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Sample records for red marrow dosimetry

  1. Investigation of effect of variations in bone fraction and red marrow cellularity on bone marrow dosimetry in radio-immunotherapy

    NASA Astrophysics Data System (ADS)

    Wilderman, S. J.; Roberson, P. L.; Bolch, W. E.; Dewaraja, Y. K.

    2013-07-01

    A method is described for computing patient-specific absorbed dose rates to active marrow which accounts for spatial variation in bone volume fraction and marrow cellularity. A module has been added to the 3D Monte Carlo dosimetry program DPM to treat energy deposition in the components of bone spongiosa distinctly. Homogeneous voxels in regions containing bone spongiosa (as defined on CT images) are assumed to be comprised only of bone, active (red) marrow and inactive (yellow) marrow. Cellularities are determined from biopsy, and bone volume fractions are computed from cellularities and CT-derived voxel densities. Electrons are assumed to deposit energy locally in the three constituent components in proportions determined by electron energy absorption fractions which depend on energy, cellularity, and bone volume fraction, and which are either taken from the literature or are derived from Monte Carlo simulations using EGS5. Separate algorithms are used to model primary β particles and secondary electrons generated after photon interactions. Treating energy deposition distinctly in bone spongiosa constituents leads to marrow dosimetry results which differ from homogeneous spongiosa dosimetry by up to 20%. Dose rates in active marrow regions with cellularities of 20, 50, and 80% can vary by up to 20%, and can differ by up to 10% as a function of bone volume fraction. Dose to bone marrow exhibits a strong dependence on marrow cellularity and a potentially significant dependence on bone volume fraction.

  2. Investigation of effect of variations in bone fraction and red marrow cellularity on bone marrow dosimetry in radio-immunotherapy.

    PubMed

    Wilderman, S J; Roberson, P L; Bolch, W E; Dewaraja, Y K

    2013-07-21

    A method is described for computing patient-specific absorbed dose rates to active marrow which accounts for spatial variation in bone volume fraction and marrow cellularity. A module has been added to the 3D Monte Carlo dosimetry program DPM to treat energy deposition in the components of bone spongiosa distinctly. Homogeneous voxels in regions containing bone spongiosa (as defined on CT images) are assumed to be comprised only of bone, active (red) marrow and inactive (yellow) marrow. Cellularities are determined from biopsy, and bone volume fractions are computed from cellularities and CT-derived voxel densities. Electrons are assumed to deposit energy locally in the three constituent components in proportions determined by electron energy absorption fractions which depend on energy, cellularity, and bone volume fraction, and which are either taken from the literature or are derived from Monte Carlo simulations using EGS5. Separate algorithms are used to model primary β particles and secondary electrons generated after photon interactions. Treating energy deposition distinctly in bone spongiosa constituents leads to marrow dosimetry results which differ from homogeneous spongiosa dosimetry by up to 20%. Dose rates in active marrow regions with cellularities of 20, 50, and 80% can vary by up to 20%, and can differ by up to 10% as a function of bone volume fraction. Dose to bone marrow exhibits a strong dependence on marrow cellularity and a potentially significant dependence on bone volume fraction.

  3. Establishing a clinically meaningful predictive model of hematologic toxicity in nonmyeloablative targeted radiotherapy: practical aspects and limitations of red marrow dosimetry.

    PubMed

    Siegel, Jeffry A

    2005-04-01

    In either heavily pretreated or previously untreated patient populations, dosimetry holds the promise of playing an integral role in the physician's ability to adjust therapeutic activity prescriptions to limit excessive hematologic toxicity in individual patients. However, red marrow absorbed doses have not been highly predictive of hematopoietic toxicity. Although the accuracy of red marrow dose estimates is expected to improve as more patient-specific models are implemented, these model-calculated absorbed doses more than likely will have to be adjusted by parameters that adequately characterize bone marrow tolerance in the heavily pretreated patients most likely to receive nonmyeloablative radiolabeled antibody therapy. Models need to be established that consider not only absorbed dose but also parameters that are indicative of pretherapy bone marrow reserve and radiosensitivity so that a clinically meaningful predictive model of hematologic toxicity can be established.

  4. Red marrow and blood dosimetry in 131I treatment of metastatic thyroid carcinoma: pre-treatment versus in-therapy results

    NASA Astrophysics Data System (ADS)

    Giostra, A.; Richetta, E.; Pasquino, M.; Miranti, A.; Cutaia, C.; Brusasco, G.; Pellerito, R. E.; Stasi, M.

    2016-06-01

    Treatment with radioiodine is a standard procedure for patients with well-differentiated thyroid cancer, but the main approach to the therapy is still empiric, consisting of the administration of fixed activities. A predictive individualized dosimetric study may represent an important tool for physicians to determine the best activity to prescribe. The aim of this work is to compare red marrow and blood absorbed dose values obtained in the pre-treatment (PT) dosimetry phase with those obtained in the in-treatment (IT) dosimetry phase in order to estimate the predictive power of PT trial doses and to determine if they can be used as a decision-making tool to safely administer higher 131I activity to potentially increase the efficacy of treatment. The PT and IT dosimetry for 50 patients has been evaluated using three different dosimetric approaches. In all three approaches blood and red marrow doses, are calculated as the sum of two components, the dose from 131I activity in the blood and the dose from 131I activity located in the remainder of the body (i.e. the blood and whole-body contributions to the total dose). PT and IT dose values to blood and red marrow appear to be well correlated irrespective of the dosimetric approach used. Linear regression analyses of PT and IT total doses, for blood and red marrow, and the whole-body contribution to these doses, showed consistent best fit slope and correlation coefficient values of approximately 0.9 and 0.6, respectively: analyses of the blood dose contribution to the total doses also yielded similar values for the best fit slope but with correlation coefficient values of approximately 0.4 reflecting the greater variance in these dose estimates. These findings suggest that pre-treatment red marrow dose assessments may represent an important tool to personalize metastatic thyroid cancer treatment, removing the constraints of a fixed activity approach and permitting potentially more effective higher 131I activities to be

  5. Red marrow and blood dosimetry in (131)I treatment of metastatic thyroid carcinoma: pre-treatment versus in-therapy results.

    PubMed

    Giostra, A; Richetta, E; Pasquino, M; Miranti, A; Cutaia, C; Brusasco, G; Pellerito, R E; Stasi, M

    2016-06-07

    Treatment with radioiodine is a standard procedure for patients with well-differentiated thyroid cancer, but the main approach to the therapy is still empiric, consisting of the administration of fixed activities. A predictive individualized dosimetric study may represent an important tool for physicians to determine the best activity to prescribe. The aim of this work is to compare red marrow and blood absorbed dose values obtained in the pre-treatment (PT) dosimetry phase with those obtained in the in-treatment (IT) dosimetry phase in order to estimate the predictive power of PT trial doses and to determine if they can be used as a decision-making tool to safely administer higher (131)I activity to potentially increase the efficacy of treatment. The PT and IT dosimetry for 50 patients has been evaluated using three different dosimetric approaches. In all three approaches blood and red marrow doses, are calculated as the sum of two components, the dose from (131)I activity in the blood and the dose from (131)I activity located in the remainder of the body (i.e. the blood and whole-body contributions to the total dose). PT and IT dose values to blood and red marrow appear to be well correlated irrespective of the dosimetric approach used. Linear regression analyses of PT and IT total doses, for blood and red marrow, and the whole-body contribution to these doses, showed consistent best fit slope and correlation coefficient values of approximately 0.9 and 0.6, respectively: analyses of the blood dose contribution to the total doses also yielded similar values for the best fit slope but with correlation coefficient values of approximately 0.4 reflecting the greater variance in these dose estimates. These findings suggest that pre-treatment red marrow dose assessments may represent an important tool to personalize metastatic thyroid cancer treatment, removing the constraints of a fixed activity approach and permitting potentially more effective higher (131)I

  6. Evaluation of dual energy quantitative CT for determining the spatial distributions of red marrow and bone for dosimetry in internal emitter radiation therapy

    SciTech Connect

    Goodsitt, Mitchell M. Shenoy, Apeksha; Howard, David; Christodoulou, Emmanuel; Dewaraja, Yuni K.; Shen, Jincheng; Schipper, Matthew J.; Wilderman, Scott; Chun, Se Young

    2014-05-15

    Purpose: To evaluate a three-equation three-unknown dual-energy quantitative CT (DEQCT) technique for determining region specific variations in bone spongiosa composition for improved red marrow dose estimation in radionuclide therapy. Methods: The DEQCT method was applied to 80/140 kVp images of patient-simulating lumbar sectional body phantoms of three sizes (small, medium, and large). External calibration rods of bone, red marrow, and fat-simulating materials were placed beneath the body phantoms. Similar internal calibration inserts were placed at vertebral locations within the body phantoms. Six test inserts of known volume fractions of bone, fat, and red marrow were also scanned. External-to-internal calibration correction factors were derived. The effects of body phantom size, radiation dose, spongiosa region segmentation granularity [single (∼17 × 17 mm) region of interest (ROI), 2 × 2, and 3 × 3 segmentation of that single ROI], and calibration method on the accuracy of the calculated volume fractions of red marrow (cellularity) and trabecular bone were evaluated. Results: For standard low dose DEQCT x-ray technique factors and the internal calibration method, the RMS errors of the estimated volume fractions of red marrow of the test inserts were 1.2–1.3 times greater in the medium body than in the small body phantom and 1.3–1.5 times greater in the large body than in the small body phantom. RMS errors of the calculated volume fractions of red marrow within 2 × 2 segmented subregions of the ROIs were 1.6–1.9 times greater than for no segmentation, and RMS errors for 3 × 3 segmented subregions were 2.3–2.7 times greater than those for no segmentation. Increasing the dose by a factor of 2 reduced the RMS errors of all constituent volume fractions by an average factor of 1.40 ± 0.29 for all segmentation schemes and body phantom sizes; increasing the dose by a factor of 4 reduced those RMS errors by an average factor of 1.71 ± 0.25. Results

  7. Methods for the inclusion of shallow marrow and adipose tissue in pathlength-based skeletal dosimetry

    NASA Astrophysics Data System (ADS)

    Jokisch, D. W.; Rajon, D. A.; Patton, P. W.; Bolch, W. E.

    2011-05-01

    Distributions of linear pathlength measurements have been utilized in skeletal dosimetry of internally emitted short-range particles for over 30 years. This work reviews the methods for coupling these distributions to range-energy data. A revised methodology is presented for handling the insertion of the additional dosimetric target region (shallow marrow) and medium (adipose tissue) into the dosimetry algorithm. The methodology is shown to reduce the volume fraction of shallow marrow in the trabecular skeleton over existing methodologies. Finally, theoretical low and high-energy checkpoints are derived for use in checking the absorbed fraction and specific absorbed fraction results for a variety of source and target combinations.

  8. Bone marrow dosimetry via microCT imaging and stem cell spatial mapping

    NASA Astrophysics Data System (ADS)

    Kielar, Kayla N.

    In order to make predictions of radiation dose in patients undergoing targeted radionuclide therapy of cancer, an accurate model of skeletal tissues is necessary. Concerning these tissues, the dose-limiting factor in these therapies is the toxicity of the hematopoietically active bone marrow. In addition to acute effects, one must be concerned as well with long-term stochastic effects such as radiation-induced leukemia. Particular cells of interest for both toxicity and cancer risk are the hematopoietic stem cells (HSC), found within the active marrow regions of the skeleton. At present, cellular-level dosimetry models are complex, and thus we cannot model individual stem cells in an anatomic model of the patient. As a result, one reverts to looking at larger tissue regions where these cell populations may reside. To provide a more accurate marrow dose assessment, the skeletal dosimetry model must also be patient-specific. That is, it should be designed to match as closely as possible to the patient undergoing treatment. Absorbed dose estimates then can be tailored based on the skeletal size and trabecular microstructure of an individual for an accurate prediction of marrow toxicity. Thus, not only is it important to accurately model the target tissues of interest in a normal patient, it is important to do so for differing levels of marrow health. A skeletal dosimetry model for the adult female was provided for better predictions of marrow toxicity in patients undergoing radionuclide therapy. This work is the first fully established gender specific model for these applications, and supersedes previous models in scalability of the skeleton and radiation transport methods. Furthermore, the applicability of using bone marrow biopsies was deemed sufficient in prediction of bone marrow health, specifically for the hematopoietic stem cell population. The location and concentration of the HSC in bone marrow was found to follow a spatial gradient from the bone trabeculae

  9. Aspects of the dosimetry of radionuclides within the skeleton with particular emphasis on the active marrow

    SciTech Connect

    Eckerman, K.F.

    1985-01-01

    Epidemiological surveys on man and results from animal experiments have shown that two tissues associated with the skeleton are of primary concern with respect to cancer induction by ionizing radiation. These are the cells on or near endosteal surfaces of bone, from which osteosarcomas are thought to arise, and hematopoietic bone marrow, which is associated with leukemia. The complex geometry of the soft tissue-bone intermixture makes calculations of absorbed dose to these target regions a difficult problem. In the case of photon or neutron radiations, charged particle equilibrium may not exist in the vicinity of soft tissue-bone mineral interface. In this paper a general study of the dosimetry of radionuclides within the skeleton is presented. Dosimetric data consistent with the MIRD schema and reflecting the physical and anatomical parameters defining the energy deposition are tabulated for the relevant target regions. 27 refs., 5 figs., 5 tabs.

  10. SU-E-T-600: In Vivo Dosimetry for Total Body and Total Marrow Irradiations with Optically Stimulated Luminescence Dosimeters

    SciTech Connect

    Niedbala, M; Save, C; Cygler, J

    2014-06-01

    Purpose: To evaluate the feasibility of using optically stimulated luminescence dosimeters (OSLDs) for in-vivo dosimetry of patients undergoing Total Body and Total Marrow Irradiations (TBI and TMI). Methods: TBI treatments of 12 Gy were delivered in 6 BID fractions with the patient on a moving couch under a static 10 MV beam (Synergy, Elekta). TMI treatments of 18 Gy in 9 BID fractions were planned and delivered using a 6 MV TomoTherapy unit (Accuray). To provide a uniform dose to the entire patient length, the treatment was split into 2 adjacent fields junctioned in the thigh region. Our standard clinical practice involves in vivo dosimetry with MOSFETs for each TBI fraction and TLDs for at least one fraction of the TMI treatment for dose verification. In this study we also used OSLDs. Individual calibration coefficients were obtained for the OSLDs based on irradiations in a solid water phantom to the dose of 50 cGy from Elekta Synergy 10 MV (TBI) and 6 MV (TMI) beams. Calibration coefficients were calculated based on the OSLDs readings taken 2 hrs post-irradiation. For in vivo dosimetry OSLDs were placed alongside MOSFETs for TBI patients and in approximately the same locations as the TLDs for TMI patients. OSLDs were read 2 hours post treatment and compared to the MOSFET and TLD results. Results: OSLD measured doses agreed within 5% with MOSFET and TLD results, with the exception of the junction region in the TMI patient due to very high dose gradient and difficulty of precise and reproducible detector placement. Conclusion: OSLDs are useful for in vivo dosimetry of TBI and TMI patients. The quick post-treatment readout is an advantage over TLDs, allowing the results to be obtained between BID fractions, while wireless detectors are advantageous over MOSFETs for treatments involving a moving couch.

  11. Pure red-cell aplasia of long duration after major ABO-incompatible bone marrow transplantation.

    PubMed

    Volin, L; Ruutu, T

    1990-01-01

    We describe a patient with an exceptionally long-lasting red-cell aplasia of 330 days following ABO-incompatible bone marrow transplantation (BMT). Before BMT, the anti-B titre was high, 1:1,024, and it was only temporarily reduced by extensive plasma exchange. The anti-B titre remained above the level of 1:64 for 270 days, and host-derived isoagglutinin could still be detected 3 years after BMT. In vitro bone marrow cultures during the red-cell aplasia showed greatly reduced numbers or total absence of CFU-E, while the number of BFU-E colonies was only moderately subnormal. Six years after BMT, bone marrow and peripheral-blood cell counts are normal.

  12. Hyperemic peripheral red marrow in a patient with sickle cell anemia demonstrated on Tc-99m labeled red blood cell venography

    SciTech Connect

    Heiden, R.A.; Locko, R.C.; Stent, T.R. )

    1991-03-01

    A 25-year-old gravid woman, homozygous for sickle cell anemia, with a history of recent deep venous thrombosis, was examined using Tc-99m labeled red blood cell venography for recurrent thrombosis. Although negative for thrombus, the study presented an unusual incidental finding: the patient's peripheral bone marrow was hyperemic in a distribution consistent with peripheral red bone marrow expansion. Such a pattern has not been documented before using this technique. This report supports other literature that has demonstrated hyperemia of peripheral red bone marrow in other hemolytic anemias. This finding may ultimately define an additional role of scintigraphy in assessing the pathophysiologic status of the sickle cell patient.

  13. A simple technique for red blood cell removal in major ABO-incompatible bone marrow transplantation.

    PubMed

    Mayer, G; Wernet, D; Northoff, H; Schneider, W

    1994-01-01

    A simple technique for red blood cell (RBC) removal in major ABO-incompatible bone marrow transplantation is reported requiring two centrifugation steps, special blood bags and a mechanical device to separate the buffy coat from RBCs within the bag. In 42 transplantations an average of 84% of nucleated cells was recovered with an average contamination of 7.5 ml packed RBCs. The preparations were well tolerated in all patients whose isoagglutinin titers had not been reduced. Bone marrow engraftment was not significantly different from control groups.

  14. Comparison of mathematical models for red marrow and blood absorbed dose estimation in the radioiodine treatment of advanced differentiated thyroid carcinoma

    NASA Astrophysics Data System (ADS)

    Miranti, A.; Giostra, A.; Richetta, E.; Gino, E.; Pellerito, R. E.; Stasi, M.

    2015-02-01

    Metastatic and recurrent differentiated thyroid carcinoma is preferably treated with 131I, whose administered activity is limited by red marrow (RM) toxicity, originally correlated by Benua to a blood absorbed dose higher than 2 Gy. Afterward a variety of dosimetric approaches has been proposed. The aim of this work is to compare the results of the Benua formula with the ones of other three blood and RM absorbed dose formulae. Materials and methods have been borrowed by the dosimetric protocol of the Italian Internal Dosimetry group and adapted to the routine of our centre. Wilcoxon t-tests and percentage differences have been applied for comparison purposes. Results are significantly different (p < 0.05) from each other, with an average percentage difference between Benua versus other results of -22%. The dosimetric formula applied to determine blood or RM absorbed dose may contribute significantly to increase heterogeneity in absorbed dose and dose-response results. Standardization should be a major objective.

  15. Normalization of red cell enolase level following allogeneic bone marrow transplantation in a child with Diamond-Blackfan anemia.

    PubMed

    Park, Jeong A; Lim, Yeon Jung; Park, Hyeon Jin; Kong, Sun Young; Park, Byung Kiu; Ghim, Thad T

    2010-04-01

    We describe a girl with Diamond-Blackfan anemia with accompanying red cell enolase deficiency. At the age of 9 yr old, the patient received allogeneic bone marrow transplantation from her HLA-identical sister who had normal red cell enolase activity. While the post transplant DNA analysis with short tandem repeat has continuously demonstrated a stable mixed chimerism on follow-up, the patient remains transfusion independent and continues to show a steady increase in red cell enolase activity for over two and a half years following bone marrow transplantation.

  16. 660 nm red light-enhanced bone marrow mesenchymal stem cell transplantation for hypoxic-ischemic brain damage treatment.

    PubMed

    Li, Xianchao; Hou, Wensheng; Wu, Xiaoying; Jiang, Wei; Chen, Haiyan; Xiao, Nong; Zhou, Ping

    2014-02-01

    Bone marrow mesenchymal stem cell transplantation is an effective treatment for neonatal hypoxic-ischemic brain damage. However, the in vivo transplantation effects are poor and their survival, colonization and differentiation efficiencies are relatively low. Red or near-infrared light from 600-1,000 nm promotes cellular migration and prevents apoptosis. Thus, we hypothesized that the combination of red light with bone marrow mesenchymal stem cell transplantation would be effective for the treatment of hypoxic-ischemic brain damage. In this study, the migration and colonization of cultured bone marrow mesenchymal stem cells on primary neurons after oxygen-glucose deprivation were detected using Transwell assay. The results showed that, after a 40-hour irradiation under red light-emitting diodes at 660 nm and 60 mW/cm(2), an increasing number of green fluorescence-labeled bone marrow mesenchymal stem cells migrated towards hypoxic-ischemic damaged primary neurons. Meanwhile, neonatal rats with hypoxic-ischemic brain damage were given an intraperitoneal injection of 1 × 10(6) bone marrow mesenchymal stem cells, followed by irradiation under red light-emitting diodes at 660 nm and 60 mW/cm(2) for 7 successive days. Shuttle box test results showed that, after phototherapy and bone marrow mesenchymal stem cell transplantation, the active avoidance response rate of hypoxic-ischemic brain damage rats was significantly increased, which was higher than that after bone marrow mesenchymal stem cell transplantation alone. Experimental findings indicate that 660 nm red light emitting diode irradiation promotes the migration of bone marrow mesenchymal stem cells, thereby enhancing the contribution of cell transplantation in the treatment of hypoxic-ischemic brain damage.

  17. Successful treatment of refractory acquired pure red cell aplasia (PRCA) by allogeneic bone marrow transplantation.

    PubMed

    Müller, B U; Tichelli, A; Passweg, J R; Nissen, C; Wodnar-Filipowicz, A; Gratwohl, A

    1999-06-01

    This case describes a 16-year-old woman treated successfully by a bone marrow transplant from her HLA-identical brother for refractory acquired pure red cell aplasia. Conditioning was as for severe aplastic anaemia with cyclophosphamide 4 x 50 mg/kg and antithymocyte globulin. Complete donor type engraftment at 3 months reversed to full autologous reconstitution at 2 years with normal haemopoiesis. The potential implications on pathogenesis of the disease as well as on treatment of autoimmune disorders by stem cell transplantation are discussed.

  18. Use of Monte Carlo simulations with a realistic rat phantom for examining the correlation between hematopoietic system response and red marrow absorbed dose in Brown Norway rats undergoing radionuclide therapy with {sup 177}Lu- and {sup 90}Y-BR96 mAbs

    SciTech Connect

    Larsson, Erik; Ljungberg, Michael; Martensson, Linda; Nilsson, Rune; Tennvall, Jan; Strand, Sven-Erik; Joensson, Bo-Anders

    2012-07-15

    Purpose: Biokinetic and dosimetry studies in laboratory animals often precede clinical radionuclide therapies in humans. A reliable evaluation of therapeutic efficacy is essential and should be based on accurate dosimetry data from a realistic dosimetry model. The aim of this study was to develop an anatomically realistic dosimetry model for Brown Norway rats to calculate S factors for use in evaluating correlations between absorbed dose and biological effects in a preclinical therapy study. Methods: A realistic rat phantom (Roby) was used, which has some flexibility that allows for a redefinition of organ sizes. The phantom was modified to represent the anatomic geometry of a Brown Norway rat, which was used for Monte Carlo calculations of S factors. Kinetic data for radiolabeled BR96 monoclonal antibodies were used to calculate the absorbed dose. Biological data were gathered from an activity escalation study with {sup 90}Y- and {sup 177}Lu-labeled BR96 monoclonal antibodies, in which blood cell counts and bodyweight were examined up to 2 months follow-up after injection. Reductions in white blood cell and platelet counts and declines in bodyweight were quantified by four methods and compared to the calculated absorbed dose to the bone marrow or the total body. Results: A red marrow absorbed dose-dependent effect on hematological parameters was observed, which could be evaluated by a decrease in blood cell counts. The absorbed dose to the bone marrow, corresponding to the maximal tolerable activity that could safely be administered, was determined to 8.3 Gy for {sup 177}Lu and 12.5 Gy for {sup 90}Y. Conclusions: There was a clear correlation between the hematological effects, quantified with some of the studied parameters, and the calculated red marrow absorbed doses. The decline in body weight was stronger correlated to the total body absorbed dose, rather than the red marrow absorbed dose. Finally, when considering a constant activity concentration, the phantom

  19. Resolution enhancement in MR spectroscopy of red bone marrow fat via intermolecular double-quantum coherences

    NASA Astrophysics Data System (ADS)

    Bao, Jianfeng; Cui, Xiaohong; Huang, Yuqing; Zhong, Jianhui; Chen, Zhong

    2015-08-01

    High-resolution 1H magnetic resonance spectroscopy (MRS) is generally inaccessible in red bone marrow (RBM) tissues using conventional MRS techniques. This is because signal from these tissues suffers from severe inhomogeneity in the main static B0 field originated from the intrinsic honeycomb structures in trabecular bone. One way to reduce effects of B0 field inhomogeneity is by using the intermolecular double quantum coherence (iDQC) technique, which has been shown in other systems to obtain signals insensitive to B0 field inhomogeneity. In the present study, we employed an iDQC approach to enhance the spectral resolution of RBM. The feasibility and performance of this method for achieving high resolution MRS was verified by experiments on phantoms and pig vertebral bone samples. Unsaturated fatty acid peaks which overlap in the conventional MRS were well resolved and identified in the iDQC spectrum. Quantitative comparison of fractions of three types of fatty acids was performed between iDQC spectra on the in situ RMB and conventional MRS on the extracted fat from the same RBM. Observations of unsaturated fatty acids with iDQC MRS may provide valuable information and may hold potential in diagnosis of diseases such as obesity, diabetes, and leukemia.

  20. Comparison of a restrictive versus liberal red cell transfusion policy for patients with myelodysplasia, aplastic anaemia, and other congenital bone marrow failure disorders

    PubMed Central

    Gu, Yisu; Estcourt, Lise J; Doree, Carolyn; Trivella, Marialena; Hopewell, Sally; Vyas, Paresh

    2015-01-01

    This is the protocol for a review and there is no abstract. The objectives are as follows: To assess the efficacy and safety of a restrictive versus liberal red cell transfusion strategy for patients with long-term bone marrow failure. These include myelodysplasia, acquired aplastic anaemia, and other inherited bone marrow failure disorders. PMID:25983657

  1. Influence of age, sex and calendar year on lifetime accumulated red bone marrow dose from diagnostic radiation exposure.

    PubMed

    Hoffmann, Wolfgang; Meiboom, Merle Friederike; Weitmann, Kerstin; Terschüren, Claudia; von Boetticher, Heiner

    2013-01-01

    Our aim is to evaluate the relevance of different factors influencing lifetime accumulated red bone marrow dose, such as calendar year, age and sex. The lifetime dose was estimated for controls interviewed in person (N = 2811, 37.5% women) of the population-based representative Northern Germany Leukemia and Lymphoma Study. Data were assessed in standardized computer-assisted personal interviews. The calculation of doses is based on a comprehensive quantification model including calendar year, sex, kind of examination, and technical development. In multivariate regression models the annual red bone marrow dose was analyzed depending on age, sex and calendar year to consider simultaneously temporal changes in radiologic practice and individual risk factors. While the number of examinations continuously rises over time, the dose shows two peaks around 1950 and after 1980. Men are exposed to higher doses than woman. Until 1970 traditional examinations like conventional and mass screening examinations caused the main dose. They were then replaced by technically advanced examinations mainly computed tomography and cardiac catheter. The distribution of the red bone marrow dose over lifetime depends highly on the technical standards and radiation protection survey. To a lesser extent it is influenced by age and sex of the subjects. Thus epidemiological studies concerning the assessment of radiation exposure should consider the calendar year in which the examination was conducted.

  2. Minor histocompatibility antigens on transfused leukoreduced units of red blood cells induce bone marrow transplant rejection in a mouse model.

    PubMed

    Desmarets, Maxime; Cadwell, Chantel M; Peterson, Kenneth R; Neades, Renee; Zimring, James C

    2009-09-10

    When successful, human leukocyte antigen (HLA)-matched bone marrow transplantation with reduced-intensity conditioning is a cure for several nonmalignant hematologic disorders that require chronic transfusion, such as sickle cell disease and aplastic anemia. However, there are unusually high bone marrow transplant (BMT) rejection rates in these patients. Rejection correlates with the number of transfusions before bone marrow transplantation, and it has been hypothesized that preimmunization to antigens on transfused blood may prime BMT rejection. Using a novel mouse model of red blood cell (RBC) transfusion and major histocompatibility complex-matched bone marrow transplantation, we report that transfusion of RBC products induced BMT rejection across minor histocompatibility antigen (mHA) barriers. It has been proposed that contaminating leukocytes are responsible for transfusion-induced BMT rejection; however, filter leukoreduction did not prevent rejection in the current studies. Moreover, we generated a novel transgenic mouse with RBC-specific expression of a model mHA and demonstrated that transfusion of RBCs induced a CD8(+) T-cell response. Together, these data suggest that mHAs on RBCs themselves are capable of inducing BMT rejection. Cellular immunization to mHAs is neither monitored nor managed by current transfusion medicine practice; however, the current data suggest that mHAs on RBCs may represent an unappreciated and significant consequence of RBC transfusion.

  3. Microdosimetry of astatine-211 using histological images: application to bone marrow.

    PubMed

    Akabani, G; Zalutsky, M R

    1997-12-01

    A method is presented for calculating the small-scale dosimetry of 211At in red bone marrow using chord-length distributions obtained from digitized histological images. This study used histological samples of bone marrow from beagle dogs to convey morphological information about cell conglomerations within bone marrow. Two 211At activity distributions were considered within the extracellular fluid and the surface of red bone marrow cells. Results confirmed the influence of cell conglomeration and activity distribution in determining the microdosimetry of red bone marrow. Average S* values of 1.6 x 10(-9) and 1.90 x 10(-9) Gy g Bq(-1) s(-1) were calculated for activity distributions located within the extracellular fluid and the surface of red bone marrow cells, respectively. The cumulated activity required to reduce survival probability to 0.37 also was calculated as a function of cell sensitivity for both activity distributions. The activity distribution on the cell surface resulted in a higher cell-killing efficiency, requiring a lower activity concentration of approximately 25% when compared with activity located in the extracellular fluid. Of relevance to potential clinical studies with 211At, the probability for zero hits for red bone marrow cells was > 10% for cumulated activities of less than 5.5 x 10(8) Bq s g(-1) in bone marrow.

  4. Red bone marrow dose calculations in radiotherapy of prostate cancer based on the updated VCH adult male phantom

    NASA Astrophysics Data System (ADS)

    Ai, Jinqin; Xie, Tianwu; Sun, Wenjuan; Liu, Qian

    2014-04-01

    Red bone marrow (RBM) is an important dose-limiting tissue that has high radiosensitivity but is difficult to identify on clinical medical images. In this study, we investigated dose distribution in RBM for prostate cancer radiotherapy. Four suborgans were identified in the skeleton of the visible Chinese human phantom: cortical bone (CB), trabecular bone (TB), RBM, and yellow bone marrow (YBM). Dose distributions in the phantom were evaluated by the Monte Carlo method. When the left os coxae was taken as the organ-at-risk (OAR), the difference in absorbed dose between RBM and each CB and TB was up to 20%, but was much less (≤3.1%) between RBM and YBM. When the left os coxae and entire bone were both taken as OARs, RBM dose also increased with increasing planning target volume size. The results indicate the validity of using dose to homogeneous bone marrow mixture for estimating dose to RBM when RBM is not available in computational phantoms. In addition, the human skeletal system developed in this study provides a model for considering RBM dose in radiotherapy planning.

  5. Engraftment of bone marrow transplants in W anemic mice measured by electronic determination of the red blood cell size profile.

    PubMed

    Wiktor-Jedrzejczak, W; Sharkis, S J; Ahmed, A; Sensenbrenner, L L; Sell, K W

    1979-09-01

    Defective stem cells of WBB6F1-W/Wv mice produce macrocytic red blood cells (RBCs); stem cells of WBB6F1-+/+ mice produce normocytic RBCs. Utilization of the Coulter counter channelyzer permitted good dissociation between the size distribution of populations of +/+ and W/Wv RBCs. Peaks (mean cell volumes) for +/+ and W/Wv RBCs have been determined to be between the 30th and 40th channel and 50th and 60th channel, respectively. Variability of profiles for individual mice of both genotypes did not exceed the variability of separate determinations of the same cell suspension from a single mouse. Admixture (approximately 15%) of either type of erythrocytes could be quantitatively detected by this method. One week after transplant of 10(7) +/+ marrow cells into W/Wv recipients, 25% of donor type erythrocytes were detected. Eighteen days post-graft, concentration of +/- normocytes exceeded the concentration of macrocytes in the W/Wv recipients' circulation. Approximately 45 days post-transplant, the proportion of macrocytes decreased below the 10% detectable level. Calculation of the daily RBC production rate during repopulation and estimation of the number of RBCs produced by a single hematopoietic colony were determined. The RBC size profile was found to be a convenient method for studying the effect of implantation of W/Wv marrow into lethally irradiated +/+ mice. This method proved suitable for repetitive determination of the size population in individual transplanted mice.

  6. Genotoxicity studies on the azo dye Direct Red 2 using the in vivo mouse bone marrow micronucleus test.

    PubMed

    Rajaguru, P; Fairbairn, L J; Ashby, J; Willington, M A; Turner, S; Woolford, L A; Chinnasamy, N; Rafferty, J A

    1999-07-21

    The clastogenicity of the azo dye Direct Red 2 (DR2) has been investigated using the murine bone marrow micronucleus assay. A potent dose-dependent response was observed following oral gavage of DR2 up to 4 mg/kg, after which significant toxicity to the erythroid compartment was observed. The route of administration had a significant effect on the frequency of micronucleus formation: intraperitoneal injection was approximately two-fold less clastogenic than the equivalent dose delivered orally (p<0.05). The requirement for activation of DR2 by intestinal microflora was indicated by the fact that mice given acid-treated water prior to administration of DR2 showed a significant reduction (40%; p<0.001) in micronucleated polychromatic erythrocyte formation. The implications of these findings for the health and safety of occupationally exposed workers are discussed.

