WorldWideScience

Sample records for partial brain radiation

  1. Brain radiation - discharge

    Science.gov (United States)

    Radiation - brain - discharge; Cancer - brain radiation; Lymphoma - brain radiation; Leukemia - brain radiation ... Decadron) while you are getting radiation to the brain. It may make you hungrier, cause leg swelling ...

  2. Feasibility of using the computed tomography dose indices to estimate radiation dose to partially and fully irradiated brains in pediatric neuroradiology examinations

    International Nuclear Information System (INIS)

    Januzis, Natalie; Nguyen, Giao; Yoshizumi, Terry T; Frush, Donald P; Hoang, Jenny K; Lowry, Carolyn

    2015-01-01

    The purpose of this study was two-fold: (a) to measure the dose to the brain using clinical protocols at our institution, and (b) to develop a scanner-independent dosimetry method to estimate brain dose. Radiation dose was measured with a pediatric anthropomorphic phantom and MOSFET detectors. Six current neuroradiology protocols were used: brain, sinuses, facial bones, orbits, temporal bones, and craniofacial areas. Two different CT vendor scanners (scanner A and B) were used. Partial volume correction factors (PVCFs) were determined for the brain to account for differences between point doses measured by the MOSFETs and average organ dose. The CTDI vol and DLP for each protocol were recorded. The dose to the brain (mGy) for scanners A and B was 10.7 and 10.0 for the brain protocol, 7.8 and 3.2 for the sinus, 10.2 and 8.6 for the facial bones, 7.4 and 4.7 for the orbits and 1.6 and 1.9 for the temporal bones, respectively. On scanner A, the craniofacial protocol included a standard and high dose option; the dose measured for these exams was 3.9 and 16.9 mGy, respectively. There was only one craniofacial protocol on scanner B; the brain dose measured on this exam was 4.8 mGy. A linear correlation was found between DLP and brain dose with the conversion factors: 0.049 (R 2 = 0.87), 0.046 (R 2 = 0.89) for scanner A and B, and 0.048 (R 2 = 0.89) for both scanners. The range of dose observed was between 1.8 and 16.9 mGy per scan. This suggests that brain dose estimates may be made from DLP. (paper)

  3. Radiation Injury to the Brain

    Science.gov (United States)

    ... Hits since January 2003 RADIATION INJURY TO THE BRAIN Radiation treatments affect all cells that are targeted. ... fractions, duration of therapy, and volume of [healthy brain] nervous tissue irradiated influence the likelihood of injury. ...

  4. Exergy of partially coherent thermal radiation

    International Nuclear Information System (INIS)

    Wijewardane, S.; Goswami, Yogi

    2012-01-01

    Exergy of electromagnetic radiation has been studied by a number of researchers for well over four decades in order to estimate the maximum conversion efficiencies of thermal radiation. As these researchers primarily dealt with solar and blackbody radiation, which have a low degree of coherence, they did not consider the partial coherence properties of thermal radiation. With the recent development of surface structures, which can emit radiation with high degree of coherence, the importance of considering the partial coherent properties in exergy calculation has become a necessity as the coherence properties directly influence the entropy of the wave field. Here in this paper we derive an expression for the exergy of quasi-monochromatic radiation using statistical thermodynamics and show that it is identical with the expressions derived using classical thermodynamics. We also present a method to calculate the entropy, thereby the exergy of partially coherent radiation using statistical thermodynamics and a method called matrix treatment of wave field. -- Highlights: ► Considered partial coherence of radiation for the first time to calculate exergy. ► The importance of this method is emphasized with energy conversion examples. ► Derived an expression for the exergy of radiation using statistical thermodynamics. ► Adopted a method to calculate intensity of statistically independent principle wave.

  5. Partial radiative capture of resonance neutrons

    International Nuclear Information System (INIS)

    Samour, C.

    1969-01-01

    The radiative capture of resonance neutrons has been studied near the Saclay linac between 0.5 and 700 eV with time-of-flight method and a Ge(Li) detector. 195 Pt + n and 183 W + n allow the study of the distribution of partial radiative widths and their eventual correlation and also the variation of γ i > with E γ . The mean values of Ml and El transition intensities are compared in several tin isotopes. Interference effects, either between resonances or between direct capture and resonant capture are found in 195 Pt + n, 197 Au + n and 59 Co + n. The excited level schemes of a great deal of nuclei are obtained and compared with theoretical predictions. This study has been completed by an analysis of thermal spectrum. (author) [fr

  6. Radiation therapy of brain metastases

    Energy Technology Data Exchange (ETDEWEB)

    Sauer, R; Huenig, R [Kantonsspital Basel (Switzerland). Universitaetsinstitut fuer Medizinische Radiologie

    1975-08-01

    Experiences are reported obtained with radiation therapy of brain metastases in 121 patients during the last 15 years. The treatment to a lesser extent aimed at prolongation of survival but much more at the attempt to alleviate troubles and to spare pain. The indication thus involved medical points of view as well as ethical ones. The radiotherapy of cerebral metastases comprises the whole cranial volume and requires a focal dose of minimally 4,000 R within four weeks. In 53% of the patients, the regression of neurological symptoms was considerable, in 18% even complete, partly beginning already after a few days of treatment. The number of recurrences was small. Under conditions of rigorous indication, the radiation therapy of brain metastases offers a rewarding palliative measure.

  7. Radiation therapy of brain tumor

    International Nuclear Information System (INIS)

    Sung, K. J.; Lee, D. H.; Park, C. Y.

    1980-01-01

    One hundred and six cases of brain tumors were treated at the Yonsei Cancer Center from January 1972 to August 1978 by Co-60 teletherapy unit. We analyses their clinical findings, histopathological findings, treatment and results. In those cases which computerized tomography had been used before and after radiation therapy, changes in tumor size and the presence of edema or necrosis following treatment was evaluated. 1. Among 106 cases, 90 cases were primary brain tumors and 16 cases were metastatic brain tumors. Pituitary tumors (38), glioma (34) and pinealoma (10) composed of most of primary brain tumors. 2. Post treatment follow-up was possible in 38 cases more than 1 years. Four among 11 cases of giloma expired and survivors had considerable neurological symptoms except 2 cases. Sixty five percent (12/20) of pituitary tumors showed improvement of visual symptoms and all cases (7) of pinealoma which post treatment follow-up was possible, showed remarkable good response. 3. Findings of CT scan after radiation treatment were compatible with results of clinical findings and post treatment follow-up. It showed complete regression of tumor mass in one case of pinealoma and medulloblastoma. One case of pituitary tumor showed almost complete regression of tumor mass. It also showed large residual lesion in cases of glioblastoma multiforme and cystic astrocytoma.

  8. Radiation-induced brain damage in children

    International Nuclear Information System (INIS)

    Oi, Shizuo; Kokunai, Takashi; Ijichi, Akihiro; Matsumoto, Satoshi; Raimondi, A.J.

    1990-01-01

    The nature and sequence of the radiation-induced changes in the brain were studied postmortem in 34 children with glioma, 22 of whom underwent central nervous system radiation therapy. Twenty received whole-brain or whole-neuroaxis radiation at a total mean dosage of 4063 cGy. Brain tissue alternations were analyzed histologically by means of various staining methods, including immunohistochemical techniques. The histological features of irradiated brains were compared with those of non-irradiated brains. Microscopic findings included demyelination (seven cases), focal necrosis (six cases), cortical atrophy (four cases), endothelial proliferation (four cases), and telangiectatic vascular proliferation with vascular thickening and oozing of a thick fluid (one case). Such findings were rare in non-irradiated patients. Demyelination was observed earliest in a patient who died 5 months after radiation therapy and was more common after 9 months. Focal necrosis was first observed 9 months post-irradiation but was more advanced and extensive after 1 year. Calcified foci were found only after 60 months. Various vascular changes such as vascular thickening and thrombosis suggested ischemic insult to the brain as a late effect of radiation injury. The results of this study suggest that the immature brain may be more sensitive to radiation than is the adult brain, and that the manifestations of radiation-induced injury depend on the time elapsed after irradiation. (author)

  9. Quantification of brain tissue through incorporation of partial volume effects

    Science.gov (United States)

    Gage, Howard D.; Santago, Peter, II; Snyder, Wesley E.

    1992-06-01

    This research addresses the problem of automatically quantifying the various types of brain tissue, CSF, white matter, and gray matter, using T1-weighted magnetic resonance images. The method employs a statistical model of the noise and partial volume effect and fits the derived probability density function to that of the data. Following this fit, the optimal decision points can be found for the materials and thus they can be quantified. Emphasis is placed on repeatable results for which a confidence in the solution might be measured. Results are presented assuming a single Gaussian noise source and a uniform distribution of partial volume pixels for both simulated and actual data. Thus far results have been mixed, with no clear advantage being shown in taking into account partial volume effects. Due to the fitting problem being ill-conditioned, it is not yet clear whether these results are due to problems with the model or the method of solution.

  10. Ionising radiation and the developing human brain

    International Nuclear Information System (INIS)

    Schull, W.J.

    1991-01-01

    This article reviews the effects of radiation exposure of the developing human brain. Much of the evidence has come from the prenatally exposed in Hiroshima and Nagasaki. The effects on development age, mental retardation, head size, neuromuscular performance, intelligence tests, school performance and the occurrence of convulsions are discussed. Other topics covered include the biological nature of the damage to the brain, risk estimates in human and problems in radiation protection. (UK)

  11. Full scale IQ (FSIQ) changes in children treated with whole brain and partial brain irradiation. A review and analysis

    International Nuclear Information System (INIS)

    Fuss, M.; Poljanc, K.; Hug, E.B.; Loma Linda Univ. Medical Center, Loma Linda, CA

    2000-01-01

    The purpose of this analysis was to assess current knowledge, with focus on correlation with radiation dose, irradiated volume and age. Method: Full Scale IQ (FSIQ) data, representing 1,938 children, were derived from 36 publications and analyzed as to radiation dose, irradiated volume, and age. Results: FSIQ after whole brain irradiation showed a non-linear decline as dosage increased. The dose-effect relationship was age-related, with more pronounced FSIQ decline at younger age. FSIQ test results below the normal level ( 50 Gy. Conclusion: The collected data suggest that whole brain irradiation doses of 18 and 24 Gy have no major impact on intellectual outcome in children older than age 6, but may cause impairment in younger children. Doses >24 Gy comprise a substantial risk for FSIQ decline, even in older children. At equal dose levels, partial brain irradiation is less damaging than whole brain irradiation. The authors are well aware of limitations in the interpretation of data collected for the current review. (orig.) [de

  12. Partial sleep in the context of augmentation of brain function.

    Directory of Open Access Journals (Sweden)

    Ivan N. Pigarev

    2014-05-01

    Full Text Available Inability to solve complex problems or errors in decision making is often attributed to poor brain processing, and raises the issue of brain augmentation. Investigation of neuronal activity in the cerebral cortex in the sleep-wake cycle offers insights into the mechanisms underlying the reduction in mental abilities for complex problem solving. Some cortical areas may transit into a sleep state while an organism is still awake. Such local sleep would reduce behavioral ability in the tasks for which the sleeping areas are crucial. The studies of this phenomenon have indicated that local sleep develops in high order cortical areas. This is why complex problem solving is mostly affected by local sleep, and prevention of local sleep might be a potential way of augmentation of brain function. For this approach to brain augmentation not to entail negative consequences for the organism, it is necessary to understand the functional role of sleep. Our studies have given an unexpected answer to this question. It was shown that cortical areas that process signals from extero- and proprioreceptors during wakefulness, switch to the processing of interoceptive information during sleep. It became clear that during sleep all computational power of the brain is directed to the restoration of the vital functions of internal organs. These results explain the logic behind the initiation of total and local sleep. Indeed, a mismatch between the current parameters of any visceral system and the genetically determined normal range would provide the feeling of tiredness, or sleep pressure. If an environmental situation allows falling asleep, the organism would transit to a normal total sleep in all cortical areas. However, if it is impossible to go to sleep immediately, partial sleep may develop in some cortical areas in the still behaviorally awake organism. This local sleep may reduce both the intellectual power and the restorative function of sleep for visceral

  13. Radiation damage to the brain: neuropsychiatric aspects

    International Nuclear Information System (INIS)

    McMahon, T.; Vahora, S.

    1986-01-01

    Although radiation necrosis of the brain is a recognized complication of irradiation of the central nervous system, the psychiatric aspects of this phenomenon are less well defined. Two cases of radiation necrosis in which psychiatric symptoms were a prominent part of the clinical picture are presented. Factors that determine the evolution and clinical presentation of radiation necrosis are reviewed. In particular, the role of the consultation psychiatrist in the diagnosis and management of such patients is discussed

  14. Radiation-induced brain injury: A review

    Directory of Open Access Journals (Sweden)

    Michael eRobbins

    2012-07-01

    Full Text Available Approximately 100,000 primary and metastatic brain tumor patients/year in the US survive long enough (> 6 months to experience radiation-induced brain injury. Prior to 1970, the human brain was thought to be highly radioresistant; the acute CNS syndrome occurs after single doses > 30 Gy; white matter necrosis occurs at fractionated doses > 60 Gy. Although white matter necrosis is uncommon with modern techniques, functional deficits, including progressive impairments in memory, attention, and executive function have become important, because they have profound effects on quality of life. Preclinical studies have provided valuable insights into the pathogenesis of radiation-induced cognitive impairment. Given its central role in memory and neurogenesis, the majority of these studies have focused on the hippocampus. Irradiating pediatric and young adult rodent brains leads to several hippocampal changes including neuroinflammation and a marked reduction in neurogenesis. These data have been interpreted to suggest that shielding the hippocampus will prevent clinical radiation-induced cognitive impairment. However, this interpretation may be overly simplistic. Studies using older rodents, that more closely match the adult human brain tumor population, indicate that, unlike pediatric and young adult rats, older rats fail to show a radiation-induced decrease in neurogenesis or a loss of mature neurons. Nevertheless, older rats still exhibit cognitive impairment. This occurs in the absence of demyelination and/or white matter necrosis similar to what is observed clinically, suggesting that more subtle molecular, cellular and/or microanatomic modifications are involved in this radiation-induced brain injury. Given that radiation-induced cognitive impairment likely reflects damage to both hippocampal- and non-hippocampal-dependent domains, there is a critical need to investigate the microanatomic and functional effects of radiation in various brain

  15. Delayed development of radiation sickness in animals following partial exposure

    International Nuclear Information System (INIS)

    Vershinina, S.F.; Markochev, A.V.

    1995-01-01

    Causes of reduction of the life span of animals after partial exposure of the head, thorax, and abdomen are analyzed. Pulmonosclerosis and cardiosclerosis were mainly responsible for animal death following partial radiation exposure of the thorax; these conditions appreciably shortened the life span of the animals. After exposure of the head deaths were due to pneumonias which negligibly reduced the duration of life. Exposure of the abdomen led to the development of diabetes mellitus which shortened the life span by half. 18 refs., 1 tab

  16. Tumor sterilization dose and radiation induced change of the brain tissue in radiotherapy of brain tumors

    International Nuclear Information System (INIS)

    Yoshii, Yoshihiko; Maki, Yutaka; Takano, Shingo

    1987-01-01

    Ninety-seven patients with brain tumors (38 gliomas, 26 brain metastases, 18 sellar tumors, 15 others) were treated by cobalt gamma ray or proton radiotherapy. In this study, normal brain injury due to radiation was analysed in terms of time-dose-fractionation (TDF), nominal standard dose (NSD) by the Ellis formula and NeuNSD by a modification in which the N exponent was -0.44 and the T exponent was -0.06. Their calculated doses were analysed in relationship to the normal brain radiation induced change (RIC) and the tumor sterilization dose. All brain tumors with an exception of many patients with brain metastases were received a surgical extirpation subtotally or partially prior to radiotherapy. And all patients with glioma and brain metastasis received also immuno-chemotherapy in the usual manner during radiotherapy. The calculated dose expressed by NeuNSD and TDF showed a significant relationship between a therapeutic dose and a postradiation time in terms of the appearance of RIC. It was suggested that RIC was caused by a dose over 800 in NeuNSD and a dose over 70 in TDF. Furthermore, it was suggested that an aged patient and a patient who had the vulnerable brain tissue to radiation exposure in the irradiated field had the high risk of RIC. On the other hand, our results suggested that the tumor sterilization dose should be over 1,536 NeuNSD and the irradiated method should be further considered in addition to the radiobiological concepts for various brain tumors. (author)

  17. Influence of radiation on the developing brain

    International Nuclear Information System (INIS)

    Gao Weimin; Zhou Xiangyan

    1997-01-01

    An outline of current status in study on the influence of radiation on the developing brain was given based on data from both human and animals. Analysis was made in 5 aspects, such as the behaviour of nervous, changes on cellular and molecular levels, apoptosis of cells, and the adaptive reaction, which could be helpful for further understanding the influences of prenatal exposure on the developing brain

  18. Radiation therapy of brain metastases

    International Nuclear Information System (INIS)

    Obata, Yasunori; Morita, Kozo; Watanabe, Michiko; Niwa, Kokichi

    1982-01-01

    From January 1974 to December 1980, 104 patients with brain metastases were treated by irradiation to the whole brain. The results of treatment and the relation between CT images and effectiveness of irradiation were analized. The lung was the most common site of the primary tumor (67/104, 64.4%). The breast was a distant second in frequency (13/104, 12.5%) and fewer cases had other primary tumors (24/104, 23.1%). There were 63 males and 41 females. Their mean age was 56.0 years old. The interval between onset of symptoms from primary disease and of those from the brain metastases were 26.5 months for the breast cancer, 7.6 months for undifferentiated carcinoma of the lung and 13.2 months for all patients. Significant neurologic improvement was obtained in 85.7% of the patients (86 cases) irradiated as previous plans. The survival for the entire group of patients (86 cases) was 60.5% at 3 months, 31.4% at 6 months, 11.6% at 12 months an 3.5% at 18 months. Multiplicity of the metastatic brain tumror did not affect the prognosis but the control of the primary lesion affected the prognosis. The CT images of 41 cases before treatment revealed the enhanced mass was mainly homogeneous for the case with the breast cancer and mainly ring like for the case with squamous cell carcinoma of the lung. But the characters of the enhanced mass did not affect the prognosis. On the other hand, the analysis of the CT images of 37 cases before and after the treatment revealed the relation between the tumor regression and the improvement in neurologic symptoms. (J.P.N.)

  19. Delayed radiation necrosis of the brain simulating a brain tumor

    International Nuclear Information System (INIS)

    Ikeda, Hiroya; Kanai, Nobuhiro; Kamikawa, Kiyoo

    1976-01-01

    Two cases of delayed radiation necrosis of the brain are reported. Case 1 was a 50-year-old man who had right hemiparesis and disorientation 26 months after Linac irradiation (5,000 rad), preceded by an operation for right maxillar carcinoma. A left carotid angiogram demonstrated a left temporal mass lesion, extending to the frontal lobe. Case 2 was a 41-year-old man who had previously had an operation for right intraorbital plasmocytoma, followed by two Co irradiations (6,400 rad, and 5,000 rad). He had the signs and symptoms of intracranial hypertension 36 months after his last irradiation. A left carotid angiogram demonstrated a left temporal mass lesion. Both cases were treated by administration of steroid hormone (which alleviated the signs and symptoms) and by temporal lobectomy. Microscopic examinations showed necrosis of the brain tissues associated with hyaline degeneration of blood vessel walls and perivascular cell infiltration. The signs and symptoms of intracranial hypertension subsided postoperatively. Thirteen other cases the same as ours were collected from literature. They showed the signs and symptoms simulating a brain tumor (like a metastatic brain tumor) after irradiation to extracranial malignant tumors. Diagnosis of radiation necrosis was made by operation or autopsy. A follow-up for a long time is necessary, because the pathological changes in the brain may be progressive and extending in some cases, although decompressive operations for mass lesions give excellent results. (auth.)

  20. Radiation-induced brain injury: A review

    Energy Technology Data Exchange (ETDEWEB)

    Greene-Schloesser, Dana; Robbins, Mike E.; Peiffer, Ann M.; Shaw, Edward G. [Department of Radiation Oncology, Wake Forest School of Medicine,, Winston-Salem, NC (United States); Brain Tumor Center of Excellence, Wake Forest School of Medicine,, Winston-Salem, NC (United States); Wheeler, Kenneth T. [Brain Tumor Center of Excellence, Wake Forest School of Medicine,, Winston-Salem, NC (United States); Department of Radiology, Wake Forest School of Medicine,, Winston-Salem, NC (United States); Chan, Michael D., E-mail: mrobbins@wakehealth.edu [Department of Radiation Oncology, Wake Forest School of Medicine,, Winston-Salem, NC (United States); Brain Tumor Center of Excellence, Wake Forest School of Medicine,, Winston-Salem, NC (United States)

    2012-07-19

    Approximately 100,000 primary and metastatic brain tumor patients/year in the US survive long enough (>6 months) to experience radiation-induced brain injury. Prior to 1970, the human brain was thought to be highly radioresistant; the acute CNS syndrome occurs after single doses >30 Gy; white matter necrosis occurs at fractionated doses >60 Gy. Although white matter necrosis is uncommon with modern techniques, functional deficits, including progressive impairments in memory, attention, and executive function have become important, because they have profound effects on quality of life. Preclinical studies have provided valuable insights into the pathogenesis of radiation-induced cognitive impairment. Given its central role in memory and neurogenesis, the majority of these studies have focused on the hippocampus. Irradiating pediatric and young adult rodent brains leads to several hippocampal changes including neuroinflammation and a marked reduction in neurogenesis. These data have been interpreted to suggest that shielding the hippocampus will prevent clinical radiation-induced cognitive impairment. However, this interpretation may be overly simplistic. Studies using older rodents, that more closely match the adult human brain tumor population, indicate that, unlike pediatric and young adult rats, older rats fail to show a radiation-induced decrease in neurogenesis or a loss of mature neurons. Nevertheless, older rats still exhibit cognitive impairment. This occurs in the absence of demyelination and/or white matter necrosis similar to what is observed clinically, suggesting that more subtle molecular, cellular and/or microanatomic modifications are involved in this radiation-induced brain injury. Given that radiation-induced cognitive impairment likely reflects damage to both hippocampal- and non-hippocampal-dependent domains, there is a critical need to investigate the microanatomic and functional effects of radiation in various brain regions as well as their

  1. Radiation-induced brain injury: A review

    International Nuclear Information System (INIS)

    Greene-Schloesser, Dana; Robbins, Mike E.; Peiffer, Ann M.; Shaw, Edward G.; Wheeler, Kenneth T.; Chan, Michael D.

    2012-01-01

    Approximately 100,000 primary and metastatic brain tumor patients/year in the US survive long enough (>6 months) to experience radiation-induced brain injury. Prior to 1970, the human brain was thought to be highly radioresistant; the acute CNS syndrome occurs after single doses >30 Gy; white matter necrosis occurs at fractionated doses >60 Gy. Although white matter necrosis is uncommon with modern techniques, functional deficits, including progressive impairments in memory, attention, and executive function have become important, because they have profound effects on quality of life. Preclinical studies have provided valuable insights into the pathogenesis of radiation-induced cognitive impairment. Given its central role in memory and neurogenesis, the majority of these studies have focused on the hippocampus. Irradiating pediatric and young adult rodent brains leads to several hippocampal changes including neuroinflammation and a marked reduction in neurogenesis. These data have been interpreted to suggest that shielding the hippocampus will prevent clinical radiation-induced cognitive impairment. However, this interpretation may be overly simplistic. Studies using older rodents, that more closely match the adult human brain tumor population, indicate that, unlike pediatric and young adult rats, older rats fail to show a radiation-induced decrease in neurogenesis or a loss of mature neurons. Nevertheless, older rats still exhibit cognitive impairment. This occurs in the absence of demyelination and/or white matter necrosis similar to what is observed clinically, suggesting that more subtle molecular, cellular and/or microanatomic modifications are involved in this radiation-induced brain injury. Given that radiation-induced cognitive impairment likely reflects damage to both hippocampal- and non-hippocampal-dependent domains, there is a critical need to investigate the microanatomic and functional effects of radiation in various brain regions as well as their

  2. Radiosurgery for brain metastases: is whole brain radiation therapy necessary?

    International Nuclear Information System (INIS)

    Forstner, Julie M.; Sneed, Penny K.; Lamborn, Kathleen R.; Shu, H.-K.G.; McDermott, Michael W.; Park, Elaine; Ho, Maria; Chang, Susan; Gutin, Philip H.; Phillips, Theodore L.; Wara, William M.; Larson, David A.

    1996-01-01

    , (12(33)) patients (36%) failed in the brain and (18(33)) (55%) died without evidence of brain failure. New metastases developed in (16(54)) patients treated with RS alone vs. (9(33)) patients treated with RS + WBRT (29% vs. 27%). Treated metastases progressed in (10(54)) patients who had RS alone vs. (9(33)) patients who had RS + WBRT (19% vs. 15%). Ten patients received salvage WBRT. For the 47 patients with solitary lesions, there was no significant difference in Brain FFP or survival for RS + WBRT vs. RS alone, although patients appeared to fail earlier in the RS alone group. For the 40 patients with multiple lesions, there was a definite trend toward improved Brain FFP for RS + WBRT vs. RS alone, but there was no suggestion of a survival difference. Cox multivariate analyses adjusting for known prognostic factors confirmed these findings. Conclusion: Whole brain radiation therapy may not be necessary in the initial management of patients treated with RS for brain metastases, because the omission of WBRT has limited impact on Brain FFP and does not seem to compromise survival. We attempted to adjust for important prognostic variables in this retrospective review, but there could have been a bias toward giving WBRT in patients with poorer prognosis. To eliminate bias, a randomized trial of RS vs. RS + WBRT is needed to assess survival, quality of life, and cost in selected patients with newly diagnosed brain metastases. Quality of life evaluation is needed to assess the balance between the impact of possible WBRT toxicity and possible earlier intracranial failure associated with RS alone

  3. Anatomically guided voxel-based partial volume effect correction in brain PET : Impact of MRI segmentation

    NARCIS (Netherlands)

    Gutierrez, Daniel; Montandon, Marie-Louise; Assal, Frederic; Allaoua, Mohamed; Ratib, Osman; Loevblad, Karl-Olof; Zaidi, Habib

    2012-01-01

    Partial volume effect is still considered one of the main limitations in brain PET imaging given the limited spatial resolution of current generation PET scanners. The accuracy of anatomically guided partial volume effect correction (PVC) algorithms in brain PET is largely dependent on the

  4. Radiation planning of brain tumor

    International Nuclear Information System (INIS)

    Iwata, Takeo

    1979-01-01

    Various irradiation programs in the management of lesions of the hypophyseal region were examined by computer methods. A cases of 27-year-old female with diagonal head measuring 17.5 x 15.2 cm, who has undergone partial hypophysectomy and ensuing irradiation treatment was used for compounding of isodose curves. At the start of program making, considerations were paid to the following five points. 1) to protect the eyeballs from the irradiation. 2) to reduce the irradiation doses to the normal tissue to the minimum. 3) to require no difficulty and trouble some technics for the irradiation. 4) required to avoid the special posture of patient at the irradiation procedure. 5) to avoid the use of special fixing tool for the irradiation. After various methods were applied and its fields irradiation doses were measured, 5 portal irradiation methods among multiple fixed fields irradiation methods has shown dose distribution resembling to rotating irradiation method and is considered to yield satisfactory therapeutic effects. Furthermore, the method of head fixing at the multiple fixed fields irradiation was also examined. (author)

  5. Aesthetic results following partial mastectomy and radiation therapy

    International Nuclear Information System (INIS)

    Matory, W.E. Jr.; Wertheimer, M.; Fitzgerald, T.J.; Walton, R.L.; Love, S.; Matory, W.E.

    1990-01-01

    This study was undertaken to determine the aesthetic changes inherent in partial mastectomy followed by radiation therapy in the treatment of stage I and stage II breast cancer. A retrospective analysis of breast cancer patients treated according to the National Surgical Adjuvant Breast Project Protocol B-06 was undertaken in 57 patients from 1984 to the present. The size of mastectomy varied between 2 x 1 cm and 15 x 8 cm. Objective aesthetic outcome, as determined by physical and photographic examination, was influenced primarily by surgical technique as opposed to the effects of radiation. These technical factors included orientation of resections, breast size relative to size of resection, location of tumor, and extent and orientation of axillary dissection. Regarding cosmesis, 80 percent of patients treated in this study judged their result to be excellent or good, in comparison to 50 percent excellent or good as judged by the plastic surgeon. Only 10 percent would consider mastectomy with reconstruction for contralateral disease. Asymmetry and contour abnormalities are far more common than noted in the radiation therapy literature. Patients satisfaction with lumpectomy and radiation, however, is very high. This satisfaction is not necessarily based on objective criteria defining aesthetic parameters, but is strongly influenced by retainment of the breast as an original body part

  6. Radiation effects in brain and spinal cord

    International Nuclear Information System (INIS)

    Franke, H.D.; Lierse, W.

    1978-01-01

    Radiation sensitivity of both the brain and spinal cord in prenatal and postnatal stages, in infancy and adult age is represented also in consideration of a combined treatment with methotrexate. In adults, application of important doses of high-energy radiation increases the risk of injurious effects to the central nervous system. If the spinal cord is involved, more than 60% of the radiolesions have a progredient course ending with death. The pathogenesis and disposing factors are referred to, and the incidence of radiation necrosis with regard to age and sex, the degrees of injury and their frequence within different ranges of dosage are analyzed on the basis of data from universal literature. An examination of 'tolerance doses' for the spinal cord is made by means of Strandquist-diagrams and of the Ellis-formula. The slopes of regression lines are reported for various 'degrees of response' in skin, brain and spinal cord following radiation therapy. In the Strandquist-diagram, slopes of regression lines are dependent on the 'degree of response', flattening if skin and spinal cord are affected by radiation in the same degree, necroses having the same slope for both the organs. (orig./MG) [de

  7. Radiation effect on partially synchronized Yoshida sarcoma cells

    International Nuclear Information System (INIS)

    Bippus, P.H.; Heitz, J.; Ruehl, U.; Averdunk, R.

    1982-01-01

    Yoshida sarcoma cells, which have the same growth characteristics as ascites cells in the mouse and in cell suspension, were partially synchronized in vitro by means of excess thymidine (0.1 mM thymidine for 18 h). The growth of non-synchronized cultures was inhibited by irradiation, the degree depending on the dose of radiation. At the same time, a 50% inhibition in vivo (380 rad) and in vitro (480 rad) was determined. The incorporation of 3 H-thymidine into the DNA is inhibited by 10-32%, depending on the radiation dose. The mitotic index decreases 2 h after irradiation by a dose-dependent amount. A mitotic maximum develops later; the delay is dose-dependent. Partially synchronized cells were irradiated in the G 1 /S-, S-, G 2 -, and G 1 -phase. As compared to the 3 H-thymidine incorporation and the mitotic index there were no significant differences between the cultures which were irradiated in the individual phases of the non-synchronized control cultures. The cultures which were irradiated in the G 2 -phase, however, showed a significantly reduced growth in vivo after 48 h. If the cells were cultured for more than 72 h after irradiation, the differences between the cultures irradiated in the G 2 -phase and the other phases were reduced. (orig.)

  8. Whole-brain radiation therapy for brain metastases: detrimental or beneficial?

    International Nuclear Information System (INIS)

    Gemici, Cengiz; Yaprak, Gokhan

    2015-01-01

    Stereotactic radiosurgery is frequently used, either alone or together with whole-brain radiation therapy to treat brain metastases from solid tumors. Certain experts and radiation oncology groups have proposed replacing whole-brain radiation therapy with stereotactic radiosurgery alone for the management of brain metastases. Although randomized trials have favored adding whole-brain radiation therapy to stereotactic radiosurgery for most end points, a recent meta-analysis demonstrated a survival disadvantage for patients treated with whole-brain radiation therapy and stereotactic radiosurgery compared with patients treated with stereotactic radiosurgery alone. However the apparent detrimental effect of adding whole-brain radiation therapy to stereotactic radiosurgery reported in this meta-analysis may be the result of inhomogeneous distribution of the patients with respect to tumor histologies, molecular histologic subtypes, and extracranial tumor stages between the groups rather than a real effect. Unfortunately, soon after this meta-analysis was published, even as an abstract, use of whole-brain radiation therapy in managing brain metastases has become controversial among radiation oncologists. The American Society of Radiation Oncology recently recommended, in their “Choose Wisely” campaign, against routinely adding whole-brain radiation therapy to stereotactic radiosurgery to treat brain metastases. However, this situation creates conflict for radiation oncologists who believe that there are enough high level of evidence for the effectiveness of whole-brain radiation therapy in the treatment of brain metastases

  9. Dose-Dependent Cortical Thinning After Partial Brain Irradiation in High-Grade Glioma

    Energy Technology Data Exchange (ETDEWEB)

    Karunamuni, Roshan [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Bartsch, Hauke; White, Nathan S. [Department of Radiology, University of California San Diego, La Jolla, California (United States); Moiseenko, Vitali; Carmona, Ruben; Marshall, Deborah C.; Seibert, Tyler M. [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); McDonald, Carrie R. [Department of Psychiatry, University of California San Diego, La Jolla, California (United States); Farid, Nikdokht; Krishnan, Anithapriya; Kuperman, Joshua [Department of Radiology, University of California San Diego, La Jolla, California (United States); Mell, Loren [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States); Brewer, James B.; Dale, Anders M. [Department of Radiology, University of California San Diego, La Jolla, California (United States); Hattangadi-Gluth, Jona A., E-mail: jhattangadi@ucsd.edu [Department of Radiation Medicine and Applied Sciences, University of California San Diego, La Jolla, California (United States)

    2016-02-01

    Purpose: Radiation-induced cognitive deficits may be mediated by tissue damage to cortical regions. Volumetric changes in cortex can be reliably measured using high-resolution magnetic resonance imaging (MRI). We used these methods to study the association between radiation therapy (RT) dose and change in cortical thickness in high-grade glioma (HGG) patients. Methods and Materials: We performed a voxel-wise analysis of MRI from 15 HGG patients who underwent fractionated partial brain RT. Three-dimensional MRI was acquired pre- and 1 year post RT. Cortex was parceled with well-validated segmentation software. Surgical cavities were censored. Each cortical voxel was assigned a change in cortical thickness between time points, RT dose value, and neuroanatomic label by lobe. Effects of dose, neuroanatomic location, age, and chemotherapy on cortical thickness were tested using linear mixed effects (LME) modeling. Results: Cortical atrophy was seen after 1 year post RT with greater effects at higher doses. Estimates from LME modeling showed that cortical thickness decreased by −0.0033 mm (P<.001) for every 1-Gy increase in RT dose. Temporal and limbic cortex exhibited the largest changes in cortical thickness per Gy compared to that in other regions (P<.001). Age and chemotherapy were not significantly associated with change in cortical thickness. Conclusions: We found dose-dependent thinning of the cerebral cortex, with varying neuroanatomical regional sensitivity, 1 year after fractionated partial brain RT. The magnitude of thinning parallels 1-year atrophy rates seen in neurodegenerative diseases and may contribute to cognitive decline following high-dose RT.

  10. Brain tumors and synchrotron radiation: Methodological developments in quantitative brain perfusion imaging and radiation therapy

    International Nuclear Information System (INIS)

    Adam, Jean-Francois

    2005-01-01

    High-grade gliomas are the most frequent type of primary brain tumors in adults. Unfortunately, the management of glioblastomas is still mainly palliative and remains a difficult challenge, despite advances in brain tumor molecular biology and in some emerging therapies. Synchrotron radiation opens fields for medical imaging and radiation therapy by using monochromatic intense x-ray beams. It is now well known that angiogenesis plays a critical role in the tumor growth process and that brain perfusion is representative of the tumor mitotic activity. Synchrotron radiation quantitative computed tomography (SRCT) is one of the most accurate techniques for measuring in vivo contrast agent concentration and thus computing precise and accurate absolute values of the brain perfusion key parameters. The methodological developments of SRCT absolute brain perfusion measurements as well as their preclinical validation are detailed in this thesis. In particular, absolute cerebral volume and blood brain barrier permeability high-resolution (pixel size 2 ) parametric maps were reported. In conventional radiotherapy, the treatment of these tumors remains a delicate challenge, because the damages to the surrounding normal brain tissue limit the amount of radiation that can be delivered. One strategy to overcome this limitation is to infuse an iodinated contrast agent to the patient during the irradiation. The contrast agent accumulates in the tumor, through the broken blood brain barrier, and the irradiation is performed with kilovoltage x rays, in tomography mode, the tumor being located at the center of rotation and the beam size adjusted to the tumor dimensions. The dose enhancement results from the photoelectric effect on the heavy element and from the irradiation geometry. Synchrotron beams, providing high intensity, tunable monochromatic x rays, are ideal for this treatment. The beam properties allow the selection of monochromatic irradiation, at the optimal energy, for a

  11. Radiation effects on the developing human brain

    International Nuclear Information System (INIS)

    1993-01-01

    The developing human brain has been shown to be especially sensitive to ionizing radiation. Mental retardation has been observed in the survivors of the atomic bombings in Japan exposed in utero during sensitive periods, and clinical studies of pelvically irradiated pregnant women have demonstrated damaging effects on the fetus. In this annex the emphasis is on reviewing the results of the study of the survivors of the atomic bombings in Japan, although the results of other human epidemiological investigations and of pertinent experimental studies are also considered. Refs, 3 figs, 10 tabs

  12. Subacute brain atrophy induced by radiation therapy to the malignant brain tumors

    International Nuclear Information System (INIS)

    Asai, Akio; Matsutani, Masao; Takakura, Kintomo.

    1987-01-01

    In order to analyze brain atrophy after radiation therapy to the brain tumors, we calculated a CSF-cranial volume ratio on CT scan as an index of brain atrophy, and estimated dementia-score by Hasegawa's method in 91 post-irradiated patients with malignant brain tumors. Radiation-induced brain atrophy was observed in 51 out of 91 patients (56 %) and dementia in 23 out of 47 patients (49 %). These two conditions were closely related, and observed significantly more often in aged and whole-brain-irradiated patients. As radiation-induced brain atrophy accompanied by dementia appeared 2 - 3 months after the completion of radiation therapy, it should be regarded as a subacute brain injury caused by radiation therapy. (author)

  13. Partial radiative recombination cross sections for excited states of hydrogen

    International Nuclear Information System (INIS)

    Fazio, P.M.

    1984-01-01

    In calculating the radiative recombination cross sections for interstellar H II regions, usually only the electric dipole term in the expansion of the interaction Hamiltonian is kept. The dipole and quadrupole transition strengths in closed analytical form are calculated here using the Coulomb wave functions because results for any electron energy and for recombination into any angular momentum state of hydrogen are needed. Several interesting effects are found. First, the transition probabilities are maximum for recombination into specific intermediate angular momentum states at low energies (w < 2eV) and where the free state angular momentum is greater than that of the bound state. Further, that specific intermediate angular momentum state depends on the kinetic energy of the free electron. This behavior is in contrast to the normal behavior of the transition strengths where recombination into s states is greatest and decreases with increasing angular momentum. Second, the quadrupole matrix elements vanish for certain velocities of the free electron. This leads to minima in the corresponding quadrupole cross sections when plotted as a function of the free electron's kinetic energy. Finally, the partial cross sections for highly excited states are greater than previously calculated because of the additional effects of the quadrupole transitions

  14. Partially Overlapping Brain Networks for Singing and Cello Playing

    Directory of Open Access Journals (Sweden)

    Melanie Segado

    2018-05-01

    Full Text Available This research uses an MR-Compatible cello to compare functional brain activation during singing and cello playing within the same individuals to determine the extent to which arbitrary auditory-motor associations, like those required to play the cello, co-opt functional brain networks that evolved for singing. Musical instrument playing and singing both require highly specific associations between sounds and movements. Because these are both used to produce musical sounds, it is often assumed in the literature that their neural underpinnings are highly similar. However, singing is an evolutionarily old human trait, and the auditory-motor associations used for singing are also used for speech and non-speech vocalizations. This sets it apart from the arbitrary auditory-motor associations required to play musical instruments. The pitch range of the cello is similar to that of the human voice, but cello playing is completely independent of the vocal apparatus, and can therefore be used to dissociate the auditory-vocal network from that of the auditory-motor network. While in the MR-Scanner, 11 expert cellists listened to and subsequently produced individual tones either by singing or cello playing. All participants were able to sing and play the target tones in tune (<50C deviation from target. We found that brain activity during cello playing directly overlaps with brain activity during singing in many areas within the auditory-vocal network. These include primary motor, dorsal pre-motor, and supplementary motor cortices (M1, dPMC, SMA,the primary and periprimary auditory cortices within the superior temporal gyrus (STG including Heschl's gyrus, anterior insula (aINS, anterior cingulate cortex (ACC, and intraparietal sulcus (IPS, and Cerebellum but, notably, exclude the periaqueductal gray (PAG and basal ganglia (Putamen. Second, we found that activity within the overlapping areas is positively correlated with, and therefore likely contributing to

  15. Delayed radiation injury to the brain

    International Nuclear Information System (INIS)

    Takano, Shingo; Yoshii, Yoshihiko; Okazaki, Masao; Nose, Tadao; Aida, Shinsuke

    1989-01-01

    The authors report four cases of delayed radiation injury to the brain. One case was diagnosed histologically, and the other three cases, by means of serial CT scans and clinical symptoms. In all cases, a low-density area was observed 4-15 months after radiotherapy, then the contrast-enhanced area appeared within the low-density area about 4 months later. The enhanced area was distant from the original tumor, but within the field of radiotherapy. In the relationship between CT scans and superimposed dose distributions, the enhanced area and the low-density area were always observed within a zone of more than 80% of the total doses, and, as for the irradiated doses, there was no difference between the two areas. However, a distinct difference between these two areas was noted in the MRI scans and histopathology. The enhanced area was imaged as an area of a high signal by means of Gd-DTPA enhanced T 1 -weighted images in two cases. In the one histologically verified case, the fibrinoid necrosis of the blood vessel and demyelination appeared significantly higher in the enhanced area than in the low-density area. In conclusion, when a low-density area was observed by CT scan within the field of radiotherapy, we also suspected radiation injury and considered steroid or anticoagulant therapy in order to reverse it. However, if an enhanced area appeared within the injured lesion, the area seemed to have become irreversible and surgical therapy might also be needed. (author)

  16. MDD diagnosis based on partial-brain functional connection network

    Science.gov (United States)

    Yan, Gaoliang; Hu, Hailong; Zhao, Xiang; Zhang, Lin; Qu, Zehui; Li, Yantao

    2018-04-01

    Artificial intelligence (AI) is a hotspot in computer science research nowadays. To apply AI technology in all industries has been the developing direction for researchers. Major depressive disorder (MDD) is a common disease of serious mental disorders. The World Health Organization (WHO) reports that MDD is projected to become the second most common cause of death and disability by 2020. At present, the way of MDD diagnosis is single. Applying AI technology to MDD diagnosis and pathophysiological research will speed up the MDD research and improve the efficiency of MDD diagnosis. In this study, we select the higher degree of brain network functional connectivity by statistical methods. And our experiments show that the average accuracy of Logistic Regression (LR) classifier using feature filtering reaches 88.48%. Compared with other classification methods, both the efficiency and accuracy of this method are improved, which will greatly improve the process of MDD diagnose. In these experiments, we also define the brain regions associated with MDD, which plays a vital role in MDD pathophysiological research.

  17. Partially Overlapping Brain Networks for Singing and Cello Playing.

    Science.gov (United States)

    Segado, Melanie; Hollinger, Avrum; Thibodeau, Joseph; Penhune, Virginia; Zatorre, Robert J

    2018-01-01

    This research uses an MR-Compatible cello to compare functional brain activation during singing and cello playing within the same individuals to determine the extent to which arbitrary auditory-motor associations, like those required to play the cello, co-opt functional brain networks that evolved for singing. Musical instrument playing and singing both require highly specific associations between sounds and movements. Because these are both used to produce musical sounds, it is often assumed in the literature that their neural underpinnings are highly similar. However, singing is an evolutionarily old human trait, and the auditory-motor associations used for singing are also used for speech and non-speech vocalizations. This sets it apart from the arbitrary auditory-motor associations required to play musical instruments. The pitch range of the cello is similar to that of the human voice, but cello playing is completely independent of the vocal apparatus, and can therefore be used to dissociate the auditory-vocal network from that of the auditory-motor network. While in the MR-Scanner, 11 expert cellists listened to and subsequently produced individual tones either by singing or cello playing. All participants were able to sing and play the target tones in tune (singing in many areas within the auditory-vocal network. These include primary motor, dorsal pre-motor, and supplementary motor cortices (M1, dPMC, SMA),the primary and periprimary auditory cortices within the superior temporal gyrus (STG) including Heschl's gyrus, anterior insula (aINS), anterior cingulate cortex (ACC), and intraparietal sulcus (IPS), and Cerebellum but, notably, exclude the periaqueductal gray (PAG) and basal ganglia (Putamen). Second, we found that activity within the overlapping areas is positively correlated with, and therefore likely contributing to, both singing and playing in tune determined with performance measures. Third, we found that activity in auditory areas is functionally

  18. Intensity-Modulated Radiation Therapy for Primary Brain Tumors

    Institute of Scientific and Technical Information of China (English)

    Zhong-min Wang

    2004-01-01

    Radiation therapy has been used to treat primary brain tumors as standard primary and/or adjunctive therapies for decades. It is difficult for conventional radiotherapy to deliver a lethal dose of radiation to the tumors while sparing surrounding normal brain due to complicated structures and multifunction in human brain. With the understanding of radiation physics and computer technology, a number of novel and more precise radiotherapies have been developed in recent years. Intensity modulated radiotherapy (IMRT) is one of these strategies. The use of IMRT in the treatment of primary brain tumors is being increasing nowadays. It shows great promise for some of primary brain tumors and also presents some problems, This review highlights current IMRT in the treatment of mainly primary brain tumors.

  19. Radiation effect on oligodendroglial lineage cells of brain

    International Nuclear Information System (INIS)

    Yu Dahai; Tianye

    2009-01-01

    Radiotherapy is a important treatment method for primary and metastatic cancers in the brain. How-ever, a high dose of radiation always leads to the brain injury. A representative pathological manifest of the radiation-induced brain impairment is demyelination. Therefore oligodendrocytes, the myelin-forming cells in the central nervous system, have been focused more attention recently. Oligodendrocytes originate from the migratory, mitotic progenitors and mature progressively into postmitotic myelinating cells. Recent years, a series of studies have been initiated to address the role of oligodendrocyte lineage cells in radiation-induced neurotoxic processes. This article pays attention to these studies, aiming to explore mechanisms of the radiation-induced brain impairment. (authors)

  20. Diagnosis of partial body radiation exposure in mice using peripheral blood gene expression profiles.

    Directory of Open Access Journals (Sweden)

    Sarah K Meadows

    2010-07-01

    Full Text Available In the event of a terrorist-mediated attack in the United States using radiological or improvised nuclear weapons, it is expected that hundreds of thousands of people could be exposed to life-threatening levels of ionizing radiation. We have recently shown that genome-wide expression analysis of the peripheral blood (PB can generate gene expression profiles that can predict radiation exposure and distinguish the dose level of exposure following total body irradiation (TBI. However, in the event a radiation-mass casualty scenario, many victims will have heterogeneous exposure due to partial shielding and it is unknown whether PB gene expression profiles would be useful in predicting the status of partially irradiated individuals. Here, we identified gene expression profiles in the PB that were characteristic of anterior hemibody-, posterior hemibody- and single limb-irradiation at 0.5 Gy, 2 Gy and 10 Gy in C57Bl6 mice. These PB signatures predicted the radiation status of partially irradiated mice with a high level of accuracy (range 79-100% compared to non-irradiated mice. Interestingly, PB signatures of partial body irradiation were poorly predictive of radiation status by site of injury (range 16-43%, suggesting that the PB molecular response to partial body irradiation was anatomic site specific. Importantly, PB gene signatures generated from TBI-treated mice failed completely to predict the radiation status of partially irradiated animals or non-irradiated controls. These data demonstrate that partial body irradiation, even to a single limb, generates a characteristic PB signature of radiation injury and thus may necessitate the use of multiple signatures, both partial body and total body, to accurately assess the status of an individual exposed to radiation.

  1. Radiation-induced brain structural and functional abnormalities in presymptomatic phase and outcome prediction.

    Science.gov (United States)

    Ding, Zhongxiang; Zhang, Han; Lv, Xiao-Fei; Xie, Fei; Liu, Lizhi; Qiu, Shijun; Li, Li; Shen, Dinggang

    2018-01-01

    Radiation therapy, a major method of treatment for brain cancer, may cause severe brain injuries after many years. We used a rare and unique cohort of nasopharyngeal carcinoma patients with normal-appearing brains to study possible early irradiation injury in its presymptomatic phase before severe, irreversible necrosis happens. The aim is to detect any structural or functional imaging biomarker that is sensitive to early irradiation injury, and to understand the recovery and progression of irradiation injury that can shed light on outcome prediction for early clinical intervention. We found an acute increase in local brain activity that is followed by extensive reductions in such activity in the temporal lobe and significant loss of functional connectivity in a distributed, large-scale, high-level cognitive function-related brain network. Intriguingly, these radiosensitive functional alterations were found to be fully or partially recoverable. In contrast, progressive late disruptions to the integrity of the related far-end white matter structure began to be significant after one year. Importantly, early increased local brain functional activity was predictive of severe later temporal lobe necrosis. Based on these findings, we proposed a dynamic, multifactorial model for radiation injury and another preventive model for timely clinical intervention. Hum Brain Mapp 39:407-427, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  2. Autopsy case of delayed radiation necrosis of the brain

    Energy Technology Data Exchange (ETDEWEB)

    Ihara, Katsuo; Otsutomo, Michinori; Takeshita, Gen (Aomori Rosai Hospital (Japan))

    1984-06-01

    A 48-year-old housewife underwent radiation therapy with 5,000 rad of cobalt following surgery for craniopharyngioma. One year later she developed symptoms of increased intracranial pressure, so that recurrence or occurrence of cerebral tumor was suspected. She died two years after the occurrence of the disease and was found to have had delayed radiation necrosis of the brain at autopsy.

  3. Quantitative analysis of CT brain images: a statistical model incorporating partial volume and beam hardening effects

    International Nuclear Information System (INIS)

    McLoughlin, R.F.; Ryan, M.V.; Heuston, P.M.; McCoy, C.T.; Masterson, J.B.

    1992-01-01

    The purpose of this study was to construct and evaluate a statistical model for the quantitative analysis of computed tomographic brain images. Data were derived from standard sections in 34 normal studies. A model representing the intercranial pure tissue and partial volume areas, with allowance for beam hardening, was developed. The average percentage error in estimation of areas, derived from phantom tests using the model, was 28.47%. We conclude that our model is not sufficiently accurate to be of clinical use, even though allowance was made for partial volume and beam hardening effects. (author)

  4. NMR imaging of cell phone radiation absorption in brain tissue

    Science.gov (United States)

    Gultekin, David H.; Moeller, Lothar

    2013-01-01

    A method is described for measuring absorbed electromagnetic energy radiated from cell phone antennae into ex vivo brain tissue. NMR images the 3D thermal dynamics inside ex vivo bovine brain tissue and equivalent gel under exposure to power and irradiation time-varying radio frequency (RF) fields. The absorbed RF energy in brain tissue converts into Joule heat and affects the nuclear magnetic shielding and the Larmor precession. The resultant temperature increase is measured by the resonance frequency shift of hydrogen protons in brain tissue. This proposed application of NMR thermometry offers sufficient spatial and temporal resolution to characterize the hot spots from absorbed cell phone radiation in aqueous media and biological tissues. Specific absorption rate measurements averaged over 1 mg and 10 s in the brain tissue cover the total absorption volume. Reference measurements with fiber optic temperature sensors confirm the accuracy of the NMR thermometry. PMID:23248293

  5. Partial radiative capture of resonance neutrons; Capture radiative partielle des neutrons de resonance

    Energy Technology Data Exchange (ETDEWEB)

    Samour, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    The radiative capture of resonance neutrons has been studied near the Saclay linac between 0.5 and 700 eV with time-of-flight method and a Ge(Li) detector. {sup 195}Pt + n and {sup 183}W + n allow the study of the distribution of partial radiative widths and their eventual correlation and also the variation of < {gamma}{sub {gamma}{sub i}} > with E{sub {gamma}}. The mean values of Ml and El transition intensities are compared in several tin isotopes. Interference effects, either between resonances or between direct capture and resonant capture are found in {sup 195}Pt + n, {sup 197}Au + n and {sup 59}Co + n. The excited level schemes of a great deal of nuclei are obtained and compared with theoretical predictions. This study has been completed by an analysis of thermal spectrum. (author) [French] La capture radiative des neutrons de resonance a ete etudiee pres de l'accelerateur lineaire de Saclay entre 0,5 et 700 eV a l'aide de la methode du temps-de-vol et d'un detecteur Ge(Li). Les noyaux {sup 195}Pt + n et {sup 183}W + n permettent l'analyse de la distribution de resonance en resonance des largeurs radiatives partielles {gamma}{sub {gamma}{sub i}} et de leur eventuelle correlation, ainsi que l'etude de la variation de < {gamma}{sub {gamma}{sub i}} > en fonction de E{sub {gamma}}. Les intensites moyennes des transitions Ml et El sont comparees pour quelques isotopes de l'etain. Des effets d'interference, soit entre resonances, soit entre capture directe et capture resonnante sont mis en evidence dans {sup 195}Pt + n, {sup 197}Au + n et {sup 59}Co + n. Enfin les schemas des etats excites d'un grand nombre de noyaux sont obtenus et compares avec les predictions theoriques. Cette etude a ete completee par une analyse des spectres thermiques. (auteur)

  6. Partial radiative capture of resonance neutrons; Capture radiative partielle des neutrons de resonance

    Energy Technology Data Exchange (ETDEWEB)

    Samour, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    The radiative capture of resonance neutrons has been studied near the Saclay linac between 0.5 and 700 eV with time-of-flight method and a Ge(Li) detector. {sup 195}Pt + n and {sup 183}W + n allow the study of the distribution of partial radiative widths and their eventual correlation and also the variation of < {gamma}{sub {gamma}{sub i}} > with E{sub {gamma}}. The mean values of Ml and El transition intensities are compared in several tin isotopes. Interference effects, either between resonances or between direct capture and resonant capture are found in {sup 195}Pt + n, {sup 197}Au + n and {sup 59}Co + n. The excited level schemes of a great deal of nuclei are obtained and compared with theoretical predictions. This study has been completed by an analysis of thermal spectrum. (author) [French] La capture radiative des neutrons de resonance a ete etudiee pres de l'accelerateur lineaire de Saclay entre 0,5 et 700 eV a l'aide de la methode du temps-de-vol et d'un detecteur Ge(Li). Les noyaux {sup 195}Pt + n et {sup 183}W + n permettent l'analyse de la distribution de resonance en resonance des largeurs radiatives partielles {gamma}{sub {gamma}{sub i}} et de leur eventuelle correlation, ainsi que l'etude de la variation de < {gamma}{sub {gamma}{sub i}} > en fonction de E{sub {gamma}}. Les intensites moyennes des transitions Ml et El sont comparees pour quelques isotopes de l'etain. Des effets d'interference, soit entre resonances, soit entre capture directe et capture resonnante sont mis en evidence dans {sup 195}Pt + n, {sup 197}Au + n et {sup 59}Co + n. Enfin les schemas des etats excites d'un grand nombre de noyaux sont obtenus et compares avec les predictions theoriques. Cette etude a ete completee par une analyse des spectres thermiques. (auteur)

  7. Tamoxifen with and without radiation after partial mastectomy in patients with involved nodes

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, Andrew L; Perera, Francisco; Fisher, Barbara; Opeitum, Abiola; Yu, Norman

    1995-02-15

    Purpose: To determine the effect of tamoxifen on local control after partial mastectomy with and without adjuvant breast irradiation. Methods and Materials: A retrospective study of 97 node positive patients identified from the records of the London Regional Cancer Center included 44 patients who received tamoxifen and breast irradiation (40 or 50 Gy plus booster dose) after partial mastectomy, and 53 patients who received tamoxifen only after partial mastectomy. Base line characteristics of the two groups were similar. Results: At 39 months actuarial follow-up there was a breast tumor recurrence (BTR) in 5% vs. 21% of patients when radiation was omitted (p = 0.0388), but there was no difference in the cause-specific mortality of the two treatment groups. Cox Regression analysis (on only 10 BTR) showed age and adjuvant radiation as significant predictors of BTR. In patients not receiving radiation, no BTR was seen in 22 patients {>=}70 years of age at diagnosis vs. 8 BTR in 31 patients <70 years (p = 0.0130). All BTR occurred while patients were receiving tamoxifen. Conclusion: Tamoxifen alone with omission of radiation after partial mastectomy provides inferior breast tumor control in node positive patients. This is especially true for patients under 70 years of age. Patients aged 70 years or older at the time of diagnosis of breast cancer who receive tamoxifen have a low rate of breast tumor recurrence when radiation is omitted. These patients represent a group for whom radiation might not be necessary.

  8. Effects of ionizing radiation and partial hepatectomy on messenger RNA synthesis

    International Nuclear Information System (INIS)

    Abdel-Halim, M.N.

    1979-01-01

    Newly synthesized messenger RNA, as measured by a 40 min uptake of the radioactive precursor (6- 14 C) orotic acid, was studied in the regenerating livers of non-irradiated and gamma-irradiated (1800 rad) adrenal-intact and adrenalectomized rats 24 and 48 hours after partial hepatectomy. Two groups of rats, one with and one without adrenal glands were each divided into four subgroups: (1) control rats, (2) irradiated rats, (3) partially hepatectomized rats and (4) irradiated, partially hepatectomized rats. The radioactive profile of polyribosome formation and distribution was determined by sucrose density gradient centrifugation (10 to 40 per cent). The result of this study indicates that ionizing radiation decreases the synthesis of newly formed messenger RNA in regenerating livers of adrenal-intact rats. However, adrenalectomy largely abolished that inhibition. These data suggest that the decrease in messenger RNA synthesis may be explained by the disturbance of adrenal hormones induced by partial hepatectomy and ionizing radiation. (author)

  9. Brain tissue partial pressure of oxygen predicts the outcome of severe traumatic brain injury under mild hypothermia treatment

    Directory of Open Access Journals (Sweden)

    Sun H

    2016-08-01

    Full Text Available Hongtao Sun,1,* Maohua Zheng,2,* Yanmin Wang,1 Yunfeng Diao,1 Wanyong Zhao,1 Zhengjun Wei1 1Sixth Department of Neurosurgery, Affiliated Hospital of Logistics University of People’s Armed Police Force, Tianjin, 2Department of Neurosurgery, The First Hospital of Lanzhou University, Lanzhou, People’s Republic of China *These authors contributed equally to this work Objective: The aim of this study was to investigate the clinical significance and changes of brain tissue partial pressure of oxygen (PbtO2 in the course of mild hypothermia treatment (MHT for treating severe traumatic brain injury (sTBI. Methods: There were 68 cases with sTBI undergoing MHT. PbtO2, intracranial pressure (ICP, jugular venous oxygen saturation (SjvO2, and cerebral perfusion pressure (CPP were continuously monitored, and clinical outcomes were evaluated using the Glasgow Outcome Scale score. Results: Of 68 patients with sTBI, PbtO2, SjvO2, and CPP were obviously increased, but decreased ICP level was observed throughout the MHT. PbtO2 and ICP were negatively linearly correlated, while there was a positive linear correlation between PbtO2 and SjvO2. Monitoring CPP and SjvO2 was performed under normal circumstances, and a large proportion of patients were detected with low PbtO2. Decreased PbtO2 was also found after MHT. Conclusion: Continuous PbtO2 monitoring could be introduced to evaluate the condition of regional cerebral oxygen metabolism, thereby guiding the clinical treatment and predicting the outcome. Keywords: severe traumatic brain injury, hypothermia, brain tissue partial pressure of oxygen, therapy

  10. Delayed radiation-induced necrosis of the brain stem

    International Nuclear Information System (INIS)

    Yukawa, Osamu; Kodama, Yasunori; Kyoda, Jun; Yuki, Kiyoshi; Taniguchi, Eiji; Katayama, Shoichi; Hiroi, Tadashi; Uozumi, Toru.

    1993-01-01

    A 46-year-old man had surgery for a mixed glioma of the frontotemporal lobe. Postoperatively he received 50 Gy of irradiation. Sixteen months later he developed left hemiparesis and left facial palsy. MRI revealed lesion brain stem and basal ganglia. Despite chemotherapy and an additional 50 Gy dose, the patient deteriorated. Autopsy revealed a wide spread radiation-induced necrosis in the right cerebral hemisphere, midbrain and pons. In radiation therapy, great care must be taken to protect the normal brain tissue. (author)

  11. Influence of radiation on the blood-brain barrier and optimum time of chemotherapy

    International Nuclear Information System (INIS)

    Qin, D.X.; Zheng, R.; Tang, J.; Li, J.X.; Hu, Y.H.

    1990-01-01

    A pilot study of the destructive effects of radiation on the blood-brain barrier (BBB) was made on 14 patients with localized and limited brain tumors by 99MTc-GH imaging from August 1988 to November 1989. Count/pixel data were obtained from the unirradiated, irradiated, and tumor areas before and after radiotherapy of 30-40 Gy. It was observed that the BBB in the unirradiated area outside the radiation portal was not changed and the degree of destructive effect on the BBB in the irradiated normal area was directly proportional to the radiation dose. For 30-40 Gy, the count/pixel change enhances to average 24.7% [(147.6-118.4)/118.4], and (c) the BBB in the tumor area is partially destroyed on an average of 22.1% [(206.8-169.4)/169.4] by the tumor. The radiotherapy further enhances this effect to an average of 74.7% [(206.8-118.4)/118.4]. Case 3 showed that before radiation, the degree of destructive effect on the BBB in the tumor area was 22% [(167-137)/137] higher than normal brain tissue. After a dose of 30 Gy of irradiation, it increased to 76.7% [(242-137)/137]; 8 months later it decreased to 17% [(160.3-137)/137]. It has been proven that the BBB can recover at least partially. Based on these observations, the authors believe that in the combined treatment of operated brain tumors, radiotherapy should precede chemotherapy so as to enhance the destruction of the BBB, facilitating the incorporation of drugs into the tumor. The dose at which to start chemotherapy is 20-30 Gy

  12. An autopsy case of delayed radiation necrosis of the brain

    International Nuclear Information System (INIS)

    Ihara, Katsuo; Otsutomo, Michinori; Takeshita, Gen

    1984-01-01

    A 48-year-old housewife underwent radiation therapy with 5,000 rad of cobalt following surgery for craniopharyngioma. One year later she developed symptoms of increased intracranial pressure, so that recurrence or occurrence of cerebral tumor was suspected. She died two years after the occurrence of the disease and was found to have had delayed radiation necrosis of the brain at autopsy. (Namekawa, K.)

  13. Accelerated regression of brain metastases in patients receiving whole brain radiation and the topoisomerase II inhibitor, lucanthone

    International Nuclear Information System (INIS)

    Rowe, John D. del; Bello, Jacqueline; Mitnick, Robin; Sood, Brij; Filippi, Christopher; Moran, Justin Ph.D.; Freeman, Katherine; Mendez, Frances; Bases, Robert

    1999-01-01

    Purpose: To determine if lucanthone crossed the blood-brain barrier in experimental animals; and to determine accelerated tumor regression of human brain metastases treated jointly with lucanthone and whole brain radiation. Methods and Materials: The organ distribution of 3 H lucanthone in mice and 125 I lucanthone in rats was determined to learn if lucanthone crossed the blood-brain barrier. Size determinations were made of patients' brain metastases from magnetic resonance images or by computed tomography before and after treatment with 30 Gy whole brain radiation alone or with lucanthone. Results: The time course of lucanthone's distribution in brain was identical to that in muscle and heart after intraperitoneal or intravenous administration in experimental animals. Lucanthone, therefore, readily crossed the blood-brain barrier in experimental animals. Conclusion: Compared with radiation alone, the tumor regression in patients with brain metastases treated with lucanthone and radiation was accelerated, approaching significance using a permutation test at p = 0.0536

  14. Radiation exposure of the gonads in infant brain computerized tomography

    International Nuclear Information System (INIS)

    Berndt, L.; Rosenkranz, G.; Tellkamp, H.

    1988-01-01

    In 61 babies and infants the gonadal dose due to brain computerized tomography was determined over the symphysis by thermoluminescent dosimetry. The average radiation dose was 43 mGy corresponding with data reported. Shielding of the testes in infants is an additional burden and worth discussing because of the low absolute gonadal dose

  15. Hierarchical ordering with partial pairwise hierarchical relationships on the macaque brain data sets.

    Directory of Open Access Journals (Sweden)

    Woosang Lim

    Full Text Available Hierarchical organizations of information processing in the brain networks have been known to exist and widely studied. To find proper hierarchical structures in the macaque brain, the traditional methods need the entire pairwise hierarchical relationships between cortical areas. In this paper, we present a new method that discovers hierarchical structures of macaque brain networks by using partial information of pairwise hierarchical relationships. Our method uses a graph-based manifold learning to exploit inherent relationship, and computes pseudo distances of hierarchical levels for every pair of cortical areas. Then, we compute hierarchy levels of all cortical areas by minimizing the sum of squared hierarchical distance errors with the hierarchical information of few cortical areas. We evaluate our method on the macaque brain data sets whose true hierarchical levels are known as the FV91 model. The experimental results show that hierarchy levels computed by our method are similar to the FV91 model, and its errors are much smaller than the errors of hierarchical clustering approaches.

  16. Changes in oxygen partial pressure of brain tissue in an animal model of obstructive apnea

    Directory of Open Access Journals (Sweden)

    Torres Marta

    2010-01-01

    Full Text Available Abstract Background Cognitive impairment is one of the main consequences of obstructive sleep apnea (OSA and is usually attributed in part to the oxidative stress caused by intermittent hypoxia in cerebral tissues. The presence of oxygen-reactive species in the brain tissue should be produced by the deoxygenation-reoxygenation cycles which occur at tissue level during recurrent apneic events. However, how changes in arterial blood oxygen saturation (SpO2 during repetitive apneas translate into oxygen partial pressure (PtO2 in brain tissue has not been studied. The objective of this study was to assess whether brain tissue is partially protected from intermittently occurring interruption of O2 supply during recurrent swings in arterial SpO2 in an animal model of OSA. Methods Twenty-four male Sprague-Dawley rats (300-350 g were used. Sixteen rats were anesthetized and non-invasively subjected to recurrent obstructive apneas: 60 apneas/h, 15 s each, for 1 h. A control group of 8 rats was instrumented but not subjected to obstructive apneas. PtO2 in the cerebral cortex was measured using a fast-response oxygen microelectrode. SpO2 was measured by pulse oximetry. The time dependence of arterial SpO2 and brain tissue PtO2 was carried out by Friedman repeated measures ANOVA. Results Arterial SpO2 showed a stable periodic pattern (no significant changes in maximum [95.5 ± 0.5%; m ± SE] and minimum values [83.9 ± 1.3%]. By contrast, brain tissue PtO2 exhibited a different pattern from that of arterial SpO2. The minimum cerebral cortex PtO2 computed during the first apnea (29.6 ± 2.4 mmHg was significantly lower than baseline PtO2 (39.7 ± 2.9 mmHg; p = 0.011. In contrast to SpO2, the minimum and maximum values of PtO2 gradually increased (p 2 were significantly greater relative to baseline and the first apnea dip, respectively. Conclusions These data suggest that the cerebral cortex is partially protected from intermittently occurring interruption of

  17. Radiation treatment of brain tumors: Concepts and strategies

    International Nuclear Information System (INIS)

    Marks, J.E.

    1989-01-01

    Ionizing radiation has demonstrated clinical value for a multitude of CNS tumors. Application of the different physical modalities available has made it possible for the radiotherapist to concentrate the radiation in the region of the tumor with relative sparing of the surrounding normal tissues. Correlation of radiation dose with effect on cranial soft tissues, normal brain, and tumor has shown increasing effect with increasing dose. By using different physical modalities to alter the distribution of radiation dose, it is possible to increase the dose to the tumor and reduce the dose to the normal tissues. Alteration of the volume irradiated and the dose delivered to cranial soft tissues, normal brain, and tumor are strategies that have been effective in improving survival and decreasing complications. The quest for therapeutic gain using hyperbaric oxygen, neutrons, radiation sensitizers, chemotherapeutic agents, and BNCT has met with limited success. Both neoplastic and normal cells are affected simultaneously by all modalities of treatment, including ionizing radiation. Consequently, one is unable to totally depopulate a tumor without irreversibly damaging the normal tissues. In the case of radiation, it is the brain that limits delivery of curative doses, and in the case of chemical additives, it is other organ systems, such as bone marrow, liver, lung, kidneys, and peripheral nerves. Thus, the major obstacle in the treatment of malignant gliomas is our inability to preferentially affect the tumor with the modalities available. Until it is possible to directly target the neoplastic cell without affecting so many of the adjacent normal cells, the quest for therapeutic gain will go unrealized.72 references

  18. Partial coherence and imperfect optics at a synchrotron radiation source modeled by wavefront propagation

    Science.gov (United States)

    Laundy, David; Alcock, Simon G.; Alianelli, Lucia; Sutter, John P.; Sawhney, Kawal J. S.; Chubar, Oleg

    2014-09-01

    A full wave propagation of X-rays from source to sample at a storage ring beamline requires simulation of the electron beam source and optical elements in the beamline. The finite emittance source causes the appearance of partial coherence in the wave field. Consequently, the wavefront cannot be treated exactly with fully coherent wave propagation or fully incoherent ray tracing. We have used the wavefront code Synchrotron Radiation Workshop (SRW) to perform partially coherent wavefront propagation using a parallel computing cluster at the Diamond Light Source. Measured mirror profiles have been used to correct the wavefront for surface errors.

  19. Brain tissue partial pressure of oxygen predicts the outcome of severe traumatic brain injury under mild hypothermia treatment.

    Science.gov (United States)

    Sun, Hongtao; Zheng, Maohua; Wang, Yanmin; Diao, Yunfeng; Zhao, Wanyong; Wei, Zhengjun

    2016-01-01

    The aim of this study was to investigate the clinical significance and changes of brain tissue partial pressure of oxygen (PbtO2) in the course of mild hypothermia treatment (MHT) for treating severe traumatic brain injury (sTBI). There were 68 cases with sTBI undergoing MHT. PbtO2, intracranial pressure (ICP), jugular venous oxygen saturation (SjvO2), and cerebral perfusion pressure (CPP) were continuously monitored, and clinical outcomes were evaluated using the Glasgow Outcome Scale score. Of 68 patients with sTBI, PbtO2, SjvO2, and CPP were obviously increased, but decreased ICP level was observed throughout the MHT. PbtO2 and ICP were negatively linearly correlated, while there was a positive linear correlation between PbtO2 and SjvO2. Monitoring CPP and SjvO2 was performed under normal circumstances, and a large proportion of patients were detected with low PbtO2. Decreased PbtO2 was also found after MHT. Continuous PbtO2 monitoring could be introduced to evaluate the condition of regional cerebral oxygen metabolism, thereby guiding the clinical treatment and predicting the outcome.

  20. An improved approach to reduce partial volume errors in brain SPET

    International Nuclear Information System (INIS)

    Hatton, R.L.; Hatton, B.F.; Michael, G.; Barnden, L.; QUT, Brisbane, QLD; The Queen Elizabeth Hospital, Adelaide, SA

    1999-01-01

    Full text: Limitations in SPET resolution give rise to significant partial volume error (PVE) in small brain structures We have investigated a previously published method (Muller-Gartner et al., J Cereb Blood Flow Metab 1992;16: 650-658) to correct PVE in grey matter using MRI. An MRI is registered and segmented to obtain a grey matter tissue volume which is then smoothed to obtain resolution matched to the corresponding SPET. By dividing the original SPET with this correction map, structures can be corrected for PVE on a pixel-by-pixel basis. Since this approach is limited by space-invariant filtering, modification was made by estimating projections for the segmented MRI and reconstructing these using identical parameters to SPET. The methods were tested on simulated brain scans, reconstructed with the ordered subsets EM algorithm (8,16, 32, 64 equivalent EM iterations) The new method provided better recovery visually. For 32 EM iterations, recovery coefficients were calculated for grey matter regions. The effects of potential errors in the method were examined. Mean recovery was unchanged with one pixel registration error, the maximum error found in most registration programs. Errors in segmentation > 2 pixels results in loss of accuracy for small structures. The method promises to be useful for reducing PVE in brain SPET

  1. Stimulation of phosphoinositide hydrolysis by a novel substance partially purified from rat and bovine brain

    International Nuclear Information System (INIS)

    Schoepp, D.; Wilson, T.; Elliott, C.; Wright, G.; McCumbee, W.

    1986-01-01

    This study demonstrates the partial purification of a potentially novel substance from rat and bovine brain. Whole brains were homogenized in distilled water, then heated at 100 0 C for 30 min. The water extract was dialyzed and the 3 H-inositol monophosphate ( 3 H-IP) using lithium-treated slices of rat cerebral cortex prelabelled with 3 H-myo-inositol. A major peak of activity was observed in fractions from the molecular weight range of 800-1300 daltons. Stimulation of phosphoinositide hydrolysis by this material was time-dependent and dose-related. Maximal stimulation of 3 H-IP (323% of control) required 10mg/ml of bovine material and was observed at 30 minutes. These effects could not be mimicked by a number of substances of similar molecular weight (e.g. substance P, neurotensin, angiotensin II, bradykinin). Furthermore, the effects of this material were not blocked by antagonist drugs which act at the alpha-adrenoceptor, muscarinic cholinoceptor, 5-HT2 receptor, substance P receptor, or neurotensin receptor. These results indicate that the substance isolated may be a novel neuroactive molecule which has receptors coupled to phosphoinositide hydrolysis in brain

  2. Radiation recall secondary to adjuvant docetaxel after balloon-catheter based accelerated partial breast irradiation

    International Nuclear Information System (INIS)

    Wong, Nathan W.; Wong, William W.; Karlin, Nina J.; Gray, Richard J.

    2010-01-01

    For early stage breast cancer, wide local excision and post-operative whole breast irradiation is a standard treatment. If adjuvant chemotherapy is recommended, radiation is usually given after completion of chemotherapy. In recent years, accelerated partial breast irradiation (APBI) with balloon-cathetered based brachytherapy has become an option for selected patients. For these patients, adjuvant chemotherapy would have to be administered after radiation. The sequence of treatment with radiation followed by chemotherapy results in increased risk of radiation recall reaction (RRD) in these patients. Docetaxel is becoming a more commonly used drug as adjuvant treatment for breast cancer. Here we report a case of docetaxel induced RRD after APBI with balloon-cathetered based brachytherapy. Such reaction would have an adverse impact on the cosmetic outcome and quality of life of the patient. For patients who develop an intense skin reaction after the administration of docetaxel following APBI, RRD should be considered in the differential diagnosis.

  3. Radiation therapy of 9L rat brain tumors

    International Nuclear Information System (INIS)

    Henderson, S.D.; Kimler, B.F.; Morantz, R.A.

    1981-01-01

    The effects of radiation therapy on normal rats and on rats burdened with 9L brain tumors have been studied. The heads of normal rats were x-irradiated with single exposures ranging from 1000 R to 2700 R. Following acute exposures greater than 2100 R, all animals died in 8 to 12 days. Approximately 30% of the animals survived beyond 12 days over the range of 1850 to 1950 R; following exposures less than 1850 R, all animals survived the acute radiation effects, and median survival times increased with decreasing exposure. Three fractionated radiation schedules were also studied: 2100 R or 3000 R in 10 equal fractions, and 3000 R in 6 equal fractions, each schedule being administered over a 2 week period. The first schedule produced a MST of greater than 1 1/2 years; the other schedules produced MSTs that were lower. It was determined that by applying a factor of 1.9, similar survival responses of normal rats were obtained with single as with fractionated radiation exposures. Animals burdened with 9L gliosarcoma brain tumors normally died of the disease process within 18 to 28 days ater tumor inoculation. Both single and fractionated radiation therapy resulted in a prolongation of survival of tumor-burdened rats. This prolongation was found to be linearly dependent upon the dose; but only minimally dependent upon the time after inoculation at which therapy was initiated, or upon the fractionation schedule that was used. As with normal animals, similar responses were obtained with single as with fractionated exposures when a factor (1.9) was applied. All tumor-bearing animals died prior to the time that death was observed in normal, irradiated rats. Thus, the 9L gliosarcoma rat brain tumor model can be used for the pre-clinical experimental investigation of new therapeutic schedules involving radiation therapy and adjuvant therapies

  4. Diagnosis and treatment of cognitive deficits caused by radiation in patients with brain tumours

    International Nuclear Information System (INIS)

    Ishiuchi, Shogo

    2011-01-01

    This paper discusses about the diagnosis and evaluation of brain higher functions, feature of their impairment induced by radiotherapy for brain tumor, and association of the impairment and neurogenesis in hippocampus (H). Radiation is one of important causes of cognitive impairment in patients with brain tumor: exempli gratia (e.g.) single irradiation of 2 Gy increases its risk. The impairment is usually diagnosed and evaluated with neuropsychological tests like mini-mental state examination (MMSE), authors' Ryudai version of the brief neuropsychological test battery, etc. The neurotoxicity of radiation is classified in acute effect caused by destruction of the blood brain barrier (BBB) appearing within 2 weeks after irradiation, early-late one of demyelination as a result of BBB rupture within 1-6 months after radiotherapy and late-late effect accompanying serious symptoms like necrosis of irradiated region at later than a few months to several years. Lowered neurogenic function in H and invasion of microglia cells are observed in autopsy specimen of the irradiated brain, and single X-irradiation at 5 or 10 Gy is known to result in the arrest of neurogenesis in the mouse H dentate gyrus. Lowered cognition by irradiation of H in clinical cases is particularly reported in children. Inflammatory biomarkers like cytokines are detected in the serum of irradiated patients as well as of animals. Although fMRI alone is not satisfactory to diagnose and evaluate the radiation-induced impairment, the imaging reveals the association of anatomically different regions in cognition through neural network. It has been recently shown that the impairment can be partially protected by planning the irradiation field so as to avoid H, by medication with donepezil, memantine, erythropoietin and indomethacin, and by hyperbaric oxygen therapy. (T.T.)

