, although it cannot cover all available information. (Author)

  2. Low-Dose Radiation Therapy (2 Gy × 2) in the Treatment of Orbital Lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Fasola, Carolina E. [Department of Radiation Oncology, Stanford University, Stanford, California (United States); Jones, Jennifer C. [Vaccine Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland (United States); Huang, Derek D. [Department of Internal Medicine, University of California-Los Angeles Olive View, Sylmar, California (United States); Le, Quynh-Thu; Hoppe, Richard T. [Department of Radiation Oncology, Stanford University, Stanford, California (United States); Donaldson, Sarah S., E-mail: sarah2@stanford.edu [Department of Radiation Oncology, Stanford University, Stanford, California (United States)

    2013-08-01

    Purpose: Low-dose radiation has become increasingly used in the management of indolent non-Hodgkin lymphoma (NHL), but has not been studied specifically for cases of ocular adnexal involvement. The objective of this study is to investigate the effectiveness of low-dose radiation in the treatment of NHL of the ocular adnexa. Methods and Materials: We reviewed the records of 20 NHL patients with 27 sites of ocular adnexal involvement treated with low-dose radiation consisting of 2 successive fractions of 2 Gy at our institution between 2005 and 2011. The primary endpoint of this study is freedom from local relapse (FFLR). Results: At a median follow-up time of 26 months (range 7-92), the overall response rate for the 27 treated sites was 96%, with a complete response (CR) rate of 85% (n=23) and a partial response rate of 11% (n=3). Among all treated sites with CR, the 2-year FFLR was 100%, with no in-treatment field relapses. The 2-year freedom from regional relapse rate was 96% with 1 case of relapse within the ipsilateral orbit (outside of the treatment field). This patient underwent additional treatment with low-dose radiation of 4 Gy to the area of relapse achieving a CR and no evidence of disease at an additional 42 months of follow-up. Orbital radiation was well tolerated with only mild acute side effects (dry eye, conjunctivitis, transient periorbital edema) in 30% of treated sites without any reports of long-term toxicity. Conclusions: Low-dose radiation with 2 Gy × 2 is effective and well tolerated in the treatment of indolent NHL of the ocular adnexa with high response rates and durable local control with the option of reirradiation in the case of locoregional relapse.

  3. Low Dose Radiation Hypersensitivity is Caused by p53-dependent Apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Enns, L; Bogen, K; Wizniak, J; Murtha, A; Weinfeld, M

    2004-04-08

    Exposure to environmental radiation and the application of new clinical modalities, such as radioimmunotherapy, have heightened the need to understand cellular responses to low dose and low-dose rate ionizing radiation. Many tumor cell lines have been observed to exhibit a hypersensitivity to radiation doses below 50 cGy, which manifests as a significant deviation from the clonogenic survival response predicted by a linear-quadratic fit to higher doses. However, the underlying processes for this phenomenon remain unclear. Using a gel microdrop/flow cytometry assay to monitor single cell proliferation at early times post irradiation, we examined the response of human A549 lung carcinoma, T98G glioma and MCF7 breast carcinoma cell lines exposed to gamma radiation doses from 0 to 200 cGy delivered at 0.18 and 22 cGy/min. The A549 and T98G cells, but not MCF7 cells, showed the marked hypersensitivity at doses <50 cGy. To further characterize the low-dose hypersensitivity, we examined the influence of low-dose radiation on cell cycle status and apoptosis by assays for active caspase-3 and phosphatidylserine translocation (annexin-V binding). We observed that caspase-3 activation and annexin-V binding mirrored the proliferation curves for the cell lines. Furthermore, the low-dose hypersensitivity and annexin-V binding to irradiated A549 and T98G cells were eliminated by treating the cells with pifithrin, an inhibitor of p53. When p53-inactive cell lines (2800T skin fibroblasts and HCT116 colorectal carcinoma cells) were examined for similar patterns, we found that there was no HRS and apoptosis was not detectable by annexin-V or caspase-3 assays. Our data therefore suggest that low-dose hypersensitivity is associated with p53-dependent apoptosis.

  4. Mechanisms of Low Dose Radiation-induced T helper Cell Function

    Energy Technology Data Exchange (ETDEWEB)

    Gridley, Daila S.