  7. A bone marrow toxicity model for 223Ra alpha-emitter radiopharmaceutical therapy

    NASA Astrophysics Data System (ADS)

    Hobbs, Robert F.; Song, Hong; Watchman, Christopher J.; Bolch, Wesley E.; Aksnes, Anne-Kirsti; Ramdahl, Thomas; Flux, Glenn D.; Sgouros, George

    2012-05-01

    Ra-223, an α-particle emitting bone-seeking radionuclide, has recently been used in clinical trials for osseous metastases of prostate cancer. We investigated the relationship between absorbed fraction-based red marrow dosimetry and cell level-dosimetry using a model that accounts for the expected localization of this agent relative to marrow cavity architecture. We show that cell level-based dosimetry is essential to understanding potential marrow toxicity. The GEANT4 software package was used to create simple spheres representing marrow cavities. Ra-223 was positioned on the trabecular bone surface or in the endosteal layer and simulated for decay, along with the descendants. The interior of the sphere was divided into cell-size voxels and the energy was collected in each voxel and interpreted as dose cell histograms. The average absorbed dose values and absorbed fractions were also calculated in order to compare those results with previously published values. The absorbed dose was predominantly deposited near the trabecular surface. The dose cell histogram results were used to plot the percentage of cells that received a potentially toxic absorbed dose (2 or 4 Gy) as a function of the average absorbed dose over the marrow cavity. The results show (1) a heterogeneous distribution of cellular absorbed dose, strongly dependent on the position of the cell within the marrow cavity; and (2) that increasing the average marrow cavity absorbed dose, or equivalently, increasing the administered activity resulted in only a small increase in potential marrow toxicity (i.e. the number of cells receiving more than 4 or 2 Gy), for a range of average marrow cavity absorbed doses from 1 to 20 Gy. The results from the trabecular model differ markedly from a standard absorbed fraction method while presenting comparable average dose values. These suggest that increasing the amount of radioactivity may not substantially increase the risk of toxicity, a result unavailable to the

  8. Internal radiation dosimetry for clinical testing of radiolabeled monoclonal antibodies

    SciTech Connect

    Fisher, D.R.; Durham, J.S.; Hui, T.E.; Hill, R.L.

    1990-11-01

    In gauging the efficacy of radiolabeled monoclonal antibodies in cancer treatment, it is important to know the amount of radiation energy absorbed by tumors and normal tissue per unit administered activity. This paper describes methods for estimating absorbed doses to human tumors and normal tissues, including intraperitoneal tissue surfaces, red marrow, and the intestinal tract from incorporated radionuclides. These methods use the Medical Internal Radiation Dose (MIRD) scheme; however, they also incorporate enhancements designed to solve specific dosimetry problems encountered during clinical studies, such as patient-specific organ masses obtained from computerized tomography (CT) volumetrics, estimates of the dose to tumor masses within normal organs, and multicellular dosimetry for studying dose inhomogeneities in solid tumors. Realistic estimates of absorbed dose are provided within the short time requirements of physicians so that decisions can be made with regard to patient treatment and procurement of radiolabeled antibodies. Some areas in which further research could improve dose assessment are also discussed. 16 refs., 3 figs.

  9. SU-E-T-121: Dosimetric Characterization of Gafchromic Film EBT3 Using Vidar DosimetryPro Advantage RED and EPSON Expression 10000XL Scanners

    SciTech Connect

    Medina, L; Adrada, A; Filipuzzi, M; Garrigo, E; Venencia, C

    2014-06-01

    Purpose: The purpose of this paper is to characterize EBT3 using two types of scanner, analyzing the factors of influence of each dosimetry system. Methods: The film used in this study was GAFCHROMIC EBT3, the films were exposed at a dose range between 0Gy a 9Gy in a solid water phantom, SSD=100cm, 5cm depth and perpendicularly to the 6MV photon beam generated by a Novalis TX linear accelerator equipped with an HDMLC. A Farmer type ion chamber TN30013 (PTW) was used to determine the dose delivered to the film. The films were digitized with a scanner EPSON expression 10000XL and the VIDAR DosimetryPro Adventage RED. Software RIT113v6.1 was used for construction of the calibration curve and analysis. The film characteristics investigated were: response at different dose levels, sensitivity to orientation and side and resolution through the results of the spatial response function by analyzing a step pattern. Additionally, 20 IMRT treatment fields were measured with both scanner and compared with calculated dose using gamma index analysis (3%-3mm). Results: The OD obtained for dose level 2Gy in the orientation portrait of the film on the scanner EPSON is (0,222±0,19) and for Vidar RED (0,252±0,10) and landscape is for EPSON (0,211±0,25) and for Vidar RED (0,250±0,11) . The orientation dependence with respect to film side is about 0,09% for EPSON and about 0.03% for VIDAR. The spatial response function increase in response to the Gaussian function FWHM EPSON scanner (0.18mm) compared with VIDAR scanner function (less than 0.06mm) was observed. We analyzed 20 total plan dose distributions the number of pixels with gamma>1 (3%-3mm) was 0.7%±1.2 [0.1%; 2.82%] for EBT3-VIDAR y 2%±2.9 [0.2%; 3.5%] for EBT3-EPSON. Conclusion: VIDAR scanner shows better sensitivity. EBT3 film shows a different response between portrait and landscape orientation. Step pattern is better reproduce by VIDAR scanner.

  10. Dual-channel red/blue fluorescence dosimetry with broadband reflectance spectroscopic correction measures protoporphyrin IX production during photodynamic therapy of actinic keratosis

    NASA Astrophysics Data System (ADS)

    Kanick, Stephen Chad; Davis, Scott C.; Zhao, Yan; Hasan, Tayyaba; Maytin, Edward V.; Pogue, Brian W.; Chapman, M. Shane

    2014-07-01

    Dosimetry for aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) photodynamic therapy of actinic keratosis was examined with an optimized fluorescence dosimeter to measure PpIX during treatment. While insufficient PpIX generation may be an indicator of incomplete response, there exists no standardized method to quantitate PpIX production at depths in the skin during clinical treatments. In this study, a spectrometer-based point probe dosimeter system was used to sample PpIX fluorescence from superficial (blue wavelength excitation) and deeper (red wavelength excitation) tissue layers. Broadband white light spectroscopy (WLS) was used to monitor aspects of vascular physiology and inform a correction of fluorescence for the background optical properties. Measurements in tissue phantoms showed accurate recovery of blood volume fraction and reduced scattering coefficient from WLS, and a linear response of PpIX fluorescence versus concentration down to 1.95 and 250 nM for blue and red excitations, respectively. A pilot clinical study of 19 patients receiving 1-h ALA incubation before treatment showed high intrinsic variance in PpIX fluorescence with a standard deviation/mean ratio of >0.9. PpIX fluorescence was significantly higher in patients reporting higher pain levels on a visual analog scale. These pilot data suggest that patient-specific PpIX quantitation may predict outcome response.

  11. Dual-channel red/blue fluorescence dosimetry with broadband reflectance spectroscopic correction measures protoporphyrin IX production during photodynamic therapy of actinic keratosis

    PubMed Central

    Kanick, Stephen Chad; Davis, Scott C.; Zhao, Yan; Hasan, Tayyaba; Maytin, Edward V.; Pogue, Brian W.; Chapman, M. Shane

    2014-01-01

    Abstract. Dosimetry for aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) photodynamic therapy of actinic keratosis was examined with an optimized fluorescence dosimeter to measure PpIX during treatment. While insufficient PpIX generation may be an indicator of incomplete response, there exists no standardized method to quantitate PpIX production at depths in the skin during clinical treatments. In this study, a spectrometer-based point probe dosimeter system was used to sample PpIX fluorescence from superficial (blue wavelength excitation) and deeper (red wavelength excitation) tissue layers. Broadband white light spectroscopy (WLS) was used to monitor aspects of vascular physiology and inform a correction of fluorescence for the background optical properties. Measurements in tissue phantoms showed accurate recovery of blood volume fraction and reduced scattering coefficient from WLS, and a linear response of PpIX fluorescence versus concentration down to 1.95 and 250 nM for blue and red excitations, respectively. A pilot clinical study of 19 patients receiving 1-h ALA incubation before treatment showed high intrinsic variance in PpIX fluorescence with a standard deviation/mean ratio of >0.9. PpIX fluorescence was significantly higher in patients reporting higher pain levels on a visual analog scale. These pilot data suggest that patient-specific PpIX quantitation may predict outcome response. PMID:24996661

  12. Factors affecting the relationship between the red marrow dose and myelotoxicity in patients receiving radioimmunotherapy with {sup 131}I-labeled anti-CEA monoclonal antibodies

    SciTech Connect

    Juweid, M.; Behr, T.M.; Sharkey, R.M.

    1996-05-01

    This study examined the relationship between the red marrow dose (RMD) and myelotoxicity in patients with CEA-producing tumors who received radioimmunotherapy (RAIT) with {sup 131}I-NP-4 and MN-14 anti-CEA MAbs. Eligibility criteria included no chemotherapy in the last 4 weeks prior to RAIT, no X-irradiation (XT) to >25% of marrow, WBC >3,000, platelets > 100,000, and Hg > 10.0. The RMD was estimated based on blood by assuming a red marrow-to-blood activity concentration ratio of 1.0. Myelotoxicity was evaluated based on standard RTOG criteria. Leukopenia or thrombocytopenia {ge} grade 3 was considered dose-limiting toxicity (DLT). A total of 109 eligible patients were assessed for myelotoxicity. Overall, reversible DLT occurred in 0/14 (0%), 1/25 (4%), 4/26 (15%), 6/25 (24%), 5/9 (55%), 3/6 (50%), and 3/4 (75%) patients receiving a mean RMD of 75, 150, 250, 350, 450, 550, and 650 cGy, respectively. Patients were further stratified into those who had chemotherapy (CHT) in the last 1-6 months prior to RAIT, and/or had XT or tumor metastases to 11-25% of their marrow (group 1), and those who had no CHT in the last 6 months and/or XT or metastases to {ge} 10% of the marrow (group 2). At 250, 350, 450, and 550 cGy, the incidence of DLT in group 1 was 4/17 (23%), 5/11 (45%), 4/4 (100%), and 3/3 (100%), respectively, compared to 0/9 (0%), 1/14 (7%), 1/5 (20%), and 0/3 (0%) in group 2. In conclusion, these data indicate that recent CHT, XT, and marrow metastases are important factors determining myelotoxicity after RAIT. Further, the relatively low incidence of myelotoxicity in group 2 (1/8, 12/5%) DLT at a RMD of 450-550cGy suggests that these patients may be able to tolerate an almost 2-fold higher dose than those in group 1. Although further refinement in identifying risk-factors for myelotoxicity are necessary, these results provide important insights for future planning of phase II trials.

  13. Estimating 131I biokinetics and radiation doses to the red marrow and whole body in thyroid cancer patients: probe detection versus image quantification*

    PubMed Central

    Willegaignon, José; Pelissoni, Rogério Alexandre; Lima, Beatriz Christine de Godoy Diniz; Sapienza, Marcelo Tatit; Coura-Filho, George Barberio; Queiroz, Marcelo Araújo; Buchpiguel, Carlos Alberto

    2016-01-01

    Objective To compare the probe detection method with the image quantification method when estimating 131I biokinetics and radiation doses to the red marrow and whole body in the treatment of thyroid cancer patients. Materials and Methods Fourteen patients with metastatic thyroid cancer, without metastatic bone involvement, were submitted to therapy planning in order to tailor the therapeutic amount of 131I to each individual. Whole-body scans and probe measurements were performed at 4, 24, 48, 72, and 96 h after 131I administration in order to estimate the effective half-life (Teff) and residence time of 131I in the body. Results The mean values for Teff and residence time, respectively, were 19 ± 9 h and 28 ± 12 h for probe detection, compared with 20 ± 13 h and 29 ± 18 h for image quantification. The average dose to the red marrow and whole body, respectively, was 0.061 ± 0.041 mGy/MBq and 0.073 ± 0.040 mGy/MBq for probe detection, compared with 0.066 ± 0.055 mGy/MBq and 0.078 ± 0.056 mGy/MBq for image quantification. Statistical analysis proved that there were no significant differences between the two methods for estimating the Teff (p = 0.801), residence time (p = 0.801), dose to the red marrow (p = 0.708), and dose to the whole body (p = 0.811), even when we considered an optimized approach for calculating doses only at 4 h and 96 h after 131I administration (p > 0.914). Conclusion There is full agreement as to the feasibility of using probe detection and image quantification when estimating 131I biokinetics and red-marrow/whole-body doses. However, because the probe detection method is inefficacious in identifying tumor sites and critical organs during radionuclide therapy and therefore liable to skew adjustment of the amount of 131I to be administered to patients under such therapy, it should be used with caution. PMID:27403014

  14. Computational dosimetry

    SciTech Connect

    Siebert, B.R.L.; Thomas, R.H.

    1996-01-01

    The paper presents a definition of the term ``Computational Dosimetry`` that is interpreted as the sub-discipline of computational physics which is devoted to radiation metrology. It is shown that computational dosimetry is more than a mere collection of computational methods. Computational simulations directed at basic understanding and modelling are important tools provided by computational dosimetry, while another very important application is the support that it can give to the design, optimization and analysis of experiments. However, the primary task of computational dosimetry is to reduce the variance in the determination of absorbed dose (and its related quantities), for example in the disciplines of radiological protection and radiation therapy. In this paper emphasis is given to the discussion of potential pitfalls in the applications of computational dosimetry and recommendations are given for their avoidance. The need for comparison of calculated and experimental data whenever possible is strongly stressed.

  15. Comparison of a restrictive versus liberal red cell transfusion policy for patients with myelodysplasia, aplastic anaemia, and other congenital bone marrow failure disorders

    PubMed Central

    Gu, Yisu; Estcourt, Lise J; Doree, Carolyn; Hopewell, Sally; Vyas, Paresh

    2015-01-01

    Background Bone marrow failure disorders include a heterogenous group of disorders, of which myelodysplastic syndrome (MDS), forms the largest subgroup. MDS is predominantly a disease of the elderly, with many elderly people managed conservatively with regular allogeneic red blood cell (RBC) transfusions to treat their anaemia. However, RBC transfusions are not without risk. Despite regular transfusions playing a central role in treating such patients, the optimal RBC transfusion strategy (restrictive versus liberal) is currently unclear. Objectives To assess the efficacy and safety of a restrictive versus liberal red blood cell transfusion strategy for patients with myelodysplasia, acquired aplastic anaemia, and other inherited bone marrow failure disorders. Search methods We searched for randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2015, Issue 4), Ovid MEDLINE (from 1946), Ovid EMBASE (from 1974), EBSCO CINAHL (from 1937), the Transfusion Evidence Library (from 1980) and ongoing trial databases to 26th May 2015. Selection criteria RCTs including patients with long-term bone marrow failure disorders that require allogeneic blood transfusion, who are not being actively treated with a haematopoietic stem cell transplant, or intensive chemotherapy. Data collection and analysis We used standard Cochrane review methodology. One author initially screened all references, and excluded any that were clearly irrelevant or duplicates. Two authors then independently screened all abstracts of articles, identified by the review search strategy, for relevancy. Two authors independently assessed the full text of all potentially relevant articles for eligibility, completed the data extraction and assessed the studies for risk of bias using The Cochrane Collaboration’s ’Risk of bias’ tool. Main results We included one trial (13 participants) and identified three ongoing trials that assess RBC

  16. Flow cytometric evaluation of red blood cell chimerism after bone marrow transplantation in Iranian patients: a preliminary study.

    PubMed

    Shaiegan, Mojgan; Hadjati, Esmerdis; Aghaiipour, Mahnaz; Iravani, Masoud; David, Gaelle; Bernard, Daniel

    2006-10-01

    The aim of this study was to evaluate mixed red cells population and red blood cell chimerism after hematopoietic stem cell transplantation. Red blood cell chimerism after hematopoietic stem cell transplantation was analyzed using a series of fluorescein isothiocyanate-conjugated monoclonal antibodies (BioAtlantic, France) directed against ABH, Rh (D, C, E, c, e), Kell, Duffy, Kidd, and Ss antigens on blood samples of 14 patients with hematologic disorders undergoing hematopoietic stem cell transplantation, by flow cytometric method on days 15, 30, and 60 after transplantation. All patients showed expression of donor red cell antigens within days 15 - 30 after hematopoietic stem cell transplantation. Graft versus host disease and ABO incompatibility did not affect the expression of chimerism. Flow cytometric analysis is a simple, accurate, and valuable test which is of significant help in monitoring chimerism in allogeneic hematopoietic stem cell transplantation.

  17. (Biological dosimetry)

    SciTech Connect

    Sega, G.A.

    1990-11-06

    The traveler participated in an International Symposium on Trends in Biological Dosimetry and presented an invited paper entitled, Adducts in sperm protamine and DNA vs mutation frequency.'' The purpose of the Symposium was to examine the applicability of new methods to study quantitatively the effects of xenobiotic agents (radiation and chemicals) on molecular, cellular and organ systems, with special emphasis on human biological dosimetry. The general areas covered at the meeting included studies on parent compounds and metabolites; protein adducts; DNA adducts; gene mutations; cytogenetic end-points and reproductive methods.

  18. Excess of veno-occlusive disease in a randomized clinical trial on a higher trigger for red blood cell transfusion after bone marrow transplantation: a canadian blood and marrow transplant group trial.

    PubMed

    Robitaille, Nancy; Lacroix, Jacques; Alexandrov, Lubomir; Clayton, Lucy; Cortier, Marion; Schultz, Kirk R; Bittencourt, Henrique; Duval, Michel

    2013-03-01

    Previous studies have shown that maintaining high hemoglobin levels in patients after chemotherapy reduced the length of neutropenia. Thus, we undertook a randomized, controlled, clinical trial in children undergoing allogeneic bone marrow transplantation after receiving a myeloablative conditioning regimen to compare 2 hemoglobin thresholds as triggers for red blood cell transfusion: 120 g/L in the experimental arm and 70 g/L in the control arm. The Data and Safety Monitoring Board closed the study after enrollment of the sixth patient because 3 patients in the experimental arm contracted veno-occlusive disease, but none in the control arm did (P = .05). Ascites was present in all 3 patients, pleura effusion in 2, and portal vein thrombosis in 2. One patient experienced hepatic failure and required treatment with the molecular adsorbent recycling system. Another patient required hemodialysis for renal failure. No major imbalance between groups was seen with regard to risk factors for veno-occlusive disease. Therefore, maintaining the hemoglobin at higher levels should be avoided after hematopoietic stem cell transplantation.

  19. (Biological dosimetry)

    SciTech Connect

    Preston, R.J.

    1990-12-17

    The traveler attended the 1st International Conference on Biological Dosimetry in Madrid, Spain. This conference was organized to provide information to a general audience of biologists, physicists, radiotherapists, industrial hygiene personnel and individuals from related fields on the current ability of cytogenetic analysis to provide estimates of radiation dose in cases of occupational or environmental exposure. There is a growing interest in Spain in biological dosimetry because of the increased use of radiation sources for medical and occupational uses, and with this the anticipated and actual increase in numbers of overexposure. The traveler delivered the introductory lecture on Biological Dosimetry: Mechanistic Concepts'' that was intended to provide a framework by which the more applied lectures could be interpreted in a mechanistic way. A second component of the trip was to provide advice with regard to several recent cases of overexposure that had been or were being assessed by the Radiopathology and Radiotherapy Department of the Hospital General Gregorio Maranon'' in Madrid. The traveler had provided information on several of these, and had analyzed cells from some exposed or purportedly exposed individuals. The members of the biological dosimetry group were referred to individuals at REACTS at Oak Ridge Associated Universities for advice on follow-up treatment.

  20. Neutron personnel dosimetry

    SciTech Connect

    Griffith, R.V.

    1981-06-16

    The current state-of-the-art in neutron personnel dosimetry is reviewed. Topics covered include dosimetry needs and alternatives, current dosimetry approaches, personnel monitoring devices, calibration strategies, and future developments. (ACR)

  1. Bone marrow histopathology in the diagnostic evaluation of splenic marginal-zone and splenic diffuse red pulp small B-cell lymphoma: a reliable substitute for spleen histopathology?

    PubMed

    Ponzoni, Maurilio; Kanellis, George; Pouliou, Evi; Baliakas, Panagiotis; Scarfò, Lydia; Ferreri, Andrés J M; Doglioni, Claudio; Bikos, Vasilis; Dagklis, Antonis; Anagnostopoulos, Achilles; Ghia, Paolo; Stamatopoulos, Kostas; Papadaki, Theodora

    2012-11-01

    Primary splenic small B-cell lymphomas mostly comprise the distinct entity of splenic marginal-zone lymphoma (SMZL) and the provisional category of splenic lymphoma/leukemia unclassifiable, mainly represented by the hairy cell leukemia variant and splenic diffuse red pulp small B-cell lymphoma (SDRL). Until recently, histopathologic examination of splenectomy specimens was considered mandatory for the diagnosis of SMZL. However, nowadays, mainly because of advances in chemoimmunotherapy, splenectomy is performed much less frequently. We evaluated the diagnostic efficacy of bone marrow biopsy (BMB) histopathology in the diagnostic approach toward SMZL and SDRL and tested whether it may serve as a substitute for spleen histopathology in the differential diagnosis between these 2 entities. To this end, we conducted a paired assessment of BMB and spleen diagnostic samples from 46 cases with a diagnosis of SMZL (n=32) or SDRL (n=14) based on spleen histopathology. We demonstrate that detailed immunohistopathologic BMB evaluation offers adequate evidence for the confirmation of these entities and their differential diagnosis from other small B-cell lymphoma histotypes. Notably, the immunophenotypical profile of SMZL and SDRL was identical in both BMB and spleen specimens for 21 evaluated markers. Paired assessment of BMB and spleen specimens did not identify discriminating patterns of BMB infiltration, cytology, and/or immunohistology between SMZL and SDRL. Accordingly, bone marrow histopathology contributes significantly in confirming the diagnosis of SMZL and SDRL. However, presently it is not possible to distinguish SMZL from SDRL on the basis of BMB evaluation alone; hence, histopathologic examination of the spleen remains the "gold standard" approach.

  2. Establishment of a γ-H2AX foci-based assay to determine biological dose of radon to red bone marrow in rats

    PubMed Central

    Wang, Jing; He, Linfeng; Fan, Dunhuang; Ding, Defang; Wang, Xufei; Gao, Yun; Zhang, Xuxia; Li, Qiang; Chen, Honghong

    2016-01-01

    The biodosimetric information is critical for assessment of cancer risk in populations exposed to high radon. However, no tools are available for biological dose estimation following radon exposure. Here, we established a γ-H2AX foci-based assay to determine biological dose to red bone marrow (RBM) in radon-inhaled rats. After 1–3 h of in vitro radon exposure, a specific pattern of γ-H2AX foci, linear tracks with individual p-ATM and p-DNA-PKcs foci, was observed, and the yield of γ-H2AX foci and its linear tracks displayed a linear dose-response manner in both rat peripheral blood lymphocytes (PBLs) and bone-marrow lymphocytes (BMLs). When the cumulative doses of radon inhaled by rats reached 14, 30 and 60 working level months (WLM), the yields of three types of foci markedly increased in both PBLs and BMLs, and γ-H2AX foci-based dose estimates to RBM were 0.97, 2.06 and 3.94 mGy, respectively. Notably, BMLs displayed a more profound increase of three types of foci than PBLs, and the absorbed dose ratio between BMLs and PBLs was similar between rats exposed to 30 and 60 WLM of radon. Taken together, γ-H2AX foci quantitation in PBLs is able to estimate RBM-absorbed doses with the dose-response curve of γ-H2AX foci after in vitro radon exposure and the ratio of RBM- to PBL-absorbed doses in rats following radon exposure. PMID:27445126

  3. Establishment of a γ-H2AX foci-based assay to determine biological dose of radon to red bone marrow in rats

    NASA Astrophysics Data System (ADS)

    Wang, Jing; He, Linfeng; Fan, Dunhuang; Ding, Defang; Wang, Xufei; Gao, Yun; Zhang, Xuxia; Li, Qiang; Chen, Honghong

    2016-07-01

    The biodosimetric information is critical for assessment of cancer risk in populations exposed to high radon. However, no tools are available for biological dose estimation following radon exposure. Here, we established a γ-H2AX foci-based assay to determine biological dose to red bone marrow (RBM) in radon-inhaled rats. After 1–3 h of in vitro radon exposure, a specific pattern of γ-H2AX foci, linear tracks with individual p-ATM and p-DNA-PKcs foci, was observed, and the yield of γ-H2AX foci and its linear tracks displayed a linear dose-response manner in both rat peripheral blood lymphocytes (PBLs) and bone-marrow lymphocytes (BMLs). When the cumulative doses of radon inhaled by rats reached 14, 30 and 60 working level months (WLM), the yields of three types of foci markedly increased in both PBLs and BMLs, and γ-H2AX foci-based dose estimates to RBM were 0.97, 2.06 and 3.94 mGy, respectively. Notably, BMLs displayed a more profound increase of three types of foci than PBLs, and the absorbed dose ratio between BMLs and PBLs was similar between rats exposed to 30 and 60 WLM of radon. Taken together, γ-H2AX foci quantitation in PBLs is able to estimate RBM-absorbed doses with the dose-response curve of γ-H2AX foci after in vitro radon exposure and the ratio of RBM- to PBL-absorbed doses in rats following radon exposure.

  4. Radiation dosimetry.

    PubMed Central

    Cameron, J

    1991-01-01

    This article summarizes the basic facts about the measurement of ionizing radiation, usually referred to as radiation dosimetry. The article defines the common radiation quantities and units; gives typical levels of natural radiation and medical exposures; and describes the most important biological effects of radiation and the methods used to measure radiation. Finally, a proposal is made for a new radiation risk unit to make radiation risks more understandable to nonspecialists. PMID:2040250

  5. Bone marrow aspiration

    MedlinePlus

    Iliac crest tap; Sternal tap; Leukemia - bone marrow aspiration; Aplastic anemia - bone marrow aspiration; Myelodysplastic syndrome - bone marrow aspiration; Thrombocytopenia - bone marrow aspiration; Myelofibrosis - bone marrow aspiration

  6. The Mayak Worker Dosimetry System (MWDS-2013): Internal Dosimetry Results.

    PubMed

    Vostrotin, Vadim; Birchall, Alan; Zhdanov, Alexey; Puncher, Matthew; Efimov, Alexander; Napier, Bruce; Sokolova, Alexandra; Miller, Scott; Suslova, Klara

    2016-09-24

    The distribution of calculated internal doses has been determined for 8043 Mayak Production Associate (Mayak PA) workers. This is a subset of the entire cohort of 25 757 workers, for whom monitoring data are available. Statistical characteristics of point estimates of accumulated doses to 17 different tissues and organs and the uncertainty ranges were calculated. Under the MWDS-2013 dosimetry system, the mean accumulated lung dose was 185 ± 594 mGy (geometric mean = 28 mGy; geometric standard deviation = 9.32; median value = 31 mGy; maximum value = 8980 mGy). The ranges of relative standard uncertainty were from 40 to 2200% for accumulated lung dose, from 25-90% to 2600-3000% for accumulated dose to different regions of respiratory tract, from 13-22% to 2300-2500% for systemic organs and tissues. The Mayak PA workers accumulated internal plutonium lung dose is shown to be close to log normal. The accumulated internal plutonium dose to systemic organs was close to a log triangle. The dependency of uncertainty of accumulated absorbed lung and liver doses on the dose estimates itself is also shown. The accumulated absorbed doses to lung, alveolar-interstitial region, liver, bone surface cells and red bone marrow calculated both with MWDS-2013 and MWDS-2008 have been compared. In general, the accumulated lung doses increased by a factor of 1.8 in median value, while the accumulated doses to systemic organs decreased by factor of 1.3-1.4 in median value. For the cases with identical initial data, accumulated lung doses increased by a factor of 2.1 in median value, while accumulated doses to systemic organs decreased by 8-13% in median value. For the cases with both identical initial data and all of plutonium activity in urine measurements above the decision threshold, accumulated lung doses increased by a factor of 2.7 in median value, while accumulated doses to systemic organs increased by 6-12% in median value.

  7. Fourth international radiopharmaceutical dosimetry symposium

    SciTech Connect

    Schlafke-Stelson, A.T.; Watson, E.E.

    1986-04-01

    The focus of the Fourth International Radiopharmaceutical Dosimetry Symposium was to explore the impact of current developments in nuclear medicine on absorbed dose calculations. This book contains the proceedings of the meeting including the edited discussion that followed the presentations. Topics that were addressed included the dosimetry associated with radiolabeled monoclonal antibodies and blood elements, ultrashort-lived radionuclides, and positron emitters. Some specific areas of discussion were variations in absorbed dose as a result of alterations in the kinetics, the influence of radioactive contaminants on dose, dose in children and in the fetus, available instrumentation and techniques for collecting the kinetic data needed for dose calculation, dosimetry requirements for the review and approval of new radiopharmaceuticals, and a comparison of the effect on the thyroid of internal versus external irradiation. New models for the urinary blader, skeleton including the active marrow, and the blood were presented. Several papers dealt with the validity of traditional ''average-organ'' dose estimates to express the dose from particulate radiation that has a short range in tissue. These problems are particularly important in the use of monoclonal antibodies and agents used to measure intracellular functions. These proceedings have been published to provide a resource volume for anyone interested in the calculation of absorbed radiation dose.

  8. Extension of the biological effective dose to the MIRD schema and possible implications in radionuclide therapy dosimetry

    SciTech Connect

    Baechler, Sebastien; Hobbs, Robert F.; Prideaux, Andrew R.; Wahl, Richard L.; Sgouros, George

    2008-03-15

    In dosimetry-based treatment planning protocols, patients with rapid clearance of the radiopharmaceutical require a larger amount of initial activity than those with slow clearance to match the absorbed dose to the critical organ. As a result, the dose-rate to the critical organ is higher in patients with rapid clearance and may cause unexpected toxicity compared to patients with slow clearance. In order to account for the biological impact of different dose-rates, radiobiological modeling is beginning to be applied to the analysis of radionuclide therapy patient data. To date, the formalism used for these analyses is based on kinetics derived from activity in a single organ, the target. This does not include the influence of other source organs to the dose and dose-rate to the target organ. As a result, only self-dose irradiation in the target organ contributes to the dose-rate. In this work, the biological effective dose (BED) formalism has been extended to include the effect of multiple source organ contributions to the net dose-rate in a target organ. The generalized BED derivation has been based on the Medical Internal Radionuclide Dose Committee (MIRD) schema assuming multiple source organs following exponential effective clearance of the radionuclide. A BED-based approach to determine the largest safe dose to critical organs has also been developed. The extended BED formalism is applied to red marrow dosimetry, as well as kidney dosimetry considering the cortex and the medulla separately, since both those organs are commonly dose limiting in radionuclide therapy. The analysis shows that because the red marrow is an early responding tissue (high {alpha}/{beta}), it is less susceptible to unexpected toxicity arising from rapid clearance of high levels of administered activity in the marrow or in the remainder of the body. In kidney dosimetry, the study demonstrates a complex interplay between clearance of activity in the cortex and the medulla, as well as the

  9. The radiation dosimetry of intrathecally administered radionuclides

    SciTech Connect

    Stabin, M.G.; Evans, J.F.

    1999-01-01

    The radiation dose to the spine, spinal cord, marrow, and other organs of the body from intrathecal administration of several radiopharmaceuticals was studied. Anatomic models were developed for the spine, spinal cerebrospinal fluid (CSF), spinal cord, spinal skeleton, cranial skeleton, and cranial CSF. A kinetic model for the transport of CSF was used to determine residence times in the CSF; material leaving the CSF was thereafter assumed to enter the bloodstream and follow the kinetics of the radiopharmaceutical as if intravenously administered. The radiation transport codes MCNP and ALGAMP were used to model the electron and photon transport and energy deposition. The dosimetry of Tc-99m DTPA and HSA, In-111 DTPA, I-131 HSA, and Yb-169 DTPA was studied. Radiation dose profiles for the spinal cord and marrow in the spine were developed and average doses to all other organs were estimated, including dose distributions within the bone and marrow.

  10. Thin film tritium dosimetry

    DOEpatents

    Moran, Paul R.

    1976-01-01

    The present invention provides a method for tritium dosimetry. A dosimeter comprising a thin film of a material having relatively sensitive RITAC-RITAP dosimetry properties is exposed to radiation from tritium, and after the dosimeter has been removed from the source of the radiation, the low energy electron dose deposited in the thin film is determined by radiation-induced, thermally-activated polarization dosimetry techniques.