  5. Effect of bevacizumab on radiation necrosis of the brain

    International Nuclear Information System (INIS)

    Gonzalez, Javier; Kumar, Ashok J.; Conrad, Charles A.; Levin, Victor A.

    2007-01-01

    Purpose: Because blocking vascular endothelial growth factor (VEGF) from reaching leaky capillaries is a logical strategy for the treatment of radiation necrosis, we reasoned that bevacizumab might be an effective treatment of radiation necrosis. Patients and Methods: Fifteen patients with malignant brain tumors were treated with bevacizumab or bevacizumab combination for their tumor on either a 5 mg/kg/2-week or 7.5 mg/kg/3-week schedule. Radiation necrosis was diagnosed in 8 of these patients on the basis of magnetic resonance imaging (MRI) and biopsy. MRI studies were obtained before treatment and at 6-week to 8-week intervals. Results: Of the 8 patients with radiation necrosis, posttreatment MRI performed an average of 8.1 weeks after the start of bevacizumab therapy showed a reduction in all 8 patients in both the MRI fluid-attenuated inversion-recovery (FLAIR) abnormalities and T1-weighted post-Gd-contrast abnormalities. The average area change in the T1-weighted post-Gd-contrast abnormalities was 48% (±22 SD), and the average change in the FLAIR images was 60% (±18 SD). The average reduction in daily dexamethasone requirements was 8.6 mg (±3.6). Conclusion: Bevacizumab, alone and in combination with other agents, can reduce radiation necrosis by decreasing capillary leakage and the associated brain edema. Our findings will need to be confirmed in a randomized trial to determine the optimal duration of treatment

  6. Technological progress in radiation therapy for brain tumors

    LENUS (Irish Health Repository)

    Vernimmen, Frederik Jozef

    2014-01-01

    To achieve a good therapeutic ratio the radiation dose to the tumor should be as high as possible with the lowest possible dose to the surrounding normal tissue. This is especially the case for brain tumors. Technological ad- vancements in diagnostic imaging, dose calculations, and radiation delivery systems, combined with a better un- derstanding of the pathophysiology of brain tumors have led to improvements in the therapeutic results. The widely used technology of delivering 3-D conformal therapy with photon beams (gamma rays) produced by Li-near Accelerators has progressed into the use of Intensity modulated radiation therapy (IMRT). Particle beams have been used for several decades for radiotherapy because of their favorable depth dose characteristics. The introduction of clinically dedicated proton beam therapy facilities has improved the access for cancer patients to this treatment. Proton therapy is of particular interest for pediatric malignancies. These technical improvements are further enhanced by the evolution in tumor physiology imaging which allows for improved delineation of the tumor. This in turn opens the potential to adjust the radiation dose to maximize the radiobiological effects. The advances in both imaging and radiation therapy delivery will be discussed.

  7. Preoperative Single-Fraction Partial Breast Radiation Therapy: A Novel Phase 1, Dose-Escalation Protocol With Radiation Response Biomarkers

    International Nuclear Information System (INIS)

    Horton, Janet K.; Blitzblau, Rachel C.; Yoo, Sua; Geradts, Joseph; Chang, Zheng; Baker, Jay A.; Georgiade, Gregory S.; Chen, Wei; Siamakpour-Reihani, Sharareh; Wang, Chunhao; Broadwater, Gloria; Groth, Jeff; Palta, Manisha; Dewhirst, Mark; Barry, William T.; Duffy, Eileen A.

    2015-01-01

    Purpose: Women with biologically favorable early-stage breast cancer are increasingly treated with accelerated partial breast radiation (PBI). However, treatment-related morbidities have been linked to the large postoperative treatment volumes required for external beam PBI. Relative to external beam delivery, alternative PBI techniques require equipment that is not universally available. To address these issues, we designed a phase 1 trial utilizing widely available technology to 1) evaluate the safety of a single radiation treatment delivered preoperatively to the small-volume, intact breast tumor and 2) identify imaging and genomic markers of radiation response. Methods and Materials: Women aged ≥55 years with clinically node-negative, estrogen receptor–positive, and/or progesterone receptor–positive HER2−, T1 invasive carcinomas, or low- to intermediate-grade in situ disease ≤2 cm were enrolled (n=32). Intensity modulated radiation therapy was used to deliver 15 Gy (n=8), 18 Gy (n=8), or 21 Gy (n=16) to the tumor with a 1.5-cm margin. Lumpectomy was performed within 10 days. Paired pre- and postradiation magnetic resonance images and patient tumor samples were analyzed. Results: No dose-limiting toxicity was observed. At a median follow-up of 23 months, there have been no recurrences. Physician-rated cosmetic outcomes were good/excellent, and chronic toxicities were grade 1 to 2 (fibrosis, hyperpigmentation) in patients receiving preoperative radiation only. Evidence of dose-dependent changes in vascular permeability, cell density, and expression of genes regulating immunity and cell death were seen in response to radiation. Conclusions: Preoperative single-dose radiation therapy to intact breast tumors is well tolerated. Radiation response is marked by early indicators of cell death in this biologically favorable patient cohort. This study represents a first step toward a novel partial breast radiation approach. Preoperative radiation should

  8. Preoperative Single-Fraction Partial Breast Radiation Therapy: A Novel Phase 1, Dose-Escalation Protocol With Radiation Response Biomarkers

    Energy Technology Data Exchange (ETDEWEB)

    Horton, Janet K., E-mail: janet.horton@duke.edu [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Blitzblau, Rachel C.; Yoo, Sua [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Geradts, Joseph [Department of Pathology, Duke University Medical Center, Durham, North Carolina (United States); Chang, Zheng [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Baker, Jay A. [Department of Radiology, Duke University Medical Center, Durham, North Carolina (United States); Georgiade, Gregory S. [Department of Surgery, Duke University Medical Center, Durham, North Carolina (United States); Chen, Wei [Department of Bioinformatics: Duke Cancer Institute, Duke University Medical Center, Durham, North Carolina (United States); Siamakpour-Reihani, Sharareh; Wang, Chunhao [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Broadwater, Gloria [Department of Biostatistics: Duke Cancer Institute, Duke University Medical Center, Durham, North Carolina (United States); Groth, Jeff [Department of Pathology, Duke University Medical Center, Durham, North Carolina (United States); Palta, Manisha; Dewhirst, Mark [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Barry, William T. [Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, North Carolina (United States); Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Duffy, Eileen A. [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); and others

    2015-07-15

    Purpose: Women with biologically favorable early-stage breast cancer are increasingly treated with accelerated partial breast radiation (PBI). However, treatment-related morbidities have been linked to the large postoperative treatment volumes required for external beam PBI. Relative to external beam delivery, alternative PBI techniques require equipment that is not universally available. To address these issues, we designed a phase 1 trial utilizing widely available technology to 1) evaluate the safety of a single radiation treatment delivered preoperatively to the small-volume, intact breast tumor and 2) identify imaging and genomic markers of radiation response. Methods and Materials: Women aged ≥55 years with clinically node-negative, estrogen receptor–positive, and/or progesterone receptor–positive HER2−, T1 invasive carcinomas, or low- to intermediate-grade in situ disease ≤2 cm were enrolled (n=32). Intensity modulated radiation therapy was used to deliver 15 Gy (n=8), 18 Gy (n=8), or 21 Gy (n=16) to the tumor with a 1.5-cm margin. Lumpectomy was performed within 10 days. Paired pre- and postradiation magnetic resonance images and patient tumor samples were analyzed. Results: No dose-limiting toxicity was observed. At a median follow-up of 23 months, there have been no recurrences. Physician-rated cosmetic outcomes were good/excellent, and chronic toxicities were grade 1 to 2 (fibrosis, hyperpigmentation) in patients receiving preoperative radiation only. Evidence of dose-dependent changes in vascular permeability, cell density, and expression of genes regulating immunity and cell death were seen in response to radiation. Conclusions: Preoperative single-dose radiation therapy to intact breast tumors is well tolerated. Radiation response is marked by early indicators of cell death in this biologically favorable patient cohort. This study represents a first step toward a novel partial breast radiation approach. Preoperative radiation should

  9. Self-Reported Cognitive Outcomes in Patients With Brain Metastases Before and After Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Cole, Ansa Maer [Department of Radiation Oncology, Medical School Hannover, Hannover (Germany); Scherwath, Angela [Department of Medical Psychology, University Medical Centre Hamburg-Eppendorf, Hamburg (Germany); Ernst, Gundula [Department of Medical Psychology, Medical School Hannover, Hannover (Germany); Lanfermann, Heinrich [Institute for Neuroradiology, Medical School Hannover, Hannover (Germany); Bremer, Michael [Department of Radiation Oncology, Medical School Hannover, Hannover (Germany); Steinmann, Diana, E-mail: steinmann.diana@mh-hannover.de [Department of Radiation Oncology, Medical School Hannover, Hannover (Germany)

    2013-11-15

    Purpose: Patients with brain metastases may experience treatment-related cognitive deficits. In this study, we prospectively assessed the self-reported cognitive abilities of patients with brain metastases from any solid primary cancer before and after irradiation of the brain. Methods and Materials: The treatment group (TG) consisted of adult patients (n=50) with brain metastases who received whole or partial irradiation of the brain without having received prior radiation therapy (RT). The control group (CG) consisted of breast cancer patients (n=27) without cranial involvement who were treated with adjuvant RT. Patients were recruited between May 2008 and December 2010. Self-reported cognitive abilities were acquired before RT and 6 weeks, 3 months, and 6 months after irradiation. The information regarding the neurocognitive status was collected by use of the German questionnaires for self-perceived deficits in attention (FEDA) and subjectively experienced everyday memory performance (FEAG). Results: The baseline data showed a high proportion of self-perceived neurocognitive deficits in both groups. A comparison between the TG and the CG regarding the course of self-reported outcomes after RT showed significant between-group differences for the FEDA scales 2 and 3: fatigue and retardation of daily living activities (P=.002) and decrease in motivation (P=.032) with an increase of attention deficits in the TG, but not in the CG. There was a trend towards significance in FEDA scale 1: distractibility and retardation of mental processes (P=.059) between the TG and the CG. The FEAG assessment presented no significant differences. An additional subgroup analysis within the TG was carried out. FEDA scale 3 showed significant differences in the time-related progress between patients with whole-brain RT and those receiving hypofractionated stereotactic RT (P=.025), with less decrease in motivation in the latter group. Conclusion: Self-reported attention declined in

  10. Self-Reported Cognitive Outcomes in Patients With Brain Metastases Before and After Radiation Therapy

    International Nuclear Information System (INIS)

    Cole, Ansa Maer; Scherwath, Angela; Ernst, Gundula; Lanfermann, Heinrich; Bremer, Michael; Steinmann, Diana

    2013-01-01

    Purpose: Patients with brain metastases may experience treatment-related cognitive deficits. In this study, we prospectively assessed the self-reported cognitive abilities of patients with brain metastases from any solid primary cancer before and after irradiation of the brain. Methods and Materials: The treatment group (TG) consisted of adult patients (n=50) with brain metastases who received whole or partial irradiation of the brain without having received prior radiation therapy (RT). The control group (CG) consisted of breast cancer patients (n=27) without cranial involvement who were treated with adjuvant RT. Patients were recruited between May 2008 and December 2010. Self-reported cognitive abilities were acquired before RT and 6 weeks, 3 months, and 6 months after irradiation. The information regarding the neurocognitive status was collected by use of the German questionnaires for self-perceived deficits in attention (FEDA) and subjectively experienced everyday memory performance (FEAG). Results: The baseline data showed a high proportion of self-perceived neurocognitive deficits in both groups. A comparison between the TG and the CG regarding the course of self-reported outcomes after RT showed significant between-group differences for the FEDA scales 2 and 3: fatigue and retardation of daily living activities (P=.002) and decrease in motivation (P=.032) with an increase of attention deficits in the TG, but not in the CG. There was a trend towards significance in FEDA scale 1: distractibility and retardation of mental processes (P=.059) between the TG and the CG. The FEAG assessment presented no significant differences. An additional subgroup analysis within the TG was carried out. FEDA scale 3 showed significant differences in the time-related progress between patients with whole-brain RT and those receiving hypofractionated stereotactic RT (P=.025), with less decrease in motivation in the latter group. Conclusion: Self-reported attention declined in

  11. Result of radiation therapy of sino-nasal cancers using partial attenuation filter

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Hee; Kim, Ok Bae; Choi, Tae Jin [Keimyung University College of Medicine, Daegu (Korea, Republic of)

    2007-06-15

    This study was to evaluate the survival and pattern of failure after radiation therapy of sino-nasal cancer using partial attenuation filer and wedged beams and to help radiotherapy planning of sino-nasal cancer. Between February 1992 and March 2003, 17 patients with sino-nasal cancers underwent radiation therapy using partial attenuation filter at Dongsan Medical Center, Keimyung university. There were 9 male and 8 female patients. Patients' age ranged from 40 to 75 years (median 59 years). There were 10 patients of maxillary sinus cancer, 7 patients of nasal cancer. The histologic type was squamous cell carcinoma in 11, adenoid cystic carcinoma in 4 and olfactory neuroblastoma in 2. The distribution of clinical stage by the AJCC system was 3 for stage II, 7 for III and 6 for IV. The five patients were treated with radiation alone and 12 patients were treated with surgery and postoperative radiation therapy. The range of total radiation dose delivered to the primary tumor was from 44 to 76 Gy (median 60 Gy). The follow-up period ranged from 3 to 173 months with median of 78 months. The overall 2 year survival rate and disease free survival rate was 76.4%. The 5 year and 10 year survival rate were 76.4% and 45.6% and the 5 year and 10 year disease free survival rate was 70.6%. The 5 year disease free survival rate by treatment modality was 91.6% for postoperative radiation group and 20% for radiation alone group, statistical significance was found by treatment modality ({rho} = 0.006). There were no differences in survival by pathology and stage. There were local failure in 5 patients (29%) but no distant failure and no severe complication required surgical intervention. Radiation therapy of sino-nasal cancer using partial attenuation filter was safe and effective. Combined modality with conservative surgery and radiation therapy was more advisable to achieve loco-regional control in sino-nasal cancer. Also we considered high precision radiation therapy with

  12. Imaging of rare radiation injuries after radiosurgery for brain metastases

    International Nuclear Information System (INIS)

    Yamanaka, Kazuhiro; Yoshimura, Masaki; Iwai, Yoshiyasu

    2011-01-01

    Gamma knife radiosurgery (GKS) is generally an effective and safe treatment for brain metastases. We report 3 rare complicated cases after GKS due to radiation injury including image findings. Case 1: A 58-year-old man received whole brain radiation therapy for right occipital brain metastasis from lung cancer. However, local recurrence was noted and GKS was carried out 5 months later (size 28 mm, marginal dose 23 Gy (50% isodose)). Four years later, a cyst appeared and the patient developed apraxia and visual disturbance. Surgery was performed and the histopathology showed necrosis. Case 2: A 51-year-old woman received GKS for 4 brain metastases from breast cancer. The right occipital lobe lesion was treated with marginal dose of 18 Gy (size 24 mm, 50% isodose). Thirty-one months later, she developed left homonymous hemianopsia and MR imaging and CT scan showed intracerebral hemorrhage with cyst formation. An operation was performed and the histology revealed necrosis. Case 3: A 37-year-old man received GKS for left temporal brain metastasis from lung cancer (size 14 mm, marginal dose 23 Gy (50% isodose)). Twelve months later, the lesion increased in size again, so we carried out a second GKS on the same lesion (size 15 mm, marginal dose 23 Gy (50% isodose)). Thirty-five months later, massive peritumoral edema appeared and the patient developed left oculomotor palsy. An emergency operation was performed and the histopathological diagnosis was cavernous malformation that was thought to be induced by radiosurgery. Although the incidence is low, rare complications associated with radiation therapy can also occur by radiosurgery. (author)

  13. Radiation-induced apoptosis and developmental disturbance of the brain

    Energy Technology Data Exchange (ETDEWEB)

    Inouye, Minoru [Nagoya Univ. (Japan). Research Inst. of Environmental Medicine

    1995-03-01

    The developing mammalian brain is highly susceptible to ionizing radiation. A significant increase in small head size and mental retardation has been noted in prenatally exposed survivors of the atomic bombing, with the highest risk in those exposed during 8-15 weeks after fertilization. This stage corresponds to day 13 of pregnancy for mice and day 15 for rats in terms of brain development. The initial damage produced by radiation at this stage is cell death in the ventricular zone (VZ) of the brain mantle, the radiosensitive germinal cell population. During histogenesis of the cerebellum the external granular layer (EGL) is also radiosensitive. Although extensive cell death results in microcephaly and histological abnormlity, both VZ and EGL have an ability to recover from a considerable cell loss and form the normal structure of the central nervous system. The number of cell deaths to induce tissue abnormalities in adult brain rises in the range of 15-25% of the germinal cell population; and the threshold doses are about 0.3 Gy for cerebral defects and 1 Gy for cerebellar anomalies in both mice and rats. A similar threshold level is suggested in human cases in induction of mental retardation. Radiation-induced cell death in the VZ and EGL has been revealed as apoptosis, by the nuclear and cytoplasmic condensation, transglutaminase activation, required macromolecular synthesis, and internucleosomal DNA cleavage. Apoptosis of the germinal cell is assumed to eliminate acquired genetic damage. Once an abnormality in DNA has been induced and fixed in a germinal cell, it would be greatly amplified during future proliferation. These cells would commit suicide when injured for replacement by healthy cells, rather than undertake DNA repair. In fact they show very slow repair of cellular damage. Thus the high sensitivity of undifferentiated neural cells to the lethal effect of radiation may constitute a biological defense mechanism. (author) 69 refs.

  14. Radiation-induced apoptosis and developmental disturbance of the brain

    International Nuclear Information System (INIS)

    Inouye, Minoru

    1995-01-01

    The developing mammalian brain is highly susceptible to ionizing radiation. A significant increase in small head size and mental retardation has been noted in prenatally exposed survivors of the atomic bombing, with the highest risk in those exposed during 8-15 weeks after fertilization. This stage corresponds to day 13 of pregnancy for mice and day 15 for rats in terms of brain development. The initial damage produced by radiation at this stage is cell death in the ventricular zone (VZ) of the brain mantle, the radiosensitive germinal cell population. During histogenesis of the cerebellum the external granular layer (EGL) is also radiosensitive. Although extensive cell death results in microcephaly and histological abnormlity, both VZ and EGL have an ability to recover from a considerable cell loss and form the normal structure of the central nervous system. The number of cell deaths to induce tissue abnormalities in adult brain rises in the range of 15-25% of the germinal cell population; and the threshold doses are about 0.3 Gy for cerebral defects and 1 Gy for cerebellar anomalies in both mice and rats. A similar threshold level is suggested in human cases in induction of mental retardation. Radiation-induced cell death in the VZ and EGL has been revealed as apoptosis, by the nuclear and cytoplasmic condensation, transglutaminase activation, required macromolecular synthesis, and internucleosomal DNA cleavage. Apoptosis of the germinal cell is assumed to eliminate acquired genetic damage. Once an abnormality in DNA has been induced and fixed in a germinal cell, it would be greatly amplified during future proliferation. These cells would commit suicide when injured for replacement by healthy cells, rather than undertake DNA repair. In fact they show very slow repair of cellular damage. Thus the high sensitivity of undifferentiated neural cells to the lethal effect of radiation may constitute a biological defense mechanism. (author) 69 refs

  15. High vulnerability of the developing brain to ionizing radiation

    International Nuclear Information System (INIS)

    Inouye, Minoru

    1991-01-01

    The developing mammalian brain is highly susceptible to environmental teratogenic insults, because of its long-lasting sensitive period extending from the beginning of embryonic organogenesis to the postnatal infantile period, the great vulnerability of undifferentiated neural cells to wide range of environmental agents including ionizing radiation, and the lack of further reproductive capacity of neurons. Disturbances in the production of neurons, and their migration to the cerebral and cerebellar cortices, give rise to malformations of the brain, such as an absent corpus callosum, disorganized cortical architecture, abnormal fissuring of the cerebral and cerebellar hemispheres, heterotopic cortical gray matter, ectopic cerebellar granule cells, microcephaly, etc. The critical developmental stage for the induction of histogenetic disorders of the cerebral cortex in humans is 8 weeks of pregnancy and following some weeks. This corresponds to day 13 of pregnancy for mice and day 15 for rats, i.e., the ventricular cells of fetal telencephalon are most susceptible to radiation-induced cell death in this stage of development. The lowest doses of X- and gamma-radiations which induce detectable biological effects in rats and mice are around 0.02 Gy in increasing acute cell death. Reduced brain weight and abnormal dendritic arborization are induced by 0.25 Gy and more. Histological abnormalities are produced by 0.5 Gy and more, and microcephaly and cerebellar malformations are by 1 Gy and more. (author)

  16. BIOLOGICAL EFFECTS OF MICROWAVE RADIATION ON BRAIN TISSUE IN RATS

    Directory of Open Access Journals (Sweden)

    Boris Đinđić

    2003-04-01

    Full Text Available Exposure to microwave radiation induces multiple organ dysfunctions, especially in CNS.The aim of this work was investigation of biological effects of microwave radiation on rats' brain and determination of increased oxidative stress as a possible pathogenetic's mechanism.Wis tar rats 3 months old were divided in experimental (4 female and 4 male animal and control group (5 female and 4 male. This experimental group was constantly exposed to a magnetic field of 5 mG. We simulated using of mobile phones 30 min every day. The source of NIR emitted MF that was similar to mobile phones at 900 MHz. The rats were killed after 2 months. Biological effects were determined by observation of individual and collective behavior and body mass changes. Lipid per oxidation was determined by measuring quantity of malondialdehyde (MDA in brain homogenate.The animals in experimental group exposed to EMF showed les weight gain. The most important observations were changing of basic behavior models and expression of aggressive or panic behavior. The content of MDA in brain tissue is singificantly higher (1.42 times in rats exposed to electromagnetic fields (3,82±0.65 vs. control 2.69±0.42 nmol/mg proteins, p<0.01.Increased oxidative stress and lipid peroxidation after exposition in EM fields induced disorders of function and structure of brain.

  17. Evoked bioelectrical brain activity following exposure to ionizing radiation.

    Science.gov (United States)

    Loganovsky, K; Kuts, K

    2017-12-01

    The article provides an overview of modern physiological evidence to support the hypothesis on cortico limbic sys tem dysfunction due to the hippocampal neurogenesis impairment as a basis of the brain interhemispheric asym metry and neurocognitive deficit after radiation exposure. The importance of the research of both evoked poten tials and fields as a highly sensitive and informative method is emphasized.Particular attention is paid to cerebral sensor systems dysfunction as a typical effect of ionizing radiation. Changes in functioning of the central parts of sensory analyzers of different modalities as well as the violation of brain integrative information processes under the influence of small doses of ionizing radiation can be critical when determining the radiation risks of space flight. The possible long term prospects for manned flights into space, including to Mars, given the effects identified are discussed. Potential risks to the central nervous system during space travel comprise cognitive functions impairment, including the volume of short term memory short ening, impaired motor functions, behavioral changes that could affect human performance and health. The remote risks for CNS are considered to be the following possible neuropsychiatric disorders: accelerated brain aging, Alzheimer's disease and other types of dementia. The new radiocerebral dose dependent effect, when applied cog nitive auditory evoked potentials P300 technique with a possible threshold dose of 0.05 Gy, manifesting in a form of disruption of information processing in the Wernicke's area is under discussion. In order to identify neurophys iological biological markers of ionizing radiation further international researches with adequate dosimetry support are necessary. K. Loganovsky, K. Kuts.

  18. Recursive N-way partial least squares for brain-computer interface.

    Directory of Open Access Journals (Sweden)

    Andrey Eliseyev

    Full Text Available In the article tensor-input/tensor-output blockwise Recursive N-way Partial Least Squares (RNPLS regression is considered. It combines the multi-way tensors decomposition with a consecutive calculation scheme and allows blockwise treatment of tensor data arrays with huge dimensions, as well as the adaptive modeling of time-dependent processes with tensor variables. In the article the numerical study of the algorithm is undertaken. The RNPLS algorithm demonstrates fast and stable convergence of regression coefficients. Applied to Brain Computer Interface system calibration, the algorithm provides an efficient adjustment of the decoding model. Combining the online adaptation with easy interpretation of results, the method can be effectively applied in a variety of multi-modal neural activity flow modeling tasks.

  19. Study on radiation necrosis following intraoperative radiotherapy for brain tumors

    International Nuclear Information System (INIS)

    Tanaka, Yoshiaki; Takeshita, Nagayuki; Niwa, Kohkichi; Kamata, Noriko; Matsuda, Tadayoshi; Matsutani, Masao

    1989-01-01

    Ninety-five patients with primary or metastatic brain tumors were treated with the intraoperative radiotherapy (IORT). In seven cases, surgery was performed a second time because of suspected of tumor recurrence, later found to be a radiation necrosis. Tumorous lesions were irradiated by IORT in the range of 15 Gy to 20 Gy together with external radiotherapy in the 30 Gy to 72 Gy range. In follow-up postcontrast CT studies, irregularly-shaped lesions appeared at the IORT site and increased in size with the perifocal low density area on subsequent scans. The images resembled those seen in tumor recurrence. Histopathologic changes seen during the follow-up surgery were thought to be mainly the result of radiation necrosis, though viable tumor cells at the marginal tumor site were one possible etiology. A coagulation necrosis with a fibrin exudate was observed in the IORT portal area and the vascular walls exhibited marked degeneration which is symptomatic of delayed radiation necrosis. Thus, post-IORT radiation necrosis is thought to be a direct reaction to this technique, and the delayed absorption of necrotic tissue to be a direct reaction to this technique, and the delayed absorption of necrotic tissue clearly indicates the possibility of adverse effects in its use for treatment of brain tumors. (author)

  20. Factors affecting radiation injury after interstitial brachytherapy for brain tumors

    International Nuclear Information System (INIS)

    Leibel, S.A.; Gutin, P.H.; Davis, R.L.

    1991-01-01

    The effects of brachytherapy on normal brain tissue are not easily delineated in the clinical setting because of the presence of concurrent radiation-induced changes in the coexistent brain tumor. Sequential morphologic studies performed after the implantation of radioactive sources into the brains of experimental animals have provided a better understanding of the character and magnitude of the structural changes produced by interstitial irradiation on normal brain tissue. Furthermore, the clinical experience accumulated thus far provides not only relevant information, but also some guidelines for future treatment policies. In this paper, the authors summarize the experimental findings and review the pathologic and clinical features of brain injury caused by interstitial brachytherapy. A number of studies in the older literature examined the effects of radioisotopes such as radium-226 (38--43), radon-22 (44--46), gold-198 (29,47--50), tantalum-182 (29,51,52) yttrium-9- (50,53,54), and cobalt-60 (29,50,55). This review is restricted to low- and high-activity encapsulated iodine-125 ( 125 I) and iridium-192 ( 192 Ir), the isotopes that are most commonly used in current clinical practice

  1. Effects of low dose radiation pretreatment on radiation injuried brain's free radicle

    International Nuclear Information System (INIS)

    Xu Fuqi; Wang Cheng; Xie Hong; Tian Ye

    2006-01-01

    Objective: To investigate the effect of low dose radiation pretreatment on radiation in- juried brain's free radicle to provide some useful data of brain radiation injury protection. Methods: One hundred mGy was selected as the pretreatment does, 25 Gy was selected as the challenge does. Experiment rats were divided into three groups randomly, group one as simple group:the group irradiated without exposing to pre-irradiation; group two as 6 h-group: the group irradiated with LDR pretreatment 6 h before exposing to 25 Gy irradiation; group three as 24 h-group:the group irradiated with LDR pretreatment 24 h before 25 Gy irradiation. The observation was done 6 hour's after irradiation, the effect of LDR pretreatment on increasing activity of the superoxide dismutase(SOD) and the content of malondialdehyde(MDA) after the brain tissue homogenate were detected. Results: Com- pared with the simple group, the group with LDR pretreatment showed increasing of SOD and decreasing of MDA at the 6th hour after 25Gy irradiation. In addition, there was no difference between the 6 h-group and the 24 h-group. Conclusion: LDR pretreatment can increase SOD and decrease MDA in some period. It could infer that the suitable LDR pretreatment could play a protective role in the brain radiation injury. (authors)

  2. An Efficient and Reliable Statistical Method for Estimating Functional Connectivity in Large Scale Brain Networks Using Partial Correlation.

    Science.gov (United States)

    Wang, Yikai; Kang, Jian; Kemmer, Phebe B; Guo, Ying

    2016-01-01

    Currently, network-oriented analysis of fMRI data has become an important tool for understanding brain organization and brain networks. Among the range of network modeling methods, partial correlation has shown great promises in accurately detecting true brain network connections. However, the application of partial correlation in investigating brain connectivity, especially in large-scale brain networks, has been limited so far due to the technical challenges in its estimation. In this paper, we propose an efficient and reliable statistical method for estimating partial correlation in large-scale brain network modeling. Our method derives partial correlation based on the precision matrix estimated via Constrained L1-minimization Approach (CLIME), which is a recently developed statistical method that is more efficient and demonstrates better performance than the existing methods. To help select an appropriate tuning parameter for sparsity control in the network estimation, we propose a new Dens-based selection method that provides a more informative and flexible tool to allow the users to select the tuning parameter based on the desired sparsity level. Another appealing feature of the Dens-based method is that it is much faster than the existing methods, which provides an important advantage in neuroimaging applications. Simulation studies show that the Dens-based method demonstrates comparable or better performance with respect to the existing methods in network estimation. We applied the proposed partial correlation method to investigate resting state functional connectivity using rs-fMRI data from the Philadelphia Neurodevelopmental Cohort (PNC) study. Our results show that partial correlation analysis removed considerable between-module marginal connections identified by full correlation analysis, suggesting these connections were likely caused by global effects or common connection to other nodes. Based on partial correlation, we find that the most significant

  3. How to identify partial exposures to ionizing radiation? Proposal for a cytogenetic method

    International Nuclear Information System (INIS)

    Fernandes, T.S.; Silva, E.B.; Pinto, M.M.P.L.; Amaral, A.; Lloyd, David

    2013-01-01

    In cases of radiological incidents or in occupational exposures to ionizing radiation, the majority of exposures are not related to the total body, but only partial. In this context, if the cytogenetic dosimetry is performed, there will be an underestimation of the absorbed dose due to the dilution of irradiated cells with non-irradiated cells. Considering the norms of NR 32 - Safety and Health in the Work of Health Service - which recommends cytogenetic dosimetry in the investigation of accidental exposures to ionizing radiations, it is necessary to develop of a tool to provide a better identification of partial exposures. With this aim, a partial body exposure was simulated by mixing, in vitro, 70% of blood irradiated with 4 Gy of X-rays with 30% of unirradiated blood from the same healthy donor. Aliquots of this mixture were cultured for 48 and 72 hours. Prolonging the time of cell culture from 48 to 72 hours produced no significant change in the yield of dicentrics. However, when only M1 (first division cells) were analyzed, the frequency of dicentrics per cell was increased. Prolonging the time of cell culture allowed cells in mitotic delay by irradiation to reach metaphase, and thus provides enough time for the damage to be visualized. The results of this research present the proposed method as an important tool in the investigation of exposed individuals, allowing associating the cytogenetic analysis with the real percentage of irradiated cells, contributing significantly for the decision making in terms of occupational health. (author)

  4. Effect of Gamma Radiation sterilization versus Disinfection on Removable Partial Dentures (Microbiological study)

    International Nuclear Information System (INIS)

    Mohammed, M.A.

    2011-01-01

    The aim of the study was to compare between the effectiveness of disinfection, using commercially available Fittydent super cleansing tablets versus sterilization, using gamma radiation on candidal growth in maxillary removable partial dentures. Methods: Fourteen partially edentulous subjects were selected according to specific criteria and divided equally and randomly into two groups; Group I: disinfection group and Group II: sterilization group. Conventional maxillary removable partial dentures were constructed for all subjects. The swab technique was used to collect the samples one month after denture delivery, immediately after disinfection/sterilization, and then one week, two weeks, three weeks, four weeks, and five weeks after disinfection/sterilization respectively. Bacteriological candidal colony count was performed using a manual contact colony counter. Results: Both methods (disinfection and sterilization) led to a noticeable decrease in the candidal count. However this decrease was highly and markedly evident in Group II as compared to Group I. Infact, no candidal growth was recorded for group II immediately after strerilization and was maintained for two more weeks. Statistical analysis revealed highly significant differences between the two groups. Conclusions: Both methods were effective in decreasing the number of Candida albicans adhering to the denture. However, sterilization using Gamma radiation had a more superior immediate, as well as, long term efficiency as compared to disinfection using Fittydent super cleansing tablets.

  5. Biological Dosimetry Using Micronucleus Assay in Simulated Partial-Body Exposure to Ionizing Radiation

    Directory of Open Access Journals (Sweden)

    S. Purnami

    2017-08-01

    Full Text Available In radiation accidents, it is common that only several parts of the body are exposed to radiation. As a consequence there is a mixture of exposed and unexposed lymphocytes in peripheral blood cells of the samples. This phenomenon will cause the dose value estimated using the exposed lymphocytes to be lower than the actual dose. In this study, an assessment of partial body exposures using micronucleus assay by estimating the partial body dose and fraction of irradiated blood was conducted. An optimal D0 value also has been determined in this study to estimate the fraction of irradiated cells. Peripheral blood lymphocytes (PBLs from three healthy donors were irradiated in vitro with 2 Gy of X-rays. Partial radiation exposure was simulated by mixing the irradiated and non-irradiated blood in different proportions. The proportions of mixtures of blood samples irradiated in vitro were 5, 10, 15, 20, and 30 %. Blood samples were then cultured and harvested based on micronuclei assay protocol. At least 2000 binucleated cells with well-preserved cytoplasm were scored for the MN frequency. Dose Estimate 5.1 software was used to calculate the dispersion index (σ2/y and normalized unit of this index (U in each proportion of bloods. The fractions of irradiated cells were calculated with CABAS (Chromosomal Aberration Calculation Software for several different D0 values (2.7; 3.8; 5.4. The results showed that D0 value at 5.4 gave the closest results to the actual proportion of irradiated bloods, while for the dose estimation the estimated doses value from all proportions in all donors were higher than the actual dose. The factor that may cause this phenomenon was that the dose response calibration curve used to predict the radiation dose was not constructed in the laboratory used. Overall it can be concluded that a biodosimetry using MN assay can be used to estimate the radiation dose in partial body exposure. In order to establish a biodosimetry using MN

  6. Sound Radiation from a Supersonic Jet Passing Through a Partially Open Exhaust Duct

    Science.gov (United States)

    Kandula, Max

    2011-01-01

    The radiation of sound from a perfectly expanded Mach 2.5 cold supersonic jet of 25.4 mm exit diameter flowing through a partially open rigid-walled duct with an upstream i-deflector has been studied experimentally. In the experiments, the nozzle is mounted vertically, with the nozzle exit plane at a height of 73 jet diameters above ground level. Relative to the nozzle exit plane (NEP), the location of the duct inlet is varied at 10, 5, and -1 jet diameters. Far-field sound pressure levels were obtained at 54 jet diameters above ground with the aid of acoustic sensors equally spaced around a circular arc of radius equal to 80 jet diameters from the jet axis. Data on the jet acoustic field for the partially open duct were obtained and compared with those with a free jet and with a closed duct. The results suggest that for the partially open duct the overall sound pressure level (OASPL) decreases as the distance between the NEP and the duct inlet plane decreases, while the opposite trend is observed for the closed duct. It is also concluded that the observed peak frequency in the partially open duct increases above the free jet value as the angle from the duct axis is increased, and as the duct inlet plane becomes closer to the NEP.

  7. Dose-volume considerations in stereotaxic brain radiation therapy

    International Nuclear Information System (INIS)

    Houdek, P.V.; Schwade, J.G.; Pisciotta, V.J.; Medina, A.J.; Lewin, A.A.; Abitbol, A.A.; Serago, C.F.

    1988-01-01

    Although brain radiation therapy experience suggests that a gain in the therapeutic ratio may be achieved by optimizing the dose-volume relationship, no practical system for quantitative assessment of dose-volume data has been developed. This presentation describes the rationale for using the integral dose function for this purpose and demonstrates that with the use of a conventional treatment planning computer and a series of computed tomographic scans, first-order optimization of the dose-volume function can be accomplished in two steps: first, high-dose volume is minimized by selecting an appropriate treatment technique and tumor margin, and then dosage is maximized by calculating the brain tolerance dose as a function of the irradiated volume

  8. Radiation Dose-Volume Effects in the Brain

    International Nuclear Information System (INIS)

    Lawrence, Yaacov Richard; Li, X. Allen; El Naqa, Issam; Hahn, Carol A.; Marks, Lawrence B.; Merchant, Thomas E.; Dicker, Adam P.

    2010-01-01

    We have reviewed the published data regarding radiotherapy (RT)-induced brain injury. Radiation necrosis appears a median of 1-2 years after RT; however, cognitive decline develops over many years. The incidence and severity is dose and volume dependent and can also be increased by chemotherapy, age, diabetes, and spatial factors. For fractionated RT with a fraction size of 80 Gy. For large fraction sizes (≥2.5 Gy), the incidence and severity of toxicity is unpredictable. For single fraction radiosurgery, a clear correlation has been demonstrated between the target size and the risk of adverse events. Substantial variation among different centers' reported outcomes have prevented us from making toxicity-risk predictions. Cognitive dysfunction in children is largely seen for whole brain doses of ≥18 Gy. No substantial evidence has shown that RT induces irreversible cognitive decline in adults within 4 years of RT.

  9. Multivoxel proton MRS for differentiation of radiation-induced necrosis and tumor recurrence after gamma knife radiosurgery for brain metastases

    International Nuclear Information System (INIS)

    Chernov, M.F.; Hayashi, Motohiro; Izawa, Masahiro

    2006-01-01

    Multivoxel proton magnetic resonance spectroscopy (MRS) was used for differentiation of radiation-induced necrosis and tumor recurrence after gamma knife radiosurgery for intracranial metastases in 33 consecutive cases. All patients presented with enlargement of the treated lesion, increase of perilesional brain edema, and aggravation or appearance of neurological signs and symptoms on average 9.3±4.9 months after primary treatment. Metabolic imaging defined four types of lesions: pure tumor recurrence (11 cases), partial tumor recurrence (11 cases), radiation-induced tumor necrosis (10 cases), and radiation-induced necrosis of the peritumoral brain (1 case). In 1 patient, radiation-induced tumor necrosis was diagnosed 9 months after radiosurgery; however, partial tumor recurrence was identified 6 months later. With the exception of midline shift, which was found to be more typical for radiation-induced necrosis (P<0.01), no one clinical, radiologic, or radiosurgical parameter either at the time of primary treatment or at the time of deterioration showed a statistically significant association with the type of the lesion. Proton MRS-based diagnosis was confirmed histologically in all surgically treated patients (7 cases) and corresponded well to the clinical course in others. In conclusion, multivoxel proton MRS is an effective diagnostic modality for identification of radiation-induced necrosis and tumor recurrence that can be used for monitoring of metabolic changes in intracranial neoplasms after radiosurgical treatment. It can be also helpful for differentiation of radiation-induced necrosis of the tumor and that of the peritumoral brain, which may have important clinical and medicolegal implications. (author)

  10. MR imaging assisted radiation therapy planning of brain tumors

    International Nuclear Information System (INIS)

    Just, M.; Roesler, H.P.; Higer, H.P.; Kutzner, J.; Thelen, M.

    1990-01-01

    This paper reports on the improvement of the accuracy of treatment portals in radiation therapy of brain tumors with use of MR imaging. After proper processing, the parasagittal MR image showing the largest tumor size and the midline sagittal image were superimposed. With common anatomic landmarks of midline tomogram and lateral simulation radiograph, commensurate reference grids were laid over both images in identical positions. Tumor coordinates were then transferred from the synthesized MR image to the lateral radiograph. Rectangular fields or individual shielding blocks encompassing the tumor could be drawn directly. This new method was used in 17 patients, and results were compared with CT-assisted results

  11. Somatic radiation risk in case of irradiation of the brain

    Energy Technology Data Exchange (ETDEWEB)

    Nocken, U.; Ewen, K.; Makoski, H.B.

    1983-09-01

    The somatic dose index for irradiation of the brain was determined for the 10 MeV bremsstrahlung of a linear electron-accelerator. A small volume rotation technique and the irradiation of the total neurocranium were chosen as extreme conditions for the radiation exposure of the skull. On the basis of a target volume dose of 50 Gy for the total irradiation series, the somatic dose index of the small volume technique is within the scope of coronarography. In case of irradiation of the total neurocranium, however, the somatic dose index largely exceeds the maximum values of X-ray diagnosis.

  12. Partial inhibition of in vitro pollen germination by simulated solar ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Flint, S.D.; Caldwell, M.M.

    1984-01-01

    Pollen from four temperate-latitude taxa were treated with UV radiation in a portion of the UV-B (280-320 nm) waveband during in vitro germination. Inhibition of germination was noted in this pollen compared to samples treated identically except for the exclusion of the UV-B portion of the spectrum. Levels similar to maximum solar UV-B found in temperate-latitude areas failed to inhibit pollen germination significantly, while levels similar to maximum solar UV-B found in equatorial alpine locations caused partial inhibition of germination in three of the four taxa examined

  13. Clinical utility of partial flip angle T2-weighted spin-echo imaging of the brain

    International Nuclear Information System (INIS)

    Chang, K.H.; Yi, J.G.; Han, M.H.; Han, M.C.; Kim, C.W.; Cho, M.H.; Cho, Z.H.

    1990-01-01

    To assess the clinical usefulness of partial flip angle (PFA) spin-echo (SE) brain imaging, a total of eighty patients were examined with both conventional double echo T2-weighted SE (2500/30, 80/90deg/one excitation) and PFA double echo SE (1200/30, 70/45deg/two excitations) on 2.0T system. Two comparative studies were performed: (1) In 65 patients PFA SE technique was compared with conventional SE without flow compensating gradients, and (2) in 15 patients the former was compared with the latter with flow compensating gradients. Imaging time was nearly identical in each sequence. In both studies we found that PFA T2-weighted SE images were almost identical to those obtained with the conventional SE technique in the contrast characteristics and the detection rate of the abnormalities (100%, 85/85 lesions), and more importantly, PFA SE revealed few flow artifacts in the brain stem, temporal lobes and basal ganglia which were frequently seen on conventional SE without flow compensating gradients. Additionally, PFA SE images demonstrated no suppression of CSF flow void in the aqueduct which was commonly seen on conventional SE with flow compensating gradients. In overall image quality, the PFA SE images, particularly the second echo images, were almost comparable with those of conventional SE with flow compensating gradients. A flip angle of 45deg seems to be close to Ernst angle, the angle at which maximum signal occurs, for a given TR of 1200 msec for CSF and most of the abnormalities containing higher water content. In conclusion, PFA SE sequence (i.e. 1200/30, 70/45deg/2) appears to be useful as a primary or an adjunctive technique in certain clinical circumstances, particularly in imaging of hydrocephalic patients for assessing aqueductal patency. (orig.)

  14. Murine partial-body radiation exposure model for biodosimetry studies - Preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Blakely, William F., E-mail: blakely@afrri.usuhs.mil [Uniformed Services University, Armed Forces Radiobiology Research Institute, Scientific Research Department, 8901 Wisconsin Avenue, Bethesda, MD 20889-5603 (United States); Sandgren, David J., E-mail: Sandgren@afrri.usuhs.mil [Uniformed Services University, Armed Forces Radiobiology Research Institute, Scientific Research Department, 8901 Wisconsin Avenue, Bethesda, MD 20889-5603 (United States); Nagy, Vitaly, E-mail: nagy@afrri.usuhs.mil [Uniformed Services University, Armed Forces Radiobiology Research Institute, Scientific Research Department, 8901 Wisconsin Avenue, Bethesda, MD 20889-5603 (United States); Kim, Sung-Yop, E-mail: kimy@afrri.usuhs.mil [Uniformed Services University, Armed Forces Radiobiology Research Institute, Scientific Research Department, 8901 Wisconsin Avenue, Bethesda, MD 20889-5603 (United States); Ossetrova, Natalia I., E-mail: ossetrova@afrri.usuhs.mil [Uniformed Services University, Armed Forces Radiobiology Research Institute, Scientific Research Department, 8901 Wisconsin Avenue, Bethesda, MD 20889-5603 (United States)

    2011-09-15

    The objective of the present study was to establish a murine partial-body radiation exposure model for studies supporting the identification and validation of novel biological dosimetry diagnostic assays. A lead shielding - Plexiglas irradiation apparatus with cutouts to permit irradiation of single-mouse-holder constrained CD2F1 male mice to total-body (3/3), mid- and lower-body (2/3), mid-body only (1/3), and 100% lead shielding sham-treated (0 Gy) controls (0/3) with a 250-kVp X-ray source (dose: 6 Gy, dose rate: 0.50 Gy min{sup -1}) was used. Doses and dose uniformity were measured using alanine - electron paramagnetic resonance (EPR) and ionization chambers. Dosimetry mapping results showed {approx}2 and {approx}12% non-uniformity in the radiation fields for the two smaller (1/3, 2/3) and one larger (3/3) fields, respectively. Hematology results showed no marked differences in neutrophil and platelet counts 1 and 2 days (d) after irradiation. The lymphocyte counts, as expected, demonstrate a progressive decline below baseline levels 1 and 2 d after irradiation with increasing fraction of the body exposed, while the neutrophil to lymphocyte ratios show the inverse effect, with a progressive increase with the fraction of body exposed. The bone marrow biomarker, Flt3 ligand, demonstrated a progressive increase in values with increasing fraction of the body exposed; the 2 d response was enhanced compared to 1 d. The radioresponse 1 d after irradiation for the acute phase reactant protein biomarker, serum amyloid A (SAA) that is synthesized by the liver, was significantly influenced depending on whether the mouse head was in the radiation field. Use of multiple biomarkers based on hematology and proteomic targets provide an enhancement in early-phase partial-body radiation exposure assessment.

  15. A case of leukoencephalopathy caused by radiation and chemotherapy for brain metastasis of breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Shigeru; Sonoo, Hiroshi; Nomura, Tsunehisa; Ohkubo, Sumiko; Yamamoto, Yutaka; Tanaka, Katsuhiro; Kurebayashi, Junichi; Hiratsuka, Junichi [Kawasaki Medical School, Kurashiki, Okayama (Japan)

    2002-08-01

    A case of treatment-related leukoencephalopathy is presented. A patient with breast cancer metastasis to the brain, liver, bone and distant lymph nodes was treated with whole brain radiation and docetaxcel. Eleven months after radiation, magnetic resonance imaging showed diffuse leukoencephalopathy. Twenty-two months after radiation, the patient had gait disturbance, parkinsonism, dementia and urinary incontinence. From this experience, stereotactic radiosurgery such as cyber knife and gamma knife therapy, representing a new modality for delivering intense focal radiation, should be come preferred techniques for treating patients with brain metastases, to avoid the potential cognitive side effects of fractionated whole-brain radiotherapy. (author)

  16. Holmium-166-chico intracavitary radiation therapy for cystic brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, C. H.; Lee, S. H.; Jang, J. S.; Kim, E. H.; Choi, C. W.; Hong, S. W.; Lim, S. M. [Korea Cancer Center, Seoul (Korea, Republic of)

    1997-07-01

    Holmium-166-chitosan complex (Ho-166-chico) is injected into the unresectable seven cystic brain tumors (2 cases of metastatic brain tumors from lung cancer, 1 case of recurrent trigeminal neurinoma, 3 cases of recurrent low grade cystic astrocytomas, and 1 case of craniopharyngioma). The Ommaya reservoir was installed stereotactically. The cyst volume and wall thickness were measured by MRI before Ho-166-chico injection. The thickness of the cyst wall is up to 4 mm. Ho-166-chico (555-740 MBq) injected into the cyst to result in 25 Gy of dose to a cyst wall at a depth of 4 mm. Dose to the cyst wall was estimated by Monte Carlo simulation using the EGS4 code. All Ho-166-chico injected was assumed to be uniformly distributed in the spherical cyst. After Ho-166-chico injection, the distribution of isotopes was monitored by gamma camera. Two injections were administrated in two cases, and one injection in all the others. The response was evaluated with MRI. Four of 7 cases were shrunk in size with thinning of the cyst wall, 2 of 7 cases showed growth arrest, and one case showed progression. Estimated surface dose of cyst wall was between 78 and 2566 Gy. No one showed systemic absorption of Ho-166-chico, and specific complication associated with isotope injection. Ho-166-chico intracavitary radiation therapy for cystic brain tumor may be safe, and reliable method and deserves further evaluation.

  17. Discordance Between Preoperative and Postoperative Bladder Cancer Location: Implications for Partial-Bladder Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Goldsmith, Benjamin; Tucker, Kai; Conway, Robert Greg; He, Jiwei [Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Guzzo, Thomas [Department of Urology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Bekelman, Justin; Deville, Curtiland; Vapiwala, Neha [Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Malkowicz, S. Bruce [Department of Urology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Christodouleas, John, E-mail: christojo@uphs.upenn.edu [Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania (United States)

    2013-03-01

    Purpose: There is strong interest in partial-bladder radiation whether as a boost or definitive therapy to limit long-term toxicity. It is unclear that a standard preoperative examination can accurately identify all sites of disease within the bladder. The purpose of this study was to determine the correlation between preoperative localization of bladder tumors with postoperative findings to facilitate partial-bladder radiation techniques when appropriate. Methods and Materials: We examined patients with clinically staged T1-T4 invasive transitional cell carcinoma (TCC) or TCC with variant histology with no history of radiation or partial cystectomy undergoing radical cystectomy. Patients were scored as “under-detected” if a bladder site was involved with invasive disease (≥T1) at the time of cystectomy, but not identified preoperatively. Patients were additionally scored as “widely under-detected” if they had postoperative lesions that were not identified preoperatively in a given site, nor in any adjacent site. Rates of under-detected and widely under-detected lesions, as well as univariate and multivariate association between clinical variables and under-detection, were evaluated using logistic regression. Results: Among 222 patients, 96% (213/222) had at least 1 area of discordance. Fifty-eight percent of patients were under-detected in at least 1 location, whereas 12% were widely under-detected. Among 24 patients with a single site of disease on preoperative evaluation, 21/24 (88%) had at least 1 under-detected lesion and 14/24 (58%) were widely under-detected. On multivariate analysis, only solitary site of preoperative disease was associated with increased levels of under-detection of invasive disease (OR = 4.161, 95% CI, 1.368-12.657). Conclusion: Our study shows a stark discordance between preoperative and postoperative localization of bladder tumors. From a clinical perspective, incomplete localization of all sites of disease within the bladder

  18. Early radiation changes of normal dog brain following internal and external brain irradiation: A preliminary report

    International Nuclear Information System (INIS)

    Chin, H.; Maruyama, Y.; Markesbery, W.; Goldstein, S.; Wang, P.; Tibbs, P.; Young, B.; Feola, J.; Beach, L.

    1984-01-01

    To examine radiation-induced changes in the normal brain, internal or external radiation was given to normal dog brain. Seven medium-sized dogs were used in this study. Two dogs were controls and an ice-pick (plastic implant applicator) was placed in the right frontal lobe for about 5 hours but no irradiation. Two dogs underwent Cs-137 brain implantation for 4 and 5 hours, respectively using an ice-pick technique. Two dogs were given internal neutron irradiation using the same technique of intracerebral ice-pick brachytherapy. One dog received an external photon irradiation using 6-Mev Linear Accelerator. Postmortem microscopic examination was made to study the early cerebral changes to irradiation in three dogs: one control with no irradiation; one received intracerebral Cesium implantation; and one external photon irradiation. Vascular change was the most prominent microscopic finding. There were hemorrhage, endothelial proliferation and fibrinoid changes of small vessel wall. Most of the changes were localized in the white matter and the cortex remained intact. Details (CT, NMR and histological studies) are discussed

  19. Clinical application of RapidArc volumetric modulated arc therapy as a component in whole brain radiation therapy for poor prognostic, four or more multiple brain metastases

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Heon; Lee, Kyu Chan; Choi, Jin Ho; Kim, Hye Young; Lee, Seok Ho; Sung, Ki Hoon; Kim, Yun Mi [Gachon University Gil Hospital, Incheon (Korea, Republic of)

    2012-06-15

    To determine feasibility of RapidArc in sequential or simultaneous integrated tumor boost in whole brain radiation therapy (WBRT) for poor prognostic patients with four or more brain metastases. Nine patients with multiple ({>=}4) brain metastases were analyzed. Three patients were classified as class II in recursive partitioning analysis and 6 were class III. The class III patients presented with hemiparesis, cognitive deficit, or apraxia. The ratio of tumor to whole brain volume was 0.8-7.9%. Six patients received 2-dimensional bilateral WBRT, (30 Gy/10- 12 fractions), followed by sequential RapidArc tumor boost (15-30 Gy/4-10 fractions). Three patients received RapidArc WBRT with simultaneous integrated boost to tumors (48-50 Gy) in 10-20 fractions. The median biologically effective dose to metastatic tumors was 68.1 Gy10 and 67.2 Gy10 and the median brain volume irradiated more than 100 Gy3 were 1.9% (24 cm3) and 0.8% (13 cm3) for each group. With less than 3 minutes of treatment time, RapidArc was easily applied to the patients with poor performance status. The follow-up period was 0.3-16.5 months. Tumor responses among the 6 patients who underwent follow-up magnetic resonance imaging were partial and stable in 3 and 3, respectively. Overall survival at 6 and 12 months were 66.7% and 41.7%, respectively. The local progression-free survival at 6 and 12 months were 100% and 62.5%, respectively. RapidArc as a component in whole brain radiation therapy for poor prognostic, multiple brain metastases is an effective and safe modality with easy application.

  20. Early Cognitive Outcomes Following Proton Radiation in Pediatric Patients With Brain and Central Nervous System Tumors

    International Nuclear Information System (INIS)

    Pulsifer, Margaret B.; Sethi, Roshan V.; Kuhlthau, Karen A.; MacDonald, Shannon M.; Tarbell, Nancy J.; Yock, Torunn I.

    2015-01-01

    Purpose: To report, from a longitudinal study, cognitive outcome in pediatric patients treated with proton radiation therapy (PRT) for central nervous system (CNS) tumors. Methods and Materials: Sixty patients receiving PRT for medulloblastoma (38.3%), gliomas (18.3%), craniopharyngioma (15.0%), ependymoma (11.7%), and other CNS tumors (16.7%) were administered age-appropriate measures of cognitive abilities at or near PRT initiation (baseline) and afterward (follow-up). Patients were aged ≥6 years at baseline to ensure consistency in neurocognitive measures. Results: Mean age was 12.3 years at baseline; mean follow-up interval was 2.5 years. Treatment included prior surgical resection (76.7%) and chemotherapy (61.7%). Proton radiation therapy included craniospinal irradiation (46.7%) and partial brain radiation (53.3%). At baseline, mean Wechsler Full Scale IQ was 104.6; means of all 4 Index scores were also in the average range. At follow-up, no significant change was observed in mean Wechsler Full Scale IQ, Verbal Comprehension, Perceptual Reasoning/Organization, or Working Memory. However, Processing Speed scores declined significantly (mean 5.2 points), with a significantly greater decline for subjects aged <12 years at baseline and those with the highest baseline scores. Cognitive outcome was not significantly related to gender, extent of radiation, radiation dose, tumor location, histology, socioeconomic status, chemotherapy, or history of surgical resection. Conclusions: Early cognitive outcomes after PRT for pediatric CNS tumors are encouraging, compared with published outcomes from photon radiation therapy

  1. Early Cognitive Outcomes Following Proton Radiation in Pediatric Patients With Brain and Central Nervous System Tumors

    Energy Technology Data Exchange (ETDEWEB)

    Pulsifer, Margaret B., E-mail: mpulsifer@mgh.harvard.edu [Department of Psychiatry, Massachusetts General Hospital, Boston, Massachusetts (United States); Sethi, Roshan V. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Kuhlthau, Karen A. [Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts (United States); MacDonald, Shannon M.; Tarbell, Nancy J.; Yock, Torunn I. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2015-10-01

    Purpose: To report, from a longitudinal study, cognitive outcome in pediatric patients treated with proton radiation therapy (PRT) for central nervous system (CNS) tumors. Methods and Materials: Sixty patients receiving PRT for medulloblastoma (38.3%), gliomas (18.3%), craniopharyngioma (15.0%), ependymoma (11.7%), and other CNS tumors (16.7%) were administered age-appropriate measures of cognitive abilities at or near PRT initiation (baseline) and afterward (follow-up). Patients were aged ≥6 years at baseline to ensure consistency in neurocognitive measures. Results: Mean age was 12.3 years at baseline; mean follow-up interval was 2.5 years. Treatment included prior surgical resection (76.7%) and chemotherapy (61.7%). Proton radiation therapy included craniospinal irradiation (46.7%) and partial brain radiation (53.3%). At baseline, mean Wechsler Full Scale IQ was 104.6; means of all 4 Index scores were also in the average range. At follow-up, no significant change was observed in mean Wechsler Full Scale IQ, Verbal Comprehension, Perceptual Reasoning/Organization, or Working Memory. However, Processing Speed scores declined significantly (mean 5.2 points), with a significantly greater decline for subjects aged <12 years at baseline and those with the highest baseline scores. Cognitive outcome was not significantly related to gender, extent of radiation, radiation dose, tumor location, histology, socioeconomic status, chemotherapy, or history of surgical resection. Conclusions: Early cognitive outcomes after PRT for pediatric CNS tumors are encouraging, compared with published outcomes from photon radiation therapy.

  2. Trans-differentiation of neural stem cells: a therapeutic mechanism against the radiation induced brain damage.

    Directory of Open Access Journals (Sweden)

    Kyeung Min Joo

    Full Text Available Radiation therapy is an indispensable therapeutic modality for various brain diseases. Though endogenous neural stem cells (NSCs would provide regenerative potential, many patients nevertheless suffer from radiation-induced brain damage. Accordingly, we tested beneficial effects of exogenous NSC supplementation using in vivo mouse models that received whole brain irradiation. Systemic supplementation of primarily cultured mouse fetal NSCs inhibited radiation-induced brain atrophy and thereby preserved brain functions such as short-term memory. Transplanted NSCs migrated to the irradiated brain and differentiated into neurons, astrocytes, or oligodendrocytes. In addition, neurotrophic factors such as NGF were significantly increased in the brain by NSCs, indicating that both paracrine and replacement effects could be the therapeutic mechanisms of NSCs. Interestingly, NSCs also differentiated into brain endothelial cells, which was accompanied by the restoration the cerebral blood flow that was reduced from the irradiation. Inhibition of the VEGF signaling reduced the migration and trans-differentiation of NSCs. Therefore, trans-differentiation of NSCs into brain endothelial cells by the VEGF signaling and the consequential restoration of the cerebral blood flow would also be one of the therapeutic mechanisms of NSCs. In summary, our data demonstrate that exogenous NSC supplementation could prevent radiation-induced functional loss of the brain. Therefore, successful combination of brain radiation therapy and NSC supplementation would provide a highly promising therapeutic option for patients with various brain diseases.

  3. Evaluation of the reconstruction method and effect of partial volume in brain scintiscanning

    International Nuclear Information System (INIS)

    Pinheiro, Monica Araujo

    2016-01-01

    Alzheimer's disease is a neurodegenerative disorder, on which occurs a progressive and irreversible destruction of neurons. According to the World Health Organization (WHO) 35.6 million people are living with dementia, being recommended that governments prioritize early diagnosis techniques. Laboratory and psychological tests for cognitive assessment are conducted and further complemented by neurological imaging from nuclear medicine exams in order to establish an accurate diagnosis. The image quality evaluation and reconstruction process effects are important tools in clinical routine. In the present work, these quality parameters were studied, and the effects of partial volume (PVE) for lesions of different sizes and geometries that are attributed to the limited resolution of the equipment. In dementia diagnosis, this effect can be confused with intake losses due to cerebral cortex atrophy. The evaluation was conducted by two phantoms of different shapes as suggested by (a) American College of Radiology (ACR) and (b) National Electrical Manufacturers Association (NEMA) for Contrast, Contrast-to-Noise Ratio (CNR) and Recovery Coefficient (RC) calculation versus lesions shape and size. Technetium-99m radionuclide was used in a local brain scintigraphy protocol, for proportions lesion to background of 2:1, 4:1, 6:1, 8:1 and 10:1. Fourteen reconstruction methods were used for each concentration applying different filters and algorithms. Before the analysis of all image properties, the conclusion is that the predominant effect is the partial volume, leading to errors of measurement of more than 80%. Furthermore, it was demonstrate that the most effective method of reconstruction is FBP with Metz filter, providing better contrast and contrast to noise ratio results. In addition, this method shows the best Recovery Coefficients correction for each lesion. The ACR phantom showed the best results assigned to a more precise reconstruction of a cylinder, which does not

  4. Radiation-induced brain tumours: potential late complications of radiation therapy for brain tumours

    International Nuclear Information System (INIS)

    Nishio, S.; Morioka, T.; Inamura, T.; Takeshita, I.; Fukui, M.; Sasaki, M.; Nakamura, K.; Wakisaka, S.

    1998-01-01

    The development of neoplasms subsequent to therapeutic cranial irradiation is a rare but serious and potentially fatal complication. In this study, we retrospectively reviewed the clinical and pathological aspects of 11 patients who underwent cranial irradiation (range, 24-110 cGy) to treat their primary disease and thereafter developed secondary tumours within a span of 13 years. All tumours arose within the previous radiation fields, and satisfied the widely used criteria for the definition of radiation-induced neoplasms. There was no sex predominance (M: 5, F: 6) and the patients tended to be young at irradiation (1.3 - 42 years; median age: 22 years). The median latency period before the detection of the secondary tumour was 14.5 years (range: 6.5 - 24 years). Meningiomas developed in 5 patients, sarcomas in 4, and malignant gliomas in 2. A pre-operative diagnosis of a secondary tumour was correctly obtained in 10 patients based on the neuro-imaging as well as nuclear medicine findings. All patients underwent a surgical removal of the secondary tumour, 3 underwent additional chemotherapy, and one received stereotactic secondary irradiation therapy. During a median of 2 years of follow-up review after the diagnosis of a secondary tumour, 3 patients died related to the secondary tumours (2 sarcomas, 1 glioblastoma), one died of a recurrent primary glioma, while the remaining 7 have been alive for from 10 months to 12 years after being treated for the secondary tumours (median: 3 years). Based on these data, the clinicopathological characteristics and possible role of treatment for secondary tumours are briefly discussed. (author)

  5. GAUSS-SEIDEL AND SUCCESSIVE OVERRELAXATION METHODS FOR RADIATIVE TRANSFER WITH PARTIAL FREQUENCY REDISTRIBUTION

    International Nuclear Information System (INIS)

    Sampoorna, M.; Bueno, J. Trujillo

    2010-01-01

    The linearly polarized solar limb spectrum that is produced by scattering processes contains a wealth of information on the physical conditions and magnetic fields of the solar outer atmosphere, but the modeling of many of its strongest spectral lines requires solving an involved non-local thermodynamic equilibrium radiative transfer problem accounting for partial redistribution (PRD) effects. Fast radiative transfer methods for the numerical solution of PRD problems are also needed for a proper treatment of hydrogen lines when aiming at realistic time-dependent magnetohydrodynamic simulations of the solar chromosphere. Here we show how the two-level atom PRD problem with and without polarization can be solved accurately and efficiently via the application of highly convergent iterative schemes based on the Gauss-Seidel and successive overrelaxation (SOR) radiative transfer methods that had been previously developed for the complete redistribution case. Of particular interest is the Symmetric SOR method, which allows us to reach the fully converged solution with an order of magnitude of improvement in the total computational time with respect to the Jacobi-based local accelerated lambda iteration method.

  6. Gauss-Seidel and Successive Overrelaxation Methods for Radiative Transfer with Partial Frequency Redistribution

    Science.gov (United States)

    Sampoorna, M.; Trujillo Bueno, J.

    2010-04-01

    The linearly polarized solar limb spectrum that is produced by scattering processes contains a wealth of information on the physical conditions and magnetic fields of the solar outer atmosphere, but the modeling of many of its strongest spectral lines requires solving an involved non-local thermodynamic equilibrium radiative transfer problem accounting for partial redistribution (PRD) effects. Fast radiative transfer methods for the numerical solution of PRD problems are also needed for a proper treatment of hydrogen lines when aiming at realistic time-dependent magnetohydrodynamic simulations of the solar chromosphere. Here we show how the two-level atom PRD problem with and without polarization can be solved accurately and efficiently via the application of highly convergent iterative schemes based on the Gauss-Seidel and successive overrelaxation (SOR) radiative transfer methods that had been previously developed for the complete redistribution case. Of particular interest is the Symmetric SOR method, which allows us to reach the fully converged solution with an order of magnitude of improvement in the total computational time with respect to the Jacobi-based local accelerated lambda iteration method.

  7. Incidence of Leukoencephalopathy After Whole-Brain Radiation Therapy for Brain Metastases

    International Nuclear Information System (INIS)

    Ebi, Junko; Sato, Hisashi; Nakajima, Masaru; Shishido, Fumio

    2013-01-01

    Purpose: To evaluate the incidence of leukoencephalopathy after whole-brain radiation therapy (WBRT) in patients with brain metastases. Methods and Materials: We retrospectively reviewed 111 patients who underwent WBRT for brain metastases from April 2001 through March 2008 and had evaluable computed tomography (CT) and/or magnetic resonance imaging (MRI) at least 1 month after completion of WBRT. We evaluated the leukoencephalopathy according to the Common Terminology Criteria for Adverse Events, version 3.0. The patients who had brain tumor recurrence after WBRT were censored at the last follow-up CT or MRI without recurrence. To evaluate the risk factors for leukoencephalopathy, bivariate analysis was performed using a logistic regression analysis adjusted for follow-up time. Factors included in the analysis were age, gender, dose fractionation, 5-fluorouracil, methotrexate, cisplatin, and other chemotherapeutic agents. Results: The median age of the 111 patients was 60.0 years (range, 23-89 years). The median follow-up was 3.8 months (range, 1.0-38.1 months). Leukoencephalopathy developed in 23 of the 111 patients. Grades 1, 2, and 3 were observed in 8, 7, and 8 patients, respectively. The incidence was 34.4% (11 of 32), 42.9% (6 of 14), 66.7% (2 of 3), and 100% (2 of 2) of the patients who were followed up for ≥6, ≥12, ≥24, and ≥36 months, respectively. In the bivariate analysis, older age (≥65 years) was significantly correlated with higher risk of leukoencephalopathy (odds ratio 3.31; 95% confidence interval 1.15-9.50; P=.03). Conclusions: The incidence of leukoencephalopathy after WBRT was 34.4% with ≥6 months follow-up, and increased with longer follow-up. Older age was a significant risk factor. The schedule of WBRT for patients with brain metastases should be carefully determined, especially for favorable patients

  8. A Systematic Overview of Radiation Therapy Effects in Brain Tumours

    International Nuclear Information System (INIS)

    Berg, Gertrud; Blomquist, Erik; Cavallin-Staahl, Eva

    2003-01-01

    A systematic review of radiation therapy trials in several tumour types was performed by The Swedish Council of Technology Assessment in Health Care (SBU). The procedures for evaluation of the scientific literature are described separately. This synthesis of the literature on radiation therapy for brain tumours is based on data from 9 randomized trials and 1 meta-analysis. Moreover, data from 2 prospective studies, 3 retrospective studies and 4 other articles were used. In total, 19 scientific articles are included, involving 4,266 patients. The results were compared with those of a similar overview from 1996 including 11,252 patients. The conclusions reached can be summarized as follows: The conclusion from SBU 129/2 that curative treatment is not available for patients with high-grade malignant glioma (grade III and IV) is still valid. The survival benefit from postoperative radiotherapy compared to supportive care only or chemotherapy is about 3-4 months, as demonstrated in earlier randomized studies. Quality of life is now currently estimated and considered to be of major importance when reporting the outcome of treatment for patients with brain tumours. There is no scientific evidence that radiotherapy using hyper- and hypofractionation leads to longer survival for patients with high-grade malignant glioma than conventional radiotherapy. There is large documentation, but only one randomized study. There is some documentation to support the view that patients with grade IV glioma and poor prognosis can be treated with hypofractionation and with an outcome similar to that after conventional fractionation. A shorter treatment time should be convenient for the patient. Documentation of the benefit of a radiotherapy boost with brachytherapy is limited and no conclusion can be drawn. There is no scientific evidence that radiotherapy prolongs life for patients with low-grade glioma. There are some data supporting that radiotherapy can be used to treat symptoms in

  9. Monkey brain damage from radiation in the therapeutic range

    International Nuclear Information System (INIS)

    Nakagaki, H.; Brunhart, G.; Kemper, T.L.; Caveness, W.F.

    1976-01-01

    Twelve Macaca mulatta monkeys received 200 rads of supervoltage radiation to the whole brain per day, 5 days a week. The course in four monkeys was 4 weeks for a total dose of 4000 rads; in four monkeys, 6 weeks for 6000 rads; and in four monkeys, 8 weeks for 8000 rads. Four unirradiated monkeys served as controls. One from each group, sacrificed at 6 and 12 months from start of irradiation, is reported here. The results from 4000 rads were negligible; those from 8000 rads, profound, with gross brain destruction. The results from 6000 rads, within the therapeutic range, included at 6 months punctate necrotic lesions, 1 mm or less, widely scattered but with a predilection for the forebrain white matter. The reaction to these lesions ranged from an early macrophage response to calcification. Some were accompanied by focal edema. There were occasional examples of vascular endothelial proliferation. In addition, there were patches of dilated capillaries or telangiectasia. Twelve months after 6000 rads there were a few mineralized lesions and innumerable minute deposits of calcium and iron. A more active process was suggested by widely disseminated areas of telangiectasia, 6 to 12 mm in extent. The clinical course from this exposure included papilledema from the third to the sixth month and depressed visual evoked response accompanied by delta activity in the electroencephalogram from the sixth to the twelfth month

  10. Radiation exposure distribution in patients undergoing CT brain scans

    International Nuclear Information System (INIS)

    Yang Zhanshan; Feng Dinghua; Chang Zichi; Li Shijun

    1989-12-01

    The distribution of surface exposures in patients undergoing single and multiple computerized tomographic brain scans with Hitachi CT-W500 was measured by LiF(Mg, Ti) thermoluminescent dosimetry. It was found that there was no significant difference in the sufrace exposures from different scanning slices. However, the exposure doses at different scanning angles around the head were different significantly. The reference point of the maximum surface exposure was at the temporal part of the head. the maximum surface exposure was at 1.65 x 10 -3 C·kg -1 while the average exposure was 1.55 x 10 -3 C·kg -1 . The ratio of the average dose resulting from nine scans to that from a single scan was 1.3, and the surface exposure contribution of scattered radiation was computed. At the same time the radiation doses to eyes, thyroid, chest and gonads of patiens at corresponding position were also measured and were compared with those from CT cranial scans in children and skull radiographic procedures respectively

  11. Imaging modalities in radiation treatment planning of brain tumors

    International Nuclear Information System (INIS)

    Georgiev, D.

    2009-01-01

    The radiation therapy is a standard treatment after surgery for most of malignant and some of benignant brain tumors. The restriction in acquiring local tumor control is an inability in realization of high dose without causing radiation necrosis in irradiated area and sparing normal tissues. The development of imaging modalities during the last years is responsible for better treatment results and lower early and late toxicity. Essential is the role of image methods not only in the diagnosis and also in the precise anatomical (during last years also functional) localisation, spreading of the tumor, treatment planning process and the effects of the treatment. Target delineation is one of the great geometrical uncertainties in the treatment planning process. Early studies on the use of CT in treatment planning documented that tumor coverage without CT was clearly inadequate in 20% of the patients and marginal in another 27 %. The image fusion of CT, MBI and PET and also the use of contrast materia helps to get over those restrictions. The use of contrast material enhances the signal in 10 % of the patients with glioblastoma multiform and in a higher percentage of the patients with low-grade gliomas

  12. Modeling and optimization aspects of radiation induced grafting of 4-vinylpyridene onto partially fluorinated films

    International Nuclear Information System (INIS)

    Nasef, Mohamed Mahmoud; Ahmad Ali, Amgad; Saidi, Hamdani; Ahmad, Arshad

    2014-01-01

    Modeling and optimization aspects of radiation induced grafting (RIG) of 4-vinylpyridine (4-VP) onto partially fluorinated polymers such as poly(ethylene-co-tetrafluoroethene) (ETFE) and poly(vinylidene fluoride) (PVDF) films were comparatively investigated using response surface method (RSM). The effects of independent parameters: absorbed dose, monomer concentration, grafting time and reaction temperature on the response, grafting yield (GY) were correlated through two quadratic models. The results of this work confirm that RSM is a reliable tool not only for optimization of the reaction parameters and prediction of GY in RIG processes, but also for the reduction of the number of the experiments, monomer consumption and absorbed dose leading to an improvement of the overall reaction cost. - Highlights: • Comparative study of radiation induced grafting of 4-VP onto PVDF and ETFE films. • Optimization of reaction parameters for both grafting systems was made using RSM. • Single factor design for both grafting systems was used as a reference. • Two quadratic regression models were developed for prediction of grafting yield. • RSM is an effective tool for handling grafting reactions under different conditions

  13. Influence of radiation-induced apoptosis on development brain in molecular regulation

    International Nuclear Information System (INIS)

    Gu Guixiong

    2000-01-01

    An outline of current status on the influence of radiation on the development brain was given. Some genes as immediate early gene, Bcl-2 family, p53, heat shock protein and AT gene play an important regulation role in ionizing radiation-induced development brain cells apoptosis. And such biological factor as nerve growth factor, interleukin-1, tumor necrosis factor, basic fibroblast growth factor, transforming growth factor and so on have a vital protection function against ionizing radiation-induced cells apoptosis

  14. Partial Breast Radiation Therapy With Proton Beam: 5-Year Results With Cosmetic Outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Bush, David A., E-mail: dbush@llu.edu [Department of Radiation Oncology, Loma Linda University Medical Center, Loma Linda, California (United States); Do, Sharon [Department of Radiation Oncology, Loma Linda University Medical Center, Loma Linda, California (United States); Lum, Sharon; Garberoglio, Carlos [Department of Surgical Oncology, Loma Linda University Medical Center, Loma Linda, California (United States); Mirshahidi, Hamid [Department of Medical Oncology, Loma Linda University Medical Center, Loma Linda, California (United States); Patyal, Baldev; Grove, Roger; Slater, Jerry D. [Department of Radiation Oncology, Loma Linda University Medical Center, Loma Linda, California (United States)

    2014-11-01

    Purpose: We updated our previous report of a phase 2 trial using proton beam radiation therapy to deliver partial breast irradiation (PBI) in patients with early stage breast cancer. Methods and Materials: Eligible subjects had invasive nonlobular carcinoma with a maximal dimension of 3 cm. Patients underwent partial mastectomy with negative margins; axillary lymph nodes were negative on sampling. Subjects received postoperative proton beam radiation therapy to the surgical bed. The dose delivered was 40 Gy in 10 fractions, once daily over 2 weeks. Multiple fields were treated daily, and skin-sparing techniques were used. Following treatment, patients were evaluated with clinical assessments and annual mammograms to monitor toxicity, tumor recurrence, and cosmesis. Results: One hundred subjects were enrolled and treated. All patients completed the assigned treatment and were available for post-treatment analysis. The median follow-up was 60 months. Patients had a mean age of 63 years; 90% had ductal histology; the average tumor size was 1.3 cm. Actuarial data at 5 years included ipsilateral breast tumor recurrence-free survival of 97% (95% confidence interval: 100%-93%); disease-free survival of 94%; and overall survival of 95%. There were no cases of grade 3 or higher acute skin reactions, and late skin reactions included 7 cases of grade 1 telangiectasia. Patient- and physician-reported cosmesis was good to excellent in 90% of responses, was not changed from baseline measurements, and was well maintained throughout the entire 5-year follow-up period. Conclusions: Proton beam radiation therapy for PBI produced excellent ipsilateral breast recurrence-free survival with minimal toxicity. The treatment proved to be adaptable to all breast sizes and lumpectomy cavity configurations. Cosmetic results appear to be excellent and unchanged from baseline out to 5 years following treatment. Cosmetic results may be improved over those reported with photon

  15. Dosimetric Comparison of Three Dimensional Conformal Radiation Radiotherapy and Helical Tomotherapy Partial Breast Cancer

    International Nuclear Information System (INIS)

    Kim, Dae Woong; Kim, Jong Won; Choi, Yun Kyeong; Kim, Jung Soo; Hwang, Jae Woong; Jeong, Kyeong Sik; Choi, Gye Suk

    2008-01-01

    The goal of radiation treatment is to deliver a prescribed radiation dose to the target volume accurately while minimizing dose to normal tissues. In this paper, we comparing the dose distribution between three dimensional conformal radiation radiotherapy (3D-CRT) and helical tomotherapy (TOMO) plan for partial breast cancer. Twenty patients were included in the study, and plans for two techniques were developed for each patient (left breast:10 patients, right breast:10 patients). For each patient 3D-CRT planning was using pinnacle planning system, inverse plan was made using Tomotherapy Hi-Art system and using the same targets and optimization goals. We comparing the Homogeneity index (HI), Conformity index (CI) and sparing of the organs at risk for dose-volume histogram. Whereas the HI, CI of TOMO was significantly better than the other, 3D-CRT was observed to have significantly poorer HI, CI. The percentage ipsilateral non-PTV breast volume that was delivered 50% of the prescribed dose was 3D-CRT (mean: 40.4%), TOMO (mean: 18.3%). The average ipsilateral lung volume percentage receiving 20% of the PD was 3D-CRT (mean: 4.8%), TOMO (mean: 14.2), concerning the average heart volume receiving 20% and 10% of the PD during treatment of left breast cancer 3D-CRT (mean: 1.6%, 3.0%), TOMO (mean: 9.7%, 26.3%) In summary, 3D-CRT and TOMO techniques were found to have acceptable PTV coverage in our study. However, in TOMO, high conformity to the PTV and effective breast tissue sparing was achieved at the expense of considerable dose exposure to the lung and heart.