    2008-10-31

    Exposure to radiation above levels normally encountered on Earth can occur during wartime, accidents such as those at Three Mile Island and Chernobyl, and detonation of “dirty bombs” by terrorists. Relatively high levels of radiation exposure can also occur in certain occupations (low-level waste sites, nuclear power plants, nuclear medicine facilities, airline industry, and space agencies). Depression or dysfunction of the highly radiosensitive cells of the immune system can lead to serious consequences, including increased risk for infections, cancer, hypersensitivity reactions, poor wound healing, and other pathologies. The focus of this research was on the T helper (Th) subset of lymphocytes that secrete cytokines (proteins), and thus control many actions and interactions of other cell types that make up what is collectively known as the immune system. The Department of Energy (DOE) Low Dose Radiation Program is concerned with mechanisms altered by exposure to high energy photons (x- and gamma-rays), protons and electrons. This study compared, for the first time, the low-dose effects of two of these radiation forms, photons and protons, on the response of Th cells, as well as other cell types with which they communicate. The research provided insights regarding gene expression patterns and capacity to secrete potent immunostimulatory and immunosuppressive cytokines, some of which are implicated in pathophysiological processes. Furthermore, the photon versus proton comparison was important not only to healthy individuals who may be exposed, but also to patients undergoing radiotherapy, since many medical centers in the United States, as well as worldwide, are now building proton accelerators. The overall hypothesis of this study was that whole-body exposure to low-dose photons (gamma-rays) will alter CD4+ Th cell function. We further proposed that exposure to low-dose proton radiation will induce a different pattern of gene and functional changes compared to

  5. Rating the elderly with terminal cancer disease

    International Nuclear Information System (INIS)

    Full text: Introduction: In over 60 years are diagnosed more than 50% of tumors and 60% die because of this that only represents 20 % the total number of successes in this population group. However, currently there are few non-oncology geriatric patients who benefit of this model of care. This is because, in addition to palliative care have been developed mainly since Oncology, to it difficult to establish the concept of not being able to complete their basic survival and to predict the final stages of the disease chronicles are made ​​by different disciplines The intention of this study is to evaluate the variety oncology in the Department of Oncology at University Hospital and the focus on the Rating and care have been given to elderly patients with end-stage neoplastic disease or who are liable to care palliative for various reasons. Objective: • Determine the epidemiological profile of older adults with terminal cancer diagnosis attending Department of Hospital Oncology Clinic and if were evaluated globally and received palliative care. Methodology: • Design: Observational descriptive retrospective analytical component. • Universe: Young adults of both sexes attending the Oncology Department of the Hospital de Clinical in a period of the last 24 years • Sample: 191 Older adults of both sexes with oncological disease and 54 criteria that are terminally attended the Department of Oncology in the period of 24 years RESULTS: • The epidemiological characteristics of 191 elderly Less than half are predominantly male young seniors and the type of cancer most frequent pathology was i lung cancer, colon cancer, stomach cancer and unknown primary. More than half are female predominance of young and elderly oncological pathology type was most frequent cancer breast, colon, ovarian and lymphoma cancer • Less than half of older men terminalidad presented some criteria, being among the most frequent esophageal cancer with lung metastases of prostate cancer

  6. Radiation-induced stress effects following low dose exposure

    International Nuclear Information System (INIS)

    Complete text of publication follows. Recent advances in our understanding of effects of radiation on living cells suggest that fundamentally different mechanisms are operating at low doses compared with high doses. Also, acute low doses appear to involve different response mechanisms compared with chronic low doses. Both genomic instability and so called 'bystander effects' show many similarities with well known cellular responses to oxidative stress. These predominate following low dose exposures and are maximally expressed at doses as low as 5mGy. At the biological level this is not surprising. Chemical toxicity has been known for many years to show these patterns of dose response. Cell signaling and coordinated stress mechanisms appear to dominate acute low dose exposure to chemicals. Adaptation to chemical exposures is also well documented although mechanisms of adaptive responses are less clear. In the radiation field adaptive responses also become important when low doses are protracted or fractionated. Recent data from our group concerning bystander effects following multiple low dose exposures suggest that adaptive responses can be induced in cells which only receive signals from irradiated neighbours. We have data showing delayed and bystander effects in humans, rodents 3 fish species and in prawns following in vitro and/or in vivo irradiation of haematopoietic tissues and, from the aquatic groups, gill and skin/fin tissue. Bystander signals induced by radiation can be communicated from fish to fish in vivo and are detectable as early as the eyed egg stage, i.e. as soon as tissue starts to develop. Using proteomic approaches we have determined that the bystander and the direct irradiation proteomes are different. The former show significant upregulation of 5 proteins with anti-oxidant, regenerative and restorative functions while the direct radiation proteome has 2 upregulated proteins both involved in proliferation. These data have implications for