  11. Chemical dosimetry system for criticality accidents.

    PubMed

    Miljanić, Saveta; Ilijas, Boris

    2004-01-01

    Ruder Bosković Institute (RBI) criticality dosimetry system consists of a chemical dosimetry system for measuring the total (neutron + gamma) dose, and a thermoluminescent (TL) dosimetry system for a separate determination of the gamma ray component. The use of the chemical dosemeter solution chlorobenzene-ethanol-trimethylpentane (CET) is based on the radiolytic formation of hydrochloric acid, which protonates a pH indicator, thymolsulphonphthalein. The high molar absorptivity of its red form at 552 nm is responsible for a high sensitivity of the system: doses in the range 0.2-15 Gy can be measured. The dosemeter has been designed as a glass ampoule filled with the CET solution and inserted into a pen-shaped plastic holder. For dose determinations, a newly constructed optoelectronic reader has been used. The RBI team took part in the International Intercomparison of Criticality Accident Dosimetry Systems at the SILENE Reactor, Valduc, June 2002, with the CET dosimetry system. For gamma ray dose determination TLD-700 TL detectors were used. The results obtained with CET dosemeter show very good agreement with the reference values.

  12. Bone marrow transplant

    MedlinePlus

    Transplant - bone marrow; Stem cell transplant; Hematopoietic stem cell transplant; Reduced intensity nonmyeloablative transplant; Mini transplant; Allogenic bone marrow transplant; Autologous bone marrow transplant; ...

  13. REVIEW OF DOSIMETRY FIELD

    DTIC Science & Technology

    three, oxalic acid , polyisobutylene, and Mylar film, seem sufficiently promising to warrant further development. Their current states of development...ceric sulfate dosimeters be included in the dosimetry handbook, but that additional work should be done on oxalic acid , polyisobutylene, and Mylar as dosimetry materials. (Author)

  14. Internal dosimetry - a review.

    SciTech Connect

    Potter, Charles Augustus

    2004-06-01

    The field history and current status of internal dosimetry is reviewed in this article. Elements of the field that are reviewed include standards and models, derivation of dose coefficients and intake retention fractions, bioassay measurements, and intake and dose calculations. In addition, guidance is developed and provided as to the necessity of internal dosimetry for a particular facility or operation and methodology for implementing a program. A discussion of the purposes of internal dosimetry is included as well as recommendations for future development and direction.

  15. Skeletal dosimetry in a voxel-based rat phantom for internal exposures to photons and electrons

    SciTech Connect

    Xie Tianwu; Han Dao; Liu Yang; Sun Wenjuan; Liu Qian

    2010-05-15

    Purpose: The skeleton makes a significant contribution to the whole body absorbed dose evaluation of rats, since the bone marrow and bone surface in the skeleton express high radiosensitivity and are considered to be important dose-limiting tissues. The bone marrow can be categorized as red bone marrow (RBM) and yellow bone marrow (YBM). It is important to investigate the bone marrow in skeletal dosimetry. Methods: Cryosectional color images of the skeleton of a 156 g rat were segmented into mineral bone (including cortical bone and trabecular bone), RBM, and YBM. These three tissue types were identified at 40 different bone sites and integrated into a previously developed voxel-based rat computational phantom. Photon and electron skeletal absorbed fractions were then calculated using the MCNPX Monte Carlo code. Results: Absorbed fraction (AF) and specific absorbed fraction (SAF) for mineral bone, RBM, and YBM at the 40 different bone sites were established for monoenergetic photon and electron sources placed in 18 organs and seven bone sites. Discrete photon energy was varied from 0.01 to 5.0 MeV in 21 discrete steps, while 21 discrete electron energies were studied, from 0.1 to 10.0 MeV. The trends and values found were consistent with the results of other researchers [M. G. Stabin, T. E. Peterson, G. E. Holburn, and M. A. Emmons, ''Voxel-based mouse and rat models for internal dose calculations,'' J. Nucl. Med. 47, 655-659 (2006)]. S-factors for the radionuclides {sup 169}Er, {sup 143}Pr, {sup 89}Sr, {sup 32}P, and {sup 90}Y, located in 18 organs and seven bone sites for the skeleton, were calculated and are provided in detail. Conclusions: For internal dose calculations, the AF data reveal that the mineral bone in the rat skeletal system is responsible for significant attenuation of gamma rays, especially at low energies. The photon SAF curves of RBM show that, for photon energies greater than 0.6 MeV, there is an increase in secondary photons emitted from the

  16. Personalized estimation of dose to red bone marrow and the associated leukaemia risk attributable to pelvic kilo-voltage cone beam computed tomography scans in image-guided radiotherapy

    NASA Astrophysics Data System (ADS)

    Zhang, Yibao; Yan, Yulong; Nath, Ravinder; Bao, Shanglian; Deng, Jun

    2012-07-01

    The aim of this study is to investigate the imaging dose to red bone marrow (RBM) and the associated leukaemia risks attributable to pelvic kilo-voltage cone beam computed tomography (kVCBCT) scans in image-guided radiation therapy (IGRT). The RBM doses of 42 patients (age 2.7-86.4 years) were calculated using Monte Carlo simulations. The trabecular spongiosa was segmented to substitute RBM rather than the whole bone. Quantitative correlations between anthropometric variables such as age, physical bone density (PBD) and RBM dose were established. Personalized leukaemia risk was evaluated using an improved Boice model which included the age-associated RBM involvement. An incremental leukaemia risk of 29%-82% (mean = 45%) was found to be associated with 40 pelvic kVCBCT scans in the subject group used in a typical external beam radiation therapy course. Higher risks were observed in children. Due to the enhanced photoelectric effect in high atomic number materials, PBD was observed to strongly affect the RBM dose. Considerable overestimations (9%-42%, mean = 28%) were observed if the whole bone doses were used as surrogates of RBM doses. The personalized estimation of RBM dose and associated leukaemia risk caused by pelvic kVCBCT scans is clinically feasible with the proposed empirical models. Higher radiogenic cancer risks are associated with repeated kVCBCT scans in IGRT of cancer patients, especially children.

  17. Bone marrow transplant - discharge

    MedlinePlus

    Transplant - bone marrow - discharge; Stem cell transplant - discharge; Hematopoietic stem cell transplant - discharge; Reduced intensity; Non-myeloablative transplant - discharge; Mini transplant - discharge; Allogenic bone marrow transplant - ...

  18. Ion storage dosimetry

    NASA Astrophysics Data System (ADS)

    Mathur, V. K.

    2001-09-01

    The availability of a reliable, accurate and cost-effective real-time personnel dosimetry system is fascinating to radiation workers. Electronic dosimeters are contemplated to meet this demand of active dosimetry. The development of direct ion storage (DIS) dosimeters, a member of the electronic dosimeter family, for personnel dosimetry is also an attempt in this direction. DIS dosimeter is a hybrid of the well-established technology of ion chambers and the latest advances in data storage using metal oxide semiconductor field effect transistor (MOSFET) analog memory device. This dosimeter is capable of monitoring legal occupational radiation doses of gamma, X-rays, beta and neutron radiation. Similar to an ion chamber, the performance of the dosimeter for a particular application can be optimized through the selection of appropriate wall materials. The use of the floating gate of a MOSFET as one of the electrodes of the ion chamber allows the miniaturization of the device to the size of a dosimetry badge and avoids the use of power supplies during dose accumulation. The concept of the device, underlying physics and the design of the DIS dosimeter are discussed. The results of preliminary testing of the device are also provided.

  19. Ion-kill dosimetry

    NASA Technical Reports Server (NTRS)

    Katz, R.; Cucinotta, F. A.; Fromm, M.; Chambaudet, A.

    2001-01-01

    Unanticipated late effects in neutron and heavy ion therapy, not attributable to overdose, imply a qualitative difference between low and high LET therapy. We identify that difference as 'ion kill', associated with the spectrum of z/beta in the radiation field, whose measurement we label 'ion-kill dosimetry'.

  20. The pathology of bone marrow failure.

    PubMed

    Leguit, Roos J; van den Tweel, Jan G

    2010-11-01

    An important indication for bone marrow investigation is the presence of bone marrow failure, which manifests itself as (pan)cytopenia. The causes of cytopenia are varied and differ considerably between childhood and adulthood. In the paediatric age group inherited bone marrow failure syndromes are important causes of bone marrow failure, but they play only a minor role in later life. This review gives a comprehensive overview of bone marrow failure disorders in children and adults. We classified the causes of bone marrow failure according to the main presenting haematological abnormality, i.e. anaemia, neutropenia, thrombocytopenia or pancytopenia. The following red cell disorders are discussed: red cell aplasia, sideroblastic anaemia, congenital dyserythropoietic anaemia, haemolytic anaemia, paroxysmal nocturnal haemoglobinuria, iron deficiency anaemia, anaemia of chronic disease and megaloblastic anaemia. The neutropenias occur in the context of Shwachman-Diamond syndrome (SDS), severe congenital neutropenia, cyclic neutropenia, immune-related neutropenia and non-immune neutropenia. In addition, the following causes of thrombocytopenia are discussed: congenital amegakaryocytic thrombocytopenia, thrombocytopenia with absent radii, immune-related thrombocytopenia and non-immune thrombocytopenia. Finally, we pay attention to the following pancytopenic disorders: Fanconi anaemia, dyskeratosis congenita, aplastic anaemia, myelodysplastic syndromes and human immunodeficiency virus (HIV) infection.

  1. In vivo dosimetry for IMRT

    SciTech Connect

    Vial, Philip

    2011-05-05

    In vivo dosimetry has a well established role in the quality assurance of 2D radiotherapy and 3D conformal radiotherapy. The role of in vivo dosimetry for IMRT is not as well established. IMRT introduces a range of technical issues that complicate in vivo dosimetry. The first decade or so of IMRT implementation has largely relied upon pre-treatment phantom based dose verification. During that time, several new devices and techniques for in vivo dosimetry have emerged with the promise of providing the ultimate form of IMRT dose verification. Solid state dosimeters continue to dominate the field of in vivo dosimetry in the IMRT era. In this report we review the literature on in vivo dosimetry for IMRT, with an emphasis on clinical evidence for different detector types. We describe the pros and cons of different detectors and techniques in the IMRT setting and the roles that they are likely to play in the future.

  2. Dosimetry for Radiopharmaceutical Therapy

    PubMed Central

    Sgouros, George; Hobbs, Robert F.

    2014-01-01

    Radiopharmaceutical therapy (RPT) involves the use of radionuclides that are either conjugated to tumor-targeting agents (eg, nanoscale constructs, antibodies, peptides, and small molecules) or concentrated in tissue through natural physiological mechanisms that occur predominantly in neoplastic or otherwise targeted cells (eg, Graves disease). The ability to collect pharmacokinetic data by imaging and use this to perform dosimetry calculations for treatment planning distinguishes RPT from other systemic treatment modalities. Treatment planning has not been widely adopted, in part, because early attempts to relate dosimetry to outcome were not successful. This was partially because a dosimetry methodology appropriate to risk evaluation rather than efficacy and toxicity was being applied to RPT. The weakest links in both diagnostic and therapeutic dosimetry are the accuracy of the input and the reliability of the radiobiological models used to convert dosimetric data to the relevant biologic end points. Dosimetry for RPT places a greater demand on both of these weak links. To date, most dosimetric studies have been retrospective, with a focus on tumor dose-response correlations rather than prospective treatment planning. In this regard, transarterial radioembolization also known as intra-arterial radiation therapy, which uses radiolabeled (90Y) microspheres of glass or resin to treat lesions in the liver holds much promise for more widespread dosimetric treatment planning. The recent interest in RPT with alpha-particle emitters has highlighted the need to adopt a dosimetry methodology that specifically accounts for the unique aspects of alpha particles. The short range of alpha-particle emitters means that in cases in which the distribution of activity is localized to specific functional components or cell types of an organ, the absorbed dose will be equally localized and dosimetric calculations on the scale of organs or even voxels (~5 mm) are no longer sufficient

  3. Electron Paramagnetic Resonance Retrospective Dosimetry

    SciTech Connect

    Romanyukha, Alex; Trompier, Francois

    2011-05-05

    Necessity for, principles of, and general concepts of the electron paramagnetic resonance (EPR) retrospective dosimetry are presented. Also presented and given in details are examples of EPR retrospective dosimetry applications in tooth enamel, bone, and fingernails with focus on general approaches for solving technical and methodological problems. Advantages, drawbacks, and possible future developments are discussed and an extensive bibliography on EPR retrospective dosimetry is provided.

  4. Photon and neutron fluence-to-kerma conversion factors for ICRP-1975 reference man using improved elemental compositions for bone and marrow of the skeleton

    SciTech Connect

    Kerr, G.D.

    1982-11-01

    A twelve-element approximation of the total-body, soft-tissue and skeletal components of ICRP-1975 Reference Man is used to investigate particle fluence-to-kerma conversion factors for photons with energies between 1 keV and 20 MeV and neutrons with energies between 0.0253 eV and 20 MeV. Several recent ICRP revisions to the elemental composition of Reference Man, which have not been included in other kerma-factor calculations, are taken into account. This work suggests some additional revisions to the major-element content (i.e., H, C, N, and O) and to the mineral and trace-element content (i.e., Na, Mg, P, S, Cl, K, Ca, and Fe) of various total-body, soft-tissue, and skeletal components of Reference Man. The revisions to the bone and red marrow of the skeleton offer significant new refinements in red-bone-marrow dosimetry.

  5. Skeletal dosimetry in the MAX06 and the FAX06 phantoms for external exposure to photons based on vertebral 3D-microCT images

    NASA Astrophysics Data System (ADS)

    Kramer, R.; Khoury, H. J.; Vieira, J. W.; Kawrakow, I.

    2006-12-01

    3D-microCT images of vertebral bodies from three different individuals have been segmented into trabecular bone, bone marrow and bone surface cells (BSC), and then introduced into the spongiosa voxels of the MAX06 and the FAX06 phantoms, in order to calculate the equivalent dose to the red bone marrow (RBM) and the BSC in the marrow cavities of trabecular bone with the EGSnrc Monte Carlo code from whole-body exposure to external photon radiation. The MAX06 and the FAX06 phantoms consist of about 150 million 1.2 mm cubic voxels each, a part of which are spongiosa voxels surrounded by cortical bone. In order to use the segmented 3D-microCT images for skeletal dosimetry, spongiosa voxels in the MAX06 and the FAX06 phantom were replaced at runtime by so-called micro matrices representing segmented trabecular bone, marrow and BSC in 17.65, 30 and 60 µm cubic voxels. The 3D-microCT image-based RBM and BSC equivalent doses for external exposure to photons presented here for the first time for complete human skeletons are in agreement with the results calculated with the three correction factor method and the fluence-to-dose response functions for the same phantoms taking into account the conceptual differences between the different methods. Additionally the microCT image-based results have been compared with corresponding data from earlier studies for other human phantoms. This article is dedicated to Prof. Dr Guenter Drexler from the Laboratório de Ciências Radiológicas, State University of Rio de Janeiro, on the occasion of his 70th birthday.

  6. Dosimetry of Radiopharmaceuticals for Diagnostic and Therapeutic Nuclear Medicine

    SciTech Connect

    Smart, Richard

    2011-05-05

    A standard formalism for radionuclide internal radiation dosimetry was developed in the 1960s and continues to be refined today. Early work was based on a mathematical phantom but this is being replaced by phantoms developed from whole-body CT scans to give more realistic dose estimates. The largest contributors to the uncertainties in these dose estimates are the errors associated with in vivo activity quantitation, the variability of the biokinetics between patients and the limited information that can be obtained on these kinetics in individual patients. Despite these limitations, pre-treatment patient-specific dosimetry is being increasing used, particularly to limit the toxicity to non-target organs such as the bone marrow.

  7. Dosimetry of Radiopharmaceuticals for Diagnostic and Therapeutic Nuclear Medicine

    NASA Astrophysics Data System (ADS)

    Smart, Richard

    2011-05-01

    A standard formalism for radionuclide internal radiation dosimetry was developed in the 1960s and continues to be refined today. Early work was based on a mathematical phantom but this is being replaced by phantoms developed from whole-body CT scans to give more realistic dose estimates. The largest contributors to the uncertainties in these dose estimates are the errors associated with in vivo activity quantitation, the variability of the biokinetics between patients and the limited information that can be obtained on these kinetics in individual patients. Despite these limitations, pre-treatment patient-specific dosimetry is being increasing used, particularly to limit the toxicity to non-target organs such as the bone marrow.

  8. Prostate PDT dosimetry

    PubMed Central

    Zhu, Timothy C.; Finlay, Jarod C.

    2015-01-01

    Summary We provide a review of the current state of dosimetry in prostate photodynamic therapy (PDT). PDT of the human prostate has been performed with a number of different photosensitizers and with a variety of dosimetry schemes. The simplest clinical light dose prescription is to quantify the total light energy emitted per length (J/cm) of cylindrical diffusing fibers (CDF) for patients treated with a defined photosensitizer injection per body weight. However, this approach does not take into account the light scattering by tissue and usually underestimates the local light fluence rate, and consequently the fluence. Techniques have been developed to characterize tissue optical properties and light fluence rates in vivo using interstitial measurements during prostate PDT. Optical methods have been developed to characterize tissue absorption and scattering spectra, which in turn provide information about tissue oxygenation and drug concentration. Fluorescence techniques can be used to quantify drug concentrations and photobleaching rates of photosensitizers. PMID:25046988

  9. Hanford External Dosimetry Program

    SciTech Connect

    Fix, J.J.

    1990-10-01

    This document describes the Hanford External Dosimetry Program as it is administered by Pacific Northwest Laboratory (PNL) in support of the US Department of Energy (DOE) and its Hanford contractors. Program services include administrating the Hanford personnel dosimeter processing program and ensuring that the related dosimeter data accurately reflect occupational dose received by Hanford personnel or visitors. Specific chapters of this report deal with the following subjects: personnel dosimetry organizations at Hanford and the associated DOE and contractor exposure guidelines; types, characteristics, and procurement of personnel dosimeters used at Hanford; personnel dosimeter identification, acceptance testing, accountability, and exchange; dosimeter processing and data recording practices; standard sources, calibration factors, and calibration processes (including algorithms) used for calibrating Hanford personnel dosimeters; system operating parameters required for assurance of dosimeter processing quality control; special dose evaluation methods applied for individuals under abnormal circumstances (i.e., lost results, etc.); and methods for evaluating personnel doses from nuclear accidents. 1 ref., 14 figs., 5 tabs.

  10. Neutron beam measurement dosimetry

    SciTech Connect

    Amaro, C.R.

    1995-11-01

    This report describes animal dosimetry studies and phantom measurements. During 1994, 12 dogs were irradiated at BMRR as part of a 4 fraction dose tolerance study. The animals were first infused with BSH and irradiated daily for 4 consecutive days. BNL irradiated 2 beagles as part of their dose tolerance study using BPA fructose. In addition, a dog at WSU was irradiated at BMRR after an infusion of BPA fructose. During 1994, the INEL BNCT dosimetry team measured neutron flux and gamma dose profiles in two phantoms exposed to the epithermal neutron beam at the BMRR. These measurements were performed as a preparatory step to the commencement of human clinical trials in progress at the BMRR.

  11. Structural features of bone marrow

    PubMed Central

    Romaniuk, Anatolii; Lyndina, Yuliia; Sikora, Vladyslav; Lyndin, Mykola; Karpenko, Ludmyla; Gladchenko, Oksana; Masalitin, Igor

    2016-01-01

    Purpose This article is devoted to the investigation of the structural features of the bone marrow of mature rats. Materials and methods The investigation of the structural features of the bone marrow was performed on the femurs of the mature male rats. General structure of the organ was studied with hematoxylin–eosin and Van Gieson staining of samples. Certain features of the bone marrow structure were studied using immunohistochemical method (CD3, CD79α, S100, myeloperoxidase, and cyclin D1). Results We can state that stromal–parenchymal structure is typical for the bone marrow of rats as for any other organ. The stromal component is presented with bone tissue (48.8 ± 3.3% at epiphyses), the net of blood vessels (18.7 ± 2.1%), fat tissue (11 ± 2%), fibrous tissue (0.7 ± 0.2%), and the network of reticular fibers. Hematopoietic tissue covers 20.9 ± 3.7% at the femoral epiphyses and 69.6 ± 2.2% at diaphysis. Among these tissues, myelopoiesis occupies 74.2 ± 4.7%, erythropoiesis – 24.3 ± 4.7%, and lymphopoiesis – less than 5%. Megalokaryocytes take 0.1–0.3%. Conclusion Considering the lack of significant anatomical, morphological, and histological differences of red bone marrow of rats and humans, we can state that hematopoiesis in rats takes place on the basis of the same principles as in humans, although it has certain mechanisms. PMID:28203394

  12. Bone marrow culture

    MedlinePlus

    ... There may be some bleeding at the puncture site. More serious risks, such as serious bleeding or infection, are very rare. Alternative Names Culture - bone marrow Images Bone marrow aspiration References ...

  13. WE-E-BRE-01: An Image-Based Skeletal Dosimetry Model for the ICRP Reference Adult Female - Internal Electron Sources

    SciTech Connect

    O'Reilly, S; Maynard, M; Marshall, E; Bolch, W; Sinclair, L; Rajon, D; Wayson, M

    2014-06-15

    Purpose: Limitations seen in previous skeletal dosimetry models, which are still employed in commonly used software today, include the lack of consideration of electron escape and cross-fire from cortical bone, the modeling of infinite spongiosa, the disregard of the effect of varying cellularity on active marrow self-irradiation, and the lack of use of the more recent ICRP definition of a 50 micron surrogate tissue region for the osteoprogenitor cells - shallow marrow. These limitations were addressed in the present dosimetry model. Methods: Electron transport was completed to determine specific absorbed fractions to active marrow and shallow marrow of the skeletal regions of the adult female. The bone macrostructure was obtained from the whole-body hybrid computational phantom of the UF series of reference phantoms, while the bone microstructure was derived from microCT images of skeletal region samples taken from a 45 year-old female cadaver. The target tissue regions were active marrow and shallow marrow. The source tissues were active marrow, inactive marrow, trabecular bone volume, trabecular bone surfaces, cortical bone volume and cortical bone surfaces. The marrow cellularity was varied from 10 to 100 percent for active marrow self-irradiation. A total of 33 discrete electron energies, ranging from 1 keV to 10 MeV, were either simulated or modeled analytically. Results: The method of combining macro- and microstructure absorbed fractions calculated using MCNPX electron transport was found to yield results similar to those determined with the PIRT model for the UF adult male in the Hough et al. study. Conclusion: The calculated skeletal averaged absorbed fractions for each source-target combination were found to follow similar trends of more recent dosimetry models (image-based models) and did not follow current models used in nuclear medicine dosimetry at high energies (due to that models use of an infinite expanse of trabecular spongiosa)

  14. Photostimulable Storage Phosphor Dosimetry

    NASA Astrophysics Data System (ADS)

    Frye, Douglas Mahaffey Danks

    The feasibility of employing alkaline earth sulfide based photostimulable storage phosphors for relative dosimetry in radiation oncology has been investigated. The dosimetric characteristics, radiologic characteristics, and spacial sensitivity of calcium sulfide and strontium sulfide based phosphors were determined. Dosimetric characteristics were explored by cavity theory calculation, Monte Carlo simulation, and physical measurement. Dosimetric characteristics obtained with cavity theory and Monte Carlo simulations agree well. The dose perturbation of the phosphor base materials were comparable to those produced by clinical dosimeter materials over the energy region employed in radiation oncology. Dose perturbation in regions downstream of the phosphor were measured with a variety of clinical dosimeters and compared with simulation results. The results of the measurements and simulations agreed within the uncertainty levels of the simulations and the measurements. Radiological characteristics of sensitivity, fading, dose response, dose rate response, and energy dependence of response were studied with an experimental phosphor output reader. Relative sensitivity was found to be dependent upon the mass thickness of phosphor layer. Fading was quantified for the calcium sulfide phosphor, with a half time of 2300 minutes. The strontium sulfide sample exhibited some fading, however, the regression lines yielded low correlation coefficients. A linear dose response over the range of doses employed in radiation oncology was obtained for both phosphors. No significant dose rate dependence of response was measured for the phosphors. The phosphor's energy dependence of response paralleled the dose perturbation relative to water predicted by cavity theory and simulations. Spatial sensitivity was demonstrated with an experimental phosphor scanner. The phosphors exhibited spatial sensitivity, however, infrared scattering/piping in the transparent substrate appeared to cause

  15. A study of predicted bone marrow distribution on calculated marrow dose from external radiation exposures using two sets of image data for the same individual.

    PubMed

    Caracappa, Peter F; Chao, T C Ephraim; Xu, X George

    2009-06-01

    Red bone marrow is among the tissues of the human body that are most sensitive to ionizing radiation, but red bone marrow cannot be distinguished from yellow bone marrow by normal radiographic means. When using a computational model of the body constructed from computed tomography (CT) images for radiation dose, assumptions must be applied to calculate the dose to the red bone marrow. This paper presents an analysis of two methods of calculating red bone marrow distribution: 1) a homogeneous mixture of red and yellow bone marrow throughout the skeleton, and 2) International Commission on Radiological Protection cellularity factors applied to each bone segment. A computational dose model was constructed from the CT image set of the Visible Human Project and compared to the VIP-Man model, which was derived from color photographs of the same individual. These two data sets for the same individual provide the unique opportunity to compare the methods applied to the CT-based model against the observed distribution of red bone marrow for that individual. The mass of red bone marrow in each bone segment was calculated using both methods. The effect of the different red bone marrow distributions was analyzed by calculating the red bone marrow dose using the EGS4 Monte Carlo code for parallel beams of monoenergetic photons over an energy range of 30 keV to 6 MeV, cylindrical (simplified CT) sources centered about the head and abdomen over an energy range of 30 keV to 1 MeV, and a whole-body electron irradiation treatment protocol for 3.9 MeV electrons. Applying the method with cellularity factors improves the average difference in the estimation of mass in each bone segment as compared to the mass in VIP-Man by 45% over the homogenous mixture method. Red bone marrow doses calculated by the two methods are similar for parallel photon beams at high energy (above about 200 keV), but differ by as much as 40% at lower energies. The calculated red bone marrow doses differ

  16. Uranium Dispersion & Dosimetry Model.

    SciTech Connect

    MICHAEL,; MOMENI, H.

    2002-03-22

    The Uranium Dispersion and Dosimetry (UDAD) program provides estimates of potential radiation exposure to individuals and to the general population in the vicinity of a uranium processing facility such as a uranium mine or mill. Only transport through the air is considered. Exposure results from inhalation, external irradiation from airborne and ground-deposited activity, and ingestion of foodstuffs. Individual dose commitments, population dose commitments, and environmental dose commitments are computed. The program was developed for application to uranium mining and milling; however, it may be applied to dispersion of any other pollutant.

  17. Fast neutron dosimetry

    SciTech Connect

    DeLuca, P.M. Jr.; Pearson, D.W.

    1992-01-01

    This progress report concentrates on two major areas of dosimetry research: measurement of fast neutron kerma factors for several elements for monochromatic and white spectrum neutron fields and determination of the response of thermoluminescent phosphors to various ultra-soft X-ray energies and beta-rays. Dr. Zhixin Zhou from the Shanghai Institute of Radiation Medicine, People's Republic of China brought with him special expertise in the fabrication and use of ultra-thin TLD materials. Such materials are not available in the USA. The rather unique properties of these materials were investigated during this grant period.

  18. Heavy-ion dosimetry

    SciTech Connect

    Schimmerling, W.

    1980-03-01

    This lecture deals with some of the more important physical characteristics of relativistic heavy ions and their measurement, with beam delivery and beam monitoring, and with conventional radiation dosimetry as used in the operation of the BEVALAC biomedical facility for high energy heavy ions (Lyman and Howard, 1977; BEVALAC, 1977). Even so, many fundamental aspects of the interaction of relativistic heavy ions with matter, including important atomic physics and radiation chemical considerations, are not discussed beyond the reminder that such additional understanding is required before an adequte perspective of the problem can be attained.

  19. Instrumental carbon monoxide dosimetry.

    PubMed

    Stetter, J R; Rutt, D R

    1980-10-01

    Modern technology for the ambient monitoring of carbon monoxide has been developed to produce a portable electrochemical instrument capable of the personal exposure to carbon monoxide. The performance characteristics of this device have been studied so that the unambiguous interpretation of field data could be performed. A study of the carbon monoxide exposure in a light manufacturing facility illustrate that effective dosimetry can be performed with expectations of accuracy typically better than +/- 15%, and that voluntary carbon monoxide exposures such as smoking were a significant contribution to the individual's exposure. Significant definition of the carbon monoxide exposure profile can be achieved with an instrument approach to the collection of the dosimetric data.

  20. Electron dosimetry for 10-MEV linac

    NASA Astrophysics Data System (ADS)

    Mehta, K. K.; Chu, R.; VanDyk, G.

    Recent developments in electron accelerator technology may allow the role of high-energy machines to expand. Implementation of appropriate dosimetry and quality comtrol methods for non-homogeneous materials is an important part of the expansion of this technology. To implement such methods and provide electron dosimetry for an applications development program, we recently conducted several dosimetry experiments. Our 10-MeV prototype electron accelerator as well as the accelerator at the National Research Council of Canada were used for these experiments. Polystyrene and graphite phantoms were constructed to measure the dose profile with depth. This yielded the extrapolated range and hence the most probable energy of the electrons in the beam. A polymethyl methacrylate (PMMA) sandwich-type range finder was also designed and used to directly measure the range and therefore the electron energy. Some of the range-finder results indicated that the charge buildup in the non- conducting PMMA affected the dose distribution. The measured energy values agreed very well with the beam energy values calculated from the analyzing magnet current of the accelerator. Also, responses of a graphite calorimeter as well as of various dosimeters compared fairly well in an electron field. The interface effects near the surface of homogeneous products were studied by analyzing the transmitted dose measured by the red acrylic continuous dosimeter placed under the products. The same technique was also used to examine the nature of inhomogeneity of various food products. We found this dosimeter extremely convenient and useful for measuring dose distribution in a plane. A Monte Carlo computer code was used to compute the depth-dose distributions in various materials and to compute the dose distribution near the interface of acrylic and air. These results were then compared against the measured distributions.

  1. Topical Review: Polymer gel dosimetry

    PubMed Central

    Baldock, C; De Deene, Y; Doran, S; Ibbott, G; Jirasek, A; Lepage, M; McAuley, K B; Oldham, M; Schreiner, L J

    2010-01-01

    Polymer gel dosimeters are fabricated from radiation sensitive chemicals which, upon irradiation, polymerize as a function of the absorbed radiation dose. These gel dosimeters, with the capacity to uniquely record the radiation dose distribution in three-dimensions (3D), have specific advantages when compared to one-dimensional dosimeters, such as ion chambers, and two-dimensional dosimeters, such as film. These advantages are particularly significant in dosimetry situations where steep dose gradients exist such as in intensity-modulated radiation therapy (IMRT) and stereotactic radiosurgery. Polymer gel dosimeters also have specific advantages for brachytherapy dosimetry. Potential dosimetry applications include those for low-energy x-rays, high-linear energy transfer (LET) and proton therapy, radionuclide and boron capture neutron therapy dosimetries. These 3D dosimeters are radiologically soft-tissue equivalent with properties that may be modified depending on the application. The 3D radiation dose distribution in polymer gel dosimeters may be imaged using magnetic resonance imaging (MRI), optical-computerized tomography (optical-CT), x-ray CT or ultrasound. The fundamental science underpinning polymer gel dosimetry is reviewed along with the various evaluation techniques. Clinical dosimetry applications of polymer gel dosimetry are also presented. PMID:20150687

  2. TOPICAL REVIEW: Polymer gel dosimetry

    NASA Astrophysics Data System (ADS)

    Baldock, C.; De Deene, Y.; Doran, S.; Ibbott, G.; Jirasek, A.; Lepage, M.; McAuley, K. B.; Oldham, M.; Schreiner, L. J.

    2010-03-01

    Polymer gel dosimeters are fabricated from radiation sensitive chemicals which, upon irradiation, polymerize as a function of the absorbed radiation dose. These gel dosimeters, with the capacity to uniquely record the radiation dose distribution in three-dimensions (3D), have specific advantages when compared to one-dimensional dosimeters, such as ion chambers, and two-dimensional dosimeters, such as film. These advantages are particularly significant in dosimetry situations where steep dose gradients exist such as in intensity-modulated radiation therapy (IMRT) and stereotactic radiosurgery. Polymer gel dosimeters also have specific advantages for brachytherapy dosimetry. Potential dosimetry applications include those for low-energy x-rays, high-linear energy transfer (LET) and proton therapy, radionuclide and boron capture neutron therapy dosimetries. These 3D dosimeters are radiologically soft-tissue equivalent with properties that may be modified depending on the application. The 3D radiation dose distribution in polymer gel dosimeters may be imaged using magnetic resonance imaging (MRI), optical-computerized tomography (optical-CT), x-ray CT or ultrasound. The fundamental science underpinning polymer gel dosimetry is reviewed along with the various evaluation techniques. Clinical dosimetry applications of polymer gel dosimetry are also presented.

  3. An image-based skeletal dosimetry model for the ICRP reference adult female—internal electron sources

    NASA Astrophysics Data System (ADS)

    O'Reilly, Shannon E.; DeWeese, Lindsay S.; Maynard, Matthew R.; Rajon, Didier A.; Wayson, Michael B.; Marshall, Emily L.; Bolch, Wesley E.