  16. The use of gammophos to prevent the delayed radiation injury to brain

    International Nuclear Information System (INIS)

    Shaposhnikova, V.V.; Levitman, M.Kh.; Plotnikova, E.D.; Ehjdus, L.Kh.

    1987-01-01

    The influence of a radioprotector, gammaphos, on the development of delayed vascular changes and necrosis in rat brain following local brain irradiation with 25 Gy was investigated. The radioprotective effect was manifested by both the morphometric parameters of vessels and the survival rate and relative number of animals with gross vascular abnormalities and brain necrosis. There was a causative relationship between the development of gross vascular abnormalities and the occurrence of brain necrosis after exposure to moderate radiation doses

  17. Radiation-induced brain disorders in patients with pituitary tumours

    International Nuclear Information System (INIS)

    Bhansali, A.; Chanda, A.; Dash, R.J.; Banerjee, A.K.; Singh, P.; Sharma, S.C.; Mathuriya, S.N.

    2004-01-01

    Radiation-induced brain disorders (RIBD) are uncommon and they are grave sequelae of conventional radiotherapy. In the present report, we describe the clinical spectrum of RIBD in 11 patients who received post-surgery conventional megavoltage irradiation for residual pituitary tumours. Of these 11 patients (nine men, two women), seven had been treated for non-functioning pituitary tumours and four for somatotropinomas. At the time of irradiation the age of these patients ranged from 30 to 59 years (mean, 39.4 ± 8.3; median, 36) with a follow-up period of 696 months (mean, 18.3 ± 26.4; median, 11). The dose of radiation ranged from 45 to 90 Gy (mean, 51.3 ± 13.4; median, 45), which was given in 1530 fractions (mean, 18.6 ± 5.0; median, 15) with 2.8 ± 0.3 Gy (median, 3) per fraction. The biological effective dose calculated for late complications in these patients ranged from 78.7 to 180 Gy (mean, 99.1 ± 27.5; median, 90). The lag time between tumour irradiation and the onset of symptoms ranged from 6 to 168 months (mean, 46.3 ± 57.0; median, 57). The clinical spectrum of RIBD included new-onset visual abnormalities in five, cerebral radionecrosis in the form of altered sensorium in four, generalized seizures in four, cognitive dysfunction in five, dementia in three and motor deficits in two patients. Magnetic resonance imaging (MRI)/CT of the brain was suggestive of radionecrosis in eight, cerebral oedema in three, cerebral atrophy in two and second neoplasia in one patient. Associated hormone deficiencies at presentation were hypogonadism in eight, hypoadrenalism in six, hypothyroidism in four and diabetes insipidus in one patient. Autopsy in two patients showed primitive neuroectodermal tumour (PNET) and brainstem radionecrosis in one, and a cystic lesion in the left frontal lobe following radionecrosis in the other. We conclude that RIBD have distinctive but varying clinical and radiological presentations. Diabetes insipidus and PNET as a second neoplastic

  18. Whole brain radiation therapy (WBRT) alone versus WBRT and radiosurgery for the treatment of brain metastases.

    Science.gov (United States)

    Patil, Chirag G; Pricola, Katie; Sarmiento, J Manuel; Garg, Sachin K; Bryant, Andrew; Black, Keith L

    2017-09-25

    Historically, whole brain radiation therapy (WBRT) has been the main treatment for brain metastases. Stereotactic radiosurgery (SRS) delivers high-dose focused radiation and is being increasingly utilized to treat brain metastases. The benefit of adding SRS to WBRT is unclear. This is an updated version of the original Cochrane Review published in Issue 9, 2012. To assess the efficacy of WBRT plus SRS versus WBRT alone in the treatment of adults with brain metastases. For the original review, in 2009 we searched the following electronic databases: CENTRAL, MEDLINE, Embase, and CancerLit in order to identify trials for inclusion in this review. For the first update the searches were updated in May 2012.For this update, in May 2017 we searched CENTRAL, MEDLINE, and Embase in order to identify trials for inclusion in the review. We restricted the review to randomized controlled trials (RCTs) that compared use of WBRT plus SRS versus WBRT alone for upfront treatment of adults with newly diagnosed metastases (single or multiple) in the brain resulting from any primary, extracranial cancer. We used the generic inverse variance method, random-effects model in Review Manager 5 for the meta-analysis. We identified three studies and one abstract for inclusion but we could only include two studies, with a total of 358 participants in a meta-analysis. This found no difference in overall survival (OS) between the WBRT plus SRS and WBRT alone groups (hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.65 to 1.02; 2 studies, 358 participants; moderate-quality evidence). For participants with one brain metastasis median survival was significantly longer in the WBRT plus SRS group (6.5 months) versus WBRT group (4.9 months; P = 0.04). Participants in the WBRT plus SRS group had decreased local failure compared to participants who received WBRT alone (HR 0.27, 95% CI 0.14 to 0.52; 2 studies, 129 participants; moderate-quality evidence). Furthermore, we observed an improvement in

  19. Scalp Dose Evaluation According Radiation Therapy Technique of Whole Brain Radiation Therapy

    International Nuclear Information System (INIS)

    Jang, Joon Yung; Park, Soo Yun; Kim, Jong Sik; Choi, Byeong Gi; Song, Gi Won

    2011-01-01

    Opposing portal irradiation with helmet field shape that has been given to a patient with brain metastasis can cause excess dose in patient's scalp, resulting in hair loss. For this reason, this study is to quantitatively analyze scalp dose for effective prevention of hair loss by comparing opposing portal irradiation with scalp-shielding shape and tomotherapy designed to protect patient's scalp with conventional radiation therapy. Scalp dose was measured by using three therapies (HELMET, MLC, TOMO) after five thermo-luminescence dosimeters were positioned along center line of frontal lobe by using RANDO Phantom. Scalp dose and change in dose distribution were compared and analyzed with DVH after radiation therapy plan was made by using Radiation Treatment Planning System (Pinnacle3, Philips Medical System, USA) and 6 MV X-ray (Clinac 6EX, VARIAN, USA). When surface dose of scalp by using thermo-luminescence dosimeters was measured, it was revealed that scalp dose decreased by average 87.44% at each point in MLC technique and that scalp dose decreased by average 88.03% at each point in TOMO compared with HELMET field therapy. In addition, when percentage of volume (V95%, V100%, V105% of prescribed dose) was calculated by using Dose Volume Histogram (DVH) in order to evaluate the existence or nonexistence of hotspot in scalp as to three therapies (HELMET, MLC, TOMO), it was revealed that MLC technique and TOMO plan had good dose coverage and did not have hot spot. Reducing hair loss of a patient who receives whole brain radiotherapy treatment can make a contribution to improve life quality of the patient. It is expected that making good use of opposing portal irradiation with scalp-shielding shape and tomotherapy to protect scalp of a patient based on this study will reduce hair loss of a patient.

  20. Scalp Dose Evaluation According Radiation Therapy Technique of Whole Brain Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Joon Yung; Park, Soo Yun; Kim, Jong Sik; Choi, Byeong Gi; Song, Gi Won [Dept. of Radiation Oncology, Samsung Medical Center, Seoul (Korea, Republic of)

    2011-09-15

    Opposing portal irradiation with helmet field shape that has been given to a patient with brain metastasis can cause excess dose in patient's scalp, resulting in hair loss. For this reason, this study is to quantitatively analyze scalp dose for effective prevention of hair loss by comparing opposing portal irradiation with scalp-shielding shape and tomotherapy designed to protect patient's scalp with conventional radiation therapy. Scalp dose was measured by using three therapies (HELMET, MLC, TOMO) after five thermo-luminescence dosimeters were positioned along center line of frontal lobe by using RANDO Phantom. Scalp dose and change in dose distribution were compared and analyzed with DVH after radiation therapy plan was made by using Radiation Treatment Planning System (Pinnacle3, Philips Medical System, USA) and 6 MV X-ray (Clinac 6EX, VARIAN, USA). When surface dose of scalp by using thermo-luminescence dosimeters was measured, it was revealed that scalp dose decreased by average 87.44% at each point in MLC technique and that scalp dose decreased by average 88.03% at each point in TOMO compared with HELMET field therapy. In addition, when percentage of volume (V95%, V100%, V105% of prescribed dose) was calculated by using Dose Volume Histogram (DVH) in order to evaluate the existence or nonexistence of hotspot in scalp as to three therapies (HELMET, MLC, TOMO), it was revealed that MLC technique and TOMO plan had good dose coverage and did not have hot spot. Reducing hair loss of a patient who receives whole brain radiotherapy treatment can make a contribution to improve life quality of the patient. It is expected that making good use of opposing portal irradiation with scalp-shielding shape and tomotherapy to protect scalp of a patient based on this study will reduce hair loss of a patient.

  1. Effect of prophylactic hyperbaric oxygen treatment for radiation-induced brain injury after stereotactic radiosurgery of brain metastases

    International Nuclear Information System (INIS)

    Ohguri, Takayuki; Imada, Hajime; Kohshi, Kiyotaka; Kakeda, Shingo; Ohnari, Norihiro; Morioka, Tomoaki; Nakano, Keita; Konda, Nobuhide; Korogi, Yukunori

    2007-01-01

    Purpose: The purpose of the present study was to evaluate the prophylactic effect of hyperbaric oxygen (HBO) therapy for radiation-induced brain injury in patients with brain metastasis treated with stereotactic radiosurgery (SRS). Methods and Materials: The data of 78 patients presenting with 101 brain metastases treated with SRS between October 1994 and September 2003 were retrospectively analyzed. A total of 32 patients with 47 brain metastases were treated with prophylactic HBO (HBO group), which included all 21 patients who underwent subsequent or prior radiotherapy and 11 patients with common predictors of longer survival, such as inactive extracranial tumors and younger age. The other 46 patients with 54 brain metastases did not undergo HBO (non-HBO group). Radiation-induced brain injuries were divided into two categories, white matter injury (WMI) and radiation necrosis (RN), on the basis of imaging findings. Results: Radiation-induced brain injury occurred in 5 lesions (11%) in the HBO group (2 WMIs and 3 RNs) and in 11 (20%) in the non-HBO group (9 WMIs and 2 RNs). The WMI was less frequent for the HBO group than for the non-HBO group (p = 0.05), although multivariate analysis by logistic regression showed that WMI was not significantly correlated with HBO (p = 0.07). The 1-year actuarial probability of WMI was significantly better for the HBO group (2%) than for the non-HBO group (36%) (p < 0.05). Conclusions: The present study showed a potential value of prophylactic HBO for Radiation-induced WMIs, which justifies further evaluation to confirm its definite benefit

  2. The effect of small radiation doses on the rat spinal cord: the concept of partial tolerance

    International Nuclear Information System (INIS)

    Ang, K.K.; Van Der Kogel, A.J.; Van Der Schueren, E.

    1983-01-01

    To evaluate the tolerance of the rat spinal cord to small radiation doses per fraction, an increasing number of fractions is required for induction of paralysis. The assessment of doses of 1-2 Gy, as used in the clinic, would require that over 100 fractions be given. The validity of replacing part of a fractionated irradiation of the spinal cord by a single large dose has been tested. Fractionated irradiation doses with 18 MeV X rays were followed by a ''top-up'' dose of 15 Gy as a single treatment. This is the fraction size of a treatment with two irradiation doses leading to paralysis in 50% of the animals (ED 50). Fractionated treatments were carried out with 2, 5, 10 and 20 fractions followed by the top-up dose of 15 Gy. the isoeffect curve, as a function of the number of fractions, has the same slope as experiments performed without top-up dose. The results show that the quality and quantity of cellular repair is not modified when part of a multifractionated exposure is replaced by a larger top-dose. An important consequence of this finding is, that in treatments with unequal fraction sizes, the partial tolerances can simply be added. Since a top-up dose can replace a sizable number of irradiation treatments, its application will allow investigations of the extent of sublethal damage repair for fraction sizes as low as 1 Gy

  3. Measurement of Local Partial Pressure of Oxygen in the Brain Tissue under Normoxia and Epilepsy with Phosphorescence Lifetime Microscopy

    Science.gov (United States)

    Zhang, Cong; Bélanger, Samuel; Pouliot, Philippe; Lesage, Frédéric

    2015-01-01

    In this work a method for measuring brain oxygen partial pressure with confocal phosphorescence lifetime microscopy system is reported. When used in conjunction with a dendritic phosphorescent probe, Oxyphor G4, this system enabled minimally invasive measurements of oxygen partial pressure (pO2) in cerebral tissue with high spatial and temporal resolution during 4-AP induced epileptic seizures. Investigating epileptic events, we characterized the spatio-temporal distribution of the "initial dip" in pO2 near the probe injection site and along nearby arterioles. Our results reveal a correlation between the percent change in the pO2 signal during the "initial dip" and the duration of seizure-like activity, which can help localize the epileptic focus and predict the length of seizure. PMID:26305777

  4. Measurement of Local Partial Pressure of Oxygen in the Brain Tissue under Normoxia and Epilepsy with Phosphorescence Lifetime Microscopy.

    Science.gov (United States)

    Zhang, Cong; Bélanger, Samuel; Pouliot, Philippe; Lesage, Frédéric

    2015-01-01

    In this work a method for measuring brain oxygen partial pressure with confocal phosphorescence lifetime microscopy system is reported. When used in conjunction with a dendritic phosphorescent probe, Oxyphor G4, this system enabled minimally invasive measurements of oxygen partial pressure (pO2) in cerebral tissue with high spatial and temporal resolution during 4-AP induced epileptic seizures. Investigating epileptic events, we characterized the spatio-temporal distribution of the "initial dip" in pO2 near the probe injection site and along nearby arterioles. Our results reveal a correlation between the percent change in the pO2 signal during the "initial dip" and the duration of seizure-like activity, which can help localize the epileptic focus and predict the length of seizure.

  5. Pathophysiological Responses in Rat and Mouse Models of Radiation-Induced Brain Injury.

    Science.gov (United States)

    Yang, Lianhong; Yang, Jianhua; Li, Guoqian; Li, Yi; Wu, Rong; Cheng, Jinping; Tang, Yamei

    2017-03-01

    The brain is the major dose-limiting organ in patients undergoing radiotherapy for assorted conditions. Radiation-induced brain injury is common and mainly occurs in patients receiving radiotherapy for malignant head and neck tumors, arteriovenous malformations, or lung cancer-derived brain metastases. Nevertheless, the underlying mechanisms of radiation-induced brain injury are largely unknown. Although many treatment strategies are employed for affected individuals, the effects remain suboptimal. Accordingly, animal models are extremely important for elucidating pathogenic radiation-associated mechanisms and for developing more efficacious therapies. So far, models employing various animal species with different radiation dosages and fractions have been introduced to investigate the prevention, mechanisms, early detection, and management of radiation-induced brain injury. However, these models all have limitations, and none are widely accepted. This review summarizes the animal models currently set forth for studies of radiation-induced brain injury, especially rat and mouse, as well as radiation dosages, dose fractionation, and secondary pathophysiological responses.

  6. Analysis of Selected Photovoltaic Panels Operating Parameters as a Function of Partial Shading and Intensity of Reflected Radiation

    Directory of Open Access Journals (Sweden)

    Bilčík Matúš

    2018-03-01

    Full Text Available Due to expansion of utilisation of photovoltaics in ordinary households, the question arises how this phenomenon affects the electric power of photovoltaic modules. The article deals with the electric power analysis of photovoltaic modules as a function of two very important factors. The first examined factor was partial shading, and the second factor was the intensity of reflected radiation. In order to determine the dependence of module power on the aforementioned parameters, a measurement system under laboratory conditions has been prepared. For identification of the reflected radiation effect on the power of the photovoltaic module, a series of measurements was performed on 7 different surfaces with the same radiation source. It is evident from obtained experimental result that the ratio of reflected irradiation on the solar module power is 1.29%. By simulation of partial shading of photovoltaic module, the decrease of 86.15% in its output power was identified.

  7. Influence of posterior dental arch length on brain activity during chewing in patients with mandibular distal extension removable partial dentures.

    Science.gov (United States)

    Shoi, K; Fueki, K; Usui, N; Taira, M; Wakabayashi, N

    2014-07-01

    It is well known that shortened dental arch decreases masticatory function. However, its potential to change brain activity during mastication is unknown. The present study investigates the effect of a shortened posterior dental arch with mandibular removable partial dentures (RPDs) on brain activity during gum chewing. Eleven subjects with missing mandibular molars (mean age, 66.1 years) on both sides received experimental RPDs with interchangeable artificial molars in a crossover trial design. Brain activity during gum chewing with RPDs containing (full dental arch) and lacking artificial molars (shortened dental arch) was measured using functional magnetic resonance imaging. Additionally, masticatory function was evaluated for each dental arch type. Food comminuting and mixing ability and the perceived chewing ability were significantly lower in subjects with a shortened dental arch than those with a full dental arch (P chewing with the full dental arch occurred in the middle frontal gyrus, primary sensorimotor cortex extending to the pre-central gyrus, supplementary motor area, putamen, insula and cerebellum. However, middle frontal gyrus activation was not observed during gum chewing with the shortened dental arch. These results suggest that shortened dental arch affects human brain activity in the middle frontal gyrus during gum chewing, and the decreased middle frontal gyrus activation may be associated with decreased masticatory function. © 2014 John Wiley & Sons Ltd.

  8. Classification of brain tumor extracts by high resolution ¹H MRS using partial least squares discriminant analysis

    Directory of Open Access Journals (Sweden)

    A.V. Faria

    2011-02-01

    Full Text Available High resolution proton nuclear magnetic resonance spectroscopy (¹H MRS can be used to detect biochemical changes in vitro caused by distinct pathologies. It can reveal distinct metabolic profiles of brain tumors although the accurate analysis and classification of different spectra remains a challenge. In this study, the pattern recognition method partial least squares discriminant analysis (PLS-DA was used to classify 11.7 T ¹H MRS spectra of brain tissue extracts from patients with brain tumors into four classes (high-grade neuroglial, low-grade neuroglial, non-neuroglial, and metastasis and a group of control brain tissue. PLS-DA revealed 9 metabolites as the most important in group differentiation: γ-aminobutyric acid, acetoacetate, alanine, creatine, glutamate/glutamine, glycine, myo-inositol, N-acetylaspartate, and choline compounds. Leave-one-out cross-validation showed that PLS-DA was efficient in group characterization. The metabolic patterns detected can be explained on the basis of previous multimodal studies of tumor metabolism and are consistent with neoplastic cell abnormalities possibly related to high turnover, resistance to apoptosis, osmotic stress and tumor tendency to use alternative energetic pathways such as glycolysis and ketogenesis.

  9. Clinical evaluation of dose-volume-effect relationship in radiation injury of the brain

    International Nuclear Information System (INIS)

    Saito, Mari

    1990-01-01

    Radiation brain injury, including functional disturbances or morphological changes (brain atrophy, periventricular lucencies or ventricular dilatation), were studied by CT in patients with primary intracranial neoplasms who were followed-up for at least 5 months after receiving radiotherapy. Each of 33 patients with medulloblastoma, pinealregion tumor or malignant lymphoma received a total dose of 40-61 Gy by conventional fractionation using a whole brain irradiation field boosted by a localized field. Of these patients, 19 (58%) developed radiation brain injury. It was concluded that the volume-dose was one of the most important factors influencing the development of radiation brain injury. Age at the time of radiotherapy and time of follow-up after the treatment were also considered to be important factors. (author)

  10. Medical exposure to ionising radiation and the risk of brain tumours

    DEFF Research Database (Denmark)

    Blettner, Maria; Schlehofer, Brigitte; Samkange-Zeeb, Florence

    2007-01-01

    BACKGROUND: The role of exposure to low doses of ionising radiation in the aetiology of brain tumours has yet to be clarified. The objective of this study was to investigate the association between medically or occupationally related exposure to ionising radiation and brain tumours. METHODS: We...... used self-reported medical and occupational data collected during the German part of a multinational case-control study on mobile phone use and the risk of brain tumours (Interphone study) for the analyses. RESULTS: For any exposure to medical ionising radiation we found odds ratios (ORs) of 0.63 (95...... regions. CONCLUSION: We did not find any significant increased risk of brain tumours for exposure to medical ionising radiation....

  11. Bevacizumab for the Treatment of Gammaknife Radiosurgery-Induced Brain Radiation Necrosis.

    Science.gov (United States)

    Ma, Yifang; Zheng, Chutian; Feng, Yiping; Xu, Qingsheng

    2017-09-01

    Radiation necrosis is one of the complications of Gammaknife radiosurgery. The traditional treatment of radiation necrosis carries a high risk of failure, Bevacizumab is an antiangiogenic monoclonal antibody against vascular endothelial growth factor, a known mediator of cerebral edema. It can be used to successfully treat brain radiation necrosis. Two patients with a history of small cell lung cancer presented with metastatic disease to the brain. They underwent Gammaknife radiosurgery to brain metastases. Several months later, magnetic resonance imaging showed radiation necrosis with significant surrounding edema. The patients had a poor response to treatment with dexamethasone. They were eventually treated with bevacizumab (5 mg/kg every 2 weeks, 7.5 mg/kg every 3 weeks, respectively), and the treatment resulted in significant clinical and radiographic improvement. Bevacizumab can be successfully used to treat radiation necrosis induced by Gammaknife radiosurgery in patients with cerebral metastases. It is of particular benefit in patients with poor reaction to corticosteroids and other medications.

  12. Adverse radiation effect after stereotactic radiosurgery for brain metastases : incidence, time course, and risk factors

    NARCIS (Netherlands)

    Sneed, Penny K.; Mendez, Joe; Vemer-van den Hoek, Johanna; Seymour, Zachary A.; Ma, Lijun; Molinaro, Annette M.; Fogh, Shannon E.; Nakamura, Jean L.; McDermott, Michael W.

    OBJECT The authors sought to determine the incidence, time course, and risk factors for overall adverse radiation effect (ARE) and symptomatic ARE after stereotactic radiosurgery (SRS) for brain metastases. METHODS All cases of brain metastases treated from 1998 through 2009 with Gamma Knife SRS at

  13. Hot heads and cold brains. Aristotle, Galen and the "radiator theory".

    Science.gov (United States)

    Longo, O

    1996-01-01

    The Author examines two similar theories about the functioning of human brain as a refrigerator: Falk's and Fialkowski's (1990) and Aristotle's (IVth century b.C.). There are surprising, although fortuitous, convergences between the two, with the remarkable difference, however, that Artistotle's doctrine (later severely criticized by Galen) thinks of the brain merely as an organ for the cooling of the body's (the heart's) heat, while according to the modern radiator theory the human brain developed starting as a refrigerator of itself.

  14. A method for measuring brain partial pressure of oxygen in unanesthetized unrestrained subjects: the effect of acute and chronic hypoxia on brain tissue PO(2).

    Science.gov (United States)

    Ortiz-Prado, E; Natah, Siraj; Srinivasan, Sathyanarayanan; Dunn, Jeff F

    2010-11-30

    The level of tissue oxygenation provides information related to the balance between oxygen delivery, oxygen utilization, tissue reactivity and morphology during physiological conditions. Tissue partial pressure of oxygen (PtO(2)) is influenced by the use of anesthesia or restraint. These factors may impact the absolute level of PtO(2). In this study we present a novel fiber optic method to measure brain PtO(2). This method can be used in unanesthetized, unrestrained animals, provides absolute values for PO(2), has a stable calibration, does not consume oxygen and is MRI compatible. Brain PtO(2) was studied during acute hypoxia, as well as before and after 28 days of high altitude acclimatization. A sensor was chronically implanted in the frontal cortex of eight Wistar rats. It is comprised of a fiber optic probe with a tip containing material that fluoresces with an oxygen dependent lifetime. Brain PtO(2) declines by 80% and 76% pre- and post-acclimatization, respectively, when the fraction of inspired oxygen declines from 0.21 to 0.08. In addition, a linear relationship between brain PtO(2) and inspired O(2) levels was demonstrated r(2)=0.98 and r(2)=0.99 (pre- and post-acclimatization). Hypoxia acclimatization resulted in an increase in the overall brain PtO(2) by approximately 35%. This paper demonstrates the use of a novel chronically implanted fiber optic based sensor for measuring absolute PtO(2). It shows a very strong linear relationship in awake animals between inspired O(2) and tissue O(2), and shows that there is a proportional increase in PtO(2) over a range of inspired values after exposure to chronic hypoxia. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Endosulfine, endogenous ligand for the sulphonylurea receptor: isolation from porcine brain and partial structural determination of the alpha form.

    Science.gov (United States)

    Virsolvy-Vergine, A; Salazar, G; Sillard, R; Denoroy, L; Mutt, V; Bataille, D

    1996-02-01

    Anti-diabetic sulphonylureas act via high affinity binding sites coupled to K-ATP channels. Endosulfine, an endogenous ligand for these binding sites, was shown to exist in two molecular forms, alpha and beta, in both the pancreas and the central nervous system. We describe here the isolation, and partial structural characterization of alpha endosulfine derived from porcine brains by means of a series of chromatography runs and gel electrophoresis. Porcine alpha endosulfine is a protein with a molecular mass of 13,196 daltons as determined by mass spectrometry and which is N-terminally blocked. Tryptic digestion followed by separation of the fragments by HPLC and automated Edman degradation yielded a total of 72 amino acids in four partial sequences. Comparison of these sequences with that present in the National Biomedical Research Foundation protein data bank indicated a 82% identity with a 112-amino acid protein with a molecular mass of 12,353 daltons called "cyclic AMP-regulated phosphoprotein-19', isolated from the bovine brain as a substrate for protein kinase A.

  16. A case of lung adenocarcinoma with multiple intracranial hemorrhages of brain metastases after whole-brain radiation therapy

    International Nuclear Information System (INIS)

    Nakamichi, Shinji; Hirano, Satoshi; Asao, Tetsuhiko; Takeda, Yuichiro; Sugiyama, Haruhito; Kobayashi, Nobuyuki

    2011-01-01

    Whole-brain radiation therapy (WBRT) is widely applied in cases of brain metastases of non-small cell lung cancer (NSCLC). However, there are few case reports on hemorrhages of brain metastases occurring after WBRT. A 63-year-old woman was given a diagnosis of stage IV (T4N0M1b) lung adenocarcinoma about 4 years previously, and received chemotherapy regimens and gamma knife radiosurgery. However, her brain metastases exacerbated and she received WBRT in November 2010 and docetaxel monotherapy in December 2010. Two weeks after completing WBRT, she experienced dysarthria and an MRI showed multiple hemorrhages within brain metastases. Over a period of careful observation, these hemorrhages repeatedly alternated between improvement and exacerbation. Radiotherapy for metastatic brain tumors is considered to suppress hemorrhagic events of brain metastases. However, multiple intracranial hemorrhages of brain metastases occurred after WBRT in the present case. The accumulation of further studies of similar cases is necessary to identify the exact mechanism of these hemorrhages. (author)

  17. Radiation risk to critical organ during brain CT

    International Nuclear Information System (INIS)

    Alaraki, N. M. E.

    2012-08-01

    Study was performed to evaluate dose to critical organ for patient undergoing CT brain in modern medical center a total of 61 patient were examined in this study. The data collected from Modern Medical Center for brain. The data collected from Modern Medical Center for brain. The eye lens dose was 31.31 mSv, skin 29.23 mSv, cranium 30.01 mSv, brain 34.50 mSv, mandible 4.39 mSv, thyroid 2.59 mSv. The organ dose value were comparable to the previous studies. (Author)

  18. Skull and cerebrospinal fluid effects on microwave radiation propagation in human brain

    Science.gov (United States)

    Ansari, M. A.; Zarei, M.; Akhlaghipour, N.; Niknam, A. R.

    2017-12-01

    The determination of microwave absorption distribution in the human brain is necessary for the detection of brain tumors using thermo-acoustic imaging and for removing them using hyperthermia treatment. In contrast to ionizing radiation, hyperthermia treatment can be applied to remove tumors inside the brain without the concern of including secondary malignancies, which typically form from the neuronal cells of the septum pellucidum. The aim of this study is to determine the microwave absorption distribution in an adult human brain and to study the effects of skull and cerebrospinal fluid on the propagation of microwave radiation inside the brain. To this end, we simulate the microwave absorption distribution in a realistic adult brain model (Colin 27) using the mesh-based Monte Carlo (MMC) method. This is because in spite of there being other numerical methods, the MMC does not require a large memory, even for complicated geometries, and its algorithm is simple and easy to implement with low computational cost. The brain model is constructed using high-resolution (1 mm isotropic voxel) and low noise magnetic resonance imaging (MRI) scans and its volume contains 181×217×181 voxels, covering the brain completely. Using the MMC method, the radiative transport equation is solved and the absorbed microwave energy distribution in different brain regions is obtained without any fracture or anomaly. The simulation results show that the skull and cerebrospinal fluid guide the microwave radiation and suppress its penetration through deep brain compartments as a shielding factor. These results reveal that the MMC can be used to predict the amount of required energy to increase the temperature inside the tumour during hyperthermia treatment. Our results also show why a deep tumour inside an adult human brain cannot be efficiently treated using hyperthermia treatment. Finally, the accuracy of the presented numerical method is verified using the signal flow graph technique.

  19. Patients with brain metastases from gastrointestinal tract cancer treated with whole brain radiation therapy:Prognostic factors and survival

    Institute of Scientific and Technical Information of China (English)

    Susanne Bartelt; Felix Momm; Christian Weissenberger; Johannes Lutterbach

    2004-01-01

    AIM: To identify the prognostic factors with regard to survival for patients with brain metastasis from primary tumors of the gastrointestinal tract.METHODS: Nine hundred and sixteen patients with brain metastases, treated with whole brain radiation therapy (WBRT) between January 1985 and December 2000 at the Department of Radiation Oncology, University Hospital Freiburg, were analyzed retrospectively.RESULTS: Fifty-seven patients presented with a primary tumor of the gastrointestinal tract (esophagus: n = 0, stomach:n = 10, colorectal: n = 47). Twenty-six patients had a solitary brain metastasis, 31 patients presented with multiple brain metastases. Surgical resection was performed in 25 patients.WBRTwas applied with daily fractions of 2 Gray (Gy) or 3 Gy to a total dose of 50 Gy or 30 Gy, respectively. The interval between diagnoses of the primary tumors and brain metastases was 22.6 mo vs8.0 mo for patients with primary tumors of the colon/rectum vs other primary tumors,respectively (P<0.01, log-rank). Median overall survival for all patients with brain metastases (n = 916) was 3.4 mo and 3.2 mo for patients with gastrointestinal neoplasms.Patients with gastrointestinal primary tumors presented significantly more often with a solitary brain metastasis than patients with other primary tumors (P<0.05, log-rank). In patients with gastrointestinal neoplasms (n = 57), the median overall survival was 5.8 mo for patients with solitary brain metastasis vs 2.7 mo for patients with multiple brain metastases (P<0.01, log-rank). The median overall survival for patients with a Karnofsky performance status (KPS) ≥70was 5.5 mo vs2.1 mo for patients with KPS <70 (P<0.01,log-rank). At multivariate analysis (Cox Model) the performance status and the number of brain metastases were identified as independent prognostic factors for overall survival.CONCLUSION: Brain metastases occur late in the course of gastrointestinal tumors. Pretherapeutic variables like KPS and the

  20. A Case of Moyamoya-like Vessels with History of Brain Radiation

    Directory of Open Access Journals (Sweden)

    M Zare

    2004-08-01

    Full Text Available A 13 years old boy underwenta surgical operation of craniopharyngioma which followed by postoperative radiation therapy. Eighteen monthes later he was admitted to the neurological ward due to sudden sensory aphasia. Brain CT showed infarction of left hemisphere. Since no other predisposing factor was present, the cause of stroke in this patient can be related to Moyamoya - like disease after radiation. Keywords: Moyamoya, Stroke, Aphasia, Craniopharyngioma, Radiation Therapy

  1. Prenatal exposure to atomic radiation and brain damage

    International Nuclear Information System (INIS)

    Otake, Masanori; Yoshimaru, Hiroshi; Schull, W.J.

    1989-01-01

    The purpose of this study was threefold: to evaluate the risks to the developing human embryonic and fetal brain of exposure to ionizing radiation using the new DS86 doses; to compare the estimate of risk so derived with those based on the earlier T65DR doses; and to present the evidence bearing on a threshold in the low dose region under the two systems of dosimetry, especially for the data on clinically recognized severe mental retardation (SMR) and seizure. Regarding dose-related SMR, IQ scores, school performance and seizures, there was a high temporal correspondence between the T65DR and DS86 dosimetry systems. A linear no-threshold model with both dosimetry systems also revealed that a significant increase in SMR was observed when the subjects were exposed in the uterus during the periods both 8-15 and 16-25 weeks after fertilization. A threshold in the low dose region was not suggested with the T65DR fetal absorbed doses, but suggested with the DS86 uterine absorbed doses. However, the location or even the existence of a threshold during both periods after fertilization was difficult to demonstrate statistically with the DS86 uterine absorbed doses. When two probable nonradiation-related cases of Down's syndrome were excluded, a threshold with a lower bound was suggested to be observed in the 0.10-0.20 Gy region. Both dosimetries indicated a threshold in the dose-response function for mental retardation in the 16-25 week period, probably within the range from 0.23 to 0.70 Gy. The seizure data provided no persuasive evidence of a threshold during the 8-15 week period after fertilization; the 95% lower bound of the estimate of the threshold included zero. Finally, although the mean IQ scores and the mean school performances in the low dose region were similar to the values in the control group, particularly with doses under 0.10 Gy, evidence for a threshold is not compelling. (N.K.)

  2. Evaluating Changes to Blood-Brain Barrier Integrity in Brain Metastasis over Time and after Radiation Treatment

    Directory of Open Access Journals (Sweden)

    Donna H. Murrell

    2016-06-01

    Full Text Available INTRODUCTION: The incidence of brain metastasis due to breast cancer is increasing, and prognosis is poor. Treatment is challenging because the blood-brain barrier (BBB limits efficacy of systemic therapies. In this work, we develop a clinically relevant whole brain radiotherapy (WBRT plan to investigate the impact of radiation on brain metastasis development and BBB permeability in a murine model. We hypothesize that radiotherapy will decrease tumor burden and increase tumor permeability, which could offer a mechanism to increase drug uptake in brain metastases. METHODS: Contrast-enhanced magnetic resonance imaging (MRI and high-resolution anatomical MRI were used to evaluate BBB integrity associated with brain metastases due to breast cancer in the MDA-MB-231-BR-HER2 model during their natural development. Novel image-guided microirradiation technology was employed to develop WBRT treatment plans and to investigate if this altered brain metastatic growth or permeability. Histology and immunohistochemistry were performed on whole brain slices corresponding with MRI to validate and further investigate radiological findings. RESULTS: Herein, we show successful implementation of microirradiation technology that can deliver WBRT to small animals. We further report that WBRT following diagnosis of brain metastasis can mitigate, but not eliminate, tumor growth in the MDA-MB-231-BR-HER2 model. Moreover, radiotherapy did not impact BBB permeability associated with metastases. CONCLUSIONS: Clinically relevant WBRT is not curative when delivered after MRI-detectable tumors have developed in this model. A dose of 20 Gy in 2 fractions was not sufficient to increase tumor permeability such that it could be used as a method to increase systemic drug uptake in brain metastasis.

  3. The effect of the diazepam to the free radical under the brain radiation injury

    International Nuclear Information System (INIS)

    Huo Hongmei; Wang Chen; Zhang Zhilin

    2007-01-01

    Objective: To study the effect of the diazepam on free radical under in the brain radiation injury in the early stage. Methods: A model of whole brain radiation injury in wakefulness was established in the Sprague-Dawley rat. Diazepam was given intraperitoneally 30 minutes before radiation. The brain tissue homogenate was prepared respectively while the rats were executed 6 hours, 1 day, 1 week, 1 month after irradiation. The contents of the superoxide dismutase (SOD) and the malondialdehyde (MDA) in the tissue homogenate were measured by chemical colorimetry. Results: Diazepam could increase the vigor of SOD and reduce the MDA contents after irradiated. Conclusions: Diazepam has certain neuroprotection effect on radiation injury and decreasing the level of the free radicals. (authors)

  4. Detection of radiation brain injury of malignant glioma by 1H-MRS

    International Nuclear Information System (INIS)

    Zhang Mao; Jin Haiguo; Sun Shuquan; Bu Mingwei; Su Qingxiu; Liu Guigang; Sun Baosheng

    2011-01-01

    Objective: Using proton magnetic resonance spectroscopy ( 1 H-MRS) method, to evaluate the difference of radiation brain injury between volumetric modulated arc therapy (VMAT) and three-dimensional conformal radiation therapy (3DCRT) in patients with postoperative glioma after radiation therapy. Methods: 24 patients with malignant glioma (WHOII-IV grade glioma) confirmed with clinical surgery were selected, among them 12 patients were treated with VMAT technique, and another 12 patients with 3DCRT technique, all received DT60-66GY/30-33F dose prescriptions. 1 H-MRS examination was performed to analyze the change of metabolites in the brain tissues of region of interest (ROI) before and after radiotherapy,and the ratios of NAA/ Cr, Cho / Cr, NAA / Cho were computed. Results: The dose distribution of VMAT group was superior to 3DCRT group, the NAA/Cr in two groups after radiation were decreased compared with before radiation, there was a statistically difference in NAA/Cr after radiation between two groups (P<0.01). The Cho / Cr and NAA / Cho in two groups were increased compared with before radiation;after radiation, only NAA/Cho had a statistical difference between two groups (P<0.01). Conclusion: VMAT technique is superior to 3DCTR to reduce radiation brain injury in patients with postoperative glioma. (authors)

  5. Interactive dualism as a partial solution to the mind-brain problem for psychiatry.

    Science.gov (United States)

    McLaren, N

    2006-01-01

    With the collapse of the psychoanalytic and the behaviorist models, and the failure of reductive biologism to account for mental life, psychiatry has been searching for a broad, integrative theory on which to base daily practice. The most recent attempt at such a model, Engel's 'biopsychosocial model', has been shown to be devoid of any scientific content, meaning that psychiatry, alone among the medical disciplines, has no recognised scientific basis. It is no coincidence that psychiatry is constantly under attack from all quarters. In order to develop, the discipline requires an integrative and interactive model which can take account of both the mental and the physical dimensions of human life, yet still remain within the materialist scientific ethos. This paper proposes an entirely new model of mind based in Chalmers' 'interactive dualism' which satisfies those needs. It attributes the causation of all behaviour to mental life, but proposes a split in the nature of mentality such that mind becomes a composite function with two, profoundly different aspects. Causation is assigned to a fast, inaccessible cognitive realm operating within the brain machinery while conscious experience is seen as the outcome of a higher order level of brain processing. The particular value of this model is that it immediately offers a practical solution to the mind-brain problem in that, while all information-processing takes place in the mental realm, it is not in the same order of abstraction as perception. This leads to a model of rational interaction which acknowledges both psyche and soma. It can fill the gap left by the demise of Engel's empty 'biopsychosocial model'.

  6. Dosimetric analysis of the alopecia preventing effect of hippocampus sparing whole brain radiation therapy

    International Nuclear Information System (INIS)

    Mahadevan, Anand; Sampson, Carrie; LaRosa, Salvatore; Floyd, Scott R.; Wong, Eric T.; Uhlmann, Erik J.; Sengupta, Soma; Kasper, Ekkehard M.

    2015-01-01

    Whole brain radiation therapy (WBRT) is widely used for the treatment of brain metastases. Cognitive decline and alopecia are recognized adverse effects of WBRT. Recently hippocampus sparing whole brain radiation therapy (HS-WBRT) has been shown to reduce the incidence of memory loss. In this study, we found that multi-field intensity modulated radiation therapy (IMRT), with strict constraints to the brain parenchyma and to the hippocampus, reduces follicular scalp dose and prevents alopecia. Suitable patients befitting the inclusion criteria of the RTOG 0933 trial received Hippocampus sparing whole brain radiation. On follow up, they were noticed to have full scalp hair preservation. 5 mm thickness of follicle bearing scalp in the radiation field was outlined in the planning CT scans. Conventional opposed lateral WBRT radiation fields were applied to these patient-specific image sets and planned with the same nominal dose of 30 Gy in 10 fractions. The mean and maximum dose to follicle bearing skin and Dose Volume Histogram (DVH) data were analyzed for conventional and HS-WBRT. Paired t-test was used to compare the means. All six patients had fully preserved scalp hair and remained clinically cognitively intact 1–3 months after HS-WBRT. Compared to conventional WBRT, in addition to the intended sparing of the Hippocampus, HS-WBRT delivered significantly lower mean dose (22.42 cGy vs. 16.33 cGy, p < 0.0001), V 24 (9 cc vs. 44 cc, p < 0.0000) and V 30 (9 cc vs. 0.096 cc, p = 0.0106) to follicle hair bearing scalp and prevented alopecia. There were no recurrences in the Hippocampus area. HS-WBRT, with an 11-field set up as described, while attempting to conserve hippocampus radiation and maintain radiation dose to brain inadvertently spares follicle-bearing scalp and prevents alopecia

  7. Partial IGF-1 deficiency induces brain oxidative damage and edema, which are ameliorated by replacement therapy.

    Science.gov (United States)

    Puche, Juan E; Muñoz, Úrsula; García-Magariño, Mariano; Sádaba, María C; Castilla-Cortázar, Inma

    2016-01-01

    Insulin-like growth factor 1 (IGF-1) induces multiple cytoprotective effects on every tissue, including the brain. Since the mechanisms by which IGF-1 produces neuroprotection are not fully understood, the aim of this work was to delve into the underlying mechanisms. IGF-1 deficient mice (Hz) were compared with wild type (WT) and Hz mice treated with low doses of IGF-1 (2 µg/100 g body weight/day) for 10 days (Hz + IGF). Gene expression, quantitative PCR, histology, and magnetic resonance imaging were performed in the three groups. IGF-1 deficiency induced increased oxidative damage determined by markers of lipid peroxidation and hypoxia, as well as gene expression of heat shock proteins, antioxidant enzymes, and molecules involved in inflammation, apoptosis, and mitochondrial protection. These changes correlated with edema and learning impairment in Hz mice. IGF-1 therapy improved all these alterations. In conclusion, IGF-1 deficiency is responsible for increased brain oxidative damage, edema, and impaired learning and memory capabilities which are rescued by IGF-1 replacement therapy. © 2016 International Union of Biochemistry and Molecular Biology.

  8. Influence of oxygen, partial vacuum, temperature and relative humidity combined with gamma radiation on the mosquito, culex pipiens complex L

    International Nuclear Information System (INIS)

    Abdel-rahman, A.M.; Wakid, A.M.; Hafez, M.; Hafez, M.K.

    1992-01-01

    Treatment of pupae of culex pipiens L. With gamma radiation only (60 Gy) caused 47-57.83% decrease in adult emergence. Treatment with oxygen or partial vacuum (0.1 torr) for one hour caused insignificant decrease in adult emergence. This decrease became significant when the exposure time was prolonged to two hours. Exposure of pupae to 10 degree C for one or two hours or to 31% R.H. for 3 hours caused highly significant decrease in adult emergence. When radiation was combined with any of the factors applied, a pronounced decrease in adult emergence was recorded, especially when combined with 31% R.H. for 3 hours. In all treatments, females lived longer than males. Exposure of pupae to oxygen gas or 31% R.H. Only, prolonged the life span of the produced adults, while exposure to radiation, partial vacuum or low temperature only shortened it. This effect was also observed when gamma radiation was combined with these two factors. 4 fig.,1 tab

  9. The effect of perinatal 60Co gamma radiation on brain weight in beagles

    International Nuclear Information System (INIS)

    Hamilton, B.F.; Benjamin, S.A.; Angleton, G.M.; Lee, A.C.

    1989-01-01

    Beagle dogs were given single, whole-body 60 Co gamma-radiation exposures at one of three prenatal (8, 28, or 55 days postcoitus) or three postnatal (2, 70, or 365 days postpartum) ages to evaluate the relative radiosensitivity of various stages of brain development. A total of 387 dogs received mean doses ranging from 0.16 to 3.83 Gy, and 120 dogs were sham-irradiated. Groups of dogs were sacrificed at preselected times from 70 days to 11 years of age. Brain weight decreased significantly with increasing dose in dogs irradiated at 28 or 55 days postcoitus or at 2 days postpartum. Irradiations at 28 days postcoitus were dramatically more effective in causing a reduction in brain weight than those at 55 days postcoitus or 2 days postpartum. Among dogs given 1.0 Gy or more and followed for up to 4 years, there was a radiation effect evident at all three sensitive exposure ages. Among dogs given lower doses and followed for up to 11 years, there was a significant decrease in brain weight in dogs given 0.80-0.88 Gy at 28 days postcoitus. All decreases in brain weight were present after normalization for radiation-induced reductions in skeletal (body) size. No specific morphologic changes were noted in the brains which showed the radiation-related reductions in size

  10. Disordered redox metabolism of brain cells in rats exposed to low doses of ionizing radiation or UHF electromagnetic radiation.

    Science.gov (United States)

    Burlaka, A P; Druzhyna, M O; Vovk, A V; Lukin, S М

    2016-12-01

    To investigate the changes of redox-state of mammalian brain cells as the critical factor of initiation and formation of radiation damage of biological structures in setting of continuous exposure to low doses of ionizing radiation or fractionated ultra high frequency electromagnetic radiation (UHF EMR) at non-thermal levels. The influence of low-intensity ionizing radiation was studied on outbred female rats kept for 1.5 years in the Chernobyl accident zone. The effects of total EMR in the UHF band of non-thermal spectrum were investigated on Wistar rats. The rate of formation of superoxide radicals and the rate of NO synthesis in mitochondria were determined by the EPR. After exposure to ionizing or UHF radiation, the levels of ubisemiquinone in brain tissue of rats decreased by 3 and 1.8 times, respectively. The content of NO-FeS-protein complexes in both groups increased significantly (р < 0.05). In the conditions of ionizing or EMR the rates of superoxide radical generation in electron-transport chain of brain cell mitochondria increased by 1.5- and 2-fold, respectively (р < 0.05). In brain tissue of rats kept in the Chernobyl zone, significant increase of NO content was registered; similar effect was observed in rats treated with UHFR (р < 0.05). The detected changes in the electron transport chain of mitochondria of brain cells upon low-intensity irradiation or UHF EMR cause the metabolic reprogramming of cell mitochondria that increases the rate of superoxide radical generation and nitric oxide, which may initiate the development of neurodegenerative diseases and cancer. This article is part of a Special Issue entitled "The Chornobyl Nuclear Accident: Thirty Years After".

  11. A treatment planning study comparing whole breast radiation therapy against conformal, IMRT and tomotherapy for accelerated partial breast irradiation

    International Nuclear Information System (INIS)

    Oliver, Mike; Chen, Jeff; Wong, Eugene; Van Dyk, Jake; Perera, Francisco

    2007-01-01

    Purpose and background: Conventional early breast cancer treatment consists of a lumpectomy followed by whole breast radiation therapy. Accelerated partial breast irradiation (APBI) is an investigational approach to post-lumpectomy radiation for early breast cancer. The purpose of this study is to compare four external beam APBI techniques, including tomotherapy, with conventional whole breast irradiation for their radiation conformity index, dose homogeneity index, and dose to organs at risk. Methods and materials: Small-field tangents, three-dimensional conformal radiation therapy, intensity-modulated radiation therapy and helical tomotherapy were compared for each of 15 patients (7 right, 8 left). One radiation conformity and two dose homogeneity indices were used to evaluate the dose to the target. The mean dose to organs at risk was also evaluated. Results: All proposed APBI techniques improved the conformity index significantly over whole breast tangents while maintaining dose homogeneity and without a significant increase in dose to organs at risk. Conclusion: The four-field IMRT plan produced the best dosimetric results; however this technique would require appropriate respiratory motion management. An alternative would be to use a four-field conformal technique that is less sensitive to the effects of respiratory motion

  12. Ionizing radiation alters the properties of sodium channels in rat brain synaptosomes

    Energy Technology Data Exchange (ETDEWEB)

    Mullin, M J; Hunt, W A; Harris, R A

    1986-08-01

    The effect of ionizing radiation on neuronal membrane function was assessed by measurement of neurotoxin-stimulated /sup 22/Na/sup +/ uptake by rat brain synaptosomes. High-energy electrons and gamma photons were equally effective in reducing the maximal uptake of /sup 22/Na/sup +/ with no significant change in the affinity of veratridine for its binding site in the channel. Ionizing radiation reduced the veratridine-stimulated uptake at the earliest times measured (3 and 5 s), when the rate of uptake was greatest. Batrachotoxin-stimulated /sup 22/Na/sup +/ uptake was less sensitive to inhibition by radiation. The binding of (/sup 3/H)saxitoxin to its receptor in the sodium channel was unaffected by exposure to ionizing radiation. The effect of ionizing radiation on the lipid order of rat brain synaptic plasma membranes was measured by the fluorescence polarization of the molecular probes 1,6-diphenyl-1,3,5-hexatriene and 1-(4-(trimethylammonium)phenyl)-6-phenyl-1,3,5-hexatriene. A dose of radiation that reduced the veratridine-stimulated uptake of /sup 22/Na/sup +/ had no effect on the fluorescence polarization of either probe. These results demonstrate an inhibitory effect of ionizing radiation on the voltage-sensitive sodium channels in rat brain synaptosomes. This effect of radiation is not dependent on changes in the order of membrane lipids.

  13. Solubilization, partial purification, and reconstitution of glutamate- and N-methyl-D-aspartate-activated cation channels from brain synaptic membranes

    International Nuclear Information System (INIS)

    Ly, A.M.; Michaelis, E.K.

    1991-01-01

    L-Glutamate-activated cation channel proteins from rat brain synaptic membranes were solubilized, partially purified, and reconstituted into liposomes. Optimal conditions for solubilization and reconstitution included treatment of the membranes with nonionic detergents in the presence of neutral phospholipids plus glycerol. Quench-flow procedures were developed to characterize the rapid kinetics of ion flux induced by receptor agonists. [ 14 C]Methylamine, a cation that permeates through the open channel of both vertebrate and invertebrate glutamate receptors, was used to measure the activity of glutamate receptor-ion channel complexes in reconstituted liposomes. L-Glutamate caused an increase in the rate of [ 14 C]methylamine influx into liposomes reconstituted with either solubilized membrane proteins or partially purified glutamate-binding proteins. Of the major glutamate receptor agonists, only N-methyl-D-aspartate activated cation fluxes in liposomes reconstituted with glutamate-binding proteins. In liposomes reconstituted with glutamate-binding proteins, N-methyl-D-aspartate- or glutamate-induced influx of NA + led to a transient increase in the influx of the lipid-permeable anion probe S 14 CN - . These results indicate the functional reconstitution of N-methyl-D-aspartate-sensitive glutamate receptors and the role of the ∼69-kDa protein in the function of these ion channels

  14. Reduction in radiation-induced brain injury by use of pentobarbital or lidocaine protection

    International Nuclear Information System (INIS)

    Oldfield, E.H.; Friedman, R.; Kinsella, T.; Moquin, R.; Olson, J.J.; Orr, K.; DeLuca, A.M.

    1990-01-01

    To determine if barbiturates would protect brain at high doses of radiation, survival rates in rats that received whole-brain x-irradiation during pentobarbital- or lidocaine-induced anesthesia were compared with those of control animals that received no medication and of animals anesthetized with ketamine. The animals were shielded so that respiratory and digestive tissues would not be damaged by the radiation. Survival rates in rats that received whole-brain irradiation as a single 7500-rad dose under pentobarbital- or lidocaine-induced anesthesia was increased from between from 0% and 20% to between 45% and 69% over the 40 days of observation compared with the other two groups (p less than 0.007). Ketamine anesthesia provided no protection. There were no notable differential effects upon non-neural tissues, suggesting that pentobarbital afforded protection through modulation of ambient neural activity during radiation exposure. Neural suppression during high-dose cranial irradiation protects brain from acute and early delayed radiation injury. Further development and application of this knowledge may reduce the incidence of radiation toxicity of the central nervous system (CNS) and may permit the safe use of otherwise unsafe doses of radiation in patients with CNS neoplasms

  15. Computational Modeling of Medical Images of Brain Tumor Patients for Optimized Radiation Therapy Planning

    DEFF Research Database (Denmark)

    Agn, Mikael

    In brain tumor radiation therapy, the aim is to maximize the delivered radiation dose to the targeted tumor and at the same time minimize the dose to sensitive healthy structures – so-called organs-at-risk (OARs). When planning a radiation therapy session, the tumor and the OARs therefore need...... to be delineated on medical images of the patient’s head, to be able to optimize a radiation dose plan. In clinical practice, the delineation is performed manually with limited assistance from automatic procedures, which is both time-consuming and typically suffers from poor reproducibility. There is, therefore...

  16. The role of stereotactic radiation therapy and whole-brain radiotherapy in the treatment of multiple brain metastases

    International Nuclear Information System (INIS)

    Chen Xiujun; Xiao Jianping; Li Xiangpan; Jiang Xuesong; Zhang Ye; Xu Yingjie; Dai Jianrong; Li Yexiong

    2012-01-01

    Objective: To summarize the results of stereotactic radiation therapy (SRT) with or without whole-brain radiotherapy (WBRT) in the treatment of multiple brain metastasis. Methods: From May 1995 to April 2010, totally 98 newly diagnosed multiple (2 - 13 lesions) brain metastases patients were treated in our centre. Forty-four patients were treated with SRT alone and 54 with SRT + WBRT. Dose fractionation schemes were 15 -26 Gy in 1 fraction or 24.0 -52.5 Gy in 2 - 15 fractions with 3.5 - 12.0 Gy per fraction, depending on the tumor volume, location, and history of prior irradiation. Kaplan-Meier and Cox proportional hazards regression analyses were used for survival analysis. The median age of the whole group was 55 years. The survival time was calculated from the date of radiation treatment to the day of death by any cause. Results: The median follow-up time for the whole group was 12 months, and the follow-up rate was 100%. The median overall survival time was 13.5 months for the whole group, there was no difference between SRT alone group and SRT + WBRT group (13.0 months vs. 13.5 months, χ 2 =0.31, P =0.578). The Karnofsky Performance Score (KPS) at the time of treatment (χ 2 =6.25, P =0.012), the interval between the diagnosis of the primary tumor and brain metastases (χ 2 =7.34, P =0.025) and the status of extracranial metastases (χ 2 =4.20, P =0.040) were independent prognosis factors for survival in multivariate analyses. Conclusions: Stereotactic radiation therapy is an effective and alternative treatment choice for multiple brain metastases. (authors)

  17. Inhibitory effect of MgSO4 on calcium overload after radiation-induced brain injuries

    International Nuclear Information System (INIS)

    Tu Yu; Zhou Yuying; Wang Lili

    2005-01-01

    Objective: To explore the neuroprotective effect of magnesium sulfate (MgSO 4 ) on radiation-induced acute brain injuries. Methods: A total of 60 mature Sprague-Dawley rats were randomly divided into 3 groups: blank control group, experimental control group and experimental therapy group. The whole brain of SD rats of experimental control group and experimental therapy group was irradiated to a dose of 20 Gy using 6 MeV electrons. Magnesium sulfate was injected intraperitoneally into the rats of experimental therapy group before and after irradiation for five times. At different time points (24 h, 7 days, 14 days, 30 days after irradiation), the brain tissue was taken. Plasma direct reading spectrography was used to measure the contents of Ca 2+ , Mg 2+ in brain tissue, and the percentage of brain water content was calculated with the wet-dry weight formula. Results: Compared with the blank control group, the percentage of brain water and content of Ca 2+ in brain of the experimental control group increased markedly (P 2+ decreased significantly (P 2+ in brain of the experimental therapy group were significantly lower than those of the experimental control group (P<0.05). Conclusion: Magnesium sulfate used in the early stage after irradiation can inhibit the calcium overload in rat brain , and attenuate brain edema and injuries. (authors)

  18. Action of mercurials on activity of partially purified soluble protein kinase C from mice brain

    International Nuclear Information System (INIS)

    Inoue, Y.; Saijoh, K.; Sumino, K.

    1988-01-01

    The enzymatic activity of soluble protein kinase C from mice brain was inhibited by mercuric chloride (II) (HgCl 2 ) and organic mercurials, i.e. methyl mercury, phenyl mercury and p-chloromercuribenzoic acid (PCMB). The IC50 was 0.08 μM for HgCl 2 and about 1 μM for organic mercurials. Sulfhydryl blocking reagents such as 5.5'-dithiobis-2-nitrobenzoic acid (DTNB) and N-ethylmaleimide (NEM) were less potent but nevertheless inhibited the enzymic activity of protein kinase C. The Hill coefficients of HgCl 2 , DTNB and NEM were close to unity whereas the values for organic mercurials were 1.3 to 1.5. The inhibition was of a non-competitive type with respect to Hl histone. 3 H-PDBu binding activity was also inhibited by all of the reagents in a non-competitive manner. Mercurials apparently bind to sulfhydryl groups of protein kinase C to inhibit the enzymatic activity. (author)

  19. Response-driven imaging biomarkers for predicting radiation necrosis of the brain

    International Nuclear Information System (INIS)

    Nazem-Zadeh, Mohammad-Reza; Chapman, Christopher H; Lawrence, Theodore S; Ten Haken, Randall K; Tsien, Christina I; Cao, Yue; Chenevert, Thomas

    2014-01-01

    Radiation necrosis is an uncommon but severe adverse effect of brain radiation therapy (RT). Current predictive models based on radiation dose have limited accuracy. We aimed to identify early individual response biomarkers based upon diffusion tensor (DT) imaging and incorporated them into a response model for prediction of radiation necrosis. Twenty-nine patients with glioblastoma received six weeks of intensity modulated RT and concurrent temozolomide. Patients underwent DT-MRI scans before treatment, at three weeks during RT, and one, three, and six months after RT. Cases with radiation necrosis were classified based on generalized equivalent uniform dose (gEUD) of whole brain and DT index early changes in the corpus callosum and its substructures. Significant covariates were used to develop normal tissue complication probability models using binary logistic regression. Seven patients developed radiation necrosis. Percentage changes of radial diffusivity (RD) in the splenium at three weeks during RT and at six months after RT differed significantly between the patients with and without necrosis (p = 0.05 and p = 0.01). Percentage change of RD at three weeks during RT in the 30 Gy dose–volume of the splenium and brain gEUD combined yielded the best-fit logistic regression model. Our findings indicate that early individual response during the course of RT, assessed by radial diffusivity, has the potential to aid the prediction of delayed radiation necrosis, which could provide guidance in dose-escalation trials. (paper)

  20. Clinical course of brain stroke in the persons exposed to ionizing radiation under the production conditions

    International Nuclear Information System (INIS)

    Bouchmanov, A.

    2000-01-01

    The purpose was to study the risk factors and clinical course of brain strokes in professionally exposed workers being employed in plutonium production in comparison with a control group. The method and materials of study -clinical supervision and clinical database creation on 162 cases of brain stroke (128 males and 34 females) developed among professionally exposed workers. Age of patient varied from 21 to 68 years (in average -51.6 y.). The control group consisted of patients with the same diagnosis, worked on the same enterprise, but non-exposed to radiation. Data on the totally accumulated dose of external gamma radiation were received on the base of the individual dosimeters (from 0.1 cSv to 52 cSv, in average about 13 cSv); the plutonium-239 body content was estimated accordingly to the level of urine radionuclide excretion (from 0.4 kBq to 1.6 kBq, in average about 0.33 kBq). Muscle's hypertinsion and pathological great-toe reflexes in paretic legs and hands, hemianopsia, impressive and ataxic aphasia prevailed in the patients with ischemic brain strokes in system of internal carotid artery, exposed to radiation. The changes of muscle's tension, ataxia and nystagmus were marked more often in the professionals with ischemic brain strokes in system of vertebrobasilar artery. The illness proceeded more easy and with smaller frequency of frustration of consciousness and algesthesia, irrespective of a type ischemic brain strokes in the people exposed to ionizing radiation, than in patients of non-irradiated group. It was found that the arterial hypertension appeared to be the main risk factor for the brain stroke in both groups of patients (in 81.48% and 91.15% of cases). There was no marked differences in significance of risk factors and in main clinical parameters of various types of ischemic brain strokes among the patients professionally exposed to radiation in comparison with a control group. (author)

  1. Whole-brain hippocampal sparing radiation therapy: Volume-modulated arc therapy vs intensity-modulated radiation therapy case study

    International Nuclear Information System (INIS)

    Lee, Katrina; Lenards, Nishele; Holson, Janice

    2016-01-01

    The hippocampus is responsible for memory and cognitive function. An ongoing phase II clinical trial suggests that sparing dose to the hippocampus during whole-brain radiation therapy can help preserve a patient's neurocognitive function. Progressive research and advancements in treatment techniques have made treatment planning more sophisticated but beneficial for patients undergoing treatment. The aim of this study is to evaluate and compare hippocampal sparing whole-brain (HS-WB) radiation therapy treatment planning techniques using volume-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT). We randomly selected 3 patients to compare different treatment techniques that could be used for reducing dose to the hippocampal region. We created 2 treatment plans, a VMAT and an IMRT, from each patient's data set and planned on the Eclipse 11.0 treatment planning system (TPS). A total of 6 plans (3 IMRT and 3 VMAT) were created and evaluated for this case study. The physician contoured the hippocampus as per the Radiation Therapy Oncology Group (RTOG) 0933 protocol atlas. The organs at risk (OR) were contoured and evaluated for the plan comparison, which included the spinal cord, optic chiasm, the right and left eyes, lenses, and optic nerves. Both treatment plans produced adequate coverage on the planning target volume (PTV) while significantly reducing dose to the hippocampal region. The VMAT treatment plans produced a more homogenous dose distribution throughout the PTV while decreasing the maximum point dose to the target. However, both treatment techniques demonstrated hippocampal sparing when irradiating the whole brain.

  2. 99Tcm brain imaging for the assessment of patients with intractable partial epilepsy - our experience

    International Nuclear Information System (INIS)

    Schlicht, S.; Bruns, M.; Booth, R.; Octigan, K.; Karamoskos, P.; Cook, M.; O'Brien, T.

    2000-01-01

    Full text: 99 Tc m - Ethyl Cysteinate Diethylester (ECD) or Bicisate is a new radiopharmaceutical used for the assessment of cerebral perfusion. Unlike 99 Tc m Hexamethylpropylene Amine Oxime ( 99 Tc m - HMPAO) which is unstable and needs to be reconstituted immediately prior to injection, 99 Tc m -ECD is stable for up to eight hours following reconstitution. Therefore, 99 Tc m -ECD does not require mixing just prior to injection and is readily available on a daily inpatient basis to the epilepsy unit, facilitating earlier and faster injections, and the acquisition of true ictal studies. This is particularly important with patients who have extra temporal seizures which are typically brief in duration. 45 patients have undergone 99 Tc m -ECD studies for epilepsy in our department over a period of one year. Image acquisition routinely commences within two hours of injection, and consists of a 360 degree elliptical SPECT using an ADAC Dual Headed Gamma Camera. Patients undergo both ictal and inter ictal SPECT studies, and an MRI. Visual comparison of the ictal, inter ictal and MRI images is performed, as well as subtraction and co-registration. The SISCOM analysis technique is used which allows subtraction of the SPECTs and co registration with MRI. This has the advantage of improved specificity, sensitivity, and accurate anatomical localisation. The results of our experience with 99Tcm-ECD will be presented. In conclusion, we have found that 99 Tc m -ECD is ideally suited for peri-ictal SPECT studies as part of the pre-operative assessment of patients with intractable partial epilepsy. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

  3. PDGFB partial deletion: a new, rare mechanism causing brain calcification with leukoencephalopathy.

    Science.gov (United States)

    Nicolas, Gaël; Rovelet-Lecrux, Anne; Pottier, Cyril; Martinaud, Olivier; Wallon, David; Vernier, Louis; Landemore, Gérard; Chapon, Françoise; Prieto-Morin, Carol; Tournier-Lasserve, Elisabeth; Frébourg, Thierry; Campion, Dominique; Hannequin, Didier

    2014-06-01

    Idiopathic basal ganglia calcification (IBGC) is a progressive cerebral disorder with diverse motor, cognitive, and psychiatric expression. It is inherited as an autosomal dominant trait. Three IBGC-causing genes have been identified in the past 2 years: SLC20A2, PDGFRB, and PDGFB. Biological and genetic evidence showed that loss of function of either SLC20A2 or the PDGFB/PDGFRB pathway was the mechanism underlying calcification in patients with a mutation. Recently, in a study focusing on SLC20A2, a large deletion at this locus was reported. No study has systematically searched for copy number variants (CNV) involving these three genes. We designed a quantitative PCR assay of multiple short fluorescent fragments (QMPSF) to detect CNVs involving one of these three genes in a single assay. Among the 27 unrelated patients from our IBGC case series with no mutation in SLC20A2, PDGFRB, and PDGFB, we identified in one patient a heterozygous partial deletion involving exons 2 to 5 of PDGFB. This patient exhibited both strio-pallido-dentate calcification and white matter hyperintensity of presumed vascular origin, associated with mood disorder, subtle cognitive decline, and gait disorder. We confirmed by RT-PCR experiments that the allele carrying the deletion was transcribed. The resulting cDNA lacks sequence for several critical functional domains of the protein. Intragenic deletion of PDGFB is a new and rare mechanism causing IBGC. CNVs involving the three IBGC-causing genes should be investigated in patients with no point mutation.

  4. Delayed radiation-induced necrosis of the brain stem; A case report

    Energy Technology Data Exchange (ETDEWEB)

    Yukawa, Osamu; Kodama, Yasunori; Kyoda, Jun; Yuki, Kiyoshi; Taniguchi, Eiji; Katayama, Shoichi; Hiroi, Tadashi (National Kure Hospital, Hiroshima (Japan)); Uozumi, Toru

    1993-03-01

    A 46-year-old man had surgery for a mixed glioma of the frontotemporal lobe. Postoperatively he received 50 Gy of irradiation. Sixteen months later he developed left hemiparesis and left facial palsy. MRI revealed lesion brain stem and basal ganglia. Despite chemotherapy and an additional 50 Gy dose, the patient deteriorated. Autopsy revealed a wide spread radiation-induced necrosis in the right cerebral hemisphere, midbrain and pons. In radiation therapy, great care must be taken to protect the normal brain tissue. (author).

  5. Calcification of the bilateral basal ganglia after radiation therapy for childhood brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Osami; Tajika, Yasuhiko; Sakairi, Mitsuhiko; Katahira, Masako; Shimizu, Takashi; Kitamura, Koichi

    1987-12-01

    Calcification of the basal ganglia subsequent to radiation therapy for childhood brain tumors has rarely been reported. Three cases of this calcification subsequent to radiation are presented here. Case 1 is a 7 year-old boy who underwent irradiation of 5000 rads locally for craniopharyngioma at the age of 4 years. Case 2 is a 4 year-old boy who was treated with irradiation of 4500 rads locally for cerebellar medulloblastoma at the age of 1 year. Case 3 is a 15 year-old girl who was treated with irradiation of 5000 rads to the brain and 3000 rads locally for suprasellar germinoma at the age of 11 years. In all these cases, the interval between radiation and evidence of calcification as detected only by CT scan, was more than 3 years and 2 cases are experiencing mild mental retardation. These findings suggest the possibility of long-term complications due to radiation therapy.

  6. Clinical features of brain metastases in breast cancer: an implication for hippocampal-sparing whole-brain radiation therapy

    Directory of Open Access Journals (Sweden)

    Wu S

    2016-12-01

    Full Text Available San-Gang Wu,1,* Jia-Yuan Sun,2,* Qin Tong,3 Feng-Yan Li,2 Zhen-Yu He2 1Department of Radiation Oncology, Xiamen Cancer Hospital, The First Affiliated Hospital of Xiamen University, Xiamen, 2Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou, 3Department of Radiation Oncology, The First Affiliated Hospital of University of South China, Hengyang, People’s Republic of China *These authors contributed equally to this work Objective: The objectives of this study were to describe the distribution of brain metastases (BM in breast cancer patients and investigate the risk factors for perihippocampal metastases (PHM. Patients and methods: Retrospective analysis of the clinicopathological characteristics and patterns of BM was performed. Associations between clinicopathological characteristics and PHM (the hippocampus plus 5 mm margin were evaluated using logistic regression analyses. Results: A total of 1,356 brain metastatic lesions were identified in 192 patients. Patients with 1–3 BM, 4–9 BM, and ≥10 BM accounted for 63.0%, 18.8%, and 18.2%, respectively. There were only 7 (3.6% patients with hippocampal metastases (HM and 14 (7.3% patients with PHM. On logistic regression, the number of BM was an independent risk factor for PHM. Patients with ≥10 BM had a significantly higher risk of PHM compared with those with <10 BM. Breast cancer subtype (BCS was not associated with PHM. The number of BM was significantly correlated with various BCSs. Patients with hormone receptor (HR+/human epidermal growth factor receptor 2 (HER2+, HR-/HER2+, and HR-/HER2- subtypes had a higher probability of ≥10 BM, relative to patients with an HR+/HER2- subtype. Conclusion: Our study suggests that a low incidence of PHM may be acceptable to perform hippocampal-sparing whole-brain radiation therapy for breast cancer patients

  7. Radiation induced late delayed alterations in mice brain after whole body and cranial radiation: a comparative DTI analysis

    International Nuclear Information System (INIS)

    Watve, Apurva; Gupta, Mamta; Trivedi, Richa; Khushu, Subash; Rana, Poonam

    2016-01-01

    Moderate dose of radiation exposure occurs during radiation accidents or radiation therapy induces pathophysiological alterations in CNS that may persist for longer duration. Studies suggest that late delayed injury is irreversible leading to metabolic and cognitive impairment. Our earlier studies have illustrated the varied response of brain at acute and early delayed phase on exposure to cranial and whole body radiation. Hence in continuation with our previous studies, present study focuses on comparative microstructural changes in brain at late delayed phase of radiation injury using Diffusion Tensor Imaging (DTI) technique. Region of interest (ROIs) were drawn on corpus callosum (CC), hippocampus (HIP), sensory-motor cortex (SMC), thalamus (TH), hypothalamus (HTH), cingulum (CG), caudeto-putamen (CUP) and cerebral peduncle (CP). The differences in FA (Fractional Anisotropy) and MD (Mean Diffusivity) values generated from these regions of all the groups were evaluated by ANOVA with multiple comparisons using Bonferroni, Post Hoc test. Maximum changes have been observed in MD values mainly in cranial group showing significantly increased MD in CC and SMC region while both the groups showed changes in TH and CUP region as compared to control. FA showed more prominent changes in whole body radiation group than cranial group by decreasing significantly in CP region while in HTH and CUP region in both the groups. Reduced FA indicates compromised structural integrity due to the loss of glial progenitor cells causing transient demyelination while increased MD has been equated with cellular membrane disruption, cell death and vasogenic edema. Thus, present study reveals late delayed CNS response after cranial and whole body radiation exposure. These findings can help us differentiate and monitor the pathophysiological changes at later stages either due to accidental or intentional exposure to ionizing radiation

  8. Effect of chronic forced swimming stress on whole brain radiation induced cognitive dysfunction and related mechanism

    International Nuclear Information System (INIS)

    Zhang Yuan; Sun Rui; Zhu Yaqun; Zhang Liyuan; Ji Jianfeng; Li Kun; Tian Ye

    2014-01-01

    Objective: To explore whether chronic forced swimming stress could improve whole brain radiation induced cognitive dysfunction and possible mechanism. Methods: Thirty-nine one month old male Sprague-Dawley rats were randomized into sham control group(C), swimming group(C-S), radiation group(R), and radiation plus swimming group(R-S). Radiation groups were given a single dose of 20 Gy on whole-brain. Rats in the swimming groups were trained with swimming of 15 min/d, 5 d/w. Rat behavior was performed 3 months after radiation in an order of free activity in an open field and the Morris water maze test including the place navigation and spatial probe tests. Then, the protein expressions of BDNF, P-ERK, T-ERK, P-CREB and T-CREB in the rat hippocampus tissue were assayed by Western blot. Results: On the day 2, in the place navigation test of Morris water maze, the latency of swimming group was significantly shorter than that of sham group, the latency of sham group was significantly shorter than that of radiation group, and the latency of radiation swimming group was significantly shorter than that of radiation group(P 0.05). Western blot assay showed that the expressions of BDNF and its downstream signals including P-ERK and P-CREB were markedly reduced by radiation (P < 0.05), but this reduction was attenuated by the chronic forced swimming stress. Conclusion: The chronic forced swimming stress could improve whole brain radiation induced cognitive dysfunction by up-regulating the expressions of BDNF and its downstream signal molecules of P-ERK and P-CREB in hippocampus. (authors)

  9. Radiated-induced brain injury: advance of molecular mechanisms and neuroprotection strategies

    International Nuclear Information System (INIS)

    Gao Bo; Wang Xuejian

    2007-01-01

    The underlying mechanisms of radiated-induced brain injury (RBI) remain incompletely clear. Pathophysiological data indicate that the development of RBI involves complex and dynamic interactions between neurons, glia, and vascular endothelial cells within thecentral nervous system (CNS). Radiated-induced injury in the CNS can be modulated by the therapies directed at altering steps in the cascade of events leading to the clinical expression of normal tissue injury. Some neuroprotective strategies are also addressed in the review. (authors)

  10. Brain extraction in partial volumes T2*@7T by using a quasi-anatomic segmentation with bias field correction.

    Science.gov (United States)

    Valente, João; Vieira, Pedro M; Couto, Carlos; Lima, Carlos S

    2018-02-01

    Poor brain extraction in Magnetic Resonance Imaging (MRI) has negative consequences in several types of brain post-extraction such as tissue segmentation and related statistical measures or pattern recognition algorithms. Current state of the art algorithms for brain extraction work on weighted T1 and T2, being not adequate for non-whole brain images such as the case of T2*FLASH@7T partial volumes. This paper proposes two new methods that work directly in T2*FLASH@7T partial volumes. The first is an improvement of the semi-automatic threshold-with-morphology approach adapted to incomplete volumes. The second method uses an improved version of a current implementation of the fuzzy c-means algorithm with bias correction for brain segmentation. Under high inhomogeneity conditions the performance of the first method degrades, requiring user intervention which is unacceptable. The second method performed well for all volumes, being entirely automatic. State of the art algorithms for brain extraction are mainly semi-automatic, requiring a correct initialization by the user and knowledge of the software. These methods can't deal with partial volumes and/or need information from atlas which is not available in T2*FLASH@7T. Also, combined volumes suffer from manipulations such as re-sampling which deteriorates significantly voxel intensity structures making segmentation tasks difficult. The proposed method can overcome all these difficulties, reaching good results for brain extraction using only T2*FLASH@7T volumes. The development of this work will lead to an improvement of automatic brain lesions segmentation in T2*FLASH@7T volumes, becoming more important when lesions such as cortical Multiple-Sclerosis need to be detected. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Prognosis of patients treated with whole brain radiation therapy for metastatic gestational trophoblastic disease

    International Nuclear Information System (INIS)

    Schechter, Naomi R.; Mychalczak, Borys; Jones, Walter; Spriggs, David

    1996-01-01

    Purpose/Objective: To evaluate the effect of multiple treatment and disease related variables on the local control and survival of patients receiving whole brain radiation therapy for metastatic gestational trophoblastic disease. Materials and Methods: Between November 1967 and December 1994, 21 patients were treated at our institution for gestational trophoblastic disease metastatic to the brain. 29% ((6(21))) were diagnosed with their brain metastases before the onset of chemotherapy (early group). 79% ((15(21))) developed their brain metastases during or after the administration of first-line chemotherapy (late group). All patients were treated with whole brain radiation therapy. The total dose ranged from 200 cGy to 3600 cGy (median 2200 cGy). Sixteen patients (76%) received concurrent systemic chemotherapy. None of the patients received intrathecal chemotherapy as a component of their initial treatment. Survival and local control were calculated from the date of diagnosis of brain metastases. Follow-up ranged from 11 months to 170 months with a median of 77 months. Results: The median overall survival was 21 months, with 2- and 5-year actuarial survivals of 46% and 31%, respectively. Neither survival nor local control was significantly affected by age at diagnosis of brain metastases (<35 vs. ≥35 years), time of presentation of brain metastases (early vs. late), or use of concurrent chemotherapy. The total dose of radiation (<2200 cGy vs. ≥2200 cGy) significantly affected initial local control, but not survival. The 5-year actuarial local control of the initial brain metastases with ≥2200 cGy was 91%, as compared to 24% with <2200 cGy (p=0.05). Survival was significantly affected by control of disease at extracranial sites. The 2- and 5-year actuarial survivals of the 9 patients whose disease was controlled at extracranial sites were 100% and 83%, respectively, as compared to 8% and 0% for the 12 whose extracranial disease was not controlled (p=0

  12. Local brain herniation after partial membranectomy for organized chronic subdural hematoma in an adult patient: case report and review of the literature.