  7. Screenings of lung cancer with low dose spiral CT: results of a three year pilot study and design of the randomised controlled trial Italung-CT; Screening della neoplasia polmonare con TC spirale a bassa dose: risultati di uno studio pilota triennale e disegno dello studio clinico randomizzato Italung-CT

    Energy Technology Data Exchange (ETDEWEB)

    Picozzi, Giulia [Firenze Univ., Firenze (Italy). Radiodiagnostica I-Dipartimento di Fisiopatologia Clinica; Paci, Enrico [Azienda Ospedaliera Universitaria di Careggi, Firenze (Italy). Unita' di Epidemiologia Clinica e Descrittiva Centro per lo Studio e la Prevenzione Oncologica; Lopes Pegna, Andrea [Azienda Ospedaliera Universitaria di Careggi, Firenze (Italy). U.O. Pneumologia] [and others

    2005-02-01

    Purpose: To report the results of a three-year observational pilot study of lung cancer screening with low dose computed tomography (CT) and to present the study design of a randomised clinical trial named as Italung CT. Materials and methods: Sixty (47 males and 13 females, mean age 64{+-}4.5 years) heavy smokers (at least 20 packs-year) underwent three low-dose spiral CT screening tests one year apart on a single slice or multislice CT scanner. Indeterminate nodules were managed according to the recommendations of the Early Lung Cancer Action Project. Results: Indeterminate nodules were observed in 33 (55%) of the subjects (60% at the baseline screening test, 24% at the first annual test and 16% at the second annual test). The size of the largest indeterminate nodule was <5mm in diameter in 20 subjects. 10 of whom showed the nodule at the baseline test. Forty-five subjects (75%) completed the first annual test and 42 (70%) the second annual test. One (1.6%) prevalent lung cancer (adenosquamous carcinoma) and one (2.2%) incident lung cancer (small cell cancer at the first annual examination) were observed, as well as pulmonary localisation of Hodgkin's lymphoma (at the second annual test). In addition, one subject underwent lung surgery for a chondromatous hamartoma. Conclusions: The results of the pilot study are substantially in line with those of other observational studies of greater sample size. This justifies optimism about the reliability of the results in the screened arm of the Italung Ct trial which hast just began. [Italian] Scopo: Riportare i risultati di uno studio pilota osservazionale di screening della neoplasia polmonare con TC a bassa dose della durata di tre anni e presentare il disegno dello studio clinico randomizzato Italung-CT. Materiale e metodi: Sessanta (47 uomini e 13 donne, eta' media 64{+-}4,5 anni) forti fumatori (almeno 20 pacchetti/anno) sono stati sottoposti ad un esame basale e a due controlli annuali con TC single o

  8. CLINICAL STUDY OF LOW-DOSE KETAMINE ASSOCIATING MORPHINE PATIENT CON-TROL EPIDURAL OR SUBCUTANEOUS ANALGESIA FOR MODERATE AND SEVERE LATE PHASE CANCER PAIN PATIENT%小剂量氯胺酮辅助吗啡硬膜外/皮下自控镇痛用于顽固性中、重度晚期癌痛治疗的临床研究

    Institute of Scientific and Technical Information of China (English)

    陈付强; 胡丹; 时飞; 谢平; 王昕; 艾登斌

    2009-01-01

    Objective:To observe the analgesic effects and the side effects of low-dose ketamine associa- ting morphine with patient control epidural analgesia(PCEA)and patient control subcutaneous analgesia (PCSA)for patients late cancer pain.Methods:54 cases late-phase cancer pain patients were divided in to two groups,with low-dose ketamine associating morphine PCEA Was used in the first group and low- dose ketamine associating morphine PCSA in the second group.The VAS(Visual Analogue Scale)Was used to evaluate the pain level,and the side effects in two groups.Results:The pain degrees of the two groups were alleviated significantly,the VAS at every period were no different(P>0.05),the morphine and ketamine dosage in the PCSA group was more than that in the PCEA group.The life satisfactory rate in PCEA group Was higher obviously than that in PCSA group;side effects such as the incidence of nause- a,vomiting,somnolence,itch and urine retention in the PCSA group was higher than those in the PCEA group;the incidence of respiration depression and hallucination was no different between the two groups. Conclusions:Both low-dose ketamine associating morphine with patient-control epidural analgesia (PCEA)and PCSA Call provide patient with safe and effective pain relief for moderate to severe late- phase cancer pain.PCEA is an optimas approach for moderate to severe late-phase concer pain with bet- ter pain relief and less side-effect and PCSA can serve as a complementary analgesia.%目的:观察小剂量氯胺酮辅助吗啡硬膜外或皮下自控镇痛(PCEA/PCSA)用于顽固性中、重度晚期癌痛患者的可行性及止痛效果.方法:选择54例中、重度晚期癌痛患者,均为虽经三阶梯药物治疗方案治疗未能很好地控制疼痛,同时毒副作用较大的患者.按是否可以行硬膜外穿刺置管分成两组,硬膜外自控镇痛(PCEA)组(n=28例)和皮下自控镇痛(PCSA)组(n=26例).采用硬膜外自控镇痛组,镇痛液为200ml,内含吗啡20mg