    2016-12-01

    An image-based skeletal dosimetry model for internal electron sources was created for the ICRP-defined reference adult female. Many previous skeletal dosimetry models, which are still employed in commonly used internal dosimetry software, do not properly account for electron escape from trabecular spongiosa, electron cross-fire from cortical bone, and the impact of marrow cellularity on active marrow self-irradiation. Furthermore, these existing models do not employ the current ICRP definition of a 50 µm bone endosteum (or shallow marrow). Each of these limitations was addressed in the present study. Electron transport was completed to determine specific absorbed fractions to both active and shallow marrow of the skeletal regions of the University of Florida reference adult female. The skeletal macrostructure and microstructure were modeled separately. The bone macrostructure was based on the whole-body hybrid computational phantom of the UF series of reference models, while the bone microstructure was derived from microCT images of skeletal region samples taken from a 45 years-old female cadaver. The active and shallow marrow are typically adopted as surrogate tissue regions for the hematopoietic stem cells and osteoprogenitor cells, respectively. Source tissues included active marrow, inactive marrow, trabecular bone volume, trabecular bone surfaces, cortical bone volume, and cortical bone surfaces. Marrow cellularity was varied from 10 to 100 percent for active marrow self-irradiation. All other sources were run at the defined ICRP Publication 70 cellularity for each bone site. A total of 33 discrete electron energies, ranging from 1 keV to 10 MeV, were either simulated or analytically modeled. The method of combining skeletal macrostructure and microstructure absorbed fractions assessed using MCNPX electron transport was found to yield results similar to those determined with the PIRT model applied to the UF adult male skeletal dosimetry model. Calculated

  4. An image-based skeletal dosimetry model for the ICRP reference adult female-internal electron sources.

    PubMed

    O'Reilly, Shannon E; DeWeese, Lindsay S; Maynard, Matthew R; Rajon, Didier A; Wayson, Michael B; Marshall, Emily L; Bolch, Wesley E

    2016-12-21

    An image-based skeletal dosimetry model for internal electron sources was created for the ICRP-defined reference adult female. Many previous skeletal dosimetry models, which are still employed in commonly used internal dosimetry software, do not properly account for electron escape from trabecular spongiosa, electron cross-fire from cortical bone, and the impact of marrow cellularity on active marrow self-irradiation. Furthermore, these existing models do not employ the current ICRP definition of a 50 µm bone endosteum (or shallow marrow). Each of these limitations was addressed in the present study. Electron transport was completed to determine specific absorbed fractions to both active and shallow marrow of the skeletal regions of the University of Florida reference adult female. The skeletal macrostructure and microstructure were modeled separately. The bone macrostructure was based on the whole-body hybrid computational phantom of the UF series of reference models, while the bone microstructure was derived from microCT images of skeletal region samples taken from a 45 years-old female cadaver. The active and shallow marrow are typically adopted as surrogate tissue regions for the hematopoietic stem cells and osteoprogenitor cells, respectively. Source tissues included active marrow, inactive marrow, trabecular bone volume, trabecular bone surfaces, cortical bone volume, and cortical bone surfaces. Marrow cellularity was varied from 10 to 100 percent for active marrow self-irradiation. All other sources were run at the defined ICRP Publication 70 cellularity for each bone site. A total of 33 discrete electron energies, ranging from 1 keV to 10 MeV, were either simulated or analytically modeled. The method of combining skeletal macrostructure and microstructure absorbed fractions assessed using MCNPX electron transport was found to yield results similar to those determined with the PIRT model applied to the UF adult male skeletal dosimetry model. Calculated

  5. The Utah Leukemia Case-Control Study: dosimetry methodology and results.

    PubMed

    Simon, S L; Till, J E; Lloyd, R D; Kerber, R L; Thomas, D C; Preston-Martin, S; Lyon, J L; Stevens, W

    1995-04-01

    This paper discusses the dosimetry methodology used to estimate bone marrow dose and the results of dosimetry calculations for 6,507 subjects in an epidemiologic case-control study of leukemia among Utah residents. The estimated doses were used to determine if a higher incidence of leukemia among residents of Utah could have been attributed to exposure to radioactive fallout from above-ground nuclear weapons tests conducted at the Nevada Test Site. The objective of the dosimetry methodology was to estimate absorbed dose to active marrow specific to each case and each control subject. Data on the residence of each subject were available from records of the Church of Jesus Christ of Latter-day Saints. Deposition of fallout was determined from databases developed using historical measurements and exposure for each subject from each test was estimated using those data. Exposure was converted to dose by applying an age-dependent dose conversion factor and a factor for shielding. The median dose for all case and control subjects was 3.2 mGy. The maximum estimated mean dose for any case or control was 29 +/- 5.6 mGy (a resident of Washington County, UT). Uncertainties were estimated for each estimated dose. The results of the dosimetry calculations were applied in an epidemiological analysis.

  6. The Utah leukemia case-control study: Dosimetry methodology and results

    SciTech Connect

    Simon, S.L.; Kerber, R.L.; Stevens, W.

    1995-04-01

    This paper discusses the dosimetry methodology used to estimate bone marrow dose and the results of dosimetry calculations for 6,507 subjects in an epidemiologic case. control study of leukemia among Utah residents. The estimated doses were used to determine if a higher incidence of leukemia among residents of Utah could have been attributed to exposure to radioactive fallout from above-ground nuclear weapons tests conducted at the Nevada Test Site. The objective of the dosimetry methodology was to estimate absorbed dose to active marrow specific to each case and each control subject. Data on the residence of each subject were available from records of the Church of Jesus Christ of Latter-day Saints. Deposition of fallout was determined from databases developed using historical measurements and exposure for each subject from each test was estimated using those data. Exposure was converted to dose by applying an age-dependent dose conversion factor and a factor for shielding. The median dose for all case and control subjects was 3.2 mGy. The maximum estimated mean dose for any case or control was 29 {plus_minus} 5.6 mGy (a resident of Washington County, UT). Uncertainties were estimated for each estimated dose. The results of the dosimetry calculations were applied in an epidemiological analysis.

  7. Internal dosimetry technical basis manual

    SciTech Connect

    Not Available

    1990-12-20

    The internal dosimetry program at the Savannah River Site (SRS) consists of radiation protection programs and activities used to detect and evaluate intakes of radioactive material by radiation workers. Examples of such programs are: air monitoring; surface contamination monitoring; personal contamination surveys; radiobioassay; and dose assessment. The objectives of the internal dosimetry program are to demonstrate that the workplace is under control and that workers are not being exposed to radioactive material, and to detect and assess inadvertent intakes in the workplace. The Savannah River Site Internal Dosimetry Technical Basis Manual (TBM) is intended to provide a technical and philosophical discussion of the radiobioassay and dose assessment aspects of the internal dosimetry program. Detailed information on air, surface, and personal contamination surveillance programs is not given in this manual except for how these programs interface with routine and special bioassay programs.

  8. Radioembolization Dosimetry: The Road Ahead

    SciTech Connect

    Smits, Maarten L. J. Elschot, Mattijs; Sze, Daniel Y.; Kao, Yung H.; Nijsen, Johannes F. W.; Iagaru, Andre H.; Jong, Hugo W. A. M. de; Bosch, Maurice A. A. J. van den; Lam, Marnix G. E. H.

    2015-04-15

    Methods for calculating the activity to be administered during yttrium-90 radioembolization (RE) are largely based on empirical toxicity and efficacy analyses, rather than dosimetry. At the same time, it is recognized that treatment planning based on proper dosimetry is of vital importance for the optimization of the results of RE. The heterogeneous and often clustered intrahepatic biodistribution of millions of point-source radioactive particles poses a challenge for dosimetry. Several studies found a relationship between absorbed doses and treatment outcome, with regard to both toxicity and efficacy. This should ultimately lead to improved patient selection and individualized treatment planning. New calculation methods and imaging techniques and a new generation of microspheres for image-guided RE will all contribute to these improvements. The aim of this review is to give insight into the latest and most important developments in RE dosimetry and to suggest future directions on patient selection, individualized treatment planning, and study designs.

  9. Radioembolization dosimetry: the road ahead.

    PubMed

    Smits, Maarten L J; Elschot, Mattijs; Sze, Daniel Y; Kao, Yung H; Nijsen, Johannes F W; Iagaru, Andre H; de Jong, Hugo W A M; van den Bosch, Maurice A A J; Lam, Marnix G E H

    2015-04-01

    Methods for calculating the activity to be administered during yttrium-90 radioembolization (RE) are largely based on empirical toxicity and efficacy analyses, rather than dosimetry. At the same time, it is recognized that treatment planning based on proper dosimetry is of vital importance for the optimization of the results of RE. The heterogeneous and often clustered intrahepatic biodistribution of millions of point-source radioactive particles poses a challenge for dosimetry. Several studies found a relationship between absorbed doses and treatment outcome, with regard to both toxicity and efficacy. This should ultimately lead to improved patient selection and individualized treatment planning. New calculation methods and imaging techniques and a new generation of microspheres for image-guided RE will all contribute to these improvements. The aim of this review is to give insight into the latest and most important developments in RE dosimetry and to suggest future directions on patient selection, individualized treatment planning, and study designs.

  10. Fifth international radiopharmaceutical dosimetry symposium

    SciTech Connect

    Watson, E.E.; Schlafke-Stelson, A.T.

    1992-05-01

    This meeting was held to exchange information on how to get better estimates of the radiation absorbed dose. There seems to be a high interest of late in patient dosimetry; discussions were held in the light of revised risk estimates for radiation. Topics included: Strategies of Dose Assessment; Dose Estimation for Radioimmunotherapy; Dose Calculation Techniques and Models; Dose Estimation for Positron Emission Tomography (PET); Kinetics for Dose Estimation; and Small Scale Dosimetry and Microdosimetry. (VC)

  11. The International Reactor Dosimetry File.

    SciTech Connect

    DUNFORD, CHARLIE

    2008-08-07

    Version 01 The International Reactor Dosimetry File (IRDF-2002) contains recommended neutron cross-section data to be used for reactor neutron dosimetry by foil activation and subsequent neutron spectrum unfolding. It also contains selected recom�mended values for radiation damage cross-sections and benchmark neutron spectra. Two related programs available from NEADB and RSICC are: SPECTER-ANL (PSR-263) & STAY’SL (PSR-113).

  12. Hanford internal dosimetry program manual

    SciTech Connect

    Carbaugh, E.H.; Sula, M.J.; Bihl, D.E.; Aldridge, T.L.

    1989-10-01

    This document describes the Hanford Internal Dosimetry program. Program Services include administrating the bioassay monitoring program, evaluating and documenting assessments of internal exposure and dose, ensuring that analytical laboratories conform to requirements, selecting and applying appropriate models and procedures for evaluating internal radionuclide deposition and the resulting dose, and technically guiding and supporting Hanford contractors in matters regarding internal dosimetry. 13 refs., 16 figs., 42 tabs.

  13. Dosimetry of iodoantipyrine.

    PubMed

    Chu, R Y; Ekeh, S; Basmadjian, G

    1989-01-01

    Dosimetry of iodoantipyrine labeled with radioactive iodine was determined by measuring the biodistribution of 131I-iodoantipyrine in 41 female rabbits. Following administration of the radiopharmaceutical, subjects were killed at 0.5, 6, 12, 17, 24, 36, and 48 h. Organs and samples of tissues and body fluids were assayed. Results were corrected for physical decay. Exponential functions were employed to describe the time-concentration curves; representative value would be the biological half life of 9.96 +/- 0.55 h for blood. Cumulated activity estimates for 123I, 125I and 131I were then computed. Extrapolation to absorbed dose in humans followed the formulation of the Medical International Radiation Dose (MIRD) Committee of the Society of Nuclear Medicine. The whole body absorbed doses are 7 mu Gray, 5 mu Gray and 29 mu Gray per MBq of 123I, 125I, and 131I administered respectively.

  14. Fundamentals of Radiation Dosimetry

    SciTech Connect

    Bos, Adrie J. J.

    2011-05-05

    The basic concepts of radiation dosimetry are reviewed on basis of ICRU reports and text books. The radiation field is described with, among others, the particle fluence. Cross sections for indirectly ionizing radiation are defined and indicated is how they are related to the mass energy transfer and mass energy absorption coefficients. Definitions of total and restricted mass stopping powers of directly ionizing radiation are given. The dosimetric quantities, kerma, absorbed dose and exposure together with the relations between them are discussed in depth. Finally it is indicated how the absorbed dose can be measured with a calorimeter by measuring the temperature increase and with an ionisation chamber measuring the charge produced by the ionizing radiation and making use of the Bragg-Gray relation.

  15. Fundamentals of Radiation Dosimetry

    NASA Astrophysics Data System (ADS)

    Bos, Adrie J. J.

    2011-05-01

    The basic concepts of radiation dosimetry are reviewed on basis of ICRU reports and text books. The radiation field is described with, among others, the particle fluence. Cross sections for indirectly ionizing radiation are defined and indicated is how they are related to the mass energy transfer and mass energy absorption coefficients. Definitions of total and restricted mass stopping powers of directly ionizing radiation are given. The dosimetric quantities, kerma, absorbed dose and exposure together with the relations between them are discussed in depth. Finally it is indicated how the absorbed dose can be measured with a calorimeter by measuring the temperature increase and with an ionisation chamber measuring the charge produced by the ionizing radiation and making use of the Bragg-Gray relation.

  16. Dosimetry considerations in phototherapy

    SciTech Connect

    Profio, A.E.; Doiron, D.R.

    1981-03-01

    Dosimetry in phototherapy involves a determination of the energy absorbed per unit mass of tissue, corrected for the quantum yield in a photochemical reaction. The dose rate in photochemotherapy of cancer with hematoporphyrin derivative and visible light is related to the extinction coefficient, quantum yield for singlet oxygen production, concentration of sensitizer and energy flux density at depth. Data or methods of determining these quantities are presented. Calculations have been performed for the energy flux density at depth, as a function of the total attenuation coefficient and ratio of scattering coefficient to total attenuation coefficient, for isotropic scattering in slab geometry. For small absorption, these depth dose curves exhibit a maximum within the tissue followed by an exponential decrease.

  17. Remote optical fiber dosimetry

    NASA Astrophysics Data System (ADS)

    Huston, A. L.; Justus, B. L.; Falkenstein, P. L.; Miller, R. W.; Ning, H.; Altemus, R.

    2001-09-01

    Optical fibers offer a unique capability for remote monitoring of radiation in difficult-to-access and/or hazardous locations. Optical fiber sensors can be located in radiation hazardous areas and optically interrogated from a safe distance. A variety of remote optical fiber radiation dosimetry methods have been developed. All of the methods take advantage of some form of radiation-induced change in the optical properties of materials such as: radiation-induced darkening due to defect formation in glasses, luminescence from native defects or radiation-induced defects, or population of metastable charge trapping centers. Optical attenuation techniques are used to measure radiation-induced darkening in fibers. Luminescence techniques include the direct measurement of scintillation or optical excitation of radiation-induced luminescent defects. Optical fiber radiation dosimeters have also been constructed using charge trapping materials that exhibit thermoluminescence or optically stimulated luminescence (OSL).

  18. Optimizing the dynamic range extension of a radiochromic film dosimetry system

    SciTech Connect

    Devic, Slobodan; Tomic, Nada; Soares, Christopher G.; Podgorsak, Ervin B.

    2009-02-15

    The authors present a radiochromic film dosimetry protocol for a multicolor channel radiochromic film dosimetry system consisting of the external beam therapy (EBT) model GAFCHROMIC film and the Epson Expression 1680 flat-bed document scanner. Instead of extracting only the red color channel, the authors are using all three color channels in the absorption spectrum of the EBT film to extend the dynamic dose range of the radiochromic film dosimetry system. By optimizing the dose range for each color channel, they obtained a system that has both precision and accuracy below 1.5%, and the optimized ranges are 0-4 Gy for the red channel, 4-50 Gy for the green channel, and above 50 Gy for the blue channel.

  19. Bone Marrow Diseases

    MedlinePlus

    Bone marrow is the spongy tissue inside some of your bones, such as your hip and thigh bones. It contains stem cells. The stem cells can ... the platelets that help with blood clotting. With bone marrow disease, there are problems with the stem ...

  20. Initial radiation dosimetry at Hiroshima and Nagasaki

    SciTech Connect

    Loewe, W.E.

    1983-09-01

    The dosimetry of A-bomb survivors at Hiroshima and Nagasaki is discussed in light of the new dosimetry developed in 1980 by the author. The important changes resulting from the new dosimetry are the ratios of neutron to gamma doses, particularly at Hiroshima. The implications of these changes in terms of epidemiology and radiation protection standards are discussed. (ACR)

  1. 4.2 Methods for Internal Dosimetry

    NASA Astrophysics Data System (ADS)

    Noßke, D.; Mattsson, S.; Johansson, L.

    This document is part of Subvolume A 'Fundamentals and Data in Radiobiology, Radiation Biophysics, Dosimetry and Medical Radiological Protection' of Volume 7 'Medical Radiological Physics' of Landolt-Börnstein - Group VIII 'Advanced Materials and Technologies'. It contains the Section '4.2 Methods for Internal Dosimetry' of the Chapter '4 Dosimetry in Nuclear Medicine Diagnosis and Therapy' with the contents:

  2. Nuclear accident dosimetry intercomparison studies.

    PubMed

    Sims, C S

    1989-09-01

    Twenty-two nuclear accident dosimetry intercomparison studies utilizing the fast-pulse Health Physics Research Reactor at the Oak Ridge National Laboratory have been conducted since 1965. These studies have provided a total of 62 different organizations a forum for discussion of criticality accident dosimetry, an opportunity to test their neutron and gamma-ray dosimetry systems under a variety of simulated criticality accident conditions, and the experience of comparing results with reference dose values as well as with the measured results obtained by others making measurements under identical conditions. Sixty-nine nuclear accidents (27 with unmoderated neutron energy spectra and 42 with eight different shielded spectra) have been simulated in the studies. Neutron doses were in the 0.2-8.5 Gy range and gamma doses in the 0.1-2.0 Gy range. A total of 2,289 dose measurements (1,311 neutron, 978 gamma) were made during the intercomparisons. The primary methods of neutron dosimetry were activation foils, thermoluminescent dosimeters, and blood sodium activation. The main methods of gamma dose measurement were thermoluminescent dosimeters, radiophotoluminescent glass, and film. About 68% of the neutron measurements met the accuracy guidelines (+/- 25%) and about 52% of the gamma measurements met the accuracy criterion (+/- 20%) for accident dosimetry.

  3. Studies in Ultrasonic Dosimetry.

    NASA Astrophysics Data System (ADS)

    Zitouni, Abderrachid

    The widespread use of ultrasonic devices in both industry and medicine confirms the great importance of ultrasound as a source of nonionizing radiation. The biological effects of this type of radiation are not completely known up to today, and the need for proper dosimetry is evident. Previous work in the field has been limited to the determination of ultrasonic energy deposition by attenuation measurements of traveling sound waves in homogenized specimens. Alternatively, observed effects were correlated to the output of the source. The objective of this work was to correlate the absorption properties of sound absorbing media to their elastic properties and deduce a correlation between the sonic absorption coefficient and the corresponding Young's modulus. Energy deposition measurements were performed in isotropic rubber samples and in anisotropic meat specimens by the use of the thermocouple probe method which measures the absorbed energy directly. Elasticity measurements were performed for the different types of materials used. The Young's modulus for each type was deduced from defletion measurements on rectangular strips when subjected to successive forces of varying magnitude. The final experimental results showed the existence of a linear relationship between the absorption coefficient of a given elastic material and the inverse square root of its Young's modulus.

  4. Bone marrow adipocytes as negative regulators of the hematopoietic microenvironment

    PubMed Central

    Naveiras, Olaia; Nardi, Valentina; Wenzel, Pamela L.; Fahey, Frederic; Daley, George Q.

    2009-01-01

    Osteoblasts and endothelium constitute functional niches that support hematopoietic stem cells (HSC) in mammalian bone marrow (BM) 1,2,3 . Adult BM also contains adipocytes, whose numbers correlate inversely with the hematopoietic activity of the marrow. Fatty infiltration of hematopoietic red marrow follows irradiation or chemotherapy and is a diagnostic feature in biopsies from patients with marrow aplasia 4. To explore whether adipocytes influence hematopoiesis or simply fill marrow space, we compared the hematopoietic activity of distinct regions of the mouse skeleton that differ in adiposity. By flow cytometry, colony forming activity, and competitive repopulation assay, HSCs and short-term progenitors are reduced in frequency in the adipocyte-rich vertebrae of the mouse tail relative to the adipocyte-free vertebrae of the thorax. In lipoatrophic A-ZIP/F1 “fatless” mice, which are genetically incapable of forming adipocytes8, and in mice treated with the PPARγ inhibitor Bisphenol-A-DiGlycidyl-Ether (BADGE), which inhibits adipogenesis9, post-irradiation marrow engraftment is accelerated relative to wild type or untreated mice. These data implicate adipocytes as predominantly negative regulators of the bone marrow microenvironment, and suggest that antagonizingmarrow adipogenesis may enhance hematopoietic recovery in clinical bone marrow transplantation. PMID:19516257

  5. Aspiration and Biopsy: Bone Marrow

    MedlinePlus

    ... Your 1- to 2-Year-Old Aspiration and Biopsy: Bone Marrow KidsHealth > For Parents > Aspiration and Biopsy: Bone Marrow A A A What's in this ... ósea What It Is Bone marrow aspirations and biopsies are performed to examine bone marrow, the spongy ...

  6. Aspiration and Biopsy: Bone Marrow

    MedlinePlus

    ... A Week of Healthy Breakfasts Shyness Aspiration and Biopsy: Bone Marrow KidsHealth > For Teens > Aspiration and Biopsy: Bone Marrow A A A What's in this ... Questions What It Is Bone marrow aspirations and biopsies are performed to examine bone marrow, the spongy ...

  7. Bone marrow biopsy

    MedlinePlus

    ... myelodysplastic syndrome; MDS) A nerve tissue tumor called neuroblastoma Bone marrow disease that leads to an abnormal ... Hairy cell leukemia Hodgkin lymphoma Multiple myeloma Myelofibrosis Neuroblastoma Non-Hodgkin lymphoma Platelet count Polycythemia vera Primary ...

  8. Marrow transplantation for leukemia

    SciTech Connect

    Thomas, E.D.

    1981-07-01

    Marrow transplantation for selected patients with leukemia, as for patients with severe combined immunologic deficiency or severe aplastic anemia, has now become an accepted clinical procedure. For patients with acute leukemia who have relapsed after achieving a remission of chemotherapy, marrow grafting from an identical twin or an HLA-identical sibling has now been demonstrated to produce median remissions as long as or longer than any reported for combination chemotherapy. In contrast to chemotherapy, marrow transplantation offers the possibility of cure for a small but significant fraction of these patients. Marrow transplantation for patients with ANL in first remission has now resulted in median survivals much longer than any reported with chemotherapy. Although it now appears that more than 50% of these patients can be cured with marrow transplantation, a much longer follow-up is indicated since some patients who achieve a complete remission with combination chemotherapy are now living for a long time, and some of these patients (less than 20%) may also be cured. Current intensive research with new modalities such as interferon, Acyclovir, Cyclosporin A, and monoclonal antibodies can reasonably be expected to improve the overall results of marrow transplantation.

  9. Plutonium worker dosimetry.

    PubMed

    Birchall, Alan; Puncher, M; Harrison, J; Riddell, A; Bailey, M R; Khokryakov, V; Romanov, S

    2010-05-01

    Epidemiological studies of the relationship between risk and internal exposure to plutonium are clearly reliant on the dose estimates used. The International Commission on Radiological Protection (ICRP) is currently reviewing the latest scientific information available on biokinetic models and dosimetry, and it is likely that a number of changes to the existing models will be recommended. The effect of certain changes, particularly to the ICRP model of the respiratory tract, has been investigated for inhaled forms of (239)Pu and uncertainties have also been assessed. Notable effects of possible changes to respiratory tract model assumptions are (1) a reduction in the absorbed dose to target cells in the airways, if changes under consideration are made to the slow clearing fraction and (2) a doubling of absorbed dose to the alveolar region for insoluble forms, if evidence of longer retention times is taken into account. An important factor influencing doses for moderately soluble forms of (239)Pu is the extent of binding of dissolved plutonium to lung tissues and assumptions regarding the extent of binding in the airways. Uncertainty analyses have been performed with prior distributions chosen for application in epidemiological studies. The resulting distributions for dose per unit intake were lognormal with geometric standard deviations of 2.3 and 2.6 for nitrates and oxides, respectively. The wide ranges were due largely to consideration of results for a range of experimental data for the solubility of different forms of nitrate and oxides. The medians of these distributions were a factor of three times higher than calculated using current default ICRP parameter values. For nitrates, this was due to the assumption of a bound fraction, and for oxides due mainly to the assumption of slower alveolar clearance. This study highlights areas where more research is needed to reduce biokinetic uncertainties, including more accurate determination of particle transport rates

  10. A probabilistic gastrointestinal tract dosimetry model

    NASA Astrophysics Data System (ADS)

    Huh, Chulhaeng

    In internal dosimetry, the tissues of the gastrointestinal (GI) tract represent one of the most radiosensitive organs of the body with the hematopoietic bone marrow. Endoscopic ultrasound is a unique tool to acquire in-vivo data on GI tract wall thicknesses of sufficient resolution needed in radiation dosimetry studies. Through their different echo texture and intensity, five layers of differing echo patterns for superficial mucosa, deep mucosa, submucosa, muscularis propria and serosa exist within the walls of organs composing the alimentary tract. Thicknesses for stomach mucosa ranged from 620 +/- 150 mum to 1320 +/- 80 mum (total stomach wall thicknesses from 2.56 +/- 0.12 to 4.12 +/- 0.11 mm). Measurements made for the rectal images revealed rectal mucosal thicknesses from 150 +/- 90 mum to 670 +/- 110 mum (total rectal wall thicknesses from 2.01 +/- 0.06 to 3.35 +/- 0.46 mm). The mucosa thus accounted for 28 +/- 3% and 16 +/- 6% of the total thickness of the stomach and rectal wall, respectively. Radiation transport simulations were then performed using the Monte Carlo N-particle transport code (MCNP) 4C transport code to calculate S values (Gy/Bq-s) for penetrating and nonpenetrating radiations such as photons, beta particles, conversion electrons and auger electrons of selected nuclides, I123, I131, Tc 99m and Y90 under two source conditions: content and mucosa sources, respectively. The results of this study demonstrate generally good agreement with published data for the stomach mucosa wall. The rectal mucosa data are consistently higher than published data compared with the large intestine due to different radiosensitive cell thicknesses (350 mum vs. a range spanning from 149 mum to 729 mum) and different geometry when a rectal content source is considered. Generally, the ICRP models have been designed to predict the amount of radiation dose in the human body from a "typical" or "reference" individual in a given population. The study has been performed to

  11. Unexplained overexposures on physical dosimetry reported by biological dosimetry.

    PubMed

    Montoro, A; Almonacid, M; Villaescusa, J I; Verdu, G

    2009-01-01

    The Medical Service of the Radiation Protection Service from the University Hospital La Fe (Valencia, Spain), carries out medical examinations of the workers occupationally exposed to ionising radiation. The Biological Dosimetry Laboratory is developing its activity since 2001. Up to now, the activities have been focused in performing biological dosimetry studies of Interventionists workers from La Fe Hospital. Recently, the Laboratory has been authorized by the Health Authority in the Valencian Community. Unexplained overexposures of workers and patients are also studied. Workers suspected of being overexposed to ionising radiation were referred for investigation by cytogenetic analysis. Two of these were from Hospitals of the Valencian Community and one belonged to an uranium mine from Portugal. Hospital workers had a physical dose by thermoluminiscence dosimeters (TLD) that exceeded the established limit. The worker of the uranium mine received a dose from a lost source of Cesium 137 with an activity of 170 mCi. All three cases showed normal values after the hematological analysis. Finally, the aim of this study consist to determine whether the dose showed by the dosimeter is reliable or not. In the case of workers that wore dosimeter, it is concluded that the doses measured by dosimeter are not corresponding to real doses. Hospital worker with a physical dose of 2.6 Sv and 0.269 Sv had an estimated absorbed dose by biological dosimetry of 0.076 Gy (0-0.165 Gy) and 0 Gy (0-0.089 Gy), respectively. In case of the mine worker an estimated absorbed dose of 0.073 Gy (0-0.159 Gy) was obtained by biological dosimetry. In all cases we used the odds ratio to present the results due to a very low frequency of observed aberrations [1].

  12. Skeletal dosimetry for external exposures to photons based on {mu}CT images of spongiosa: Consideration of voxel resolution, cluster size, and medullary bone surfaces

    SciTech Connect

    Kramer, R.; Khoury, H. J.; Vieira, J. W.; Brown, K. A. Robson

    2009-11-15

    Skeletal dosimetry based on {mu}CT images of trabecular bone has recently been introduced to calculate the red bone marrow (RBM) and the bone surface cell (BSC) equivalent doses in human phantoms for external exposure to photons. In order to use the {mu}CT images for skeletal dosimetry, spongiosa voxels in the skeletons were replaced at run time by so-called micromatrices, which have exactly the size of a spongiosa voxel and contain segmented trabecular bone and marrow microvoxels. A cluster (=parallelepiped) of 2x2x2=8 micromatrices was used systematically and periodically throughout the spongiosa volume during the radiation transport calculation. Systematic means that when a particle leaves a spongiosa voxel to enter into a neighboring spongiosa voxel, then the next micromatrix in the cluster will be used. Periodical means that if the particle travels through more than two spongiosa voxels in a row, then the cluster will be repeated. Based on the bone samples available at the time, clusters of up to 3x3x3=27 micromatrices were studied. While for a given trabecular bone volume fraction the whole-body RBM equivalent dose showed converging results for cluster sizes between 8 and 27 micromatrices, this was not the case for the BSC equivalent dose. The BSC equivalent dose seemed to be very sensitive to the number, form, and thickness of the trabeculae. In addition, the cluster size and/or the microvoxel resolution were considered to be possible causes for the differences observed. In order to resolve this problem, this study used a bone sample large enough to extract clusters containing up to 8x8x8=512 micromatrices and which was scanned with two different voxel resolutions. Taking into account a recent proposal, this investigation also calculated the BSC equivalent dose on medullary surfaces of cortical bone in the arm and leg bones. The results showed (1) that different voxel resolutions have no effect on the RBM equivalent dose but do influence the BSC equivalent

  13. Results from 2010 Caliban Criticality Dosimetry Intercomparison

    SciTech Connect

    Veinot, K. G.

    2011-10-12

    The external dosimetry program participated in a criticality dosimetry intercomparison conducted at the Caliban facility in Valduc, France in 2010. Representatives from the dosimetry and instrumentation groups were present during testing which included irradiations of whole-body beta/gamma (HBGT) and neutron thermoluminescent dosimeters (TLDs), a fixed nuclear accident dosimeter (FNAD), electronic alarming dosimeters, and a humanoid phantom filled with reference man concentrations of sodium. This report reviews the testing procedures, preparations, irradiations, and presents results of the tests.

  14. Bone-marrow transplant - slideshow

    MedlinePlus

    ... this page: //medlineplus.gov/ency/presentations/100112.htm Bone-marrow transplant - series—Normal anatomy To use the sharing ... Go to slide 4 out of 4 Overview Bone-marrow is a soft, fatty tissue found inside of ...

  15. How flatbed scanners upset accurate film dosimetry

    NASA Astrophysics Data System (ADS)

    van Battum, L. J.; Huizenga, H.; Verdaasdonk, R. M.; Heukelom, S.

    2016-01-01

    Film is an excellent dosimeter for verification of dose distributions due to its high spatial resolution. Irradiated film can be digitized with low-cost, transmission, flatbed scanners. However, a disadvantage is their lateral scan effect (LSE): a scanner readout change over its lateral scan axis. Although anisotropic light scattering was presented as the origin of the LSE, this paper presents an alternative cause. Hereto, LSE for two flatbed scanners (Epson 1680 Expression Pro and Epson 10000XL), and Gafchromic film (EBT, EBT2, EBT3) was investigated, focused on three effects: cross talk, optical path length and polarization. Cross talk was examined using triangular sheets of various optical densities. The optical path length effect was studied using absorptive and reflective neutral density filters with well-defined optical characteristics (OD range 0.2-2.0). Linear polarizer sheets were used to investigate light polarization on the CCD signal in absence and presence of (un)irradiated Gafchromic film. Film dose values ranged between 0.2 to 9 Gy, i.e. an optical density range between 0.25 to 1.1. Measurements were performed in the scanner’s transmission mode, with red-green-blue channels. LSE was found to depend on scanner construction and film type. Its magnitude depends on dose: for 9 Gy increasing up to 14% at maximum lateral position. Cross talk was only significant in high contrast regions, up to 2% for very small fields. The optical path length effect introduced by film on the scanner causes 3% for pixels in the extreme lateral position. Light polarization due to film and the scanner’s optical mirror system is the main contributor, different in magnitude for the red, green and blue channel. We concluded that any Gafchromic EBT type film scanned with a flatbed scanner will face these optical effects. Accurate dosimetry requires correction of LSE, therefore, determination of the LSE per color channel and dose delivered to the film.

  16. Dosimetry studies in Zaborie village.

    PubMed

    Takada, J; Hoshi, M; Endo, S; Stepanenko, V F; Kondrashov, A E; Petin, D; Skvortsov, V; Ivannikov, A; Tikounov, D; Gavrilin, Y; Snykov, V P

    2000-05-01

    Dosimetry studies in Zaborie, a territory in Russia highly contaminated by the Chernobyl accident, were carried out in July, 1997. Studies on dosimetry for people are important not only for epidemiology but also for recovery of local social activity. The local contamination of the soil was measured to be 1.5-6.3 MBq/m2 of Cs-137 with 0.7-4 microSv/h of dose rate. A case study for a villager presently 40 years old indicates estimations of 72 and 269 mSv as the expected internal and external doses during 50 years starting in 1997 based on data of a whole-body measurement of Cs-137 and environmental dose rates. Mean values of accumulated external and internal doses for the period from the year 1986 till 1996 are also estimated to be 130 mSv and 16 mSv for Zaborie. The estimation of the 1986-1996 accumulated dose on the basis of large scale ESR teeth enamel dosimetry provides for this village, the value of 180 mSv. For a short term visitor from Japan to this area, external and internal dose are estimated to be 0.13 mSv/9d (during visit in 1997) and 0.024 mSv/50y (during 50 years starting from 1997), respectively.