    Science.gov (United States)

    Kusano, Yoshikazu; Horiuchi, Tetsuyoshi; Seguchi, Tatsuya; Kakizawa, Yukinari; Tanaka, Yuichiro; Hongo, Kazuhiro

    2010-01-01

    Local brain herniation after removal of chronic subdural haematoma is extremely rare, especially in adult patients. This study reports a case of local brain herniation after partial membranectomy for organized chronic subdural haematoma. A 77-year-old man presented with dysarthria and dysphasia caused by local brain herniation of the right frontal lobe through a defect of the inner membrane. The herniated brain was detected by magnetic resonance (MR) imaging. The patient underwent a craniotomy to release the herniated and strangulated brain, which were consistent with the MR imaging findings. The patient recovered fully within 1 month after surgery. To date, five cases of brain herniation through the internal subdural membrane have been reported as complications of chronic subdural haematomas. All but one case occurred in the paediatric population. Urgent surgery should be performed, even if an adult patient suffers from local brain herniation, for preservation of brain function. This is the sixth reported case of brain herniation through a defect of the inner membrane and the second reported case in the adult population.

  13. Effects of partial volume correction on discrimination between very early Alzheimer's dementia and controls using brain perfusion SPECT

    International Nuclear Information System (INIS)

    Kanetaka, Hidekazu; Matsuda, Hiroshi; Ohnishi, Takashi; Imabayashi, Etsuko; Tanaka, Fumiko; Asada, Takashi; Yamashita, Fumio; Nakano, Seigo; Takasaki, Masaru

    2004-01-01

    We assessed the accuracy of brain perfusion single-photon emission computed tomography (SPECT) in discriminating between patients with probable Alzheimer's disease (AD) at the very early stage and age-matched controls before and after partial volume correction (PVC). Three-dimensional MRI was used for PVC. We randomly divided the subjects into two groups. The first group, comprising 30 patients and 30 healthy volunteers, was used to identify the brain area with the most significant decrease in regional cerebral blood flow (rCBF) in patients compared with normal controls based on the voxel-based analysis of a group comparison. The second group, comprising 31 patients and 31 healthy volunteers, was used to study the improvement in diagnostic accuracy provided by PVC. A Z score map for a SPECT image of a subject was obtained by comparison with mean and standard deviation SPECT images of the healthy volunteers for each voxel after anatomical standardization and voxel normalization to global mean or cerebellar values using the following equation: Z score = ([control mean]-[individual value])/(control SD). Analysis of receiver operating characteristics curves for a Z score discriminating AD and controls in the posterior cingulate gyrus, where a significant decrease in rCBF was identified in the first group, showed that the PVC significantly enhanced the accuracy of the SPECT diagnosis of very early AD from 73.9% to 83.7% with global mean normalization. The PVC mildly enhanced the accuracy from 73.1% to 76.3% with cerebellar normalization. This result suggests that early diagnosis of AD requires PVC in a SPECT study. (orig.)

  14. Delayed radiation injury of brain stem after radiotherapy in nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Yang Yunli; Liu Yingxin; Xie Dong; Su Danke; Chen Mingzhong

    2002-01-01

    Objective: To study the clinical characteristics, MRI findings, diagnosis, treatment and prognostic factors of patients with radiation induced brain stem injury in nasopharyngeal carcinoma. Methods: From January 1991 to January 2001, 24 patients with radiation injury of brain stem were treated, 14 males and 10 females. The latency ranged from 6 to 38 months, with a median of 18 months. The lesions were located in the pons in 10 patients, mesencephalon + pons in 4, pons + medulla oblongata in 5, medulla oblongata in 2 and mesencephalon + pons + medulla oblongata in 3. MRI findings showed that the injury was chiefly presented as hypointensity foci on T 1 WI and hyperintensity foci on T 2 WI. Results: Eighteen patients were treated with dexamethasone in the early phase, with symptoms relieved in 12 patients but unimproved in 6 patients. Eight 44% patients died within the 8-38 months, leaving 16 patients surviving for 0.5 to 6.0 years. Conclusions: Radiation injury of brain stem has a short latency with severe symptoms, signifying poor prognosis. It is suggested that adequate reduction of irradiation volume and dose at the brain stem should be able to lower the incidence of brain stem injury

  15. Ionizing radiation alters beta-endorphin-like immunoreactivity in brain but not blood

    Energy Technology Data Exchange (ETDEWEB)

    Mickley, G.A.; Stevens, K.E.; Moore, G.H.; Deere, W.; White, G.A.; Gibbs, G.L.; Mueller, G.P.

    1983-12-01

    Previous behavioral and pharmacological studies have implicated endorphins in radiation-induced locomotor hyperactivity of the C57BL/6J mouse. However, the endogenous opiate(s) responsible for this behavioral change have not been identified. The present study measured beta-endorphin-like immunoreactivity (beta-END-LI) in brain, blood, and combined brain and pituitary samples from irradiated and sham-irradiated C57BL/6J mice. After radiation exposure, levels of beta-END-LI decreased significantly in the brain. A similar, but not statistically significant, decline was measured in combined brain and pituitary samples. Concentrations of blood beta-END-LI were not changed by irradiation. These radiogenic changes in beta-END-LI are in some ways similar to those observed after other stresses. However, radiation-induced locomotor hyperactivity may be mediated more by alterations of beta-END-LI in the brain than in the periphery. Other endogenous opiate systems may also contribute to this behavioral change in the C57BL/6J mouse.

  16. Ionizing radiation alters beta-endorphin-like immunoreactivity in brain but not blood

    International Nuclear Information System (INIS)

    Mickley, G.A.; Stevens, K.E.; Moore, G.H.; Deere, W.; White, G.A.; Gibbs, G.L.; Mueller, G.P.

    1983-01-01

    Previous behavioral and pharmacological studies have implicated endorphins in radiation-induced locomotor hyperactivity of the C57BL/6J mouse. However, the endogenous opiate(s) responsible for this behavioral change have not been identified. The present study measured beta-endorphin-like immunoreactivity (beta-END-LI) in brain, blood, and combined brain and pituitary samples from irradiated and sham-irradiated C57BL/6J mice. After radiation exposure, levels of beta-END-LI decreased significantly in the brain. A similar, but not statistically significant, decline was measured in combined brain and pituitary samples. Concentrations of blood beta-END-LI were not changed by irradiation. These radiogenic changes in beta-END-LI are in some ways similar to those observed after other stresses. However, radiation-induced locomotor hyperactivity may be mediated more by alterations of beta-END-LI in the brain than in the periphery. Other endogenous opiate systems may also contribute to this behavioral change in the C57BL/6J mouse

  17. Complete adrenocorticotropin deficiency after radiation therapy for brain tumor with a normal growth hormone reserve

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Haruna; Yoshioka, Katsunobu; Yamagami, Keiko [Osaka City General Hospital (Japan)] (and others)

    2002-06-01

    A 34-year-old man with neurofibromatosis type 1, who had received radiation therapy after the excision of a brain tumor 5 years earlier, was admitted to our hospital with vomiting and weight loss. Cortisol and adrenocorticotropin (ACTH) were undetectable before and after administration of 100 {mu}g corticotropin releasing hormone. The level of growth hormone without stimulation was 24.7 ng/ml. We diagnosed him to have complete ACTH deficiency attributable to radiation therapy. This is the first known case of a patient with complete ACTH deficiency after radiation therapy and a growth hormone reserve that remained normal. (author)

  18. Complete adrenocorticotropin deficiency after radiation therapy for brain tumor with a normal growth hormone reserve

    International Nuclear Information System (INIS)

    Sakai, Haruna; Yoshioka, Katsunobu; Yamagami, Keiko

    2002-01-01

    A 34-year-old man with neurofibromatosis type 1, who had received radiation therapy after the excision of a brain tumor 5 years earlier, was admitted to our hospital with vomiting and weight loss. Cortisol and adrenocorticotropin (ACTH) were undetectable before and after administration of 100 μg corticotropin releasing hormone. The level of growth hormone without stimulation was 24.7 ng/ml. We diagnosed him to have complete ACTH deficiency attributable to radiation therapy. This is the first known case of a patient with complete ACTH deficiency after radiation therapy and a growth hormone reserve that remained normal. (author)

  19. Partially acoustic dark matter, interacting dark radiation, and large scale structure

    Energy Technology Data Exchange (ETDEWEB)

    Chacko, Zackaria [Maryland Center for Fundamental Physics, Department of Physics, University of Maryland,Stadium Dr., College Park, MD 20742 (United States); Cui, Yanou [Maryland Center for Fundamental Physics, Department of Physics, University of Maryland,Stadium Dr., College Park, MD 20742 (United States); Department of Physics and Astronomy, University of California-Riverside,University Ave, Riverside, CA 92521 (United States); Perimeter Institute, 31 Caroline Street, North Waterloo, Ontario N2L 2Y5 (Canada); Hong, Sungwoo [Maryland Center for Fundamental Physics, Department of Physics, University of Maryland,Stadium Dr., College Park, MD 20742 (United States); Okui, Takemichi [Department of Physics, Florida State University,College Avenue, Tallahassee, FL 32306 (United States); Tsai, Yuhsinz [Maryland Center for Fundamental Physics, Department of Physics, University of Maryland,Stadium Dr., College Park, MD 20742 (United States)

    2016-12-21

    The standard paradigm of collisionless cold dark matter is in tension with measurements on large scales. In particular, the best fit values of the Hubble rate H{sub 0} and the matter density perturbation σ{sub 8} inferred from the cosmic microwave background seem inconsistent with the results from direct measurements. We show that both problems can be solved in a framework in which dark matter consists of two distinct components, a dominant component and a subdominant component. The primary component is cold and collisionless. The secondary component is also cold, but interacts strongly with dark radiation, which itself forms a tightly coupled fluid. The growth of density perturbations in the subdominant component is inhibited by dark acoustic oscillations due to its coupling to the dark radiation, solving the σ{sub 8} problem, while the presence of tightly coupled dark radiation ameliorates the H{sub 0} problem. The subdominant component of dark matter and dark radiation continue to remain in thermal equilibrium until late times, inhibiting the formation of a dark disk. We present an example of a simple model that naturally realizes this scenario in which both constituents of dark matter are thermal WIMPs. Our scenario can be tested by future stage-IV experiments designed to probe the CMB and large scale structure.

  20. Partially acoustic dark matter, interacting dark radiation, and large scale structure

    International Nuclear Information System (INIS)

    Chacko, Zackaria; Cui, Yanou; Hong, Sungwoo; Okui, Takemichi; Tsai, Yuhsinz

    2016-01-01

    The standard paradigm of collisionless cold dark matter is in tension with measurements on large scales. In particular, the best fit values of the Hubble rate H 0 and the matter density perturbation σ 8 inferred from the cosmic microwave background seem inconsistent with the results from direct measurements. We show that both problems can be solved in a framework in which dark matter consists of two distinct components, a dominant component and a subdominant component. The primary component is cold and collisionless. The secondary component is also cold, but interacts strongly with dark radiation, which itself forms a tightly coupled fluid. The growth of density perturbations in the subdominant component is inhibited by dark acoustic oscillations due to its coupling to the dark radiation, solving the σ 8 problem, while the presence of tightly coupled dark radiation ameliorates the H 0 problem. The subdominant component of dark matter and dark radiation continue to remain in thermal equilibrium until late times, inhibiting the formation of a dark disk. We present an example of a simple model that naturally realizes this scenario in which both constituents of dark matter are thermal WIMPs. Our scenario can be tested by future stage-IV experiments designed to probe the CMB and large scale structure.

  1. Radio frequency radiation effects on protein kinase C activity in rats' brain

    International Nuclear Information System (INIS)

    Paulraj, R.; Behari, J.

    2004-01-01

    The present work describes the effect of amplitude modulated radio frequency (rf) radiation (112 MHz amplitude-modulated at 16 Hz) on calcium-dependent protein kinase C (PKC) activity on developing rat brain. Thirty-five days old Wistar rats were used for this study. The rats were exposed 2 h per day for 35 days at a power density of 1.0 mW/cm 2 (SAR=1.48 W/kg). After exposure, rats were sacrificed and PKC was determined in whole brain, hippocampus and whole brain minus hippocampus separately. A significant decrease in the enzyme level was observed in the exposed group as compared to the sham exposed group. These results indicate that this type of radiation could affect membrane bound enzymes associated with cell signaling, proliferation and differentiation. This may also suggest an affect on the behavior of chronically exposed rats

  2. Primate study suggests pentobarbital may help protect the brain during radiation therapy

    International Nuclear Information System (INIS)

    Skolnick, A.

    1990-01-01

    Radiation therapy, an often indispensable treatment for a wide range of brain tumors, is a double-edged sword, especially when used to treat children. Research reported at the 72nd Annual Meeting of the Endocrine Society, in Atlanta, Ga., now suggests that pentobarbital and perhaps other barbiturates may help protect the brain from radiation-induced damage, especially to the pituitary and hypothalmus, where such damage can lead to serious, life-long problems for children. Jeffrey J. Olson, MD, now assistant professor of neurosurgery at Emory University School of Medicine, Atlanta, reported the results of a study of the radioprotective effects of pentobarbital on the brain of a primate, which he and colleagues at the National Institute of Neurological Disorders and Stroke recently completed

  3. Effects of partial slip boundary condition and radiation on the heat and mass transfer of MHD-nanofluid flow

    Science.gov (United States)

    Abd Elazem, Nader Y.; Ebaid, Abdelhalim

    2017-12-01

    In this paper, the effect of partial slip boundary condition on the heat and mass transfer of the Cu-water and Ag-water nanofluids over a stretching sheet in the presence of magnetic field and radiation. Such partial slip boundary condition has attracted much attention due to its wide applications in industry and chemical engineering. The flow is basically governing by a system of partial differential equations which are reduced to a system of ordinary differential equations. This system has been exactly solved, where exact analytical expression has been obtained for the fluid velocity in terms of exponential function, while the temperature distribution, and the nanoparticles concentration are expressed in terms of the generalized incomplete gamma function. In addition, explicit formulae are also derived from the rates of heat transfer and mass transfer. The effects of the permanent parameters on the skin friction, heat transfer coefficient, rate of mass transfer, velocity, the temperature profile, and concentration profile have been discussed through tables and graphs.

  4. Radiation-induced dementia in patients cured of brain metastases

    International Nuclear Information System (INIS)

    DeAngelis, L.M.; Delattre, J.Y.; Posner, J.B.

    1989-01-01

    When a patient with cancer develops a brain metastasis, death is usually imminent, but aggressive treatment in some patients with limited or no systemic disease yields long-term survival. In such patients, delayed deleterious effects of therapy are particularly tragic. We report 12 patients who developed delayed complications of whole brain radiotherapy (WBRT) given as sole treatment (4 patients) or in combination with surgical resection (8 patients). Within 5 to 36 months (median, 14) all patients developed progressive dementia, ataxia, and urinary incontinence causing severe disability in all and leading to death in 7. No patient had tumor recurrence when neurologic symptoms began. Cortical atrophy and hypodense white matter were identified by CT in all. Contrast-enhancing lesions were seen in 3 patients; 2 of the lesions yielded radionecrosis on biopsy. Autopsies on 2 patients revealed diffuse chronic edema of the hemispheric white matter in the absence of tumor recurrence. Corticosteroids and ventriculoperitoneal shunt offered significant but incomplete improvement in some patients. The total dose of WBRT was only 2,500 to 3,900 cGy, but daily fractions of 300 to 600 cGy were employed. We believe that these fractionation schedules, several of which are used commonly, predispose to delayed neurologic toxicity, and that more protracted schedules should be employed for the safe and efficacious treatment of good-risk patients with brain metastases. The incidence of WBRT-induced dementia was only 1.9 to 5.1% in the 2 populations reviewed here; however, this underestimates the incidence because only severely affected patients could be identified from chart review

  5. Target volumes in radiation therapy of childhood brain tumours

    International Nuclear Information System (INIS)

    Habrand, J.L.; Abdulkarim, B.; Beaudre, A.; El Khouri, M.; Kalifa, C.

    2001-01-01

    Pediatric tumors have enjoyed considerable improvements for the past 30 years. This is mainly due to the extensive use of combined therapeutical modalities in which chemotherapy plays a prominent role. In many children, local treatment including radiotherapy, can nowadays be adapted in terms of target volume and dose to the 'response' to an initial course of chemotherapy almost on a case by case basis. This makes precise recommendation on local therapy highly difficult in this age group. We will concentrate in this paper on brain tumors in which chemotherapy is of limited value and radiotherapy still plays a key-role. (authors)

  6. Delayed brain radiation necrosis: pathological review and new molecular targets for treatment.

    Science.gov (United States)

    Furuse, Motomasa; Nonoguchi, Naosuke; Kawabata, Shinji; Miyatake, Shin-Ichi; Kuroiwa, Toshihiko

    2015-12-01

    Delayed radiation necrosis is a well-known adverse event following radiotherapy for brain diseases and has been studied since the 1930s. The primary pathogenesis is thought to be the direct damage to endothelial and glial cells, particularly oligodendrocytes, which causes vascular hyalinization and demyelination. This primary pathology leads to tissue inflammation and ischemia, inducing various tissue protective responses including angiogenesis. Macrophages and lymphocytes then infiltrate the surrounding areas of necrosis, releasing inflammatory cytokines such as interleukin (IL)-1α, IL-6, and tumor necrosis factor (TNF)-α. Microglia also express these inflammatory cytokines. Reactive astrocytes play an important role in angiogenesis, expressing vascular endothelial growth factor (VEGF). Some chemokine networks, like the CXCL12/CXCR4 axis, are upregulated by tissue inflammation. Hypoxia may mediate the cell-cell interactions among reactive astrocytes, macrophages, and microglial cells around the necrotic core. Recently, bevacizumab, an anti-VEGF antibody, has demonstrated promising results as an alternative treatment for radiation necrosis. The importance of VEGF in the pathophysiology of brain radiation necrosis is being recognized. The discovery of new molecular targets could facilitate novel treatments for radiation necrosis. This literature review will focus on recent work characterizing delayed radiation necrosis in the brain.

  7. Radiation-induced brain damage in children; Histological analysis of sequential tissue changes in 34 autopsy cases

    Energy Technology Data Exchange (ETDEWEB)

    Oi, Shizuo; Kokunai, Takashi; Ijichi, Akihiro; Matsumoto, Satoshi [Kobe Univ. (Japan). School of Medicine; Raimondi, A J

    1990-01-01

    The nature and sequence of the radiation-induced changes in the brain were studied postmortem in 34 children with glioma, 22 of whom underwent central nervous system radiation therapy. Twenty received whole-brain or whole-neuroaxis radiation at a total mean dosage of 4063 cGy. Brain tissue alternations were analyzed histologically by means of various staining methods, including immunohistochemical techniques. The histological features of irradiated brains were compared with those of non-irradiated brains. Microscopic findings included demyelination (seven cases), focal necrosis (six cases), cortical atrophy (four cases), endothelial proliferation (four cases), and telangiectatic vascular proliferation with vascular thickening and oozing of a thick fluid (one case). Such findings were rare in non-irradiated patients. Demyelination was observed earliest in a patient who died 5 months after radiation therapy and was more common after 9 months. Focal necrosis was first observed 9 months post-irradiation but was more advanced and extensive after 1 year. Calcified foci were found only after 60 months. Various vascular changes such as vascular thickening and thrombosis suggested ischemic insult to the brain as a late effect of radiation injury. The results of this study suggest that the immature brain may be more sensitive to radiation than is the adult brain, and that the manifestations of radiation-induced injury depend on the time elapsed after irradiation. (author).

  8. New three-dimensional moving field radiation therapy for brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Mitsuyama, Fuyuki; Kanno, Tetsuo; Nagata, Yutaka; Koga, Sukehiko [Fujita-Gakuen Health Univ., Toyoake, Aichi (Japan); Jain, V K

    1992-06-01

    A new modified rotation radiation method called 'three-dimensional moving field radiation therapy' is described. The new method uses rotation in many planes while maintaining the same isocenter to achieve a good spatial dose distribution. This delivers a high dose to tumors and spares the surrounding normal structures. This easy method can be carried out using the equipment for conventional rotation radiation therapy. The new method was superior to the one plane rotation radiation therapy using a physical phantom with film, a chemical phantom using the iodine-starch reaction, and a new biological model using tumor cells. Treatment of six brain tumors irradiated with total air doses of 50-60 Gy caused no hair loss or radiation necrosis. (author).

  9. External Validity of a Risk Stratification Score Predicting Early Distant Brain Failure and Salvage Whole Brain Radiation Therapy After Stereotactic Radiosurgery for Brain Metastases.

    Science.gov (United States)

    Press, Robert H; Boselli, Danielle M; Symanowski, James T; Lankford, Scott P; McCammon, Robert J; Moeller, Benjamin J; Heinzerling, John H; Fasola, Carolina E; Burri, Stuart H; Patel, Kirtesh R; Asher, Anthony L; Sumrall, Ashley L; Curran, Walter J; Shu, Hui-Kuo G; Crocker, Ian R; Prabhu, Roshan S

    2017-07-01

    A scoring system using pretreatment factors was recently published for predicting the risk of early (≤6 months) distant brain failure (DBF) and salvage whole brain radiation therapy (WBRT) after stereotactic radiosurgery (SRS) alone. Four risk factors were identified: (1) lack of prior WBRT; (2) melanoma or breast histologic features; (3) multiple brain metastases; and (4) total volume of brain metastases external patient population. We reviewed the records of 247 patients with 388 brain metastases treated with SRS between 2010 at 2013 at Levine Cancer Institute. The Press (Emory) risk score was calculated and applied to the validation cohort population, and subsequent risk groups were analyzed using cumulative incidence. The low-risk (LR) group had a significantly lower risk of early DBF than did the high-risk (HR) group (22.6% vs 44%, P=.004), but there was no difference between the HR and intermediate-risk (IR) groups (41.2% vs 44%, P=.79). Total lesion volume externally valid, but the model was able to stratify between 2 levels (LR and not-LR [combined IR and HR]) for early (≤6 months) DBF. These results reinforce the importance of validating predictive models in independent cohorts. Further refinement of this scoring system with molecular information and in additional contemporary patient populations is warranted. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. A randomised trial to compare cognitive outcome after gamma knife radiosurgery versus whole brain radiation therapy in patients with multiple brain metastases : Research protocol CAR-study B

    NARCIS (Netherlands)

    Schimmel, W.C.M.; Verhaak, E.; Hanssens, Patrick E. J.; Gehring, K.; Sitskoorn, M.M.

    2018-01-01

    Background Gamma Knife radiosurgery (GKRS) is increasingly applied in patients with multiple brain metastases and is expected to have less adverse effects in cognitive functioning than whole brain radiation therapy (WBRT). Effective treatment with the least negative cognitive side effects is

  11. Radiation-related damage to the developing human brain

    International Nuclear Information System (INIS)

    Schull, W.J.; Yoshimaru, Hiroshi; Kyorin Univ., Tokyo

    1989-01-01

    The authors summarize the significant dose-related effects on brain development which have emerged largely within the last six years of study of prenatally exposed A-bomb survivors. The results are described primarily in terms of the DS86 estimates and differences between these and the older T65DR dose estimates are discussed. The severe mental retardation sample was based on 1598 individuals taken from the PE-86 sample, and the intelligence test scores considered from the same sample involved 1673 children. The authors also discuss some of the recent neurobiological developments that appear relevant to an understanding of the biological bases of dose-related events observed, and suggest future research that may contribute either to further delineation of exposure consequences or to the explanation of the cellular and molecular origins of observed effects. (UK)

  12. Whole-brain hippocampal sparing radiation therapy: Volume-modulated arc therapy vs intensity-modulated radiation therapy case study

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Katrina, E-mail: Trinabena23@gmail.com; Lenards, Nishele; Holson, Janice

    2016-04-01

    The hippocampus is responsible for memory and cognitive function. An ongoing phase II clinical trial suggests that sparing dose to the hippocampus during whole-brain radiation therapy can help preserve a patient's neurocognitive function. Progressive research and advancements in treatment techniques have made treatment planning more sophisticated but beneficial for patients undergoing treatment. The aim of this study is to evaluate and compare hippocampal sparing whole-brain (HS-WB) radiation therapy treatment planning techniques using volume-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT). We randomly selected 3 patients to compare different treatment techniques that could be used for reducing dose to the hippocampal region. We created 2 treatment plans, a VMAT and an IMRT, from each patient's data set and planned on the Eclipse 11.0 treatment planning system (TPS). A total of 6 plans (3 IMRT and 3 VMAT) were created and evaluated for this case study. The physician contoured the hippocampus as per the Radiation Therapy Oncology Group (RTOG) 0933 protocol atlas. The organs at risk (OR) were contoured and evaluated for the plan comparison, which included the spinal cord, optic chiasm, the right and left eyes, lenses, and optic nerves. Both treatment plans produced adequate coverage on the planning target volume (PTV) while significantly reducing dose to the hippocampal region. The VMAT treatment plans produced a more homogenous dose distribution throughout the PTV while decreasing the maximum point dose to the target. However, both treatment techniques demonstrated hippocampal sparing when irradiating the whole brain.

  13. Whole-brain hippocampal sparing radiation therapy: Volume-modulated arc therapy vs intensity-modulated radiation therapy case study.

    Science.gov (United States)

    Lee, Katrina; Lenards, Nishele; Holson, Janice

    2016-01-01

    The hippocampus is responsible for memory and cognitive function. An ongoing phase II clinical trial suggests that sparing dose to the hippocampus during whole-brain radiation therapy can help preserve a patient׳s neurocognitive function. Progressive research and advancements in treatment techniques have made treatment planning more sophisticated but beneficial for patients undergoing treatment. The aim of this study is to evaluate and compare hippocampal sparing whole-brain (HS-WB) radiation therapy treatment planning techniques using volume-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT). We randomly selected 3 patients to compare different treatment techniques that could be used for reducing dose to the hippocampal region. We created 2 treatment plans, a VMAT and an IMRT, from each patient׳s data set and planned on the Eclipse 11.0 treatment planning system (TPS). A total of 6 plans (3 IMRT and 3 VMAT) were created and evaluated for this case study. The physician contoured the hippocampus as per the Radiation Therapy Oncology Group (RTOG) 0933 protocol atlas. The organs at risk (OR) were contoured and evaluated for the plan comparison, which included the spinal cord, optic chiasm, the right and left eyes, lenses, and optic nerves. Both treatment plans produced adequate coverage on the planning target volume (PTV) while significantly reducing dose to the hippocampal region. The VMAT treatment plans produced a more homogenous dose distribution throughout the PTV while decreasing the maximum point dose to the target. However, both treatment techniques demonstrated hippocampal sparing when irradiating the whole brain. Copyright © 2016 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

  14. Cost-effective immobilization for whole brain radiation therapy.

    Science.gov (United States)

    Rubinstein, Ashley E; Ingram, W Scott; Anderson, Brian M; Gay, Skylar S; Fave, Xenia J; Ger, Rachel B; McCarroll, Rachel E; Owens, Constance A; Netherton, Tucker J; Kisling, Kelly D; Court, Laurence E; Yang, Jinzhong; Li, Yuting; Lee, Joonsang; Mackin, Dennis S; Cardenas, Carlos E

    2017-07-01

    To investigate the inter- and intra-fraction motion associated with the use of a low-cost tape immobilization technique as an alternative to thermoplastic immobilization masks for whole-brain treatments. The results of this study may be of interest to clinical staff with severely limited resources (e.g., in low-income countries) and also when treating patients who cannot tolerate standard immobilization masks. Setup reproducibility of eight healthy volunteers was assessed for two different immobilization techniques. (a) One strip of tape was placed across the volunteer's forehead and attached to the sides of the treatment table. (b) A second strip was added to the first, under the chin, and secured to the table above the volunteer's head. After initial positioning, anterior and lateral photographs were acquired. Volunteers were positioned five times with each technique to allow calculation of inter-fraction reproducibility measurements. To estimate intra-fraction reproducibility, 5-minute anterior and lateral videos were taken for each technique per volunteer. An in-house software was used to analyze the photos and videos to assess setup reproducibility. The maximum intra-fraction displacement for all volunteers was 2.8 mm. Intra-fraction motion increased with time on table. The maximum inter-fraction range of positions for all volunteers was 5.4 mm. The magnitude of inter-fraction and intra-fraction motion found using the "1-strip" and "2-strip" tape immobilization techniques was comparable to motion restrictions provided by a thermoplastic mask for whole-brain radiotherapy. The results suggest that tape-based immobilization techniques represent an economical and useful alternative to the thermoplastic mask. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  15. On the Green's function of the partially diffusion-controlled reversible ABCD reaction for radiation chemistry codes

    International Nuclear Information System (INIS)

    Plante, Ianik; Devroye, Luc

    2015-01-01

    Several computer codes simulating chemical reactions in particles systems are based on the Green's functions of the diffusion equation (GFDE). Indeed, many types of chemical systems have been simulated using the exact GFDE, which has also become the gold standard for validating other theoretical models. In this work, a simulation algorithm is presented to sample the interparticle distance for partially diffusion-controlled reversible ABCD reaction. This algorithm is considered exact for 2-particles systems, is faster than conventional look-up tables and uses only a few kilobytes of memory. The simulation results obtained with this method are compared with those obtained with the independent reaction times (IRT) method. This work is part of our effort in developing models to understand the role of chemical reactions in the radiation effects on cells and tissues and may eventually be included in event-based models of space radiation risks. However, as many reactions are of this type in biological systems, this algorithm might play a pivotal role in future simulation programs not only in radiation chemistry, but also in the simulation of biochemical networks in time and space as well

  16. On the Green's function of the partially diffusion-controlled reversible ABCD reaction for radiation chemistry codes

    Energy Technology Data Exchange (ETDEWEB)

    Plante, Ianik, E-mail: ianik.plante-1@nasa.gov [Wyle Science, Technology & Engineering, 1290 Hercules, Houston, TX 77058 (United States); Devroye, Luc, E-mail: lucdevroye@gmail.com [School of Computer Science, McGill University, 3480 University Street, Montreal H3A 0E9 (Canada)

    2015-09-15

    Several computer codes simulating chemical reactions in particles systems are based on the Green's functions of the diffusion equation (GFDE). Indeed, many types of chemical systems have been simulated using the exact GFDE, which has also become the gold standard for validating other theoretical models. In this work, a simulation algorithm is presented to sample the interparticle distance for partially diffusion-controlled reversible ABCD reaction. This algorithm is considered exact for 2-particles systems, is faster than conventional look-up tables and uses only a few kilobytes of memory. The simulation results obtained with this method are compared with those obtained with the independent reaction times (IRT) method. This work is part of our effort in developing models to understand the role of chemical reactions in the radiation effects on cells and tissues and may eventually be included in event-based models of space radiation risks. However, as many reactions are of this type in biological systems, this algorithm might play a pivotal role in future simulation programs not only in radiation chemistry, but also in the simulation of biochemical networks in time and space as well.

  17. Radiation-Induced Alterations in Mouse Brain Development Characterized by Magnetic Resonance Imaging

    International Nuclear Information System (INIS)

    Gazdzinski, Lisa M.; Cormier, Kyle; Lu, Fred G.; Lerch, Jason P.; Wong, C. Shun; Nieman, Brian J.

    2012-01-01

    Purpose: The purpose of this study was to identify regions of altered development in the mouse brain after cranial irradiation using longitudinal magnetic resonance imaging (MRI). Methods and Materials: Female C57Bl/6 mice received a whole-brain radiation dose of 7 Gy at an infant-equivalent age of 2.5 weeks. MRI was performed before irradiation and at 3 time points following irradiation. Deformation-based morphometry was used to quantify volume and growth rate changes following irradiation. Results: Widespread developmental deficits were observed in both white and gray matter regions following irradiation. Most of the affected brain regions suffered an initial volume deficit followed by growth at a normal rate, remaining smaller in irradiated brains compared with controls at all time points examined. The one exception was the olfactory bulb, which in addition to an early volume deficit, grew at a slower rate thereafter, resulting in a progressive volume deficit relative to controls. Immunohistochemical assessment revealed demyelination in white matter and loss of neural progenitor cells in the subgranular zone of the dentate gyrus and subventricular zone. Conclusions: MRI can detect regional differences in neuroanatomy and brain growth after whole-brain irradiation in the developing mouse. Developmental deficits in neuroanatomy persist, or even progress, and may serve as useful markers of late effects in mouse models. The high-throughput evaluation of brain development enabled by these methods may allow testing of strategies to mitigate late effects after pediatric cranial irradiation.

  18. Radiation-Induced Alterations in Mouse Brain Development Characterized by Magnetic Resonance Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gazdzinski, Lisa M.; Cormier, Kyle [Mouse Imaging Centre, Hospital for Sick Children, Toronto (Canada); Lu, Fred G. [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto (Canada); Lerch, Jason P. [Mouse Imaging Centre, Hospital for Sick Children, Toronto (Canada); Department of Medical Biophysics, University of Toronto, Toronto (Canada); Wong, C. Shun [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Toronto (Canada); Department of Medical Biophysics, University of Toronto, Toronto (Canada); Department of Radiation Oncology, University of Toronto, Toronto (Canada); Nieman, Brian J., E-mail: bjnieman@phenogenomics.ca [Mouse Imaging Centre, Hospital for Sick Children, Toronto (Canada); Department of Medical Biophysics, University of Toronto, Toronto (Canada)

    2012-12-01

    Purpose: The purpose of this study was to identify regions of altered development in the mouse brain after cranial irradiation using longitudinal magnetic resonance imaging (MRI). Methods and Materials: Female C57Bl/6 mice received a whole-brain radiation dose of 7 Gy at an infant-equivalent age of 2.5 weeks. MRI was performed before irradiation and at 3 time points following irradiation. Deformation-based morphometry was used to quantify volume and growth rate changes following irradiation. Results: Widespread developmental deficits were observed in both white and gray matter regions following irradiation. Most of the affected brain regions suffered an initial volume deficit followed by growth at a normal rate, remaining smaller in irradiated brains compared with controls at all time points examined. The one exception was the olfactory bulb, which in addition to an early volume deficit, grew at a slower rate thereafter, resulting in a progressive volume deficit relative to controls. Immunohistochemical assessment revealed demyelination in white matter and loss of neural progenitor cells in the subgranular zone of the dentate gyrus and subventricular zone. Conclusions: MRI can detect regional differences in neuroanatomy and brain growth after whole-brain irradiation in the developing mouse. Developmental deficits in neuroanatomy persist, or even progress, and may serve as useful markers of late effects in mouse models. The high-throughput evaluation of brain development enabled by these methods may allow testing of strategies to mitigate late effects after pediatric cranial irradiation.

  19. [Comparison of set-up control for head and neck patients between radiation oncologist and therapists with the aim of partial delegation].

    Science.gov (United States)

    Garcia-Ramirez, M; Maugey, S; Burgaud, L; Carpentey, F; Parezys, E; Carricaburu, M

    2014-11-01

    The aim of this prospective study was to evaluate daily set-up by a radiation oncologist and by radiation therapists using on-board imaging of patients with head and neck cancer in order to calculate margin to PTV (planning target volume) and intent partial delegation of positioning images control. The files of 11 patients with head and neck cancer treated on a Synergy™ (Elekta™) accelerator with on-board imaging system were evaluated. Daily kV-kV images were double-blind reviewed by radiation therapists (7 participants) and by one radiation oncologist. The radiation oncologist's measures were used for margin calculation from CTV to PTV. The difference of measures and the concordance of decisions between radiation therapists and the radiation oncologist were calculated. The 325 measures made by the radiation oncologist resulted in a margin of 5mm to be applied to the CTV in each direction. Nine hundred seventy-seven measures were made by the radiation oncologist and radiation therapists with a difference of 3mm or less in 98.46%. The concordance of decision for a 4mm difference or less to the isocenter was 96.7%. This study confirms the 5mm PTV margin mostly used in ORL. The small gap between the radiation oncologist's and therapists' measures allows a partial delegation of positioning images control. Copyright © 2014 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  20. Current Evidence for Developmental, Structural, and Functional Brain Defects following Prenatal Radiation Exposure

    Directory of Open Access Journals (Sweden)

    Tine Verreet

    2016-01-01

    Full Text Available Ionizing radiation is omnipresent. We are continuously exposed to natural (e.g., radon and cosmic and man-made radiation sources, including those from industry but especially from the medical sector. The increasing use of medical radiation modalities, in particular those employing low-dose radiation such as CT scans, raises concerns regarding the effects of cumulative exposure doses and the inappropriate utilization of these imaging techniques. One of the major goals in the radioprotection field is to better understand the potential health risk posed to the unborn child after radiation exposure to the pregnant mother, of which the first convincing evidence came from epidemiological studies on in utero exposed atomic bomb survivors. In the following years, animal models have proven to be an essential tool to further characterize brain developmental defects and consequent functional deficits. However, the identification of a possible dose threshold is far from complete and a sound link between early defects and persistent anomalies has not yet been established. This review provides an overview of the current knowledge on brain developmental and persistent defects resulting from in utero radiation exposure and addresses the many questions that still remain to be answered.

  1. External Beam Radiotherapy of Recurrent Glioma: Radiation Tolerance of the Human Brain

    Energy Technology Data Exchange (ETDEWEB)

    Sminia, Peter, E-mail: p.sminia@vumc.nl [Department of Radiation Oncology, Radiobiology Section, VU University Medical Center, De Boelelaan 1117, P.O. Box 7057, Amsterdam (Netherlands); Mayer, Ramona [EBG MedAustron GmbH., Viktor Kaplan-Strasse 2, A-2700, Wiener Neustadt (Austria)

    2012-04-05

    Malignant gliomas relapse in close proximity to the resection site, which is the postoperatively irradiated volume. Studies on re-irradiation of glioma were examined regarding radiation-induced late adverse effects (i.e., brain tissue necrosis), to obtain information on the tolerance dose and treatment volume of normal human brain tissue. The studies were analyzed using the linear-quadratic model to express the re-irradiation tolerance in cumulative equivalent total doses when applied in 2 Gy fractions (EQD2{sub cumulative}). Analysis shows that the EQD2{sub cumulative} increases from conventional re-irradiation series to fractionated stereotactic radiotherapy (FSRT) to LINAC-based stereotactic radiosurgery (SRS). The mean time interval between primary radiotherapy and the re-irradiation course was shortened from 30 months for conventional re-irradiation to 17 and 10 months for FSRT and SRS, respectively. Following conventional re-irradiation, radiation-induced normal brain tissue necrosis occurred beyond an EQD2{sub cumulative} around 100 Gy. With increasing conformality of therapy, the smaller the treatment volume is, the higher the radiation dose that can be tolerated. Despite the dose escalation, no increase in late normal tissue toxicity was reported. On basis of our analysis, the use of particle therapy in the treatment of recurrent gliomas, because of the optimized physical dose distribution in the tumour and surrounding healthy brain tissue, should be considered for future clinical trials.

  2. Salvia officinalis l. (sage) Ameliorates Radiation-Induced Oxidative Brain Damage In Rats

    International Nuclear Information System (INIS)

    Osman, N. N.; Abd El Azime, A.Sh.

    2013-01-01

    The present study was designed to investigate the oxidative stress and the role of antioxidant system in the management of gamma irradiation induced whole brain damage in rats . Also, to elucidate the potential role of Salvia officinalis (sage) in alleviating such negative effects. Rats were subjected to gamma radiation (6 Gy). Sage extract was daily given to rats during 14 days before starting irradiation and continued after radiation exposure for another 14 days. The results revealed that the levels of thiobarbituric acid reactive substances (TBARS), protein carbonyl content (PCC) and nitric oxide (NO) content were significantly increased, while the activities of superoxide dismutase (SOD) and catalase (CAT) as well as the reduced glutathione (GSH) content were significantly decreased in the brain homogenate of irradiated rats. Additionally, brain acetylcholinesterase (AChE) as well as alkaline phosphatase (ALP), acid phosphatase (ACP) and lactate dehydrogenase (LDH) activities were significantly increased. On the other hand, the results showed that, administration of sage extract to rats was able to ameliorate the mentioned parameters and the values returned close to the normal ones. It could be concluded that sage extract, by its antioxidant constituents, could modulate radiation induced oxidative stress and enzyme activities in the brain.

  3. External Beam Radiotherapy of Recurrent Glioma: Radiation Tolerance of the Human Brain

    Directory of Open Access Journals (Sweden)

    Peter Sminia

    2012-04-01

    Full Text Available Malignant gliomas relapse in close proximity to the resection site, which is the postoperatively irradiated volume. Studies on re-irradiation of glioma were examined regarding radiation-induced late adverse effects (i.e., brain tissue necrosis, to obtain information on the tolerance dose and treatment volume of normal human brain tissue. The studies were analyzed using the linear-quadratic model to express the re-irradiation tolerance in cumulative equivalent total doses when applied in 2 Gy fractions (EQD2cumulative. Analysis shows that the EQD2cumulative increases from conventional re-irradiation series to fractionated stereotactic radiotherapy (FSRT to LINAC-based stereotactic radiosurgery (SRS. The mean time interval between primary radiotherapy and the re-irradiation course was shortened from 30 months for conventional re-irradiation to 17 and 10 months for FSRT and SRS, respectively. Following conventional re-irradiation, radiation-induced normal brain tissue necrosis occurred beyond an EQD2cumulative around 100 Gy. With increasing conformality of therapy, the smaller the treatment volume is, the higher the radiation dose that can be tolerated. Despite the dose escalation, no increase in late normal tissue toxicity was reported. On basis of our analysis, the use of particle therapy in the treatment of recurrent gliomas, because of the optimized physical dose distribution in the tumour and surrounding healthy brain tissue, should be considered for future clinical trials.

  4. Evaluation of the evoked brain potentials of patients with asthenia and anxiety symptoms and the partial loss of sight

    Directory of Open Access Journals (Sweden)

    Tsira Abdryakhimova

    2017-03-01

    Full Text Available Background. Loss of sight, even partial, especially in adulthood, is accompanied by emotional, motivational and social consequences that directly affect the psychophysiological state of the individual himself, his communication in society and, often, the social status of the subject.  Methods. From the group of patients-volunteers (n=15 with a partial loss of sight of traumatic genesis two groups were formed for carrying out neurophysiological studies: with predominant asthenia and predominant anxiety. The controle group (CG constisted from patients of the same age (n=20 without psychiatric comorbidity. A study of acoustic event-related potentials of the brain (ERP was carried out in the oddball paradigm with the recording of the time and correctness of a simple sensorimotor reaction. Results. Comparative analysis of the asthenia group with the comparison group revealed a sufficient number of indicators of the ERP, which have significant statistical differences. The correctness of the sensorimotor reaction in this group was 98.3 ± 2.44%, whereas in the CG - 92.5 ± 5.74% (U [15; 20] = 62.5, p <0.01. The values of the amplitude of the early positivity of P1 in the asthenia group were 4.25 ± 3.312 μV, and in the CG -4.15 ± 7.933 μV (U [15, 20] = 50, p <0.001. The early negativity in that group was -2.78 ± 2.377 μV, and in the CG it was 10.55 ± 7.466 μV (U [15; 20] = 75; p <0.05.  Conclusion. In the asthenia group this is the correctness of the sensorimotor reaction and the amplitude of the components: P1, N1, P2, N2. In the anxiety group, such indicators were: latency period P1, intervals P1N1 and N2P3, amplitude swing P1N1. A specific marker of the asthenia group, distinguishing it from the CG, was the more positive values of the amplitude of the components P1, N1, P2, N2. Taking into account the low-frequency nature of the modulation of the amplitudes of these components (circa 2 Hz, it can be assumed that nonspecific brainstem

  5. Accelerated Partial Breast Irradiation Consensus Statement From the American Society for Radiation Oncology (ASTRO)

    International Nuclear Information System (INIS)

    Smith, Benjamin D.; Arthur, Douglas W.; Buchholz, Thomas A.; Haffty, Bruce G.; Hahn, Carol A.; Hardenbergh, Patricia H.; Julian, Thomas B.; Marks, Lawrence B.; Todor, Dorin A. Ph.D.; Vicini, Frank A.; Whelan, Timothy J.; White, Julia; Wo, Jennifer Y.; Harris, Jay R.

    2009-01-01

    Purpose: To present guidance for patients and physicians regarding the use of accelerated partial-breast irradiation (APBI), based on current published evidence complemented by expert opinion. Methods and Materials: A systematic search of the National Library of Medicine's PubMed database yielded 645 candidate original research articles potentially applicable to APBI. Of these, 4 randomized trials and 38 prospective single-arm studies were identified. A Task Force composed of all authors synthesized the published evidence and, through a series of meetings, reached consensus regarding the recommendations contained herein. Results: The Task Force proposed three patient groups: (1) a 'suitable' group, for whom APBI outside of a clinical trial is acceptable, (2) a 'cautionary' group, for whom caution and concern should be applied when considering APBI outside of a clinical trial, and (3) an 'unsuitable' group, for whom APBI outside of a clinical trial is not generally considered warranted. Patients who choose treatment with APBI should be informed that whole-breast irradiation (WBI) is an established treatment with a much longer track record that has documented long-term effectiveness and safety. Conclusion: Accelerated partial-breast irradiation is a new technology that may ultimately demonstrate long-term effectiveness and safety comparable to that of WBI for selected patients with early breast cancer. This consensus statement is intended to provide guidance regarding the use of APBI outside of a clinical trial and to serve as a framework to promote additional clinical investigations into the optimal role of APBI in the treatment of breast cancer.

  6. Radiating nonuniform transmission-line systems and the partial element equivalent circuit method

    CERN Document Server

    Nitsch, Juergen; Wollenberg, Gunter

    2009-01-01

    High frequencies of densely packed modern electronic equipment turn even the smallest piece of wire into a transmission line with signal retardation, dispersion, attenuation, and distortion. In electromagnetic environments with high-power microwave or ultra-wideband sources, transmission lines pick up noise currents generated by external electromagnetic fields. These are superimposed on essential signals, the lines acting not only as receiving antennas but radiating parts of the signal energy into the environment. This book is outstanding in its originality. While many textbooks rephrase

  7. Locomotion, physical development, and brain myelination in rats treated with ionizing radiation in utero

    International Nuclear Information System (INIS)

    Zaman, M.S.

    1989-01-01

    Effects of ionizing radiation on the emergence of locomotion skill and some physical development parameters were studied in laboratory rats (Fisher F-344 inbred strain). Rats were treated with 3 different doses of radiation (150 R, 15 R, and 6.8 R) delivered on the 20th day of the prenatal life. Results indicated that relatively moderate (15 R) to high (150 R) doses of radiation have effects on certain locomotion and physical development parameters. Exposure to 150 R affected pivoting, cliff-avoidance, upper jaw tooth eruption, body weight, and organs, such as brain, cerebral cortex, ovary, kidney, heart and spleen weights. Other parameters, such as negative geotaxis, eye opening, and lower jaw tooth eruption appeared to be affected in the 150 R treated animals. Exposure to 15 R affected pivoting and cliff-avoidance parameters. The cerebral cortex weight of the 15 R treated animals was found to be reduced at the age of day 30. Exposure to 6.8 R had no adverse effects on these parameters. Prenatal exposure to 150 R of radiation reduced the cerebral cortex weight by 22.07% at 30 days of age, and 20.15% at 52 days of age which caused a reduction in cerebral cortex myelin content by 20.16, and 22.89% at the ages of day 30 and day 52 respectively. Exposure to 150 R did not affect the myelin content of the cerebellum or the brain stem; or the myelin concentration (mg myelin/g brain tissue weight) of the cerebral cortex, cerebellum, and the brain stem. Exposure to 15 R, and 6.8 R did not affect either the myelin content or the myelin concentration of these brain areas

  8. Aging-Dependent Changes in the Radiation Response of the Adult Rat Brain

    International Nuclear Information System (INIS)

    Schindler, Matthew K.; Forbes, M. Elizabeth; Robbins, Mike E.; Riddle, David R.

    2008-01-01

    Purpose: To assess the impact of aging on the radiation response in the adult rat brain. Methods and Materials: Male rats 8, 18, or 28 months of age received a single 10-Gy dose of whole-brain irradiation (WBI). The hippocampal dentate gyrus was analyzed 1 and 10 weeks later for sensitive neurobiologic markers associated with radiation-induced damage: changes in density of proliferating cells, immature neurons, total microglia, and activated microglia. Results: A significant decrease in basal levels of proliferating cells and immature neurons and increased microglial activation occurred with normal aging. The WBI induced a transient increase in proliferation that was greater in older animals. This proliferation response did not increase the number of immature neurons, which decreased after WBI in young rats, but not in old rats. Total microglial numbers decreased after WBI at all ages, but microglial activation increased markedly, particularly in older animals. Conclusions: Age is an important factor to consider when investigating the radiation response of the brain. In contrast to young adults, older rats show no sustained decrease in number of immature neurons after WBI, but have a greater inflammatory response. The latter may have an enhanced role in the development of radiation-induced cognitive dysfunction in older individuals

  9. Long-term correlation of the electrocorticogram as a bioindicator of brain exposure to ionizing radiation

    Directory of Open Access Journals (Sweden)

    L.A.A. Aguiar

    2015-01-01

    Full Text Available Understanding the effects of radiation and its possible influence on the nervous system are of great clinical interest. However, there have been few electrophysiological studies on brain activity after exposure to ionizing radiation (IR. A new methodological approach regarding the assessment of the possible effects of IR on brain activity is the use of linear and nonlinear mathematical methods in the analysis of complex time series, such as brain oscillations measured using the electrocorticogram (ECoG. The objective of this study was to use linear and nonlinear mathematical methods as biomarkers of gamma radiation regarding cortical electrical activity. Adult Wistar rats were divided into 3 groups: 1 control and 2 irradiated groups, evaluated at 24 h (IR24 and 90 days (IR90 after exposure to 18 Gy of gamma radiation from a cobalt-60 radiotherapy source. The ECoG was analyzed using power spectrum methods for the calculation of the power of delta, theta, alpha and beta rhythms and by means of the α-exponent of the detrended fluctuation analysis (DFA. Using both mathematical methods it was possible to identify changes in the ECoG, and to identify significant changes in the pattern of the recording at 24 h after irradiation. Some of these changes were persistent at 90 days after exposure to IR. In particular, the theta wave using the two methods showed higher sensitivity than other waves, suggesting that it is a possible biomarker of exposure to IR.

  10. Diffuse brain calcification after radiation therapy in infantile cerebral malignant glioma

    International Nuclear Information System (INIS)

    Hondo, Hiroaki; Tanaka, Ryuichi; Yamada, Nobuhisa; Takeda, Norio

    1987-01-01

    We reported a case of infantile cerebral malignant glioma, which showed extensive intracranial calcification following radiation therapy, and reviewed the literature. A 4-month-old female infant was admitted to our hospital because of vomiting, enlargement of the head and convulsive seizures. Computerized tomography (CT) scans demonstrated a heterogeneously contrast-enhanced mass in the right temporo-parieto-occipital region and marked obstructive hydrocephalus. Subsequent to ventriculo-peritoneal shunt, biopsy was performed. The surgical specimen revealed anaplastic glioma. She then underwent whole brain irradiation with 1800 rads before subtotal removal and 3000 rads postoperatively. Calcification was first identified in the right frontal region and left basal ganglia 2.5 months after radiation therapy. At the age of 14 months, CT scans demonstrated extensive intracranial calcification in the cerebral hemispheres, basal ganglias, thalami, pons and cerebellum. A biopsy specimen of the frontal lobe revealed calcospherites of various sizes within and beside the walls of small vessels, but no tumor cells were observed. Cranial radiation therapy is a standard modality for treatment of children with neoplasm in the central nervous system. Since, however this therapy possibly causes long-term complications on the developing brain, it is important to plan radiation therapy for the brain tumor carefully. (author)

  11. Radiation dose-dependent change in brain 1H-MRS

    International Nuclear Information System (INIS)

    Matsushima, Shigeru; Muroka, Mamoru; Uchiyama, Yukio; Morita, Kozo; Nomoto, Yoshihito; Kinosada, Yasutomi.

    1994-01-01

    We have investigated the usefulness of 1 H-magnetic resonance spectroscopy ( 1 H-MRS) for the assessment of acute radiation damage of the human brain. Nineteen patients were treated with the whole brain irradiation. Biochemical changes in white matter were measured by in vivo 1 H-MRS. The measurement was performed 1 or 2 times in each case at radiation doses ranging from 0 to 44.4 Gy with conventional fractionation (2 Gy per fraction, once a day) or accelerated hyperfractionation (1.5 Gy per fraction, twice a day). For the measurement of 1 H-MRS, 1.5T whole body MR system was used and stimulated echo acquisition mode (STEAM) with chemical shift selective (CHESS) pulse was applied. Volume of the interest (VOI) was 2.5 x 2.5 x 2.5 cm 3 , and the repetition time and echo time were 2000 ms and 272 ms, respectively. The acute radiation damage of the brain was evaluated by the change of peak area ratio (PAR) of choline, creatine and N-acetylaspartate (NAA). 1 H-MR spectra obtained before irradiation were different from those observed during irradiation. There were statistically significant (p 1 H-MRS can be useful for assessment of acute radiation damage. (author)

  12. Long-term correlation of the electrocorticogram as a bioindicator of brain exposure to ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, L.A.A.; Nogueira, R.A. [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil). Departamento de Morfologia e Fisiologia Animal. Lab. de Biofisica Teorico-Experimental e Computacional; Silva, I.M.S.; Fernandes, T.S., E-mail: ran.pe@terra.com.br [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil). Departamento de Biofisica e Radiobiologia

    2015-10-15

    Understanding the effects of radiation and its possible influence on the nervous system are of great clinical interest. However, there have been few electrophysiological studies on brain activity after exposure to ionizing radiation (IR). A new methodological approach regarding the assessment of the possible effects of IR on brain activity is the use of linear and nonlinear mathematical methods in the analysis of complex time series, such as brain oscillations measured using the electrocorticogram (ECoG). The objective of this study was to use linear and nonlinear mathematical methods as biomarkers of gamma radiation regarding cortical electrical activity. Adult Wistar rats were divided into 3 groups: 1 control and 2 irradiated groups, evaluated at 24 h (IR24) and 90 days (IR90) after exposure to 18 Gy of gamma radiation from a cobalt-60 radiotherapy source. The ECoG was analyzed using power spectrum methods for the calculation of the power of delta, theta, alpha and beta rhythms and by means of the a-exponent of the detrended fluctuation analysis (DFA). Using both mathematical methods it was possible to identify changes in the ECoG, and to identify significant changes in the pattern of the recording at 24 h after irradiation. Some of these changes were persistent at 90 days after exposure to IR. In particular, the theta wave using the two methods showed higher sensitivity than other waves, suggesting that it is a possible biomarker of exposure to IR. (author)

  13. Long-term correlation of the electrocorticogram as a bioindicator of brain exposure to ionizing radiation.

    Science.gov (United States)

    Aguiar, L A A; Silva, I M S; Fernandes, T S; Nogueira, R A

    2015-10-01

    Understanding the effects of radiation and its possible influence on the nervous system are of great clinical interest. However, there have been few electrophysiological studies on brain activity after exposure to ionizing radiation (IR). A new methodological approach regarding the assessment of the possible effects of IR on brain activity is the use of linear and nonlinear mathematical methods in the analysis of complex time series, such as brain oscillations measured using the electrocorticogram (ECoG). The objective of this study was to use linear and nonlinear mathematical methods as biomarkers of gamma radiation regarding cortical electrical activity. Adult Wistar rats were divided into 3 groups: 1 control and 2 irradiated groups, evaluated at 24 h (IR24) and 90 days (IR90) after exposure to 18 Gy of gamma radiation from a cobalt-60 radiotherapy source. The ECoG was analyzed using power spectrum methods for the calculation of the power of delta, theta, alpha and beta rhythms and by means of the α-exponent of the detrended fluctuation analysis (DFA). Using both mathematical methods it was possible to identify changes in the ECoG, and to identify significant changes in the pattern of the recording at 24 h after irradiation. Some of these changes were persistent at 90 days after exposure to IR. In particular, the theta wave using the two methods showed higher sensitivity than other waves, suggesting that it is a possible biomarker of exposure to IR.

  14. SU-E-QI-12: Morphometry Based Measurements of the Structural Response to Whole Brain Radiation

    International Nuclear Information System (INIS)

    Fuentes, D; Castillo, R; Castillo, E; Guerrero, T

    2014-01-01

    Purpose: Although state of the art radiation therapy techniques for treating intracranial malignancies have eliminated acute brain injury, cognitive impairment occurs in 50–90% of patients who survive >6mo post irradiation. Quantitative characterization of therapy response is needed to facilitate therapeutic strategies to minimize radiation induced cognitive impairment [1]. Deformation based morphometry techniques [2, 3] are presented as a quantitative imaging biomarker of therapy response in patients receiving whole brain radiation for treating medulloblastoma. Methods: Post-irradiation magnetic resonance imaging (MRI) data sets were retrospectively analyzed in N=15 patients, >60 MR image datasets. As seen in Fig 1(a), volume changes at multiple time points post-irradiation were quantitatively measured in the cerebrum and ventricles with respect to pre-irradiation MRI. A high resolution image Template, was registered to the pre-irradiation MRI of each patient to create a brain atlas for the cerebrum, cerebellum, and ventricles. Skull stripped images for each patient were registered to the initial pre-treatment scan. Average volume changes in the labeled regions were measured using the determinant of the displacement field Jacobian. Results: Longitudinal measurements, Fig 1(b-c), show a negative correlation p=.06, of the cerebral volume change with the time interval from irradiation. A corresponding positive correlation, p=.01, between ventricular volume change and time interval from irradiation is seen. One sample t-test for correlations were computed using a Spearman method. An average decrease in cerebral volume, p=.08, and increase in ventricular volume, p<.001, was observed. The radiation dose was seen directly proportional to the induced volume changes in the cerebrum, r=−.44, p<.001, Fig 1(d). Conclusion: Results indicate that morphometric monitoring of brain tissue volume changes may potentially be used to quantitatively assess toxicity and response to

  15. SU-E-QI-12: Morphometry Based Measurements of the Structural Response to Whole Brain Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Fuentes, D; Castillo, R; Castillo, E; Guerrero, T [UT MD Anderson Cancer Center, Houston, TX (United States)

    2014-06-15

    Purpose: Although state of the art radiation therapy techniques for treating intracranial malignancies have eliminated acute brain injury, cognitive impairment occurs in 50–90% of patients who survive >6mo post irradiation. Quantitative characterization of therapy response is needed to facilitate therapeutic strategies to minimize radiation induced cognitive impairment [1]. Deformation based morphometry techniques [2, 3] are presented as a quantitative imaging biomarker of therapy response in patients receiving whole brain radiation for treating medulloblastoma. Methods: Post-irradiation magnetic resonance imaging (MRI) data sets were retrospectively analyzed in N=15 patients, >60 MR image datasets. As seen in Fig 1(a), volume changes at multiple time points post-irradiation were quantitatively measured in the cerebrum and ventricles with respect to pre-irradiation MRI. A high resolution image Template, was registered to the pre-irradiation MRI of each patient to create a brain atlas for the cerebrum, cerebellum, and ventricles. Skull stripped images for each patient were registered to the initial pre-treatment scan. Average volume changes in the labeled regions were measured using the determinant of the displacement field Jacobian. Results: Longitudinal measurements, Fig 1(b-c), show a negative correlation p=.06, of the cerebral volume change with the time interval from irradiation. A corresponding positive correlation, p=.01, between ventricular volume change and time interval from irradiation is seen. One sample t-test for correlations were computed using a Spearman method. An average decrease in cerebral volume, p=.08, and increase in ventricular volume, p<.001, was observed. The radiation dose was seen directly proportional to the induced volume changes in the cerebrum, r=−.44, p<.001, Fig 1(d). Conclusion: Results indicate that morphometric monitoring of brain tissue volume changes may potentially be used to quantitatively assess toxicity and response to

  16. Clinical course of brain stroke in the persons exposed to ionizing radiation under the production conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bouchmanov, A. [State Research Center of Russia, Moscow (Russian Federation). Inst. of Biophysics

    2000-05-01

    The purpose was to study the risk factors and clinical course of brain strokes in professionally exposed workers being employed in plutonium production in comparison with a control group. The method and materials of study -clinical supervision and clinical database creation on 162 cases of brain stroke (128 males and 34 females) developed among professionally exposed workers. Age of patient varied from 21 to 68 years (in average -51.6 y.). The control group consisted of patients with the same diagnosis, worked on the same enterprise, but non-exposed to radiation. Data on the totally accumulated dose of external gamma radiation were received on the base of the individual dosimeters (from 0.1 cSv to 52 cSv, in average about 13 cSv); the plutonium-239 body content was estimated accordingly to the level of urine radionuclide excretion (from 0.4 kBq to 1.6 kBq, in average about 0.33 kBq). Muscle's hypertinsion and pathological great-toe reflexes in paretic legs and hands, hemianopsia, impressive and ataxic aphasia prevailed in the patients with ischemic brain strokes in system of internal carotid artery, exposed to radiation. The changes of muscle's tension, ataxia and nystagmus were marked more often in the professionals with ischemic brain strokes in system of vertebrobasilar artery. The illness proceeded more easy and with smaller frequency of frustration of consciousness and algesthesia, irrespective of a type ischemic brain strokes in the people exposed to ionizing radiation, than in patients of non-irradiated group. It was found that the arterial hypertension appeared to be the main risk factor for the brain stroke in both groups of patients (in 81.48% and 91.15% of cases). There was no marked differences in significance of risk factors and in main clinical parameters of various types of ischemic brain strokes among the patients professionally exposed to radiation in comparison with a control group. (author)

  17. Brain tumors and synchrotron radiation: new methods for mini-beams radiation therapy and treatment follow-up by functional imaging

    International Nuclear Information System (INIS)

    Deman, P.

    2012-01-01

    An innovative method of synchrotron radiation therapy, called mini-beams, was proposed by A. Dilmanian et al. in 2006. Mini-beams consists in tumor irradiation with monochromatic sub-millimetric x-ray beams spatially fractionated produced by a synchrotron source. To obtain a homogeneous dose in the target volume, an interleaving is realized using two orthogonal incidences. Adjacent healthy tissue is only partially irradiated by mini-beams, the areas between the beams only receive scattered radiation and therefore the energy deposited is 10 to 15 times lower than on one mini-beam axis, leading to a sparing effect of healthy tissue even when a high dose is deposited in the target volume. The thesis project is the development of this experimental method of monochromatic mini-beams, which involves the control of the irradiation geometry, the control of dosimetry and its modeling by Monte Carlo simulations. To evaluate the method, preclinical experiments on models of brain tumors implanted in rats (F98) are performed. Follow-up by anatomical and functional imaging is carried out to evaluate the effectiveness of the treatment. Functional imaging of cerebral perfusion (volume and cerebral blood flow, mean transit time of heavy elements) appears to be associated in the literature as a relevant method for monitoring prognostic. The key parameters of the cerebral vasculature are mainly studied in magnetic resonance imaging (MRI), because of the harmlessness of this imaging modality. The relation between MRI signal and contrast agent concentration is very complex and no quantitative relationship is well known. Synchrotron Radiation Computed Tomography (SRCT) is an imaging modality with performances to measure absolute contrast agent concentration very close to the theoretical limits and can be used as gold-standard. The used pharmacokinetic models need as input parameters a contrast agent concentration versus time. A comparison of perfusion measurements between MRI and SRCT

  18. Increased seroreactivity to glioma-expressed antigen 2 in brain tumor patients under radiation.

    Directory of Open Access Journals (Sweden)

    Sabrina M Heisel

    Full Text Available BACKGROUND: Surgery and radiation are the mainstays of therapy for human gliomas that are the most common primary brain tumors. Most recently, cell culture and animal studies provided the first convincing evidence that radiation not only eliminates tumor cells, but also modulates the immune response and likely improves anti-tumor immunotherapy. METHODOLOGY/PRINCIPAL FINDINGS: We present an in vivo study that analyzes the effects of radiation on the immune response in tumor patients. As readout system, we utilized the reactivity of glioma patients' sera against antigen GLEA2 as the most frequent antigen immunogenic in glioblastoma patients. We established an ELISA assay to analyze reactivity of 24 glioblastoma patients over a period of several months. As control we used 30 sera from healthy donors as well as 30 sera from lung cancer patients. We compared the course of GLEA2 seroreactivity at different times prior, during and after radiation. The GLEA2 seroreactivity was increased by the time of surgery, decreased after surgery, increased again under radiation, and slightly decreased after radiation. CONCLUSIONS/SIGNIFICANCE: Our results provide in vivo evidence for an increased antibody response against tumor antigens under radiation. Antigens that become immunogenic with an increased antibody response as result of radiation can serve as ideal targets for immunotherapy of human tumors.

  19. Multidisciplinary approach to radiation late effects in the brain circulatory system: First results

    International Nuclear Information System (INIS)

    Keyeux, A.J.M.; Reinhold, H.S.; Gerber, G.B.; Maisin, J.R.; Reyners, H.; Gianfelici de Reyners, E.; Calvo, W.

    1976-01-01

    Although acute vascular damage and the early functional impairment of the central nervous system has been studied relatively frequently, the pathophysiological mechanisms of late radiation effects and their relevance to vascular damage, are less well investigated and are poorly understood. As the possibility of later radiation damage is a factor which limits the therapist in the radiation dose, he can give to effect a local tumour cure, it is essential that the mechanisms and importance of vascular irradiation damage be determined before late effects can either be treated or avoided. In view of the inconclusive results obtained by previous authors, it was felt that a multidisciplinary approach might better be suited to solve this problem. Thus, in 1973 a research project was initiated by EULEP to investigate the origins and consequences of radiation induced vascular changes after local irradiation of the brain. In this preliminary report, data on morphological, circulatory and biochemical parameters are presented and discussed. (GC)

  20. Adaptation of vacuum-assisted mouthpiece head immobilization system for precision infant brain radiation therapy.

    Science.gov (United States)

    Wong, Kenneth; Cheng, Justine; Bowlin, Kristine; Olch, Arthur

    Our purpose was to describe an adaptation of a commercially available mouthpiece for vacuum-assisted mouthpiece immobilization for radiation therapy in infants. An infant diagnosed with a brain tumor required radiation therapy. After reviewing dental literature about obturators, we designed a modification for the smallest commercially available mouthpiece tray. The patient was simulated with the adapted mouthpiece tray. We achieved excellent immobilization and had small daily image guided treatment position shifts. Our patient tolerated treatment well without injury to oral cavity or mucosa. Head immobilization with a vacuum-assisted modified mouthpiece has not been described in infants. Our modification is a novel and safe and permits effective and accurate immobilization for infants for radiation therapy. New manufacturing technologies may allow creation of individualized mouthpieces. Copyright © 2016 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

  1. The development and investigation of a prototype three-dimensional compensator for whole brain radiation therapy

    International Nuclear Information System (INIS)

    Keall, Paul; Arief, Isti; Shamas, Sofia; Weiss, Elisabeth; Castle, Steven

    2008-01-01

    Whole brain radiation therapy (WBRT) is the standard treatment for patients with brain metastases, and is often used in conjunction with stereotactic radiotherapy for patients with a limited number of brain metastases, as well as prophylactic cranial irradiation. The use of open fields (conventionally used for WBRT) leads to higher doses to the brain periphery if dose is prescribed to the brain center at the largest lateral radius. These dose variations potentially compromise treatment efficacy and translate to increased side effects. The goal of this research was to design and construct a 3D 'brain wedge' to compensate dose heterogeneities in WBRT. Radiation transport theory was invoked to calculate the desired shape of a wedge to achieve a uniform dose distribution at the sagittal plane for an ellipsoid irradiated medium. The calculations yielded a smooth 3D wedge design to account for the missing tissue at the peripheral areas of the brain. A wedge was machined based on the calculation results. Three ellipsoid phantoms, spanning the mean and ± two standard deviations from the mean cranial dimensions were constructed, representing 95% of the adult population. Film was placed at the sagittal plane for each of the three phantoms and irradiated with 6 MV photons, with the wedge in place. Sagittal plane isodose plots for the three phantoms demonstrated the feasibility of this wedge to create a homogeneous distribution with similar results observed for the three phantom sizes, indicating that a single wedge may be sufficient to cover 95% of the adult population. The sagittal dose is a reasonable estimate of the off-axis dose for whole brain radiation therapy. Comparing the dose with and without the wedge the average minimum dose was higher (90% versus 86%), the maximum dose was lower (107% versus 113%) and the dose variation was lower (one standard deviation 2.7% versus 4.6%). In summary, a simple and effective 3D wedge for whole brain radiotherapy has been developed

  2. Partial protection of baboons against Schistosoma mansoni using radiation-attenuated cryopreserved schistosomula

    International Nuclear Information System (INIS)

    James, E.R.; Dobinson, A.R.; Otieno, M.; Monorei, J.; Else, J.G.

    1986-01-01

    Three groups of five baboons were vaccinated in Kenya using three doses of 10,000 viable cryopreserved schistosomula attenuated with either 10, 20 or 60 krad 60 co-irradiation. The results from perfusion indicated reductions in worm burdens in the 10, 20 and 60 krad vaccinated groups of 18%, 23% and 20% respectively, none of which was statistically significant. No stunting of adult worms could be demonstrated in any of the groups. Mean tissue egg burdens were higher in all vaccinated groups and consequently egg production per worm pair was also higher than in the challenge controls. The logistics of preparing and delivering a cryopreserved radiation-attenuated vaccine were amply demonstrated; however, in this study the levels of protection achieved were not statistically significant; possible reasons for this are discussed. (author)

  3. Production and partial characterization of alkaline protease from bacillus subtilis mutant induced by gamma radiation

    International Nuclear Information System (INIS)

    Ibrahim, H.M.M.; Bashandy, A.S.

    2010-01-01

    Fourteen bacterial isolates belonging to B.subtilis were locally isolated from soil and screened for alkaline protease production. Only one strain, the highly potent one, was selected as alkaline protease producer and subjected to further studies to optimize its production. Alkaline protease production was maximum at 35 degree C after 72 h of incubation and at ph 10.0. molasses as a carbon source and combination of peptone and yeast extract as a nitrogen source enhanced greatly alkaline protease production. The mutant strain induced by gamma radiation showed higher alkaline protease production by 1.97 fold as compared with the parent strain. The alkaline protease enzyme was active at 40 degree C and ph 10. It was compatible with many commercial detergents and showed high stability (84 %) of its original activity with Ariel detergent. Moreover, alkaline protease enhanced the washing performance, and retained 95 % of its activity in the formulated dry powder.

  4. Partial radiative-recombination cross sections for excited states of hydrogen

    International Nuclear Information System (INIS)

    Fazio, P.M.; Copeland, G.E.

    1985-01-01

    The squares of the dipole and quadrupole matrix elements for the free-to-bound transitions of hydrogen up to bound states Vertical Barn = 20,l = 19> are derived in closed analytic form as a function of the kinetic energy of the free electron. Coulomb wave functions are used for the free as well as the bound states and, thus, the results are good for any electron energy. Several interesting effects are found. First, the transition probabilities are maximum for recombination into specific intermediate-angular-momentum states at low energies (w<1 eV) and where the free-state angular momentum is greater than that of the bound state. Further, that specific intermediate-angular-momentum state depends on the kinetic energy of the free electron. This behavior is in contrast to the ''normal'' behavior of the transition strengths where recombination into s states is greatest and decreases with increasing angular momentum. Second, the quadrupole matrix elements vanish for certain velocities of the free electron. These ''zeros'' produce minima in the corresponding quadrupole cross sections. Finally, the calculated partial cross sections for recombination into high-angular-momentum states are greater when quadrupole transitions are included

  5. Radiation induced early delayed changes in mice brain: a 1h MRS and behavioral evaluation study

    International Nuclear Information System (INIS)

    Gupta, Mamta; Rana, Poonam; Haridas, Seenu; Manda, Kailash; Hemanth Kumar, B.S.; Khushu, Subash

    2014-01-01

    Radiation induced CNS injury can be classified as acute, early delayed and late delayed. Most of the studies suggest that acute injury is reversible whereas early delayed and late delayed injury is irreversible leading to metabolic and cognitive impairment. Extensive research has been carried out on cranial radiation induced early and late delayed changes, there are no reports on whole body radiation induced early and delayed changes. The present study was designed to observe early delayed effects of radiation during whole body radiation exposure. A total of 20 C57 male mice were divided in two groups of 10 animals each. One group was exposed to a dose of 5 Gy whole body radiation through Tele 60 Co irradiation facility with source operating at 2.496 Gy/min, while other group served as sham irradiated control. Behavioral and MR spectroscopy was carried out 3 months post irradiation. Behavioral parameters such as locomotor activity and working memory were evaluated first then followed by MR spectroscopy at 7T animal MRI system. For MRS, voxel was localised in the cortex-hippocampus region of mouse brain. MR spectra were acquired using PRESS sequence, FID was processed using LC model for quantitation. The data showed impaired cognitive functions and altered metabolite levels during early delayed phase of whole body radiation induced injury. In behavioural experiments, there was a significant impairment in the cognitive as well as exploratory functions at 3 months post irradiation in irradiated group as compared to controls. MRS results explained changes in mI, glutamine and glx levels in irradiated animals compared to controls. Altered mI level has been found to be associated with reduced cognitive abilities in many brain disorders including MCI and Alzheimer's disease. The findings of this study suggest that whole body radiation exposure may have long lasting effect on the cognitive performance. (author)

  6. Effects of Pringle maneuver and partial hepatectomy on the pharmacokinetics and blood-brain barrier permeability of sodium fluorescein in rats.

    Science.gov (United States)

    Miah, Mohammad K; Shaik, Imam H; Bickel, Ulrich; Mehvar, Reza

    2015-08-27

    Liver diseases are known to affect the function of remote organs. The aim of the present study was to investigate the effects of Pringle maneuver, which results in hepatic ischemia-reperfusion (IR) injury, and partial hepatectomy (Hx) on the pharmacokinetics and brain distribution of sodium fluorescein (FL), which is a widely used marker of blood-brain barrier (BBB) permeability. Rats were subjected to Pringle maneuver (total hepatic ischemia) for 20 min with (HxIR) or without (IR) 70% hepatectomy. Sham-operated animals underwent laparotomy only. After 15 min or 8h of reperfusion, a single 25-mg/kg dose of FL was injected intravenously and serial (0-30 min) blood and bile and terminal brain samples were collected. Total and free (ultrafiltration) plasma, total brain homogenate, and bile concentrations of FL and/or its glucuronidated metabolite (FL-Glu) were determined by HPLC. Both IR and HxIR caused significant reductions in the biliary excretions of FL and FL-Glu, resulting in significant increases in the plasma AUC of the marker. Additionally, the free fraction of FL in plasma was significantly increased by HxIR. Although the brain concentrations of FL were increased by almost twofold in both IR and HxIR animals, the brain concentrations corrected by the free FL AUC (and not the total AUC) were similar in both groups at either time points. It is concluded that Pringle maneuver and/or partial hepatectomy substantially alters the hepatobiliary disposition, plasma AUC, plasma free fraction, and brain accumulation of FL without altering the BBB permeability to the marker. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Preclinical studies for increasing radiation response of malignant brain tumours

    International Nuclear Information System (INIS)

    Kalia, Vijay K.; Kumari, Kalyani; Sai Shyam; George, Jennifer; Shobha, A.G.; Chandrasekhar Sagar, B.K.; Lal, Jagath

    2013-01-01

    Malignant gliomas are the most common among the CNS cancers. Standard treatment for these tumours - comprises of surgery, followed by Radiotherapy (RT). Combination of Temozolomide (TMZ) increases survival, but hematological toxicities are also increased as compared to RT alone. The median survival depends on grade and location of tumour, as well as the age of the patient. Grade IV gliomas (GSMs) are third leading cause of cancer induced death in the age group of 15 to 34 years. Therefore, it is important to carry out further preclinical studies to develop more effective treatment of malignant gliomas. The present studies were carried out on different established malignant glioma cell lines. (U373MG) as well as primary monolayer cultures derived from biopsies obtained from patients with malignant gliomas. Exponentially growing cells were exposed to TMZ, Lonidamine (LND) (in 0.1% DMSO), or 2-Deoxy-D-Glucose (2-DG, aqueous solution) - with or without 60 Co-Gamma-rays (1- 2 Gy). The drugs were removed 4 hours after irradiation and the cultures were processed further for different assays of damage. Short term (4 h) treatments with TMZ 20 μM, LND 100 μM or their combination; did not induce micronuclei formation in the unirradiated cultures of U373MG cells. However, radiation (2 Gy) induced micronuclei was significantly increased by drug treatments. In primary cultures from different tumours, TMZ (≤ 10 μM) or 2-DG (1 mM), or gamma-irradiation (1-2 Gy) induced micronuclei and/ or apoptosis. The effects, however, varied in different tumours. These data show that clinically achievable, very low concentrations of these drugs could induce cellular damage and death; and increase radiosensitivity of malignant gliomas. Therefore, adjuvants like Lonidamine and 2-DG, with non-overlapping toxicities, could optimize treatment of malignant gliomas, by reducing the side effects of radio-chemotherapy. (author)

  8. Clinical significations of G2-M stage partial synchronization on radiation therapies of uterine cervical carcinomas

    International Nuclear Information System (INIS)

    Sasaki, Hiroshi

    1981-01-01

    The present study revealed that irradiation-induced changes of repopulation and redistribution played an important role in radiosensitivity and cure process of human uterine cervical carcinoma. DNA measurements by a microspectrophotometer were made on Feulgen stained biopsy specimens obtained from 20 patients. On the other hand, flow-microfluorometric measurements with Fried's computed cell cycle analysis were made on transplanted human cervical carcinomas. The mean nuclear DNA amount of human cervical carcinoma cells increased according as the irradiation doses increase until 2,000 rad. Moreover, as regards with the mean nuclear diameter of cancer cells the same phenomenon was recognized, and there was an interrelation between the increase of mean nuclear DNA amount and that of mean nuclear diameter. This phenomenon was proved in nuclear DNA analysis by flow-microfluorometric measurements on transplanted human cervical carcinoma in nude mice. Computed cell cycle analysis of F.M.F. data demonstrated that this phenomenon was due to irradiation-induced changes of repopulation and redistribution. That is to say, irradiation induces the increase of cycling cells and then partial synchronization to G2-M stage. Examination of the interrelation between this phenomenon at 500 rad and 5 years survival rate demonstrated that there was more increase of nuclear DNA amount in the good prognosis group than in the poor prognosis group. Estimation of residual cells near the G1 stage at 2,000 rad demonstrated that there were more residual cells near the G1 stage in the poor prognosis group than in the good prognosis group. (author)

  9. Postoperative Stereotactic Radiosurgery Without Whole-Brain Radiation Therapy for Brain Metastases: Potential Role of Preoperative Tumor Size

    International Nuclear Information System (INIS)

    Hartford, Alan C.; Paravati, Anthony J.; Spire, William J.; Li, Zhongze; Jarvis, Lesley A.; Fadul, Camilo E.; Rhodes, C. Harker; Erkmen, Kadir; Friedman, Jonathan; Gladstone, David J.; Hug, Eugen B.; Roberts, David W.; Simmons, Nathan E.