  9. Clinical Study of Low-dose 70kv.50mAs MSCT Perfusion Imaging in the Evaluation of Patients with Lung Cancer%70KV.50mAs多层螺旋CT低辐射灌注扫描在肺癌诊治中的应用

    Institute of Scientific and Technical Information of China (English)

    封俊; 高德培; 李振辉; 董兴祥; 朱婵

    2016-01-01

    目的:探讨70KV.50mAs多层螺旋CT低辐射灌注扫描在肺癌诊治中应用的可行性。方法对发现肺部孤立性肿瘤进行70KV.50mAs多层螺旋CT低辐射灌注扫描。搜集有手术或穿刺病理证实45例患者,鳞癌15例,腺癌23例,小细胞性肺癌7例。利用体部肺肿瘤灌注软件对图像进行后处理,根据非去卷积模型法获得相应肿瘤灌注彩图,测定肿瘤的对比剂达峰时间(TTP)、血流量(BF)、血容量(BV)、渗透性(PMB)。结果鳞癌、腺癌、小细胞性肺癌的TTP(s)分别是:15.62、17.91、16.89;鳞癌、腺癌、小细胞性肺癌的BF(ml/100ml/min)分别是:91.72、77.27、90.60;鳞癌、腺癌、小细胞性肺癌的BV(ml/100ml)分别是:8.06、8.94、11.94;鳞癌、腺癌、小细胞性肺癌的PMB(ml/100ml/min)分别是:13.79、15.17、13.95。结论70KV.50mAs低辐射灌注扫描方法能有效降低射线对患者的辐射,该方法获得的肺部肿瘤的灌注数据可以作为临床分析肺部肿瘤的血供及肿瘤血液灌注的一种手段。%Objective To investigate the clinical value and feasibility of low-dose 70kv.50mAs MSCT perfusion imaging in the evaluation of patients with lung cancer. Methods Retrospectively studied 45 cases(squamous carcinoma 15 cases, adenocarcinoma 23cases, small cell carcinoma 7cases) lung cancer confirmed by operation and pathology, these patients were undergone low-dose(70kv.50mAs)MDCT perfusion scanning before operation. The original images were processed by perfusion software. The value of time to peak(TTP), blood flow (BF), blood volume (BV) and permeability (PMB) were calculated, and gained perfusion image.Results The TTP (s) of squamous carcinoma, adenocarcinoma, small cell carcinoma were 15.62、17.91、16.89. The BF (ml/100ml/min) of squamous carcinoma, adenocarcinoma, small cell carcinoma were 91.72, 77.27, 90.60;The BV (ml/100ml) of squamous carcinoma, adenocarcinoma, small cell carcinoma were 8.06, 8.94, 11

  10. The relevance of radiation induced bystander effects for low dose radiation carcinogenic risk

    International Nuclear Information System (INIS)

    Full text: Where epidemiology studies lack the ability to prescribe radiation doses, customise sample sizes and replicate findings, radiobiology experiments provide greater flexibility to control experimental conditions. This control simplifies the process of answering questions concerning carcinogenic risk after low dose radiation exposures. However, the flexibility requires critical evaluation of radiobiology findings to ensure that the right questions are being asked, the experimental conditions are relevant to human exposure scenarios and that the data are cautiously interpreted in the context of the experimental model. In particular, low dose radiobiology phenomena such as adaptive responses, genomic instability and bystander effects need to be investigated thoroughly, with continual reference to the way these phenomena might occur in the real world. Low dose radiation induced bystander effects are of interest since their occurrence in vivo could complicate the shape of the radiation dose-response curve in the low dose range for a number of biological endpoints with subsequent effects on radiation-induced cancer risk. Conversely, radiation-induced abscopal effects implicate biological consequences of radiation exposure outside irradiated volumes, and complicate the notion of effective dose calculations. Achieving a consensus on the boundaries that distinguish the radiobiology phenomena of bystander and abscopal effects will aid progress towards understanding their relevance to in vivo radiation exposures. A proposed framework for discussing bystander effects and abscopal effects in their appropriate context will be outlined, with a discussion on the future investigation of radiation-induced bystander effects. Such frameworks can assist the integration of results from experimental radiobiology to risk evaluation and management practice. This research was funded by the Low Dose Radiation Research Program, BioI. and Environ. Research, US Dept. of Energy, Grant DE