  17. I-124 Imaging and Dosimetry.

    PubMed

    Kuker, Russ; Sztejnberg, Manuel; Gulec, Seza

    2016-01-05

    Although radioactive iodine imaging and therapy are one of the earliest applications of theranostics, there still remain a number of unresolved clinical questions as to the optimization of diagnostic techniques and dosimetry protocols. I-124 as a positron emission tomography (PET) radiotracer has the potential to improve the current clinical practice in the diagnosis and treatment of differentiated thyroid cancer. The higher sensitivity and spatial resolution of PET/computed tomography (CT) compared to standard gamma scintigraphy can aid in the detection of recurrent or metastatic disease and provide more accurate measurements of metabolic tumor volumes. However the complex decay schema of I-124 poses challenges to quantitative PET imaging. More prospective studies are needed to define optimal dosimetry protocols and to improve patient-specific treatment planning strategies, taking into account not only the absorbed dose to tumors but also methods to avoid toxicity to normal organs. A historical perspective of I-124 imaging and dosimetry as well as future concepts are discussed.

  18. I-124 Imaging and Dosimetry

    PubMed Central

    Kuker, Russ; Sztejnberg, Manuel; Gulec, Seza

    2017-01-01

    Although radioactive iodine imaging and therapy are one of the earliest applications of theranostics, there still remain a number of unresolved clinical questions as to the optimization of diagnostic techniques and dosimetry protocols. I-124 as a positron emission tomography (PET) radiotracer has the potential to improve the current clinical practice in the diagnosis and treatment of differentiated thyroid cancer. The higher sensitivity and spatial resolution of PET/computed tomography (CT) compared to standard gamma scintigraphy can aid in the detection of recurrent or metastatic disease and provide more accurate measurements of metabolic tumor volumes. However the complex decay schema of I-124 poses challenges to quantitative PET imaging. More prospective studies are needed to define optimal dosimetry protocols and to improve patient-specific treatment planning strategies, taking into account not only the absorbed dose to tumors but also methods to avoid toxicity to normal organs. A historical perspective of I-124 imaging and dosimetry as well as future concepts are discussed. PMID:28117290

  19. Small fields: Nonequilibrium radiation dosimetry

    SciTech Connect

    Das, Indra J.; Ding, George X.; Ahnesjoe, Anders

    2008-01-15

    Advances in radiation treatment with beamlet-based intensity modulation, image-guided radiation therapy, and stereotactic radiosurgery (including specialized equipments like CyberKnife, Gamma Knife, tomotherapy, and high-resolution multileaf collimating systems) have resulted in the use of reduced treatment fields to a subcentimeter scale. Compared to the traditional radiotherapy with fields {>=}4x4 cm{sup 2}, this can result in significant uncertainty in the accuracy of clinical dosimetry. The dosimetry of small fields is challenging due to nonequilibrium conditions created as a consequence of the secondary electron track lengths and the source size projected through the collimating system that are comparable to the treatment field size. It is further complicated by the prolonged electron tracks in the presence of low-density inhomogeneities. Also, radiation detectors introduced into such fields usually perturb the level of disequilibrium. Hence, the dosimetric accuracy previously achieved for standard radiotherapy applications is at risk for both absolute and relative dose determination. This article summarizes the present knowledge and gives an insight into the future procedures to handle the nonequilibrium radiation dosimetry problems. It is anticipated that new miniature detectors with controlled perturbations and corrections will be available to meet the demand for accurate measurements. It is also expected that the Monte Carlo techniques will increasingly be used in assessing the accuracy, verification, and calculation of dose, and will aid perturbation calculations of detectors used in small and highly conformal radiation beams.

  20. Internal dosimetry for radioembolization therapy with Yttrium-90 microspheres.

    PubMed

    Fallahpoor, Maryam; Abbasi, Mehrshad; Parach, Ali Asghar; Kalantari, Faraz

    2017-03-01

    The absorbed doses in the liver and adjacent viscera in Yttrium-90 radioembolization therapy for metastatic liver lesions are not well-documented. We sought for a clinically practical way to determine the dosimetry of this advent treatment. Six different female XCAT BMIs and seven different male XCAT BMIs were generated. Using Monte Carlo GATE code simulation, the total of 100MBq (90) Y was deposited uniformly in the source organ, liver. Self-irradiation and absorbed doses in lung, kidney and bone marrow were calculated. The mean energy of Yittrium-90 (i.e., 0.937 MeV) was used. The S-values and equivalent doses in target organs were estimated. The dose absorbed in the liver was between 84 and 53 Gy and below the target of 80 to 150 Gy. The absorbed dose in the bone marrow, lungs, and kidneys are very low and below 0.1 , 0.4, and 0.5 Gy respectively. Our study indicates that larger activities than the conventional dose of 3 GBq may be both required and safe. Further confirmations in clinical settings are needed.

  1. Overview of marrow transplantation

    SciTech Connect

    Thomas, E.D.

    1985-12-01

    Bone marrow transplantation is now an accepted form of therapy for many hematologic disorders including aplastic anemia, genetically determined diseases and malignant diseases, particularly leukemia, and for rescue of patients given intensive chemoradiotherapy for malignant disease. The donor may be a healthy identical twin, a family member or even an unrelated person. Selection is made on the basis of human leukocyte antigen tissue typing. Intensive chemoradiotherapy is used to suppress patients' immune systems to facilitate engraftment and destroy diseased marrow. Transfusion of platelets, erythrocytes and granulocytes (or all of these), antibiotic coverage and protection from infection are necessary during the pancytopenic period. Survival rates vary considerably depending on a patient's disease, clinical state and age. Patients with aplastic anemia transplanted early in the course of their disease have a survival rate of approximately 80%. Patients with acute lymphoblastic leukemia are usually transplanted in a second or subsequent remission and have a survival rate of 25% to 40%. Patients with acute nonlymphoblastic leukemia in remission have survivals ranging from 45% to 70%. More than 200 patients in the chronic phase of chronic granulocytic leukemia have been transplanted with survival ranging from 50% to 70%. Complications of marrow transplantation include marrow graft rejection, graft-versus-host disease, immunologic insufficiency and the possibility of recurrence of the leukemia. 14 references.

  2. National Marrow Donor Program

    DTIC Science & Technology

    2011-04-29

    associated with improved outcomes following unrelated allogeneic stem cell transplantation for acute myeloid leukemia . Oral presentation 2011 BMT Tandem...appropriate emergency preparedness or response organization to inform about RITN. Educate: educate staff about radiation, acute radiation syndrome ...Development of Medical Technology for Contingency Response to Marrow Toxic Agents January 01, 2011 through March 31, 2011 18 of 21 acute GVHD after

  3. [Modified method for whole bone marrow adherent culture of human bone marrow mesenchymal stem cells].

    PubMed

    Wang, Xiao-Qing; Zhong, Zhao-Dong; Chen, Zhi-Chao; Zou, Ping

    2014-04-01

    This study was aimed to investigate a more convenient and efficient method to cultivate the human bone marrow mesenchymal stem cells by means of natural erythrocyte sedimentation principle, based on the whole bone marrow adherent method. The bone marrow was cultured with a six-well plate instead of the flasks.Firstly, the bone marrow specimen was cultivated with the MSC complete medium for 48 h, then the upper RBC-free supernatant layer was drawn and placed into the new wells to isolate MSC. Inverted microscope was used to observe the cell morphology and to record the adherent time of first cell passage, first passaging time. The traditional whole bone marrow adherent method was used as the control. The cell cycle and cell surface markers were detected by flow cytometry,and the differentiative capacity of MSC into osteocyte and adipocyte was identified by alkaline phosphatase kit and oil red O, respectively. Besides, the proliferative curve of P1,P3,P5 of BMSC was depicted by counting method. The results showed that MSC cultured by the modified method highly expressed CD90, CD105, CD13, CD44 and lowly expressed CD14, CD45, CD34. Concerning the cell cycle feature, it was found that most of the cells were in G0/G1 phase (88.76%) , followed by G2/M phase (3.04%) and S phase (8.2%), which was in accordance with stem cell cycle characteristics. The proliferative curve showed a typical "S" type, and both the oil red O and alkaline phosphatase staining of MSC were positive. Compared with the traditional method, the modified method had the advantage of high adherence rate (P = 0.0001) and shorter passaging time for the first passage (P = 0.001), with the statistically significant difference. It is concluded that there is a large number of adherent, active and suspended MSC in the RBC-free supernatant layer after the culture of bone marrow for 48 h. Isolating MSC by the modified method is more convenient and efficient than the traditional whole bone marrow adherent method.

  4. Gafchromic EBT2 film dosimetry in reflection mode with a novel plan-based calibration method

    SciTech Connect

    Mendez, I.; Hartman, V.; Hudej, R.; Strojnik, A.; Casar, B.

    2013-01-15

    Purpose:A dosimetric system formed by Gafchromic EBT2 radiochromic film and Epson Expression 10000XL flatbed scanner was commissioned for dosimetry. In this paper, several open questions concerning the commissioning of radiochromic films for dosimetry were addressed: (a) is it possible to employ this dosimetric system in reflection mode; (b) if so, can the methods used in transmission mode also be used in reflection mode; (c) is it possible to obtain accurate absolute dose measurements with Gafchromic EBT2 films; (d) which calibration method should be followed; (e) which calibration models should be used; and (f) does three-color channel dosimetry offer a significant improvement over single channel dosimetry. The purpose of this paper is to help clarify these questions. Methods: In this study, films were scanned in reflection mode, the effect of surrounding film was evaluated and the feasibility of EBT2 film dosimetry in reflection mode was studied. EBT2's response homogeneity has been reported to lead to excessive dose uncertainties. To overcome this problem, a new plan-based calibration method was implemented. Plan-based calibration can use every pixel and each of the three color channels of the scanned film to obtain the parameters of the calibration model. A model selection analysis was conducted to select lateral correction and sensitometric curve models. The commonly used calibration with fragments was compared with red-channel plan-based calibration and with three-channel plan-based calibration. Results: No effect of surrounding film was found in this study. The film response inhomogeneity in EBT2 films was found to be important not only due to differences in the fog but also due to differences in sensitivity. The best results for lateral corrections were obtained using absolute corrections independent of the dose. With respect to the sensitometric curves, an empirical polynomial fit of order 4 was found to obtain results equivalent to a gamma

  5. An image-based skeletal dosimetry model for the ICRP reference newborn--internal electron sources.

    PubMed

    Pafundi, Deanna; Rajon, Didier; Jokisch, Derek; Lee, Choonsik; Bolch, Wesley

    2010-04-07

    In this study, a comprehensive electron dosimetry model of newborn skeletal tissues is presented. The model is constructed using the University of Florida newborn hybrid phantom of Lee et al (2007 Phys. Med. Biol. 52 3309-33), the newborn skeletal tissue model of Pafundi et al (2009 Phys. Med. Biol. 54 4497-531) and the EGSnrc-based Paired Image Radiation Transport code of Shah et al (2005 J. Nucl. Med. 46 344-53). Target tissues include the active bone marrow (surrogate tissue for hematopoietic stem cells), shallow marrow (surrogate tissue for osteoprogenitor cells) and unossified cartilage (surrogate tissue for chondrocytes). Monoenergetic electron emissions are considered over the energy range 1 keV to 10 MeV for the following source tissues: active marrow, trabecular bone (surfaces and volumes), cortical bone (surfaces and volumes) and cartilage. Transport results are reported as specific absorbed fractions according to the MIRD schema and are given as skeletal-averaged values in the paper with bone-specific values reported in both tabular and graphic format as electronic annexes (supplementary data). The method utilized in this work uniquely includes (1) explicit accounting for the finite size and shape of newborn ossification centers (spongiosa regions), (2) explicit accounting for active and shallow marrow dose from electron emissions in cortical bone as well as sites of unossified cartilage, (3) proper accounting of the distribution of trabecular and cortical volumes and surfaces in the newborn skeleton when considering mineral bone sources and (4) explicit consideration of the marrow cellularity changes for active marrow self-irradiation as applicable to radionuclide therapy of diseased marrow in the newborn child.

  6. 10 CFR 35.630 - Dosimetry equipment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Dosimetry equipment. 35.630 Section 35.630 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Photon Emitting Remote Afterloader Units, Teletherapy Units, and Gamma Stereotactic Radiosurgery Units § 35.630 Dosimetry equipment. (a) Except for low...

  7. Red and NIR light dosimetry in the human deep brain

    NASA Astrophysics Data System (ADS)

    Pitzschke, A.; Lovisa, B.; Seydoux, O.; Zellweger, M.; Pfleiderer, M.; Tardy, Y.; Wagnières, G.

    2015-04-01

    Photobiomodulation (PBM) appears promising to treat the hallmarks of Parkinson’s Disease (PD) in cellular or animal models. We measured light propagation in different areas of PD-relevant deep brain tissue during transcranial, transsphenoidal illumination (at 671 and 808 nm) of a cadaver head and modeled optical parameters of human brain tissue using Monte-Carlo simulations. Gray matter, white matter, cerebrospinal fluid, ventricles, thalamus, pons, cerebellum and skull bone were processed into a mesh of the skull (158 × 201 × 211 voxels; voxel side length: 1 mm). Optical parameters were optimized from simulated and measured fluence rate distributions. The estimated μeff for the different tissues was in all cases larger at 671 than at 808 nm, making latter a better choice for light delivery in the deep brain. Absolute values were comparable to those found in the literature or slightly smaller. The effective attenuation in the ventricles was considerably larger than literature values. Optimization yields a new set of optical parameters better reproducing the experimental data. A combination of PBM via the sphenoid sinus and oral cavity could be beneficial. A 20-fold higher efficiency of light delivery to the deep brain was achieved with ventricular instead of transcranial illumination. Our study demonstrates that it is possible to illuminate deep brain tissues transcranially, transsphenoidally and via different application routes. This opens therapeutic options for sufferers of PD or other cerebral diseases necessitating light therapy.

  8. Solid-State Personal Dosimetry

    NASA Technical Reports Server (NTRS)

    Wrbanek, John D.; Fralick, Gustave C.; Wrbanek, Susan Y.

    2005-01-01

    This document is a web site page, and a data sheet about Personal protection (i.e., space suits) presented to the Radiation and Micrometeoroid Mitigation Technology Focus Group meeting. The website describes the work of the PI to improve solid state personal radiation dosimetry. The data sheet presents work on the active personal radiation detection system that is to provide real-time local radiation exposure information during EVA. Should undue exposure occur, knowledge of the dynamic intensity conditions during the exposure will allow more precise diagnostic assessment of the potential health risk to the exposed individual.

  9. The future of medical dosimetry.

    PubMed

    Adams, Robert D

    2015-01-01

    The world of health care delivery is becoming increasingly complex. The purpose of this manuscript is to analyze current metrics and analytically predict future practices and principles of medical dosimetry. The results indicate five potential areas precipitating change factors: a) evolutionary and revolutionary thinking processes, b) social factors, c) economic factors, d) political factors, and e) technological factors. Outcomes indicate that significant changes will occur in the job structure and content of being a practicing medical dosimetrist. Discussion indicates potential variables that can occur within each process and change factor and how the predicted outcomes can deviate from normative values. Finally, based on predicted outcomes, future opportunities for medical dosimetrists are given.

  10. The Future of Medical Dosimetry

    SciTech Connect

    Adams, Robert D.

    2015-07-01

    The world of health care delivery is becoming increasingly complex. The purpose of this manuscript is to analyze current metrics and analytically predict future practices and principles of medical dosimetry. The results indicate five potential areas precipitating change factors: a) evolutionary and revolutionary thinking processes, b) social factors, c) economic factors, d) political factors, and e) technological factors. Outcomes indicate that significant changes will occur in the job structure and content of being a practicing medical dosimetrist. Discussion indicates potential variables that can occur within each process and change factor and how the predicted outcomes can deviate from normative values. Finally, based on predicted outcomes, future opportunities for medical dosimetrists are given.

  11. Health physics research reactor reference dosimetry

    SciTech Connect

    Sims, C.S.; Ragan, G.E.

    1987-06-01

    Reference neutron dosimetry is developed for the Health Physics Research Reactor (HPRR) in the new operational configuration directly above its storage pit. This operational change was physically made early in CY 1985. The new reference dosimetry considered in this document is referred to as the 1986 HPRR reference dosimetry and it replaces any and all HPRR reference documents or papers issued prior to 1986. Reference dosimetry is developed for the unshielded HPRR as well as for the reactor with each of five different shield types and configurations. The reference dosimetry is presented in terms of three different dose and six different dose equivalent reporting conventions. These reporting conventions cover most of those in current use by dosimetrists worldwide. In addition to the reference neutron dosimetry, this document contains other useful dosimetry-related data for the HPRR in its new configuration. These data include dose-distance measurements and calculations, gamma dose measurements, neutron-to-gamma ratios, ''9-to-3 inch'' ratios, threshold detector unit measurements, 56-group neutron energy spectra, sulfur fluence measurements, and details concerning HPRR shields. 26 refs., 11 figs., 31 tabs.

  12. A Dosimetric Study of Radionuclide Therapy for Bone Marrow Ablation.

    NASA Astrophysics Data System (ADS)

    Bayouth, John Ellis

    In a phase I clinical trial, six multiple myeloma patients, who were non-responsive to conventional therapy and were scheduled for bone marrow transplantation, received Holmium-166 (166Ho) labeled to a bone seeking agent, DOTMP (1,4,7,10-tetraazacyclododecane -1,4,7,10-tetramethylene-phosphonic acid), for the purpose of bone marrow ablation. The specific aims of my research within this protocol were to evaluate the toxicity and efficacy of 166Ho DOTMP by quantifying the in vivo pharmacokinetics and radiation dosimetry, and by correlating these results to the biologic response observed. The reproducibility of pharmacokinetics from multiple injections of 166 Ho DOTMP administered to these myeloma patients was demonstrated from both blood and whole body retention. The skeletal concentration of 166 Ho DOTMP was heterogenous in all six patients: high in the ribs, pelvis, and lumbar vertebrae regions, and relatively low in the femurs, arms, and head. A novel technique was developed to calculate the radiation dose to the bone marrow in each skeletal ROI, and was applied to all six 166 Ho DOTMP patients. Radiation dose estimates for the bone marrow calculated using the standard MIRD "S" factors were compared with the average values derived from the heterogenous distribution of activity in the skeleton (i.e., the regional technique). The results from the two techniques were significantly different; the average of the dose estimates from the regional technique were typically 30% greater. Furthermore, the regional technique provided a range of radiation doses for the entire marrow volume, while the MIRD "S" factors only provided a single value. Dose volume histogram analysis of data from the regional technique indicated a range of dose estimates that varied by a factor of 10 between the high dose and low dose regions. Finally, the observed clinical response of cells and abnormal proteins measured in bone marrow aspirates and peripheral blood samples were compared with

  13. In vitro dosimetry of agglomerates

    NASA Astrophysics Data System (ADS)

    Hirsch, V.; Kinnear, C.; Rodriguez-Lorenzo, L.; Monnier, C. A.; Rothen-Rutishauser, B.; Balog, S.; Petri-Fink, A.

    2014-06-01

    Agglomeration of nanoparticles in biological fluids is a pervasive phenomenon that leads to difficulty in the interpretation of results from in vitro exposure, primarily due to differing particokinetics of agglomerates to nanoparticles. Therefore, well-defined small agglomerates were designed that possessed different particokinetic profiles, and their cellular uptake was compared to a computational model of dosimetry. The approach used here paves the way for a better understanding of the impact of agglomeration on the nanoparticle-cell interaction.Agglomeration of nanoparticles in biological fluids is a pervasive phenomenon that leads to difficulty in the interpretation of results from in vitro exposure, primarily due to differing particokinetics of agglomerates to nanoparticles. Therefore, well-defined small agglomerates were designed that possessed different particokinetic profiles, and their cellular uptake was compared to a computational model of dosimetry. The approach used here paves the way for a better understanding of the impact of agglomeration on the nanoparticle-cell interaction. Electronic supplementary information (ESI) available: ITC data for tiopronin/Au-NP interactions, agglomeration kinetics at different pHs for tiopronin-coated Au-NPs, UV-Vis spectra in water, PBS and DMEM and temporal correlation functions for single Au-NPs and corresponding agglomerates, calculation of diffusion and sedimentation parameters, modelling of relative cell uptake based on the ISDD model and cytotoxicity of single Au-NPs and their agglomerates, and synthesis and cell uptake of large spherical Au-NPs. See DOI: 10.1039/c4nr00460d

  14. An Automated Biological Dosimetry System

    NASA Astrophysics Data System (ADS)

    Lorch, T.; Bille, J.; Frieben, M.; Stephan, G.

    1986-04-01

    The scoring of structural chromosome aberrations in peripheral human blood lymphocytes can be used in biological dosimetry to estimate the radiation dose which an individual has received. Especially the dicentric chromosome is a rather specific indicator for an exposure to ionizing radiation. For statistical reasons, in the low dose range a great number of cells must be analysed, which is a very tedious task. The resulting high cost of a biological dose estimation limits the application of this method to cases of suspected irradiation for which physical dosimetry is not possible or not sufficient. Therefore an automated system has been designed to do the major part of the routine work. It uses a standard light microscope with motorized scanning stage, a Plumbicon TV-camera, a real-time hardware preprocessor, a binary and a grey level image buffer system. All computations are performed by a very powerful multi-microprocessor-system (POLYP) based on a MIMD-architecture. The task of the automated system can be split in finding the metaphases (see Figure 1) at low microscope magnification and scoring dicentrics at high magnification. The metaphase finding part has been completed and is now in routine use giving good results. The dicentric scoring part is still under development.

  15. Effects of Spaceflight on Cells of Bone Marrow Origin

    PubMed Central

    Özçivici, Engin

    2013-01-01

    Once only a subject for science fiction novels, plans for establishing habitation on space stations, the Moon, and distant planets now appear among the short-term goals of space agencies. This article reviews studies that present biomedical issues that appear to challenge humankind for long-term spaceflights. With particularly focus on cells of bone marrow origin, studies involving changes in bone, immune, and red blood cell populations and their functions due to extended weightlessness were reviewed. Furthermore, effects of mechanical disuse on primitive stem cells that reside in the bone marrow were also included in this review. Novel biomedical solutions using space biotechnology will be required in order to achieve the goal of space exploration without compromising the functions of bone marrow, as spaceflight appears to disrupt homeostasis for all given cell types. Conflict of interest:None declared. PMID:24385745

  16. Bone marrow invasion in multiple myeloma and metastatic disease.

    PubMed

    Vilanova, J C; Luna, A

    2016-04-01

    Magnetic resonance imaging (MRI) of the spine is the imaging study of choice for the management of bone marrow disease. MRI sequences enable us to integrate structural and functional information for detecting, staging, and monitoring the response the treatment of multiple myeloma and bone metastases in the spine. Whole-body MRI has been incorporated into different guidelines as the technique of choice for managing multiple myeloma and metastatic bone disease. Normal physiological changes in the yellow and red bone marrow represent a challenge in analyses to differentiate clinically significant findings from those that are not clinically significant. This article describes the findings for normal bone marrow, variants, and invasive processes in multiple myeloma and bone metastases.

  17. Autoimmune Lymphoproliferative Syndrome with Red Cell Aplasia.

    PubMed

    Meena, K R; Bisht, Supriya; Tamaria, K C

    2015-12-01

    Autoimmune Lymphoproliferative Syndrome (ALPS) is a rare inherited disorder of abnormal lymphocyte apoptosis, leading to chronic lymphoproliferation. It presents as lymphadenopathy, hepatosplenomegaly and autoimmune phenomena. Pure red cell aplasia is characterized by normochromic normocytic anemia, reticulocytopenia, and absence of erythroblasts from a normal bone marrow. Only few lymphoproliferative disorders have been associated with erythroid aplasia. The authors are reporting a case of ALPS associated with red cell aplasia in a 7-y-old girl.

  18. International intercomparison for criticality dosimetry: the case of biological dosimetry.

    PubMed

    Roy, L; Buard, V; Delbos, M; Durand, V; Paillole, N; Grégoire, E; Voisin, P

    2004-01-01

    The Institute of Radiation Protection and Nuclear Safety (IRSN) organized a biological dosimetry international intercomparison with the purpose of comparing (i) dicentrics yield produced in human lymphocytes; (ii) the gamma and neutron dose estimate according to the corresponding laboratory calibration curve. The experimental reactor SILENE was used with different configurations: bare source 4 Gy, lead shield 1 and 2 Gy and a 60Co source 2 Gy. An increasing variation of dicentric yield per cell was observed between participants when there were more damages in the samples. Doses were derived from the observed dicentric rates according to the dose-effect relationship provided by each laboratory. Differences in dicentric rate values are more important than those in the corresponding dose values. The doses obtained by the participants were found to be in agreement with the given physical dose within 20%. The evaluation of the respective gamma and neutron dose was achieved only by four laboratories, with some small variations among them.

  19. Computational methods in radionuclide dosimetry

    NASA Astrophysics Data System (ADS)

    Bardiès, M.; Myers, M. J.

    1996-10-01

    The various approaches in radionuclide dosimetry depend on the size and spatial relation of the sources and targets considered in conjunction with the emission range of the radionuclide used. We present some of the frequently reported computational techniques on the basis of the source/target size. For whole organs, or for sources or targets bigger than some centimetres, the acknowledged standard was introduced 30 years ago by the MIRD committee and is still being updated. That approach, based on the absorbed fraction concept, is mainly used for radioprotection purposes but has been updated to take into account the dosimetric challenge raised by therapeutic use of vectored radiopharmaceuticals. At this level, the most important computational effort is in the field of photon dosimetry. On the millimetre scale, photons can often be disregarded, and or electron dosimetry is generally reported. Heterogeneities at this level are mainly above the cell level, involving groups of cell or a part of an organ. The dose distribution pattern is often calculated by generalizing a point source dose distribution, but direct calculation by Monte Carlo techniques is also frequently reported because it allows media of inhomogeneous density to be considered. At the cell level, and electron (low-range or Auger) are the predominant emissions examined. Heterogeneities in the dose distribution are taken into account, mainly to determine the mean dose at the nucleus. At the DNA level, Auger electrons or -particles are considered from a microdosimetric point of view. These studies are often connected with radiobiological experiments on radionuclide toxicity.

  20. Emerging technological bases for retrospective dosimetry.

    PubMed

    Straume, T; Anspaugh, L R; Haskell, E H; Lucas, J N; Marchetti, A A; Likhtarev, I A; Chumak, V V; Romanyukha, A A; Khrouch, V T; Gavrilin YuI; Minenko, V F

    1997-01-01

    In this article we discuss examples of challenging problems in retrospective dosimetry and describe some promising solutions. The ability to make measurements by accelerator mass spectrometry and luminescence techniques promises to provide improved dosimetry for regions of Belarus, Ukraine and Russian Federation contaminated by radionuclides from the Chernobyl accident. In addition, it may soon be possible to resolve the large neutron discrepancy in the dosimetry system for Hiroshima through novel measurement techniques that can be used to reconstruct the fast-neutron fluence emitted by the bomb some 51 years ago. Important advances in molecular cytogenetics and electron paramagnetic resonance measurements have produced biodosimeters that show potential in retrospective dosimetry. The most promising of these are the frequency of reciprocal translocations measured in chromosomes of blood lymphocytes using fluorescence in situ hybridization and the electron paramagnetic resonance signal in tooth enamel.

  1. INTERSPECIES DOSIMETRY MODELS FOR PULMONARY PHARMACOLOGY

    EPA Science Inventory

    Interspecies Dosimetry Models for Pulmonary Pharmacology

    Ted B. Martonen, Jeffry D. Schroeter, and John S. Fleming

    Experimental Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangl...

  2. High-fidelity organic preservation of bone marrow in ca. 10 Ma amphibians

    NASA Astrophysics Data System (ADS)

    McNamara, Maria E.; Orr, Patrick J.; Kearns, Stuart L.; Alcalá, Luis; Anadón, Pere; Peñalver-Mollá, Enrique

    2006-08-01

    Bone marrow in ca. 10 Ma frogs and salamanders from the Miocene of Libros, Spain, represents the first fossilized example of this extremely decay-prone tissue. The bone marrow, preserved in three dimensions as an organic residue, retains the original texture and red and yellow color of hematopoietic and fatty marrow, respectively; moldic osteoclasts and vascular structures are also present. We attribute exceptional preservation of the fossilized bone marrow to cryptic preservation: the bones of the amphibians formed protective microenvironments, and inhibited microbial infiltration. Specimens in which bone marrow is preserved vary in their completeness and articulation and in the extent to which the body outline is preserved as a thin film of organically preserved bacteria. Cryptic preservation of these labile tissues is thus to a large extent independent of, and cannot be predicted by, the taphonomic history of the remainder of the specimen.

  3. Fat cotent of ectopic marrow implants and cellularity of resulting ossicles. [Rabbits

    SciTech Connect

    Maloney, M.A.; Flannery, M.L.; Patt, H.M.

    1980-11-01

    The capacity of marrow stroma to transfer a microenvironment conducive to hematopoiesis was studied in rabbits by means of subcutaneous implants of autologous marrow with variable hematopoietic cellularity and fat content as determined by histologic analysis. Cellularity of marrow in ossicles present at the implantation site 3 months later was found to be sigmoidally related to cellularity of the implant. Hypocellular marrow with fat content in excess of 50% was associated with onset of a sharp increase in saturated lipids as revealed by histochemistry. These results, which confirm and extend earlier qualitative observations of a difference in potential of red and yellow marrow upon ectopic implantation, are consistent with the putative regulatory role of stromal elements in hematopoiesis.

  4. Intra-Operative Dosimetry in Prostate Brachytherapy

    DTIC Science & Technology

    2006-11-01

    phantoms and pre-recorded patient data. 15. SUBJECT TERMS Prostate Brachytherapy, X-ray reconstruction, C-arm, TRUS 16. SECURITY CLASSIFICATION...prostate brachytherapy system that provides dosimetry analysis (Aim-2), and evaluate the system experimentally on phantoms and pre-recorded patient data...prostate brachytherapy system to enable dosimetry calculation Aim-3: Experimental Validation: Evaluate the performance of the RUF system on phantoms and

  5. Eye redness

    MedlinePlus

    Bloodshot eyes; Red eyes; Scleral injection; Conjunctival injection ... There are many causes of a red eye or eyes. Some are medical emergencies. Others are a cause for concern, but not an emergency. Many are nothing to worry about. Eye ...

  6. Audits for advanced treatment dosimetry

    NASA Astrophysics Data System (ADS)

    Ibbott, G. S.; Thwaites, D. I.

    2015-01-01

    Radiation therapy has advanced rapidly over the last few decades, progressing from 3D conformal treatment to image-guided intensity modulated therapy of several different flavors, both 3D and 4D and to adaptive radiotherapy. The use of intensity modulation has increased the complexity of quality assurance and essentially eliminated the physicist's ability to judge the validity of a treatment plan, even approximately, on the basis of appearance and experience. Instead, complex QA devices and procedures are required at the institutional level. Similarly, the assessment of treatment quality through remote and on-site audits also requires greater sophistication. The introduction of 3D and 4D dosimetry into external audit systems must follow, to enable quality assurance systems to perform meaningful and thorough audits.

  7. In vivo dosimetry in brachytherapy

    SciTech Connect

    Tanderup, Kari; Beddar, Sam; Andersen, Claus E.; Kertzscher, Gustavo; Cygler, Joanna E.

    2013-07-15

    In vivo dosimetry (IVD) has been used in brachytherapy (BT) for decades with a number of different detectors and measurement technologies. However, IVD in BT has been subject to certain difficulties and complexities, in particular due to challenges of the high-gradient BT dose distribution and the large range of dose and dose rate. Due to these challenges, the sensitivity and specificity toward error detection has been limited, and IVD has mainly been restricted to detection of gross errors. Given these factors, routine use of IVD is currently limited in many departments. Although the impact of potential errors may be detrimental since treatments are typically administered in large fractions and with high-gradient-dose-distributions, BT is usually delivered without independent verification of the treatment delivery. This Vision 20/20 paper encourages improvements within BT safety by developments of IVD into an effective method of independent treatment verification.

  8. Red Sea

    Atmospheric Science Data Center

    2013-04-16

    article title:  The Red Sea     View Larger Image ... 2000. Located between the East African coast and the Saudi Arabian peninsula, the Red Sea got its name because the blooms of a type of ... 2000 - The Red Sea between the East Africa coast and Saudi Arabian peninsula. project:  MISR category:  ...

  9. KSC CENTER DIRECTOR ACCEPTS PLAQUE FOR RECORD-SETTING BONE MARROW DONOR REGISTRATION DRIVE

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Kennedy Space Center's Bone Marrow Donor Registration Drive Chairman Dr. George A. Martin and Center Director Jay Honeycutt (left to right) accept a plaque from the Leukemia Society of America's Associate Executive Director Martin Bernstine and the American Red Cross' Southeast Regional Director Jeff Koenreich. Representatives from the American Red Cross and the Leukemia Society of America came to KSC to honor those involved in the record-setting Bone Marrow Donor Registration Drive held here earlier this year. Over 900 potential donors were added to the National Bone Marrow Registry as a result of the KSC drive. The drive established a new record for the most people registered in a single day for the American Red Cross in the three state region of which Florida is a part.