    2013-01-01

    Purpose: Radiation therapy following resection of a brain metastasis increases the probability of disease control at the surgical site. We analyzed our experience with postoperative stereotactic radiosurgery (SRS) as an alternative to whole-brain radiotherapy (WBRT), with an emphasis on identifying factors that might predict intracranial disease control and overall survival (OS). Methods and Materials: We retrospectively reviewed all patients through December 2008, who, after surgical resection, underwent SRS to the tumor bed, deferring WBRT. Multiple factors were analyzed for time to intracranial recurrence (ICR), whether local recurrence (LR) at the surgical bed or “distant” recurrence (DR) in the brain, for time to WBRT, and for OS. Results: A total of 49 lesions in 47 patients were treated with postoperative SRS. With median follow-up of 9.3 months (range, 1.1-61.4 months), local control rates at the resection cavity were 85.5% at 1 year and 66.9% at 2 years. OS rates at 1 and 2 years were 52.5% and 31.7%, respectively. On univariate analysis (preoperative) tumors larger than 3.0 cm exhibited a significantly shorter time to LR. At a cutoff of 2.0 cm, larger tumors resulted in significantly shorter times not only for LR but also for DR, ICR, and salvage WBRT. While multivariate Cox regressions showed preoperative size to be significant for times to DR, ICR, and WBRT, in similar multivariate analysis for OS, only the graded prognostic assessment proved to be significant. However, the number of intracranial metastases at presentation was not significantly associated with OS nor with other outcome variables. Conclusions: Larger tumor size was associated with shorter time to recurrence and with shorter time to salvage WBRT; however, larger tumors were not associated with decrements in OS, suggesting successful salvage. SRS to the tumor bed without WBRT is an effective treatment for resected brain metastases, achieving local control particularly for tumors up to

  10. Multi-institutional Nomogram Predicting Survival Free From Salvage Whole Brain Radiation After Radiosurgery in Patients With Brain Metastases

    International Nuclear Information System (INIS)

    Gorovets, Daniel; Ayala-Peacock, Diandra; Tybor, David J.; Rava, Paul; Ebner, Daniel; Cielo, Deus; Norén, Georg; Wazer, David E.; Chan, Michael; Hepel, Jaroslaw T.

    2017-01-01

    Purpose: Optimal patient selection for stereotactic radiosurgery (SRS) as the initial treatment for brain metastases is complicated and controversial. This study aimed to develop a nomogram that predicts survival without salvage whole brain radiation therapy (WBRT) after upfront SRS. Methods and Materials: Multi-institutional data were analyzed from 895 patients with 2095 lesions treated with SRS without prior or planned WBRT. Cox proportional hazards regression model was used to identify independent pre-SRS predictors of WBRT-free survival, which were integrated to build a nomogram that was subjected to bootstrap validation. Results: Median WBRT-free survival was 8 months (range, 0.1-139 months). Significant independent predictors for inferior WBRT-free survival were age (hazard ratio [HR] 1.1 for each 10-year increase), HER2(−) breast cancer (HR 1.6 relative to other histologic features), colorectal cancer (HR 1.4 relative to other histologic features), increasing number of brain metastases (HR 1.09, 1.32, 1.37, and 1.87 for 2, 3, 4, and 5+ lesions, respectively), presence of neurologic symptoms (HR 1.26), progressive systemic disease (HR 1.35), and increasing extracranial disease burden (HR 1.31 for oligometastatic and HR 1.56 for widespread). Additionally, HER2(+) breast cancer (HR 0.81) and melanoma (HR 1.11) trended toward significance. The independently weighted hazard ratios were used to create a nomogram to display estimated probabilities of 6-month and 12-month WBRT-free survival with a corrected Harrell's C concordance statistic of 0.62. Conclusions: Our nomogram can be used at initial evaluation to help select patients best suited for upfront SRS for brain metastases while reducing expense and morbidity in patients who derive minimal or no benefit.

  11. Multi-institutional Nomogram Predicting Survival Free From Salvage Whole Brain Radiation After Radiosurgery in Patients With Brain Metastases

    Energy Technology Data Exchange (ETDEWEB)

    Gorovets, Daniel [Department of Radiation Oncology, Rhode Island Hospital, Brown University Warren Alpert Medical School, Providence, Rhode Island (United States); Department of Radiation Oncology, Perlmutter Cancer Center, NYU School of Medicine, New York, New York (United States); Ayala-Peacock, Diandra [Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, North Carolina (United States); Department of Radiation Oncology, Vanderbilt University School of Medicine, Nashville, Tennessee (United States); Tybor, David J. [Department of Public Health and Community Medicine, Tufts University School of Medicine, Boston, Massachusetts (United States); Rava, Paul [Department of Radiation Oncology, Rhode Island Hospital, Brown University Warren Alpert Medical School, Providence, Rhode Island (United States); Department of Radiation Oncology, UMass Memorial Medical Center, University of Massachusetts School of Medicine, Worcester, Massachusetts (United States); Ebner, Daniel [Department of Radiation Oncology, Rhode Island Hospital, Brown University Warren Alpert Medical School, Providence, Rhode Island (United States); Cielo, Deus; Norén, Georg [Department of Neurosurgery, Rhode Island Hospital, Brown University Warren Alpert Medical School, Providence, Rhode Island (United States); Wazer, David E. [Department of Radiation Oncology, Rhode Island Hospital, Brown University Warren Alpert Medical School, Providence, Rhode Island (United States); Chan, Michael [Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, North Carolina (United States); Hepel, Jaroslaw T., E-mail: jhepel@lifespan.org [Department of Radiation Oncology, Rhode Island Hospital, Brown University Warren Alpert Medical School, Providence, Rhode Island (United States)

    2017-02-01

    Purpose: Optimal patient selection for stereotactic radiosurgery (SRS) as the initial treatment for brain metastases is complicated and controversial. This study aimed to develop a nomogram that predicts survival without salvage whole brain radiation therapy (WBRT) after upfront SRS. Methods and Materials: Multi-institutional data were analyzed from 895 patients with 2095 lesions treated with SRS without prior or planned WBRT. Cox proportional hazards regression model was used to identify independent pre-SRS predictors of WBRT-free survival, which were integrated to build a nomogram that was subjected to bootstrap validation. Results: Median WBRT-free survival was 8 months (range, 0.1-139 months). Significant independent predictors for inferior WBRT-free survival were age (hazard ratio [HR] 1.1 for each 10-year increase), HER2(−) breast cancer (HR 1.6 relative to other histologic features), colorectal cancer (HR 1.4 relative to other histologic features), increasing number of brain metastases (HR 1.09, 1.32, 1.37, and 1.87 for 2, 3, 4, and 5+ lesions, respectively), presence of neurologic symptoms (HR 1.26), progressive systemic disease (HR 1.35), and increasing extracranial disease burden (HR 1.31 for oligometastatic and HR 1.56 for widespread). Additionally, HER2(+) breast cancer (HR 0.81) and melanoma (HR 1.11) trended toward significance. The independently weighted hazard ratios were used to create a nomogram to display estimated probabilities of 6-month and 12-month WBRT-free survival with a corrected Harrell's C concordance statistic of 0.62. Conclusions: Our nomogram can be used at initial evaluation to help select patients best suited for upfront SRS for brain metastases while reducing expense and morbidity in patients who derive minimal or no benefit.

  12. Effects of heavy-ion radiation on the brain vascular system

    International Nuclear Information System (INIS)

    Yang, T.C.; Craise, L.M.; Tobias, C.A.

    1985-01-01

    In the laboratory, the authors have been studying the effects of heavy-ion radiation on the vascular system, using neonatal rats as a model system. They investigated the response of the brain vascular system to ionizing radiation and found that distinct petechial hemorrhages developed in the cerebral cortex within a few hours after irradiation, reached a maximum after about 13 to 24 hours, and then decreased exponentially with time. No brain hemorrhage was found in neonatal rats 12 days after irradiation. Heavy ions induce more hemorrhages than x rays for a given dose, and the RBE for 670-MeV/u neon particles ranges from about 2.0 for low doses to about 1.4 for high doses

  13. Effect of MgSO4 on the contents of Ca2+ in brain cell and NO in brain tissue of rats with radiation-induced acute brain injury

    International Nuclear Information System (INIS)

    Yuan Wenjia; Cui Fengmei; Liu Ping; He Chao; Tu Yu; Wang Lili

    2009-01-01

    The work is to explore the protection of magnesium sulfate(MgSO 4 ) on radiation-induced acute brain injury. Thirty six mature Sprague-Dawley(SD) rats were randomly divided into 3 groups of control, experimental control and experimental therapy group. The whole brains of SD rats of experimental control and experimental therapy group were irradiated with a dose of 20 Gy using 6 MeV electron beam. MgSO 4 was injected into the abdomen of experimental therapy rats group 1 day before, immediately and continue for 5 days after irradiation respectively. The brain tissues were taken on 3, 10, 17 and 24 d after irradiation. Ca 2+ content in brain cell was measured by laser scanning confocal microscopy, and the NO content in brain tissue was detected by the method of nitric acid reductase. Compared with the blank control group, the contents of Ca 2+ in brain cell and NO in brain tissue of the experimental control group increase (P 4 used in early stage can inhibit the contents of Ca 2+ in brain cell and NO in brain tissue after radiation-induced acute brain injury. It means that MgSO 4 has a protective effect on radiation-induced acute brain injury. (authors)

  14. Exposure of cultured astroglial and microglial brain cells to 900 MHz microwave radiation.

    Science.gov (United States)

    Thorlin, Thorleif; Rouquette, Jean-Michel; Hamnerius, Yngve; Hansson, Elisabeth; Persson, Mikael; Björklund, Ulrika; Rosengren, Lars; Rönnbäck, Lars; Persson, Mikael

    2006-08-01

    The rapid rise in the use of mobile communications has raised concerns about health issues related to low-level microwave radiation. The head and brain are usually the most exposed targets in mobile phone users. In the brain, two types of glial cells, the astroglial and the microglial cells, are interesting in the context of biological effects from microwave exposure. These cells are widely distributed in the brain and are directly involved in the response to brain damage as well as in the development of brain cancer. The aim of the present study was to investigate whether 900 MHz radiation could affect these two different glial cell types in culture by studying markers for damage-related processes in the cells. Primary cultures enriched in astroglial cells were exposed to 900 MHz microwave radiation in a temperature-controlled exposure system at specific absorption rates (SARs) of 3 W/kg GSM modulated wave (mw) for 4, 8 and 24 h or 27 W/kg continuous wave (cw) for 24 h, and the release into the extracellular medium of the two pro-inflammatory cytokines interleukin 6 (Il6) and tumor necrosis factor-alpha (Tnfa) was analyzed. In addition, levels of the astroglial cell-specific reactive marker glial fibrillary acidic protein (Gfap), whose expression dynamics is different from that of cytokines, were measured in astroglial cultures and in astroglial cell-conditioned cell culture medium at SARs of 27 and 54 W/kg (cw) for 4 or 24 h. No significant differences could be detected for any of the parameters studied at any time and for any of the radiation characteristics. Total protein levels remained constant during the experiments. Microglial cell cultures were exposed to 900 MHz radiation at an SAR of 3 W/kg (mw) for 8 h, and I16, Tnfa, total protein and the microglial reactivity marker ED-1 (a macrophage activation antigen) were measured. No significant differences were found. The morphology of the cultured astroglial cells and microglia was studied and appeared to be

  15. Physics strategies for sparing neural stem cells during whole-brain radiation treatments

    International Nuclear Information System (INIS)

    Kirby, Neil; Chuang, Cynthia; Pouliot, Jean; Hwang, Andrew; Barani, Igor J.

    2011-01-01

    Purpose: Currently, there are no successful long-term treatments or preventive strategies for radiation-induced cognitive impairments, and only a few possibilities have been suggested. One such approach involves reducing the dose to neural stem cell compartments (within and outside of the hippocampus) during whole-brain radiation treatments for brain metastases. This study investigates the fundamental physics issues associated with the sparing of neural stem cells during photon radiotherapy for brain metastases. Methods: Several factors influence the stem cell dose: intracranial scattering, collimator leakage, beam energy, and total number of beams. The relative importance of these factors is investigated through a set of radiation therapy plans, which are all variations of an initial 6 MV intensity-modulated radiation therapy (IMRT) plan designed to simultaneously deliver a whole-brain dose of 30 Gy and maximally reduce stem cell compartment dose. Additionally, an in-house leaf segmentation algorithm was developed that utilizes jaw motion to minimize the collimator leakage. Results: The plans are all normalized such that 50% of the PTV receives 30 Gy. For the initial 6 MV IMRT plan, 50% of the stem cells receive a dose greater than 6.3 Gy. Calculations indicate that 3.6 Gy of this dose originates from intracranial scattering. The jaw-tracking segmentation algorithm, used in conjunction with direct machine parameter optimization, reduces the 50% stem cell dose to 4.3 and 3.7 Gy for 6 and 10 MV treatment beams, respectively. Conclusions: Intracranial scattering alone is responsible for a large dose contribution to the stem cell compartment. It is, therefore, important to minimize other contributing factors, particularly the collimator leakage, to maximally reduce dose to these critical structures. The use of collimator jaw tracking in conjunction with modern collimators can minimize this leakage.

  16. Synchrotron radiation imaging is a powerful tool to image brain microvasculature

    International Nuclear Information System (INIS)

    Zhang, Mengqi; Sun, Danni; Xie, Yuanyuan; Xia, Jian; Long, Hongyu; Hu, Kai; Xiao, Bo; Peng, Guanyun

    2014-01-01

    Synchrotron radiation (SR) imaging is a powerful experimental tool for micrometer-scale imaging of microcirculation in vivo. This review discusses recent methodological advances and findings from morphological investigations of cerebral vascular networks during several neurovascular pathologies. In particular, it describes recent developments in SR microangiography for real-time assessment of the brain microvasculature under various pathological conditions in small animal models. It also covers studies that employed SR-based phase-contrast imaging to acquire 3D brain images and provide detailed maps of brain vasculature. In addition, a brief introduction of SR technology and current limitations of SR sources are described in this review. In the near future, SR imaging could transform into a common and informative imaging modality to resolve subtle details of cerebrovascular function

  17. Synchrotron radiation imaging is a powerful tool to image brain microvasculature

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Mengqi; Sun, Danni; Xie, Yuanyuan; Xia, Jian; Long, Hongyu; Hu, Kai; Xiao, Bo, E-mail: csuxiaobo123456@163.com [Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008 (China); Peng, Guanyun [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2014-03-15

    Synchrotron radiation (SR) imaging is a powerful experimental tool for micrometer-scale imaging of microcirculation in vivo. This review discusses recent methodological advances and findings from morphological investigations of cerebral vascular networks during several neurovascular pathologies. In particular, it describes recent developments in SR microangiography for real-time assessment of the brain microvasculature under various pathological conditions in small animal models. It also covers studies that employed SR-based phase-contrast imaging to acquire 3D brain images and provide detailed maps of brain vasculature. In addition, a brief introduction of SR technology and current limitations of SR sources are described in this review. In the near future, SR imaging could transform into a common and informative imaging modality to resolve subtle details of cerebrovascular function.

  18. High vulnerability of the developing fetal brain to ionizing radiation and hyperthermia

    International Nuclear Information System (INIS)

    Kameyama, Yoshiro

    1989-01-01

    The developing brain is one of the fetal structures most susceptible to environmental teratogenic insults, because of its long-lasting sensitive period extending from the beginning of embryonic organogenesis to the postnatal infantile period, the great vulnerability of undifferentiated neural cells to a wide range of environmental agents, and the lack of further reproductive capacity of neurons. Among the environmental agents which affect the developing brain, ionizing radiation and hyperthermia are regarded as the most important physical agents. The most prevalent disorders of the brain produced are histogenetic ones such as a deficit of cortical neurons, disorganized cortical architecture, and poor dendritic arborization of the cortical neurons. In this review, emphasis is given to a review of studies on the critical development stage for the induction of histogenetic disorders of the cerebral cortex and on the high vulnerability of developing neuronal cells to the two physical environmental agents mentioned. (author) 59 refs

  19. The impact of dose calculation algorithms on partial and whole breast radiation treatment plans

    International Nuclear Information System (INIS)

    Basran, Parminder S; Zavgorodni, Sergei; Berrang, Tanya; Olivotto, Ivo A; Beckham, Wayne

    2010-01-01

    This paper compares the calculated dose to target and normal tissues when using pencil beam (PBC), superposition/convolution (AAA) and Monte Carlo (MC) algorithms for whole breast (WBI) and accelerated partial breast irradiation (APBI) treatment plans. Plans for 10 patients who met all dosimetry constraints on a prospective APBI protocol when using PBC calculations were recomputed with AAA and MC, keeping the monitor units and beam angles fixed. Similar calculations were performed for WBI plans on the same patients. Doses to target and normal tissue volumes were tested for significance using the paired Student's t-test. For WBI plans the average dose to target volumes when using PBC calculations was not significantly different than AAA calculations, the average PBC dose to the ipsilateral breast was 10.5% higher than the AAA calculations and the average MC dose to the ipsilateral breast was 11.8% lower than the PBC calculations. For ABPI plans there were no differences in dose to the planning target volume, ipsilateral breast, heart, ipsilateral lung, or contra-lateral lung. Although not significant, the maximum PBC dose to the contra-lateral breast was 1.9% higher than AAA and the PBC dose to the clinical target volume was 2.1% higher than AAA. When WBI technique is switched to APBI, there was significant reduction in dose to the ipsilateral breast when using PBC, a significant reduction in dose to the ipsilateral lung when using AAA, and a significant reduction in dose to the ipsilateral breast and lung and contra-lateral lung when using MC. There is very good agreement between PBC, AAA and MC for all target and most normal tissues when treating with APBI and WBI and most of the differences in doses to target and normal tissues are not clinically significant. However, a commonly used dosimetry constraint, as recommended by the ASTRO consensus document for APBI, that no point in the contra-lateral breast volume should receive >3% of the prescribed dose needs

  20. The role of stereotactic radiation therapy in the management of children with brain tumors.

    Science.gov (United States)

    Lew, C M; LaVally, B

    1995-10-01

    Conventional radiation therapy plays an important role in the management of intracranial tumors in children. For certain tumors radiation therapy serves as the primary mode of treatment, and for others it plays an adjuvant role with surgery and/or chemotherapy. Improvements in long-term survival rates have focused attention on the long-term sequelae of brain tumors and their treatment, and the sequelae, in turn, have become important targets for clinical investigation. Long-term side effects of particular concern in children include cranial nerve damage, memory and intellectual deficits, pituitary-hypothalamic dysfunction, demyelinization of brain tissue, and secondary malignancies. A new form of radiation therapy, stereotactic radiotherapy (SRT), merges the technologies of stereotactic surgery and conventional fractionated radiotherapy. The intent is to deliver maximum tumoricidal doses to the target while limiting the dose to normal surrounding brain tissue. The key feature of SRT is a noninvasive, relocatable immobilization system to assure accurate and reproducible positioning during planning and treatment. The headframes used for children have been modified to address their specific needs. The complexities of this process require careful preparation of patients and their families and the participation of many disciplines. Long-term follow-up will be essential to evaluate the effectiveness of this innovative treatment.

  1. Effects of heavy ion radiation on the brain vascular system and embryonic development

    Science.gov (United States)

    Yang, T. C.; Tobias, C. A.

    Using neonatal rats as a model system, we investigated the response of the brain vascular system to ionizing radiation and found that distinct petechial hemorrages developed in the cerebral cortex within a few hours after irradiation, reached a maximum about 13 to 24 hours, and decreased exponentially with time. No brain hemorrhage was found in neonatal rats 12 days after irradiation. Our experimental results indicate that a dose of a few hundred rad of X rays can induce a significant number of hemorrhages in the brain, and the number of lesions increases exponentially with dose. Heavy ions induce more hemorrhages than X rays for a given dose, and the RBE for 670 MeV/u neon particles ranges from about 2.0 for low doses to about 1.4 for high doses. A histological study on the hemorrhages indicates that a large number of red blood cells leak from the blood vessels. The radiation-induced hemorrhages may be a result of some capillary membrane damages or reproductive death of some blood vessel epithelial cells. The fast onset of hemorrhage after irradiation suggests that some membrane damage may be involved. The effect of heavy-ion radiation on the embryonic development was studied with energetic iron particles. Pregnant mice were whole-body irradiated with 600 MeV/u iron particles on day 6 of gestation and were sacrificed 12 days after irradiation. Various physical abnormalities were observed, and embryos irradiated with 1 rad iron particles showed retardation of body development.

  2. Prediction of clinical depression scores and detection of changes in whole-brain using resting-state functional MRI data with partial least squares regression.

    Directory of Open Access Journals (Sweden)

    Kosuke Yoshida

    Full Text Available In diagnostic applications of statistical machine learning methods to brain imaging data, common problems include data high-dimensionality and co-linearity, which often cause over-fitting and instability. To overcome these problems, we applied partial least squares (PLS regression to resting-state functional magnetic resonance imaging (rs-fMRI data, creating a low-dimensional representation that relates symptoms to brain activity and that predicts clinical measures. Our experimental results, based upon data from clinically depressed patients and healthy controls, demonstrated that PLS and its kernel variants provided significantly better prediction of clinical measures than ordinary linear regression. Subsequent classification using predicted clinical scores distinguished depressed patients from healthy controls with 80% accuracy. Moreover, loading vectors for latent variables enabled us to identify brain regions relevant to depression, including the default mode network, the right superior frontal gyrus, and the superior motor area.

  3. A Phase I Study of Short-Course Accelerated Whole Brain Radiation Therapy for Multiple Brain Metastases

    Energy Technology Data Exchange (ETDEWEB)

    Caravatta, Luciana; Deodato, Francesco; Ferro, Marica [Department of Radiation Oncology, Fondazione di Ricerca e Cura ' Giovanni Paolo II' , Universita Cattolica del S. Cuore, Campobasso (Italy); Macchia, Gabriella, E-mail: gmacchia@rm.unicatt.it [Department of Radiation Oncology, Fondazione di Ricerca e Cura ' Giovanni Paolo II' , Universita Cattolica del S. Cuore, Campobasso (Italy); Massaccesi, Mariangela [Department of Radiation Oncology, Fondazione di Ricerca e Cura ' Giovanni Paolo II' , Universita Cattolica del S. Cuore, Campobasso (Italy); Cilla, Savino [Medical Physics Unit, Fondazione di Ricerca e Cura ' Giovanni Paolo II,' Universita Cattolica del S. Cuore, Campobasso (Italy); Padula, Gilbert D.A. [Department of Radiation Oncology, The Lacks Cancer Center Saint Mary' s Health Care, Grand Rapids, Michigan (United States); Mignogna, Samantha; Tambaro, Rosa [Department of Palliative Therapies, Fondazione di Ricerca e Cura ' Giovanni Paolo II' , Universita Cattolica del S. Cuore, Campobasso (Italy); Carrozza, Francesco [Department of Oncology, A. Cardarelli Hospital, Campobasso (Italy); Flocco, Mariano [Madre Teresa di Calcutta Hospice, Larino (Italy); Cantore, Giampaolo [Department of Neurological Sciences, Istituto Neurologico Mediterraneo Neuromed, Istituto di Ricovero e Cura a Carattere Scientifico, Pozzilli (Italy); Scapati, Andrea [Department of Radiation Oncology, ' San Francesco' Hospital, Nuoro (Italy); Buwenge, Milly [Department of Radiotherapy, Mulago Hospital, Kampala (Uganda); and others

    2012-11-15

    Purpose: To define the maximum tolerated dose (MTD) of a SHort-course Accelerated whole brain RadiatiON therapy (SHARON) in the treatment of patients with multiple brain metastases. Methods and Materials: A phase 1 trial in 4 dose-escalation steps was designed: 12 Gy (3 Gy per fraction), 14 Gy (3.5 Gy per fraction), 16 Gy (4 Gy per fraction), and 18 Gy (4.5 Gy per fraction). Eligibility criteria included patients with unfavorable recursive partitioning analysis (RPA) class > or =2 with at least 3 brain metastases or metastatic disease in more than 3 organ systems, and Eastern Cooperative Oncology Group (ECOG) performance status {<=}3. Treatment was delivered in 2 days with twice-daily fractionation. Patients were treated in cohorts of 6-12 to define the MTD. The dose-limiting toxicity (DLT) was defined as any acute toxicity {>=}grade 3, according to the Radiation Therapy Oncology Group scale. Information on the status of the main neurologic symptoms and quality of life were recorded. Results: Characteristics of the 49 enrolled patients were as follows: male/female, 30/19; median age, 66 years (range, 23-83 years). ECOG performance status was <3 in 46 patients (94%). Fourteen patients (29%) were considered to be in recursive partitioning analysis (RPA) class 3. Grade 1-2 acute neurologic (26.4%) and skin (18.3%) toxicities were recorded. Only 1 patient experienced DLT (neurologic grade 3 acute toxicity). With a median follow-up time of 5 months (range, 1-23 months), no late toxicities have been observed. Three weeks after treatment, 16 of 21 symptomatic patients showed an improvement or resolution of presenting symptoms (overall symptom response rate, 76.2%; confidence interval 0.95: 60.3-95.9%). Conclusions: Short-course accelerated radiation therapy in twice-daily fractions for 2 consecutive days is tolerated up to a total dose of 18 Gy. A phase 2 study has been planned to evaluate the efficacy on overall survival, symptom control, and quality of life indices.

  4. Intensity Modulated Radiation Therapy With Simultaneous Integrated Boost in Patients With Brain Oligometastases: A Phase 1 Study (ISIDE-BM-1)

    Energy Technology Data Exchange (ETDEWEB)

    Ferro, Marica [Radiotherapy Unit, Fondazione di Ricerca e Cura “Giovanni Paolo II,” Catholic University of Sacred Heart, Campobasso (Italy); Chiesa, Silvia [Department of Radiotherapy, Fondazione Policlinico Universitario “A. Gemelli,” Catholic University of Sacred Heart, Rome (Italy); Macchia, Gabriella, E-mail: gmacchia@rm.unicatt.it [Radiotherapy Unit, Fondazione di Ricerca e Cura “Giovanni Paolo II,” Catholic University of Sacred Heart, Campobasso (Italy); Cilla, Savino [Medical Physics Unit, Fondazione di Ricerca e Cura “Giovanni Paolo II,” Catholic University of Sacred Heart, Campobasso (Italy); Bertini, Federica [Radiation Oncology Center, Department of Experimental, Diagnostic and Specialty Medicine, S. Orsola-Malpighi Hospital, University of Bologna, Bologna (Italy); Frezza, Giovanni [Radiotherapy Department, Ospedale Bellaria, Bologna (Italy); Farioli, Andrea [Department of Medical and Surgical Sciences, S. Orsola-Malpighi Hospital, University of Bologna, Bologna (Italy); Cammelli, Silvia [Radiation Oncology Center, Department of Experimental, Diagnostic and Specialty Medicine, S. Orsola-Malpighi Hospital, University of Bologna, Bologna (Italy); Balducci, Mario [Department of Radiotherapy, Fondazione Policlinico Universitario “A. Gemelli,” Catholic University of Sacred Heart, Rome (Italy); Ianiro, Anna [Medical Physics Unit, Fondazione di Ricerca e Cura “Giovanni Paolo II,” Catholic University of Sacred Heart, Campobasso (Italy); Angelini, Anna Lisa; Compagnone, Gaetano [Medical Physics Unit, S. Orsola-Malpighi Hospital, Bologna (Italy); and others

    2017-01-01

    Purpose: To investigate the maximum tolerated dose of intensity modulated radiation therapy simultaneous integrated boost whole-brain radiation therapy for palliative treatment of patients with <5 brain metastases using a standard linear accelerator. Materials and Methods: The whole brain plus 3-mm margin was defined as the planning target volume (PTV{sub wb}), whereas each brain metastasis, defined as the contrast-enhancing tumor on MRI T1 scans, plus a 3-mm isotropic margin, was defined as metastases PTV (PTV{sub m}). Radiation therapy was delivered in 10 daily fractions (2 weeks). Only the dose to PTV{sub m} was progressively increased in the patient cohorts (35 Gy, 40 Gy, 45 Gy, 50 Gy), whereas the PTV{sub wb} was always treated with 30 Gy (3 Gy per fraction) in all patients. The dose-limiting toxicity was evaluated providing that 3 months of follow-up had occurred after the treatment of a 6-patient cohort. Results: Thirty patients were enrolled in the study (dose PTV{sub m}: 35 Gy, 8 patients; 40 Gy, 6 patients; 45 Gy, 6 patients; 50 Gy, 10 patients). The number of treated brain metastases was 1 in 18 patients, 2 in 5 patients, 3 in 6 patients, and 4 in 1 patient. Three patients experienced dose-limiting toxicity: 1 patient at dose level 2 presented grade 3 (G3) skin toxicity; 1 patient at dose level 4 presented G3 neurologic toxicity; and 1 patient at the same level showed brain hemorrhage. Most patients showed G1 to 2 acute toxicity, in most cases skin (n=19) or neurologic (n=10). Twenty-seven were evaluable for response: 6 (22%) stable disease, 18 (67%) partial response, and 3 (11%) complete response. Median survival and 1-year overall survival were 12 months and 53%, respectively. No patient showed late toxicity. Conclusions: In this first prospective trial on the use of intensity modulated radiation therapy simultaneous integrated boost delivered with a standard linear accelerator in patients with brain oligometastases, a boost dose up to 50

  5. A Phase III Study of Conventional Radiation Therapy Plus Thalidomide Versus Conventional Radiation Therapy for Multiple Brain Metastases (RTOG 0118)

    International Nuclear Information System (INIS)

    Knisely, Jonathan P.S.; Berkey, Brian; Chakravarti, Arnab; Yung, Al W.K.; Curran, Walter J.; Robins, H. Ian; Movsas, Benjamin; Brachman, David G.; Henderson, Randall H.; Mehta, Minesh P.

    2008-01-01

    Purpose: To compare whole-brain radiation therapy (WBRT) with WBRT combined with thalidomide for patients with brain metastases not amenable to resection or radiosurgery. Patients and Methods: Patients with Zubrod performance status 0-1, MRI-documented multiple (>3), large (>4 cm), or midbrain brain metastases arising from a histopathologically confirmed extracranial primary tumor, and an anticipated survival of >8 weeks were randomized to receive WBRT to a dose of 37.5 Gy in 15 fractions with or without thalidomide during and after WBRT. Prerandomization stratification used Radiation Therapy Oncology Group (RTOG) Recursive Partitioning Analysis (RPA) Class and whether post-WBRT chemotherapy was planned. Endpoints included overall survival, progression-free survival, time to neurocognitive progression, the cause of death, toxicities, and quality of life. A protocol-planned interim analysis documented that the trial had an extremely low probability of ever showing a significant difference favoring the thalidomide arm given the results at the time of the analysis, and it was therefore closed on the basis of predefined statistical guidelines. Results: Enrolled in the study were 332 patients. Of 183 accrued patients, 93 were randomized to receive WBRT alone and 90 to WBRT and thalidomide. Median survival was 3.9 months for both arms. No novel toxicities were seen, but thalidomide was not well tolerated in this population. Forty-eight percent of patients discontinued thalidomide because of side effects. Conclusion: Thalidomide provided no survival benefit for patients with multiple, large, or midbrain metastases when combined with WBRT; nearly half the patients discontinued thalidomide due to side effects

  6. Molecular targets in radiation-induced blood-brain barrier disruption

    International Nuclear Information System (INIS)

    Nordal, Robert A.; Wong, C. Shun

    2005-01-01

    Disruption of the blood-brain barrier (BBB) is a key feature of radiation injury to the central nervous system. Studies suggest that endothelial cell apoptosis, gene expression changes, and alteration of the microenvironment are important in initiation and progression of injury. Although substantial effort has been directed at understanding the impact of radiation on endothelial cells and oligodendrocytes, growing evidence suggests that other cell types, including astrocytes, are important in responses that include induced gene expression and microenvironmental changes. Endothelial apoptosis is important in early BBB disruption. Hypoxia and oxidative stress in the later period that precedes tissue damage might lead to astrocytic responses that impact cell survival and cell interactions. Cell death, gene expression changes, and a toxic microenvironment can be viewed as interacting elements in a model of radiation-induced disruption of the BBB. These processes implicate particular genes and proteins as targets in potential strategies for neuroprotection

  7. Primary lymphoma of brain: results of management of a modern cohort with radiation therapy

    International Nuclear Information System (INIS)

    Laperriere, Normand J.; Cerezo, Laura; Milosevic, Michael F.; Wong, C. Shun; Patterson, Bruce; Panzarella, Tony

    1997-01-01

    Purpose: To assess the outcome and prognostic factors for patients with primary lymphoma of brain managed with radiation therapy between 1979 and 1988. Methods and materials: A retrospective review was undertaken of 49 patients referred to Princess Margaret Hospital. There were 25 males and 24 females. Median age was 60 years, with a range of 17-80 years. Tumors were located supratentorially in 35, infratentorially in 10, and both in 4 patients. Single masses were demonstrated on CT brain in 36, and multiple lesions in 13 patients. Cranial irradiation was given in 48, and 11 patients received chemotherapy. All patients in this series were immunocompetent. Results: Over a follow-up range of 3-11 years of surviving patients, with a median of 6 years, (40(49)) patients have died. Overall median survival was 1.4 years (17 months) and 5-year actuarial survival was 26%. Statistical analysis revealed the following significant factors: Karnofsky performance status (KPS), age, and distribution pattern of disease on presenting CT brain. Five-year actuarial survival for patients with a KPS > 60 or 60, 5-year actuarial survival was 42% and 9%, respectively (P = 0.03); for patients with solitary or multiple lesions, 5-year actuarial survival was 30% and 15%, respectively (P = 0.04). Conclusions: We conclude that Karnofsky performance status, age, and distribution pattern on pretreatment CT of brain are significant prognostic factors in primary lymphoma of brain, and that new approaches need to be developed for these patients

  8. Time- and dose-dependent changes in neuronal activity produced by X radiation in brain slices

    International Nuclear Information System (INIS)

    Pellmar, T.C.; Schauer, D.A.; Zeman, G.H.

    1990-01-01

    A new method of exposing tissues to X rays in a lead Faraday cage has made it possible to examine directly radiation damage to isolated neuronal tissue. Thin slices of hippocampus from brains of euthanized guinea pigs were exposed to 17.4 ke V X radiation. Electrophysiological recordings were made before, during, and after exposure to doses between 5 and 65 Gy at a dose rate of 1.54 Gy/min. Following exposure to doses of 40 Gy and greater, the synaptic potential was enhanced, reaching a steady level soon after exposure. The ability of the synaptic potential to generate a spike was reduced and damage progressed after termination of the radiation exposure. Recovery was not observed following termination of exposure. These results demonstrate that an isolated neuronal network can show complex changes in electrophysiological properties following moderate doses of ionizing radiation. An investigation of radiation damage directly to neurons in vitro will contribute to the understanding of the underlying mechanisms of radiation-induced nervous system dysfunction

  9. Experimental studies on pathogenesis of the brain radiation injury in early stage

    International Nuclear Information System (INIS)

    Ye Tian; Shiyao Bao; Weibo Yin; Chunfeng Liu; Zhilin Zhang

    2000-01-01

    To investigate the pathogenesis of the brain radiation injury in the early stage, a series of experiments were performed as below. The SD rats halfbrain were irradiated by the single dose of 10, 20, and 30 Gy of 4 MeV electron, all those experiments were performed in 1 day to 3 months after radiation. The neurological symptoms, the weight and the skin response inside the field of all the rats were evaluated sequentially. The measurement of regional cerebral blood flow (rCBF) using hydrogen gas generated by electrolysis, the calculation of the brain water content percentage with wet-dry weight formula. The DNA contents and the quantities of bcl-2 protein were analyzed by flow cytometry. The brain histological sections were scanned to assess the present or absence of white matter necrosis in the region of hippocampus, and then the hippocampus region was observed for the morphological changes of the blood vessel, neuroglial, and the neurons. Some of the data were analyzed by the Student t test. Intra-portal alopecia was observed in all rats which received 30 Gy and some rats which received 20 Gy, the abnormal neurological signs were not found in all the rats, but the tend of weight increase was less pronounced in 1-3 months in the irradiated rats than those unirradiated. By comparison the unirradiated hemisphere, the rCBF of the contralateral brain decreased in most of the rats. In 20 Gy and 30 Gy groups, rCBF decreased areas expand gradually along with the prolong of observation time, from the nucleus caudate putamen, to the frontal cortex and then the hippocampus, the rCBF of whole the irradiated hemibrain was reduced significantly at 3 month after radiation. The water content of the irradiated halfbrain increased progressively, it means the brain edema exists in the meantime. By comparison the unirradiation halfbrain, the apoptosis of the hippocampus cells in the irradiated brain increased, and the expression of bcl-2 protein decreased at the meantime, and those

  10. Experimental studies on pathogenesis of the brain radiation injury in early stage

    Energy Technology Data Exchange (ETDEWEB)

    Ye Tian [Suzhou Medical Coll., Jiangsu (China). 2nd Affiliated Hospital; Shiyao Bao; Weibo Yin; Chunfeng Liu; Zhilin Zhang

    2000-05-01

    To investigate the pathogenesis of the brain radiation injury in the early stage, a series of experiments were performed as below. The SD rats halfbrain were irradiated by the single dose of 10, 20, and 30 Gy of 4 MeV electron, all those experiments were performed in 1 day to 3 months after radiation. The neurological symptoms, the weight and the skin response inside the field of all the rats were evaluated sequentially. The measurement of regional cerebral blood flow (rCBF) using hydrogen gas generated by electrolysis, the calculation of the brain water content percentage with wet-dry weight formula. The DNA contents and the quantities of bcl-2 protein were analyzed by flow cytometry. The brain histological sections were scanned to assess the present or absence of white matter necrosis in the region of hippocampus, and then the hippocampus region was observed for the morphological changes of the blood vessel, neuroglial, and the neurons. Some of the data were analyzed by the Student t test. Intra-portal alopecia was observed in all rats which received 30 Gy and some rats which received 20 Gy, the abnormal neurological signs were not found in all the rats, but the tend of weight increase was less pronounced in 1-3 months in the irradiated rats than those unirradiated. By comparison the unirradiated hemisphere, the rCBF of the contralateral brain decreased in most of the rats. In 20 Gy and 30 Gy groups, rCBF decreased areas expand gradually along with the prolong of observation time, from the nucleus caudate putamen, to the frontal cortex and then the hippocampus, the rCBF of whole the irradiated hemibrain was reduced significantly at 3 month after radiation. The water content of the irradiated halfbrain increased progressively, it means the brain edema exists in the meantime. By comparison the unirradiation halfbrain, the apoptosis of the hippocampus cells in the irradiated brain increased, and the expression of bcl-2 protein decreased at the meantime, and those

  11. Histopathology as biomarkers: in treated mouse brain with radiation, cadmium and therapeutic agents (Aloe Vera)

    International Nuclear Information System (INIS)

    Chakrawarti, Aruna; Kanwar, Om; Nayak, Kamal Kumar; Ranga, Deepti

    2014-01-01

    There are two different types of radiation energetic particles and electromagnetic waves. These two types can penetrate into living tissue or cell and result in transduction of radiation energy to biological materials. The absorbed energy of ionising radiation can break chemical bonds and cause ionization of different molecules including water and different biological essential macromolecules of as DNA, membrane lipids and protein. Many types of DNA lesions are produce in cell by ionizing radiation and chemicals during cancer therapy. Cadmium is known to deplete glutathione and protein bounds sulfhydrl groups which results in enhance production of reactive oxygen species (ROS). The reactions of these ROS with cellular biomolecules have been shown to lead to lipid per-oxidation. Aloe vera is dietary antioxidant that plays an important role in controlling oxidative stress. For this purpose, six to eight weeks old male Swiss albino mice (Mus musculus) were randomly divided into seven groups. On the basis of radiation, cadmium, combined treatment and Aloe treated groups the animals were sacrificed at each post treatment intervals of 1, 2, 4, 7, 14 and 28 days. The brain were taken out and weighed to the analytical balance and fixed for 24 hours in alcoholic Bouin's fixative. A pinch of lithium carbonate was added to remove excess picric acid in the fixative. Histological studies were carried out using the standard techniques of haematoxyline and eosin staining. After combined treatment of radiation and cadmium chloride synergistic changes were observed. These changes were less severe in the Aloe vera treated brain which may be due to the protection provided by drug

  12. Rapid and simple method for quantitative evaluation of neurocytotoxic effects of radiation on developing medaka brain

    International Nuclear Information System (INIS)

    Yasuda, Takako; Maeda, Keiko; Matsumoto, Atsuko; Maruyama, Kouichi; Ishikawa, Yuji; Yoshimoto, Masami

    2008-01-01

    We describe a novel method for rapid and quantitative evaluation of the degree of radiation-induced apoptosis in the developing brain of medaka (Oryzias latipes). Embryos at stage 28 were irradiated with 1, 2, 3.5, and 5 Gy x-ray. Living embryos were stained with a vital dye, acridine orange (AO), for 1-2 h, and whole-mount brains were examined under an epifluorescence microscope. From 7 to 10 h after irradiation with 5 Gy x-ray, we found two morphologically different types of AO-stained structures, namely, small single nuclei and rosette-shaped nuclear clusters. Electron microscopy revealed that these two distinct types of structures were single apoptotic cells with condensed nuclei and aggregates of apoptotic cells, respectively. From 10 to 30 h after irradiation, a similar AO-staining pattern was observed. The numbers of AO-stained rosette-shaped nuclear clusters and AO-stained single nuclei increased in a dose-dependent manner in the optic tectum. We used the number of AO-stained rosette-shaped nuclear clusters/optic tectum as an index of the degree of radiation-induced brain cell death at 20-24 h after irradiation. The results showed that the number of rosette-shaped nuclear clusters/optic tectum in irradiated embryos exposed to 2 Gy or higher doses was highly significant compared to the number in nonirradiated control embryos, whereas no difference was detected at 1 Gy. Thus, the threshold dose for brain cell death in medaka embryos was taken as being between 1-2 Gy, which may not be so extraordinarily large compared to those for rodents and humans. The results show that medaka embryos are useful for quantitative evaluation of developmental neurocytotoxic effects of radiation. (author)

  13. Assessment of MRI Parameters as Imaging Biomarkers for Radiation Necrosis in the Rat Brain

    Energy Technology Data Exchange (ETDEWEB)

    Wang Silun [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Tryggestad, Erik [Department of Radiation Oncology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Zhou Tingting [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Armour, Michael [Department of Radiation Oncology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Wen Zhibo [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong (China); Fu Dexue [Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Ford, Eric [Department of Radiation Oncology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Zijl, Peter C.M. van [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland (United States); Zhou Jinyuan, E-mail: jzhou@mri.jhu.edu [Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD (United States); F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland (United States)

    2012-07-01

    Purpose: Radiation necrosis is a major complication of radiation therapy. We explore the features of radiation-induced brain necrosis in the rat, using multiple MRI approaches, including T{sub 1}, T{sub 2}, apparent diffusion constant (ADC), cerebral blood flow (CBF), magnetization transfer ratio (MTR), and amide proton transfer (APT) of endogenous mobile proteins and peptides. Methods and Materials: Adult rats (Fischer 344; n = 15) were irradiated with a single, well-collimated X-ray beam (40 Gy; 10 Multiplication-Sign 10 mm{sup 2}) in the left brain hemisphere. MRI was acquired on a 4.7-T animal scanner at {approx}25 weeks' postradiation. The MRI signals of necrotic cores and perinecrotic regions were assessed with a one-way analysis of variance. Histological evaluation was accomplished with hematoxylin and eosin staining. Results: ADC and CBF MRI could separate perinecrotic and contralateral normal brain tissue (p < 0.01 and < 0.05, respectively), whereas T{sub 1}, T{sub 2}, MTR, and APT could not. MRI signal intensities were significantly lower in the necrotic core than in normal brain for CBF (p < 0.001) and APT (p < 0.01) and insignificantly higher or lower for T{sub 1}, T{sub 2}, MTR, and ADC. Histological results demonstrated coagulative necrosis within the necrotic core and reactive astrogliosis and vascular damage within the perinecrotic region. Conclusion: ADC and CBF are promising imaging biomarkers for identifying perinecrotic regions, whereas CBF and APT are promising for identifying necrotic cores.

  14. Cost-effectiveness Analysis of Stereotactic Radiosurgery Alone Versus Stereotactic Radiosurgery with Upfront Whole Brain Radiation Therapy for Brain Metastases.

    Science.gov (United States)

    Kim, H; Rajagopalan, M S; Beriwal, S; Smith, K J

    2017-10-01

    Stereotactic radiosurgery (SRS) alone or upfront whole brain radiation therapy (WBRT) plus SRS are the most commonly used treatment options for one to three brain oligometastases. The most recent randomised clinical trial result comparing SRS alone with upfront WBRT plus SRS (NCCTG N0574) has favoured SRS alone for neurocognitive function, whereas treatment options remain controversial in terms of cognitive decline and local control. The aim of this study was to conduct a cost-effectiveness analysis of these two competing treatments. A Markov model was constructed for patients treated with SRS alone or SRS plus upfront WBRT based on largely randomised clinical trials. Costs were based on 2016 Medicare reimbursement. Strategies were compared using the incremental cost-effectiveness ratio (ICER) and effectiveness was measured in quality-adjusted life years (QALYs). One-way and probabilistic sensitivity analyses were carried out. Strategies were evaluated from the healthcare payer's perspective with a willingness-to-pay threshold of $100 000 per QALY gained. In the base case analysis, the median survival was 9 months for both arms. SRS alone resulted in an ICER of $9917 per QALY gained. In one-way sensitivity analyses, results were most sensitive to variation in cognitive decline rates for both groups and median survival rates, but the SRS alone remained cost-effective for most parameter ranges. Based on the current available evidence, SRS alone was found to be cost-effective for patients with one to three brain metastases compared with upfront WBRT plus SRS. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  15. Nasonia Parasitic Wasps Escape from Haller's Rule by Diphasic, Partially Isometric Brain-Body Size Scaling and Selective Neuropil Adaptations

    NARCIS (Netherlands)

    Groothuis, Jitte; Smid, Hans M.

    2017-01-01

    Haller's rule states that brains scale allometrically with body size in all animals, meaning that relative brain size increases with decreasing body size. This rule applies both on inter- and intraspecific comparisons. Only 1 species, the extremely small parasitic wasp Trichogramma evanescens, is

  16. Radiation inactivation analysis of assimilatory NADH:nitrate reductase. Apparent functional sizes of partial activities associated with intact and proteolytically modified enzyme

    International Nuclear Information System (INIS)

    Solomonson, L.P.; McCreery, M.J.; Kay, C.J.; Barber, M.J.

    1987-01-01

    Recently we demonstrated that target sizes for the partial activities of nitrate reductase were considerably smaller than the 100-kDa subunit which corresponded to the target size of the full (physiologic) activity NADH:nitrate reductase. These results suggested that the partial activities resided on functionally independent domains and that radiation inactivation may be due to localized rather than extensive damage to protein structure. The present study extends these observations and addresses several associated questions. Monophasic plots were observed over a wide range of radiation doses, suggesting a single activity component in each case. No apparent differences were observed over a 10-fold range of concentration for each substrate, suggesting that the observed slopes were not due to marked changes in Km values. Apparent target sizes estimated for partial activities associated with native enzyme and with limited proteolysis products of native enzyme suggested that the functional size obtained by radiation inactivation analysis is independent of the size of the polypeptide chain. The presence of free radical scavengers during irradiation reduced the apparent target size of both the physiologic and partial activities by an amount ranging from 24 to 43%, suggesting that a free radical mechanism is at least partially responsible for the inactivation. Immunoblot analysis of nitrate reductase irradiated in the presence of free radical scavengers revealed formation of distinct bands at 90, 75, and 40 kDa with increasing doses of irradiation rather than complete destruction of the polypeptide chain

  17. A GSK-3β Inhibitor Protects Against Radiation Necrosis in Mouse Brain

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Xiaoyu [Department of Chemistry, Washington University, St. Louis, Missouri (United States); Perez-Torres, Carlos J. [Department of Radiology, Washington University, St. Louis, Missouri (United States); Thotala, Dinesh [Department of Radiation Oncology, Washington University, St. Louis, Missouri (United States); Engelbach, John A. [Department of Radiology, Washington University, St. Louis, Missouri (United States); Yuan, Liya [Department of Neurosurgery, Washington University, St. Louis, Missouri (United States); Cates, Jeremy [Department of Radiation Oncology, Washington University, St. Louis, Missouri (United States); Gao, Feng [Division of Biostatistics, Washington University, St. Louis, Missouri (United States); Alvin J. Siteman Cancer Center, Washington University, St. Louis, Missouri (United States); Drzymala, Robert E.; Rich, Keith M. [Department of Radiation Oncology, Washington University, St. Louis, Missouri (United States); Department of Neurosurgery, Washington University, St. Louis, Missouri (United States); Schmidt, Robert E. [Department of Neuropathology, Washington University, St. Louis, Missouri (United States); Ackerman, Joseph J.H. [Department of Chemistry, Washington University, St. Louis, Missouri (United States); Department of Radiology, Washington University, St. Louis, Missouri (United States); Department of Internal Medicine, Washington University, St. Louis, Missouri (United States); Alvin J. Siteman Cancer Center, Washington University, St. Louis, Missouri (United States); Hallahan, Dennis E. [Department of Radiation Oncology, Washington University, St. Louis, Missouri (United States); Alvin J. Siteman Cancer Center, Washington University, St. Louis, Missouri (United States); Garbow, Joel R., E-mail: garbow@wustl.edu [Department of Radiology, Washington University, St. Louis, Missouri (United States); Alvin J. Siteman Cancer Center, Washington University, St. Louis, Missouri (United States)

    2014-07-15

    Purpose: To quantify the effectiveness of SB415286, a specific inhibitor of GSK-3β, as a neuroprotectant against radiation-induced central nervous system (brain) necrosis in a mouse model. Methods and Materials: Cohorts of mice were treated with SB415286 or dimethyl sulfoxide (DMSO) prior to irradiation with a single 45-Gy fraction targeted to the left hemisphere (brain) using a gamma knife machine. The onset and progression of radiation necrosis (RN) were monitored longitudinally by noninvasive in vivo small-animal magnetic resonance imaging (MRI) beginning 13 weeks postirradiation. MRI-derived necrotic volumes for SB415286- and DMSO-treated mice were compared. MRI results were supported by correlative histology. Results: Mice treated with SB415286 showed significant protection from radiation-induced necrosis, as determined by in vivo MRI with histologic validation. MRI-derived necrotic volumes were significantly smaller at all postirradiation time points in SB415286-treated animals. Although the irradiated hemispheres of the DMSO-treated mice demonstrated many of the classic histologic features of RN, including fibrinoid vascular necrosis, vascular telangiectasia, hemorrhage, and tissue loss, the irradiated hemispheres of the SB415286-treated mice consistently showed only minimal tissue damage. These studies confirmed that treatment with a GSK-3β inhibitor dramatically reduced delayed time-to-onset necrosis in irradiated brain. Conclusions: The unilateral cerebral hemispheric stereotactic radiation surgery mouse model in concert with longitudinal MRI monitoring provided a powerful platform for studying the onset and progression of RN and for developing and testing new neuroprotectants. Effectiveness of SB415286 as a neuroprotectant against necrosis motivates potential clinical trials of it or other GSK-3β inhibitors.

  18. A GSK-3β Inhibitor Protects Against Radiation Necrosis in Mouse Brain

    International Nuclear Information System (INIS)

    Jiang, Xiaoyu; Perez-Torres, Carlos J.; Thotala, Dinesh; Engelbach, John A.; Yuan, Liya; Cates, Jeremy; Gao, Feng; Drzymala, Robert E.; Rich, Keith M.; Schmidt, Robert E.; Ackerman, Joseph J.H.; Hallahan, Dennis E.; Garbow, Joel R.

    2014-01-01

    Purpose: To quantify the effectiveness of SB415286, a specific inhibitor of GSK-3β, as a neuroprotectant against radiation-induced central nervous system (brain) necrosis in a mouse model. Methods and Materials: Cohorts of mice were treated with SB415286 or dimethyl sulfoxide (DMSO) prior to irradiation with a single 45-Gy fraction targeted to the left hemisphere (brain) using a gamma knife machine. The onset and progression of radiation necrosis (RN) were monitored longitudinally by noninvasive in vivo small-animal magnetic resonance imaging (MRI) beginning 13 weeks postirradiation. MRI-derived necrotic volumes for SB415286- and DMSO-treated mice were compared. MRI results were supported by correlative histology. Results: Mice treated with SB415286 showed significant protection from radiation-induced necrosis, as determined by in vivo MRI with histologic validation. MRI-derived necrotic volumes were significantly smaller at all postirradiation time points in SB415286-treated animals. Although the irradiated hemispheres of the DMSO-treated mice demonstrated many of the classic histologic features of RN, including fibrinoid vascular necrosis, vascular telangiectasia, hemorrhage, and tissue loss, the irradiated hemispheres of the SB415286-treated mice consistently showed only minimal tissue damage. These studies confirmed that treatment with a GSK-3β inhibitor dramatically reduced delayed time-to-onset necrosis in irradiated brain. Conclusions: The unilateral cerebral hemispheric stereotactic radiation surgery mouse model in concert with longitudinal MRI monitoring provided a powerful platform for studying the onset and progression of RN and for developing and testing new neuroprotectants. Effectiveness of SB415286 as a neuroprotectant against necrosis motivates potential clinical trials of it or other GSK-3β inhibitors

  19. On Effective Radiative Forcing of Partial Internally and Externally Mixed Aerosols and Their Effects on Global Climate

    Science.gov (United States)

    Zhou, Chen; Zhang, Hua; Zhao, Shuyun; Li, Jiangnan

    2018-01-01

    The total effective radiative forcing (ERF) due to partial internally mixed (PIM) and externally mixed (EM) anthropogenic aerosols, as well as their climatic effects since the year of 1850, was evaluated and compared using the aerosol-climate online coupled model of BCC_AGCM2.0_CUACE/Aero. The influences of internal mixing (IM) on aerosol hygroscopicity parameter, optical properties, and concentration were considered. Generally, IM could markedly weaken the negative ERF and cooling effects of anthropogenic aerosols. The global annual mean ERF of EM anthropogenic aerosols from 1850 to 2010 was -1.87 W m-2, of which the aerosol-radiation interactive ERF (ERFari) and aerosol-cloud interactive ERF (ERFaci) were -0.49 and -1.38 W m-2, respectively. The global annual mean ERF due to PIM anthropogenic aerosols from 1850 to 2010 was -1.23 W m-2, with ERFari and ERFaci of -0.23 and -1.01 W m-2, respectively. The global annual mean surface temperature and water evaporation and precipitation were reduced by 1.74 K and 0.14 mm d-1 for EM scheme and 1.28 K and 0.11 mm d-1 for PIM scheme, respectively. However, the relative humidity near the surface was slightly increased for both mixing cases. The Intertropical Convergence Zone was southwardly shifted for both EM and PIM cases but was less southwardly shifted in PIM scheme due to the less reduction in atmospheric temperature in the midlatitude and low latitude of the Northern Hemisphere.

  20. Characterization of the pharmacokinetics, brain distribution, and therapeutic efficacy of the adenosine A1 receptor partial agonist 2'-deoxy-N6-cyclopentyladenosine in sarin-poisoned rats

    International Nuclear Information System (INIS)

    Bueters, Tjerk J.H.; IJzerman, Ad P.; Helden, Herman P.M. van; Danhof, Meindert

    2003-01-01

    Characterization of the pharmacokinetics, brain distribution, and therapeutic efficacy of the adenosine A 1 receptor partial agonist 2'-deoxy-N 6 -cyclopentyladenosine in sarin-poisoned rats. Bueters, T.J.H., IJzerman, A.P., Van Helden, H.P.M., and Danhof, M. (2003). The objective of the present study was to determine (1) the influence of sarin poisoning (144 μg/kg sc) on the pharmacokinetics and brain distribution of the adenosine A 1 receptor partial agonist 2'-deoxy-N 6 -cyclopentyladenosine (2'dCPA), and (2) the effect of 2'dCPA (20 mg/kg iv) on the central acetylcholine (ACh) release and protection against sarin toxicity. A five-compartment model successfully described the pharmacokinetic profile of 2'dCPA in blood and brain microdialysate. A covariate analysis revealed that the volume of distribution of 2'dCPA in blood was different in sarin-poisoned rats, 177 ± 7 versus 148 ± 8 ml in control rats. However, the transport of 2'dCPA from blood to the brain was unaffected as reflected by the values of the intercompartmental transport clearances, 0.21 ± 0.02 and 0.21 ± 0.04 μl/min in control and sarin-poisoned rats, respectively. Also the area-under-curve (AUC) ratios of brain microdialysate and blood were identical with values of 0.02 ± 0.001 and 0.02 ± 0.002, respectively, demonstrating the restricted transport of 2'dCPA into the brain in both treatment groups. Treatment of sarin-poisoned rats by 2'dCPA did not adequately prevent the accumulation of ACh in the central nervous system. 2'dCPA delayed the emergence of concomitant symptoms compared to untreated rats, but eventually only 29% of the animals survived 24 h. In conclusion, the pharmacokinetic profile of 2'dCPA in blood was slightly changed by sarin, but not the distribution of 2'dCPA into the brain. The therapeutic efficacy of 2'dCPA against sarin was limited, presumably due to insufficient quantities of 2'dCPA reaching the brain

  1. Late radiation effects on hearing, vestibular function, and taste in brain tumor patients

    International Nuclear Information System (INIS)

    Johannesen, Tom B.; Rasmussen, Kjell; Winther, Finn Oe.; Halvorsen, Ulf; Lote, Knut

    2002-01-01

    Purpose: To investigate late radiation effects on hearing, vestibular function, and taste after conventional radiotherapy in brain tumor patients. Methods and Materials: Hearing, vestibular function, and taste were assessed in 33 brain tumor patients irradiated unilaterally to the tumor-bearing hemisphere and the temporal bone. Median observation time after completion of radiotherapy was 13 years; the fraction dose was 1.8 Gy, and mean radiation dose was 53.1 Gy. Results: Deep ulceration in the external ear canal and osteoradionecrosis on the irradiated side was seen in three patients. Reduced hearing was found for air and bone conduction of the irradiated side compared to the opposite side (0.25-2 kHz: 6.1 dB, 4 kHz: 10.3 dB, 6 kHz: 15.6 dB, and 8 kHz: 16.5 dB). For bone conduction, the corresponding figures were 0.25-2 kHz: 5.5 dB and 4 kHz: 8.2 dB. Three patients had a canal paresis of the irradiated side, and three patients had affection of the chorda tympani. Conclusion: Irradiation of the temporal bone with doses usually given in the treatment of patients with brain tumors may cause osteoradionecrosis, sensorineural hearing loss, dysfunction of the vestibular inner ear, and loss of taste. Head-and-neck examination should be included in the follow-up of long-term survivors

  2. Low intensity microwave radiation induced oxidative stress, inflammatory response and DNA damage in rat brain.

    Science.gov (United States)

    Megha, Kanu; Deshmukh, Pravin Suryakantrao; Banerjee, Basu Dev; Tripathi, Ashok Kumar; Ahmed, Rafat; Abegaonkar, Mahesh Pandurang

    2015-12-01

    Over the past decade people have been constantly exposed to microwave radiation mainly from wireless communication devices used in day to day life. Therefore, the concerns over potential adverse effects of microwave radiation on human health are increasing. Until now no study has been proposed to investigate the underlying causes of genotoxic effects induced by low intensity microwave exposure. Thus, the present study was undertaken to determine the influence of low intensity microwave radiation on oxidative stress, inflammatory response and DNA damage in rat brain. The study was carried out on 24 male Fischer 344 rats, randomly divided into four groups (n=6 in each group): group I consisted of sham exposed (control) rats, group II-IV consisted of rats exposed to microwave radiation at frequencies 900, 1800 and 2450 MHz, specific absorption rates (SARs) 0.59, 0.58 and 0.66 mW/kg, respectively in gigahertz transverse electromagnetic (GTEM) cell for 60 days (2h/day, 5 days/week). Rats were sacrificed and decapitated to isolate hippocampus at the end of the exposure duration. Low intensity microwave exposure resulted in a frequency dependent significant increase in oxidative stress markers viz. malondialdehyde (MDA), protein carbonyl (PCO) and catalase (CAT) in microwave exposed groups in comparison to sham exposed group (pmicrowave exposed groups (pmicrowave exposed animal (pmicrowave exposed groups as compared to their corresponding values in sham exposed group (pmicrowave radiation induces oxidative stress, inflammatory response and DNA damage in brain by exerting a frequency dependent effect. The study also indicates that increased oxidative stress and inflammatory response might be the factors involved in DNA damage following low intensity microwave exposure. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Brain signaling and behavioral responses induced by exposure to (56)Fe-particle radiation

    Science.gov (United States)

    Denisova, N. A.; Shukitt-Hale, B.; Rabin, B. M.; Joseph, J. A.

    2002-01-01

    Previous experiments have demonstrated that exposure to 56Fe-particle irradiation (1.5 Gy, 1 GeV) produced aging-like accelerations in neuronal and behavioral deficits. Astronauts on long-term space flights will be exposed to similar heavy-particle radiations that might have similar deleterious effects on neuronal signaling and cognitive behavior. Therefore, the present study evaluated whether radiation-induced spatial learning and memory behavioral deficits are associated with region-specific brain signaling deficits by measuring signaling molecules previously found to be essential for behavior [pre-synaptic vesicle proteins, synaptobrevin and synaptophysin, and protein kinases, calcium-dependent PRKCs (also known as PKCs) and PRKA (PRKA RIIbeta)]. The results demonstrated a significant radiation-induced increase in reference memory errors. The increases in reference memory errors were significantly negatively correlated with striatal synaptobrevin and frontal cortical synaptophysin expression. Both synaptophysin and synaptobrevin are synaptic vesicle proteins that are important in cognition. Striatal PRKA, a memory signaling molecule, was also significantly negatively correlated with reference memory errors. Overall, our findings suggest that radiation-induced pre-synaptic facilitation may contribute to some previously reported radiation-induced decrease in striatal dopamine release and for the disruption of the central dopaminergic system integrity and dopamine-mediated behavior.

  4. Effects of lanthanum exposure on elemental distribution in rat brains measured by synchrotron radiation XRF

    International Nuclear Information System (INIS)

    Feng Liuxing; Xiao Haiqing; He Xiao; Liu Nianqing; Zhao Yuliang; Chai Zhifang; Zhang Zhiyong

    2005-01-01

    Rare earth elements (REEs) comprise a coherent series of 15 elements from lanthanum to lutetium and possessing very similar chemical properties. In recent decades, with the rapid increase of the exploitation of REE resources and their applications to modern industry and daily life, particularly to agriculture as fertilizer additives in China, more and more REEs are coming into environmental system as well as food chain through various ways. It has become increasingly important to obtain more information on the physiological function of REEs and their long-term biological effects on body of living beings. Epidemiological investigations found that the intelligence quotients (IQ) of children from the REE-high background regions are obviously different from that of the normal region. This indicated that REEs probably affect the function of brain. However, the mechanism is totally unknown. The contents and distributions of major and trace elements are sometimes good indicators of the physiological and pathological conditions of human and animal brains In this study, the effects of subchronic lanthanum exposure on the elemental distribution in the rat brains were studied. Wistar rats were exposed to lanthanum chloride through oral administration at O, 0.1, 2, and 40-mg/kg doses for 6 months. The elements such as Cl, K, Ca, Fe, Cu, and Zn in brain slices were identified by synchrotron radiation X-ray fluorescence analysis. Differences in two-dimensional maps of elemental distribution were noticed. Cl, Ca, and Zn were primarily concentrated in hippocampus of the controls. With the increase of the lanthanum dosage, the Ca and Zn levels were significantly decreased, while the Cu levels were significantly elevated in cortex, hippocampus and thalamus. Our results suggest that subchronic lanthanum exposure in rats appears to change elemental distribution in brain. The impact of lanthanides on brain function is not negligible.

  5. Comparison of the effects of radiation and hyperthermia on prenatal retardation of brain growth of guinea-pigs

    International Nuclear Information System (INIS)

    Wanner, R.A.; Edwards, M.J.

    1983-01-01

    On day 21 of pregnancy guinea-pigs were exposed to hyperthermia or #betta# radiation. The effects on prenatal growth and especially brain growth of offspring were compared. Doses of 0.04-0.99 Gy of radiation produced a dose-dependent and irreversible reduction of brainweight in the offspring, but had little effect on body weight. Treatment with hyperthermia resulting in maternal temperatures of 41.8-43.9 0 C after exposure in a heated incubator for an hour also produced a dose-related micrencephaly in the offspring. Comparison of the two agents showed that a dose increment of 0.525 Gy of radiation produced a deficit in brain weight equivalent to an elevation of 1 0 C in maternal temperature. Using this guinea-pig brain weight assay system a threshold was detected of between 0.05 and 0.10 Gy for retardation of brain growth. (author)

  6. Synthesis and degradation of cyclic nucleotides in brain after a high dose of ionizing radiation

    International Nuclear Information System (INIS)

    Hunt, W.A.; Dalton, T.K.

    1981-01-01

    Previous data from our laboratory have indicated that a high dose of ionizing radiation can deplete the cyclic nucleotides guanosine 3',5'-cyclic monophosphate (cGMP) and adenosine 3',5'-cyclic monophosphate (cAMP) on several areas of the rat brain. cGMP is more sensitive to radiation than cAMP and does not recover for at least 24 h after irradiation. The response of cAMP is transient and recovery occurs within 4 h. The purpose of the present paper is to determine whether alternations in the activity of the synthetic and degradative enzymes that regulate cyclic nucleotide levels could account for the observed effects. Guanylate and adenylate cyclase and cGMP and cAMP phosphodiesterase activities were determined 10 min after irradiation with 10,000 rad of high-energy electrons. No alteration was detected under these experimental conditions. The data suggest that the reduction in cyclic nucleotides is not a direct effect on their metabolic enzymes and is probably secondary to some as yet-undefined action of radiation on the brain

  7. A novel schedule of accelerated partial breast radiation using intensity-modulated radiation therapy in elderly patients: survival and toxicity analysis of a prospective clinical trial

    Energy Technology Data Exchange (ETDEWEB)

    Sayan, Mutlay; Nelson, Carl; Gagne, Havaleh; Rubin, Deborah; Heimann, Ruth [Dept. of Radiation Oncology, University of Vermont Medical Center, Burlington (United States); Wilson, Karen [University of Vermont Cancer Center, Burlington (United States)

    2017-03-15

    Several accelerated partial breast radiation (APBR) techniques have been investigated in patients with early-stage breast cancer (BC); however, the optimal treatment delivery techniques remain unclear. We evaluated the feasibility and toxicity of APBR delivered using intensity-modulated radiation therapy (IMRT) in elderly patients with stage I BC, using a novel fractionation schedule. Forty-two patients aged ≥65 years, with stage I BC who underwent breast conserving surgery were enrolled in a phase I/II study evaluating APBR using IMRT. Forty eligible patients received 40 Gy in 4 Gy daily fractions. Patients were assessed for treatment related toxicities, and cosmesis, before APBR, during, and after completion of the treatment. The median age was 73 years, median tumor size 0.8 cm and the median follow-up was 54 months. The 5-year locoregional control was 97.5% and overall survival 90%. Erythema and skin pigmentation was the most common acute adverse event, reported by 27 patients (69%). Twenty-six patients (65%) reported mild pain, rated 1-4/10. This improved at last follow-up to only 2 (15%). Overall the patient and physician reported worst late toxicities were lower than the baseline and at last follow-up, patients and physicians rated cosmesis as excellent/good in 93% and 86 %, respectively. In this prospective trial, we observed an excellent rate of tumor control with daily APBR. The acceptable toxicity profile and cosmetic results of this study support the use of IMRT planned APBR with daily schedule in elderly patients with early stage BC.

  8. Measurement of radiation dose to the eye-lens with bilateral whole brain irradiation

    International Nuclear Information System (INIS)

    Kim, Ki Hwan; Park, Charn Il; Kang, Wee Saing; Choo, Dong Woon

    1985-01-01

    In 40 patients with metastatic brain tumor and acute lymphoblastic leukemia received whole brain irradiation, the dose delivered to the eye lens was measured using T.L.D. chips applied on the eyes as usual shield. The dose to the eye lens was expressed the relative dose to the mid brain dose. Radiotherapy was administrated using Co-60 teletherapy with bilateral whole brain irradiation. The results are as follows: 1. The dose to the right eye from its incipient field is 16.6% of tumor dose while the dose to the same eye from the opposite field is 41.2%. On left eye, 19.2% from incipient field while 39.2% from the opposite field. 2. Total received dose to right and left eyes is 28.9%, 29.8% of tumor dose respectively. 3. Comparing lens shield group with orbit shield group dose is 22.5%, 15.8% of tumor dose, respectively. 4. The dose delivered to the eye lens in ipsilateral side depends upon internal scattering, location of lead shield and penetrating dose of lead in itself. The dose in contralateral side depends upon divergency of radiation beam and patient's malposition. 5. The dose to the eye lens should be less than 10% of tumor dose with adequate shield, also not missing the chance of leptomeningeal recurrence because of overshielding.

  9. Is whole brain radiation therapy needed for all patients with newly diagnosed brain metastases undergoing stereotactic radiosurgery?

    International Nuclear Information System (INIS)

    Suh, John H.; Barnett, Gene H.; Miller, David W.; Kupelian, Patrick A.; Cohen, Bruce H.

    1997-01-01

    PURPOSE: Since whole brain radiation therapy (WBRT) carries risks for long term survivors of brain metastases, some have advocated the use of stereotactic radiosurgery (SRS) alone for patients with brain metastases. We retrospectively reviewed our results of stereotactic radiosurgery (SRS) with immediate or delayed WBRT. MATERIALS/METHODS: From March 1990 to December 1996, linear accelerator-based SRS was performed on patients with Karnofsky score ≥ 70 and asymptomatic or mildly symptomatic brain metastases < 4 cm diameter. After excluding those patients with recurrent disease, 87 patients with 106 metastatic lesions (72 pts- single or solitary lesion, 13 pts- 2 lesions, 1 pt- 3 lesions, and 1 pt- 5 lesions) remained for analysis. The use of WBRT was dependent on physician preference but was given to all patients who developed local or regional failure after SRS. Survival was measured from the date of SRS until death or last follow-up using Kaplan-Meier method. Freedom from progression (FFP) was defined as no local or regional brain failure on follow-up radiographs and was measured from the date of SRS. RESULTS: Prognostic variables (age, sex, initial KPS, systemic disease, and extent of surgical resection) were similar for the 40 patients in the immediate WBRT group (iWBRT) and for the 47 patients in the delayed WBRT group (dWBRT). With a median follow-up of 5.8 months, no significant difference in median survival (6.9 months for both groups) was noted. On multivariate analysis, absence of systemic disease (p=0.008) and KPS 90-100 (p=0.001) were the only significant predictors for survival. For the 29 patients with a minimum KPS of 90 and no systemic disease, the median survival was 17.8 months. For those patients with a solitary lesion (no systemic disease), there was a trend for better median survival for the iWBRT group (22.8 months) versus the dWBRT group (9.3 months), p=0.06. FFP data was available on 78 patients (97 lesions). A significant difference was

  10. Radiation-induced changes in human brain metabolites as studied by {sup 1}H nuclear magnetic resonance spectroscopy in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Usenius, Taina; Usenius, Jussi-Pekka; Tenhunen, Mikko; Vainio, Pauli; Johansson, Risto; Soimakallio, Seppo; Kauppinen, Risto

    1995-10-15

    Purpose: External radiation therapy for brain tumors exposes healthy areas of brain to considerable doses of radiation. This may cause cognitive and psychological impairment, which indicate neuronal dysfunction. {sup 1}H-magnetic resonance spectroscopy (MRS) was used to study brain metabolites in the adjacent regions 0.5-13 years after exposure to therapeutic irradiation. Methods and Materials: Eight patients with irradiated brain tumors were examined by means of in vivo{sup 1}H-MRS using a point-resolved spectroscopy (PRESS) sequence with echo times of 60 or 270 ms. The metabolites were quantified by using brain water concentration as internal reference. The volume of interest (VOI) was positioned in irradiated brain areas excluding, however, scar and recurrent tumor. The respective radiation doses were measured based on radiation therapy plans, simulator films, and localization MR images. Results: The concentration of the neuron-specific metabolite N-acetyl-l-aspartate (NAA) was 13.2 {+-} 1.4 mmol/l in controls, whereas it was reduced in the brains of treated patients to 8.6 {+-} 0.9 mmol/l (total radiation dose 59-62 Gy). Concentrations of creatine and choline-containing compounds were unchanged. The T2 of water was longer in irradiated than in unexposed brain areas. Conclusion: Therapeutic brain irradiation causes neuronal damage, which is reflected by reduction of N-acetyl-l-aspartate (NAA) concentrations. {sup 1}H-MRS could serve clinically as a means of evaluating adverse effects in the central nervous system, enabling intervention and rehabilitation.

  11. Radiation-induced changes in human brain metabolites as studied by 1H nuclear magnetic resonance spectroscopy in vivo

    International Nuclear Information System (INIS)

    Usenius, Taina; Usenius, Jussi-Pekka; Tenhunen, Mikko; Vainio, Pauli; Johansson, Risto; Soimakallio, Seppo; Kauppinen, Risto

    1995-01-01

    Purpose: External radiation therapy for brain tumors exposes healthy areas of brain to considerable doses of radiation. This may cause cognitive and psychological impairment, which indicate neuronal dysfunction. 1 H-magnetic resonance spectroscopy (MRS) was used to study brain metabolites in the adjacent regions 0.5-13 years after exposure to therapeutic irradiation. Methods and Materials: Eight patients with irradiated brain tumors were examined by means of in vivo 1 H-MRS using a point-resolved spectroscopy (PRESS) sequence with echo times of 60 or 270 ms. The metabolites were quantified by using brain water concentration as internal reference. The volume of interest (VOI) was positioned in irradiated brain areas excluding, however, scar and recurrent tumor. The respective radiation doses were measured based on radiation therapy plans, simulator films, and localization MR images. Results: The concentration of the neuron-specific metabolite N-acetyl-l-aspartate (NAA) was 13.2 ± 1.4 mmol/l in controls, whereas it was reduced in the brains of treated patients to 8.6 ± 0.9 mmol/l (total radiation dose 59-62 Gy). Concentrations of creatine and choline-containing compounds were unchanged. The T2 of water was longer in irradiated than in unexposed brain areas. Conclusion: Therapeutic brain irradiation causes neuronal damage, which is reflected by reduction of N-acetyl-l-aspartate (NAA) concentrations. 1 H-MRS could serve clinically as a means of evaluating adverse effects in the central nervous system, enabling intervention and rehabilitation

  12. Effects of low doses of gamma radiation on DNA synthesis in the developing rat brain

    International Nuclear Information System (INIS)

    Cerda, H.

    1983-01-01

    Rats of one or ten days of age were irradiated with low doses of gamma radiation, and synthesis of DNA was examined by the incorporation of 3 H-thymidine in the cerebellum and the rest of the brain in vivo. DNA synthesis was depressed in both parts of the brain but the effects were larger in cerebellum. A minimum was found about 10 hours after irradiation in the older rats and later (18 h) in the younger ones. The dose response in 10 day-old rats, was biphasic and showed that cerebellum was more affected. Autoradiographs showed that fewer cells entered the cycle and those synthesizing showed a depressed rate of synthesis. These findings are discussed in relation to induction of cell death. (Auth.)