  11. Low dose Mifepristone (100 mg for medical termination of pregnancy

    Directory of Open Access Journals (Sweden)

    Shikha Seth

    2011-02-01

    Full Text Available Background: Abortion is the most common entity in the practice of obstetrics and gynaecology. Different methods and modes have been opted for until now to find an effective regimen with the least complications. We have tried the minimal dose (100 mg of Mifepristone (PO instead of the presently recommended 200 mg for medical abortion in early first trimester cases. Objectives: The objective of the study was to determine the efficacy of low dose (100 mg Mifepristone for medical termination of early pregnancy with oral Misoprostol 800 μg, 24 hours later.Design: A prospective analytical study was conducted on a population of 82 early-pregnant patients who have requested medical abortions.Method: Pregnant women of less than 56 days gestation age from their last menstrual period, requesting medical abortion were selected over a period of 14 months from January 2007 to March 2008. They were given 100 mg Mifepristone orally on Day-1, followed by 800 μg Misoprostol orally 24 hours later on Day-2, keeping the patient in the ward for at least 6 hours. Abortion interval, success rate, post-abortion bleeding and side-effects were noted. Success was defined as complete uterine evacuation without the need for surgical intervention.Results: The total success rate of this minimal dose Mifepristone regimen was 96.25%. Pain and nausea were the predominant side-effects noted. In total 72 (90% women had completely aborted within 5 hours of taking Misoprostol. Three (3.75% women only required suction aspiration, hence termed as failed medical abortion. The abortion interval increased with the gestation age. All three failures were of the more-than-42-day gestational age group. The overall mean abortion interval was 4.68 ± 5.32 hours.Conclusion: Mifepristone 100 mg, followed 24 hours later by Misoprostol 800 μg orally, is a safe and effective regimen for medical abortion.

  12. Low-Dose Risk, Decisions, and Risk Communication

    International Nuclear Information System (INIS)

    To conduct basic research on how people receive, evaluate, and form positions on scientific information and its relationship to low-dose radiation exposure. There are three major areas of study in our research program. First is the development of theories, frameworks and concepts essential to guiding data collection and analysis. The second area is a program of experimental studies on risk perception, evaluation of science information, and the structure of individual positions regarding low dose exposures. This involves the study of existing knowledge and the evaluation of science information presented within a variety of formats, as educational information, news media stories, and alternative communication methods (personal contact, small group interaction, email and internet, etc.). Third is the community-level studies to examine and record how the social conditions, under which science communications take place, influence the development of attitudes and opinions about: low- dose exposures, the available management options, control of radiation risks, and preferences for program and policy goals

  13. Stimulation effect of early growth in crops by low dose radiation

    International Nuclear Information System (INIS)

    Germination rate and early growth in crop such as rice,soybean,and perilla were observed after irradiation of γ-ray (Co-60) in order to determine the effects of low does radiation. The low dose radiation was able to improve the early growth in crops and their agricultural characters. Germination rate of 2Gy-irradiatied rice seeds was high and also were seeding height and fresh weight of the 0.5 Gy-irradiated. Germination rate and early growth of soybean were high in 4Gy-irradiated group. Perilla gew of so promisingly after after low dose irradiation, however there slightly increasing effects on germination rate, seeding height and fresh weight at 2Gt-, 1Gy-, and 1Gy irradiated group, respectively. (author)

  14. Seizures associated with low-dose tramadol for chronic pain treatment

    Science.gov (United States)

    Beyaz, Serbülent Gökhan; Sonbahar, Tuğba; Bayar, Fikret; Erdem, Ali Fuat

    2016-01-01

    The management of cancer pain still poses a major challenge for clinicians. Tramadol is a centrally acting synthetic opioid analgesic. Its well-known side effects include nausea, vomiting, and dizziness; seizures are a rare side effect. Some reports have found that tramadol triggers seizure activity at high doses, whereas a few preclinical studies have found that this seizure activity is not dose-related. We herein present a case involving a patient with laryngeal cancer who developed seizures while on low-dose oral tramadol. PMID:27212778