  10. Bone-marrow imaging with indium-111 chloride in aplastic anemia and myelofibrosis: concise communication

    SciTech Connect

    Sayle, B.A.; Helmer, R.E.; Birdsong, B.A.; Balachandran, S.; Gardner, F.H.

    1982-02-01

    Twenty-nine patients with aplastic anemia and 11 patients with myelofibrosis were evaluated with indium-111 chloride bone-marrow imaging, ferrokinetics, and bone-marrow core biopsies. There was good correlation between the erythrocyte cellularity of the marrow and the In-111 bone-marrow scan grades in most patients. In some, the overall scan grade tended to underestimate the erythroid elements because the core biopsy had been taken from the area of the greatest radionuclide concentration on the scan. In patients with aplastic anemia, there was good correlation between the plasma iron clearance t1/2 and the scan grade. Less agreement was found in the comparison between the Fe-59 sacral and organ counts and the red-cell iron utilization. In patients with myelofibrosis, there was poor correlation between the surface counts over the sacrum and the red-cell iron utilization. Plasma iron clearances were abnormally short and were unrelated to the transferrin saturation levels. Eighteen patients were studied several times to evaluate their responses to steroid therapy. In all, there was good correlation between the bone-marrow imaging, the erythrocyte cellularity, ferrokinetics, and the patient's response to therapy. Indium-111 bone-marrow imaging is useful both in evaluating marrow erythroid activity and in following the response to therapy in patients with these diseases.

  11. Uncertainty in 3D gel dosimetry

    NASA Astrophysics Data System (ADS)

    De Deene, Yves; Jirasek, Andrew

    2015-01-01

    Three-dimensional (3D) gel dosimetry has a unique role to play in safeguarding conformal radiotherapy treatments as the technique can cover the full treatment chain and provides the radiation oncologist with the integrated dose distribution in 3D. It can also be applied to benchmark new treatment strategies such as image guided and tracking radiotherapy techniques. A major obstacle that has hindered the wider dissemination of gel dosimetry in radiotherapy centres is a lack of confidence in the reliability of the measured dose distribution. Uncertainties in 3D dosimeters are attributed to both dosimeter properties and scanning performance. In polymer gel dosimetry with MRI readout, discrepancies in dose response of large polymer gel dosimeters versus small calibration phantoms have been reported which can lead to significant inaccuracies in the dose maps. The sources of error in polymer gel dosimetry with MRI readout are well understood and it has been demonstrated that with a carefully designed scanning protocol, the overall uncertainty in absolute dose that can currently be obtained falls within 5% on an individual voxel basis, for a minimum voxel size of 5 mm3. However, several research groups have chosen to use polymer gel dosimetry in a relative manner by normalizing the dose distribution towards an internal reference dose within the gel dosimeter phantom. 3D dosimetry with optical scanning has also been mostly applied in a relative way, although in principle absolute calibration is possible. As the optical absorption in 3D dosimeters is less dependent on temperature it can be expected that the achievable accuracy is higher with optical CT. The precision in optical scanning of 3D dosimeters depends to a large extend on the performance of the detector. 3D dosimetry with X-ray CT readout is a low contrast imaging modality for polymer gel dosimetry. Sources of error in x-ray CT polymer gel dosimetry (XCT) are currently under investigation and include inherent

  12. Skeletal dosimetry in cone beam computed tomography

    SciTech Connect

    Walters, B. R. B.; Ding, G. X.; Kramer, R.; Kawrakow, I.

    2009-07-15

    Cone beam computed tomography (CBCT) is a relatively new patient imaging technique that has proved invaluable for treatment target verification and patient positioning during image-guided radiotherapy (IGRT). It has been shown that CBCT results in additional dose to bone that may amount to 10% of the prescribed dose. In this study, voxelized human phantoms, FAX06 (adult female) and MAX06 (adult male), are used together with phase-space data collected from a realistic model of a CBCT imager to calculate dose in the red bone marrow (RBM) and bone surface cells (BSCs), the two organs at risk within the bone spongiosa, during simulated head and neck, chest and pelvis CBCT scans. The FAX06/MAX06 phantoms model spongiosa based on micro-CT images, filling the relevant phantom voxels, which are 0.12x0.12x0.12 cm{sup 3}, with 17x17x17 {mu}m{sup 3} microvoxels to form a micromatrix of trabecular bone and bone marrow. FAX06/MAX06 have already been implemented in an EGSnrc-based Monte Carlo code to simulate radiation transport in the phantoms; however, this study required significant modifications of the code to allow use of phase-space data from a simulated CBCT imager as a source and to allow scoring of total dose, RBM dose and BSC dose on a voxel-by-voxel basis. In simulated CBCT scans, the BSC dose is significantly greater than the dose to other organs at risk. For example, in a simulated head and neck scan, the average BSC dose is 25% higher than the average dose to eye lens ({approx}8.3 cGy), and 80% greater than the average dose to brain (5.7 cGy). Average dose to RBM, on the other hand, is typically only {approx}50% of the average BSC dose and less than the dose to other organs at risk (54% of the dose to eye lens and 76% of dose to brain in a head and neck scan). Thus, elevated dose in bone due to CBCT results in elevated BSC dose. This is potentially of concern when using CBCT in conjunction with radiotherapy treatment.

  13. CHANGES IN OUTLYING BONE MARROW ACCOMPANYING A LOCAL INCREASE OF TEMPERATURE WITHIN PHYSIOLOGICAL LIMITS

    PubMed Central

    Huggins, Charles; Blocksom, B. H.

    1936-01-01

    A great difference exists in the adult bone marrow of central bones as compared with outlying bones of the mammalia and avia, the distal bones being at a great disadvantage from the standpoint of blood cell production. Several experimental procedures are reported by which this disadvantage is overcome and in consequence fatty marrow of outlying bones is replaced by red marrow occurring chiefly at the epiphyseal regions, unless a low oxygen stimulus is also provided when marrow of the diaphysis becomes involved. A common factor in all of the experiments was an elevation of temperature beyond that prevailing in these distal regions, and it is felt that the evidence warrants the opinion that the cause of improvement is thermal. In some experiments, blood cell formation was increasing while the heat was adversely affecting the testis. The experiments permit construction of a general theory of fat distribution in bone marrow. In certain grafts of precartilage to other rats, normal differentiation into bone, cartilage, and marrow occurred, while in others cartilage and very small amounts of primitive marrow developed with slight, or no bone formation. Cartilage was always successfully engrafted. The capacity to form sinusoids in bone marrow is determined by the nature of the tissue rather than by the ingrowing endothelium. PMID:19870534

  14. Effect of syngeneic marrow injection upon recovery in sub- and near-lethally irradiated mice

    SciTech Connect

    Boggs, S.S.; Boggs, D.R.; Patrene, K.D.

    1989-06-01

    Mice were given sub-lethal (200-600 cGy) or near-lethal (800 cGy) whole body irradiation and the effect of injecting syngeneic marrow on subsequent hematopoietic recovery was studied. Marrow cell injection enhanced erythropoietic recovery after sub-lethal irradiation as reflected in hematocrit values and rate of appearance of /sup 59/Fe-labeled red cells in blood. However, this enhanced erythropoiesis was only seen in the spleen, and /sup 59/Fe uptake in marrow was reduced. When the irradiation dose was kept constant and the marrow dose increased from 10(5) to 10(6) to 10(7) cells, there was a somewhat erratic increase in spleen /sup 59/Fe and a decrease in marrow /sup 59/Fe uptake. When marrow cell number was kept constant and the dose of irradiation was increased from 200 to 400 to 600 to 800 cGy, there was an exponential increase in spleen /sup 59/Fe uptake but the marrow /sup 59/Fe uptake changed from depressed after lower doses to increased after 800 cGy. Cell injection after sub-lethal irradiation did not increase or decrease granulocytopoiesis. Injection of irradiated marrow cells also reduced marrow erythropoiesis and this was evident after both sub- and near-lethal irradiation. However, injection of irradiated cells did not increase splenic erythropoiesis. Following splenectomy, the depressed marrow erythropoiesis attending injection of viable cells was virtually eliminated but no increase was seen. These data suggest that the injection of autologous or syngeneic marrow may not be effective as a means of accelerating hematopoietic recovery after irradiation unless near-lethal or lethal dose have been received.

  15. Personnel neutron dosimetry at Department of Energy facilities

    SciTech Connect

    Brackenbush, L.W.; Endres, G.W.R.; Selby, J.M.; Vallario, E.J.

    1980-08-01

    This study assesses the state of personnel neutron dosimetry at DOE facilities. A survey of the personnel dosimetry systems in use at major DOE facilities was conducted, a literature search was made to determine recent advances in neutron dosimetry, and several dosimetry experts were interviewed. It was concluded that personnel neutron dosimeters do not meet current needs and that serious problems exist now and will increase in the future if neutron quality factors are increased and/or dose limits are lowered.

  16. Breast dosimetry in clinical mammography

    NASA Astrophysics Data System (ADS)

    Benevides, Luis Alberto Do Rego

    The objective of this study was show that a clinical dosimetry protocol that utilizes a dosimetric breast phantom series based on population anthropometric measurements can reliably predict the average glandular dose (AGD) imparted to the patient during a routine screening mammogram. In the study, AGD was calculated using entrance skin exposure and dose conversion factors based on fibroglandular content, compressed breast thickness, mammography unit parameters and modifying parameters for homogeneous phantom (phantom factor), compressed breast lateral dimensions (volume factor) and anatomical features (anatomical factor). The protocol proposes the use of a fiber-optic coupled (FOCD) or Metal Oxide Semiconductor Field Effect Transistor (MOSFET) dosimeter to measure the entrance skin exposure at the time of the mammogram without interfering with diagnostic information of the mammogram. The study showed that FOCD had sensitivity with less than 7% energy dependence, linear in all tube current-time product stations, and was reproducible within 2%. FOCD was superior to MOSFET dosimeter in sensitivity, reusability, and reproducibility. The patient fibroglandular content was evaluated using a calibrated modified breast tissue equivalent homogeneous phantom series (BRTES-MOD) designed from anthropomorphic measurements of a screening mammography population and whose elemental composition was referenced to International Commission on Radiation Units and Measurements Report 44 tissues. The patient fibroglandular content, compressed breast thickness along with unit parameters and spectrum half-value layer were used to derive the currently used dose conversion factor (DgN). The study showed that the use of a homogeneous phantom, patient compressed breast lateral dimensions and patient anatomical features can affect AGD by as much as 12%, 3% and 1%, respectively. The protocol was found to be superior to existing methodologies. In addition, the study population anthropometric

  17. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304... Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material to... nuclear accident is possible, shall provide nuclear accident dosimetry for those individuals. (b)...

  18. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304... Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material to... nuclear accident is possible, shall provide nuclear accident dosimetry for those individuals. (b)...

  19. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304... Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material to... nuclear accident is possible, shall provide nuclear accident dosimetry for those individuals. (b)...

  20. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304... Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material to... nuclear accident is possible, shall provide nuclear accident dosimetry for those individuals. (b)...

  1. 10 CFR 835.1304 - Nuclear accident dosimetry.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Nuclear accident dosimetry. 835.1304 Section 835.1304... Nuclear accident dosimetry. (a) Installations possessing sufficient quantities of fissile material to... nuclear accident is possible, shall provide nuclear accident dosimetry for those individuals. (b)...

  2. Dosimetry and Risk Assessment: Fundamental Concepts

    SciTech Connect

    Fisher, Darrell R.

    2005-12-29

    Radiation dosimetry is important for characterizing radiation exposures and for risk assessment. In a medical setting, dosimetry is important for evaluating the safety of administered radiopharmaceuticals and for planning the safe administration of therapeutic radionuclides. Environmental dosimetry helps establish the safety of radionuclide releases from electric power production and other human activities. Internal and external dosimetry help us understand the consequences of radiation exposure. The absorbed dose is the fundamental quantity in radiation dosimetry from which all other operational values in radiation protection are obtained. Equivalent dose to tissue and effective dose to the whole body are derivatives of absorbed dose and constructs of risk. Mathematical systems supported by computer software facilitate dose calculations and make it possible to estimate internal dose based on bioassay or other biokinetic data. Risk coefficients for radiation-induced cancer rely primarily on data from animal studies and long-term observations of the Hiroshima and Nagasaki bomb survivors. Low-dose research shows that mechanisms of radiation interactions with tissue are dose-dependent, but the resulting biological effects are not necessarily linear with absorbed dose. Thus, the analysis of radiation effects and associated risks must account for the influences of microscopic energy distributions at the cellular level, dose-rate, cellular repair of sub-lethal radiation damage, and modifying factors such as bystander effects, adaptive response, and genomic instability.

  3. Seventh Personnel Dosimetry Intercomparison Study

    SciTech Connect

    Swaja, R.E.; Sims, C.S.; Greene, R.T.

    1981-12-01

    The Seventh Personnel Dosimetry Intercomparison Study was conducted March 31-April 10, 1981, at the Oak Ridge National Laboratory. Dosimeters from 34 participating agencies were mounted on anthropomorphic phantoms and exposed to a range of low-level dose equivalents (1.5-15.0mSv neutron and 0.1-2.8 mSv gamma) which could be encountered during routine personnel monitoring in mixed radiation fields. The Health Physics Research Reactor, operating in the steady-state mode, served as the source of radiation for two equivalent sets of six separate exposures. Lucite and concrete shields along with the unshielded reactor provided three different neutron and gamma spectra for five of the exposures in each set. Results reported by the participating agencies showed that no single type of neutron dosimeter exhibited acceptable performance characteristics for all mixed-field environments encountered in this study. Film, TLD, and TLD-albed dosimeters were found to be inadequate for neutron dose equivalent measurements when large numbers of slow neutrons are present unless significant corrections are made to measured results. Track dosimeters indicated the least sensitivity to spectral characteristics, but did not always yield to the most accurate results. Gamma dose measurements showed that TLD-700 dosimeters produced significantly more accurate results than film dosimeters which tend to overestimate gamma doses in mixed radiation fields.

  4. Patient dosimetry in nuclear medicine.

    PubMed

    Mattsson, Sören

    2015-07-01

    In diagnostic nuclear medicine, the biokinetics of the radiopharmaceutical (actually of the radionuclide) is determined for a number of representative patients. At therapy, it is essential to determine the patient's individual biokinetics of the radiopharmaceutical in order to calculate the absorbed doses to critical normal organs/tissues and to the target volume(s) with high accuracy. For the diagnostic situations, there is still a lack of quantitative determinations of the organ/tissue contents of radiopharmaceuticals and their variation with time. Planar gamma camera imaging using the conjugate view technique combined with a limited number of SPECT/CT images is the main method for such studies. In a similar way, PET/CT is used for 3D image-based internal dosimetry for PET substances. The transition from stylised reference phantoms to voxel phantoms will lead to improved dose estimates for diagnostic procedures. Examples of dose coefficients and effective doses for diagnostic substances are given. For the therapeutic situation, a pre-therapeutic low activity administration is used for quantitative measurements of organ/tissue distribution data by a gamma camera or a SPECT- or PET-unit. Together with CT and/or MR images this will be the base for individual dose calculations using Monte Carlo technique. Treatments based on administered activity should only be used if biological variations between patients are small or if a pre-therapeutic activity administration is impossible.

  5. What Are Bone Marrow Tests?

    MedlinePlus

    ... for people with certain bleeding disorders such as hemophilia. Bone marrow tests can be done in a ... reading Anemia Aplastic Anemia Blood Tests Clinical Trials Hemophilia Thrombocythemia and Thrombocytosis Thrombocytopenia Rate This Content: Updated: ...

  6. Aspiration and Biopsy: Bone Marrow

    MedlinePlus

    ... in determining treatment and prognosis) viral, bacterial, or fungal infections in the bone marrow that might be causing lasting fever or other symptoms certain genetic diseases (such as lipid storage diseases) They also ...

  7. Aspiration and Biopsy: Bone Marrow

    MedlinePlus

    ... in determining treatment and prognosis) viral, bacterial, or fungal infections in the bone marrow that might be causing a lasting fever or other symptoms certain genetic diseases (such as lipid storage diseases) They also ...

  8. 3-D Imaging Based, Radiobiological Dosimetry

    PubMed Central

    Sgouros, George; Frey, Eric; Wahl, Richard; He, Bin; Prideaux, Andrew; Hobbs, Robert

    2008-01-01

    Targeted radionuclide therapy holds promise as a new treatment against cancer. Advances in imaging are making it possible to evaluate the spatial distribution of radioactivity in tumors and normal organs over time. Matched anatomical imaging such as combined SPECT/CT and PET/CT have also made it possible to obtain tissue density information in conjunction with the radioactivity distribution. Coupled with sophisticated iterative reconstruction algorithims, these advances have made it possible to perform highly patient-specific dosimetry that also incorporates radiobiological modeling. Such sophisticated dosimetry techniques are still in the research investigation phase. Given the attendant logistical and financial costs, a demonstrated improvement in patient care will be a prerequisite for the adoption of such highly-patient specific internal dosimetry methods. PMID:18662554

  9. INTEGRATED OPERATIONAL DOSIMETRY SYSTEM AT CERN.

    PubMed

    Dumont, Gérald; Pedrosa, Fernando Baltasar Dos Santos; Carbonez, Pierre; Forkel-Wirth, Doris; Ninin, Pierre; Fuentes, Eloy Reguero; Roesler, Stefan; Vollaire, Joachim

    2016-11-24

    CERN, the European Organization for Nuclear Research, upgraded its operational dosimetry system in March 2013 to be prepared for the first Long Shutdown of CERN's facilities. The new system allows the immediate and automatic checking and recording of the dosimetry data before and after interventions in radiation areas. To facilitate the analysis of the data in context of CERN's approach to As Low As Reasonably Achievable (ALARA), this new system is interfaced to the Intervention Management Planning and Coordination Tool (IMPACT). IMPACT is a web-based application widely used in all CERN's accelerators and their associated technical infrastructures for the planning, the coordination and the approval of interventions (work permit principle). The coupling of the operational dosimetry database with the IMPACT repository allows a direct and almost immediate comparison of the actual dose with the estimations, in addition to enabling the configuration of alarm levels in the dosemeter in function of the intervention to be performed.

  10. Dosimetry procedures for an industrial irradiation plant

    NASA Astrophysics Data System (ADS)

    Grahn, Ch.

    Accurate and reliable dosimetry procedures constitute a very important part of process control and quality assurance at a radiation processing plant. γ-Dose measurements were made on the GBS 84 irradiator for food and other products on pallets or in containers. Chemical dosimeters wre exposed in the facility under conditions of the typical plant operation. The choice of the dosimeter systems employed was based on the experience in chemical dosimetry gained over several years. Dose uniformity information was obtained in air, spices, bulbs, feeds, cosmetics, plastics and surgical goods. Most products currently irradiated require dose uniformity which can be efficiently provided by pallet or box irradiators like GBS 84. The radiation performance characteristics and some dosimetry procedures are discussed.

  11. Dosimetry of the Atomic Bomb Survivors

    SciTech Connect

    Sinclair, W.K.; Failla, P.

    1981-12-01

    A brief account of the presentations and discussions at the Late Effects Workshop on Dosimetry of the Atomic Bomb Survivors held in conjunction with the 29th Annual Meeting of the Radiation Reserch Society in Minneapolis, MN, on May 32, 1981 is presented. The following five papers are briefly reviewed: 1)Radiobiological significance of the Hiroshima/Nagasaki data by V.P. Bond; 2)Revised Dose Estimates at Hiroshima and Nagasaki, by W.E. Loewe; 3)Review of dosimetry for the Japanese atomic bomb survivors by G.D. Kerr; 4)Ichiban: numberoriginal studies, by J. Auxier; and 5)NCRP's involvement in the Hiroshima and Nagasaki Dosimetry, by H.O. Wyckoff. (JMT)

  12. Protocol for emergency EPR dosimetry in fingernails.

    PubMed

    Trompier, F; Kornak, L; Calas, C; Romanyukha, A; Leblanc, B; Mitchell, C A; Swartz, H M; Clairand, I

    2007-08-01

    There is an increased need for after-the-fact dosimetry because of the high risk of radiation exposures due to terrorism or accidents. In case of such an event, a method is needed to make measurements of dose in a large number of individuals rapidly and with sufficient accuracy to facilitate effective medical triage. Dosimetry based on EPR measurements of fingernails potentially could be an effective tool for this purpose. This paper presents the first operational protocols for EPR fingernail dosimetry, including guidelines for collection and storage of samples, parameters for EPR measurements, and the method of dose assessment. In a blinded test of this protocol application was carried out on nails freshly sampled and irradiated to 4 and 20 Gy; this protocol gave dose estimates with an error of less than 30%.

  13. Small Field: dosimetry in electron disequilibrium region

    NASA Astrophysics Data System (ADS)

    Zhu, Timothy C.

    2010-11-01

    Small fields are more commonly used for radiation therapy because of the development of IMRT, stereotactic radiosurgery, and other special equipments such as Cyberknife and Tomotherapy. The dosimetry in the sub-centimeter field can result in substantial uncertainties because of the presence of electron disequilibrium due to the large dose gradients in the field. It is further complicated by the introduction of various radiation detectors, which usually perturb the conditions of disequilibrium. Hence additional corrections are required to maintain the dosimetric accuracy previously achieved for standard radiation dosimetry. A review of small field dosimetry provides some insights into the methods to characterize the detector convolution kernel and other methods to characterize detector perturbation effect.

  14. Czech results at criticality dosimetry intercomparison 2002.

    PubMed

    Frantisek, Spurný; Jaroslav, Trousil

    2004-01-01

    Two criticality dosimetry systems were tested by Czech participants during the intercomparison held in Valduc, France, June 2002. The first consisted of the thermoluminescent detectors (TLDs) (Al-P glasses) and Si-diodes as passive neutron dosemeters. Second, it was studied to what extent the individual dosemeters used in the Czech routine personal dosimetry service can give a reliable estimation of criticality accident exposure. It was found that the first system furnishes quite reliable estimation of accidental doses. For routine individual dosimetry system, no important problems were encountered in the case of photon dosemeters (TLDs, film badge). For etched track detectors in contact with the 232Th or 235U-Al alloy, the track density saturation for the spark counting method limits the upper dose at approximately 1 Gy for neutrons with the energy >1 MeV.

  15. Reactor Dosimetry State of the Art 2008

    NASA Astrophysics Data System (ADS)

    Voorbraak, Wim; Debarberis, Luigi; D'Hondt, Pierre; Wagemans, Jan

    2009-08-01

    Oral session 1: Retrospective dosimetry. Retrospective dosimetry of VVER 440 reactor pressure vessel at the 3rd unit of Dukovany NPP / M. Marek ... [et al.]. Retrospective dosimetry study at the RPV of NPP Greifswald unit 1 / J. Konheiser ... [et al.]. Test of prototype detector for retrospective neutron dosimetry of reactor internals and vessel / K. Hayashi ... [et al.]. Neutron doses to the concrete vessel and tendons of a magnox reactor using retrospective dosimetry / D. A. Allen ... [et al.]. A retrospective dosimetry feasibility study for Atucha I / J. Wagemans ... [et al.]. Retrospective reactor dosimetry with zirconium alloy samples in a PWR / L. R. Greenwood and J. P. Foster -- Oral session 2: Experimental techniques. Characterizing the Time-dependent components of reactor n/y environments / P. J. Griffin, S. M. Luker and A. J. Suo-Anttila. Measurements of the recoil-ion response of silicon carbide detectors to fast neutrons / F. H. Ruddy, J. G. Seidel and F. Franceschini. Measurement of the neutron spectrum of the HB-4 cold source at the high flux isotope reactor at Oak Ridge National Laboratory / J. L. Robertson and E. B. Iverson. Feasibility of cavity ring-down laser spectroscopy for dose rate monitoring on nuclear reactor / H. Tomita ... [et al.]. Measuring transistor damage factors in a non-stable defect environment / D. B. King ... [et al.]. Neutron-detection based monitoring of void effects in boiling water reactors / J. Loberg ... [et al.] -- Poster session 1: Power reactor surveillance, retrospective dosimetry, benchmarks and inter-comparisons, adjustment methods, experimental techniques, transport calculations. Improved diagnostics for analysis of a reactor pulse radiation environment / S. M. Luker ... [et al.]. Simulation of the response of silicon carbide fast neutron detectors / F. Franceschini, F. H. Ruddy and B. Petrović. NSV A-3: a computer code for least-squares adjustment of neutron spectra and measured dosimeter responses / J. G

  16. Red blood cell decreases of microgravity

    NASA Technical Reports Server (NTRS)

    Johnson, P. C.

    1985-01-01

    Postflight decreases in red blood cell mass (RBCM) have regularly been recorded after exposure to microgravity. These 5-25 percent decreases do not relate to the mission duration, workload, caloric intake or to the type of spacecraft used. The decrease is accompanied by normal red cell survivals, increased ferritin levels, normal radioactive iron studies, and increases in mean red blood cell volume. Comparable decreases in red blood cell mass are not found after bed rest, a commonly used simulation of the microgravity state. Inhibited bone marrow erythropoiesis has not been proven to date, although reticulocyte numbers in the peripheral circulation are decreased about 50 percent. To date, the cause of the microgravity induced decreases in RBCM is unknown. Increased splenic trapping of circulating red blood cells seem the most logical way to explain the results obtained.

  17. Evaluation of the in vivo genotoxicity of Allura Red AC (Food Red No. 40).

    PubMed

    Honma, Masamitsu

    2015-10-01

    Allura Red AC (Food Red No. 40) is a red azo dye that is used for food coloring in beverage and confectionary products. However, its genotoxic properties remain controversial. To clarify the in vivo genotoxicity, we treated mice with Allura Red AC and investigated the induction of DNA damage (liver, glandular stomach), clastogenicity/anuegenicity (bone marrow), and mutagenicity (liver, glandular stomach) using Comet assays, micronucleus tests, and transgenic gene mutation assays, respectively. All studies were conducted in accordance with the Organization for Economic Co-operation and Development (OECD) guideline. Although Allura Red AC was administered up to the maximum doses recommended by the OECD guideline, no genotoxic effect was observed in any of the genotoxic endpoints. These data clearly show no evidence of in vivo genotoxic potential of Allura Red AC administered up to the maximum doses in mice.

  18. Advances in personnel neutron dosimetry: part 2

    SciTech Connect

    Vallario, E.; Faust, L.

    1983-08-01

    A continuation of the advances in personnel neutron dosimetry research programs and technology transfer reviews work on active dosimeters, electronic devices that determine the dose equivalent to a worker during an exposure to neutron radiation. Active dosemeters are routinely used for gamma radiation dosimetry. Experience with neutron-sensitive pocket rem-meters at several DOE laboratories covers three prototypes. Pocket rem-meters work well for detecting neutrons over a wide energy range. They give instantaneous readout of the accumulated neutron dose-equivalent. 1 figure.

  19. Practical neutron dosimetry at high energies

    SciTech Connect

    McCaslin, J.B.; Thomas, R.H.

    1980-10-01

    Dosimetry at high energy particle accelerators is discussed with emphasis on physical measurements which define the radiation environment and provide an immutable basis for the derivation of any quantities subsequently required for risk evaluation. Results of inter-laboratory dosimetric comparisons are reviewed and it is concluded that a well-supported systematic program is needed which would make possible detailed evaluations and inter-comparisons of instruments and techniques in well characterized high energy radiation fields. High-energy dosimetry is so coupled with radiation transport that it is clear their study should proceed concurrently.

  20. Technical basis for internal dosimetry at Hanford

    SciTech Connect

    Sula, M.J.; Carbaugh, E.H.; Bihl, D.E.

    1989-04-01

    The Hanford Internal Dosimetry Program, administered by Pacific Northwest Laboratory for the US Department of Energy, provides routine bioassay monitoring for employees who are potentially exposed to radionuclides in the workplace. This report presents the technical basis for routine bioassay monitoring and the assessment of internal dose at Hanford. The radionuclides of concern include tritium, corrosion products (/sup 58/Co, /sup 60/Co, /sup 54/Mn, and /sup 59/Fe), strontium, cesium, iodine, europium, uranium, plutonium, and americium. Sections on each of these radionuclides discuss the sources and characteristics; dosimetry; bioassay measurements and monitoring; dose measurement, assessment, and mitigation; and bioassay follow-up treatment. 64 refs., 42 figs., 118 tabs.

  1. Technical basis for internal dosimetry at Hanford

    SciTech Connect

    Sula, M.J.; Carbaugh, E.H.; Bihl, D.E.

    1991-07-01

    The Hanford Internal Dosimetry Program, administered by Pacific Northwest Laboratory for the US Department of Energy, provides routine bioassay monitoring for employees who are potentially exposed to radionuclides in the workplace. This report presents the technical basis for routine bioassay monitoring and the assessment of internal dose at Hanford. The radionuclides of concern include tritium, corrosion products ({sup 58}Co, {sup 60}Co, {sup 54}Mn, and {sup 59}Fe), strontium, cesium, iodine, europium, uranium, plutonium, and americium,. Sections on each of these radionuclides discuss the sources and characteristics; dosimetry; bioassay measurements and monitoring; dose measurement, assessment, and mitigation and bioassay follow-up treatment. 78 refs., 35 figs., 115 tabs.

  2. Applicability of Topaz Composites to Electron Dosimetry

    NASA Astrophysics Data System (ADS)

    Bomfim, K. S.; Souza, D. N.

    2010-11-01

    Thermoluminescent dosimetric topaz properties have been investigated and the results have shown that this mineral presents characteristics of a good dosimeter mainly in doses evaluation in radiotherapy with photons beams in radiotherapy. Typical applications of thermoluminescent dosimeters in radiotherapy are: in vivo dosimetry on patients (either as a routine quality assurance procedure or for dose monitoring in special cases); verification of treatment techniques; dosimetry audits; and comparisons among hospitals. The mean aim of this work was to evaluate the efficiency of topaz-Teflon pellets as thermoluminescent dosimeters in high-energy electron beams used to radiotherapy. Topaz-Teflon pellets were used as TLD.

  3. SNL RML recommended dosimetry cross section compendium

    SciTech Connect

    Griffin, P.J.; Kelly, J.G.; Luera, T.F.; VanDenburg, J.

    1993-11-01

    A compendium of dosimetry cross sections is presented for use in the characterization of fission reactor spectrum and fluence. The contents of this cross section library are based upon the ENDF/B-VI and IRDF-90 cross section libraries and are recommended as a replacement for the DOSCROS84 multigroup library that is widely used by the dosimetry community. Documentation is provided on the rationale for the choice of the cross sections selected for inclusion in this library and on the uncertainty and variation in cross sections presented by state-of-the-art evaluations.

  4. Recent progresses in tritium radioecology and dosimetry

    SciTech Connect

    Galeriu, D.; Davis, P.; Raskob, W.; Melintescu, A.

    2008-07-15

    In this paper, some aspects of recent progress in tritium radioecology and dosimetry are presented, with emphasis on atmospheric releases to terrestrial ecosystems. The processes involved in tritium transfer through the environment are discussed, together with the current status of environmental tritium models. Topics include the deposition and reemission of HT and HTO, models for the assessment of routine and accidental HTO emissions, a new approach to modeling the dynamics of tritium in mammals, the dose consequences of tritium releases and aspects of human dosimetry. The need for additional experimental data is identified, together with the attributes that would be desirable in the next generation of tritium codes. (authors)

  5. A prototype quantitative film scanner for radiochromic film dosimetry

    SciTech Connect

    Ranade, Manisha K.; Li, Jonathan G.; Dubose, Ryan S.; Kozelka, Jakub; Simon, William E.; Dempsey, James F.