  13. The long-term side effects of radiation therapy for benign brain tumors in adults

    International Nuclear Information System (INIS)

    al-Mefty, O.; Kersh, J.E.; Routh, A.; Smith, R.R.

    1990-01-01

    Radiation therapy plays an integral part in managing intracranial tumors. While the risk:benefit ratio is considered acceptable for treating malignant tumors, risks of long-term complications of radiotherapy need thorough assessment in adults treated for benign tumors. Many previously reported delayed complications of radiotherapy can be attributed to inappropriate treatment or to the sensitivity of a developing child's brain to radiation. Medical records, radiological studies, autopsy findings, and follow-up information were reviewed for 58 adult patients (31 men and 27 women) treated between 1958 and 1987 with radiotherapy for benign intracranial tumors. Patient ages at the time of irradiation ranged from 21 to 87 years (mean 47.7 years). The pathology included 46 pituitary adenomas, five meningiomas, four glomus jugulare tumors, two pineal area tumors, and one craniopharyngioma. Average radiation dosage was 4984 cGy (range 3100 to 7012 cGy), given in an average of 27.2 fractions (range 15 to 45 fractions), over a period averaging 46.6 days. The follow-up period ranged from 3 to 31 years (mean 8.1 years). Findings related to tumor recurrence or surgery were excluded. Twenty-two patients had complications considered to be delayed side effects of radiotherapy. Two patients had visual deterioration developing 3 and 6 years after treatment; six had pituitary dysfunction; and 17 had varying degrees of parenchymal changes of the brain, occurring mostly in the temporal lobes and relating to the frequent presentation of pituitary tumors. One clival tumor with the radiographic appearance of a meningioma, developed 30 years post-irradiation for acromegaly. This study unveils considerable delayed sequelae of radiotherapy in a series of adult patients receiving what is considered safe treatment for benign brain tumors. 163 refs

  14. The long-term side effects of radiation therapy for benign brain tumors in adults

    Energy Technology Data Exchange (ETDEWEB)

    al-Mefty, O.; Kersh, J.E.; Routh, A.; Smith, R.R. (Univ. of Mississippi Medical Center, Jackson (USA))

    1990-10-01

    Radiation therapy plays an integral part in managing intracranial tumors. While the risk:benefit ratio is considered acceptable for treating malignant tumors, risks of long-term complications of radiotherapy need thorough assessment in adults treated for benign tumors. Many previously reported delayed complications of radiotherapy can be attributed to inappropriate treatment or to the sensitivity of a developing child's brain to radiation. Medical records, radiological studies, autopsy findings, and follow-up information were reviewed for 58 adult patients (31 men and 27 women) treated between 1958 and 1987 with radiotherapy for benign intracranial tumors. Patient ages at the time of irradiation ranged from 21 to 87 years (mean 47.7 years). The pathology included 46 pituitary adenomas, five meningiomas, four glomus jugulare tumors, two pineal area tumors, and one craniopharyngioma. Average radiation dosage was 4984 cGy (range 3100 to 7012 cGy), given in an average of 27.2 fractions (range 15 to 45 fractions), over a period averaging 46.6 days. The follow-up period ranged from 3 to 31 years (mean 8.1 years). Findings related to tumor recurrence or surgery were excluded. Twenty-two patients had complications considered to be delayed side effects of radiotherapy. Two patients had visual deterioration developing 3 and 6 years after treatment; six had pituitary dysfunction; and 17 had varying degrees of parenchymal changes of the brain, occurring mostly in the temporal lobes and relating to the frequent presentation of pituitary tumors. One clival tumor with the radiographic appearance of a meningioma, developed 30 years post-irradiation for acromegaly. This study unveils considerable delayed sequelae of radiotherapy in a series of adult patients receiving what is considered safe treatment for benign brain tumors. 163 refs.

  15. Radiation-induced late brain injury and the protective effect of traditional Chinese medicine

    International Nuclear Information System (INIS)

    Yi Junlin; Miao Yanjun; Yang Weizhi; Cai Weiming; Liu Yajie

    2004-01-01

    Objective: To investigate whether radiation-induced late injury of the brain can be ameliorated by traditional Chinese Medicine through blocking the primary events. Methods: This trial included five animal groups: sham irradiation, irradiation only, and three treatment groups. The whole brain of BALB/C mouse was irradiated with 22 Gy by using a 6 MV linear accelerator. Step down method was used to evaluate the study and memory abilities. Mouse weight was also recorded every week before and after irradiation. On D90, all mice alive were euthanized and Glee's silver dye method and Bielschousky silver dye method were used to detect the senile plaque and the neurofibrillary tangle. One-Way ANOVA was used to evaluate the differences among the groups in the various aspects of study and memory abilities as well as quality of life. Kaplan-Meier was used to evaluate the survival. Log-rank was used to detect the differences among the survival groups. Results: 1. There was no significant difference in survival among the treatment groups, even though Salvia Miltiorrhiza (SM) was able to improve the quality of life. As to the cognition function, it was shown that whole brain radiation would make a severe cognition damage with the learning and memorizing ability of the irradiated mice being worse than those of the sham irradiation group. The Traditional Chinese Medicine Salvia Miltiorrhiza possesses the role of a protective agent against cognition function damage induced by irradiation. 2. Glee's silver dye and Bielschousky silver dye show much more senile plaque and the neurofibrillary tangle in brain tissue of R group and R + 654-2 group than those in the R + SM group. Conclusions: Salvia Miltiorrhiza is able to protect the mouse from cognition function damage induced by irradiation and improve the quality of life by ameliorating the primary events, though it does not improve the survival

  16. Brain Metastasis Velocity: A Novel Prognostic Metric Predictive of Overall Survival and Freedom From Whole-Brain Radiation Therapy After Distant Brain Failure Following Upfront Radiosurgery Alone

    Energy Technology Data Exchange (ETDEWEB)

    Farris, Michael, E-mail: mfarris@wakehealth.edu [Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, North Carolina (United States); McTyre, Emory R.; Cramer, Christina K.; Hughes, Ryan; Randolph, David M.; Ayala-Peacock, Diandra N.; Bourland, J. Daniel [Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, North Carolina (United States); Ruiz, Jimmy [Department of Medicine - Hematology & Oncology, Wake Forest School of Medicine, Winston-Salem, North Carolina (United States); Watabe, Kounosuke [Department of Cancer Biology, Wake Forest School of Medicine, Winston-Salem, North Carolina (United States); Laxton, Adrian W.; Tatter, Stephen B. [Department of Neurosurgery, Wake Forest School of Medicine, Winston-Salem, North Carolina (United States); Zhou, Xiaobo [Center for Bioinformatics & Systems Biology, Wake Forest School of Medicine, Winston-Salem, North Carolina (United States); Chan, Michael D. [Department of Radiation Oncology, Wake Forest School of Medicine, Winston-Salem, North Carolina (United States)

    2017-05-01

    Purpose: Prior statistical models attempted to identify risk factors for time to distant brain failure (DBF) or time to salvage whole-brain radiation therapy (WBRT) to predict the benefit of early WBRT versus stereotactic radiosurgery (SRS) alone. We introduce a novel clinical metric, brain metastasis velocity (BMV), for predicting clinical outcomes after initial DBF following upfront SRS alone. Methods and Materials: BMV was defined as the cumulative number of new brain metastases that developed over time since first SRS in years. Patients were classified by BMV into low-, intermediate-, and high-risk groups, consisting of <4, 4 to 13, and >13 new metastases per year, respectively. Histology, number of metastases at the time of first SRS, and systemic disease status were assessed for effect on BMV. Results: Of 737 patients treated at our institution with upfront SRS without WBRT, 286 had ≥1 DBF event. A lower BMV predicted for improved overall survival (OS) following initial DBF (log-rank P<.0001). Median OS for the low, intermediate, and high BMV groups was 12.4 months (95% confidence interval [CI], 10.4-16.9 months), 8.2 months (95% CI, 5.0-9.7 months), and 4.3 months (95% CI, 2.6-6.7 months), respectively. Multivariate analysis showed that BMV remained the dominant predictor of OS, with a hazard ratio of 2.75 for the high BMV group (95% CI, 1.94-3.89; P<.0001) and a hazard ratio of 1.65 for the intermediate BMV group (95% CI, 1.18-2.30; P<.004). A lower BMV was associated with decreased rates of salvage WBRT (P=.02) and neurologic death (P=.008). Factors predictive for a higher BMV included ≥2 initial brain metastases (P=.004) and melanoma histology (P=.008). Conclusions: BMV is a novel metric associated with OS, neurologic death, and need for salvage WBRT after initial DBF following upfront SRS alone.

  17. Brain Metastasis Velocity: A Novel Prognostic Metric Predictive of Overall Survival and Freedom From Whole-Brain Radiation Therapy After Distant Brain Failure Following Upfront Radiosurgery Alone

    International Nuclear Information System (INIS)

    Farris, Michael; McTyre, Emory R.; Cramer, Christina K.; Hughes, Ryan; Randolph, David M.; Ayala-Peacock, Diandra N.; Bourland, J. Daniel; Ruiz, Jimmy; Watabe, Kounosuke; Laxton, Adrian W.; Tatter, Stephen B.; Zhou, Xiaobo; Chan, Michael D.

    2017-01-01

    Purpose: Prior statistical models attempted to identify risk factors for time to distant brain failure (DBF) or time to salvage whole-brain radiation therapy (WBRT) to predict the benefit of early WBRT versus stereotactic radiosurgery (SRS) alone. We introduce a novel clinical metric, brain metastasis velocity (BMV), for predicting clinical outcomes after initial DBF following upfront SRS alone. Methods and Materials: BMV was defined as the cumulative number of new brain metastases that developed over time since first SRS in years. Patients were classified by BMV into low-, intermediate-, and high-risk groups, consisting of <4, 4 to 13, and >13 new metastases per year, respectively. Histology, number of metastases at the time of first SRS, and systemic disease status were assessed for effect on BMV. Results: Of 737 patients treated at our institution with upfront SRS without WBRT, 286 had ≥1 DBF event. A lower BMV predicted for improved overall survival (OS) following initial DBF (log-rank P<.0001). Median OS for the low, intermediate, and high BMV groups was 12.4 months (95% confidence interval [CI], 10.4-16.9 months), 8.2 months (95% CI, 5.0-9.7 months), and 4.3 months (95% CI, 2.6-6.7 months), respectively. Multivariate analysis showed that BMV remained the dominant predictor of OS, with a hazard ratio of 2.75 for the high BMV group (95% CI, 1.94-3.89; P<.0001) and a hazard ratio of 1.65 for the intermediate BMV group (95% CI, 1.18-2.30; P<.004). A lower BMV was associated with decreased rates of salvage WBRT (P=.02) and neurologic death (P=.008). Factors predictive for a higher BMV included ≥2 initial brain metastases (P=.004) and melanoma histology (P=.008). Conclusions: BMV is a novel metric associated with OS, neurologic death, and need for salvage WBRT after initial DBF following upfront SRS alone.

  18. An experimental study on acute brain radiation injury: Dynamic changes in proton magnetic resonance spectroscopy and the correlation with histopathology

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hui, E-mail: lihui@sysucc.org.cn [State Key Laboratory of Oncology in Southern China, Guangzhou (China); Medical Imaging and Minimally Invasive Interventional Center, Cancer Center, Sun Yat-sen University, Guangzhou (China); Li, Jian-peng, E-mail: lijp@sysucc.org.cn [Department of Radiology, Dongguan People' s Hospital, Dongguan City (China); Lin, Cheng-guang, E-mail: linchg@sysucc.org.cn [State Key Laboratory of Oncology in Southern China, Guangzhou (China); Department of Radiation Oncology, Cancer Center, Sun Yat-sen University, Guangzhou (China); Liu, Xue-wen, E-mail: liuxw@sysucc.org.cn [State Key Laboratory of Oncology in Southern China, Guangzhou (China); Medical Imaging and Minimally Invasive Interventional Center, Cancer Center, Sun Yat-sen University, Guangzhou (China); Geng, Zhi-jun, E-mail: gengzhj@sysucc.org.cn [State Key Laboratory of Oncology in Southern China, Guangzhou (China); Medical Imaging and Minimally Invasive Interventional Center, Cancer Center, Sun Yat-sen University, Guangzhou (China); Mo, Yun-xian, E-mail: moyx@sysucc.org.cn [State Key Laboratory of Oncology in Southern China, Guangzhou (China); Medical Imaging and Minimally Invasive Interventional Center, Cancer Center, Sun Yat-sen University, Guangzhou (China); Zhang, Rong, E-mail: zhangr@sysucc.org.cn [State Key Laboratory of Oncology in Southern China, Guangzhou (China); Medical Imaging and Minimally Invasive Interventional Center, Cancer Center, Sun Yat-sen University, Guangzhou (China); Xie, Chuan-miao, E-mail: xchuanm@sysucc.org.cn [State Key Laboratory of Oncology in Southern China, Guangzhou (China); Medical Imaging and Minimally Invasive Interventional Center, Cancer Center, Sun Yat-sen University, Guangzhou (China)

    2012-11-15

    Purpose: To investigate the correlation between the alterations of single-voxel {sup 1}H MRS and the histopathological characteristics of radiation brain injury following radiation. Materials and methods: Twenty-seven rabbits were randomized into nine groups to receive radiation with a single dose of 25 Gy. The observation time points included a pre-radiation and 1, 2, 3, 4, 5, 6, 7, and 8 wk following radiation. Each treatment group underwent conventional MRI and single-voxel {sup 1}H MRS, N-acetyl aspartate (NAA), choline (Cho), and creatine (Cr) were observed over the region of interest, and the presence or absence of lactate (Lac) and lipid (Lip) was detected. Histological specimens of each group were obtained after image acquisition. Results: The values of Cho were significantly increased in the first 3 wk, and decreased over the following 5 wk after radiation. Levels of NAA showed a trend toward a decrease 5 wk after radiation. The levels of Cr were not changed between before and after radiation. The Cho/NAA metabolic ratio was significantly increased in weeks 6, 7, and 8 following irradiation, compared to pre-radiation values. Vascular and glial injury appeared on 2 wk after RT in the histology samples, until 4 wk after RT, necrosis of the oligodendrocytes, neuronal degeneration and demyelination could be observed. Conclusions: MRS is sensitive to detect metabolic changes following radiation, and can be used in the early diagnosis of radiation brain injury.

  19. Occupational exposure to radio frequency/microwave radiation and the risk of brain tumors

    DEFF Research Database (Denmark)

    Berg, Gabriele; Spallek, Jacob; Schüz, Joachim

    2006-01-01

    It is still under debate whether occupational exposure to radio frequency/microwave electromagnetic fields (RF/MW-EMF) contributes to the development of brain tumors. This analysis examined the role of occupational RF/MW-EMF exposure in the risk of glioma and meningioma. A population-based, case....... "High" exposure was defined as an occupational exposure that may exceed the RF/MW-EMF exposure limits for the general public recommended by the International Commission on Non-Ionizing Radiation Protection. Multiple conditional logistic regressions were performed separately for glioma and meningioma...

  20. Healthy brain ageing assessed with 18F-FDG PET and age-dependent recovery factors after partial volume effect correction

    Energy Technology Data Exchange (ETDEWEB)

    Bonte, Stijn [IBiTech, Ghent, (Belgium); Ghent University, iMinds - Medical Image and Signal Processing (MEDISIP), Department of Electronics and Information Systems, Ghent (Belgium); University Hospital, Department of Radiology and Nuclear Medicine, Ghent (Belgium); Vandemaele, Pieter; Deblaere, Karel; Goethals, Ingeborg [University Hospital, Department of Radiology and Nuclear Medicine, Ghent (Belgium); Verleden, Stijn; Audenaert, Kurt [University Hospital, Department of Psychiatry, Ghent (Belgium); Holen, Roel van [Ghent University, iMinds - Medical Image and Signal Processing (MEDISIP), Department of Electronics and Information Systems, Ghent (Belgium)

    2017-05-15

    The mechanisms of ageing of the healthy brain are not entirely clarified to date. In recent years several authors have tried to elucidate this topic by using {sup 18}F-FDG positron emission tomography. However, when correcting for partial volume effects (PVE), divergent results were reported. Therefore, it is necessary to evaluate these methods in the presence of atrophy due to ageing. In this paper we first evaluate the performance of two PVE correction techniques with a phantom study: the Rousset method and iterative deconvolution. We show that the ability of the latter method to recover the true activity in a small region decreases with increasing age due to brain atrophy. Next, we have calculated age-dependent recovery factors to correct for this incomplete recovery. These factors were applied to PVE-corrected {sup 18}F-FDG PET scans of healthy subjects for mapping the agedependent metabolism in the brain. Many regions in the brain show a reduced metabolism with ageing, especially in grey matter in the frontal and temporal lobe. An increased metabolism is found in grey matter of the cerebellum and thalamus. Our study resulted in age-dependent recovery factors which can be applied following standard PVE correction methods. Cancelling the effect of atrophy, we found regional changes in {sup 18}F-FDG metabolism with ageing. A decreasing trend is found in the frontal and temporal lobe, whereas an increasing metabolism with ageing is observed in the thalamus and cerebellum.

  1. Estimated clinical benefit of protecting neurogenesis in the developing brain during radiation therapy for pediatric medulloblastoma

    DEFF Research Database (Denmark)

    Blomstrand, M.; Berthelsen, Anne Kiil; Munck af Rosenschöld, Per Martin

    2012-01-01

    to the whole-brain irradiation that is part of standard management. Neurogenesis is very sensitive to radiation, and limiting the radiation dose to the hippocampus and the subventricular zone (SVZ) may preserve neurocognitive function. Radiotherapy plans were created using 4 techniques: standard opposing...... fields, intensity-modulated radiotherapy (IMRT), intensity-modulated arc therapy (IMAT), and intensity-modulated proton therapy (IMPT). Mean dose to the hippocampus and SVZ (mean for both sites) could be limited to 88.3% (range, 83.6%-91.0%), 77.1% (range, 71.5%-81.3%), and 42.3% (range, 26......-modulated proton therapy, thus making this an attractive option to be tested in a prospective clinical trial....

  2. Blood-brain barrier disruption by continuous-wave radio frequency radiation.

    Science.gov (United States)

    Sirav, Bahriye; Seyhan, Nesrin

    2009-01-01

    The increasing use of cellular phones and the increasing number of associated base stations are becoming a widespread source of non ionizing electromagnetic radiation. Some biological effects are likely to occur even at low-level EM fields. This study was designed to investigate the effects of 900 and 1,800 MHz Continuous Wave Radio Frequency Radiation (CW RFR) on the permeability of Blood Brain Barrier (BBB) of rats. Results have shown that 20 min RFR exposure of 900 and 1,800 MHz induces an effect and increases the permeability of BBB of male rats. There was no change in female rats. The scientific evidence on RFR safety or harm remains inconclusive. More studies are needed to demonstrate the effects of RFR on the permeability of BBB and the mechanisms of that breakdown.

  3. Contrasted study on the opening degree of blood-brain barriier after radiation therapy with SPECT and MRI

    International Nuclear Information System (INIS)

    Zhang Qing; Sun Aihua; Hu Yun; Zhang Li; Ye Hengguang

    2004-01-01

    The blood-brain barrier(BBB) is the largest barrier responsible for preventing direct contact between chemotherapeutic drugs in blood and tumors in brain, the permeability of BBB incease at different degree after brain irradiation in clinical brain tumors radiotherapy. Methods: In our study, 26 patients with metastatic brain tumors(21 cases in pr/mary lung carcinoma, 5 cases in breast carcinoma) were accepted the full brain irradiation. The detructive effects of radiation on the BBB were determined by the 99mTc-DTPA SPECT and the concentration ratio of methotrexate(MTX) in cerebrospinal fluid(CSF) and blood, the brain MRI before and after radiotherapy were retrospective contrasted study with SPECT. Results: the degree of destructive effect on the BBB was directly proportional to radiation doses. After a dose of 20Gy radiation to brain, the permeability of BBB inceased markedly(P<0.01). But in cases the dexamethasone(DXM) was administrated to decease the brain edema during radiotherapy, the permeability inceased less than that in patients without DXM(P<0.05). Conclutions: After 20Gy irradiation, the BBB would gradually open. At this time, chemotherapy is the best choice to improving the therapeutic effect. Dexamethasone was found to cause the decease in BBB permeability but no significant remission of brain edema. So, if the combination of radiotherapy and chemotherapy in treatment of metastatic brain tumors will be plan, the dexamethasone may be not used in expecting to deceasing the side effect and that no affecting the therapeutic effect. (authors)

  4. Partial volume correction and image segmentation for accurate measurement of standardized uptake value of grey matter in the brain.

    Science.gov (United States)

    Bural, Gonca; Torigian, Drew; Basu, Sandip; Houseni, Mohamed; Zhuge, Ying; Rubello, Domenico; Udupa, Jayaram; Alavi, Abass

    2015-12-01

    Our aim was to explore a novel quantitative method [based upon an MRI-based image segmentation that allows actual calculation of grey matter, white matter and cerebrospinal fluid (CSF) volumes] for overcoming the difficulties associated with conventional techniques for measuring actual metabolic activity of the grey matter. We included four patients with normal brain MRI and fluorine-18 fluorodeoxyglucose (F-FDG)-PET scans (two women and two men; mean age 46±14 years) in this analysis. The time interval between the two scans was 0-180 days. We calculated the volumes of grey matter, white matter and CSF by using a novel segmentation technique applied to the MRI images. We measured the mean standardized uptake value (SUV) representing the whole metabolic activity of the brain from the F-FDG-PET images. We also calculated the white matter SUV from the upper transaxial slices (centrum semiovale) of the F-FDG-PET images. The whole brain volume was calculated by summing up the volumes of the white matter, grey matter and CSF. The global cerebral metabolic activity was calculated by multiplying the mean SUV with total brain volume. The whole brain white matter metabolic activity was calculated by multiplying the mean SUV for the white matter by the white matter volume. The global cerebral metabolic activity only reflects those of the grey matter and the white matter, whereas that of the CSF is zero. We subtracted the global white matter metabolic activity from that of the whole brain, resulting in the global grey matter metabolism alone. We then divided the grey matter global metabolic activity by grey matter volume to accurately calculate the SUV for the grey matter alone. The brain volumes ranged between 1546 and 1924 ml. The mean SUV for total brain was 4.8-7. Total metabolic burden of the brain ranged from 5565 to 9617. The mean SUV for white matter was 2.8-4.1. On the basis of these measurements we generated the grey matter SUV, which ranged from 8.1 to 11.3. The

  5. Protective effects of edaravone on the radiation response of oligodendrocyte in rats following whole brain irradiation

    International Nuclear Information System (INIS)

    Chen Yingzhu; Tian Ye; Bao Shiyao; Bao Huan; Zhan Zhilin

    2007-01-01

    Objective: To investigate the changes of the oligodendrocyte lineage cells in the cortex following whole brain irradiation and the effects of the neotype free radical scavenger, edaravone on radiation response of oligodendrocyte in rats. Methods: 120 male Sprague Dawley rats were randomly divided into sham- irradiation group, irradiation group and edaravone group. The model of whole-brain irradiation was established with exposure of the whole brain of the rats to 4 MeV X-rays with a single-dose of 10 Gy. The rats were injected intraperitoneally with edaravone at 0.3, 1.0 and 3.0 mg/kg. Tissue microarray of irradiation-induced brain injury in rats was constructed. The expression of A2BS, oligodendrocyte market 4(O4) and 2', 3'-cyclic nucleotide 3'- phosphodiesterase (CNPase) in the cortex was examined by tissue microarray technology and immunohistochemistry. The positive cells were counted. Results: Compared with the sham-irradiation group, the number of A2BS-positive cells increased and the number of O4, CNPase-positive cells decreased significantly at certain time in the irradiation group(P<0.05). Compared with irradiation group, A2BS-positive cells decreased significantly after edaravone treatment, while O4-positive cells and CNPase-positive cells increased significantly (P<0.05, or P<0.01). Conclusions: The number of oligodendrocyte precursor cells in the cortex of rats increased reactively following whole brain irradiation and changed with time. Edaravone played a protective role in oligodendrocyte ischemic reaction in a dose-dependent manner. (authors)

  6. Protective effects of edaravone on the radiation response of oligodendrocyte in rats following whole brain irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yingzhu, Chen; Ye, Tian; Shiyao, Bao; Huan, Bao; Zhilin, Zhan [The Second Affiliated Hospital of Suzhou Univ., Suzhou (China)

    2007-08-15

    Objective: To investigate the changes of the oligodendrocyte lineage cells in the cortex following whole brain irradiation and the effects of the neotype free radical scavenger, edaravone on radiation response of oligodendrocyte in rats. Methods: 120 male Sprague Dawley rats were randomly divided into sham- irradiation group, irradiation group and edaravone group. The model of whole-brain irradiation was established with exposure of the whole brain of the rats to 4 MeV X-rays with a single-dose of 10 Gy. The rats were injected intraperitoneally with edaravone at 0.3, 1.0 and 3.0 mg/kg. Tissue microarray of irradiation-induced brain injury in rats was constructed. The expression of A2BS, oligodendrocyte market 4(O4) and 2', 3'-cyclic nucleotide 3'- phosphodiesterase (CNPase) in the cortex was examined by tissue microarray technology and immunohistochemistry. The positive cells were counted. Results: Compared with the sham-irradiation group, the number of A2BS-positive cells increased and the number of O4, CNPase-positive cells decreased significantly at certain time in the irradiation group(P<0.05). Compared with irradiation group, A2BS-positive cells decreased significantly after edaravone treatment, while O4-positive cells and CNPase-positive cells increased significantly (P<0.05, or P<0.01). Conclusions: The number of oligodendrocyte precursor cells in the cortex of rats increased reactively following whole brain irradiation and changed with time. Edaravone played a protective role in oligodendrocyte ischemic reaction in a dose-dependent manner. (authors)

  7. Erlotinib Versus Radiation Therapy for Brain Metastases in Patients With EGFR-Mutant Lung Adenocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Gerber, Naamit K.; Yamada, Yoshiya; Rimner, Andreas [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Shi, Weiji [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Riely, Gregory J. [Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Beal, Kathryn [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Yu, Helena A. [Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Chan, Timothy A. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Zhang, Zhigang [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Wu, Abraham J., E-mail: wua@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

    2014-06-01

    Purpose/Objectives: Radiation therapy (RT) is the principal modality in the treatment of patients with brain metastases (BM). However, given the activity of EGFR tyrosine kinase inhibitors in the central nervous system, it is uncertain whether upfront brain RT is necessary for patients with EGFR-mutant lung adenocarcinoma with BM. Methods and Materials: Patients with EGFR-mutant lung adenocarcinoma and newly diagnosed BM were identified. Results: 222 patients were identified. Exclusion criteria included prior erlotinib use, presence of a de novo erlotinib resistance mutation, or incomplete data. Of the remaining 110 patients, 63 were treated with erlotinib, 32 with whole brain RT (WBRT), and 15 with stereotactic radiosurgery (SRS). The median overall survival (OS) for the whole cohort was 33 months. There was no significant difference in OS between the WBRT and erlotinib groups (median, 35 vs 26 months; P=.62), whereas patients treated with SRS had a longer OS than did those in the erlotinib group (median, 64 months; P=.004). The median time to intracranial progression was 17 months. There was a longer time to intracranial progression in patients who received WBRT than in those who received erlotinib upfront (median, 24 vs 16 months, P=.04). Patients in the erlotinib or SRS group were more likely to experience intracranial failure as a component of first failure, whereas WBRT patients were more likely to experience failure outside the brain (P=.004). Conclusions: The survival of patients with EGFR-mutant adenocarcinoma with BM is notably long, whether they receive upfront erlotinib or brain RT. We observed longer intracranial control with WBRT, even though the WBRT patients had a higher burden of intracranial disease. Despite the equivalent survival between the WBRT and erlotinib group, this study underscores the role of WBRT in producing durable intracranial control in comparison with a targeted biologic agent with known central nervous system activity.

  8. Radiation damage to the normal monkey brain. Experimental study induced by interstitial irradiation

    International Nuclear Information System (INIS)

    Mishima, Nobuya; Tamiya, Takashi; Matsumoto, Kengo; Furuta, Tomohisa; Ohmoto, Takashi

    2003-01-01

    Radiation damage to normal brain tissue induced by interstitial irradiation with iridium-192 seeds was sequentially evaluated by computed tomography (CT), magnetic resonance imaging (MRI), and histological examination. This study was carried out in 14 mature Japanese monkeys. The experimental area received more than 200-260 Gy of irradiation developed coagulative necrosis. Infiltration of macrophages to the periphery of the necrotic area was seen. In addition, neovascularization, hyalinization of vascular walls, and gliosis were found in the periphery of the area invaded by the macrophages. All sites at which the vascular walls were found to have acute stage fibrinoid necrosis eventually developed coagulative necrosis. The focus of necrosis was detected by MRI starting 1 week after the end of radiation treatment, and the size of the necrotic area did not change for 6 months. The peripheral areas showed clear ring enhancement with contrast material. Edema surrounding the lesions was the most significant 1 week after radiation and was reduced to a minimum level 1 month later. However, the edema then expanded once again and was sustained for as long as 6 months. CT did not provide as clear of a presentation as MRI, but it did reveal similar findings for the most part, and depicted calcification in the necrotic area. This experimental model is considered useful for conducting basic research on brachytherapy, as well as for achieving a better understanding of delayed radiation necrosis. (author)

  9. Three-Year Outcomes of a Canadian Multicenter Study of Accelerated Partial Breast Irradiation Using Conformal Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Berrang, Tanya S., E-mail: tberrang@bccancer.bc.ca [British Columbia Cancer Agency-Vancouver Island, BC (Canada); University of British Columbia, BC (Canada); Olivotto, Ivo [British Columbia Cancer Agency-Vancouver Island, BC (Canada); University of British Columbia, BC (Canada); Kim, Do-Hoon [Juravinski Cancer Centre, Ontario (Canada); McMaster University, Ontario (Canada); Nichol, Alan [British Columbia Cancer Agency-Vancouver Centre, BC (Canada); University of British Columbia, BC (Canada); Cho, B.C. John [Princess Margaret Hospital, Ontario (Canada); University of Toronto, Ontario (Canada); Mohamed, Islam G. [British Columbia Cancer Agency-Southern Interior, BC (Canada); University of British Columbia, BC (Canada); Parhar, Tarnjit [British Columbia Cancer Agency-Vancouver Centre, BC (Canada); University of British Columbia, BC (Canada); Wright, J.R. [Juravinski Cancer Centre, Ontario (Canada); McMaster University, Ontario (Canada); Truong, Pauline [British Columbia Cancer Agency-Vancouver Island, BC (Canada); University of British Columbia, BC (Canada); Tyldesley, Scott [British Columbia Cancer Agency-Vancouver Centre, BC (Canada); University of British Columbia, BC (Canada); Sussman, Jonathan [Juravinski Cancer Centre, Ontario (Canada); McMaster University, Ontario (Canada); Wai, Elaine [British Columbia Cancer Agency-Vancouver Island, BC (Canada); University of British Columbia, BC (Canada); Whelan, Tim [Juravinski Cancer Centre, Ontario (Canada); McMaster University, Ontario (Canada)

    2011-12-01

    Purpose: To report 3-year toxicity, cosmesis, and efficacy of a multicenter study of external beam, accelerated partial breast irradiation (APBI) for early-stage breast cancer. Methods and Materials: Between March 2005 and August 2006, 127 women aged {>=}40 years with ductal carcinoma in situ or node-negative invasive breast cancer {<=}3 cm in diameter, treated with breast-conserving surgery achieving negative margins, were accrued to a prospective study involving five Canadian cancer centers. Women meeting predefined dose constraints were treated with APBI using 3 to 5 photon beams, delivering 35 to 38.5 Gy in 10 fractions, twice a day, over 1 week. Patients were assessed for treatment-related toxicities, cosmesis, and efficacy before APBI and at specified time points for as long as 3 years after APBI. Results: 104 women had planning computed tomography scans showing visible seromas, met dosimetric constraints, and were treated with APBI to doses of 35 Gy (n = 9), 36 Gy (n = 33), or 38.5 Gy (n = 62). Eighty-seven patients were evaluated with minimum 3-year follow-up after APBI. Radiation dermatitis, breast edema, breast induration, and fatigue decreased from baseline levels or stabilized by the 3-year follow-up. Hypopigmentation, hyperpigmentation, breast pain, and telangiectasia slightly increased from baseline levels. Most toxicities at 3 years were Grade 1. Only 1 patient had a Grade 3 toxicity with telangiectasia in a skin fold inside the 95% isodose. Cosmesis was good to excellent in 86% (89/104) of women at baseline and 82% (70/85) at 3 years. The 3-year disease-free survival was 97%, with only one local recurrence that occurred in a different quadrant away from the treated site and two distant recurrences. Conclusions: At 3 years, toxicity and cosmesis were acceptable, and local control and disease-free survival were excellent, supporting continued accrual to randomized APBI trials.

  10. No late effect of ionizing radiation on the aging-related oxidative changes in the mouse brain

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Beom Su; Kim, Seol Wha; Jung, U Hee; Jo, Sung Kee [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2010-09-15

    Radiation-induced late injury to normal tissue is a primary area of radiation biology research. The present study was undertaken to investigate whether the late effect of the ionizing radiation appears as an age-related oxidative status in the brain. Three groups of 4-month old C57BL/6 mice that were exposed to {sup 137}Cs {gamma}-rays at a single dose (5 Gy) or fractionated doses (1 Gy x 5 times, or 0,2 Gy x 25 times) at 2 months old were investigated for the oxidative status of their brains with both young (2-month) and old (24-month) mice. A significant (pbrains compared with that of the young mice. Malondialdehyde (MDA) content was significantly (p<0.05) increased in the old mice brain. However, any significant difference in SOD activity and MDA contents of the irradiated brain was not observed compared to age-matched control group mice. SOD activity and MDA content were observed within good parameters of brain aging and there no late effects on the age-related oxidative level in the {gamma}-ray irradiated mice brains.

  11. No late effect of ionizing radiation on the aging-related oxidative changes in the mouse brain

    International Nuclear Information System (INIS)

    Jang, Beom Su; Kim, Seol Wha; Jung, U Hee; Jo, Sung Kee

    2010-01-01

    Radiation-induced late injury to normal tissue is a primary area of radiation biology research. The present study was undertaken to investigate whether the late effect of the ionizing radiation appears as an age-related oxidative status in the brain. Three groups of 4-month old C57BL/6 mice that were exposed to 137 Cs γ-rays at a single dose (5 Gy) or fractionated doses (1 Gy x 5 times, or 0,2 Gy x 25 times) at 2 months old were investigated for the oxidative status of their brains with both young (2-month) and old (24-month) mice. A significant (p< o.05) decrease in superoxide dismutase (SOD) activity was observed in old mice brains compared with that of the young mice. Malondialdehyde (MDA) content was significantly (p<0.05) increased in the old mice brain. However, any significant difference in SOD activity and MDA contents of the irradiated brain was not observed compared to age-matched control group mice. SOD activity and MDA content were observed within good parameters of brain aging and there no late effects on the age-related oxidative level in the γ-ray irradiated mice brains

  12. Evaluation of acute radiation damage of the human brain by 1H-MRS

    International Nuclear Information System (INIS)

    Matsushima, Shigeru; Kinosada, Yasutomi.

    1993-01-01

    Fourteen patients (17 cases) were treated with the whole brain irradiation. Physiological changes in white matter were measured by in vivo 1 H magnetic resonance spectroscopy ( 1 H-MRS). Phantom examination proved the accuracy of our 1 H-MRS method to be valid. The measurement was performed 2 or 3 times in each case at the radiation doses ranging from 0 to 40 Gy with 2 Gy daily fractionation. For the measurement of 1 H-MRS, 1.5 T whole body MR system was used and stimulated echo acquisition mode (STEAM) with chemical shift selective (CHESS) pulse was applied. Volume of the interest (VOI) was 2.5x2.5x2.5 cm 3 , and the repetition time and echo time were 2000 ms and 272 ms, respectively. Acute radiation damage of the brain was evaluated by the change of peak area ratio (PAR) of choline, creatine and N-acetyl aspartate (NAA). 1 H-MRS spectra before irradiation were different from those observed during irradiation. There were statistically significant (p 1 H-MRS is a powerful modality, detecting the subtle physiological change which is difficult to evaluate with conventional images. (author)

  13. Radiation control in the intensive care unit for high intensity iridium-192 brain implants

    International Nuclear Information System (INIS)

    Sewchand, W.; Drzymala, R.E.; Amin, P.P.; Salcman, M.; Salazar, O.M.

    1987-01-01

    A bedside lead cubicle was designed to minimize the radiation exposure of intensive care unit staff during routine interstitial brain irradiation by removable, high intensity iridium-192. The cubicle shields the patient without restricting intensive care routines. The design specifications were confirmed by exposure measurements around the shield with an implanted anthropomorphic phantom simulating the patient situation. The cubicle reduces the exposure rate around an implant patient by as much as 90%, with the exposure level not exceeding 0.1 mR/hour/mg of radium-equivalent 192 Ir. Evaluation of data accumulated for the past 3 years has shown that the exposure levels of individual attending nurses are 0.12 to 0.36 mR/mg of radium-equivalent 192 Ir per 12-hour shift. The corresponding range for entire nursing teams varies between 0.18 and 0.26. A radiation control index (exposure per mg of radium-equivalent 192 Ir per nurse-hour) is thus defined for individual nurses and nursing teams; this index is a significant guide to the planning of nurse rotations for brain implant patients with various 192 Ir loads. The bedside shield reduces exposure from 192 Ir implants by a factor of about 20, as expected, and the exposure from the lower energy radioisotope iodine-125 is barely detectable

  14. Affinity purification and partial characterization of the zonulin/zonula occludens toxin (Zot) receptor from human brain.

    Science.gov (United States)

    Lu, R; Wang, W; Uzzau, S; Vigorito, R; Zielke, H R; Fasano, A

    2000-01-01

    The intercellular tight junctions (TJs) of endothelial cells represent the limiting structure for the permeability of the blood-brain barrier (BBB). Although the BBB has been recognized as being the interface between the bloodstream and the brain, little is known about its regulation. Zonulin and its prokaryotic analogue, zonula occludens toxin (Zot) elaborated by Vibrio cholerae, both modulate intercellular TJs by binding to a specific surface receptor with subsequent activation of an intracellular signaling pathway involving phospholipase C and protein kinase C activation and actin polymerization. Affinity column purification revealed that human brain plasma membrane preparations contain two Zot binding proteins of approximately 55 and approximately 45 kDa. Structural and kinetic studies, including saturation and competitive assays, identified the 55-kDa protein as tubulin, whereas the 45-kDa protein represents the zonulin/Zot receptor. Biochemical characterization provided evidence that this receptor is a glycoprotein containing multiple sialic acid residues. Comparison of the N-terminal sequence of the zonulin/Zot receptor with other protein sequences by BLAST analysis revealed a striking similarity with MRP-8, a 14-kDa member of the S-100 family of calcium binding proteins. The discovery and characterization of this receptor from human brain may significantly contribute to our knowledge on the pathophysiological regulation of the BBB.

  15. Partially flexible MEMS neural probe composed of polyimide and sucrose gel for reducing brain damage during and after implantation

    International Nuclear Information System (INIS)

    Jeon, Myounggun; Yoon, Eui-Sung; Cho, Il-Joo; Cho, Jeiwon; Jung, Dahee; Kim, Yun Kyung; Shin, Sehyun

    2014-01-01

    This paper presents a flexible microelectromechanical systems (MEMS) neural probe that minimizes neuron damage and immune response, suitable for chronic recording applications. MEMS neural probes with various features such as high electrode densities have been actively investigated for neuron stimulation and recording to study brain functions. However, successful recording of neural signals in chronic application using rigid silicon probes still remains challenging because of cell death and macrophages accumulated around the electrodes over time from continuous brain movement. Thus, in this paper, we propose a new flexible MEMS neural probe that consists of two segments: a polyimide-based, flexible segment for connection and a rigid segment composed of thin silicon for insertion. While the flexible connection segment is designed to reduce the long-term chronic neuron damage, the thin insertion segment is designed to minimize the brain damage during the insertion process. The proposed flexible neural probe was successfully fabricated using the MEMS process on a silicon on insulator wafer. For a successful insertion, a biodegradable sucrose gel is coated on the flexible segment to temporarily increase the probe stiffness to prevent buckling. After the insertion, the sucrose gel dissolves inside the brain exposing the polyimide probe. By performing an insertion test, we confirm that the flexible probe has enough stiffness. In addition, by monitoring immune responses and brain histology, we successfully demonstrate that the proposed flexible neural probe incurs fivefold less neural damage than that incurred by a conventional silicon neural probe. Therefore, the presented flexible neural probe is a promising candidate for recording stable neural signals for long-time chronic applications. (paper)

  16. Synchrotron microbeam radiation therapy induces hypoxia in intracerebral gliosarcoma but not in the normal brain

    International Nuclear Information System (INIS)

    Bouchet, Audrey; Lemasson, Benjamin; Christen, Thomas; Potez, Marine; Rome, Claire; Coquery, Nicolas; Le Clec’h, Céline; Moisan, Anaick; Bräuer-Krisch, Elke; Leduc, Géraldine; Rémy, Chantal; Laissue, Jean A.; Barbier, Emmanuel L.; Brun, Emmanuel; Serduc, Raphaël

    2013-01-01

    Purpose: Synchrotron microbeam radiation therapy (MRT) is an innovative irradiation modality based on spatial fractionation of a high-dose X-ray beam into lattices of microbeams. The increase in lifespan of brain tumor-bearing rats is associated with vascular damage but the physiological consequences of MRT on blood vessels have not been described. In this manuscript, we evaluate the oxygenation changes induced by MRT in an intracerebral 9L gliosarcoma model. Methods: Tissue responses to MRT (two orthogonal arrays (2 × 400 Gy)) were studied using magnetic resonance-based measurements of local blood oxygen saturation (MR S O 2 ) and quantitative immunohistology of RECA-1, Type-IV collagen and GLUT-1, marker of hypoxia. Results: In tumors, MR S O 2 decreased by a factor of 2 in tumor between day 8 and day 45 after MRT. This correlated with tumor vascular remodeling, i.e. decrease in vessel density, increases in half-vessel distances (×5) and GLUT-1 immunoreactivity. Conversely, MRT did not change normal brain MR S O 2 , although vessel inter-distances increased slightly. Conclusion: We provide new evidence for the differential effect of MRT on tumor vasculature, an effect that leads to tumor hypoxia. As hypothesized formerly, the vasculature of the normal brain exposed to MRT remains sufficiently perfused to prevent any hypoxia

  17. Brain tumors in children: long-term survival after radiation treatment

    Energy Technology Data Exchange (ETDEWEB)

    Jenkin, Derek; Greenberg, Mark; Hoffman, Harold; Hendrick, Bruce; Humphreys, Robin; Vatter, Annette

    1995-02-01

    Purpose: To determine the cause of death in children who survive more than 5 years after radiation treatment of a brain tumor. Methods and Material: Nine hundred and twelve consecutive children with a primary brain tumor irradiated at the Princess Margaret Hospital or Toronto-Bayview Regional Cancer Center from 1958 to 1991, were evaluated for long-term outcome. Results: Overall 10- and 20-year survival rates were 44% and 37%. Subsequent survival of 377 5-year survivors was, at an additional 10 and 20 years, 78% and 67%. Most (83%) deaths that occurred more than 5 years from diagnosis were a result of relapse of the original tumor. The 10-year survival rate subsequent to relapse was 9% when the first relapse occurred less than one year from diagnosis, 17% for 1-2 years, and 31% when the time to relapse was 3 years or greater. The cumulative actuarial incidence of, and death from, second malignant tumors at 30 years from diagnosis was 18% and 13%, respectively. Conclusions: Death later than 5 years from diagnosis of a brain tumor in children is common and is usually due to progressive disease in slowly evolving low grade tumors. Death from a second malignant tumor becomes more frequent than death from the original tumor after 15 years from diagnosis.

  18. MRI findings of radiation encephalopathy of brain stem after radiotherapy for nasopharyngeal cancer

    International Nuclear Information System (INIS)

    Liang Changhong; Li Guoye; Huang Biao; Huang Meiping; Zheng Junhui; Tan Shaoheng; Zeng Qiongxin

    1998-01-01

    Purpose: To study MRI findings and clinical manifestation of radiation encephalopathy (RE) of brain stem. Methods: MRI findings and clinical symptoms in 51 patients with RE of brain stem after radiotherapy for nasopharyngeal cancer were reviewed. Results: Clinical symptoms included number weakness or paralysis in the limbs and symptoms of damaged cranial nerves. All lesions appeared hypo- or iso-intense on spin echo(SE) T 1 -weighted images and inhomogeneous and mixed hyper- and iso-intense on Turbo spin echo (TSE) T 2 -weighted images. The lesions were located in mesencephalon, pons, medulla, basilar part of pons, basilar part of pons and medulla oblongata in 2,7,3,9 and 30 patients respectively. The enhancement patterns included irregular rings in 39 patients, spotty in 3 and no enhancement in 9 patients. Mass effect was minimal in all patients. On follow-up MRI, the lesions disappeared in 4 patients, did not change in size and shape in 8 patients and enlarged in 2 patients. Conclusion: MRI could demonstrate the characteristic findings of RE of brain stem. MRI findings sometimes are not consistent with the clinical symptoms

  19. Radiation-induced apoptosis in undifferentiated cells of the developing brain as a biological defense mechanism

    International Nuclear Information System (INIS)

    Inouye, Minioru; Tamaru, Masao.

    1994-01-01

    Undifferentiated neural (UN) cells of the developing mammalian brain are highly sensitive to the lethal effects of ionizing radiation. Nuclear and cytoplasmic condensation, transglutaminase activation, and internucleosomal DNA cleavage reveal radiation-induced cell death in the ventricular zone of the cerebral mantle and external granular layer of the cerebellum to be due to apoptosis. A statistically significant increase of cell mortality can be induced by 0.03 Gy X-irradiation, and the mortality increases linearly with increasing doses. It is not changed by split doses, probably because of the very slow repair of cellular damage and a lack of adaptive response. Although extensive apoptosis in the UN cell population results in microcephaly and mental retardation, it possesses the ability to recover from a considerable cell loss and to form the normal structure of the central nervous system. The number of cell deaths needed to induce tissue adnormalities in the adult murine brain rises in the range of 15-25% of the germinal cell population; with the threshold doses at about 0.3 Gy for cerebral anomalies and 1 Gy for cerebellar abnormalities. Threshold level is similarly suggested in prenatally exposed A-bomb survivors. High radiosensitivity of UN cells is assumed to be a manifestation of the ability of the cell to commit suicide when injured. Repeated replication of DNA and extensive gene expression are required in future proliferation and differentiation. Once an abnormality in DNA was induced and fixed in the UN cell, it would be greatly amplified and prove a danger in producing malformations and tumors. These cells would thus commit suicide for the benefit of the individual to eliminate their acquired genetic abnormalities rather than make DNA repair. UN cells in the developing brain are highly radiosensitive and readily involved in apoptosis. Paradoxically, however, this may be to protect individuals against teratogenesis and tumorigenesis. (J.P.N.)

  20. Radiation-induced apoptosis in undifferentiated cells of the developing brain as a biological defense mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Inouye, Minioru [Nagoya Univ. (Japan). Research Inst. of Environmental Medicine; Tamaru, Masao

    1994-12-31

    Undifferentiated neural (UN) cells of the developing mammalian brain are highly sensitive to the lethal effects of ionizing radiation. Nuclear and cytoplasmic condensation, transglutaminase activation, and internucleosomal DNA cleavage reveal radiation-induced cell death in the ventricular zone of the cerebral mantle and external granular layer of the cerebellum to be due to apoptosis. A statistically significant increase of cell mortality can be induced by 0.03 Gy X-irradiation, and the mortality increases linearly with increasing doses. It is not changed by split doses, probably because of the very slow repair of cellular damage and a lack of adaptive response. Although extensive apoptosis in the UN cell population results in microcephaly and mental retardation, it possesses the ability to recover from a considerable cell loss and to form the normal structure of the central nervous system. The number of cell deaths needed to induce tissue adnormalities in the adult murine brain rises in the range of 15-25% of the germinal cell population; with the threshold doses at about 0.3 Gy for cerebral anomalies and 1 Gy for cerebellar abnormalities. Threshold level is similarly suggested in prenatally exposed A-bomb survivors. High radiosensitivity of UN cells is assumed to be a manifestation of the ability of the cell to commit suicide when injured. Repeated replication of DNA and extensive gene expression are required in future proliferation and differentiation. Once an abnormality in DNA was induced and fixed in the UN cell, it would be greatly amplified and prove a danger in producing malformations and tumors. These cells would thus commit suicide for the benefit of the individual to eliminate their acquired genetic abnormalities rather than make DNA repair. UN cells in the developing brain are highly radiosensitive and readily involved in apoptosis. Paradoxically, however, this may be to protect individuals against teratogenesis and tumorigenesis. (J.P.N.).

  1. Partial Loss of the Glutamate Transporter GLT-1 Alters Brain Akt and Insulin Signaling in a Mouse Model of Alzheimer's Disease.

    Science.gov (United States)

    Meeker, Kole D; Meabon, James S; Cook, David G

    2015-01-01

    The glutamate transporter GLT-1 (also called EAAT2 in humans) plays a critical role in regulating extracellular glutamate levels in the central nervous system (CNS). In Alzheimer's disease (AD), EAAT2 loss is associated with neuropathology and cognitive impairment. In keeping with this, we have reported that partial GLT-1 loss (GLT-1+/-) causes early-occurring cognitive deficits in mice harboring familial AD AβPPswe/PS1ΔE9 mutations. GLT-1 plays important roles in several molecular pathways that regulate brain metabolism, including Akt and insulin signaling in astrocytes. Significantly, AD pathogenesis also involves chronic Akt activation and reduced insulin signaling in the CNS. In this report we tested the hypothesis that GLT-1 heterozygosity (which reduces GLT-1 to levels that are comparable to losses in AD patients) in AβPPswe/PS1ΔE9 mice would induce sustained activation of Akt and disturb components of the CNS insulin signaling cascade. We found that partial GLT-1 loss chronically increased Akt activation (reflected by increased phosphorylation at serine 473), impaired insulin signaling (reflected by decreased IRβ phosphorylation of tyrosines 1150/1151 and increased IRS-1 phosphorylation at serines 632/635 - denoted as 636/639 in humans), and reduced insulin degrading enzyme (IDE) activity in brains of mice expressing familial AβPPswe/PS1ΔE9 AD mutations. GLT-1 loss also caused an apparent compensatory increase in IDE activity in the liver, an organ that has been shown to regulate peripheral amyloid-β levels and expresses GLT-1. Taken together, these findings demonstrate that partial GLT-1 loss can cause insulin/Akt signaling abnormalities that are in keeping with those observed in AD.

  2. Comparison of doses received by the hippocampus in patients treated with single isocenter– vs multiple isocenter–based stereotactic radiation therapy to the brain for multiple brain metastases

    International Nuclear Information System (INIS)

    Algan, Ozer; Giem, Jared; Young, Julie; Ali, Imad; Ahmad, Salahuddin; Hossain, Sabbir

    2015-01-01

    To investigate the doses received by the hippocampus and normal brain tissue during a course of stereotactic radiation therapy using a single isocenter (SI)–based or multiple isocenter (MI)–based treatment planning in patients with less than 4 brain metastases. In total, 10 patients with magnetic resonance imaging (MRI) demonstrating 2-3 brain metastases were included in this retrospective study, and 2 sets of stereotactic intensity-modulated radiation therapy (IMRT) treatment plans (SI vs MI) were generated. The hippocampus was contoured on SPGR sequences, and doses received by the hippocampus and the brain were calculated and compared between the 2 treatment techniques. A total of 23 lesions in 10 patients were evaluated. The median tumor volume, the right hippocampus volume, and the left hippocampus volume were 3.15, 3.24, and 2.63 mL, respectively. In comparing the 2 treatment plans, there was no difference in the planning target volume (PTV) coverage except in the tail for the dose-volume histogram (DVH) curve. The only statistically significant dosimetric parameter was the V_1_0_0. All of the other measured dosimetric parameters including the V_9_5, V_9_9, and D_1_0_0 were not significantly different between the 2 treatment planning techniques. None of the dosimetric parameters evaluated for the hippocampus revealed any statistically significant difference between the MI and SI plans. The total brain doses were slightly higher in the SI plans, especially in the lower dose region, although this difference was not statistically different. The use of SI-based treatment plan resulted in a 35% reduction in beam-on time. The use of SI treatments for patients with up to 3 brain metastases produces similar PTV coverage and similar normal tissue doses to the hippocampus and the brain when compared with MI plans. SI treatment planning should be considered in patients with multiple brain metastases undergoing stereotactic treatment.

  3. Comparison of doses received by the hippocampus in patients treated with single isocenter- vs multiple isocenter-based stereotactic radiation therapy to the brain for multiple brain metastases.

    Science.gov (United States)

    Algan, Ozer; Giem, Jared; Young, Julie; Ali, Imad; Ahmad, Salahuddin; Hossain, Sabbir

    2015-01-01

    To investigate the doses received by the hippocampus and normal brain tissue during a course of stereotactic radiation therapy using a single isocenter (SI)-based or multiple isocenter (MI)-based treatment planning in patients with less than 4 brain metastases. In total, 10 patients with magnetic resonance imaging (MRI) demonstrating 2-3 brain metastases were included in this retrospective study, and 2 sets of stereotactic intensity-modulated radiation therapy (IMRT) treatment plans (SI vs MI) were generated. The hippocampus was contoured on SPGR sequences, and doses received by the hippocampus and the brain were calculated and compared between the 2 treatment techniques. A total of 23 lesions in 10 patients were evaluated. The median tumor volume, the right hippocampus volume, and the left hippocampus volume were 3.15, 3.24, and 2.63mL, respectively. In comparing the 2 treatment plans, there was no difference in the planning target volume (PTV) coverage except in the tail for the dose-volume histogram (DVH) curve. The only statistically significant dosimetric parameter was the V100. All of the other measured dosimetric parameters including the V95, V99, and D100 were not significantly different between the 2 treatment planning techniques. None of the dosimetric parameters evaluated for the hippocampus revealed any statistically significant difference between the MI and SI plans. The total brain doses were slightly higher in the SI plans, especially in the lower dose region, although this difference was not statistically different. The use of SI-based treatment plan resulted in a 35% reduction in beam-on time. The use of SI treatments for patients with up to 3 brain metastases produces similar PTV coverage and similar normal tissue doses to the hippocampus and the brain when compared with MI plans. SI treatment planning should be considered in patients with multiple brain metastases undergoing stereotactic treatment. Copyright © 2015 American Association of

  4. Comparison of doses received by the hippocampus in patients treated with single isocenter– vs multiple isocenter–based stereotactic radiation therapy to the brain for multiple brain metastases

    Energy Technology Data Exchange (ETDEWEB)

    Algan, Ozer, E-mail: oalgan@ouhsc.edu; Giem, Jared; Young, Julie; Ali, Imad; Ahmad, Salahuddin; Hossain, Sabbir

    2015-01-01

    To investigate the doses received by the hippocampus and normal brain tissue during a course of stereotactic radiation therapy using a single isocenter (SI)–based or multiple isocenter (MI)–based treatment planning in patients with less than 4 brain metastases. In total, 10 patients with magnetic resonance imaging (MRI) demonstrating 2-3 brain metastases were included in this retrospective study, and 2 sets of stereotactic intensity-modulated radiation therapy (IMRT) treatment plans (SI vs MI) were generated. The hippocampus was contoured on SPGR sequences, and doses received by the hippocampus and the brain were calculated and compared between the 2 treatment techniques. A total of 23 lesions in 10 patients were evaluated. The median tumor volume, the right hippocampus volume, and the left hippocampus volume were 3.15, 3.24, and 2.63 mL, respectively. In comparing the 2 treatment plans, there was no difference in the planning target volume (PTV) coverage except in the tail for the dose-volume histogram (DVH) curve. The only statistically significant dosimetric parameter was the V{sub 100}. All of the other measured dosimetric parameters including the V{sub 95}, V{sub 99}, and D{sub 100} were not significantly different between the 2 treatment planning techniques. None of the dosimetric parameters evaluated for the hippocampus revealed any statistically significant difference between the MI and SI plans. The total brain doses were slightly higher in the SI plans, especially in the lower dose region, although this difference was not statistically different. The use of SI-based treatment plan resulted in a 35% reduction in beam-on time. The use of SI treatments for patients with up to 3 brain metastases produces similar PTV coverage and similar normal tissue doses to the hippocampus and the brain when compared with MI plans. SI treatment planning should be considered in patients with multiple brain metastases undergoing stereotactic treatment.

  5. Effect of runway training on rat brain tyrosine hydroxylase: differential effect of continuous and partial reinforcement schedules.

    Science.gov (United States)

    Boarder, M R; Feldon, J; Gray, J A; Fillenz, M

    1979-12-01

    Previous experiments have implicated ascending noradrenergic systems in the development of the behavioural responses to different patterns of reward. In this report food deprived male Sprague--Dawley rats were trained to run a straight alley for good reward on a continuous reinforcement (CRF) or a partial reinforcement (PRF) schedule. Tyrosine hydroxylase measured in a partially solubilized preparation from hippocampus and hypothalamus at the end of acquisition was not different from controls, indicating that enzyme induction does not occur during either training schedules. However, hippocampal synaptosomal tyrosine hydroxylation rates from the CRF group was significantly higher than from either the PRF group or the handled controls. This indicates that at the end of the acquisition schedule the noradrenergic projection to hippocampus was more active in the CRF group than with the PRF group or the handled control.

  6. Long-term effects of whole brain radiation on intellectual function in children with medulloblastoma

    International Nuclear Information System (INIS)

    Uozumi, Akimasa; Okimura, Yoshitaka; Ohsato, Katsunobu; Yamaura, Akira; Hasegawa, Keiko

    1992-01-01

    Neuropsychological tests were administered to four children 4 to 10 years after treatment of medulloblastoma with surgery, radiation, and natural alpha-interferon. The age at the time of treatment ranged from 2 years and 4 months to 11 years. The radiation doses were 26-34 Gy to the whole brain, 48-52 Gy to the posterior fossa and 26-34 Gy to the whole spine. Uneventful follow-up periods ranged from 4 years and 8 months to 10 years and 6 months. At present they attend regular classes at local schools. The neuropsychological tests used were: Wechsler Intelligence Scale for Children-Revised (WISC-R), Frostig developmental test of visual perception and Uchida-Kraepelin psychometric test. The WISC-R showed a marked decrease of full-scale IQ in two of the four children (scores of 72 and 73). Their performance IQ scores were significantly lower than their verbal scores. This may reflect less ability to manage visual and spatial information than verbal information. The other two patients had full-scale IQ scores of 91 and 92 (within the normal range). The test of visual perception showed decreased ability in the three patients who were younger than 8 years, of age at the time of treatment but normal ability in the child who had been treated at 11 years of age. The Uchida-Kraepelin test showed reduced amounts of work accomplished and poor learning ability in all four patients. These findings suggest that intellectual function in children with medulloblastoma is affected by the failure of visual perception to develop normally because of whole brain radiation at an early age and that their problem is aggravated by secondary learning difficulties. It is necessary to provide these patients with individual learning programs based on the results of neuropsychological evaluations. (author)

  7. A benchmark analysis of radiation flux distribution for Boron Neutron Capture Therapy of canine brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Moran, Jean M. [Univ. of Idaho, Idaho Falls, ID (United States)

    1992-02-01

    Calculations of radiation flux and dose distributions for Boron Neutron Capture Therapy (BNCT) of brain tumors are typically performed using sophisticated three-dimensional analytical models based on either a homogeneous approximation or a simplified few-region approximation to the actual highly-heterogeneous geometry of the irradiation volume. Such models should be validated by comparison with calculations using detailed models in which all significant macroscopic tissue heterogeneities and geometric structures are explicitly represented as faithfully as possible. This work describes a validation exercise for BNCT of canine brain tumors. Geometric measurements of the canine anatomical structures of interest for this work were performed by dissecting and examining two essentially identical Labrador Retriever heads. Chemical analyses of various tissue samples taken during the dissections were conducted to obtain measurements of elemental compositions for tissues of interest. The resulting geometry and tissue composition data were then used to construct a detailed heterogeneous calculational model of the Labrador Retriever head. Calculations of three-dimensional radiation flux distributions pertinent to BNCT were performed for the model using the TORT discrete-ordinates radiation transport code. The calculations were repeated for a corresponding volume-weighted homogeneous tissue model. Comparison of the results showed that the peak neutron and photon flux magnitudes were quite similar for the two models (within 5%), but that the spatial flux profiles were shifted in the heterogeneous model such that the fluxes in some locations away from the peak differed from the corresponding fluxes in the homogeneous model by as much as 10-20%. Differences of this magnitude can be therapeutically significant, emphasizing the need for proper validation of simplified treatment planning models.

  8. The lazaroid U74389G protects normal brain from stereotactic radiosurgery-induced radiation injury

    International Nuclear Information System (INIS)

    Buatti, John M.; Friedman, William A.; Theele, Daniel P.; Bova, Francis J.; Mendenhall, William M.

    1996-01-01

    Purpose: To test an established model of stereotactic radiosurgery-induced radiation injury with pretreatments of either methylprednisolone or the lazaroid U74389G. Methods and Materials: Nine cats received stereotactic radiosurgery with a linear accelerator using an animal radiosurgery device. Each received a dose of 125.0 Gy prescribed to the 84% isodose shell to the anterior limb of the right internal capsule. One animal received no pretreatment, two received citrate vehicle, three received 30 mg/kg of methylprednisolone, and three received 5 mg/kg of U74389G. After irradiation, the animals had frequent neurologic examinations, and neurologic deficits developed in all of them. Six months after the radiation treatment, the animals were anesthetized, and had gadolinium-enhanced magnetic resonance (MR) scans, followed by Evans blue dye perfusion, euthanasia, and brain fixation. Results: Magnetic resonance scans revealed a decrease in the size of the lesions from a mean volume of 0.45 ± 0.06 cm 3 in the control, vehicle-treated, and methylprednisolone-treated animals to 0.22 ± 0.14 cm 3 in the U74389G-treated group. The scans also suggested the absence of necrosis and ventricular dilatation in the lazaroid-treated group. Gross pathology revealed that lesions produced in the untreated, vehicle-treated, and methylprednisolone-treated cats were similar and were characterized by a peripheral zone of Evans blue dye staining with a central zone of a mature coagulative necrosis and focal hemorrhage. However, in the U74389G-treated animals, the lesions were found to have an area of Evans blue dye staining, but lacked discrete areas of necrosis and hemorrhage. Conclusion: These results suggest that the lazaroid U74389G protects the normal brain from radiation injury produced by stereotactic radiosurgery

  9. Long-term effects of whole brain radiation on intellectual function in children with medulloblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Uozumi, Akimasa; Okimura, Yoshitaka; Ohsato, Katsunobu; Yamaura, Akira; Hasegawa, Keiko (Chiba Univ. (Japan). School of Medicine)

    1992-10-01

    Neuropsychological tests were administered to four children 4 to 10 years after treatment of medulloblastoma with surgery, radiation, and natural alpha-interferon. The age at the time of treatment ranged from 2 years and 4 months to 11 years. The radiation doses were 26-34 Gy to the whole brain, 48-52 Gy to the posterior fossa and 26-34 Gy to the whole spine. Uneventful follow-up periods ranged from 4 years and 8 months to 10 years and 6 months. At present they attend regular classes at local schools. The neuropsychological tests used were: Wechsler Intelligence Scale for Children-Revised (WISC-R), Frostig developmental test of visual perception and Uchida-Kraepelin psychometric test. The WISC-R showed a marked decrease of full-scale IQ in two of the four children (scores of 72 and 73). Their performance IQ scores were significantly lower than their verbal scores. This may reflect less ability to manage visual and spatial information than verbal information. The other two patients had full-scale IQ scores of 91 and 92 (within the normal range). The test of visual perception showed decreased ability in the three patients who were younger than 8 years, of age at the time of treatment but normal ability in the child who had been treated at 11 years of age. The Uchida-Kraepelin test showed reduced amounts of work accomplished and poor learning ability in all four patients. These findings suggest that intellectual function in children with medulloblastoma is affected by the failure of visual perception to develop normally because of whole brain radiation at an early age and that their problem is aggravated by secondary learning difficulties. It is necessary to provide these patients with individual learning programs based on the results of neuropsychological evaluations. (author).

  10. A benchmark analysis of radiation flux distribution for Boron Neutron Capture Therapy of canine brain tumors

    International Nuclear Information System (INIS)

    Moran, J.M.

    1992-02-01

    Calculations of radiation flux and dose distributions for Boron Neutron Capture Therapy (BNCT) of brain tumors are typically performed using sophisticated three-dimensional analytical models based on either a homogeneous approximation or a simplified few-region approximation to the actual highly-heterogeneous geometry of the irradiation volume. Such models should be validated by comparison with calculations using detailed models in which all significant macroscopic tissue heterogeneities and geometric structures are explicitly represented as faithfully as possible. This work describes a validation exercise for BNCT of canine brain tumors. Geometric measurements of the canine anatomical structures of interest for this work were performed by dissecting and examining two essentially identical Labrador Retriever heads. Chemical analyses of various tissue samples taken during the dissections were conducted to obtain measurements of elemental compositions for tissues of interest. The resulting geometry and tissue composition data were then used to construct a detailed heterogeneous calculational model of the Labrador Retriever head. Calculations of three-dimensional radiation flux distributions pertinent to BNCT were performed for the model using the TORT discrete-ordinates radiation transport code. The calculations were repeated for a corresponding volume-weighted homogeneous tissue model. Comparison of the results showed that the peak neutron and photon flux magnitudes were quite similar for the two models (within 5%), but that the spatial flux profiles were shifted in the heterogeneous model such that the fluxes in some locations away from the peak differed from the corresponding fluxes in the homogeneous model by as much as 10-20%. Differences of this magnitude can be therapeutically significant, emphasizing the need for proper validation of simplified treatment planning models

  11. Brain Malformations

    Science.gov (United States)

    Most brain malformations begin long before a baby is born. Something damages the developing nervous system or causes it ... medicines, infections, or radiation during pregnancy interferes with brain development. Parts of the brain may be missing, ...

  12. Sense and antisense transcripts of the developmentally regulated murine hsp70.2 gene are expressed in distinct and only partially overlapping areas in the adult brain

    Science.gov (United States)

    Murashov, A. K.; Wolgemuth, D. J.

    1996-01-01

    We have examined the spatial pattern of expression of a member of the hsp70 gene family, hsp70.2, in the mouse central nervous system. Surprisingly, RNA blot analysis and in situ hybridization revealed abundant expression of an 'antisense' hsp70.2 transcript in several areas of adult mouse brain. Two different transcripts recognized by sense and antisense riboprobes for the hsp70.2 gene were expressed in distinct and only partially overlapping neuronal populations. RNA blot analysis revealed low levels of the 2.7 kb transcript of hsp70.2 in several areas of the brain, with highest signal in the hippocampus. Abundant expression of a slightly larger (approximately 2.8 kb) 'antisense' transcript was detected in several brain regions, notably in the brainstem, cerebellum, mesencephalic tectum, thalamus, cortex, and hippocampus. In situ hybridization revealed that the sense and antisense transcripts were both predominantly neuronal and localized to the same cell types in the granular layer of the cerebellum, trapezoid nucleus of the superior olivary complex, locus coeruleus and hippocampus. The hsp70.2 antisense transcripts were particularly abundant in the frontal cortex, dentate gyrus, subthalamic nucleus, zona incerta, superior and inferior colliculi, central gray, brainstem, and cerebellar Purkinje cells. Our findings have revealed a distinct cellular and spatial localization of both sense and antisense transcripts, demonstrating a new level of complexity in the function of the heat shock genes.

  13. Radiation brain dose to vascular surgeons during fluoroscopically guided interventions is not effectively reduced by wearing lead equivalent surgical caps.

    Science.gov (United States)

    Kirkwood, Melissa L; Arbique, Gary M; Guild, Jeffrey B; Zeng, Katie; Xi, Yin; Rectenwald, John; Anderson, Jon A; Timaran, Carlos

    2018-03-12

    Radiation to the interventionalist's brain during fluoroscopically guided interventions (FGIs) may increase the incidence of cerebral neoplasms. Lead equivalent surgical caps claim to reduce radiation brain doses by 50% to 95%. We sought to determine the efficacy of the RADPAD (Worldwide Innovations & Technologies, Lenexa, Kan) No Brainer surgical cap (0.06 mm lead equivalent at 90 kVp) in reducing radiation dose to the surgeon's and trainee's head during FGIs and to a phantom to determine relative brain dose reductions. Optically stimulated, luminescent nanoDot detectors (Landauer, Glenwood, Ill) inside and outside of the cap at the left temporal position were used to measure cap attenuation during FGIs. To check relative brain doses, nanoDot detectors were placed in 15 positions within an anthropomorphic head phantom (ATOM model 701; CIRS, Norfolk, Va). The phantom was positioned to represent a primary operator performing femoral access. Fluorography was performed on a plastic scatter phantom at 80 kVp for an exposure of 5 Gy reference air kerma with or without the hat. For each brain location, the percentage dose reduction with the hat was calculated. Means and standard errors were calculated using a pooled linear mixed model with repeated measurements. Anatomically similar locations were combined into five groups: upper brain, upper skull, midbrain, eyes, and left temporal position. This was a prospective, single-center study that included 29 endovascular aortic aneurysm procedures. The average procedure reference air kerma was 2.6 Gy. The hat attenuation at the temporal position for the attending physician and fellow was 60% ± 20% and 33% ± 36%, respectively. The equivalent phantom measurements demonstrated an attenuation of 71% ± 2.0% (P < .0001). In the interior phantom locations, attenuation was statistically significant for the skull (6% ± 1.4%) and upper brain (7.2% ± 1.0%; P < .0001) but not for the middle brain (1.4% ± 1.0%; P = .15

  14. 3D quantification of brain microvessels exposed to heavy particle radiation

    International Nuclear Information System (INIS)

    Hintermueller, C; Stampanoni, M; Coats, J S; Obenaus, A; Nelson, G; Krucker, T

    2009-01-01

    Space radiation with high energy particles and cosmic rays presents a significant hazard to spaceflight crews. Recent reviews of the health risk to astronauts from ionizing radiation concluded to establish a level of risk which may indicate the possible performance decrements and decreased latency of late dysfunction syndromes (LDS) of the brain. A hierarchical imaging approach developed at ETH Zuerich and PSI, which relies on synchrotron based X-ray Tomographic Microscopy (SRXTM), was used to visualize and analyze 3D vascular structures down to the capillary level in their precise anatomical context. Various morphological parameters, such as overall vessel volume, vessel thickness and spacing, are extracted to characterize the vascular structure within a region of interest. For a first quantification of the effect of high energy particles on the vasculature we scanned a set of 6 animals, all of same age. The animals were irradiated with 1 Gy, 2 Gy and 4 Gy of 600MeV 56 Fe heavy particles simulating the space radiation environment. We found that with increasing dose the diameter of vessels and the overall vessel volume are decreased whereas the vessel spacing is increased. As these parameters reflect blood flow in three-dimensional space they can be used as indicators for the degree of vascular efficiency which can have an impact on the function and development of lung tissue or tumors.

  15. Ionizing radiation action of transport systems of Na+ and K+ of neutronal membranes. Potassium ions reaccumulation with brain slices

    International Nuclear Information System (INIS)

    Dvoretsky, A.I.; Shainskaya, A.M.; Ananyeva, T.V.; Kulikova, I.A.

    1990-01-01

    The biological effect of ionizing radiation (IR) on the Na,K pump of the surviving brain cortex slices was investigated. It was shown that IR leads to marked disturbances in the Na,K pump activity and causes essential phasic changes in potassium ion reaccumulation by brain slices in different time after exposure. The possibility of modelling the radiation effect with the help of phospholipase A2 and decylenic acid was shown. The mechanisms of the functional disturbance of Na-K pump of nerve cells after irradiation are under discussion. (author)

  16. Effect of lymphokine-activated killer cells with or without radiation therapy against malignant brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Kunio; Kamezaki, Takao; Shibata, Yasushi; Tsunoda, Takashi; Meguro, Kotoo; Nose, Tadao [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine

    1995-01-01

    The use of autologous lymphokine-activated killer (LAK) cells to treat malignant brain tumors was evaluated in 10 patients, one with metastatic malignant melanoma and nine with malignant glioma. LAK cells were obtained by culturing autologous peripheral blood lymphocytes with human recombinant interleukin-2 (rIL-2) for 7-28 days. All patients underwent surgery to remove as much tumor as possible and an Ommaya reservoir was implaced in the tumor cavity. Two of the 10 patients had received radiotherapy elsewhere, so were treated with LAK cells alone. Eight patients were treated with a combination of LAK cells and radiotherapy, using 1.8-2.0 Gy fractions given five times a week with a total dosage between 54 and 65 Gy. LAK cells and rIL-2 were injected to the tumor cavity via the Ommaya reservoir once a week for inpatients and once a month for outpatients. The duration of the LAK therapy ranged from 3 to 23 months (mean 13.7 mos). Neuroimaging evaluation revealed two complete responses, three partial responses, four no changes, and one progressive disease. In one patient with pontine glioma, the Karnofsky performance score was raised from 20 to 60. There were no side effects after the injection of LAK cells and rIL-2. The results suggest low-dose LAK therapy is a useful and safe treatment modality for malignant brain tumors. (author).

  17. The Effect of 2.45 GHz Microwave Radiation on Brain Cell Apoptosis in Sprague Dawley Rats

    International Nuclear Information System (INIS)

    Wan Saffiey Wan Abdullah; Rozaimah Abdul Rahim; Zulkifli Yusof

    2016-01-01

    Microwave radiation is a part of non-ionizing electromagnetic radiations present in the environment and is now being perceived as health risks. The study was performed to investigate the effect of 2.45 GHz microwave radiation on brain cell apoptosis in Sprague Dawley rat. In the research done, 32 Sprague Dawley rat were used and divided into four groups; control group, G1 (1 month exposure), G2 (2 months exposure) and G3 (3 months exposure). The presence of apoptotic activity in control group was compared molecularly with exposed group through DNA ladder test. Each exposed group were irradiated in GTEM cell at frequency of 2.45 GHz located at RF/ MW laboratory. There was presence of necrotic instead of apoptotic activity in brain cell and increase in weight of Sprague Dawley rat. Therefore the effect of 2.45GHz microwave radiation shown no presence of apoptosis and increase in weight of Sprague Dawley rat. (author)

  18. Effect of Brain Tumor Presence During Radiation on Tissue Toxicity: Transcriptomic and Metabolic Changes.

    Science.gov (United States)

    Zawaski, Janice A; Sabek, Omaima M; Voicu, Horatiu; Eastwood Leung, Hon-Chiu; Gaber, M Waleed

    2017-11-15

    Radiation therapy (RT) causes functional and transcriptomic changes in the brain; however, most studies have been carried out in normal rodent brains. Here, the long-term effect of irradiation and tumor presence during radiation was investigated. Male Wistar rats ∼7 weeks old were divided into 3 groups: sham implant, RT+sham implant, and RT+tumor implant (C6 glioma). Hypofractionated irradiation (8 or 6 Gy/day for 5 days) was localized to a 1-cm strip of cranium starting 5 days after implantation, resulting in complete tumor regression and prolonged survival. Biopsy of tissue was performed in the implant area 65 days after implantation. RNA was hybridized to GeneChip Rat Exon 1.0 ST array. Data were analyzed using significant analysis of microarrays and ingenuity pathway analysis. 1 H magnetic resonance spectroscopy ( 1 H-MRS) imaging was performed in the implantation site 65 to 70 days after implantation using a 9.4 T Biospec magnetic resonance imaging scanner with a quadrature rat brain array. Immunohistochemical staining for astrogliosis, HMG-CoA synthase 2, γ-aminobutyric acid (GABA) and taurine was performed at ∼65 days after implantation. Eighty-four genes had a false discovery rate <3.5%. We compared RT+tumor implant with RT+sham implant animals. The tumor presence affected networks associated with cancer/cell morphology/tissue morphology. 1 H-MRS showed significant reduction in taurine levels (P<.04) at the implantation site in both groups. However, the RT+tumor group also showed significant increase in levels of neurotransmitter GABA (P=.02). Hippocampal taurine levels were only significantly reduced in the RT+tumor group (P=.03). HMG-CoA synthase 2, GABA and taurine levels were confirmed using staining. Glial fibrillary acidic protein staining demonstrated a significant increase in inflammation that was heightened in the RT+tumor group. Our data indicate that tumor presence during radiation significantly affects long-term functional

  19. Repeat Whole Brain Radiation Therapy with a Simultaneous Infield Boost: A Novel Technique for Reirradiation

    International Nuclear Information System (INIS)

    Hall, W.A.; Prabhu, R.S.; Crocker, I.R.; Dhabban, A.; Ogunleye, T.; Kandula, Sh.; Jiang, X.; Curran, W.J.; Shu, H.G.