  15. Commentary: ethical issues of current health-protection policies on low-dose ionizing radiation.

    Science.gov (United States)

    Socol, Yehoshua; Dobrzyński, Ludwik; Doss, Mohan; Feinendegen, Ludwig E; Janiak, Marek K; Miller, Mark L; Sanders, Charles L; Scott, Bobby R; Ulsh, Brant; Vaiserman, Alexander

    2014-05-01

    The linear no-threshold (LNT) model of ionizing-radiation-induced cancer is based on the assumption that every radiation dose increment constitutes increased cancer risk for humans. The risk is hypothesized to increase linearly as the total dose increases. While this model is the basis for radiation safety regulations, its scientific validity has been questioned and debated for many decades. The recent memorandum of the International Commission on Radiological Protection admits that the LNT-model predictions at low doses are "speculative, unproven, undetectable and 'phantom'." Moreover, numerous experimental, ecological, and epidemiological studies show that low doses of sparsely-ionizing or sparsely-ionizing plus highly-ionizing radiation may be beneficial to human health (hormesis/adaptive response). The present LNT-model-based regulations impose excessive costs on the society. For example, the median-cost medical program is 5000 times more cost-efficient in saving lives than controlling radiation emissions. There are also lives lost: e.g., following Fukushima accident, more than 1000 disaster-related yet non-radiogenic premature deaths were officially registered among the population evacuated due to radiation concerns. Additional negative impacts of LNT-model-inspired radiophobia include: refusal of some patients to undergo potentially life-saving medical imaging; discouragement of the study of low-dose radiation therapies; motivation for radiological terrorism and promotion of nuclear proliferation. PMID:24910586

  16. Some remarks on the significance of low doses

    International Nuclear Information System (INIS)

    The criteria of the present system of individual dose limitation are considered as well as the evolution of the limiting values. The assumption of the linearity of the dose-effect relationship without any threshold is probably the best approach to adopt for recommendations in radiation protection and for accounting the doses acquired by exposure to ionizing radiation. On the other hand the present evaluation of the natural background could imply a different dose-effect relationship in the low doses region and perhaps the existence of a threshold. Therefore the extrapolations which are usually made after exposures of different groups of people to low doses cannot be considered as scientifically sound. (author)

  17. Mammalian Tissue Response to Low Dose Ionizing Radiation: The Role of Oxidative Metabolism and Intercellular Communication

    Energy Technology Data Exchange (ETDEWEB)

    Azzam, Edouard I

    2013-01-16

    The objective of the project was to elucidate the mechanisms underlying the biological effects of low dose/low dose rate ionizing radiation in organs/tissues of irradiated mice that differ in their susceptibility to ionizing radiation, and in human cells grown under conditions that mimic the natural in vivo environment. The focus was on the effects of sparsely ionizing cesium-137 gamma rays and the role of oxidative metabolism and intercellular communication in these effects. Four Specific Aims were proposed. The integrated outcome of the experiments performed to investigate these aims has been significant towards developing a scientific basis to more accurately estimate human health risks from exposures to low doses ionizing radiation. By understanding the biochemical and molecular changes induced by low dose radiation, several novel markers associated with mitochondrial functions were identified, which has opened new avenues to investigate metabolic processes that may be affected by such exposure. In particular, a sensitive biomarker that is differentially modulated by low and high dose gamma rays was discovered.

  18. The bibliometric analysis of literatures on low-dose CT in CNKI

    International Nuclear Information System (INIS)

    Objective: The purposes of this study were to evaluate the characteristics and rule of the development in national low -dose CT examination, and to supply a useful reference for future studies. Materials and Methods: The journal articles in CNKI which were included by China Academic Journal Network Publishing Database (CAJD) from 2002 to 2011 were processed with Thomson Data Analyzer (TDA). Seven aspects were analyzed: time, authors, funds for scientific research, areal distribution, institutions, authors, and keywords. Results: A total 3148 journal articles on low-dose CT examination and 7352 authors were found. The cooperative rate and degree were 63, 48% and 2.34, respectively. The famous authors were those who published more than 3 articles. Authors were from 33 areas, 471 institutions of 8 systems. Beijing and Shanghai were the most productive areas, publishing 45.9% articles. There were 10 core journals in this research area, 868 articles were funded by certain