    2008-02-15

    We have developed a high resolution, quantitative, two-dimensional optical film scanner for use with a commercial high sensitivity radiochromic film (RCF) for measuring single fraction external-beam radiotherapy dose distributions. The film scanner was designed to eliminate artifacts commonly observed in RCF dosimetry. The scanner employed a stationary light source and detector with a moving antireflective glass film platen attached to a high precision computerized X-Y translation stage. An ultrabright red light emitting diode (LED) with a peak output at 633 nm and full width at half maximum (FWHM) of 16 nm was selected as the scanner light source to match the RCF absorption peak. A dual detector system was created using two silicon photodiode detectors to simultaneously measure incident and transmitted light. The LED light output was focused to a submillimeter (FWHM 0.67 mm) spot size, which was determined from a scanning knife-edge technique for measuring Gaussian optical beams. Data acquisition was performed with a 16-bit A/D card in conjunction with commercial software. The linearity of the measured densities on the scanner was tested using a calibrated neutral-density step filter. Sensitometric curves and three IMRT field scans were acquired with a spatial resolution of 1 mm for both radiographic film and RCF. The results were compared with measurements taken with a commercial diode array under identical delivery conditions. The RCF was rotated by 90 deg. and rescanned to study orientation effects. Comparison between the RCF and the diode array measurements using percent dose difference and distance-to-agreement criteria produced average passing rates of 99.0% using 3%/3 mm criteria and 96.7% using 2%/2 mm criteria. The same comparison between the radiographic film and diode array measurements resulted in average passing rates 96.6% and 91.6% for the above two criteria, respectively. No measurable light-scatter or interference scanner artifacts were observed

  6. A protocol for EBT3 radiochromic film dosimetry using reflection scanning

    SciTech Connect

    Papaconstadopoulos, Pavlos Hegyi, Gyorgy; Seuntjens, Jan; Devic, Slobodan

    2014-12-15

    Purpose: To evaluate the performance of the EBT3 radiochromic film dosimetry system using reflection measurements and to suggest a calibration protocol for precise and accurate reflection film dosimetry. Methods: A set of 14 Gafchromic EBT3 film pieces were irradiated to various doses ranging from 0 to 8 Gy and subsequently scanned using both the reflection and transmission mode. Scanning resolution varied from 50 to 508 dpi (0.5–0.05 mm/pixel). Both the red and green color channels of scanned images were used to relate the film response to the dose. A sensitivity, uncertainty, and accuracy analysis was performed for all scanning modes and color channels. The total uncertainty, along with the fitting and experimental uncertainty components, was identified and analyzed. A microscope resolution target was used to evaluate possible resolution losses under reflection scanning. The calibration range was optimized for reflection scanning in the low (<2 Gy) and high (>2 Gy) dose regions based on the reported results. Results: Reflection scanning using the red channel exhibited the highest sensitivity among all modes, being up to 150% higher than transmission mode in the red channel for the lowest dose level. Furthermore, there was no apparent loss in resolution between the two modes. However, higher uncertainties and reduced accuracy were observed for the red channel under reflection mode, especially at dose levels higher than 2 Gy. These uncertainties were mainly attributed to saturation effects which were translated in poor fitting results. By restricting the calibration to the 0–2 Gy dose range, the situation is reversed and the red reflection mode was superior to the transmission mode. For higher doses, the green channel in reflection mode presented comparable results to the red transmission. Conclusions: A two-color reflection scanning protocol can be suggested for EBT3 radiochromic film dosimetry using the red channel for doses less than 2 Gy and the green

  7. An image-based skeletal dosimetry model for the ICRP reference adult male--internal electron sources.

    PubMed

    Hough, Matthew; Johnson, Perry; Rajon, Didier; Jokisch, Derek; Lee, Choonsik; Bolch, Wesley

    2011-04-21

    In this study, a comprehensive electron dosimetry model of the adult male skeletal tissues is presented. The model is constructed using the University of Florida adult male hybrid phantom of Lee et al (2010 Phys. Med. Biol. 55 339-63) and the EGSnrc-based Paired Image Radiation Transport code of Shah et al (2005 J. Nucl. Med. 46 344-53). Target tissues include the active bone marrow, associated with radiogenic leukemia, and total shallow marrow, associated with radiogenic bone cancer. Monoenergetic electron emissions are considered over the energy range 1 keV to 10 MeV for the following sources: bone marrow (active and inactive), trabecular bone (surfaces and volumes), and cortical bone (surfaces and volumes). Specific absorbed fractions are computed according to the MIRD schema, and are given as skeletal-averaged values in the paper with site-specific values reported in both tabular and graphical format in an electronic annex available from http://stacks.iop.org/0031-9155/56/2309/mmedia. The distribution of cortical bone and spongiosa at the macroscopic dimensions of the phantom, as well as the distribution of trabecular bone and marrow tissues at the microscopic dimensions of the phantom, is imposed through detailed analyses of whole-body ex vivo CT images (1 mm resolution) and spongiosa-specific ex vivo microCT images (30 µm resolution), respectively, taken from a 40 year male cadaver. The method utilized in this work includes: (1) explicit accounting for changes in marrow self-dose with variations in marrow cellularity, (2) explicit accounting for electron escape from spongiosa, (3) explicit consideration of spongiosa cross-fire from cortical bone, and (4) explicit consideration of the ICRP's change in the surrogate tissue region defining the location of the osteoprogenitor cells (from a 10 µm endosteal layer covering the trabecular and cortical surfaces to a 50 µm shallow marrow layer covering trabecular and medullary cavity surfaces). Skeletal

  8. An image-based skeletal dosimetry model for the ICRP reference adult male—internal electron sources

    NASA Astrophysics Data System (ADS)

    Hough, Matthew; Johnson, Perry; Rajon, Didier; Jokisch, Derek; Lee, Choonsik; Bolch, Wesley

    2011-04-01

    In this study, a comprehensive electron dosimetry model of the adult male skeletal tissues is presented. The model is constructed using the University of Florida adult male hybrid phantom of Lee et al (2010 Phys. Med. Biol. 55 339-63) and the EGSnrc-based Paired Image Radiation Transport code of Shah et al (2005 J. Nucl. Med. 46 344-53). Target tissues include the active bone marrow, associated with radiogenic leukemia, and total shallow marrow, associated with radiogenic bone cancer. Monoenergetic electron emissions are considered over the energy range 1 keV to 10 MeV for the following sources: bone marrow (active and inactive), trabecular bone (surfaces and volumes), and cortical bone (surfaces and volumes). Specific absorbed fractions are computed according to the MIRD schema, and are given as skeletal-averaged values in the paper with site-specific values reported in both tabular and graphical format in an electronic annex available from http://stacks.iop.org/0031-9155/56/2309/mmedia. The distribution of cortical bone and spongiosa at the macroscopic dimensions of the phantom, as well as the distribution of trabecular bone and marrow tissues at the microscopic dimensions of the phantom, is imposed through detailed analyses of whole-body ex vivo CT images (1 mm resolution) and spongiosa-specific ex vivo microCT images (30 µm resolution), respectively, taken from a 40 year male cadaver. The method utilized in this work includes: (1) explicit accounting for changes in marrow self-dose with variations in marrow cellularity, (2) explicit accounting for electron escape from spongiosa, (3) explicit consideration of spongiosa cross-fire from cortical bone, and (4) explicit consideration of the ICRP's change in the surrogate tissue region defining the location of the osteoprogenitor cells (from a 10 µm endosteal layer covering the trabecular and cortical surfaces to a 50 µm shallow marrow layer covering trabecular and medullary cavity surfaces). Skeletal

  9. [Normal bone marrow and common reactive alterations].

    PubMed

    Tzankov, A; Dirnhofer, S; Beham-Schmid, C

    2012-11-01

    Histological examination of bone marrow biopsies is an important and powerful diagnostic tool to assess various hematological and non-hematological disorders. Morphological examination of such biopsies requires knowledge of the composition of normal bone marrow and its variations, such as age-related changes. Diagnostic problems may arise due to poor specimen quality, insufficient sections or stainings and insufficient experience with reactive bone marrow changes which occasionally resemble neoplastic disorders. Reactive bone marrow processes can affect one or more hematopoietic cell lines, lead to disruption of the normal architecture and specifically affect the bone marrow stroma. Optimal bone marrow diagnosis requires adequately stained slides and, when needed, immunophenotyping and molecular examinations. Furthermore, rather than biopsy interpretation of other organs, pathologists routinely need clinical history information for correct interpretation and diagnosis of bone marrow changes. In this article, the normal features of bone marrow as well as the most frequent reactive bone marrow alterations are described.

  10. Red Sky with Red Mesa

    ScienceCinema

    None

    2016-07-12

    The Red Sky/Red Mesa supercomputing platform dramatically reduces the time required to simulate complex fuel models, from 4-6 months to just 4 weeks, allowing researchers to accelerate the pace at which they can address these complex problems. Its speed also reduces the need for laboratory and field testing, allowing for energy reduction far beyond data center walls.

  11. A stochastic model of radiation-induced bone marrow damage

    SciTech Connect

    Cotlet, G.; Blue, T.E.

    2000-03-01

    A stochastic model, based on consensus principles from radiation biology, is used to estimate bone-marrow stem cell pool survival (CFU-S and stroma cells) after irradiation. The dose response model consists of three coupled first order linear differential equations which quantitatively describe time dependent cellular damage, repair, and killing of red bone marrow cells. This system of differential equations is solved analytically through the use of a matrix approach for continuous and fractionated irradiations. The analytic solutions are confirmed through the dynamical solution of the model equations using SIMULINK. Rate coefficients describing the cellular processes of radiation damage and repair, extrapolated to humans from animal data sets and adjusted for neutron-gamma mixed fields, are employed in a SIMULINK analysis of criticality accidents. The results show that, for the time structures which may occur in criticality accidents, cell survival is established mainly by the average dose and dose rate.

  12. A-bomb survivor dosimetry update

    SciTech Connect

    Loewe, W.E.

    1982-06-01

    A-bomb survivor data have been generally accepted as applicable. Also, the initial radiations have tended to be accepted as the dominant radiation source for all survivors. There was general acceptance of the essential reliability of both the biological effects data and the causative radiation dose values. There are considerations casting doubt on these acceptances, but very little quantification of th implied uncertainties has been attempted. The exception was A-bomb survivor dosimetry, where free-field kerma values for initial radiations were thought to be accurate to about 30%, and doses to individual survivors were treated as effectively error-free. In 1980, a major challenge to the accepted A-bomb survivor dosimetry was announced, and was quickly followed by a succession of explanations and displays showing the soundness of that challenge. In fact, a complete replacement set of free-field kerma values was provided which was suitable for use in constructing an entire new dosimetry for Hiroshima and Nagasaki. The new values showed many changes greater than the accepted 30% uncertainty. An approximate new dosimetry was indeed constructed, and used to convert existing leukemia cause-and-effect data from the old to the new dose values, by way of assessing the impact. (ERB)

  13. Personnel radiation dosimetry symposium: program and abstracts

    SciTech Connect

    Not Available

    1984-10-01

    The purpose was to provide applied and research dosimetrists with sufficient information to evaluate the status and direction of their programs relative to the latest guidelines and techniques. A technical program was presented concerning experience, requirements, and advances in gamma, beta, and neutron personnel dosimetry.

  14. Distribution effectiveness for space radiation dosimetry

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.

    1975-01-01

    A simplified risk basis and a theory of hematological response are presented and applied to the problem of dosimetry in the manned space program. Unlike previous studies, the current work incorporates radiation exposure distribution effects into its definition of dose equivalent. The fractional cell lethality model for prediction of hematological response is integral in the analysis.

  15. Computational Techniques of Electromagnetic Dosimetry for Humans

    NASA Astrophysics Data System (ADS)

    Hirata, Akimasa; Fujiwara, Osamu

    There has been increasing public concern about the adverse health effects of human exposure to electromagnetic fields. This paper reviews the rationale of international safety guidelines for human protection against electromagnetic fields. Then, this paper also presents computational techniques to conduct dosimetry in anatomically-based human body models. Computational examples and remaining problems are also described briefly.

  16. Development of A-bomb survivor dosimetry

    SciTech Connect

    Kerr, G.D.

    1995-12-31

    An all important datum in risk assessment is the radiation dose to individual survivors of the bombings in Hiroshima and Nagasaki. The first set of dose estimates for survivors was based on a dosimetry system developed in 1957 by the Oak Ridge National Laboratory (ORNL). These Tentative 1957 Doses (T57D) were later replaced by a more extensive and refined set of Tentative 1965 Doses (T65D). The T65D system of dose estimation for survivors was also developed at ORNL and served as a basis for risk assessment throughout the 1970s. In the late 1970s, it was suggested that there were serious inadequacies with the T65D system, and these inadequacies were the topic of discussion at two symposia held in 1981. In early 1983, joint US- Japan research programs were established to conduct a thorough review of all aspects of the radiation dosimetry for the Hiroshima and Nagasaki A-bomb survivors. A number of important contributions to this review were made by ORNL staff members. The review was completed in 1986 and a new Dosimetry System 1986 (DS86) was adopted for use. This paper discusses the development of the various systems of A-bomb survivor dosimetry, and the status of the current DS86 system as it is being applied in the medical follow-up studies of the A-bomb survivors and their offspring.

  17. Dosimetry implant for treating restenosis and hyperplasia

    DOEpatents

    Srivastava, Suresh; Gonzales, Gilbert R; Howell, Roger W; Bolch, Wesley E; Adzic, Radoslav

    2014-09-16

    The present invention discloses a method of selectively providing radiation dosimetry to a subject in need of such treatment. The radiation is applied by an implant comprising a body member and .sup.117mSn electroplated at selected locations of the body member, emitting conversion electrons absorbed immediately adjacent selected locations while not affecting surrounding tissue outside of the immediately adjacent area.

  18. From ``micro`` to ``macro`` internal dosimetry

    SciTech Connect

    Fisher, D.R.

    1994-06-01

    Radiation dose is the amount of radiation energy deposited per unit mass of absorbing tissue. Internal dosimetry applies to assessments of dose to internal organs from penetrating radiation sources outside the body and from radionuclides taken into the body. Dosimetry is essential for correlating energy deposition with biological effects that are observed when living tissues are irradiated. Dose-response information provides the basis for radiation protection standards and risk assessment. Radiation interactions with living matter takes place on a microscopic scale, and the manifestation of damage may be evident at the cellular, multi-cellular, and even organ levels of biological organization. The relative biological effectiveness of ionization radiation is largely determined by the spatial distribution of energy deposition events within microscopic as well as macroscopic biological targets of interest. The spatial distribution of energy imparted is determined by the spatial distribution of radionuclides and properties of the emitted charged-particle radiation involved. The nonuniformity of energy deposition events in microscopic volumes, particularly from high linear energy transfer (LET) radiation, results in large variations in the amount of energy imparted to very small volumes or targets. Microdosimetry is the study of energy deposition events at the cellular level. Macrodosimetry is a term for conventional dose averaging at the tissue or organ level. In between is a level of dosimetry sometimes referred to as multi-cellular dosimetry. The distinction between these terms and their applications in assessment of dose from internally deposited radionuclides is described.

  19. 10 CFR 35.630 - Dosimetry equipment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Dosimetry equipment. 35.630 Section 35.630 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Photon Emitting Remote Afterloader Units, Teletherapy... American Association of Physicists in Medicine (AAPM). The calibration must have been performed within...

  20. 10 CFR 35.630 - Dosimetry equipment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Dosimetry equipment. 35.630 Section 35.630 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Photon Emitting Remote Afterloader Units, Teletherapy... American Association of Physicists in Medicine (AAPM). The calibration must have been performed within...

  1. 10 CFR 35.630 - Dosimetry equipment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Dosimetry equipment. 35.630 Section 35.630 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Photon Emitting Remote Afterloader Units, Teletherapy... American Association of Physicists in Medicine (AAPM). The calibration must have been performed within...

  2. 10 CFR 35.630 - Dosimetry equipment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Dosimetry equipment. 35.630 Section 35.630 Energy NUCLEAR REGULATORY COMMISSION MEDICAL USE OF BYPRODUCT MATERIAL Photon Emitting Remote Afterloader Units, Teletherapy... American Association of Physicists in Medicine (AAPM). The calibration must have been performed within...

  3. Patient-specific internal radionuclide dosimetry.

    PubMed

    Tsougos, Ioannis; Loudos, George; Georgoulias, Panagiotis; Theodorou, Kiki; Kappas, Constantin

    2010-02-01

    The development of patient-specific treatment planning systems is of outmost importance in the development of radionuclide dosimetry, taking into account that quantitative three-dimensional nuclear medical imaging can be used in this regard. At present, the established method for dosimetry is based on the measurement of the biokinetics by serial gamma-camera scans, followed by calculations of the administered activity and the residence times, resulting in the radiation-absorbed doses of critical organs. However, the quantification of the activity in different organs from planar data is hampered by inaccurate attenuation and scatter correction as well as because of background and organ overlay. In contrast, dosimetry based on quantitative three-dimensional data can be more accurate and allows an individualized approach, provided that all effects that degrade the quantitative content of the images have been corrected for. In addition, inhomogeneous organ accumulation of the radionuclide can be detected and possibly taken into account. The aim of this work is to provide adequate information on internal emitter dosimetry and a state-of-the-art review of the current methodology and future trends.

  4. Dosimetry of an Implantable 252 Californium Source

    SciTech Connect

    Oliver, G.D. Jr.

    2001-08-29

    The radiation dose from 252 Californium needles designed for use as a source of neutrons for radiotherapy has been measured. The dosimetry information presented in this paper will enable clinical studies of neutron radiotherapy with 252 Californium needles to be planned and begun.

  5. Protocol for emergency EPR dosimetry in fingernails

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is an increased need for after-the fact dosimetry because of the high risk of radiation exposures due to terrorism or accidents. In case of such an event, a method is needed to make measurements of dose in a large number of individuals rapidly and with sufficient accuracy to facilitate effect...

  6. Blood volume and red cell life span (M113), part C

    NASA Technical Reports Server (NTRS)

    Johnson, P. C., Jr.

    1973-01-01

    Prechamber, in-chamber, and postchamber blood samples taken from Skylab simulation crewmembers did not indicate significant shortening of the red cell life span during the mission. This does not suggest that the space simulation environment could not be associated with red cell enzyme changes. It does show that any changes in enzymes were not sufficiently great to significantly shorten red cell survival. There was no evidence of bone marrow erythropoetic suppression nor was there any evidence of increased red cell destruction.

  7. Skeletal dosimetry based on µCT images of trabecular bone: update and comparisons

    NASA Astrophysics Data System (ADS)

    Kramer, R.; Cassola, V. F.; Vieira, J. W.; Khoury, H. J.; de Oliveira Lira, C. A. B.; Robson Brown, K.

    2012-06-01

    Two skeletal dosimetry methods using µCT images of human bone have recently been developed: the paired-image radiation transport (PIRT) model introduced by researchers at the University of Florida (UF) in the US and the systematic-periodic cluster (SPC) method developed by researchers at the Federal University of Pernambuco in Brazil. Both methods use µCT images of trabecular bone (TB) to model spongiosa regions of human bones containing marrow cavities segmented into soft tissue volumes of active marrow (AM), trabecular inactive marrow and the bone endosteum (BE), which is a 50 µm thick layer of marrow on all TB surfaces and on cortical bone surfaces next to TB as well as inside the medullary cavities. With respect to the radiation absorbed dose, the AM and the BE are sensitive soft tissues for the induction of leukaemia and bone cancer, respectively. The two methods differ mainly with respect to the number of bone sites and the size of the µCT images used in Monte Carlo calculations and they apply different methods to simulate exposure from radiation sources located outside the skeleton. The PIRT method calculates dosimetric quantities in isolated human bones while the SPC method uses human bones embedded in the body of a phantom which contains all relevant organs and soft tissues. Consequently, the SPC method calculates absorbed dose to the AM and to the BE from particles emitted by radionuclides concentrated in organs or from radiation sources located outside the human body in one calculation step. In order to allow for similar calculations of AM and BE absorbed doses using the PIRT method, the so-called dose response functions (DRFs) have been developed based on absorbed fractions (AFs) of energy for electrons isotropically emitted in skeletal tissues. The DRFs can be used to transform the photon fluence in homogeneous spongiosa regions into absorbed dose to AM and BE. This paper will compare AM and BE AFs of energy from electrons emitted in skeletal

  8. Red Hill

    EPA Pesticide Factsheets

    Information about the Red Hill Bulk Fuel Storage Facility in Hawaii Administrative Order on Consent (AOC), an enforceable agreement of the Hawaii Department of Health, the Environmental Protection Agency, and the U.S. Navy -- Defense Logistics Agency.

  9. ELECTRON ABSORBED FRACTIONS IN AN IMAGE-BASED MICROSCOPIC SKELETAL DOSIMETRY MODEL OF CHINESE ADULT MALE.

    PubMed

    Gao, Shenshen; Ren, Li; Qiu, Rui; Wu, Zhen; Li, Chunyan; Li, Junli

    2017-01-10

    Based on the Chinese reference adult male voxel model, a set of microscopic skeletal models of Chinese adult male is constructed through the processes of computed tomography (CT) imaging, bone coring, micro-CT imaging, image segmentation, merging into macroscopic bone model and implementation in Geant4. At the step of image segmentation, a new bone endosteum (BE) segmentation method is realized by sampling. The set of model contains 32 spongiosa samples with voxel size of 19 μm cubes. The microscopic spongiosa bone data for Chinese adult male are provided. Electron absorbed fractions in red bone marrow (RBM) and BE are calculated. Source tissues include the bone marrow (red and yellow), trabecular bone (surfaces and volumes) and cortical bone (surfaces and volumes). Target tissues include RBM and BE. Electron energies range from 10 keV to 10 MeV. Additionally, comparison of the result with other investigations is provided.

  10. Dose Escalation and Dosimetry of First in Human Alpha Radioimmunotherapy with 212Pb-TCMC-trastuzumab

    PubMed Central

    Meredith, Ruby; Torgue, Julien; Shen, Sui; Fisher, Darrell R.; Banaga, Eileen; Bunch, Patty; Morgan, Desiree; Fan, Jinda; Straughn, J. Michael

    2015-01-01

    Our purpose was to study the safety, distribution, pharmacokinetics, immunogenicity and tumor response of intraperitoneal (IP) 212Pb-TCMC-trastuzumab (TCMC is S-2-(4-isothiocyantobenzl)-1, 4, 7, 10-tetraaza-1, 4, 7, 10=tetra (2-carbamoylmethl) cyclododecane) in patients with HER-2 expressing malignancy. Methods In a standard 3+3 Phase 1 design for dose escalation, 212Pb-TCMC-trastuzumab was delivered IP less than 4 hours after giving 4mg/kg IV trastuzumab to patients with peritoneal carcinomatosis who had failed standard therapies. Results Five dosage levels (7.4, 9.6, 12.6, 16.3, 21.1 MBq/m2) showed minimal toxicity at >1 year for the first group and >4 months for others. The lack of substantial toxicity was consistent with the dosimetry assessments (mean equivalent dose to marrow = 0.18 mSv/MBq). Radiation dosimetry assessment was performed using pharmacokinetics data obtained in the initial cohort (n=3). Limited redistribution of radioactivity out of the peritoneal cavity to circulating blood, which cleared via urinary excretion and no specific uptake in major organs was observed in 24 hours. Maximum serum concentration of the radiolabeled antibody was 22.9% at 24h (decay corrected to injection time) and 500 Bq/mL (decay corrected to collection time). Non-decay corrected cumulative urinary excretion was ≤6% in 24h (2.3 half lives). Dose rate measurements performed at 1m from the patient registered less than 5μSv/hr (using portable detectors) in the latest cohort, significantly less than what is normally observed using nuclear medicine imaging agents. Anti-drug antibody assays performed on serum from the first 4 cohorts were all negative. Conclusions Five dose levels of IP 212Pb-TCMC-trastuzumab treatment of patients with peritoneal carcinomatosis showed little agent related toxicity, consistent with the dosimetry calculations. PMID:25157044

  11. Patient-specific dosimetry in peptide receptor radionuclide therapy: a clinical review.

    PubMed

    Chalkia, M T; Stefanoyiannis, A P; Chatziioannou, S N; Round, W H; Efstathopoulos, E P; Nikiforidis, G C

    2015-03-01

    Neuroendocrine tumours (NETs) belong to a relatively rare class of neoplasms. Nonetheless, their prevalence has increased significantly during the last decades. Peptide receptor radionuclide therapy (PRRT) is a relatively new treatment approach for inoperable or metastasised NETs. The therapeutic effect is based on the binding of radiolabelled somatostatin analogue peptides with NETs' somatostatin receptors, resulting in internal irradiation of tumours. Pre-therapeutic patient-specific dosimetry is essential to ensure that a treatment course has high levels of safety and efficacy. This paper reviews the methods applied for PRRT dosimetry, as well as the dosimetric results presented in the literature. Focus is given on data concerning the therapeutic somatostatin analogue radiopeptides (111)In-[DTPA(0),D-Phe(1)]-octreotide ((111)In-DTPA-octreotide), (90)Y-[DOTA(0),Tyr(3)]-octreotide ((90)Y-DOTATOC) and (177)Lu-[DOTA(0),Tyr(3),Thr(8)]-octreotide ((177)Lu-DOTATATE). Following the Medical Internal Radiation Dose (MIRD) Committee formalism, dosimetric analysis demonstrates large interpatient variability in tumour and organ uptake, with kidneys and bone marrow being the critical organs. The results are dependent on the image acquisition and processing protocol, as well as the dosimetric imaging radiopharmaceutical.

  12. An automated voxelized dosimetry tool for radionuclide therapy based on serial quantitative SPECT/CT imaging

    SciTech Connect

    Jackson, Price A.; Kron, Tomas; Beauregard, Jean-Mathieu; Hofman, Michael S.; Hogg, Annette; Hicks, Rodney J.

    2013-11-15

    Purpose: To create an accurate map of the distribution of radiation dose deposition in healthy and target tissues during radionuclide therapy.Methods: Serial quantitative SPECT/CT images were acquired at 4, 24, and 72 h for 28 {sup 177}Lu-octreotate peptide receptor radionuclide therapy (PRRT) administrations in 17 patients with advanced neuroendocrine tumors. Deformable image registration was combined with an in-house programming algorithm to interpolate pharmacokinetic uptake and clearance at a voxel level. The resultant cumulated activity image series are comprised of values representing the total number of decays within each voxel's volume. For PRRT, cumulated activity was translated to absorbed dose based on Monte Carlo-determined voxel S-values at a combination of long and short ranges. These dosimetric image sets were compared for mean radiation absorbed dose to at-risk organs using a conventional MIRD protocol (OLINDA 1.1).Results: Absorbed dose values to solid organs (liver, kidneys, and spleen) were within 10% using both techniques. Dose estimates to marrow were greater using the voxelized protocol, attributed to the software incorporating crossfire effect from nearby tumor volumes.Conclusions: The technique presented offers an efficient, automated tool for PRRT dosimetry based on serial post-therapy imaging. Following retrospective analysis, this method of high-resolution dosimetry may allow physicians to prescribe activity based on required dose to tumor volume or radiation limits to healthy tissue in individual patients.

  13. Methotrexate and bone marrow metaphases.

    PubMed

    Cunningham, J J; Potter, A M; Watmore, A E; Winfield, D A

    1988-07-15

    The efficacy of a methotrexate (MTX) block/thymidine release synchronization technique has been assessed in bone marrow cultures from patients with acute nonlymphocytic leukemia and myelodysplasia. In contrast to cultures of stimulated lymphocytes from normal individuals, no improvement in mitotic index (MI) or metaphase quality could be detected using this technique. Demonstration of an unchanged level of division in bone marrow cultures in the presence of MTX suggests that the technique is unsuitable for synchronization purposes in this tissue. The influence of preincubation prior to MTX exposure and duration of exposure to colcemid on MI and metaphase quality have also been examined.

  14. Dosimetry of the Leksell gamma knife

    NASA Astrophysics Data System (ADS)

    Meltsner, Sheridan Griffin

    No accepted official protocol exists for the dosimetry of the Leksell Gamma KnifeRTM (GK) stereotactic radiosurgery device. Establishment of a dosimetry protocol has been complicated by the unique partial-hemisphere arrangement of 201 separate 60Co beams simultaneously focused on the treatment volume and by the rigid geometry of the GK unit itself. This paper proposes an air kerma based dosimetry protocol using an in-air or in-acrylic phantom measurement to determine the dose rate of fields collimated by the 18 mm helmet of a GK unit. A small-volume ionization chamber was used to make measurements at the physical isocenter of three GK units. The dose rate to water was determined using a modified version of the AAPM Task Group 21 protocol designed for use with 60Co-based teletherapy machines. This experimentally determined dose rate was compared to the treatment planning system (TPS) dose rate that is determined by the clinical medical physicist at the time of machine commissioning. The TPS dose rate is defined as dose rate to water at a depth of 8 cm. The dose rate to water for the 18 mm helmet determined using the air kerma based calculations presented here is consistently between 1.5% and 2.9% higher than the TPS dose rate. These air kerma based measurements allow GK dosimetry to be performed with an established dosimetry protocol and without complications arising from the use of and possible variations in solid phantom material. Measurements were made with the same chamber in a spherical acrylic phantom for comparison. This methodology will allow future development of calibration methods appropriate for the smaller fields of GK units to be compared to a well established standard. Multiple three-dimensional dosimetry methods were also used to capture the dose distribution of the entire field of the GK. These methods included radiosensitive gel, a novel three-dimensional radiochromic film phantom, and Monte Carlo modeling. These methods were also compared to the

  15. Neocytolysis: physiological down-regulator of red-cell mass

    NASA Technical Reports Server (NTRS)

    Alfrey, C. P.; Rice, L.; Udden, M. M.; Driscoll, T. B.

    1997-01-01

    It is usually considered that red-cell mass is controlled by erythropoietin-driven bone marrow red-cell production, and no physiological mechanisms can shorten survival of circulating red cells. In adapting to acute plethora in microgravity, astronauts' red-cell mass falls too rapidly to be explained by diminished red-cell production. Ferrokinetics show no early decline in erythropolesis, but red cells radiolabelled 12 days before launch survive normally. Selective destruction of the youngest circulating red cells-a process we call neocytolysis-is the only plausible explanation. A fall in erythropoietin below a threshold is likely to initiate neocytolysis, probably by influencing surface-adhesion molecules. Recognition of neocytolysis will require re-examination of the pathophysiology and treatment of several blood disorders, including the anaemia of renal disease.

  16. EANM Dosimetry Committee guidance document: good practice of clinical dosimetry reporting.

    PubMed

    Lassmann, M; Chiesa, C; Flux, G; Bardiès, M

    2011-01-01

    Many recent publications in nuclear medicine contain data on dosimetric findings for existing and new diagnostic and therapeutic agents. In many of these articles, however, a description of the methodology applied for dosimetry is lacking or important details are omitted. The intention of the EANM Dosimetry Committee is to guide the reader through a series of suggestions for reporting dosimetric approaches. The authors are aware of the large amount of data required to report the way a given clinical dosimetry procedure was implemented. Another aim of this guidance document is to provide comprehensive information for preparing and submitting publications and reports containing data on internal dosimetry. This guidance document also contains a checklist which could be useful for reviewers of manuscripts submitted to scientific journals or for grant applications. In addition, this document could be used to decide which data are useful for a documentation of dosimetry results in individual patient records. This may be of importance when the approval of a new radiopharmaceutical by official bodies such as EMA or FDA is envisaged.

  17. TU-F-201-00: Radiochromic Film Dosimetry Update

    SciTech Connect

    2015-06-15

    Since the introduction of radiochromic films (RCF) for radiation dosimetry, the scope of RCF dosimetry has expanded steadily to include many medical applications, such as radiation therapy and diagnostic radiology. The AAPM Task Group (TG) 55 published a report on the recommendations for RCF dosimetry in 1998. As the technology is advancing rapidly, and its routine clinical use is expanding, TG 235 has been formed to provide an update to TG-55 on radiochromic film dosimetry. RCF dosimetry applications in clinical radiotherapy have become even more widespread, expanding from primarily brachytherapy and radiosurgery applications, and gravitating towards (but not limited to) external beam therapy (photon, electron and protons), such as quality assurance for IMRT, VMAT, Tomotherapy, SRS/SRT, and SBRT. In addition, RCF applications now extend to measurements of radiation dose in particle beams and patients undergoing medical exams, especially fluoroscopically guided interventional procedures and CT. The densitometers/scanners used for RCF dosimetry have also evolved from the He-Ne laser scanner to CCD-based scanners, including roller-based scanner, light box-based digital camera, and flatbed color scanner. More recently, multichannel RCF dosimetry introduced a new paradigm for external beam dose QA for its high accuracy and efficiency. This course covers in detail the recent advancements in RCF dosimetry. Learning Objectives: Introduce the paradigm shift on multichannel film dosimetry Outline the procedures to achieve accurate dosimetry with a RCF dosimetry system Provide comprehensive guidelines on RCF dosimetry for various clinical applications One of the speakers has a research agreement from Ashland Inc., the manufacturer of Gafchromic film.

  18. Hanford External Dosimetry Technical Basis Manual PNL-MA-842

    SciTech Connect

    Rathbone, Bruce A.

    2005-02-25

    The Hanford External Dosimetry Technical Basis Manual PNL-MA-842 documents the design and implementation of the external dosimetry system used at Hanford. The manual describes the dosimeter design, processing protocols, dose calculation methodology, radiation fields encountered, dosimeter response characteristics, limitations of dosimeter design under field conditions, and makes recommendations for effective use of the dosimeters in the field. The manual describes the technical basis for the dosimetry system in a manner intended to help ensure defensibility of the dose of record at Hanford and to demonstrate compliance with 10 CFR 835, DOELAP, DOE-RL, ORP, PNSO, and Hanford contractor requirements. The dosimetry system is operated by PNNL’s Hanford External Dosimetry Program which provides dosimetry services to all Hanford contractors. The primary users of this manual are DOE and DOE contractors at Hanford using the dosimetry services of PNNL. Development and maintenance of this manual is funded directly by DOE and DOE contractors. Its contents have been reviewed and approved by DOE and DOE contractors at Hanford through the Hanford Personnel Dosimetry Advisory Committee which is chartered and chaired by DOE-RL and serves as means of coordinating dosimetry practices across contractors at Hanford. This manual was established in 1996. Since inception, it has been revised many times and maintained by PNNL as a controlled document with controlled distribution. Rev. 0 marks the first revision to be released through PNNL’s Electronic Records & Information Capture Architecture (ERICA) database.

  19. Neutron dosimetry using optically stimulated luminescence

    NASA Astrophysics Data System (ADS)

    Miller, S. D.; Eschbach, P. A.

    1991-06-01

    The addition of thermoluminescent (TL) materials within hydrogenous matrices to detect neutron induced proton recoils for radiation dosimetry is a well known concept. Previous attempts to implement this technique have met with limited success, primarily due to the high temperatures required for TL readout and the low melting temperatures of hydrogen-rich plastics. Research in recent years PNL has produced a new Optically Stimulated Luminescence (OSL) technique known as the Cooled Optically Stimulated Luminescence (COSL) that offers, for the first time, the capability of performing extremely sensitive radiation dosimetry at low temperatures. In addition to its extreme sensitivity, the COSL technique offers multiple readout capability, limited fading in a one year period, and the capability of analyzing single grains within a hydrogenous matrix.