    2014-01-01

    The treatment of patients who experience intracranial progression after whole brain radiation therapy (WBRT) is a clinical challenge. Novel radiation therapy delivery technologies are being applied with the objective of improving tumor and symptom control in these patients. The purpose of this study is to describe the clinical outcomes of the application of a novel technology to deliver repeat WBRT with volume modulated arc therapy (VMAT) and a simultaneous infield boost (WB-SIB) to gross disease. A total of 16 patients were initially treated with WBRT between 2000 and 2008 and then experienced intracranial progression, were treated using repeat WB-SIB, and were analyzed. The median dose for the first course of WBRT was 35 Gy (range: 30–50.4 Gy). Median time between the initial course of WBRT and repeat WB-SIB was 11.3 months. The median dose at reirradiation was 20 Gy to the whole brain with a median boost dose of 30 Gy to gross disease. A total of 2 patients demonstrated radiographic disease progression after treatment. The median overall survival (OS) time from initial diagnosis of brain metastases was 18.9 months (range: 7.1–66.6 (95% CI: 0.8–36.9)). The median OS time after initiation of reirradiation for all patients was 2.7 months (range: 0.46–14.46 (95% CI: 1.3–8.7)). Only 3 patients experienced CTCAE grade 3 fatigue. No other patients experienced any ≥ CTCAE grade 3 toxicity. This analysis reports the result of a novel RT delivery technique for the treatment of patients with recurrent brain metastases. Side effects were manageable and comparable to other conventional repeat WBRT series. Repeat WB-SIB using the VMAT RT delivery technology is feasible and appears to have acceptable short-term acute toxicity. These results may provide a foundation for further exploration of the WB-SIB technique for repeat WBRT in future prospective clinical trials.

  20. Inhibitory effect of magnesium sulfate on reaction of lipid hyperoxidation after radiation-induced acute brain injuries

    International Nuclear Information System (INIS)

    Wang Lili; Zhou Juying; Yu Zhiying; Qin Songbing; Xu Xiaoting; Li Li; Tu Yu

    2007-01-01

    Objective: To explore the protection of magnesium sulfate (MgSO 4 ) on radiation-induced acute brain injuries. Methods: 60 maturity Sprague-Dawley (SD) rats were randomly divided into 3 groups: blank control group, experimental control group and experimental-therapeutic group. The whole brain of SD rats of experimental control group and experimental-therapeutic group was irradiated to a dose of 20 Gy using 6 MeV electron. MgSO 4 was injected intraperitoneally into the rats of experimental-therapeutic group before and after irradiation for five times. At different time points ranging from the 1 d, 7 d, 14 d, 30 d after irradiation, the brain tissue were taken. The xanthine oxidase and colorimetric examination were used to measure the superoxide dismutase (SOD) and malonyldialdehyde (MDA) respectively in the rat brain respectively. Results: Compared with blank control group, the SOD in brain of experimental control group decreased significantly (P 4 used in early stage can inhibit the lipid peroxidation after radiation-induced acute brain injuries and alleviate the damage induced by free radicals to brain tissue. (authors)

  1. Prognostic factors derived from recursive partition analysis (RPA) of radiation therapy oncology group (RTOG) brain metastases trials applied to surgically resected and irradiated brain metastatic cases

    International Nuclear Information System (INIS)

    Agboola, Olusegun; Benoit, Brien; Cross, Peter; Silva, Vasco da; Esche, Bernd; Lesiuk, Howard; Gonsalves, Carol

    1998-01-01

    Purpose: (a) To identify the prognostic factors that determine survival after surgical resection and irradiation of tumors metastatic to brain. (b) To determine if the prognostic factors used in the recursive partition analysis (RPA) of brain metastases cases from Radiation Therapy Oncology Group (RTOG) studies into three distinct survival classes is applicable to surgically resected and irradiated patients. Method: The medical records of 125 patients who had surgical resection and radiotherapy for brain metastases from 1985 to 1997 were reviewed. The patients' disease and treatment related factors were analyzed to identify factors that independently determine survival after diagnosis of brain metastasis. The patients were also grouped into three classes using the RPA-derived prognostic parameters which are: age, performance status, state of the primary disease, and presence or absence of extracranial metastases. Class 1: patients ≤ 65 years of age, Karnofsky performance status (KPS) of ≥70, with controlled primary disease and no extracranial metastases; Class 3: patients with KPS < 70. Patients who do not qualify for Class 1 or 3 are grouped as Class 2. The survival of these patients was determined from the time of diagnosis of brain metastases to the time of death. Results: The median survival of the entire group was 9.5 months. The three classes of patients as grouped had median survivals of 14.8, 9.9, and 6.0 months respectively (p = 0.0002). Age of < 65 years, KPS of ≥ 70, controlled primary disease, absence of extracranial metastases, complete surgical resection of the brain lesion(s) were found to be independent prognostic factors for survival; the total dose of radiation was not. Conclusion: Based on the results of this study, the patients and disease characteristics have significant impact on the survival of patients with brain metastases treated with a combination of surgical resection and radiotherapy. These parameters could be used in selecting

  2. Treatment planning systems for external whole brain radiation therapy: With and without MLC (multi leaf collimator) optimization

    Science.gov (United States)

    Budiyono, T.; Budi, W. S.; Hidayanto, E.

    2016-03-01

    Radiation therapy for brain malignancy is done by giving a dose of radiation to a whole volume of the brain (WBRT) followed by a booster at the primary tumor with more advanced techniques. Two external radiation fields given from the right and left side. Because the shape of the head, there will be an unavoidable hotspot radiation dose of greater than 107%. This study aims to optimize planning of radiation therapy using field in field multi-leaf collimator technique. A study of 15 WBRT samples with CT slices is done by adding some segments of radiation in each field of radiation and delivering appropriate dose weighting using a TPS precise plan Elekta R 2.15. Results showed that this optimization a more homogeneous radiation on CTV target volume, lower dose in healthy tissue, and reduced hotspots in CTV target volume. Comparison results of field in field multi segmented MLC technique with standard conventional technique for WBRT are: higher average minimum dose (77.25% ± 0:47%) vs (60% ± 3:35%); lower average maximum dose (110.27% ± 0.26%) vs (114.53% ± 1.56%); lower hotspot volume (5.71% vs 27.43%); and lower dose on eye lenses (right eye: 9.52% vs 18.20%); (left eye: 8.60% vs 16.53%).

  3. Treatment planning systems for external whole brain radiation therapy: With and without MLC (multi leaf collimator) optimization

    International Nuclear Information System (INIS)

    Budiyono, T; Budi, W S; Hidayanto, E

    2016-01-01

    Radiation therapy for brain malignancy is done by giving a dose of radiation to a whole volume of the brain (WBRT) followed by a booster at the primary tumor with more advanced techniques. Two external radiation fields given from the right and left side. Because the shape of the head, there will be an unavoidable hotspot radiation dose of greater than 107%. This study aims to optimize planning of radiation therapy using field in field multi-leaf collimator technique. A study of 15 WBRT samples with CT slices is done by adding some segments of radiation in each field of radiation and delivering appropriate dose weighting using a TPS precise plan Elekta R 2.15. Results showed that this optimization a more homogeneous radiation on CTV target volume, lower dose in healthy tissue, and reduced hotspots in CTV target volume. Comparison results of field in field multi segmented MLC technique with standard conventional technique for WBRT are: higher average minimum dose (77.25% ± 0:47%) vs (60% ± 3:35%); lower average maximum dose (110.27% ± 0.26%) vs (114.53% ± 1.56%); lower hotspot volume (5.71% vs 27.43%); and lower dose on eye lenses (right eye: 9.52% vs 18.20%); (left eye: 8.60% vs 16.53%). (paper)

  4. Effects of dose and of partial body ionizing radiation on taste aversion learning in rats with lesions of the area postrema

    International Nuclear Information System (INIS)

    Rabin, B.M.; Hunt, W.A.; Lee, J.

    1984-01-01

    The effect of area postrema lesions on the acquisition of a conditioned taste aversion following partial body exposure to ionizing radiation was investigated in rats exposed to head-only irradiation at 100, 200 and 300 rad or to body-only irradiation at 100 and 200 rad. Following head-only irradiation area postrema lesions produced a significant attenuation of the radiation-induced taste aversion at all dose levels, although the rats still showed a significant reduction in sucrose preference. Following body-only exposure, area postrema lesions completely disrupted the acquisition of the conditioned taste aversion. The results are interpreted as indicating that: (a) the acquisition of a conditioned taste aversion following body-only exposure is mediated by the area postrema; and (b) taste aversion learning following radiation exposure to the head-only is mediated by both the area postrema and a mechanism which is independent of the area postrema

  5. The evaluation of lens absorbed dose according to the optimold for whole brain radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yong Mo; Park, Byoung Suk; Ahn, Jong Ho; Song, Ki Won [Dept. of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2014-06-15

    In the current whole brain Radiation Therapy, Optimold was used to immobilize the head. However, skin dose was increased about 22% due to the scattering radiation by the Optimold. Since the minimum dose causing cataracts was 2 Gy, it could be seen that the effects were large especially on the lens. Therefore, in the whole brain Radiation Therapy, it was to compare and to evaluate the lens absorbed dose according to the presence of Optimold in the eyeball part. In order to compare and to evaluate the lens absorbed dose according to the presence of Optimold in the eyeball part, the Optimold mask was made up to 5 mm bolus on the part of the eye lens in the human model phantom (Anderson Rando Phantom, USA). In the practice treatment, to measure the lens dose, the simulation therapy was processed by placing the GafChromic EBT3 film under bolus, and after the treatment plan was set up through the treatment planning system (Pinnacle, PHILIPS, USA), the treatments were measured repeatedly three times in the same way. After removing the Optimold mask in the eyeball part, it was measured in the same way as above. After scanning the film and measuring the dose by using the Digital Flatbed Scanner (Expression 10000XL, EPSON, USA), the doses were compared and evaluated according to the presence of Optimold mask in the eyeball part. When there was the Optimold mask in the eyeball part, it was measured at 10.2cGy ± 1.5 in the simulation therapy, and at 24.8cGy ± 2.7 in the treatment, and when the Optimold mask was removed in the eye part, it was measured at 12.9cGy ± 2.2 in the simulation therapy, and at 17.6cGy ± 1.5 in the treatment. In case of removing the Optimold mask in the eyeball part, the dose was increased approximately 3cGy in the simulation therapy and was reduced approximately 7cGy in the treatment in comparison to the case that the Optimold mask was not removed. During the whole treatment, since the lens absorbed dose was reduced about 27%, the chance to cause

  6. The evaluation of lens absorbed dose according to the optimold for whole brain radiation therapy

    International Nuclear Information System (INIS)

    Yang, Yong Mo; Park, Byoung Suk; Ahn, Jong Ho; Song, Ki Won

    2014-01-01

    In the current whole brain Radiation Therapy, Optimold was used to immobilize the head. However, skin dose was increased about 22% due to the scattering radiation by the Optimold. Since the minimum dose causing cataracts was 2 Gy, it could be seen that the effects were large especially on the lens. Therefore, in the whole brain Radiation Therapy, it was to compare and to evaluate the lens absorbed dose according to the presence of Optimold in the eyeball part. In order to compare and to evaluate the lens absorbed dose according to the presence of Optimold in the eyeball part, the Optimold mask was made up to 5 mm bolus on the part of the eye lens in the human model phantom (Anderson Rando Phantom, USA). In the practice treatment, to measure the lens dose, the simulation therapy was processed by placing the GafChromic EBT3 film under bolus, and after the treatment plan was set up through the treatment planning system (Pinnacle, PHILIPS, USA), the treatments were measured repeatedly three times in the same way. After removing the Optimold mask in the eyeball part, it was measured in the same way as above. After scanning the film and measuring the dose by using the Digital Flatbed Scanner (Expression 10000XL, EPSON, USA), the doses were compared and evaluated according to the presence of Optimold mask in the eyeball part. When there was the Optimold mask in the eyeball part, it was measured at 10.2cGy ± 1.5 in the simulation therapy, and at 24.8cGy ± 2.7 in the treatment, and when the Optimold mask was removed in the eye part, it was measured at 12.9cGy ± 2.2 in the simulation therapy, and at 17.6cGy ± 1.5 in the treatment. In case of removing the Optimold mask in the eyeball part, the dose was increased approximately 3cGy in the simulation therapy and was reduced approximately 7cGy in the treatment in comparison to the case that the Optimold mask was not removed. During the whole treatment, since the lens absorbed dose was reduced about 27%, the chance to cause

  7. Effects of GSM modulated radio-frequency electromagnetic radiation on permeability of blood-brain barrier in male & female rats.

    Science.gov (United States)

    Sırav, Bahriye; Seyhan, Nesrin

    2016-09-01

    With the increased use of mobile phones, their biological and health effects have become more important. Usage of mobile phones near the head increases the possibility of effects on brain tissue. This study was designed to investigate the possible effects of pulse modulated 900MHz and 1800MHz radio-frequency radiation on the permeability of blood-brain barrier of rats. Study was performed with 6 groups of young adult male and female wistar albino rats. The permeability of blood-brain barrier to intravenously injected evans blue dye was quantitatively examined for both control and radio-frequency radiarion exposed groups. For male groups; Evans blue content in the whole brain was found to be 0.08±0.01mg% in the control, 0.13±0.03mg% in 900MHz exposed and 0.26±0.05mg% in 1800MHz exposed animals. In both male radio-frequency radiation exposed groups, the permeability of blood-brain barrier found to be increased with respect to the controls (pradiation exposure was found more effective on the male animals (p0.01). However 900MHz pulse modulated radio-frequency exposure was found effective on the permeability of blood-brain barrier of female animals. Results have shown that 20min pulse modulated radio-frequency radiation exposure of 900MHz and 1800MHz induces an effect and increases the permeability of blood-brain barrier of male rats. For females, 900MHz was found effective and it could be concluded that this result may due to the physiological differences between female and male animals. The results of this study suggest that mobile phone radation could lead to increase the permeability of blood-brain barrier under non-thermal exposure levels. More studies are needed to demonstrate the mechanisms of that breakdown. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Naloxone-sensitive, haloperidol-sensitive, [3H](+)SKF-10047-binding protein partially purified from rat liver and rat brain membranes: an opioid/sigma receptor?

    Science.gov (United States)

    Tsao, L I; Su, T P

    1997-02-01

    A naloxone-sensitive, haloperidol-sensitive, [3H](+)SKF-10047-binding protein was partially purified from rat liver and rat brain membranes in an affinity chromatography originally designed to purify sigma receptors. Detergent-solubilized extracts from membranes were adsorbed to Sephadex G-25 resin containing an affinity ligand for sigma receptors: N-(2- 3,4-dichlorophenyl]ethyl)-N-(6-aminohexyl)-(2-[1-pyrrolidinyl]) ethylamine (DAPE). After eluting the resin with haloperidol, a protein that bound [3H](+)SKF-10047 was detected in the eluates. However, the protein was not the sigma receptor. [3H](+)SKF-10047 binding to the protein was inhibited by the following compounds in the order of decreasing potency: (+)pentazocine > (-) pentazocine > (+/-)cyclazocine > (-)morphine > (-)naloxone > haloperidol > (+)SKF-10047 > DADLE > (-)SKF-10047. Further, the prototypic sigma receptor ligands, such as 1,3-di-o-tolylguanidine (DTG), (+)3-PPP, and progesterone, bound poorly to the protein. Tryptic digestion and heat treatment of the affinity-purified protein abolished radioligand binding. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS/PAGE) of the partially-purified protein from the liver revealed a major diffuse band with a molecular mass of 31 kDa, a polypeptide of 65 kDa, and another polypeptide of > 97 kDa. This study demonstrates the existence of a novel protein in the rat liver and rat brain which binds opioids, benzomorphans, and haloperidol with namomolar affinity. The protein resembles the opioid/sigma receptor originally proposed by Martin et al. [(1976): J. Pharmacol. Exp. Ther., 197:517-532.]. A high degree of purification of this protein has been achieved in the present study.

  9. Nuclear medicine in the detection of radiation associated normal tissue damage of kidney, brain and salivary glands

    International Nuclear Information System (INIS)

    Liu Xiaomei; Li Dongxue; Pan Liping

    2005-01-01

    The radiation induced damage of kidney, brain and salivary glands is an important complicating disease after limit radiotherapy. The routine technology of nuclear medicine, such as tracing and imaging technique conduce to dose-effect calculations used in the planning of modern radiotherapy to three major organ systems and early detection of irradiation induced organ dysfunctions, as well as increased availability of radiotherapy. (authors)

  10. Anthocyanin-rich blueberry diets enhance protection of critical brain regions exposed to acute levels of 56Fe cosmic radiation

    Science.gov (United States)

    The protective effects of anthocyanin-rich blueberries on brain health are well documented and are particularly important under conditions of high oxidative stress which can lead to “accelerated aging”. One such scenario is exposure to space radiation, which consists of high-energy and -charge parti...

  11. Intra-arterial and intra-venous chemotherapy combined with radiation in the treatment of brain tumours

    International Nuclear Information System (INIS)

    Watne, K.

    1992-01-01

    The present investigations were undertaken to study the effect of combining different modalities of chemotherapy with radiation in post-operative treatment of brain tumours. The conclusions and clinical implication of the investigations are as follows: The combination of combined intra-arterial chemotherapy followed by radiation leads to an increased median survival with more long term survivors in patients with anaplastic astrocytomas and in patients older than 40 years with astrocytomas. In patients with glioblastoma multiforme, this modality of treatment do not improve median survival, but an increased number of long-term survivors may be seen. Patients younger than 40 years with astrocytomas do not benefit from this modality of treatment. A parallelism exists between sensitivity to chemotherapy and response to radiotherapy. Patients who will benefit from the treatment may be selected early, normally two months after treatment start. Combining intra-arterial chemotherapy and radiation does not lead to an increased incidence of adverse CNS reactions. Specific transient abnormalities in the brain may occur during the first year after treatment and may be misinterpreted as tumour recurrence. EEG may be valuable in predicting adverse CNS reactions following treatment. Nuclear brain scan may be of valuable in selecting the patients who are in danger of developing adverse CNS reactions. Intra-arterial chemotherapy does have an effect in patients with brain tumours who have recurrent tumour after radiation. The most important prognostic factors are age, corticosteroid dependency at treatment start, performance status, histology and frontal lobe location. 103 refs., 2 tabs

  12. CD44v6 regulates growth of brain tumor stem cells partially through the AKT-mediated pathway.

    Directory of Open Access Journals (Sweden)

    Mayumi Jijiwa

    Full Text Available Identification of stem cell-like brain tumor cells (brain tumor stem-like cells; BTSC has gained substantial attention by scientists and physicians. However, the mechanism of tumor initiation and proliferation is still poorly understood. CD44 is a cell surface protein linked to tumorigenesis in various cancers. In particular, one of its variant isoforms, CD44v6, is associated with several cancer types. To date its expression and function in BTSC is yet to be identified. Here, we demonstrate the presence and function of the variant form 6 of CD44 (CD44v6 in BTSC of a subset of glioblastoma multiforme (GBM. Patients with CD44(high GBM exhibited significantly poorer prognoses. Among various variant forms, CD44v6 was the only isoform that was detected in BTSC and its knockdown inhibited in vitro growth of BTSC from CD44(high GBM but not from CD44(low GBM. In contrast, this siRNA-mediated growth inhibition was not apparent in the matched GBM sample that does not possess stem-like properties. Stimulation with a CD44v6 ligand, osteopontin (OPN, increased expression of phosphorylated AKT in CD44(high GBM, but not in CD44(low GBM. Lastly, in a mouse spontaneous intracranial tumor model, CD44v6 was abundantly expressed by tumor precursors, in contrast to no detectable CD44v6 expression in normal neural precursors. Furthermore, overexpression of mouse CD44v6 or OPN, but not its dominant negative form, resulted in enhanced growth of the mouse tumor stem-like cells in vitro. Collectively, these data indicate that a subset of GBM expresses high CD44 in BTSC, and its growth may depend on CD44v6/AKT pathway.

  13. Identifying cochlear implant channels with poor electrode-neuron interfaces: electrically evoked auditory brain stem responses measured with the partial tripolar configuration.

    Science.gov (United States)

    Bierer, Julie Arenberg; Faulkner, Kathleen F; Tremblay, Kelly L

    2011-01-01

    The goal of this study was to compare cochlear implant behavioral measures and electrically evoked auditory brain stem responses (EABRs) obtained with a spatially focused electrode configuration. It has been shown previously that channels with high thresholds, when measured with the tripolar configuration, exhibit relatively broad psychophysical tuning curves. The elevated threshold and degraded spatial/spectral selectivity of such channels are consistent with a poor electrode-neuron interface, defined as suboptimal electrode placement or reduced nerve survival. However, the psychophysical methods required to obtain these data are time intensive and may not be practical during a clinical mapping session, especially for young children. Here, we have extended the previous investigation to determine whether a physiological approach could provide a similar assessment of channel functionality. We hypothesized that, in accordance with the perceptual measures, higher EABR thresholds would correlate with steeper EABR amplitude growth functions, reflecting a degraded electrode-neuron interface. Data were collected from six cochlear implant listeners implanted with the HiRes 90k cochlear implant (Advanced Bionics). Single-channel thresholds and most comfortable listening levels were obtained for stimuli that varied in presumed electrical field size by using the partial tripolar configuration, for which a fraction of current (σ) from a center active electrode returns through two neighboring electrodes and the remainder through a distant indifferent electrode. EABRs were obtained in each subject for the two channels having the highest and lowest tripolar (σ = 1 or 0.9) behavioral threshold. Evoked potentials were measured with both the monopolar (σ = 0) and a more focused partial tripolar (σ ≥ 0.50) configuration. Consistent with previous studies, EABR thresholds were highly and positively correlated with behavioral thresholds obtained with both the monopolar and partial

  14. How to identify partial exposures to ionizing radiation? Proposal for a cytogenetic method; Como identificar exposicoes parciais as radiacoes ionizantes? Proposta de um metodo citogenetico

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, T.S.; Silva, E.B.; Pinto, M.M.P.L.; Amaral, A., E-mail: thiagosalazar@hotmail.com [Universidade Federal de Pernambuco (LAMBDA/UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear. Lab. de Modelagem e Biodosimetria Aplicada; Lloyd, David [Health Protection Agency, Oxford (United Kingdom). Radiation Protection Division

    2013-08-15

    In cases of radiological incidents or in occupational exposures to ionizing radiation, the majority of exposures are not related to the total body, but only partial. In this context, if the cytogenetic dosimetry is performed, there will be an underestimation of the absorbed dose due to the dilution of irradiated cells with non-irradiated cells. Considering the norms of NR 32 - Safety and Health in the Work of Health Service - which recommends cytogenetic dosimetry in the investigation of accidental exposures to ionizing radiations, it is necessary to develop of a tool to provide a better identification of partial exposures. With this aim, a partial body exposure was simulated by mixing, in vitro, 70% of blood irradiated with 4 Gy of X-rays with 30% of unirradiated blood from the same healthy donor. Aliquots of this mixture were cultured for 48 and 72 hours. Prolonging the time of cell culture from 48 to 72 hours produced no significant change in the yield of dicentrics. However, when only M1 (first division cells) were analyzed, the frequency of dicentrics per cell was increased. Prolonging the time of cell culture allowed cells in mitotic delay by irradiation to reach metaphase, and thus provides enough time for the damage to be visualized. The results of this research present the proposed method as an important tool in the investigation of exposed individuals, allowing associating the cytogenetic analysis with the real percentage of irradiated cells, contributing significantly for the decision making in terms of occupational health. (author)

  15. Overall Survival After Whole-Brain Radiation Therapy for Intracerebral Metastases from Testicular Cancer.

    Science.gov (United States)

    Rades, Dirk; Dziggel, Liesa; Veninga, Theo; Bajrovic, Amira; Schild, Steven E

    2016-09-01

    To identify predictors and develop a score for overall survival of patients with intracerebral metastasis from testicular cancer. Whole-brain radiation therapy program, age, Karnofsky performance score (KPS), number of intracerebral metastases, number of other metastatic sites and time between testicular cancer diagnosis and radiation therapy were analyzed for their association with overall survival in eight patients. KPS of 80-90% was significantly associated with better overall survival (p=0.006), one or no other metastatic sites showed a trend for a better outcome (p=0.10). The following scores were assigned: KPS 60-70%=0 points, KPS 80-90%=1 point, ≥2 other metastatic sites=0 points, 0-1 other metastatic sites=1 point. Two groups, with 0 and with 1-2 points, were formed. Overall survival rates were 33% vs. 100% at 6 months and 0% vs. 100% at 12 months (p=0.006), respectively. A simple instrument enabling physicians to judge the overall survival of patients with intracerebral metastasis from testicular cancer is provided. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  16. Late radiation damage in bone, bone marrow and brain vasculature, with particular emphasis upon fractionation models

    International Nuclear Information System (INIS)

    Pitkaenen, Maunu.

    1986-04-01

    X-ray induced changes in rat and human bone and bone marrow vasculature and in rat brain vasculature were measured as a function of time after irradiation and absorbed dose. The absorbed dose in the organ varied from 5 to 25 Gy for single dose irradiations and from 19 to 58 Gy for fractionated irradiations.The number of fractions varied from 3 to 10 for the rats and from 12 to 25 for the human. Blood flow changes were measured using an ''1''2''5I antipyrine or ''8''6RbCl extraction technique. The red blood cell (RBC) volume was examined by ''5''1Cr labelled red cells. Different fractionation models have been compared. Radiation induced reduction of bone and bone marrow blood flow were both time and dose dependent. Reduced blood flow 3 months after irradiation would seem to be an important factor in the subsequent atrophy of bones. With a single dose of 10 Gy the bone marrow blood flow returned to the control level by 7 months after irradiation. In the irradiated bone the RBC volume was about same as that in the control side but in bone marrow the reduction was from 32 to 59%. The dose levels predicted by the nominal standard dose (NSD) formula produced about the same damage to the rat femur seven months after irradiation when the extraction of ''8''6Rb chloride and the dry weight were concerned as the end points. However, the results suggest that the NSB formula underestimates the late radiation damage in bone marrow when a small number of large fractions are used. In the irradiated brains of the rats the blood flow was on average 20.4% higher compared to that in the control group. There was no significant difference in brain blood flow between different fractionation schemes. The value of 0.42 for the exponent of N corresponds to the average value for central nervous system tolerance in the literature. The model used may be sufficiently accurate for clinical work provided the treatment schemes used do not depart too radically from standard practice

  17. Infant Brain Tumors: Incidence, Survival, and the Role of Radiation Based on Surveillance, Epidemiology, and End Results (SEER) Data

    International Nuclear Information System (INIS)

    Bishop, Andrew J.; McDonald, Mark W.; Chang, Andrew L.; Esiashvili, Natia

    2012-01-01

    Purpose: To evaluate the incidence of infant brain tumors and survival outcomes by disease and treatment variables. Methods and Materials: The Surveillance, Epidemiology, and End Results (SEER) Program November 2008 submission database provided age-adjusted incidence rates and individual case information for primary brain tumors diagnosed between 1973 and 2006 in infants less than 12 months of age. Results: Between 1973 and 1986, the incidence of infant brain tumors increased from 16 to 40 cases per million (CPM), and from 1986 to 2006, the annual incidence rate averaged 35 CPM. Leading histologies by annual incidence in CPM were gliomas (13.8), medulloblastoma and primitive neuroectodermal tumors (6.6), and ependymomas (3.6). The annual incidence was higher in whites than in blacks (35.0 vs. 21.3 CPM). Infants with low-grade gliomas had the highest observed survival, and those with atypical teratoid rhabdoid tumors (ATRTs) or primary rhabdoid tumors of the brain had the lowest. Between 1979 and 1993, the annual rate of cases treated with radiation within the first 4 months from diagnosis declined from 20.5 CPM to <2 CPM. For infants with medulloblastoma, desmoplastic histology and treatment with both surgery and upfront radiation were associated with improved survival, but on multivariate regression, only combined surgery and radiation remained associated with improved survival, with a hazard ratio for death of 0.17 compared with surgery alone (p = 0.005). For ATRTs, those treated with surgery and upfront radiation had a 12-month survival of 100% compared with 24.4% for those treated with surgery alone (p = 0.016). For ependymomas survival was higher in patients treated in more recent decades (p = 0.001). Conclusion: The incidence of infant brain tumors has been stable since 1986. Survival outcomes varied markedly by histology. For infants with medulloblastoma and ATRTs, improved survival was observed in patients treated with both surgery and early radiation

  18. The role of computed tomography in evaluation of a white matter edema during postoperative brain radiation therapy

    International Nuclear Information System (INIS)

    Thalacker, U.; Somogyi, A.; Nemeth, G.; Liszka, G.

    1998-01-01

    The aim of our study was to determine on CT whether a relation exists between a radiation induced brain edema, treated with diuretics and its corresponding Houndsfield Units (HU). Seventy-five patients (age 20 to 65 years), suffering from headaches but without hypertension, brain tumors or cerebral arteriosclerosis were examined as a reference group. The second group consisted of 20 patients with brain tumors, which underwent brain surgery. HU of the white matter were measured before radiation and after 10, 20, 30, 40 and 50 Gy. The third group consisted of 64 patients with brain tumors, that underwent postsurgical radiation therapy. Prior to radiation therapy 40 mg furosemide per os were given. CT-examinations, intensified diuretic therapy and follow-up examinations were performed as in group 2. If, despite therapy, the HU decreased, infusion of mannites was added. The second and third group of patients recieved radiation therapy with telecobalt and/or a linear accelerator (6 and 9 MeV X-ray). In the first group white matter density was >30 HU. In the second group white matter density was between 25 and 29 HU prior to diuretic therapy. Under 25 HU a continuous headache, vertigo and confusion ensued. Diuretic therapy was intensified until the measured values reached 25 to 29 HU. Forty-seven of 64 patients in the third group had 25 to 29 HU prior to radiation therapy. Despite prophylactic diuretic therapy in 28 cases density decreased to 20 to 24 HU. Improvement was achived with an additional glycerine per os. The measured values reached again 25 to 29 HU. In 1 case the values dropped under 20 HU. Additional mannite infusion was necessary. In 17 to 64 patients white matter density was >30 HU prior to radiation therapy, dropping to 25 to 29 HU during radiation. Prophylactic diuretic administration kept the values in this range. A correlation between age of the patient, radiation source, total dose, tumor histology and degree of change in HU was not found. (orig

  19. The influence of high-intensity radiation on the functional status of monkey brain. Postirradiation changes in the bioelectric activity of the brain

    International Nuclear Information System (INIS)

    Legeza, V.I.; Turlakov, Yu.S.

    1991-01-01

    In experiments with Macaca fascicularis it has found that changes in the total bioelectric activity of the brain within the EEG range that occur during the first 60 min following whole-bofy irradiation with a dose of 45 Gy (6.6 Gy/s) are interrelated with the dynamica of nervous and psychic activity of the exposed animals, exhibit a definite stereotype of their development (disorganization of rhythms: generalized synchronization of biopotentials; and development of synchronous processes), and coincide in time with the main stages of the development of the clinical picture of the acute postirradiation period (noncoordinated stimulation, sopor or coma, and partial recovery)

  20. Abnormalities in Dynamic Brain Activity Caused by Mild Traumatic Brain Injury Are Partially Rescued by the Cannabinoid Type-2 Receptor Inverse Agonist SMM-189.

    Science.gov (United States)

    Liu, Yu; McAfee, Samuel S; Guley, Natalie M; Del Mar, Nobel; Bu, Wei; Heldt, Scott A; Honig, Marcia G; Moore, Bob M; Reiner, Anton; Heck, Detlef H

    2017-01-01

    Mild traumatic brain injury (mTBI) can cause severe long-term cognitive and emotional deficits, including impaired memory, depression, and persevering fear, but the neuropathological basis of these deficits is uncertain. As medial prefrontal cortex (mPFC) and hippocampus play important roles in memory and emotion, we used multi-site, multi-electrode recordings of oscillatory neuronal activity in local field potentials (LFPs) in awake, head-fixed mice to determine if the functioning of these regions was abnormal after mTBI, using a closed-skull focal cranial blast model. We evaluated mPFC, hippocampus CA1, and primary somatosensory/visual cortical areas (S1/V1). Although mTBI did not alter the power of oscillations, it did cause increased coherence of θ (4-10 Hz) and β (10-30 Hz) oscillations within mPFC and S1/V1, reduced CA1 sharp-wave ripple (SWR)-evoked LFP activity in mPFC, downshifted SWR frequencies in CA1, and enhanced θ-γ phase-amplitude coupling (PAC) within mPFC. These abnormalities might be linked to the impaired memory, depression, and persevering fear seen after mTBI. Treatment with the cannabinoid type-2 (CB2) receptor inverse agonist SMM-189 has been shown to mitigate functional deficits and neuronal injury after mTBI in mice. We found that SMM-189 also reversed most of the observed neurophysiological abnormalities. This neurophysiological rescue is likely to stem from the previously reported reduction in neuron loss and/or the preservation of neuronal function and connectivity resulting from SMM-189 treatment, which appears to stem from the biasing of microglia from the proinflammatory M1 state to the prohealing M2 state by SMM-189.

  1. Predictors for long-term survival free from whole brain radiation therapy in patients treated with radiosurgery for limited brain metastases

    Directory of Open Access Journals (Sweden)

    Daniel eGorovets

    2015-05-01

    Full Text Available Purpose: To identify predictors for prolonged survival free from salvage whole brain radiation therapy (WBRT in patients with brain metastases treated with stereotactic radiosurgery (SRS as their initial radiotherapy approach. Material and Methods: Patients with brain metastases treated with SRS from 2001-2013 at our institution were identified. SRS without WBRT was typically offered to patients with 1-4 brain metastases, Karnofsky Performance Status ≥70, and life expectancy ≥3 mo. Three hundred and eight patients met inclusion criteria for analysis. Medical records were reviewed for patient, disease, and treatment information. Two comparison groups were identified: those with ≥1-yr WBRT-free survival (N=104, and those who died or required salvage WBRT within 3 mo of SRS (N=56. Differences between these groups were assessed by univariate and multivariate analyses.Results: Median survival for all patients was 11 mo. Among patients with ≥1-yr WBRT-free survival, median survival was 33 mo [12-107 mo] with only 21% requiring salvage WBRT. Factors significantly associated with prolonged WBRT-free survival on univariate analysis (p<0.05 included younger age, asymptomatic presentation, RTOG RPA class I, fewer brain metastases, surgical resection, breast primary, new or controlled primary, absence of extracranial metastatic disease, and oligometastatic disease burden (≤5 metastatic lesions. After controlling for covariates, asymptomatic presentation, breast primary, single brain metastasis, absence of extracranial metastases, and oligometastatic disease burden remained independent predictors for favorable WBRT-free survival.Conclusions: A subset of patients with brain metastases can achieve long-term survival after upfront SRS without the need for salvage WBRT. Predictors identified in this study can help select patients that might benefit most from a treatment strategy of SRS alone.

  2. A randomised trial to compare cognitive outcome after gamma knife radiosurgery versus whole brain radiation therapy in patients with multiple brain metastases: research protocol CAR-study B.

    Science.gov (United States)

    Schimmel, Wietske C M; Verhaak, Eline; Hanssens, Patrick E J; Gehring, Karin; Sitskoorn, Margriet M

    2018-02-21

    Gamma Knife radiosurgery (GKRS) is increasingly applied in patients with multiple brain metastases and is expected to have less adverse effects in cognitive functioning than whole brain radiation therapy (WBRT). Effective treatment with the least negative cognitive side effects is increasingly becoming important, as more patients with brain metastases live longer due to more and better systemic treatment options. There are no published randomized trials yet directly comparing GKRS to WBRT in patients with multiple brain metastases that include objective neuropsychological testing. CAR-Study B is a prospective randomised trial comparing cognitive outcome after GKRS or WBRT in adult patients with 11-20 newly diagnosed brain metastases on a contrast-enhanced MRI-scan, KPS ≥70 and life expectancy of at least 3 months. Randomisation by the method of minimization, is stratified by the cumulative tumour volume in the brain, systemic treatment, KPS, histology, baseline cognitive functioning and age. The primary endpoint is the between-group difference in the percentage of patients with significant memory decline at 3 months. Secondary endpoints include overall survival, local control, development of new brain metastases, cognitive functioning over time, quality of life, depression, anxiety and fatigue. Cognitive functioning is assessed by a standardised neuropsychological test battery. Assessments (cognitive testing, questionnaires and MRI-scans) are scheduled at baseline and at 3, 6, 9, 12 and 15 months after treatment. Knowledge gained from this trial may be used to inform individual patients with BM more precisely about the cognitive effects they can expect from treatment, and to assist both doctors and patients in making (shared) individual treatment decisions. This trial is currently recruiting. Target accrual: 23 patients at 3-months follow-up in both groups. The Netherlands Trials Register number NTR5463. ClinicalTrials.gov registration number NCT02953717

  3. Optimization of a partially non-magnetic primary radiation shielding for the triple-axis spectrometer PANDA at the Munich high-flux reactor FRM-II

    CERN Document Server

    Pyka, N M; Rogov, A

    2002-01-01

    Monte Carlo simulations have been used to optimize the monochromator shielding of the polarized cold-neutron triple-axis spectrometer PANDA at the Munich high-flux reactor FRM-II. By using the Monte Carlo program MCNP-4B, the density of the total spectrum of incoming neutrons and gamma radiation from the beam tube SR-2 has been determined during the three-dimensional diffusion process in different types of heavy concrete and other absorbing material. Special attention has been paid to build a compact and highly efficient shielding, partially non-magnetic, with a total biological radiation dose of less than 10 mu Sv/h at its outsides. Especially considered was the construction of an albedo reducer, which serves to reduce the background in the experiment outside the shielding. (orig.)

  4. Impact of partial versus whole breast radiation therapy on fatigue, perceived stress, quality of life and natural killer cell activity in women with breast cancer.

    Science.gov (United States)

    Albuquerque, Kevin; Tell, Dina; Lobo, Philip; Millbrandt, Linda; Mathews, Herbert L; Janusek, Linda Witek

    2012-06-18

    This pilot study used a prospective longitudinal design to compare the effect of adjuvant whole breast radiation therapy (WBRT) versus partial breast radiation therapy (PBRT) on fatigue, perceived stress, quality of life and natural killer cell activity (NKCA) in women receiving radiation after breast cancer surgery. Women (N = 30) with early-stage breast cancer received either PBRT, Mammosite brachytherapy at dose of 34 Gy 10 fractions/5 days, (N = 15) or WBRT, 3-D conformal techniques at dose of 50 Gy +10 Gy Boost/30 fractions, (N = 15). Treatment was determined by the attending oncologist after discussion with the patient and the choice was based on tumor stage and clinical need. Women were assessed prior to initiation of radiation therapy and twice after completion of radiation therapy. At each assessment, blood was obtained for determination of NKCA and the following instruments were administered: Perceived Stress Scale (PSS), Functional Assessment of Cancer Therapy-Fatigue (FACT-F), and Functional Assessment of Cancer Therapy-General (FACT-G). Hierarchical linear modeling (HLM) was used to evaluate group differences in initial outcomes and change in outcomes over time. Fatigue (FACT-F) levels, which were similar prior to radiation therapy, demonstrated a significant difference in trajectory. Women who received PBRT reported progressively lower fatigue; conversely fatigue worsened over time for women who received WBRT. No difference in perceived stress was observed between women who received PBRT or WBRT. Both groups of women reported similar levels of quality of life (FACT-G) prior to initiation of radiation therapy. However, HLM analysis revealed significant group differences in the trajectory of quality of life, such that women receiving PBRT exhibited a linear increase in quality of life over time after completion of radiation therapy; whereas women receiving WBRT showed a decreasing trajectory. NKCA was also similar between therapy

  5. Predictive Risk of Radiation Induced Cerebral Necrosis in Pediatric Brain Cancer Patients after VMAT Versus Proton Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Freund, Derek; Zhang, Rui, E-mail: rzhang@marybird.com [Department of Radiation Oncology, Mary Bird Perkins Cancer Center, 4950 Essen Ln., Baton Rouge, LA 70809 (United States); Department of Physics and Astronomy, Louisiana State University, Nicholson Hall, Tower Dr., Baton Rouge, LA 70810 (United States); Sanders, Mary [Department of Radiation Oncology, Mary Bird Perkins Cancer Center, 4950 Essen Ln., Baton Rouge, LA 70809 (United States); Newhauser, Wayne [Department of Radiation Oncology, Mary Bird Perkins Cancer Center, 4950 Essen Ln., Baton Rouge, LA 70809 (United States); Department of Physics and Astronomy, Louisiana State University, Nicholson Hall, Tower Dr., Baton Rouge, LA 70810 (United States)

    2015-04-13

    Cancer of the brain and central nervous system (CNS) is the second most common of all pediatric cancers. Treatment of many of these cancers includes radiation therapy of which radiation induced cerebral necrosis (RICN) can be a severe and potentially devastating side effect. Risk factors for RICN include brain volume irradiated, the dose given per fraction and total dose. Thirteen pediatric patients were selected for this study to determine the difference in predicted risk of RICN when treating with volumetric modulated arc therapy (VMAT) compared to passively scattered proton therapy (PSPT) and intensity modulated proton therapy (IMPT). Plans were compared on the basis of dosimetric endpoints in the planned treatment volume (PTV) and brain and a radiobiological endpoint of RICN calculated using the Lyman-Kutcher-Burman probit model. Uncertainty tests were performed to determine if the predicted risk of necrosis was sensitive to positional errors, proton range errors and selection of risk models. Both PSPT and IMPT plans resulted in a significant increase in the maximum dose to the brain, a significant reduction in the total brain volume irradiated to low doses, and a significant lower predicted risk of necrosis compared with the VMAT plans. The findings of this study were upheld by the uncertainty analysis.

  6. Predictive Risk of Radiation Induced Cerebral Necrosis in Pediatric Brain Cancer Patients after VMAT Versus Proton Therapy

    Directory of Open Access Journals (Sweden)

    Derek Freund

    2015-04-01

    Full Text Available Cancer of the brain and central nervous system (CNS is the second most common of all pediatric cancers. Treatment of many of these cancers includes radiation therapy of which radiation induced cerebral necrosis (RICN can be a severe and potentially devastating side effect. Risk factors for RICN include brain volume irradiated, the dose given per fraction and total dose. Thirteen pediatric patients were selected for this study to determine the difference in predicted risk of RICN when treating with volumetric modulated arc therapy (VMAT compared to passively scattered proton therapy (PSPT and intensity modulated proton therapy (IMPT. Plans were compared on the basis of dosimetric endpoints in the planned treatment volume (PTV and brain and a radiobiological endpoint of RICN calculated using the Lyman-Kutcher-Burman probit model. Uncertainty tests were performed to determine if the predicted risk of necrosis was sensitive to positional errors, proton range errors and selection of risk models. Both PSPT and IMPT plans resulted in a significant increase in the maximum dose to the brain, a significant reduction in the total brain volume irradiated to low doses, and a significant lower predicted risk of necrosis compared with the VMAT plans. The findings of this study were upheld by the uncertainty analysis.

  7. Infant brain tumors: incidence, survival, and the role of radiation based on Surveillance, Epidemiology, and End Results (SEER) Data.

    Science.gov (United States)

    Bishop, Andrew J; McDonald, Mark W; Chang, Andrew L; Esiashvili, Natia

    2012-01-01

    To evaluate the incidence of infant brain tumors and survival outcomes by disease and treatment variables. The Surveillance, Epidemiology, and End Results (SEER) Program November 2008 submission database provided age-adjusted incidence rates and individual case information for primary brain tumors diagnosed between 1973 and 2006 in infants less than 12 months of age. Between 1973 and 1986, the incidence of infant brain tumors increased from 16 to 40 cases per million (CPM), and from 1986 to 2006, the annual incidence rate averaged 35 CPM. Leading histologies by annual incidence in CPM were gliomas (13.8), medulloblastoma and primitive neuroectodermal tumors (6.6), and ependymomas (3.6). The annual incidence was higher in whites than in blacks (35.0 vs. 21.3 CPM). Infants with low-grade gliomas had the highest observed survival, and those with atypical teratoid rhabdoid tumors (ATRTs) or primary rhabdoid tumors of the brain had the lowest. Between 1979 and 1993, the annual rate of cases treated with radiation within the first 4 months from diagnosis declined from 20.5 CPM to incidence of infant brain tumors has been stable since 1986. Survival outcomes varied markedly by histology. For infants with medulloblastoma and ATRTs, improved survival was observed in patients treated with both surgery and early radiation compared with those treated with surgery alone. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Thallium brain SPECT and MRI correlation in the evaluation of tumour recurrence versus radiation necrosis

    International Nuclear Information System (INIS)

    Robins, P.D.; Mahoney, D.S.; Mullan, B.P.

    2000-01-01

    Full text: This study compares different methods of determining thallium tumour uptake indices. Correlation with MR was performed to evaluate features that may affect the thallium index (TI) and to improve specificity for differentiation of recurrent tumor from radiation necrosis. 23 patients who had received radiotherapy for a brain neoplasm were included. The TI was determined using three different methods including large and small regions-of-interest (ROI). The concordance between the thallium SPECT and MRI was assessed. The effect of central necrosis on the different thallium indices derived was evaluated. 18 patients were determined to have recurrent tumor and five had inactive disease. The optimal TI cut-off values was statistically delivered and sensitivity and specificity was 78-94% and 80% respectively for cut-off values between 2.0 and 2.6 depending on the method used to calculate the TI. When compared with MRI, the majority of SPECT abnormalities correlated well with location and degree of uptake and enhancement. Seven cases showed central necrosis and the degree of necrosis had less effect on the TI when a small ROI was used in these cases. In conclusion thallium brain SPECT is a sensitive technique for detecting recurrent tumour. When performing semi-quantitative assessment of thallium uptake, a smaller ROI over the most intense area of uptake will reduce the underestimation of the TI in the presence of necrosis and a Tl cut-off value of 2.6 gave optimal accuracy using this method. Correlation with MRI aids in localization, particularly where there is anatomic distortion and enables more accurate analysis of these lesions by avoiding areas of necrosis. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

  9. Reduction in radiation dose with reconstruction technique in the brain perfusion CT

    Science.gov (United States)

    Kim, H. J.; Lee, H. K.; Song, H.; Ju, M. S.; Dong, K. R.; Chung, W. K.; Cho, M. S.; Cho, J. H.

    2011-12-01

    The principal objective of this study was to verify the utility of the reconstruction imaging technique in the brain perfusion computed tomography (PCT) scan by assessing reductions in the radiation dose and analyzing the generated images. The setting used for image acquisition had a detector coverage of 40 mm, a helical thickness of 0.625 mm, a helical shuttle mode scan type and a rotation time of 0.5 s as the image parameters used for the brain PCT scan. Additionally, a phantom experiment and an animal experiment were carried out. In the phantom and animal experiments, noise was measured in the scanning with the tube voltage fixed at 80 kVp (kilovolt peak) and the level of the adaptive statistical iterative reconstruction (ASIR) was changed from 0% to 100% at 10% intervals. The standard deviation of the CT coefficient was measured three times to calculate the mean value. In the phantom and animal experiments, the absorbed dose was measured 10 times under the same conditions as the ones for noise measurement before the mean value was calculated. In the animal experiment, pencil-type and CT-dedicated ionization chambers were inserted into the central portion of pig heads for measurement. In the phantom study, as the level of the ASIR changed from 0% to 100% under identical scanning conditions, the noise value and dose were proportionally reduced. In our animal experiment, the noise value was lowest when the ASIR level was 50%, unlike in the phantom study. The dose was reduced as in the phantom study.

  10. Study of the fluctuations of the partial and total radiative widths by neutron capture resonance method; Etude des fluctuations des largeurs radiatives partielles et totales par la capture des neutrons de resonance

    Energy Technology Data Exchange (ETDEWEB)

    Huynh, V D [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-06-01

    Radiative capture experiments by neutron time-of-flight methods have been made for following studies: distribution of partial radiative widths, effects of correlation between different radiative transitions, fluctuations of total radiative widths {gamma}{sub {gamma}} from resonance to resonance, variation of {gamma}{sub {gamma}} with number of mass and the search for the existence of potential capture. Also, some other experiments with the use of neutron capture gamma-rays spectra have been investigated. (author) [French] Par la capture des neutrons de resonance dont les energies sont selectionnees a l'aide de la technique du temps de vol, differents types d'experiences ont ete realisees concernant les etudes des distributions des largeurs radiatives partielles, des effets de correlation entre differentes voies de desexcitation, de la fluctuation des largeurs radiatives totales {gamma}{sub {gamma}} de resonance a resonance, de la variation de la quantite {gamma}{sub {gamma}} en fonction du nombre de masse et de la mise en evidence de l'existence du processus de capture potentielle. Quelques autres applications de l'emploi du spectre de rayons gamma ont egalement ete presentees. (auteur)

  11. Study of the fluctuations of the partial and total radiative widths by neutron capture resonance method; Etude des fluctuations des largeurs radiatives partielles et totales par la capture des neutrons de resonance

    Energy Technology Data Exchange (ETDEWEB)

    Huynh, V.D. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-06-01

    Radiative capture experiments by neutron time-of-flight methods have been made for following studies: distribution of partial radiative widths, effects of correlation between different radiative transitions, fluctuations of total radiative widths {gamma}{sub {gamma}} from resonance to resonance, variation of {gamma}{sub {gamma}} with number of mass and the search for the existence of potential capture. Also, some other experiments with the use of neutron capture gamma-rays spectra have been investigated. (author) [French] Par la capture des neutrons de resonance dont les energies sont selectionnees a l'aide de la technique du temps de vol, differents types d'experiences ont ete realisees concernant les etudes des distributions des largeurs radiatives partielles, des effets de correlation entre differentes voies de desexcitation, de la fluctuation des largeurs radiatives totales {gamma}{sub {gamma}} de resonance a resonance, de la variation de la quantite {gamma}{sub {gamma}} en fonction du nombre de masse et de la mise en evidence de l'existence du processus de capture potentielle. Quelques autres applications de l'emploi du spectre de rayons gamma ont egalement ete presentees. (auteur)

  12. SU-D-BRD-06: Automated Population-Based Planning for Whole Brain Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Schreibmann, E; Fox, T; Crocker, I; Shu, H [Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, GA (United States)

    2014-06-01

    Purpose: Treatment planning for whole brain radiation treatment is technically a simple process but in practice it takes valuable clinical time of repetitive and tedious tasks. This report presents a method that automatically segments the relevant target and normal tissues and creates a treatment plan in only a few minutes after patient simulation. Methods: Segmentation is performed automatically through morphological operations on the soft tissue. The treatment plan is generated by searching a database of previous cases for patients with similar anatomy. In this search, each database case is ranked in terms of similarity using a customized metric designed for sensitivity by including only geometrical changes that affect the dose distribution. The database case with the best match is automatically modified to replace relevant patient info and isocenter position while maintaining original beam and MLC settings. Results: Fifteen patients were used to validate the method. In each of these cases the anatomy was accurately segmented to mean Dice coefficients of 0.970 ± 0.008 for the brain, 0.846 ± 0.009 for the eyes and 0.672 ± 0.111 for the lens as compared to clinical segmentations. Each case was then subsequently matched against a database of 70 validated treatment plans and the best matching plan (termed auto-planned), was compared retrospectively with the clinical plans in terms of brain coverage and maximum doses to critical structures. Maximum doses were reduced by a maximum of 20.809 Gy for the left eye (mean 3.533), by 13.352 (1.311) for the right eye, and by 27.471 (4.856), 25.218 (6.315) for the left and right lens. Time from simulation to auto-plan was 3-4 minutes. Conclusion: Automated database- based matching is an alternative to classical treatment planning that improves quality while providing a cost—effective solution to planning through modifying previous validated plans to match a current patient's anatomy.

  13. Phase-and-amplitude recovery from a single phase-contrast image using partially spatially coherent x-ray radiation

    Science.gov (United States)

    Beltran, Mario A.; Paganin, David M.; Pelliccia, Daniele

    2018-05-01

    A simple method of phase-and-amplitude extraction is derived that corrects for image blurring induced by partially spatially coherent incident illumination using only a single intensity image as input. The method is based on Fresnel diffraction theory for the case of high Fresnel number, merged with the space-frequency description formalism used to quantify partially coherent fields and assumes the object under study is composed of a single-material. A priori knowledge of the object’s complex refractive index and information obtained by characterizing the spatial coherence of the source is required. The algorithm was applied to propagation-based phase-contrast data measured with a laboratory-based micro-focus x-ray source. The blurring due to the finite spatial extent of the source is embedded within the algorithm as a simple correction term to the so-called Paganin algorithm and is also numerically stable in the presence of noise.

  14. Adverse radiation effect after stereotactic radiosurgery for brain metastases: incidence, time course, and risk factors.

    Science.gov (United States)

    Sneed, Penny K; Mendez, Joe; Vemer-van den Hoek, Johanna G M; Seymour, Zachary A; Ma, Lijun; Molinaro, Annette M; Fogh, Shannon E; Nakamura, Jean L; McDermott, Michael W

    2015-08-01

    The authors sought to determine the incidence, time course, and risk factors for overall adverse radiation effect (ARE) and symptomatic ARE after stereotactic radiosurgery (SRS) for brain metastases. All cases of brain metastases treated from 1998 through 2009 with Gamma Knife SRS at UCSF were considered. Cases with less than 3 months of follow-up imaging, a gap of more than 8 months in imaging during the 1st year, or inadequate imaging availability were excluded. Brain scans and pathology reports were reviewed to ensure consistent scoring of dates of ARE, treatment failure, or both; in case of uncertainty, the cause of lesion worsening was scored as indeterminate. Cumulative incidence of ARE and failure were estimated with the Kaplan-Meier method with censoring at last imaging. Univariate and multivariate Cox proportional hazards analyses were performed. Among 435 patients and 2200 brain metastases evaluable, the median patient survival time was 17.4 months and the median lesion imaging follow-up was 9.9 months. Calculated on the basis of 2200 evaluable lesions, the rates of treatment failure, ARE, concurrent failure and ARE, and lesion worsening with indeterminate cause were 9.2%, 5.4%, 1.4%, and 4.1%, respectively. Among 118 cases of ARE, approximately 60% were symptomatic and 85% occurred 3-18 months after SRS (median 7.2 months). For 99 ARE cases managed without surgery or bevacizumab, the probabilities of improvement observed on imaging were 40%, 57%, and 76% at 6, 12, and 18 months after onset of ARE. The most important risk factors for ARE included prior SRS to the same lesion (with 20% 1-year risk of symptomatic ARE vs 3%, 4%, and 8% for no prior treatment, prior whole brain radiotherapy [WBRT], or concurrent WBRT) and any of these volume parameters: target, prescription isodose, 12-Gy, or 10-Gy volume. Excluding lesions treated with repeat SRS, the 1-year probabilities of ARE were 2.1 cm, target volume > 1.2 cm(3), prescription isodose volume > 1.8 cm(3

  15. Radiation-induced changes in nucleoid halo diameteres of aerobic and hypoxic SF-126 human brain tumor cells

    International Nuclear Information System (INIS)

    Wang, J.; Basu, H.S.; Hu, L.; Feuerstein, B.G.; Deen, D.F.

    1995-01-01

    Nucleoid halo diameters were measured to assay changes in DNA supercoiling in human brain tumor cell line SF-126 after irradiation under aerobic or hypoxic conditions. In unirradiated aerobic cells, a typical propidium iodide titration curve showed that with increasing concentrations of propodium iodide, the halo diameter increased and then decreased with the unwinding and subsequent rewinding of DNA supercoils. In irradiated cells, the rewinding of DNA supercoils was inhibited, resulting in an increased halo diameter, in a radiation dose-dependent manner. To produce equal increases in halo diameter required about a threefold higher radiation dose in hypoxic cells than in aerobic cells. Quantitatively similiar differences in the radiation sensitivities of hypoxic and aerobic cells were demonstrated by a colony-forming efficiency assay. These findings suggest that the nucleoid halo assay may be used as a rapid measure of the inherent radiation sensitivity of human tumors. 22 refs., 5 figs

  16. Establishment of an open database of realistic simulated data for evaluation of partial volume correction techniques in brain PET/MR

    Energy Technology Data Exchange (ETDEWEB)

    Mota, Ana [Instituto de Biofísica e Engenharia Biomédica, FC-UL, Lisboa (Portugal); Institute of Nuclear Medicine, UCL, London (United Kingdom); Cuplov, Vesna [Instituto de Biofísica e Engenharia Biomédica, FC-UL, Lisboa (Portugal); Schott, Jonathan; Hutton, Brian; Thielemans, Kris [Institute of Nuclear Medicine, UCL, London (United Kingdom); Drobnjak, Ivana [Centre of Medical Image Computing, UCL, London (United Kingdom); Dickson, John [Institute of Nuclear Medicine, UCL, London (United Kingdom); Bert, Julien [INSERM UMR1101, LaTIM, CHRU de Brest, Brest (France); Burgos, Ninon; Cardoso, Jorge; Modat, Marc; Ourselin, Sebastien [Centre of Medical Image Computing, UCL, London (United Kingdom); Erlandsson, Kjell [Institute of Nuclear Medicine, UCL, London (United Kingdom)

    2015-05-18

    The Partial Volume (PV) effect in Positron Emission Tomography (PET) imaging leads to loss in quantification accuracy, which manifests in PV effects (small objects occupy partially the sensitive volume of the imaging instrument, resulting in blurred images). Simultaneous acquisition of PET and Magnetic Resonance Imaging (MRI) produces concurrent metabolic and anatomical information. The latter has proved to be very helpful for the correction of PV effects. Currently, there are several techniques used for PV correction. They can be applied directly during the reconstruction process or as a post-processing step after image reconstruction. In order to evaluate the efficacy of the different PV correction techniques in brain- PET, we are constructing a database of simulated data. Here we present the framework and steps involved in constructing this database. Static 18F-FDG epilepsy and 18F-Florbetapir amyloid dementia PET/MR were selected because of their very different characteristics. The methodology followed was based on four main steps: Image pre-processing, Ground Truth (GT) generation, MRI and PET data simulation and reconstruction. All steps used Open Source software and can therefore be repeated at any centre. The framework as well as the database will be freely accessible. Tools used included GIF, FSL, POSSUM, GATE and STIR. The final data obtained after simulation, involving raw or reconstructed PET data together with corresponding MRI datasets, were close to the original patient data. Besides, there is the advantage that data can be compared with the GT. We indicate several parameters that can be improved and optimized.

  17. Establishment of an open database of realistic simulated data for evaluation of partial volume correction techniques in brain PET/MR

    International Nuclear Information System (INIS)

    Mota, Ana; Cuplov, Vesna; Schott, Jonathan; Hutton, Brian; Thielemans, Kris; Drobnjak, Ivana; Dickson, John; Bert, Julien; Burgos, Ninon; Cardoso, Jorge; Modat, Marc; Ourselin, Sebastien; Erlandsson, Kjell

    2015-01-01

    The Partial Volume (PV) effect in Positron Emission Tomography (PET) imaging leads to loss in quantification accuracy, which manifests in PV effects (small objects occupy partially the sensitive volume of the imaging instrument, resulting in blurred images). Simultaneous acquisition of PET and Magnetic Resonance Imaging (MRI) produces concurrent metabolic and anatomical information. The latter has proved to be very helpful for the correction of PV effects. Currently, there are several techniques used for PV correction. They can be applied directly during the reconstruction process or as a post-processing step after image reconstruction. In order to evaluate the efficacy of the different PV correction techniques in brain- PET, we are constructing a database of simulated data. Here we present the framework and steps involved in constructing this database. Static 18F-FDG epilepsy and 18F-Florbetapir amyloid dementia PET/MR were selected because of their very different characteristics. The methodology followed was based on four main steps: Image pre-processing, Ground Truth (GT) generation, MRI and PET data simulation and reconstruction. All steps used Open Source software and can therefore be repeated at any centre. The framework as well as the database will be freely accessible. Tools used included GIF, FSL, POSSUM, GATE and STIR. The final data obtained after simulation, involving raw or reconstructed PET data together with corresponding MRI datasets, were close to the original patient data. Besides, there is the advantage that data can be compared with the GT. We indicate several parameters that can be improved and optimized.

  18. Efficacy of continuous treatment with radiation in a rat brain-tumor model

    International Nuclear Information System (INIS)

    Wheeler, K.T.; Kaufman, K.

    1981-01-01

    Rats bearing intracerebral 9L/Ro tumors were treated with 10 daily fractions of cesium-137 gamma-rays, BCNU, or combinations of these to agents beginning on either Day 10 or Day 12 after implantation. The treatments were administered either 5 days/week for 2 weeks, with the weekend off, or 10 consecutive days. The median day of death for untreated tumor-bearing rats was Day 15, so Day 12 tumors can be considered late tumors and Day 10 tumors can be considered moderately early. Although all single- and multiple-agent treatments significantly (p less than 0.05) increased the lifespan of tumor-bearing rats over that of the untreated controls, and all multiple-agent schedules significantly (p less than 0.05) increased the lifespan over that of the single-agent therapies, none of the 10 consecutive day schedules increased the lifespan of tumor-bearing rats significantly (p less than 0.2) over that obtained with the 5-day/week schedules. Thus, the evidence from this tumor model suggests that no significant improvement in lifespan would be expected if malignant brain tumors were treated with radiation 7 days a week, either alone or in combination with chemotherapeutic agents such as BCNU

  19. Histochemical changes of capillaries in rat brain cortex after irradiation with supralethal doses of gamma radiation

    International Nuclear Information System (INIS)

    Kamarad, V.; Dosoudilova, M.

    1987-01-01

    Changes were studied in the activities of alkaline phosphatase, ATP-splitting enzyme, thiaminepyrophosphatase, acetylcholinesterase, and of butyrylcholinesterase in the capillary sheet of the rat brain cortex of the laterobasal section of a parietal lobe following irradiation with 150 and 300 Gy. The animals were exposed to local irradiation of the head with gamma radiation using 60 Co at a dose rate of 6.9 Gy per min. The material was removed at the intervals of 30 and 60 mins after irradiation. All the studied enzymes, except the ATP-splitting enzyme, showed identical reaction to irradiation. At both intervals, the reaction after irradiation with 300 Gy was lower when compared to that after irradiation with 150 Gy. 30 mins after irradiation with 150 Gy an increased enzyme activity was shown followed by a marked decrease in the activity 60 mins after irradiation, compared with findings obtained from control animals. No similar time dependence was observed after irradiation with 300 Gy. The ATP-splitting enzyme showed a significant decrease in the activity 30 mins after irradiation with 150 Gy. On the other hand, 60 mins after irradiation with 150 Gy and at both time intervals after irradiation with 300 Gy, the activity was higher than that in control animals. (author). 6 figs., 14 refs

  20. Proportion of various dendromass components of spruce (Picea abies), and partial models for modification of wind speed and radiation by pure spruce stands

    International Nuclear Information System (INIS)

    Wollmerstädt, J.; Sharma, S.C.; Marsch, M.

    1992-01-01

    Means for quantifying dendromass components of spruce stands have been discussed, and partial models for modification of radiation and wind by the pure spruce stand were developed. By means of a sampling procedure, the components needle dry mass and branchwood dry mass without needles of individual trees are recorded. Using the relationship between branch basal diameter and needle respectively branchwood dry mass, the total needle and branchwood dry mass of trees is estimated. Based on that, stand or regional parameters for the allometric function between diameter breast height and needle respectively branchwood dry mass can be determined for defined H/D-clusters. Published data from various sources were used in this paper. The lowest coefficients of determination were found in H/D-cluster 120 (H/D-values over 114). Therefore, further differentiation within this range seems to be necessary. For assimilation models, there should be quantification of needle dry mass separately for needle age classes and morphological characteristics of needles. Basis for the estimate of tree-bole volume is the relationship between H/D-value and oven-dry weight. There are problems as far as methods for quantifying the subterranean dendromass (e.g. dynamics of fine roots) are concerned; this is requiring considerable efforts, too. Spatial structure was also described by allometric functions (crown length and crown cover in relation to diameter breast height). For the partial model to express wind modification by the stand, standardized wind profiles as related to crown canopy density were used. The modification of radiation by the stand is closely related with the vertical needle mass distribution (sum curves). These two partial models have to be considered as an approach for the description of the modifying effect by the stocking [de

  1. Influence of the partial volume correction method on (18)F-fluorodeoxyglucose brain kinetic modelling from dynamic PET images reconstructed with resolution model based OSEM.

    Science.gov (United States)

    Bowen, Spencer L; Byars, Larry G; Michel, Christian J; Chonde, Daniel B; Catana, Ciprian

    2013-10-21

    Kinetic parameters estimated from dynamic (18)F-fluorodeoxyglucose ((18)F-FDG) PET acquisitions have been used frequently to assess brain function in humans. Neglecting partial volume correction (PVC) for a dynamic series has been shown to produce significant bias in model estimates. Accurate PVC requires a space-variant model describing the reconstructed image spatial point spread function (PSF) that accounts for resolution limitations, including non-uniformities across the field of view due to the parallax effect. For ordered subsets expectation maximization (OSEM), image resolution convergence is local and influenced significantly by the number of iterations, the count density, and background-to-target ratio. As both count density and background-to-target values for a brain structure can change during a dynamic scan, the local image resolution may also concurrently vary. When PVC is applied post-reconstruction the kinetic parameter estimates may be biased when neglecting the frame-dependent resolution. We explored the influence of the PVC method and implementation on kinetic parameters estimated by fitting (18)F-FDG dynamic data acquired on a dedicated brain PET scanner and reconstructed with and without PSF modelling in the OSEM algorithm. The performance of several PVC algorithms was quantified with a phantom experiment, an anthropomorphic Monte Carlo simulation, and a patient scan. Using the last frame reconstructed image only for regional spread function (RSF) generation, as opposed to computing RSFs for each frame independently, and applying perturbation geometric transfer matrix PVC with PSF based OSEM produced the lowest magnitude bias kinetic parameter estimates in most instances, although at the cost of increased noise compared to the PVC methods utilizing conventional OSEM. Use of the last frame RSFs for PVC with no PSF modelling in the OSEM algorithm produced the lowest bias in cerebral metabolic rate of glucose estimates, although by less than 5% in

  2. Prognostic factors for survival and radiation necrosis after stereotactic radiosurgery alone or in combination with whole brain radiation therapy for 1–3 cerebral metastases

    International Nuclear Information System (INIS)

    Schüttrumpf, Lars Hendrik; Niyazi, Maximilian; Nachbichler, Silke Birgit; Manapov, Farkhad; Jansen, Nathalie; Siefert, Axel; Belka, Claus

    2014-01-01

    In the present study factors affecting survival and toxicity in cerebral metastasized patients treated with stereotactic radiosurgery (SRS) were analyzed with special focus on radiation necrosis. 340 patients with 1–3 cerebral metastases having been treated with SRS were retrospectively analyzed. Radiation necrosis was diagnosed by MRI und PET imaging. Univariate and multivariate analysis using a Cox proportional hazards regression model and log-rank test were performed to determine the prognostic value of treatment-related and individual factors for outcome and SRS-related complications. Median overall survival was 282 days and median follow-up 721 days. 44% of patients received WBRT during the course of disease. Concerning univariate analysis a significant difference in overall survival was found for Karnofsky Performance Status (KPS ≤ 70: 122 days; KPS > 70: 342 days), for RPA (recursive partitioning analysis) class (RPA class I: 1800 days; RPA class II: 281 days; RPA class III: 130 days), irradiated volume (≤2.5 ml: 354 days; > 2.5 ml: 234 days), prescribed dose (≤18 Gy: 235 days; > 18 Gy: 351 days), gender (male: 235 days; female: 327 days) and whole brain radiotherapy (+WBRT: 341 days/-WBRT: 231 days). In multivariate analysis significance was confirmed for KPS, RPA class and gender. MRI and clinical symptoms suggested radiation necrosis in 21 patients after SRS +/− whole brain radiotherapy (WBRT). In five patients clinically relevant radiation necrosis was confirmed by PET imaging. SRS alone or in combination with WBRT represents a feasible option as initial treatment for patients with brain metastases; however a significant subset of patients may develop neurological complications. Performance status, RPA class and gender were identified to predict improved survival in cerebral metastasized patients

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

    International Nuclear Information System (INIS)

    Picano, Eugenio; Vano, Eliseo; Domenici, Luciano; Bottai, Matteo; Thierry-Chef, Isabelle

    2012-01-01

    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. 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 < 200 mSv, but with head exposure which may (in absence of protection) arrive at a head equivalent dose of 1 to 3 Sv after a professional lifetime (corresponding to a brain equivalent dose around 500 mSv). 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

  4. Cerebrovascular Remodeling and Neuroinflammation is a Late Effect of Radiation-Induced Brain Injury in Non-Human Primates

    Science.gov (United States)

    Andrews, Rachel N.; Metheny-Barlow, Linda J.; Peiffer, Ann M.; Hanbury, David B.; Tooze, Janet A.; Bourland, J. Daniel; Hampson, Robert E.; Deadwyler, Samuel A.; Cline, J. Mark

    2017-01-01

    Andrews, R. N., Metheny-Barlow, L. J., Peiffer, A. M., Hanbury, D. B., Tooze, J. A., Bourland, J. D., Hampson, R. E., Deadwyler, S. A. and Cline, J. M. Cerebrovascular Remodeling and Neuroinflammation is a Late Effect of Radiation-Induced Brain Injury in Non-Human Primates. Radiat. Res. 187, 599–611 (2017). Fractionated whole-brain irradiation (fWBI) is a mainstay of treatment for patients with intracranial neoplasia; however late-delayed radiation-induced normal tissue injury remains a major adverse consequence of treatment, with deleterious effects on quality of life for affected patients. We hypothesize that cerebrovascular injury and remodeling after fWBI results in ischemic injury to dependent white matter, which contributes to the observed cognitive dysfunction. To evaluate molecular effectors of radiation-induced brain injury (RIBI), real-time quantitative polymerase chain reaction (RT-qPCR) was performed on the dorsolateral prefrontal cortex (DLPFC, Brodmann area 46), hippocampus and temporal white matter of 4 male Rhesus macaques (age 6–11 years), which had received 40 Gray (Gy) fWBI (8 fractions of 5 Gy each, twice per week), and 3 control comparators. All fWBI animals developed neurologic impairment; humane euthanasia was elected at a median of 6 months. Radiation-induced brain injury was confirmed histopathologically in all animals, characterized by white matter degeneration and necrosis, and multifocal cerebrovascular injury consisting of perivascular edema, abnormal angiogenesis and perivascular extracellular matrix deposition. Herein we demonstrate that RIBI is associated with white matter-specific up-regulation of hypoxia-associated lactate dehydrogenase A (LDHA) and that increased gene expression of fibronectin 1 (FN1), SERPINE1 and matrix metalloprotease 2 (MMP2) may contribute to cerebrovascular remodeling in late-delayed RIBI. Additionally, vascular stability and maturation associated tumor necrosis super family member 15 (TNFSF15) and

  5. Pomegranate Alleviates Oxidative Damage and Neurotransmitter Alterations in Rats Brain Exposed to Aluminum Chloride and/or Gamma Radiation

    International Nuclear Information System (INIS)

    Said, U.Z.; EL-Tahawey, N.A.; Elassal, A.A.; Elsayed, E.M.; Shousha, W.Gh.

    2013-01-01

    Aluminum and gamma radiation, both are potent neurotoxins and have been implicated in many human neuro degenerative diseases. The present study was designed to investigate the role of pomegranate in alleviating oxidative damage and alteration of neurotransmitters in the brain of rats exposed to aluminum chloride (AlCl 3 ), and/or gamma radiation (IR). The results revealed that rats whole body exposed to γ- rays, (1 Gy/week up to 4 Gy), and/or administered aluminum chloride (35 mg/kg body weight), via gavages for 4 weeks, resulted in brain tissue damage, featuring by significant increase of the level of thiobarbituric acid reactive substances (TBARS), and advanced oxidation protein products (AOPP), associated with significant decrease of superoxide dismutase (SOD) and catalase (CAT) activities, as well as glutathione (GSH) content indicating occurrence of oxidative stress. A significant decrease of serotonin (5-HT) level associated with a significant increase of 5-hydroxyindole acetic acid (5-HIAA), in addition to a significant decrease in dopamine (DA), norepinephrine (NE) and epinephrine (EPI) contents recorded at the 1st, 7th and 14th day post-irradiation, indicating alterations in the metabolism of brain monoamines. On the other hand, the results exhibited that, supplementation of rats with pomegranate, via gavages, at a dose of 3 ml /kg body weight/ day, for 4 weeks along with AlCl 3 with or without radiation has significantly ameliorated the changes occurred in the mentioned parameters and the values returned close to the normal ones. It could be concluded that pomegranate, by its antioxidant constituents might antagonize brain oxidative damage and minimize the severity of aluminum (Al), and/or radiation-induced neurotransmitters disorders

  6. Blood-brain barrier permeation in the rat during exposure to low-power 1.7-GHz microwave radiation

    International Nuclear Information System (INIS)

    Ward, T.R.; Ali, J.S.

    1985-01-01

    The permeability of the blood-brain barrier to high-and low-molecular-weight compounds has been measured as a function of continuous-wave (CW) and pulsed-microwave radiation. Adult rats, anesthetized with pentobarbital and injected intravenously with a mixture of [ 14 C] sucrose and [ 3 H] inulin, were exposed for 30 min at a specific absorption rate of 0.1 W/kg to 1.7-GHz CW and pulsed (0.5-microseconds pulse width, 1,000 pps) microwaves. After exposure, the brain was perfused and sectioned into nine regions, and the radioactivity in each region was counted. During identical exposure conditions, temperatures of rats were measured in eight of the brain regions by a thermistor probe that did not perturb the field. No change in uptake of either tracer was found in any of the eight regions as compared with those of sham-exposed animals

  7. Neuroprotection of hyperbaric oxygen therapy in sub-acute traumatic brain injury: not by immediately improving cerebral oxygen saturation and oxygen partial pressure.

    Science.gov (United States)

    Zhou, Bao-Chun; Liu, Li-Jun; Liu, Bing

    2016-09-01

    Although hyperbaric oxygen (HBO) therapy can promote the recovery of neural function in patients who have suffered traumatic brain injury (TBI), the underlying mechanism is unclear. We hypothesized that hyperbaric oxygen treatment plays a neuroprotective role in TBI by increasing regional transcranial oxygen saturation (rSO 2 ) and oxygen partial pressure (PaO 2 ). To test this idea, we compared two groups: a control group with 20 healthy people and a treatment group with 40 TBI patients. The 40 patients were given 100% oxygen of HBO for 90 minutes. Changes in rSO 2 were measured. The controls were also examined for rSO 2 and PaO 2 , but received no treatment. rSO 2 levels in the patients did not differ significantly after treatment, but levels before and after treatment were significantly lower than those in the control group. PaO 2 levels were significantly decreased after the 30-minute HBO treatment. Our findings suggest that there is a disorder of oxygen metabolism in patients with sub-acute TBI. HBO does not immediately affect cerebral oxygen metabolism, and the underlying mechanism still needs to be studied in depth.

  8. Effects of sublethal doses of gamma radiation on the developing rat brain

    International Nuclear Information System (INIS)

    Cerda, H.; Carlsson, J.; Larsson, B.; Saefwenberg, J.O.

    1975-01-01

    Newborn rats were irradiated with 60 Co gamma rays. Doses of 0, 80 or 160 rads were given to the whole body. The whole body and brain weights, DNA and RNA contents of the brain and 3 H-thymidine or 3 H-uridine incorporated by the brain were measured at 5, 10 or 15 days after birth. A dose of 160 rads produced clear alterations in the brain but no clear effects could be detected when 80 rads were given. (author)

  9. Dynamics of pathomorphological changes in rat brain as a function of γ-radiation dose

    International Nuclear Information System (INIS)

    Fedorov, V.P.

    1990-01-01

    Neurohistological, histochemical, electron-microscopic and biometric techniques were used to study the response of rat brain to irradiation within a wide range of doses. Nerve cells were shown to be highly radioresistant. At the same time, synapses and blood-brain barrier structures were highly radiosensitive. The pathomorphologic changes in different brain areas followed a dose-time function

  10. Balloon brachytherapy for brain tumor-radiation safety experiences at the University of Medicine and Dentistry of New Jersey.

    Science.gov (United States)

    Lanka, Venkata K

    2006-11-01

    Balloon brachytherapy is a technique for the removal of a brain tumor in which an inflatable balloon is placed in a resection cavity and then filled with liquid I, delivering low energy dose to the cancerous cells surrounding the cavity. After preparing a patient room to mitigate any spills or contamination, liquid 125I (Iotrex) was assayed with a dose calibrator and injected into the balloon placed in the patient's brain. Approximately 98.6% of the isotope was recovered at the end of the procedure. Approximately 1.4% remained unrecovered and is assumed to have diffused through the balloon membrane. Each day, the patient's urine was collected and the total urine activity measured was less than 7% of the unrecovered activity. The remainder of the unrecovered activity was not evaluated. It was assumed to be distributed in the patient's body, and a tiny quantity of liquid spilled from an IV line while injecting. Training was conducted for radiation oncologists, neurosurgeons, and participating residents regarding balloon brachytherapy radiation safety precautions. Precautions during treatment included safe handling of body fluids. General radiation safety precautions and nursing care instructions were posted on the patient door. Air monitoring was conducted to detect any airborne iodine. At the time of balloon removal, the radiation safety department monitored the operating room and staff for contamination. Waste, including the balloon, was held for decay on site prior to disposal.

  11. Brain Tumors (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Brain Tumors KidsHealth / For Parents / Brain Tumors What's in ... radiation therapy or chemotherapy, or both. Types of Brain Tumors There are many different types of brain ...

  12. Bevacizumab and gefitinib enhanced whole-brain radiation therapy for brain metastases due to non-small-cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yang, R.F.; Yu, B.; Zhang, R.Q.; Wang, X.H.; Li, C.; Wang, P.; Zhang, Y.; Han, B.; Gao, X.X.; Zhang, L. [Taian City Central Hospital, Taian, Shandong (China); Jiang, Z.M., E-mail: dmyh2436@126.com [Qianfoshan Hospital of Shandong Province, Shandong University, Ji’nan, Shandong (China)

    2018-02-01

    Non-small-cell lung cancer (NSCLC) patients who experience brain metastases are usually associated with poor prognostic outcomes. This retrospective study proposed to assess whether bevacizumab or gefitinib can be used to improve the effectiveness of whole brain radiotherapy (WBRT) in managing patients with brain metastases. A total of 218 NSCLC patients with multiple brain metastases were retrospectively included in this study and were randomly allocated to bevacizumab-gefitinibWBRT group (n=76), gefitinib-WBRT group (n=77) and WBRT group (n=75). Then, tumor responses were evaluated every 2 months based on Response Evaluation Criteria in Solid Tumors version 1.0. Karnofsky performance status and neurologic examination were documented every 6 months after the treatment. Compared to the standard WBRT, bevacizumab and gefitinib could significantly enhance response rate (RR) and disease control rate (DCR) of WBRT (Po0.001). At the same time, RR and DCR of patients who received bevacizumab-gefitinib-WBRT were higher than those who received gefitinib-WBRT. The overall survival (OS) rates and progression-free survival (PFS) rates also differed significantly among the bevacizumab-gefitinib-WBRT (48.6 and 29.8%), gefitinib-WBRT (36.7 and 29.6%) and WBRT (9.8 and 14.6%) groups (Po0.05). Although bevacizumabgefitinib-WBRT was slightly more toxic than gefitinib-WBRT, the toxicity was tolerable. As suggested by prolonged PFS and OS status, bevacizumab substantially improved the overall efficacy of WBRT in the management of patients with NSCLC. (author)

  13. Early Brain Response to Low-Dose Radiation Exposure Involves Molecular Networks and Pathways Associated with Cognitive Functions, Advanced Aging and Alzheimer's Disease

    International Nuclear Information System (INIS)

    Lowe, Xiu R.; Bhattacharya, Sanchita; Marchetti, Francesco; Wyrobek, Andrew J.

    2008-01-01

    Understanding the cognitive and behavioral consequences of brain exposures to low-dose ionizing radiation has broad relevance for health risks from medical radiation diagnostic procedures, radiotherapy, environmental nuclear contamination, as well as earth orbit and space missions. Analyses of transcriptome profiles of murine brain tissue after whole-body radiation showed that low-dose exposures (10 cGy) induced genes not affected by high dose (2 Gy), and low-dose genes were associated with unique pathways and functions. The low-dose response had two major components: pathways that are consistently seen across tissues, and pathways that were brain tissue specific. Low-dose genes clustered into a saturated network (p -53 ) containing mostly down-regulated genes involving ion channels, long-term potentiation and depression, vascular damage, etc. We identified 9 neural signaling pathways that showed a high degree of concordance in their transcriptional response in mouse brain tissue after low-dose radiation, in the aging human brain (unirradiated), and in brain tissue from patients with Alzheimer's disease. Mice exposed to high-dose radiation did not show these effects and associations. Our findings indicate that the molecular response of the mouse brain within a few hours after low-dose irradiation involves the down-regulation of neural pathways associated with cognitive dysfunctions that are also down regulated in normal human aging and Alzheimer's disease

  14. Early Brain Response to Low-Dose Radiation Exposure Involves Molecular Networks and Pathways Associated with Cognitive Functions, Advanced Aging and Alzheimer's Disease

    Energy Technology Data Exchange (ETDEWEB)

    Lowe, Xiu R; Bhattacharya, Sanchita; Marchetti, Francesco; Wyrobek, Andrew J.

    2008-06-06

    Understanding the cognitive and behavioral consequences of brain exposures to low-dose ionizing radiation has broad relevance for health risks from medical radiation diagnostic procedures, radiotherapy, environmental nuclear contamination, as well as earth orbit and space missions. Analyses of transcriptome profiles of murine brain tissue after whole-body radiation showed that low-dose exposures (10 cGy) induced genes not affected by high dose (2 Gy), and low-dose genes were associated with unique pathways and functions. The low-dose response had two major components: pathways that are consistently seen across tissues, and pathways that were brain tissue specific. Low-dose genes clustered into a saturated network (p < 10{sup -53}) containing mostly down-regulated genes involving ion channels, long-term potentiation and depression, vascular damage, etc. We identified 9 neural signaling pathways that showed a high degree of concordance in their transcriptional response in mouse brain tissue after low-dose radiation, in the aging human brain (unirradiated), and in brain tissue from patients with Alzheimer's disease. Mice exposed to high-dose radiation did not show these effects and associations. Our findings indicate that the molecular response of the mouse brain within a few hours after low-dose irradiation involves the down-regulation of neural pathways associated with cognitive dysfunctions that are also down regulated in normal human aging and Alzheimer's disease.

  15. Prenatal ionizing radiation-induced apoptosis of the developing murine brain with special references to the expression of some proteins

    Energy Technology Data Exchange (ETDEWEB)

    Kitamura, Makiko; Itoh, Kyoko; Matsumoto, Akira; Hayashi, Yoshitake; Sasaki, Ryohei; Imai, Yukihiro; Itoh, Hiroshi [Kobe Univ. (Japan). School of Medicine

    2001-04-01

    Apoptosis induced by ionizing irradiation of the developing mouse brain was investigated by using histology, analysis of DNA fragmentation on agarose gel and electron microscopy. A TUNEL-labeled index (L.I.) was calculated from the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) assay in 4 specific regions, cortical plate, intermediate zone, subependymal zone, and subependymal germinal matrix. The kinetics of apoptosis associated protein was examined by western blotting and immunofluorescence. C57BL/6J mice pregnant on embryonic day 14 (E14) were exposed to a single dose of 1.5-Gy irradiation. Irradiaited fetal brains at E15 and E17 showed extensive apoptosis with morphological characteristics. In all 4 regions, L.I. was greater in irradiated brains than in control brains at E15 and E17. Most of TUNEL-labeled cells expressed a mature neuronal marker (NeuN) and Bax protein, which is up-regulated in irradiation-induced apoptosis. Ionizing radiation moderately enhanced expression of Bax, Bcl-xL, and Cpp32 proteins. Postnatal irradiated mice showed microencephaly as compared to age-matched mice and the weight of whole body including brain decreased moderately. (author)

  16. Prenatal ionizing radiation-induced apoptosis of the developing murine brain with special references to the expression of some proteins

    International Nuclear Information System (INIS)

    Kitamura, Makiko; Itoh, Kyoko; Matsumoto, Akira; Hayashi, Yoshitake; Sasaki, Ryohei; Imai, Yukihiro; Itoh, Hiroshi

    2001-01-01

    Apoptosis induced by ionizing irradiation of the developing mouse brain was investigated by using histology, analysis of DNA fragmentation on agarose gel and electron microscopy. A TUNEL-labeled index (L.I.) was calculated from the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) assay in 4 specific regions, cortical plate, intermediate zone, subependymal zone, and subependymal germinal matrix. The kinetics of apoptosis associated protein was examined by western blotting and immunofluorescence. C57BL/6J mice pregnant on embryonic day 14 (E14) were exposed to a single dose of 1.5-Gy irradiation. Irradiated fetal brains at E15 and E17 showed extensive apoptosis with morphological characteristics. In all 4 regions, L.I. was greater in irradiated brains than in control brains at E15 and E17. Most of TUNEL-labeled cells expressed a mature neuronal marker (NeuN) and Bax protein, which is up-regulated in irradiation-induced apoptosis. Ionizing radiation moderately enhanced expression of Bax, Bcl-xL, and Cpp32 proteins. Postnatal irradiated mice showed microencephaly as compared to age-matched mice and the weight of whole body including brain decreased moderately. (author)

  17. Phase 3 Trials of Stereotactic Radiosurgery With or Without Whole-Brain Radiation Therapy for 1 to 4 Brain Metastases: Individual Patient Data Meta-Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sahgal, Arjun, E-mail: arjun.sahgal@sunnybrook.ca [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Aoyama, Hidefumi [Department of Radiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata (Japan); Kocher, Martin [Department of Radiation Oncology, University of Cologne, Cologne (Germany); Neupane, Binod [Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario (Canada); Collette, Sandra [Statistics Department, European Organisation for Research and Treatment of Cancer, Brussels (Belgium); Tago, Masao [Department of Radiology, Teikyo University Mizonokuchi Hospital, Kanagawa (Japan); Shaw, Prakesh [Department of Pediatrics, Mount Sinai Hospital, Institute of Health Policy Management and Evaluation, University of Toronto, Ontario (Canada); Beyene, Joseph [Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario (Canada); Chang, Eric L. [Department of Radiation Oncology, University of Southern California, Los Angeles, California (United States); Department of Radiation Oncology, MD Anderson Cancer Center, Houston, Texas (United States)

    2015-03-15

    Purpose: To perform an individual patient data (IPD) meta-analysis of randomized controlled trials evaluating stereotactic radiosurgery (SRS) with or without whole-brain radiation therapy (WBRT) for patients presenting with 1 to 4 brain metastases. Method and Materials: Three trials were identified through a literature search, and IPD were obtained. Outcomes of interest were survival, local failure, and distant brain failure. The treatment effect was estimated after adjustments for age, recursive partitioning analysis (RPA) score, number of brain metastases, and treatment arm. Results: A total of 364 of the pooled 389 patients met eligibility criteria, of whom 51% were treated with SRS alone and 49% were treated with SRS plus WBRT. For survival, age was a significant effect modifier (P=.04) favoring SRS alone in patients ≤50 years of age, and no significant differences were observed in older patients. Hazard ratios (HRs) for patients 35, 40, 45, and 50 years of age were 0.46 (95% confidence interval [CI] = 0.24-0.90), 0.52 (95% CI = 0.29-0.92), 0.58 (95% CI = 0.35-0.95), and 0.64 (95% CI = 0.42-0.99), respectively. Patients with a single metastasis had significantly better survival than those who had 2 to 4 metastases. For distant brain failure, age was a significant effect modifier (P=.043), with similar rates in the 2 arms for patients ≤50 of age; otherwise, the risk was reduced with WBRT for patients >50 years of age. Patients with a single metastasis also had a significantly lower risk of distant brain failure than patients who had 2 to 4 metastases. Local control significantly favored additional WBRT in all age groups. Conclusions: For patients ≤50 years of age, SRS alone favored survival, in addition, the initial omission of WBRT did not impact distant brain relapse rates. SRS alone may be the preferred treatment for this age group.

  18. Phase 3 Trials of Stereotactic Radiosurgery With or Without Whole-Brain Radiation Therapy for 1 to 4 Brain Metastases: Individual Patient Data Meta-Analysis

    International Nuclear Information System (INIS)

    Sahgal, Arjun; Aoyama, Hidefumi; Kocher, Martin; Neupane, Binod; Collette, Sandra; Tago, Masao; Shaw, Prakesh; Beyene, Joseph; Chang, Eric L.

    2015-01-01

    Purpose: To perform an individual patient data (IPD) meta-analysis of randomized controlled trials evaluating stereotactic radiosurgery (SRS) with or without whole-brain radiation therapy (WBRT) for patients presenting with 1 to 4 brain metastases. Method and Materials: Three trials were identified through a literature search, and IPD were obtained. Outcomes of interest were survival, local failure, and distant brain failure. The treatment effect was estimated after adjustments for age, recursive partitioning analysis (RPA) score, number of brain metastases, and treatment arm. Results: A total of 364 of the pooled 389 patients met eligibility criteria, of whom 51% were treated with SRS alone and 49% were treated with SRS plus WBRT. For survival, age was a significant effect modifier (P=.04) favoring SRS alone in patients ≤50 years of age, and no significant differences were observed in older patients. Hazard ratios (HRs) for patients 35, 40, 45, and 50 years of age were 0.46 (95% confidence interval [CI] = 0.24-0.90), 0.52 (95% CI = 0.29-0.92), 0.58 (95% CI = 0.35-0.95), and 0.64 (95% CI = 0.42-0.99), respectively. Patients with a single metastasis had significantly better survival than those who had 2 to 4 metastases. For distant brain failure, age was a significant effect modifier (P=.043), with similar rates in the 2 arms for patients ≤50 of age; otherwise, the risk was reduced with WBRT for patients >50 years of age. Patients with a single metastasis also had a significantly lower risk of distant brain failure than patients who had 2 to 4 metastases. Local control significantly favored additional WBRT in all age groups. Conclusions: For patients ≤50 years of age, SRS alone favored survival, in addition, the initial omission of WBRT did not impact distant brain relapse rates. SRS alone may be the preferred treatment for this age group

  19. Association Between Radiation Necrosis and Tumor Biology After Stereotactic Radiosurgery for Brain Metastasis

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Jacob A. [Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, Cleveland, Ohio (United States); Bennett, Elizabeth E. [Department of Neurological Surgery, Neurological Institute, Cleveland Clinic, Cleveland, Ohio (United States); Xiao, Roy [Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, Cleveland, Ohio (United States); Kotecha, Rupesh [Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio (United States); Chao, Samuel T. [Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, Cleveland, Ohio (United States); Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio (United States); Rose Ella Burkhardt Brain Tumor and Neuro-Oncology Center, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio (United States); Vogelbaum, Michael A.; Barnett, Gene H.; Angelov, Lilyana [Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, Cleveland, Ohio (United States); Department of Neurological Surgery, Neurological Institute, Cleveland Clinic, Cleveland, Ohio (United States); Rose Ella Burkhardt Brain Tumor and Neuro-Oncology Center, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio (United States); Murphy, Erin S.; Yu, Jennifer S. [Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, Cleveland, Ohio (United States); Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio (United States); Rose Ella Burkhardt Brain Tumor and Neuro-Oncology Center, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio (United States); Ahluwalia, Manmeet S. [Cleveland Clinic Lerner College of Medicine, Cleveland Clinic, Cleveland, Ohio (United States); Rose Ella Burkhardt Brain Tumor and Neuro-Oncology Center, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio (United States); and others

    2016-12-01

    Background: The primary dose-limiting toxicity of stereotactic radiosurgery (SRS) is radiation necrosis (RN), which occurs after approximately 5% to 10% of treatments. This adverse event may worsen neurologic deficits, increase the frequency and cost of imaging, and necessitate prolonged treatment with steroids or antiangiogenic agents. Previous investigations have primarily identified lesion size and dosimetric constraints as risk factors for RN in small populations. We hypothesized that disease histology, receptor status, and mutational status are associated with RN. Methods and Materials: All patients presenting with brain metastasis between 1997 and 2015 who underwent SRS and subsequent radiographic follow-up at a single tertiary-care institution were eligible for inclusion. The primary outcome was the cumulative incidence of radiographic RN. Multivariate competing risks regression was used to identify biological risk factors for RN. Results: 1939 patients (5747 lesions) were eligible for inclusion; 285 patients (15%) experienced radiographic RN after the treatment of 427 (7%) lesions. After SRS, the median time to RN was 7.6 months. After multivariate analysis, graded prognostic assessment, renal pathology, lesion diameter, and the heterogeneity index remained independently predictive of RN in the pooled cohort. In subset analyses of individual pathologies, HER2-amplified status (hazard ratio [HR] 2.05, P=.02), BRAF V600+ mutational status (HR 0.33, P=.04), lung adenocarcinoma histology (HR 1.89, P=.04), and ALK rearrangement (HR 6.36, P<.01) were also associated with RN. Conclusions: In the present investigation constituting the largest series of RN, several novel risk factors were identified, including renal histology, lung adenocarcinoma histology, HER2 amplification, and ALK/BRAF mutational status. These risk factors may be used to guide clinical trial design incorporating biological risk stratification or dose escalation. Future studies determining the

  20. Association Between Radiation Necrosis and Tumor Biology After Stereotactic Radiosurgery for Brain Metastasis

    International Nuclear Information System (INIS)

    Miller, Jacob A.; Bennett, Elizabeth E.; Xiao, Roy; Kotecha, Rupesh; Chao, Samuel T.; Vogelbaum, Michael A.; Barnett, Gene H.; Angelov, Lilyana; Murphy, Erin S.; Yu, Jennifer S.; Ahluwalia, Manmeet S.

    2016-01-01

    Background: The primary dose-limiting toxicity of stereotactic radiosurgery (SRS) is radiation necrosis (RN), which occurs after approximately 5% to 10% of treatments. This adverse event may worsen neurologic deficits, increase the frequency and cost of imaging, and necessitate prolonged treatment with steroids or antiangiogenic agents. Previous investigations have primarily identified lesion size and dosimetric constraints as risk factors for RN in small populations. We hypothesized that disease histology, receptor status, and mutational status are associated with RN. Methods and Materials: All patients presenting with brain metastasis between 1997 and 2015 who underwent SRS and subsequent radiographic follow-up at a single tertiary-care institution were eligible for inclusion. The primary outcome was the cumulative incidence of radiographic RN. Multivariate competing risks regression was used to identify biological risk factors for RN. Results: 1939 patients (5747 lesions) were eligible for inclusion; 285 patients (15%) experienced radiographic RN after the treatment of 427 (7%) lesions. After SRS, the median time to RN was 7.6 months. After multivariate analysis, graded prognostic assessment, renal pathology, lesion diameter, and the heterogeneity index remained independently predictive of RN in the pooled cohort. In subset analyses of individual pathologies, HER2-amplified status (hazard ratio [HR] 2.05, P=.02), BRAF V600+ mutational status (HR 0.33, P=.04), lung adenocarcinoma histology (HR 1.89, P=.04), and ALK rearrangement (HR 6.36, P<.01) were also associated with RN. Conclusions: In the present investigation constituting the largest series of RN, several novel risk factors were identified, including renal histology, lung adenocarcinoma histology, HER2 amplification, and ALK/BRAF mutational status. These risk factors may be used to guide clinical trial design incorporating biological risk stratification or dose escalation. Future studies determining the

  1. Neuroplastic Response After Radiation Therapy for Pediatric Brain Tumors: A Pilot Study

    International Nuclear Information System (INIS)

    Armstrong, Carol L.; Fisher, Michael J.; Li, Yimei; Lustig, Robert A.; Belasco, Jean B.; Minturn, Jane E.; Hill-Kayser, Christine E.; Batra, Sonny; Phillips, Peter C.

    2016-01-01

    Purpose: Clinically effective measurement of cognitive toxicity from photon radiation therapy (XRT) should be accurate, sensitive, and specific. This pilot study tested translational findings on phasic changes in children's memory systems that are sensitive and insensitive to toxic XRT effects to identify a possible neuroplastic effect. Methods and Materials: Memory processes were prospectively tested before XRT and at 3 later time points up to 2 years in 35 children with mixed primary brain tumors who had not experienced recurrence. Memory processes were verbal-semantic, visual-semantic, and visual-perceptual, including accuracy, speed to recall, encoding, retrieval, and recognition. The mixed-effects model included time (to estimate slope), covariates (age, tumor locus, XRT field, and medications) as fixed effects, and individual random intercepts. A sensitivity analysis examined the influence of XRT dose to the hippocampi on memory. Results: Retrieval from long-term verbal-semantic memory declined 2 months after completing XRT, as seen in adults, and was lowest at 1 year, which was delayed in comparison with adults. Double dissociation from visual-perceptual memory at baseline and 2 months was found, consistent with adults. Recovery was demonstrated 2 years after XRT. Patterns were unchanged when dose to hippocampus was included in the model. Conclusions: Verbal and semantic long-term retrieval is specifically sensitive to XRT-related cognitive dysfunction, without effect on visual-perceptual memory. Children reached nadir in XRT-sensitive memory 1 year after XRT and recovered by 2 years, which is later than that observed in adults. The protracted period of post-XRT injury may represent the maturation of the human hippocampus and white matter into late adolescence.

  2. Neuroplastic Response After Radiation Therapy for Pediatric Brain Tumors: A Pilot Study

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Carol L., E-mail: armstrongc@email.chop.edu [Neuro-Oncology Section, Children' s Hospital of Philadelphia, and Department of Pediatrics, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Fisher, Michael J. [Neuro-Oncology Section, Children' s Hospital of Philadelphia, and Department of Pediatrics, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Li, Yimei [Oncology Division, Children' s Hospital of Philadelphia, and Department of Biostatistics and Epidemiology, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Lustig, Robert A. [Department of Radiation Oncology, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Belasco, Jean B.; Minturn, Jane E. [Neuro-Oncology Section, Children' s Hospital of Philadelphia, and Department of Pediatrics, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Hill-Kayser, Christine E.; Batra, Sonny [Department of Radiation Oncology, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Phillips, Peter C. [Neuro-Oncology Section, Children' s Hospital of Philadelphia, and Department of Pediatrics, The Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania (United States)

    2016-07-01

    Purpose: Clinically effective measurement of cognitive toxicity from photon radiation therapy (XRT) should be accurate, sensitive, and specific. This pilot study tested translational findings on phasic changes in children's memory systems that are sensitive and insensitive to toxic XRT effects to identify a possible neuroplastic effect. Methods and Materials: Memory processes were prospectively tested before XRT and at 3 later time points up to 2 years in 35 children with mixed primary brain tumors who had not experienced recurrence. Memory processes were verbal-semantic, visual-semantic, and visual-perceptual, including accuracy, speed to recall, encoding, retrieval, and recognition. The mixed-effects model included time (to estimate slope), covariates (age, tumor locus, XRT field, and medications) as fixed effects, and individual random intercepts. A sensitivity analysis examined the influence of XRT dose to the hippocampi on memory. Results: Retrieval from long-term verbal-semantic memory declined 2 months after completing XRT, as seen in adults, and was lowest at 1 year, which was delayed in comparison with adults. Double dissociation from visual-perceptual memory at baseline and 2 months was found, consistent with adults. Recovery was demonstrated 2 years after XRT. Patterns were unchanged when dose to hippocampus was included in the model. Conclusions: Verbal and semantic long-term retrieval is specifically sensitive to XRT-related cognitive dysfunction, without effect on visual-perceptual memory. Children reached nadir in XRT-sensitive memory 1 year after XRT and recovered by 2 years, which is later than that observed in adults. The protracted period of post-XRT injury may represent the maturation of the human hippocampus and white matter into late adolescence.

  3. Effect of edaravone on radiation-induced brain necrosis in patients with nasopharyngeal carcinoma after radiotherapy: a randomized controlled trial.

    Science.gov (United States)

    Tang, Yamei; Rong, Xiaoming; Hu, Weihan; Li, Guoqian; Yang, Xiaoxia; Yang, Jianhua; Xu, Pengfei; Luo, Jinjun

    2014-11-01

    Excessive generation of free radicals plays a critical role in the pathogenesis of radiation-induced brain injury. This study was designed to evaluate the protective effect of edaravone, a free radical scavenger, on radiation-induced brain necrosis in patients with nasopharyngeal carcinoma. Eligible patients were randomized 1:1 to the control group and the edaravone group (intravenous 30 mg twice per day for 2 weeks). Both groups received intravenous conventional steroid therapy and were monitored by brain MRI and LENT/SOMA scales prior to the entry of the trial and at 3-months after completing the trial. The primary end point was a 3-month response rate of the proportional changes determined by MRI. The trial is registered at Clinicaltrials.gov Identifier: NCT01865201. Between 2009 and 2012, we enrolled 154 patients. Of whom 137 were eligible for analysis. The volumes of necrosis estimated on T(2)-weighted image showed that 55.6 % edaravone-treated patients (40 out of 72) showed edema decreases ≥25 %, which was significantly higher than that in the control group (35.4 %, 23 out of 65, p = 0.025). Forty-four patients treated with edaravone (61.1 %) reported improvement in neurologic symptoms and signs evaluated by LENT/SOMA scales, while the rate was 38.5 % in the control group (p = 0.006). MRI of the edaravone group showed a significant decrease in area of T(1)-weighted contrast enhancement (1.67 ± 4.69 cm(2), p = 0.004) and the T(2)-weighted edema (5.08 ± 10.32 cm(2), p = 0.000). Moreover, compared with those in control group, patients with edaravone exhibited significantly better radiological improvement measured by T(2)-weighted image (p = 0.042). Administration of edaravone, in adjunct to steroid regimen, might provide a better outcome in patients with radiation-induced brain necrosis.

  4. Evaluation of the reconstruction method and effect of partial volume in brain scintiscanning; Avaliacao do metodo de reconstrucao e efeito do volume parcial em cintilografia cerebral

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, Monica Araujo

    2016-10-01

    Alzheimer's disease is a neurodegenerative disorder, on which occurs a progressive and irreversible destruction of neurons. According to the World Health Organization (WHO) 35.6 million people are living with dementia, being recommended that governments prioritize early diagnosis techniques. Laboratory and psychological tests for cognitive assessment are conducted and further complemented by neurological imaging from nuclear medicine exams in order to establish an accurate diagnosis. The image quality evaluation and reconstruction process effects are important tools in clinical routine. In the present work, these quality parameters were studied, and the effects of partial volume (PVE) for lesions of different sizes and geometries that are attributed to the limited resolution of the equipment. In dementia diagnosis, this effect can be confused with intake losses due to cerebral cortex atrophy. The evaluation was conducted by two phantoms of different shapes as suggested by (a) American College of Radiology (ACR) and (b) National Electrical Manufacturers Association (NEMA) for Contrast, Contrast-to-Noise Ratio (CNR) and Recovery Coefficient (RC) calculation versus lesions shape and size. Technetium-99m radionuclide was used in a local brain scintigraphy protocol, for proportions lesion to background of 2:1, 4:1, 6:1, 8:1 and 10:1. Fourteen reconstruction methods were used for each concentration applying different filters and algorithms. Before the analysis of all image properties, the conclusion is that the predominant effect is the partial volume, leading to errors of measurement of more than 80%. Furthermore, it was demonstrate that the most effective method of reconstruction is FBP with Metz filter, providing better contrast and contrast to noise ratio results. In addition, this method shows the best Recovery Coefficients correction for each lesion. The ACR phantom showed the best results assigned to a more precise reconstruction of a cylinder, which does not

  5. A Comparison of Locomotor Therapy Interventions: Partial-Body Weight-Supported Treadmill, Lokomat, and G-EO Training in People With Traumatic Brain Injury.

    Science.gov (United States)

    Esquenazi, Alberto; Lee, Stella; Wikoff, Amanda; Packel, Andrew; Toczylowski, Theresa; Feeley, John

    2017-09-01

    Literature in the application of gait training techniques in persons with traumatic brain injury (TBI) is limited. Current techniques require multiple staff and are physically demanding. The use of a robotic locomotor training may provide improved training capacity for this population. To examine the impact of 3 different modes of locomotor therapy on gait velocity and spatiotemporal symmetry using an end effector robot (G-EO); a robotic exoskeleton (Lokomat), and manual assisted partial-body weight-supported treadmill training (PBWSTT) in participants with traumatic brain injury. Randomized, prospective study. Tertiary rehabilitation hospital. A total of 22 individuals with ≥12 months chronic TBI with hemiparetic pattern able to walk overground without assistance at velocities between 0.2 and 0.6 m/s. Eighteen sessions of 45 minutes of assigned locomotor training. Overground walking self-selected velocity (SSV), maximal velocity (MV), spatiotemporal asymmetry ratio, 6-Minute Walk Test (6MWT), and mobility domain of Stroke Impact Scale (MSIS). Severity in walking dysfunction was similar across groups as determined by walking velocity data. At baseline, participants in the Lokomat group had a baseline velocity that was slightly slower compared with the other groups. Training elicited a statistically significant median increase in SSV for all groups compared with pretraining (Lokomat, P = .04; G-EO, P = .03; and PBWSTT, P = .02) and MV excluding the G-EO group (Lokomat, P = .04; PBWSTT, P = .03 and G-EO, P = .15). There were no pre-post significant differences in swing time, stance time, and step length asymmetry ratios at SSV or MV for any of the interventions. Mean rank in the change of SSV and MV was not statistically significantly different between groups. Participants in the G-EO and PBWSTT groups significantly improved their 6MWT posttraining (P = .04 and .03, respectively). The MSIS significantly improved only for the Lokomat group (P = .04 and .03). The

  6. Evaluation of Partial Breast Reirradiation with Intraoperative Radiotherapy after Prior Thoracic Radiation: A Single-Institution Report of Outcomes and Toxicity

    Directory of Open Access Journals (Sweden)

    Christine Chin

    2017-08-01

    Full Text Available IntroductionMastectomy is the current standard of care for ipsilateral breast tumor recurrences after prior whole breast irradiation (WBI. We report our single-institution experience with breast-conserving surgery (BCS followed by intraoperative radiotherapy (IORT as an alternative to salvage mastectomy for new or recurrent breast cancers that develop in the setting of prior thoracic radiation.MethodsWe performed an IRB-approved retrospective review of patients treated with breast IORT between September 2013 and November 2016. We identified 12 patients who declined salvage mastectomy for their breast cancer after prior thoracic radiation. IORT was delivered using the Intrabeam™ device (Carl Zeiss, Germany. A dose of 20 Gy was prescribed to the lumpectomy cavity surface using 50 kV X-rays. We graded both acute and late treatment-related breast toxicities using the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. Local control, mastectomy-free survival, distant metastasis, and overall survival were determined.ResultsOur study included nine patients who developed a new or recurrent ipsilateral breast cancer after prior WBI for early-stage breast cancer, two patients with primary breast cancer after mantle-field radiation for Hodgkin’s lymphoma, and one patient with a synchronous stage III non-small cell lung cancer treated with definitive radiation to the ipsilateral lung and mediastinum. The median time from prior radiation to presentation was 18 years (range: 2 months to 46 years. All patients successfully underwent partial breast reirradiation with IORT and were able to preserve their breast. At a median follow-up of 14 months (4–25 months, there were no local or distant recurrences. There was a single non-cancer-related death. In the acute setting, we observed grade 1 toxicity in 58% (n = 7, grade 2 toxicity in 17% (n = 2, and no grade 3 or higher toxicity. In the late setting, at

  7. Selective brain lesions reduce morphine- and radiation-induced locomotor hyperactivity of the C57BL/6J mouse

    International Nuclear Information System (INIS)

    Mickley, G.A.; Stevens, K.E.; White, G.A.; Gibbs, G.L.

    1984-01-01

    The apparent resemblance between the stereotypic locomotor hyperactivity observed after either an injection of morphine or irradiation of the C57BL/6J mouse has suggested the possibility of similar biochemical and neuroanatomical substrates of these behaviors. In this study the authors made selective brain lesions in an attempt to reverse the locomotor response observed after morphine (30 mg/kg) or radiation (1500 rads /sup 60/Co) treatments. Lesions impinging on both the dorso-medial caudate and lateral septal nuclei caused a significant decrease in morphine-induced and radiogenic locomotion. Lesions of the individual brain areas did not significantly alter the opiate locomotor response. This reduction in locomotion could not be attributed to a generalized post-surgical lethargy since other brain lesions of similar size did not significantly suppress these behaviors. These data suggest the possibility of some common central nervous system mechanisms which may support the stereotypic locomotor hyperactivity observed in the C57BL/6J mouse after either morphine or radiation treatment

  8. Experimental study of Gadofluorine M enhancement in early diagnosis of radiation brain injury by MRI in rats

    International Nuclear Information System (INIS)

    Bai Shoumin; Liao Chengde; Guo Ruomi; Huang Ying; Liang Biling; Shen Jun; Lu Taixiang

    2011-01-01

    Objective: To explore the value of Gadofluorine M, a novel MRI enhancement agent,in the diagnosis the early radiation brain injury. Methods: Seventy-two Wistar rats were randomly divided into 5 equal groups. To establish the radiation injury model, the rat's posterior brain was irradiated with 0 (blank controls), 25, 35, 45, 55, and 65 Gy, respectively. After irradiation MR plain scanning and Gadofluorine M enhancement scanning (after the T1WI and T2WI scanning Gf at the dosage of 0.1 mmol/kg was injected intravenously and scanning was performed again 12 h later) were performed once a week for 8 weeks. Another 12 rats were randomly divided into 2 equal groups to exposure to 55 and 65 Gy, respectively, and MR scanning was performed once a week for 8 weeks since the third week after MR. After T1WI and T2WI scanning Gd-DTPA was injected intravenously, MR was conducted again 30 min later, and Gf was injected intravenously (Gd-DTPA enhancement and Gf enhancement contrast). The MR image and the pixel count were compared. Since the third week 2 rats from the Gf enhancement scanning group and 1 rat from the Gd-DTPA enhancement and Gf enhancement contrast were killed after MR with their brains taken out to undergo pathological examination. Results: No abnormal signal changes were found in MRI in 25 and 35 Gy groups within 2 months after irradiation. A high signal in the Gf enhancement T1WI image was found in 45, 55, and 65 Gy groups within the period of 4-6 weeks after radiation. The signal intensity was significantly higher than that of the control, 25, and 35 Gy groups (F=2.15, P<0.05). The emerge time of this signal was negatively correlated with the dose of radiation (r =-0.62, P<0.05). When there was no obvious change was found by Gd-DTPA enhancement, a high signal representing change of injury could be found in Gf enhancement in the same rat. The signal intensity was significantly enhanced in Gf enhancement compared to the Gd-DTPA enhancement (F=2.74, P<0

  9. Mitigation by Aloe Vera of cadmium chloride and radiation induced biochemical changes in the brain of Swiss albino mice

    International Nuclear Information System (INIS)

    Chakrawarti, Aruna; Kanwar, Om; Nayak, Kamal Kumar; Ranga, Deepti; Jangir, Ashok; Ram, Purkha

    2013-01-01

    Whole body exposure to ionizing radiation provokes oxidative damage, organ dysfunction and metabolic disturbance. Herbal drugs offer an alternative to the synthetic radioprotective compounds which are either non-toxic or less toxic. Aloe vera rich in polyphenolic compound is known to possess antioxidant properties. In the context, the present study, effect of Aloe vera against radiation and cadmium induced changes in the brain of Swiss albino mice. For the purpose, six to eight weeks old male Swiss albino mice were selected and divided into seven groups:- Group I (Sham-irradiated), Group II (treated with cadmium chloride 20 ppm), Group III (Irradiated with 7.0 Gy gamma rays), Group IV (Both irradiated and treated with cadmium chloride solution), Group V (Cadmium and Aloe vera treated), Group VI (radiation and Aloe vera treated), Group VII (radiation, and cadmium chloride and Aloe vera treated). The animals were sacrificed by cervical dislocation at each post-treatment intervals of 1, 2, 4, 7, 14 and 28 days. The brain (cerebral cortex) was taken out and quantitatively analyzed for different biochemical parameters such as total proteins, glycogen, cholesterol, acid phosphatase activity, alkaline phosphatase activity, DNA and RNA. The value of cholesterol, glycogen, RNA, acid phosphatase activity, and alkaline phosphatase activity increased up to day-14 in non drug-treated groups and day-7 in Aloe vera treated groups and thereafter decreased up to day-28. The value of total proteins and DNA decreased up to day-14 in non drug-treated groups and day-7 in the drug treated groups then increased in all groups. In only cadmium chloride (Without and with drug) treated animals (Groups II and V) the value of cholesterol decreased during early intervals (days-14 and 7 respectively) and increased thereafter. Severe changes were observed after combined exposure to radiation and cadmium chloride showing synergistic effect. Aloe vera reduced the severity of damage and made the

  10. Neuroimaging and neuropsychological follow-up study in a pediatric brain tumor patient treated with surgery and radiation.

    Science.gov (United States)

    Schmidt, Adam T; Martin, Rebecca B; Ozturk, Arzu; Kates, Wendy R; Wharam, Moody D; Mahone, E Mark; Horska, Alena

    2010-02-01

    Intracranial tumors are the most common neoplasms of childhood, accounting for approximately 20% of all pediatric malignancies. Radiation therapy has led directly to significant increases in survival of children with certain types of intracranial tumors; however, given the aggressive nature of this therapy, children are at risk for exhibiting changes in brain structure, neuronal biochemistry, and neurocognitive functioning. In this case report, we present neuropsychological, magnetic resonance imaging, proton magnetic resonance spectroscopic imaging, and diffusion tensor imaging data for two adolescents (one patient with ependymal spinal cord tumor with intracranial metastases, and one healthy, typically developing control) from three time points as defined by the patient's radiation schedule (baseline before the patient's radiation therapy, 6 months following completion of the patient's radiation, and 27 months following the patient's radiation). In the patient, there were progressive decreases in gray and white matter volumes as well as early decreases in mean N-acetyl aspartate/choline (NAA/Cho) ratios and fractional anisotropy (FA) in regions with normal appearance on conventional MRI. At the last follow-up, NAA/Cho and FA tended to change in the direction to normal values in selected regions. At the same time, the patient had initial reduction in language and motor skills, followed by return to baseline, but later onset delay in visuospatial and visual perceptual skills. Results are discussed in terms of sensitivity of the four techniques to early and late effects of treatment, and avenues for future investigations.

  11. Early brain response to low-dose radiation exposure involves molecular networks and pathways associated with cognitive functions, advanced aging and Alzheimer's disease.

    Science.gov (United States)

    Lowe, Xiu R; Bhattacharya, Sanchita; Marchetti, Francesco; Wyrobek, Andrew J

    2009-01-01

    Understanding the cognitive and behavioral consequences of brain exposures to low-dose ionizing radiation has broad relevance for health risks from medical radiation diagnostic procedures, radiotherapy and environmental nuclear contamination as well as for Earth-orbit and space missions. Analyses of transcriptome profiles of mouse brain tissue after whole-body irradiation showed that low-dose exposures (10 cGy) induced genes not affected by high-dose radiation (2 Gy) and that low-dose genes were associated with unique pathways and functions. The low-dose response had two major components: pathways that are consistently seen across tissues and pathways that were specific for brain tissue. Low-dose genes clustered into a saturated network (P < 10(-53)) containing mostly down-regulated genes involving ion channels, long-term potentiation and depression, vascular damage, etc. We identified nine neural signaling pathways that showed a high degree of concordance in their transcriptional response in mouse brain tissue after low-dose irradiation, in the aging human brain (unirradiated), and in brain tissue from patients with Alzheimer's disease. Mice exposed to high-dose radiation did not show these effects and associations. Our findings indicate that the molecular response of the mouse brain within a few hours after low-dose irradiation involves the down-regulation of neural pathways associated with cognitive dysfunctions that are also down-regulated in normal human aging and Alzheimer's disease.

  12. Radiation

    International Nuclear Information System (INIS)

    2013-01-01

    The chapter one presents the composition of matter and atomic theory; matter structure; transitions; origin of radiation; radioactivity; nuclear radiation; interactions in decay processes; radiation produced by the interaction of radiation with matter

  13. Radiation-induced temporary partial epilation in the pig: a biological indicator of radiation dose and dose distribution to the skin

    International Nuclear Information System (INIS)

    Sieber, V.K.; Hopewell, J.W.

    1990-01-01

    Radiation damage to the matrix cells of actively growing hairs can result in transient epilation in the pig, the severity of which can be assessed using a visual scoring system. The extent of hair loss was found to be dose-dependent for single doses in the range 6 - 14 Gy for 250 kV X rays. The ED 50 for detectable hair loss was 9.83 ± 0.58 Gy whilst that for the loss of > 50% of hairs was 13.78 ± 0.90 Gy. The system is simple, non-invasive and would appear to have considerable potential for use in biological dosimetry for high exposures that are likely to require local treatment. (author)

  14. Relation between radiation-induced whole lung functional loss and regional structural changes in partial irradiated rat lung

    International Nuclear Information System (INIS)

    Luijk, Peter van; Novakova-Jiresova, Alena; Faber, Hette; Steneker, Marloes N.J.; Kampinga, Harm H.; Meertens, Haarm; Coppes, Robert P.

    2006-01-01

    Purpose: Radiation-induced pulmonary toxicity is characterized by dose, region, and time-dependent severe changes in lung morphology and function. This study sought to determine the relation between the structural and functional changes in the irradiated rat lung at three different phases after irradiation. Materials and Methods: Six groups of animals were irradiated to 16-22 Gy to six different lung regions, each containing 50% of the total lung volume. Before and every 2 weeks after irradiation, the breathing rate (BR) was measured, and at Weeks 8, 26, and 38 CT was performed. From the computed tomography scans, the irradiated lung tissue was delineated using a computerized algorithm. A single quantitative measure for structural change was derived from changes of the mean and standard deviation of the density within the delineated lung. Subsequently, this was correlated with the BR in the corresponding phase. Results: In the mediastinal and apex region, the BR and computed tomography density changes did not correlate in any phase. After lateral irradiation, the density changes always correlated with the BR; however, in all other regions, the density changes only correlated significantly (r 2 = 0.46-0.85, p < 0.05) with the BR in Week 26. Conclusion: Changes in pulmonary function correlated with the structural changes in the absence of confounding heart irradiation

  15. [Effect of Low-Intensity 900 MHz Frequency Electromagnetic Radiation on Rat Brain Enzyme Activities Linked to Energy Metabolism].

    Science.gov (United States)

    Petrosyan, M S; Nersesova, L S; Gazaryants, M G; Meliksetyan, G O; Malakyan, M G; Bajinyan, S A; Akopian, J I

    2015-01-01

    The research deals with the effect of low-intensity 900 MHz frequency electromagnetic radiation (EMR), power density 25 μW/cm2, on the following rat brain and blood serum enzyme activities: creatine kinase (CK), playing a central role in the process of storing and distributing the cell energy, as well as alanine aminotransferase (ALT) and aspartate aminotransferase (AST) that play a key role in providing the conjunction of carbohydrate and amino acid metabolism. The comparative analysis of the changes in the enzyme activity studied at different times following the two-hour single, as well as fractional, radiation equivalent of the total time showed that the most radiosensitive enzyme is the brain creatine kinase, which may then be recommended as a marker of the radio frequency radiation impact. According to the analysis of the changing dynamics of the CK, ALT and AST activity level, with time these changes acquire the adaptive character and are directed to compensate the damaged cell energy metabolism.

  16. [Formula: see text]Working memory and attention in pediatric brain tumor patients treated with and without radiation therapy.

    Science.gov (United States)

    Raghubar, Kimberly P; Mahone, E Mark; Yeates, Keith Owen; Cecil, Kim M; Makola, Monwabisi; Ris, M Douglas

    2017-08-01

    Children are at risk for cognitive difficulties following the diagnosis and treatment of a brain tumor. Longitudinal studies have consistently demonstrated declines on measures of intellectual functioning, and recently it has been proposed that specific neurocognitive processes underlie these changes, including working memory, processing speed, and attention. However, a fine-grained examination of the affected neurocognitive processes is required to inform intervention efforts. Radiation therapy (RT) impacts white matter integrity, likely affecting those cognitive processes supported by distributed neural networks. This study examined working memory and attention in children during the early delayed stages of recovery following surgical resection and RT. The participants included 27 children diagnosed with pediatric brain tumor, treated with (n = 12) or without (n = 15) RT, who completed experimental and standardized measures of working memory and attention (n-back and digit span tasks). Children treated with radiation performed less well than those who did not receive radiation on the n-back measure, though performance at the 0-back level was considerably poorer than would be expected for both groups, perhaps suggesting difficulties with more basic processes such as vigilance. Along these lines, marginal differences were noted on digit span forward. The findings are discussed with respect to models of attention and working memory, and the interplay between the two.

  17. Preliminary Results of a Phase 1 Dose-Escalation Trial for Early-Stage Breast Cancer Using 5-Fraction Stereotactic Body Radiation Therapy for Partial-Breast Irradiation

    International Nuclear Information System (INIS)

    Rahimi, Asal; Thomas, Kimberly; Spangler, Ann; Rao, Roshni; Leitch, Marilyn; Wooldridge, Rachel; Rivers, Aeisha; Seiler, Stephen; Albuquerque, Kevin; Stevenson, Stella; Goudreau, Sally; Garwood, Dan; Haley, Barbara; Euhus, David; Heinzerling, John; Ding, Chuxiong; Gao, Ang; Ahn, Chul; Timmerman, Robert

    2017-01-01

    Purpose: To evaluate the tolerability of a dose-escalated 5-fraction stereotactic body radiation therapy for partial-breast irradiation (S-PBI) in treating early-stage breast cancer after partial mastectomy; the primary objective was to escalate dose utilizing a robotic stereotactic radiation system treating the lumpectomy cavity without exceeding the maximum tolerated dose. Methods and Materials: Eligible patients included those with ductal carcinoma in situ or invasive nonlobular epithelial histologies and stage 0, I, or II, with tumor size <3 cm. Patients and physicians completed baseline and subsequent cosmesis outcome questionnaires. Starting dose was 30 Gy in 5 fractions and was escalated by 2.5 Gy total for each cohort to 40 Gy. Results: In all, 75 patients were enrolled, with a median age of 62 years. Median follow-up for 5 cohorts was 49.9, 42.5, 25.7, 20.3, and 13.5 months, respectively. Only 3 grade 3 toxicities were experienced. There was 1 dose-limiting toxicity in the overall cohort. Ten patients experienced palpable fat necrosis (4 of which were symptomatic). Physicians scored cosmesis as excellent or good in 95.9%, 100%, 96.7%, and 100% at baseline and 6, 12, and 24 months after S-PBI, whereas patients scored the same periods as 86.5%, 97.1%, 95.1%, and 95.3%, respectively. The disagreement rates between MDs and patients during those periods were 9.4%, 2.9%, 1.6%, and 4.7%, respectively. There have been no recurrences or distant metastases. Conclusion: Dose was escalated to the target dose of 40 Gy in 5 fractions, with the occurrence of only 1 dose-limiting toxicity. Patients felt cosmetic results improved within the first year after surgery and stereotactic body radiation therapy. Our results show minimal toxicity with excellent cosmesis; however, further follow-up is warranted in future studies. This study is the first to show the safety, tolerability, feasibility, and cosmesis results of a 5-fraction dose-escalated S-PBI treatment for

  18. Preliminary Results of a Phase 1 Dose-Escalation Trial for Early-Stage Breast Cancer Using 5-Fraction Stereotactic Body Radiation Therapy for Partial-Breast Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Rahimi, Asal, E-mail: asal.rahimi@utsouthwestern.edu [University of Texas Southwestern Medical Center, Dallas, Texas (United States); Thomas, Kimberly; Spangler, Ann [University of Texas Southwestern Medical Center, Dallas, Texas (United States); Rao, Roshni; Leitch, Marilyn; Wooldridge, Rachel; Rivers, Aeisha [Department of Surgery, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Seiler, Stephen [Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Albuquerque, Kevin; Stevenson, Stella [University of Texas Southwestern Medical Center, Dallas, Texas (United States); Goudreau, Sally [Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Garwood, Dan [University of Texas Southwestern Medical Center, Dallas, Texas (United States); Haley, Barbara [Department of Medical Oncology, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Euhus, David [Department of Surgery, Johns Hopkins University, Baltimore, Maryland (United States); Heinzerling, John [Department of Radiation Oncology, Levine Cancer Institute, Charlotte, North Carolina (United States); Ding, Chuxiong [University of Texas Southwestern Medical Center, Dallas, Texas (United States); Gao, Ang; Ahn, Chul [Department of Statistics, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Timmerman, Robert [University of Texas Southwestern Medical Center, Dallas, Texas (United States)

    2017-05-01

    Purpose: To evaluate the tolerability of a dose-escalated 5-fraction stereotactic body radiation therapy for partial-breast irradiation (S-PBI) in treating early-stage breast cancer after partial mastectomy; the primary objective was to escalate dose utilizing a robotic stereotactic radiation system treating the lumpectomy cavity without exceeding the maximum tolerated dose. Methods and Materials: Eligible patients included those with ductal carcinoma in situ or invasive nonlobular epithelial histologies and stage 0, I, or II, with tumor size <3 cm. Patients and physicians completed baseline and subsequent cosmesis outcome questionnaires. Starting dose was 30 Gy in 5 fractions and was escalated by 2.5 Gy total for each cohort to 40 Gy. Results: In all, 75 patients were enrolled, with a median age of 62 years. Median follow-up for 5 cohorts was 49.9, 42.5, 25.7, 20.3, and 13.5 months, respectively. Only 3 grade 3 toxicities were experienced. There was 1 dose-limiting toxicity in the overall cohort. Ten patients experienced palpable fat necrosis (4 of which were symptomatic). Physicians scored cosmesis as excellent or good in 95.9%, 100%, 96.7%, and 100% at baseline and 6, 12, and 24 months after S-PBI, whereas patients scored the same periods as 86.5%, 97.1%, 95.1%, and 95.3%, respectively. The disagreement rates between MDs and patients during those periods were 9.4%, 2.9%, 1.6%, and 4.7%, respectively. There have been no recurrences or distant metastases. Conclusion: Dose was escalated to the target dose of 40 Gy in 5 fractions, with the occurrence of only 1 dose-limiting toxicity. Patients felt cosmetic results improved within the first year after surgery and stereotactic body radiation therapy. Our results show minimal toxicity with excellent cosmesis; however, further follow-up is warranted in future studies. This study is the first to show the safety, tolerability, feasibility, and cosmesis results of a 5-fraction dose-escalated S-PBI treatment for

  19. Image Guided Radiation Therapy Using Synthetic Computed Tomography Images in Brain Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Price, Ryan G. [Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan (United States); Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan (United States); Kim, Joshua P.; Zheng, Weili [Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan (United States); Chetty, Indrin J. [Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan (United States); Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan (United States); Glide-Hurst, Carri, E-mail: churst2@hfhs.org [Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan (United States); Department of Radiation Oncology, Wayne State University School of Medicine, Detroit, Michigan (United States)

    2016-07-15

    Purpose: The development of synthetic computed tomography (CT) (synCT) derived from magnetic resonance (MR) images supports MR-only treatment planning. We evaluated the accuracy of synCT and synCT-generated digitally reconstructed radiographs (DRRs) relative to CT and determined their performance for image guided radiation therapy (IGRT). Methods and Materials: Magnetic resonance simulation (MR-SIM) and CT simulation (CT-SIM) images were acquired of an anthropomorphic skull phantom and 12 patient brain cancer cases. SynCTs were generated using fluid attenuation inversion recovery, ultrashort echo time, and Dixon data sets through a voxel-based weighted summation of 5 tissue classifications. The DRRs were generated from the phantom synCT, and geometric fidelity was assessed relative to CT-generated DRRs through bounding box and landmark analysis. An offline retrospective analysis was conducted to register cone beam CTs (n=34) to synCTs and CTs using automated rigid registration in the treatment planning system. Planar MV and KV images (n=37) were rigidly registered to synCT and CT DRRs using an in-house script. Planar and volumetric registration reproducibility was assessed and margin differences were characterized by the van Herk formalism. Results: Bounding box and landmark analysis of phantom synCT DRRs were within 1 mm of CT DRRs. Absolute planar registration shift differences ranged from 0.0 to 0.7 mm for phantom DRRs on all treatment platforms and from 0.0 to 0.4 mm for volumetric registrations. For patient planar registrations, the mean shift differences were 0.4 ± 0.5 mm (range, −0.6 to 1.6 mm), 0.0 ± 0.5 mm (range, −0.9 to 1.2 mm), and 0.1 ± 0.3 mm (range, −0.7 to 0.6 mm) for the superior-inferior (S-I), left-right (L-R), and anterior-posterior (A-P) axes, respectively. The mean shift differences in volumetric registrations were 0.6 ± 0.4 mm (range, −0.2 to 1.6 mm), 0.2 ± 0.4 mm (range, −0.3 to 1.2 mm), and 0.2 ± 0

  20. Image Guided Radiation Therapy Using Synthetic Computed Tomography Images in Brain Cancer

    International Nuclear Information System (INIS)

    Price, Ryan G.; Kim, Joshua P.; Zheng, Weili; Chetty, Indrin J.; Glide-Hurst, Carri

    2016-01-01

    Purpose: The development of synthetic computed tomography (CT) (synCT) derived from magnetic resonance (MR) images supports MR-only treatment planning. We evaluated the accuracy of synCT and synCT-generated digitally reconstructed radiographs (DRRs) relative to CT and determined their performance for image guided radiation therapy (IGRT). Methods and Materials: Magnetic resonance simulation (MR-SIM) and CT simulation (CT-SIM) images were acquired of an anthropomorphic skull phantom and 12 patient brain cancer cases. SynCTs were generated using fluid attenuation inversion recovery, ultrashort echo time, and Dixon data sets through a voxel-based weighted summation of 5 tissue classifications. The DRRs were generated from the phantom synCT, and geometric fidelity was assessed relative to CT-generated DRRs through bounding box and landmark analysis. An offline retrospective analysis was conducted to register cone beam CTs (n=34) to synCTs and CTs using automated rigid registration in the treatment planning system. Planar MV and KV images (n=37) were rigidly registered to synCT and CT DRRs using an in-house script. Planar and volumetric registration reproducibility was assessed and margin differences were characterized by the van Herk formalism. Results: Bounding box and landmark analysis of phantom synCT DRRs were within 1 mm of CT DRRs. Absolute planar registration shift differences ranged from 0.0 to 0.7 mm for phantom DRRs on all treatment platforms and from 0.0 to 0.4 mm for volumetric registrations. For patient planar registrations, the mean shift differences were 0.4 ± 0.5 mm (range, −0.6 to 1.6 mm), 0.0 ± 0.5 mm (range, −0.9 to 1.2 mm), and 0.1 ± 0.3 mm (range, −0.7 to 0.6 mm) for the superior-inferior (S-I), left-right (L-R), and anterior-posterior (A-P) axes, respectively. The mean shift differences in volumetric registrations were 0.6 ± 0.4 mm (range, −0.2 to 1.6 mm), 0.2 ± 0.4 mm (range, −0.3 to 1.2 mm), and 0.2 ± 0

  1. SU-E-T-589: Optimization of Patient Head Angle Position to Spare Hippocampus During the Brain Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Cheon, G; Kang, Y [Radiation Oncology, Seoul St. Mary’s Hospital, Seoul (Korea, Republic of); Kang, S; Kim, T; Kim, D; Suh, T [The Catholic University of Korea, Seoul (Korea, Republic of)

    2015-06-15

    Purpose: Hippocampus is one of the important organs which controls emotions, behaviors, movements the memorizing and learning ability. In the conventional head & neck therapy position, it is difficult to perform the hippocampal-sparing brain radiation therapy. The purpose of this study is to investigate optimal head angle which can save the hippocampal-sparing and organ at risk (OAR) in conformal radiation therapy (CRT), Intensity modulation radiation therapy (IMRT) and helical tomotherapy (HT). Methods: Three types of radiation treatment plans, CRT, IMRT and Tomotherapy plans, were performed for 10 brain tumor patients. The image fusion between CT and MRI data were used in the contour due to the limited delineation of the target and OAR in the CT scan. The optimal condition plan was determined by comparing the dosimetric performance of the each plan with the use of various parameters which include three different techniques (CRT, IMRT, HT) and 4 angle (0, 15, 30, 40 degree). The each treatment plans of three different techniques were compared with the following parameters: conformity index (CI), homogeneity index (HI), target coverage, dose in the OARs, monitor units (MU), beam on time and the normal tissue complication probability (NTCP). Results: HI, CI and target coverage was most excellent in head angle 30 degree among all angle. When compared by modality, target coverage and CI showed good results in IMRT and TOMO than compared to the CRT. HI at the head angle 0 degrees is 1.137±0.17 (CRT), 1.085±0.09 (IMRT) and 1.077±0.06 (HT). HI at the head angle 30 degrees is 1.056±0.08 (CRT), 1.020±0.05 (IMRT) and 1.022±0.07 (HT). Conclusion: The results of our study show that when head angle tilted at 30 degree, target coverage, HI, CI were improved, and the dose delivered to OAR was reduced compared with conventional supine position in brain radiation therapy. This work was supported by the Radiation Technology R&D program (No. 2013M2A2A7043498) and the Mid

  2. SU-E-T-589: Optimization of Patient Head Angle Position to Spare Hippocampus During the Brain Radiation Therapy

    International Nuclear Information System (INIS)

    Cheon, G; Kang, Y; Kang, S; Kim, T; Kim, D; Suh, T

    2015-01-01

    Purpose: Hippocampus is one of the important organs which controls emotions, behaviors, movements the memorizing and learning ability. In the conventional head & neck therapy position, it is difficult to perform the hippocampal-sparing brain radiation therapy. The purpose of this study is to investigate optimal head angle which can save the hippocampal-sparing and organ at risk (OAR) in conformal radiation therapy (CRT), Intensity modulation radiation therapy (IMRT) and helical tomotherapy (HT). Methods: Three types of radiation treatment plans, CRT, IMRT and Tomotherapy plans, were performed for 10 brain tumor patients. The image fusion between CT and MRI data were used in the contour due to the limited delineation of the target and OAR in the CT scan. The optimal condition plan was determined by comparing the dosimetric performance of the each plan with the use of various parameters which include three different techniques (CRT, IMRT, HT) and 4 angle (0, 15, 30, 40 degree). The each treatment plans of three different techniques were compared with the following parameters: conformity index (CI), homogeneity index (HI), target coverage, dose in the OARs, monitor units (MU), beam on time and the normal tissue complication probability (NTCP). Results: HI, CI and target coverage was most excellent in head angle 30 degree among all angle. When compared by modality, target coverage and CI showed good results in IMRT and TOMO than compared to the CRT. HI at the head angle 0 degrees is 1.137±0.17 (CRT), 1.085±0.09 (IMRT) and 1.077±0.06 (HT). HI at the head angle 30 degrees is 1.056±0.08 (CRT), 1.020±0.05 (IMRT) and 1.022±0.07 (HT). Conclusion: The results of our study show that when head angle tilted at 30 degree, target coverage, HI, CI were improved, and the dose delivered to OAR was reduced compared with conventional supine position in brain radiation therapy. This work was supported by the Radiation Technology R&D program (No. 2013M2A2A7043498) and the Mid

  3. Five-Year Outcomes, Cosmesis, and Toxicity With 3-Dimensional Conformal External Beam Radiation Therapy to Deliver Accelerated Partial Breast Irradiation

    International Nuclear Information System (INIS)

    Rodríguez, Núria; Sanz, Xavier; Dengra, Josefa; Foro, Palmira; Membrive, Ismael; Reig, Anna; Quera, Jaume; Fernández-Velilla, Enric; Pera, Óscar; Lio, Jackson; Lozano, Joan; Algara, Manuel

    2013-01-01

    Purpose: To report the interim results from a study comparing the efficacy, toxicity, and cosmesis of breast-conserving treatment with accelerated partial breast irradiation (APBI) or whole breast irradiation (WBI) using 3-dimensional conformal external beam radiation therapy (3D-CRT). Methods and Materials: 102 patients with early-stage breast cancer who underwent breast-conserving surgery were randomized to receive either WBI (n=51) or APBI (n=51). In the WBI arm, 48 Gy was delivered to the whole breast in daily fractions of 2 Gy, with or without additional 10 Gy to the tumor bed. In the APBI arm, patients received 37.5 Gy in 3.75 Gy per fraction delivered twice daily. Toxicity results were scored according to the Radiation Therapy Oncology Group Common Toxicity Criteria. Skin elasticity was measured using a dedicated device (Multi-Skin-Test-Center MC-750-B2, CKelectronic-GmbH). Cosmetic results were assessed by the physician and the patients as good/excellent, regular, or poor. Results: The median follow-up time was 5 years. No local recurrences were observed. No significant differences in survival rates were found. APBI reduced acute side effects and radiation doses to healthy tissues compared with WBI (P 75% of patients in the APBI arm had excellent or good cosmesis, and these outcomes appear to be stable over time. The percentage of patients with excellent/good cosmetic results was similar in both groups. Conclusions: APBI delivered by 3D-CRT to the tumor bed for a selected group of early-stage breast cancer patients produces 5-year results similar to those achieved with conventional WBI

  4. The role of melatonin in radiation induced biochemical disturbances in brain and thyroid gland in adult male albino rats

    International Nuclear Information System (INIS)

    Abdel Kader, S.M.; EI-Sherbiny, E.M.

    2007-01-01

    Radiation induced changes in adult male albino male rats before and after melatonin administration were monitored to detect some biochemical changes in brain and thyroid gland. The parameters monitored were dopamine (DA), norepinephdne (NE) and gamma aminobutyric acid (GABA) in brain and triiodothyronine (T 3 ) thyroxine (T 4 ) and thyroid stimulating hormone (TSH) in serum of irradiated adult male albino rats before and after intraperitoneal injection of melatonin. Results indicated that 6.0 Gy whole body γ-irradiated rats showed gradual and significant decrease in DA, NE and GABA contents in different brain areas under investigation (cerebellum, pons+medulla oblongata, corpus striatum, cerebral cortex, hypothalamus, midbrain and hippocampus). The maximum effect of whole body γ-irradiation was observed after 21 days. Moreover, gradual and significant decrease in serum T 3 and T 4 levels were recorded after γ-irradiation. However, TSH level showed significant elevation throughout the experimental period. Melatonin at a dose level of 15 mg/kg b.wt. was intraperitoneally injected daily 30 minutes after 6.0 Gy whole body γ-irradiation, ameliorated DA, NE and GABA contents in different brain areas compared to those measured in irradiated rats. Moreover, melatonin gradually attenuated the effect of γ-irradiation on serum T 3 and T 4 levels to reach nearly the control level at day 21 after melatonin injection. However, melatonin ameliorated the elevated TSH level induced by γ-irradiation to reach its corresponding control value at day 21

  5. Neurosurgery and prognosis in patients with radiation-induced brain injury after nasopharyngeal carcinoma radiotherapy: a follow-up study

    International Nuclear Information System (INIS)

    Li, Yi; Shi, Xiaolei; Rong, Xiaoming; Peng, Ying; Tang, Yamei

    2013-01-01

    Radiotherapy is the standard radical treatment for nasopharyngeal carcinoma (NPC) and may cause radiation-induced brain injury (RI). Treatment for RI remains a challenge. We conducted this study to investigate the indications of neurosurgery, operation time and prognosis of patients with RI after NPC radiotherapy who underwent neurosurgical management. This was a follow-up study between January 2005 and July 2011. Fifteen NPC cases of RI who underwent neurosurgery were collected. Brain Magnetic resonance imaging (MRI), surgery and histology were studied. The outcome was assessed by LENT/SOMA scales and modified Rankin scale. Brain lesion resection (86.7%) was more common than decompressive craniotomy (13.3%). According to LENT/SOMA scale before and six months after surgery, 13 of 15, 12 of 15, 14 of 15, and 14 of 15 cases showed improvement at subjective, objective, management and analytic domains, respectively. 12 of 15 patients showed improvement of modified Rankin scale after surgery. Three patients who underwent emergency surgery showed significant improvement (average score increment of 2, 2.7, 2.7, 3 and 2 at LENT/SOMA scale subjective, objective, management, analytic, and modified Rankin scale, respectively), as compared with 12 cases underwent elective surgery (average score increment of 1, 1, 1.4, 1.8 and 1 at LENT SOMA scale subjective, objective, management, analytic, and modified Rankin scale, respectively). Neurosurgery, including brain necrotic tissue resection and decompressive craniotomy, improves the prognosis for RI patients, especially for those with indications of emergency surgery

  6. Organs at risk in the brain and their dose-constraints in adults and in children: A radiation oncologist’s guide for delineation in everyday practice

    International Nuclear Information System (INIS)

    Scoccianti, Silvia; Detti, Beatrice; Gadda, Davide; Greto, Daniela; Furfaro, Ilaria; Meacci, Fiammetta; Simontacchi, Gabriele; Di Brina, Lucia; Bonomo, Pierluigi; Giacomelli, Irene; Meattini, Icro; Mangoni, Monica; Cappelli, Sabrina; Cassani, Sara; Talamonti, Cinzia; Bordi, Lorenzo; Livi, Lorenzo

    2015-01-01

    Purpose: Accurate organs at risk definition is essential for radiation treatment of brain tumors. The aim of this study is to provide a stepwise and simplified contouring guide to delineate the OARs in the brain as it would be done in the everyday practice of planning radiotherapy for brain cancer treatment. Methods: Anatomical descriptions and neuroimaging atlases of the brain were studied. The dosimetric constraints used in literature were reviewed. Results: A Computed Tomography and Magnetic Resonance Imaging based detailed atlas was developed jointly by radiation oncologists, a neuroradiologist and a neurosurgeon. For each organ brief anatomical notion, main radiological reference points and useful considerations are provided. Recommended dose-constraints both for adult and pediatric patients were also provided. Conclusions: This report provides guidelines for OARs delineation and their dose-constraints for the treatment planning of patients with brain tumors

  7. [Interference of vitamin E on the brain tissue damage by electromagnetic radiation of cell phone in pregnant and fetal rats].

    Science.gov (United States)

    Gao, Xian; Luo, Rui; Ma, Bin; Wang, Hui; Liu, Tian; Zhang, Jing; Lian, Zhishun; Cui, Xi

    2013-07-01

    To investigate the interlerence ot vitamin E on brain tissue damage by electromagnetic radiation of cell phone in pregnant and fetal rats. 40 pregnant rats were randomly divided into five groups (positive control, negative control, low, middle and high dosage of vitamin E groups). The low, middle and high dosage of vitamin E groups were supplemented with 5, 15 and 30 mg/ml vitamin E respectively since the first day of pregnancy. And the negative control group and the positive control group were given peanut oil without vitamin E. All groups except for the negative control group were exposed to 900MHz intensity of cell phone radiation for one hour each time, three times per day for 21 days. After accouchement, the right hippocampus tissue of fetal rats in each group was taken and observed under electron microscope. The vitality of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the content of malondialdehyde (MDA) in pregnant and fetal rats' brain tissue were tested. Compared with the negative control group, the chondriosomes in neuron and neuroglia of brain tissues was swelling, mild edema was found around the capillary, chromatin was concentrated and collected, and bubbles were formed in vascular endothelial cells (VEC) in the positive fetal rat control group, whereas the above phenomenon was un-conspicuous in the middle and high dosage of vitamin E groups. We can see uniform chromatin, abundant mitochondrion, rough endoplasmic reticulum and free ribosomes in the high dosage group. The apoptosis has not fond in all groups'sections. In the antioxidase activity analysis, compared with the negative control group, the vitality of SOD and GSH-Px significantly decreased and the content of MDA significantly increased both in the pregnant and fetal rats positive control group (P electromagnetic radiation of cell phone in pregnant rats and fetal rats.

  8. Treatment planning and 3D dose verification of whole brain radiation therapy with hippocampal avoidance in rats

    International Nuclear Information System (INIS)

    Yoon, S W; Miles, D; Reinsvold, M; Kirsch, D; Oldham, M; Cramer, C

    2017-01-01

    Despite increasing use of stereotactic radiosurgery, whole brain radiotherapy (WBRT) continues to have a therapeutic role in a selected subset of patients. Selectively avoiding the hippocampus during such treatment (HA-WBRT) emerged as a strategy to reduce the cognitive morbidity associated with WBRT and gave rise to a recently published the phase II trial (RTOG 0933) and now multiple ongoing clinical trials. While conceptually hippocampal avoidance is supported by pre-clinical evidence showing that the hippocampus plays a vital role in memory, there is minimal pre-clinic data showing that selectively avoiding the hippocampus will reduce radiation-induced cognitive decline. Largely the lack of pre-clinical evidence can be attributed to the technical hurdles associated with delivering precise conformal treatment the rat brain. In this work we develop a novel conformal HA-WBRT technique for Wistar rats, utilizing a 225kVp micro-irradiator with precise 3D-printed radiation blocks designed to spare hippocampus while delivering whole brain dose. The technique was verified on rodent-morphic Presage ® 3D dosimeters created from micro-CT scans of Wistar rats with Duke Large Field-of-View Optical Scanner (DLOS) at 1mm isotropic voxel resolution. A 4-field box with parallel opposed AP-PA and two lateral opposed fields was explored with conformal hippocampal sparing aided by 3D-printed radiation blocks. The measured DVH aligned reasonably well with that calculated from SmART Plan Monte Carlo simulations with simulated blocks for 4-field HA-WBRT with both demonstrating hippocampal sparing of 20% volume receiving less than 30% the prescription dose. (paper)

  9. Effect of 60Co γ radiation on the valyl-tRNA synthetase isolated from chick embryo brain

    International Nuclear Information System (INIS)

    Boloni, E.; Szabo, L.D.

    1978-01-01

    he effect of 60 Coγ irradiation on the activity of valyl-tRNA synthetase isolated from chick embryo brain was studied. The enzyme activity exponentially decreased in the dose range 10 to 200 krad. The first step of the enzyme action, i.e. amino acid activation, was found to be less sensitive to irradiation than the whole reaction, the formation of valyl-tRNA. 2-Mercapto ethanol and/or glycerol had a significant radioprotective effect. The lesion caused by radiation in the enzyme was also influenced by its concentration during exposure (diluted effect). According to gel-electrophoretic experiments, no chain rupture occurred in the enzyme molecule. Not even a change in Ksub(m) was observed; however, the maximum velocity of the reaction was found to decrease with increasing radiation dose. (author)

  10. Histopathological investigation of radiation necrosis. Coagulation necrosis in the irradiated and non-irradiated brain tumors and in the normal brain tissue

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, N [Niigata Univ. (Japan). Brain Research Inst.

    1977-01-01

    Eighty four irradiated tumors (including 59 gliomas) and the surrounding brain tissue were analyzed. In 'normal' brain tissue, typical coagulation necrosis attributable to irradiation was observed in the cerebral white matter, presenting a whitish-yellow color but no remarkable changes in volume. Histologically there was complete desintegration of myelin and axon. Vascular changes included hyalinous thickening, concentric cleavage, fibrinoid degeneration, adventitial fibrosis and edema of small arteries, fibrin thrombi or occlusion of arterioles and capillaries, and telangiectasia of small veins and venules. While other tumors showed hyalinous or fibrous scar tissue and decrease in volume, the gliomas maintained their original volume without residual tumor cells. Massive coagulation necrosis was occasionally found even in full volume, non-irradiated gliomas (controls), although the changes were fewer and not so varied as in typical radiation necrosis. With small dosages, it was difficult to judge whether the necrosis was caused by irradiation or occurred spontaneously. Coagulation necrosis in tumor tissue was found in 25 of 59 cases (42%) of irradiated gliomas, but in only 2 of 49 cases (4%) of the nonirradiated gliomas. In 49 cases no coagulation necrosis of the surrounding tissue was found. Although histopathological judgement is difficult, it is suggested that there is a significant correlation between coagulation necrosis and irradiation. Discussion of the relationship between coagulation necrosis and NSD (nominal standard dose) led to the conclusion that coagulation necrosis will not be caused by irradiation of less than 1400 rets in NSD.

  11. Sparing of the hippocampus and limbic circuit during whole brain radiation therapy: a dosimetric study using helical tomotherapy

    International Nuclear Information System (INIS)

    Marsh, J.C.; Gielda, B.T.; Herskovic, A.M.; Turian, J.V.

    2010-01-01

    Full text: The study aims to assess the feasibility of dosimetrically sparing the limbic circuit during whole brain radiation therapy (WBRT) and prophylactic cranial irradiation (PCI). Methods and Materials: We contoured the brain/brainstem on fused MRI and CT as the target volume (PTV) in 11 patients, excluding the hippocampus and the rest of the limbic circuit, which were considered organs at risk (OARs). PCI and WBRT helical tomotherapy plans were prepared for each patient with a 1.0-cm field width, pitch 0.285, initial modulation factor = 2.5. We attempted to spare the hippocampus and the rest of the limbic circuit while treating the rest of the brain to 30 Gy in 15 fractions (PCI) or 35 Gy in 14 fractions (WBRT) with VlOO ∼ 95%. The quality of the plans was assessed by calculating mean dose and equivalent uniform dose (EUD) for OARs and the % volume of the PTV receiving the prescribed dose, V 100. Results: In the PCI plans, mean doses/EUD were: hippocampus 12.5 Gy/ 14.23 Gy, rest of limbic circuit 17.0 Gy/19.02 Gy. In the WBRT plans, mean doses/EUD were: hippocampus 14.3 Gy/16.07 Gy, rest of limbic circuit 17.9 Gy/20.74 Gy. The mean VlOO for the rest of the brain (PTV) were 94.7% (PCl) and 95.1 % (WBRT). Mean PCI and WBRT treatment times were essentially identical (mean 15.23 min, range 14.27-17.5). Conclusions: It is dosimetrically feasible to spare the hippocampus and the rest of the limbic circuit using helical tomotherapy while treating the rest of the brain to full dose.

  12. Calmodulin-activated cyclic nucleotide phosphodiesterase from brain. Relationship of subunit structure to activity assessed by radiation inactivation

    International Nuclear Information System (INIS)

    Kincaid, R.L.; Kemdner, E.; Manganiello, V.C.; Osborne, J.C.; Vaughan, M.

    1981-01-01

    The apparent target sizes of the basal and calmodulin-dependent activities of calmodulin-activated phosphodiesterase from bovine brain were estimated using target theory analysis of data from radiation inactivation experiments. Whether crude or highly purified samples were irradiated, the following results were obtained. Low doses of radiation caused a 10 to 15% increase in basal activity, which, with further irradiation, decayed with an apparent target size of approx.60,000 daltons. Calmodulin-dependent activity decayed with an apparent target size of approx.105,000 daltons. The percentage stimulation of enzyme activity by calmodulin decreased markedly as a function of radiation dosage. These observations are consistent with results predicted by computer-assisted modeling based on the assumptions that: 1) the calmodulin-activated phosphodiesterase exists as a mixture of monomers which are fully active in the absence of calmodulin and dimers which are inactive in the absence of calmodulin; 2) in the presence of calmodulin, a dimer exhibits activity equal to that of two monomers; 3) on radiation destruction of a dimer, an active monomer is generated. This monomer-dimer hypothesis provides a plausible explanation for and definition of basal and calmodulin-dependent phosphodiesterase activity

  13. Can We Predict Plan Quality for External Beam Partial Breast Irradiation: Results of a Multicenter Feasibility Study (Trans Tasman Radiation Oncology Group Study 06.02)

    Energy Technology Data Exchange (ETDEWEB)

    Kron, Tomas, E-mail: Tomas.Kron@petermac.org [Peter MacCallum Cancer Centre, Departments of Radiation Oncology, Physical Sciences and Radiation Therapy, Melbourne, Victoria (Australia); Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria (Australia); School of Science, Engineering and Technology, Royal Melbourne Institute of Technology University, Melbourne, Victoria (Australia); Willis, David; Link, Emma [Peter MacCallum Cancer Centre, Departments of Radiation Oncology, Physical Sciences and Radiation Therapy, Melbourne, Victoria (Australia); Lehman, Margot [Princess Alexandra Hospital, Department of Radiation Oncology, Brisbane, Queensland (Australia); Campbell, Gillian [Auckland City Hospital, Department of Radiation Oncology, Auckland (New Zealand); O' Brien, Peter [Newcastle Calvary Mater Hospital, Department of Radiation Oncology, Newcastle, NSW (Australia); Chua, Boon [Peter MacCallum Cancer Centre, Departments of Radiation Oncology, Physical Sciences and Radiation Therapy, Melbourne, Victoria (Australia); Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria (Australia)

    2013-11-15

    Purpose: Partial breast irradiation (PBI) after lumpectomy may be an option for selected patients with early breast cancer. A feasibility study of accelerated PBI delivered using external beam 3-dimensional conformal radiation therapy (RT) was undertaken at 8 Australasian centers. The present study evaluated the impact of patient, tumor, and RT technique-related factors on the quality of RT plans as determined by the dose–volume parameters of organs at risk. Methods and Materials: Forty-eight patients were enrolled in the study. All RT plans were centrally reviewed using predefined dosimetric criteria before commencement and after completion of protocol therapy. The RT plans of 47 patients met the dose–volume constraints, and all 47 patients received PBI to a prescribed dose of 38.5 Gy in 10 fractions. The RT plan quality was determined by volumes of the ipsilateral whole breast, lung, and heart that received 50% and 95%; 30%; and 5% of the prescribed dose, respectively. Patient, tumor, and RT technique-related factors were investigated for association with the parameters of RT plan quality. Results: The ratio of the planning target volume to the ipsilateral whole-breast volume was significantly associated with the ipsilateral breast doses on multiple variable analyses. The distance of the postlumpectomy surgical cavity from the heart and lung were predictive for heart and lung doses, respectively. A distance between surgical cavity and heart of >4 cm typically resulted in <1% of the heart volume receiving 5 Gy or less. It was more difficult to meet the heart dose constraint for left-sided and medially located tumors. Conclusions: Partial breast irradiation using 3-dimensional conformal RT was feasible within the study constraints. The ratio of planning target volume to ipsilateral whole-breast volume and the distance of surgical cavity from the heart were significant predictors of the quality of treatment plan for external beam PBI.

  14. Can We Predict Plan Quality for External Beam Partial Breast Irradiation: Results of a Multicenter Feasibility Study (Trans Tasman Radiation Oncology Group Study 06.02)

    International Nuclear Information System (INIS)

    Kron, Tomas; Willis, David; Link, Emma; Lehman, Margot; Campbell, Gillian; O'Brien, Peter; Chua, Boon

    2013-01-01

    Purpose: Partial breast irradiation (PBI) after lumpectomy may be an option for selected patients with early breast cancer. A feasibility study of accelerated PBI delivered using external beam 3-dimensional conformal radiation therapy (RT) was undertaken at 8 Australasian centers. The present study evaluated the impact of patient, tumor, and RT technique-related factors on the quality of RT plans as determined by the dose–volume parameters of organs at risk. Methods and Materials: Forty-eight patients were enrolled in the study. All RT plans were centrally reviewed using predefined dosimetric criteria before commencement and after completion of protocol therapy. The RT plans of 47 patients met the dose–volume constraints, and all 47 patients received PBI to a prescribed dose of 38.5 Gy in 10 fractions. The RT plan quality was determined by volumes of the ipsilateral whole breast, lung, and heart that received 50% and 95%; 30%; and 5% of the prescribed dose, respectively. Patient, tumor, and RT technique-related factors were investigated for association with the parameters of RT plan quality. Results: The ratio of the planning target volume to the ipsilateral whole-breast volume was significantly asso