  20. Criticality accident dosimetry with ESR spectroscopy.

    PubMed

    d'Errico, F; Fattibene, P; Onori, S; Pantaloni, M

    1996-01-01

    The suitability of the ESR alanine and sugar detectors for criticality accident dosimetry was experimentally investigated during an intercomparison of dosimetry techniques. Tests were performed irradiating detectors both free-in-air and on-phantom during controlled critcality excursions at the SILENE reactor in Valduc, France. Several grays of absorbed dose were imparted in neutron gamma-ray fields of various relative intensities and spectral distributions. Analysed results confirmed the potential of these systems which can immediately provide an acute dose assessment with an average underestimate of 30%in the various fields. This performance allows for the screening of severely exposed individuals and meets the IAEA recommendations on the early estimate of accident absorbed doses.

  1. Passive particle dosimetry. [silver halide crystal growth

    NASA Technical Reports Server (NTRS)

    Childs, C. B.

    1977-01-01

    Present methods of dosimetry are reviewed with emphasis on the processes using silver chloride crystals for ionizing particle dosimetry. Differences between the ability of various crystals to record ionizing particle paths are directly related to impurities in the range of a few ppm (parts per million). To understand the roles of these impurities in the process, a method for consistent production of high purity silver chloride, and silver bromide was developed which yields silver halides with detectable impurity content less than 1 ppm. This high purity silver chloride was used in growing crystals with controlled doping. Crystals were grown by both the Czochalski method and the Bridgman method, and the Bridgman grown crystals were used for the experiments discussed. The distribution coefficients of ten divalent cations were determined for the Bridgman crystals. The best dosimeters were made with silver chloride crystals containing 5 to 10 ppm of lead; other impurities tested did not produce proper dosimeters.

  2. Patient-specific dosimetry in radionuclide therapy.

    PubMed

    Lyra, Maria; Lagopati, Nefeli; Charalambatou, Paraskevi; Vamvakas, Ioannis

    2011-09-01

    This study presents an attempt to compare individualised palliative treatment absorbed doses, by planar images data and Monte Carlo simulation, in two in vivo treatment cases, one of bone metastases and the other of liver lesions. Medical Internal Radiation Dose schema was employed to estimate the absorbed doses. Radiopharmaceutical volume distributions and absorbed doses in the lesions as well as in critical organs were also calculated by Monte Carlo simulation. Individualised planar data calculations remain the method of choice in internal dosimetry in nuclear medicine, but with the disadvantage of attenuation and scatter corrections lack and organ overlay. The overall error is about 7 % for planar data calculations compared with that using Monte Carlo simulation. Patient-specific three-dimensional dosimetric calculations using single-photon emission computed tomography with a parallel computed tomography study is proposed as an accurate internal dosimetry with the additional use of dose-volume histograms, which express dose distributions in cases with obvious inhomogeneity.

  3. Trigeminal neuralgia treatment dosimetry of the Cyberknife

    SciTech Connect

    Ho, Anthony; Lo, Anthony T.; Dieterich, Sonja; Soltys, Scott G.; Gibbs, Iris C.; Chang, Steve G.; Adler, John R.

    2012-04-01

    There are 2 Cyberknife units at Stanford University. The robot of 1 Cyberknife is positioned on the patient's right, whereas the second is on the patient's left. The present study examines whether there is any difference in dosimetry when we are treating patients with trigeminal neuralgia when the target is on the right side or the left side of the patient. In addition, we also study whether Monte Carlo dose calculation has any effect on the dosimetry. We concluded that the clinical and dosimetric outcomes of CyberKnife treatment for trigeminal neuralgia are independent of the robot position. Monte Carlo calculation algorithm may be useful in deriving the dose necessary for trigeminal neuralgia treatments.

  4. Absolute and relative dosimetry for ELIMED

    NASA Astrophysics Data System (ADS)

    Cirrone, G. A. P.; Cuttone, G.; Candiano, G.; Carpinelli, M.; Leonora, E.; Lo Presti, D.; Musumarra, A.; Pisciotta, P.; Raffaele, L.; Randazzo, N.; Romano, F.; Schillaci, F.; Scuderi, V.; Tramontana, A.; Cirio, R.; Marchetto, F.; Sacchi, R.; Giordanengo, S.; Monaco, V.

    2013-07-01

    The definition of detectors, methods and procedures for the absolute and relative dosimetry of laser-driven proton beams is a crucial step toward the clinical use of this new kind of beams. Hence, one of the ELIMED task, will be the definition of procedures aiming to obtain an absolute dose measure at the end of the transport beamline with an accuracy as close as possible to the one required for clinical applications (i.e. of the order of 5% or less). Relative dosimetry procedures must be established, as well: they are necessary in order to determine and verify the beam dose distributions and to monitor the beam fluence and the energetic spectra during irradiations. Radiochromic films, CR39, Faraday Cup, Secondary Emission Monitor (SEM) and transmission ionization chamber will be considered, designed and studied in order to perform a fully dosimetric characterization of the ELIMED proton beam.

  5. Advances in personnel neutron dosimetry: part 3

    SciTech Connect

    Vallario, E.J.; Faust, L.G.

    1983-09-01

    DOE-sponsored evaluation and upgrading of personnel neutron dosimetry includes a review of new devices involving unique concepts: resonance ionization spectroscopy and organic semiconductor detectors. Resonance ionization spectroscopy uses a laser to detect atoms released by neutron interactions, while organic semiconductors contain large amounts of hydrogen. Although these and other research and evaluation projects reviewed in the first two articles appear promising, there is much more research needed, such as finding a chemically stable organic semiconductor that will be suitable.

  6. Permethrin Exposure Dosimetry: Biomarkers and Modifiable Factors

    DTIC Science & Technology

    2016-08-01

    the effect of body weight/BMI and total energy expenditure on permethrin absorption and dose, as determined by measurement of urinary biomarkers...Data collection for Study 2 is in progress. 15. SUBJECT TERMS Permethrin, biomarkers, military, dose, exposure dosimetry, military, energy expenditure...body weight/BMI and total energy expenditure on permethrin absorption and dose, as determined by measurement of urinary biomarkers (3PBA and cis- and

  7. Bayesian Methods for Radiation Detection and Dosimetry

    SciTech Connect

    Peter G. Groer

    2002-09-29

    We performed work in three areas: radiation detection, external and internal radiation dosimetry. In radiation detection we developed Bayesian techniques to estimate the net activity of high and low activity radioactive samples. These techniques have the advantage that the remaining uncertainty about the net activity is described by probability densities. Graphs of the densities show the uncertainty in pictorial form. Figure 1 below demonstrates this point. We applied stochastic processes for a method to obtain Bayesian estimates of 222Rn-daughter products from observed counting rates. In external radiation dosimetry we studied and developed Bayesian methods to estimate radiation doses to an individual with radiation induced chromosome aberrations. We analyzed chromosome aberrations after exposure to gammas and neutrons and developed a method for dose-estimation after criticality accidents. The research in internal radiation dosimetry focused on parameter estimation for compartmental models from observed compartmental activities. From the estimated probability densities of the model parameters we were able to derive the densities for compartmental activities for a two compartment catenary model at different times. We also calculated the average activities and their standard deviation for a simple two compartment model.

  8. Hanford Internal Dosimetry Project manual. Revision 1

    SciTech Connect

    Carbaugh, E.H.; Bihl, D.E.; MacLellan, J.A.; Long, M.P.

    1994-07-01

    This document describes the Hanford Internal Dosimetry Project, as it is administered by Pacific Northwest Laboratory (PNL) in support of the US Department of Energy and its Hanford contractors. Project services include administrating the bioassay monitoring program, evaluating and documenting assessment of potential intakes and internal dose, ensuring that analytical laboratories conform to requirements, selecting and applying appropriate models and procedures for evaluating radionuclide deposition and the resulting dose, and technically guiding and supporting Hanford contractors in matters regarding internal dosimetry. Specific chapters deal with the following subjects: practices of the project, including interpretation of applicable DOE Orders, regulations, and guidance into criteria for assessment, documentation, and reporting of doses; assessment of internal dose, including summary explanations of when and how assessments are performed; recording and reporting practices for internal dose; selection of workers for bioassay monitoring and establishment of type and frequency of bioassay measurements; capability and scheduling of bioassay monitoring services; recommended dosimetry response to potential internal exposure incidents; quality control and quality assurance provisions of the program.

  9. Reconstructive dosimetry for cutaneous radiation syndrome

    PubMed Central

    Lima, C.M.A.; Lima, A.R.; Degenhardt, Ä.L.; Valverde, N.J.; Da Silva, F.C.A.

    2015-01-01

    According to the International Atomic Energy Agency (IAEA), a relatively significant number of radiological accidents have occurred in recent years mainly because of the practices referred to as potentially high-risk activities, such as radiotherapy, large irradiators and industrial radiography, especially in gammagraphy assays. In some instances, severe injuries have occurred in exposed persons due to high radiation doses. In industrial radiography, 80 cases involving a total of 120 radiation workers, 110 members of the public including 12 deaths have been recorded up to 2014. Radiological accidents in industrial practices in Brazil have mainly resulted in development of cutaneous radiation syndrome (CRS) in hands and fingers. Brazilian data include 5 serious cases related to industrial gammagraphy, affecting 7 radiation workers and 19 members of the public; however, none of them were fatal. Some methods of reconstructive dosimetry have been used to estimate the radiation dose to assist in prescribing medical treatment. The type and development of cutaneous manifestations in the exposed areas of a person is the first achievable gross dose estimation. This review article presents the state-of-the-art reconstructive dosimetry methods enabling estimation of local radiation doses and provides guidelines for medical handling of the exposed individuals. The review also presents the Chilean and Brazilian radiological accident cases to highlight the importance of reconstructive dosimetry. PMID:26445332

  10. In vivo dosimetry in external beam radiotherapy

    SciTech Connect

    Mijnheer, Ben; Beddar, Sam; Izewska, Joanna; Reft, Chester

    2013-07-15

    In vivo dosimetry (IVD) is in use in external beam radiotherapy (EBRT) to detect major errors, to assess clinically relevant differences between planned and delivered dose, to record dose received by individual patients, and to fulfill legal requirements. After discussing briefly the main characteristics of the most commonly applied IVD systems, the clinical experience of IVD during EBRT will be summarized. Advancement of the traditional aspects of in vivo dosimetry as well as the development of currently available and newly emerging noninterventional technologies are required for large-scale implementation of IVD in EBRT. These new technologies include the development of electronic portal imaging devices for 2D and 3D patient dosimetry during advanced treatment techniques, such as IMRT and VMAT, and the use of IVD in proton and ion radiotherapy by measuring the decay of radiation-induced radionuclides. In the final analysis, we will show in this Vision 20/20 paper that in addition to regulatory compliance and reimbursement issues, the rationale for in vivo measurements is to provide an accurate and independent verification of the overall treatment procedure. It will enable the identification of potential errors in dose calculation, data transfer, dose delivery, patient setup, and changes in patient anatomy. It is the authors' opinion that all treatments with curative intent should be verified through in vivo dose measurements in combination with pretreatment checks.

  11. Static magnetic field therapy: dosimetry considerations.

    PubMed

    Colbert, Agatha P; Markov, Marko S; Souder, James S

    2008-06-01

    The widespread use of static magnetic field (SMF) therapy as a self-care physical intervention has led to the conduct of numerous randomized controlled trials (RCTs). A recent systematic review of SMF trials for pain reduction concluded that the evidence does not support the use of permanent magnets for pain relief. We argue that this conclusion is unwarranted if the SMF dosage was inadequate or inappropriate for the clinical condition treated. The purpose of this communication is to (1) provide a rationale and an explanation for each of 10 essential SMF dosing parameters that should be considered when conducting trials of SMF therapy, and (2) advocate for the conduct of Phase I studies to optimize SMF dosimetry for each condition prior to implementing a large-scale RCT. A previous critical review of SMF dosimetry in 56 clinical studies found that reporting SMF dosages in a majority of those studies was of such poor quality that the magnetic field exposure at the target tissue could not be characterized. Without knowing what magnetic field actually reached the target, it is impossible to judge dosage adequacy. In order to quantify SMF exposure at the site of pathology (target tissue/s), that site must be clearly named; the distance of the permanent magnet surface from the target must be delineated; the physical parameters of the applied permanent magnet must be described; and the dosing regimen must be precisely reported. If the SMF dosimetry is inadequate, any inferences drawn from reported negative findings are questionable.

  12. Bone and bone marrow: the same organ.

    PubMed

    Del Fattore, Andrea; Capannolo, Marta; Rucci, Nadia

    2010-11-01

    Interplays between bone and bone marrow are not limited to merely anatomic and histological connections, but include a tight functional correlation. Bone marrow resides within the medullary cavity of the bones and the process of hematopoiesis is regulated, at least in part, by bone cells. Moreover, osteoclasts and osteoblasts derive from precursors of hematopoietic and mesenchymal origin, respectively, both residing within the bone marrow. Alterations in one of these components typically cause impairment in the other, so diseases of the bone marrow compartment often affect the bone and vice versa. All these findings could make us to speculate that bone and bone marrow are not two separate districts, but can be considered as the two elements of the same unique functional unit, the bone-bone marrow organ. Here we will describe histological and functional interplays between bone and bone marrow, and will illustrate some diseases in which this tight correlation is evident.

  13. Parentage testing implications of male fertility after allogeneic bone marrow transplantation.

    PubMed

    Lipton, J H; Marshall, W H; Waye, J S

    1999-01-01

    Fertility is expected to be reduced after the extensive chemotherapy and/or radiotherapy that is needed for conditioning prior to bone marrow transplantation. However, a male patient can be fertile, and in very rare situations such as reported here, this may confuse subsequent paternity testing. The patient, initially excluded as the biological father by red cell types but not by HLA, was subsequently included after the history of his previous marrow transplant was revealed, a review of the HLA results and further RFLP testing on buccal mucosal cells. This case points to the need for good history taking before performing paternity testing.

  14. National Marrow Donor Program. HLA Typing for Bone Marrow Transplantation

    DTIC Science & Technology

    2014-11-30

    event. 3. Immunogenetic Studies: Increase understanding of the immunologic factors important in HSC transplantation. 4. Clinical Research... Immunology , and Transplantation DaSH Data Standards Hackathon DC Donor Center National Marrow Donor Program® N00014-13-1-0039 HLA Typing for Bone...Management Strategy ImmPort Immunology Database and Analysis Portal IND Investigational New Drug IND Improvised Nuclear Device IPR Immunobiology Project

  15. Dosimetry tools and techniques for IMRT.

    PubMed

    Low, Daniel A; Moran, Jean M; Dempsey, James F; Dong, Lei; Oldham, Mark

    2011-03-01

    Intensity modulated radiation therapy (IMRT) poses a number of challenges for properly measuring commissioning data and quality assurance (QA) radiation dose distributions. This report provides a comprehensive overview of how dosimeters, phantoms, and dose distribution analysis techniques should be used to support the commissioning and quality assurance requirements of an IMRT program. The proper applications of each dosimeter are described along with the limitations of each system. Point detectors, arrays, film, and electronic portal imagers are discussed with respect to their proper use, along with potential applications of 3D dosimetry. Regardless of the IMRT technique utilized, some situations require the use of multiple detectors for the acquisition of accurate commissioning data. The overall goal of this task group report is to provide a document that aids the physicist in the proper selection and use of the dosimetry tools available for IMRT QA and to provide a resource for physicists that describes dosimetry measurement techniques for purposes of IMRT commissioning and measurement-based characterization or verification of IMRT treatment plans. This report is not intended to provide a comprehensive review of commissioning and QA procedures for IMRT. Instead, this report focuses on the aspects of metrology, particularly the practical aspects of measurements that are unique to IMRT. The metrology of IMRT concerns the application of measurement instruments and their suitability, calibration, and quality control of measurements. Each of the dosimetry measurement tools has limitations that need to be considered when incorporating them into a commissioning process or a comprehensive QA program. For example, routine quality assurance procedures require the use of robust field dosimetry systems. These often exhibit limitations with respect to spatial resolution or energy response and need to themselves be commissioned against more established dosimeters. A chain of

  16. Immune transfer studies in canine allogeneic marrow graft donor-recipient pairs

    SciTech Connect

    Grosse-Wilde, H.; Krumbacher, K.; Schuening, F.D.; Doxiadis, I.; Mahmoud, H.K.; Emde, C.; Schmidt-Weinmar, A.; Schaefer, U.W.

    1986-07-01

    Transfer of immunity occurring with bone marrow grafting was studied using the dog as a preclinical model. Allogeneic bone marrow transplantation (BMT) was performed between DLA-identical beagle litter-mates. The donors were immunized with tetanus toxoid (TT) or sheep red blood cells (SRBC), and their humoral response was monitored by hemagglutination. The recipients of bone marrow from TT-immunized donors showed a marked increase of antibody titer one week posttransplantation, while in the recipients of marrow from SRBC immunized donors the antibody titers were considerably lower. Within the following 60 days the antibody titers in both groups diminished gradually to pregrafting levels. Control experiments in which cell-free plasma from donors immunized with TT and SRBC respectively was transfused indicated that the initial rise of specific antibody titers after marrow grafting is likely to be due to a passive transfer of humoral immunity. A single challenge of these marrow graft recipients with the respective antigen 15-18 weeks posttransplantation led to a secondary type of humoral immune response. It could be demonstrated that transfer of memory against TT or SRBC was independent from the actual antibody titer and the time of vaccination of the donor. One dog was immunized with TT after serving as marrow donor. When the donor had shown an antibody response, a peripheral blood leukocytes (PBL) transfusion was given to his chimera. Subsequent challenge of the latter resulted in a secondary type of specific antibody response. This indicates that specific cellular-bound immunological memory can be transferred after BMT from the donor to his allogeneic bone marrow chimera by transfusion of peripheral blood leukocytes. The data may be of importance in clinical BMT to protect patients during the phase of reduced immune reactivity by transfer of memory cells.

  17. Primary bone marrow oedema syndromes.

    PubMed

    Patel, Sanjeev

    2014-05-01

    MRI scanning in patients with rheumatological conditions often shows bone marrow oedema, which can be secondary to inflammatory, degenerative, infective or malignant conditions but can also be primary. The latter condition is of uncertain aetiology and it is also uncertain whether it represents a stage in the progression to osteonecrosis in some patients. Patients with primary bone marrow oedema usually have lower limb pain, commonly the hip, knee, ankle or feet. The diagnosis is one of exclusion with the presence of typical MRI findings. Treatment is usually conservative and includes analgesics and staying off the affected limb. The natural history is that of gradual resolution of symptoms over a number of months. Evidence for medical treatment is limited, but open-label studies suggest bisphosphonates may help in the resolution of pain and improve radiological findings. Surgical decompression is usually used as a last resort.

  18. Evaluation of the uncertainty in an EBT3 film dosimetry system utilizing net optical density.

    PubMed

    León Marroquin, Elsa Y; Herrera González, José A; Camacho López, Miguel A; Villarreal Barajas, José E; García-Garduño, Olivia A

    2016-09-08

    Radiochromic film has become an important tool to verify dose distributions for intensity-modulated radiotherapy (IMRT) and quality assurance (QA) procedures. A new radiochromic film model, EBT3, has recently become available, whose composition and thickness of the sensitive layer are the same as those of previous EBT2 films. However, a matte polyester layer was added to EBT3 to prevent the formation of Newton's rings. Furthermore, the symmetrical design of EBT3 allows the user to eliminate side-orientation dependence. This film and the flatbed scanner, Epson Perfection V750, form a dosimetry system whose intrinsic characteristics were studied in this work. In addition, uncertainties associated with these intrinsic characteristics and the total uncertainty of the dosimetry system were determined. The analysis of the response of the radiochromic film (net optical density) and the fitting of the experimental data to a potential function yielded an uncertainty of 2.6%, 4.3%, and 4.1% for the red, green, and blue channels, respectively. In this work, the dosimetry system presents an uncertainty in resolving the dose of 1.8% for doses greater than 0.8 Gy and less than 6 Gy for red channel. The films irradiated between 0 and 120 Gy show differences in the response when scanned in portrait or landscape mode; less uncertainty was found when using the portrait mode. The response of the film depended on the position on the bed of the scanner, contributing an uncertainty of 2% for the red, 3% for the green, and 4.5% for the blue when placing the film around the center of the bed of scanner. Furthermore, the uniformity and reproducibility radiochromic film and reproducibility of the response of the scanner contribute less than 1% to the overall uncertainty in dose. Finally, the total dose uncertainty was 3.2%, 4.9%, and 5.2% for red, green, and blue channels, respectively. The above uncertainty values were obtained by mini-mizing the contribution to the total dose uncertainty

  19. Evaluation of the uncertainty in an EBT3 film dosimetry system utilizing net optical density.

    PubMed

    Marroquin, Elsa Y León; Herrera González, José A; Camacho López, Miguel A; Barajas, José E Villarreal; García-Garduño, Olivia A

    2016-09-01

    Radiochromic film has become an important tool to verify dose distributions for intensity-modulated radiotherapy (IMRT) and quality assurance (QA) procedures. A new radiochromic film model, EBT3, has recently become available, whose composition and thickness of the sensitive layer are the same as those of previous EBT2 films. However, a matte polyester layer was added to EBT3 to prevent the formation of Newton's rings. Furthermore, the symmetrical design of EBT3 allows the user to eliminate side-orientation dependence. This film and the flatbed scanner, Epson Perfection V750, form a dosimetry system whose intrinsic characteristics were studied in this work. In addition, uncertainties associated with these intrinsic characteristics and the total uncertainty of the dosimetry system were determined. The analysis of the response of the radiochromic film (net optical density) and the fitting of the experimental data to a potential function yielded an uncertainty of 2.6%, 4.3%, and 4.1% for the red, green, and blue channels, respectively. In this work, the dosimetry system presents an uncertainty in resolving the dose of 1.8% for doses greater than 0.8 Gy and less than 6 Gy for red channel. The films irradiated between 0 and 120 Gy show differences in the response when scanned in portrait or landscape mode; less uncertainty was found when using the portrait mode. The response of the film depended on the position on the bed of the scanner, contributing an uncertainty of 2% for the red, 3% for the green, and 4.5% for the blue when placing the film around the center of the bed of scanner. Furthermore, the uniformity and reproducibility radiochromic film and reproducibility of the response of the scanner contribute less than 1% to the overall uncertainty in dose. Finally, the total dose uncertainty was 3.2%, 4.9%, and 5.2% for red, green, and blue channels, respectively. The above uncertainty values were obtained by minimizing the contribution to the total dose uncertainty

  20. Baby marrow: ethicists and privacy.

    PubMed Central

    Zucker, A

    1992-01-01

    A family had a child in large part to use its marrow in the hopes of saving the life of an older child afflicted with leukaemia. Public response from medical ethicists was negative. This paper argues that what the family did was not clearly wrong and that the ethicists should not have made public pronouncements calling the morals of the family into question. PMID:1404278

  1. Neutron dosimetry and radiation damage calculations for HFBR

    SciTech Connect

    Greenwood, L.R.; Ratner, R.T.

    1998-03-01

    Neutron dosimetry measurements have been conducted for various positions of the High Flux Beam Reactor (HFBR) at Brookhaven National Laboratory (BNL) in order to measure the neutron flux and energy spectra. Neutron dosimetry results and radiation damage calculations are presented for positions V10, V14, and V15.

  2. Student Perceptions of an Online Medical Dosimetry Program

    ERIC Educational Resources Information Center

    Lenards, Nishele D.

    2007-01-01

    The University of Wisconsin--La Crosse offers the first web-based medical dosimetry program in the nation. There is no data to research a program of this type. This research consisted of the evaluation of other distance education programs including health profession programs in addition to face-to-face medical dosimetry programs. There was need to…

  3. [Instrumental radiofrequency electromagnetic radiation dosimetry: general principals and modern methodology].

    PubMed

    Perov, S Iu; Kudriashov, Iu B; Rubtsova, N B

    2012-01-01

    The modern experimental radiofrequency electromagnetic field dosimetry approach has been considered. The main principles of specific absorbed rate measurement are analyzed for electromagnetic field biological effect assessment. The general methodology of specific absorbed rate automated dosimetry system applied to establish the compliance of radiation sources with the safety standard requirements (maximum permissible levels and base restrictions) is described.

  4. Basic principles in the radiation dosimetry of nuclear medicine.

    PubMed

    Stabin, Michael; Xu, Xie George

    2014-05-01

    The basic principles of the use of radiation dosimetry in nuclear medicine are reviewed. The basic structure of the main mathematical equations are given and formal dosimetry systems are discussed. An extensive overview of the history and current status of anthropomorphic models (phantoms) is given. The sources and magnitudes of uncertainties in calculated internal dose estimates are reviewed.

  5. EURADOS strategic research agenda: vision for dosimetry of ionising radiation

    PubMed Central

    Rühm, W.; Fantuzzi, E.; Harrison, R.; Schuhmacher, H.; Vanhavere, F.; Alves, J.; Bottollier Depois, J. F.; Fattibene, P.; Knežević, Ž.; Lopez, M. A.; Mayer, S.; Miljanić, S.; Neumaier, S.; Olko, P.; Stadtmann, H.; Tanner, R.; Woda, C.

    2016-01-01

    Since autumn 2012, the European Radiation Dosimetry Group (EURADOS) has been developing its Strategic Research Agenda (SRA), which is intended to contribute to the identification of future research needs in radiation dosimetry in Europe. The present article summarises—based on input from EURADOS Working Groups (WGs) and Voting Members—five visions in dosimetry and defines key issues in dosimetry research that are considered important for the next decades. The five visions include scientific developments required towards (a) updated fundamental dose concepts and quantities, (b) improved radiation risk estimates deduced from epidemiological cohorts, (c) efficient dose assessment for radiological emergencies, (d) integrated personalised dosimetry in medical applications and (e) improved radiation protection of workers and the public. The SRA of EURADOS will be used as a guideline for future activities of the EURADOS WGs. A detailed version of the SRA can be downloaded as a EURADOS report from the EURADOS website (www.eurados.org). PMID:25752758

  6. Sandia National Laboratories Internal Dosimetry Technical Basis Manual (Rev 4)

    SciTech Connect

    Goke, Sarah Hayes; Elliott, Nathan Ryan

    2014-09-01

    The Sandia National Laboratories’ Internal Dosimetry Technical Basis Manual is intended to provide extended technical discussion and justification of the internal dosimetry program at SNL. It serves to record the approach to evaluating internal doses from radiobioassay data, and where appropriate, from workplace monitoring data per the Department of Energy Internal Dosimetry Program Guide DOE G 441.1C. The discussion contained herein is directed primarily to current and future SNL internal dosimetrists. In an effort to conserve space in the TBM and avoid duplication, it contains numerous references providing an entry point into the internal dosimetry literature relevant to this program. The TBM is not intended to act as a policy or procedure statement, but will supplement the information normally found in procedures or policy documents. The internal dosimetry program outlined in this manual is intended to meet the requirements of Federal Rule 10CFR835 for monitoring the workplace and for assessing internal radiation doses to workers.

  7. American Red Cross

    MedlinePlus

    ... Espanol Local Red Cross ( ) Change Chapter Edit Zip Code Edit Zip Code Shop the Red Cross Store Toggle Navigation Menu ... Espanol Local Red Cross ( ) Change Chapter Edit Zip Code Edit Zip Code Shop the Red Cross Store ...

  8. Evaluation of iron status: zinc protoporphyrin vis-a-vis bone marrow iron stores.

    PubMed

    Das, Sheila; Philip, Kandathil Joseph

    2008-01-01

    Zinc protoporphyrin (ZPP) in the red cells is an indicator of iron status in the bone marrow (BM) and can be easily measured by Protofluor-Z Hematofluorometer from Helena Laboratories. It is well known that bone marrow iron is a gold standard for the diagnosis of iron deficiency anemia (IDA) even in the pre-latent phase. Hence, it was considered pertinent to evaluate the diagnostic utility of ZPP in comparison with bone marrow iron stores. 107 random BM were selected over a period of 2(1/2) years; in each case, RBC indices where recorded along with ZPP and Perls' Prussian blue reaction for BM iron stores. The specificity and sensitivity were found to be 77.8% and sensitivity 69.8%, respectively. However, the sensitivity increased up to 96.2% when Hb, RBC indices and ZPP were considered for the diagnosis of IDA.

  9. Improving neutron dosimetry using bubble detector technology

    SciTech Connect

    Buckner, M.A.

    1993-02-01

    Providing accurate neutron dosimetry for a variety of neutron energy spectra is a formidable task for any dosimetry system. Unless something is known about the neutron spectrum prior to processing the dosimeter, the calculated dose may vary greatly from that actually encountered; that is until now. The entrance of bubble detector technology into the field of neutron dosimetry has eliminated the necessity of having an a priori knowledge of the neutron energy spectra. Recently, a new approach in measuring personnel neutron dose equivalent was developed at Oak Ridge National Laboratory. By using bubble detectors in combination with current thermoluminescent dosimeters (TLDs) as a Combination Personnel Neutron Dosimeter (CPND), not only is it possible to provide accurate dose equivalent results, but a simple four-interval neutron energy spectrum is obtained as well. The components of the CPND are a Harshaw albedo TLD and two bubble detectors with theoretical energy thresholds of 100 key and 1500 keV. Presented are (1) a synoptic history surrounding emergence of bubble detector technology, (2) a brief overview of the current theory on mechanisms of interaction, (3) the data and analysis process involved in refining the response functions, (4) performance evaluation of the original CPND and a reevaluation of the same data under the modified method, (5) the procedure used to determine the reference values of component fluence and dose equivalent for field assessment, (6) analysis of the after-modification results, (7) a critique of some currently held assumptions, offering some alternative explanations, and (8) thoughts concerning potential applications and directions for future research.

  10. Model selection for radiochromic film dosimetry.

    PubMed

    Méndez, I

    2015-05-21

    The purpose of this study was to find the most accurate model for radiochromic film dosimetry by comparing different channel independent perturbation models. A model selection approach based on (algorithmic) information theory was followed, and the results were validated using gamma-index analysis on a set of benchmark test cases. Several questions were addressed: (a) whether incorporating the information of the non-irradiated film, by scanning prior to irradiation, improves the results; (b) whether lateral corrections are necessary when using multichannel models; (c) whether multichannel dosimetry produces better results than single-channel dosimetry; (d) which multichannel perturbation model provides more accurate film doses. It was found that scanning prior to irradiation and applying lateral corrections improved the accuracy of the results. For some perturbation models, increasing the number of color channels did not result in more accurate film doses. Employing Truncated Normal perturbations was found to provide better results than using Micke-Mayer perturbation models. Among the models being compared, the triple-channel model with Truncated Normal perturbations, net optical density as the response and subject to the application of lateral corrections was found to be the most accurate model. The scope of this study was circumscribed by the limits under which the models were tested. In this study, the films were irradiated with megavoltage radiotherapy beams, with doses from about 20-600 cGy, entire (8 inch  × 10 inch) films were scanned, the functional form of the sensitometric curves was a polynomial and the different lots were calibrated using the plane-based method.

  11. In vivo light dosimetry for pleural PDT

    NASA Astrophysics Data System (ADS)

    Dimofte, Andreea; Zhu, Timothy C.; Finlay, Jarod C.; Culligan, Melissa; Edmonds, Christine E.; Friedberg, Joseph S.; Cengel, Keith; Hahn, Stephen M.

    2009-02-01

    In-vivo light Dosimetry for patients undergoing photodynamic therapy (PDT) is one of the important dosimetry quantities critical for predicting PDT outcome. This study examines the light fluence (rate) delivered to patients undergoing pleural PDT as a function of treatment time, treatment volume and surface area, and its accuracy as a function of the calibration accuracies of each isotropic detector and the calibration integrating sphere. The patients studied here were enrolled in Phase II clinical trial of Photofrin-mediated PDT for the treatment of non-small cell lung cancer with pleural effusion. The ages of the patients studied varied from 34 to 69 year old. All patients were administered 2mg per kg body weight Photoprin 24 hours before the surgery. Patients undergoing photodynamic therapy (PDT) are treated with laser light with a light fluence of 60 J/cm^2 at 630nm. Fluence rate (mW/cm^2) and cumulative fluence (J/cm^2) was monitored at 7 different sites during the entire light treatment delivery. Isotropic detectors were used for in-vivo light dosimetry. The anisotropy of each isotropic detector was found to be within 30%. The mean fluence rate delivery varied from 37.84 to 94.05 mW/cm^2 and treatment time varied from 1762 to 5232s. We have established a correlation between the treatment time and the treatment volume. The results are discussed using an integrating sphere theory and the measured tissue optical properties. The result can be used as a clinical guideline for future pleural PDT treatment.

  12. The next decade in external dosimetry

    SciTech Connect

    Griffith, R.V.

    1986-10-01

    As the radiation protection community moves through the last half of the '80s and into the next decade, we can expect the requirements for external dosimetry to become increasingly more restrictive and demanding. As in other health protection fields, growing regulatory and legal pressures, together with a natural evolution in philosophy, require the health physicist to display an increasing degree of accountability, rigor, and professionalism. The good news is that, for the most part, the technology necessary to solve many of the problems will be available or not far behind. This paper describes anticipated technology. 66 refs., 10 figs.

  13. Proton minibeam radiation therapy: Experimental dosimetry evaluation

    SciTech Connect

    Peucelle, C.; Martínez-Rovira, I.; Prezado, Y.; Nauraye, C.; Patriarca, A.; Hierso, E.; Fournier-Bidoz, N.

    2015-12-15

    Purpose: Proton minibeam radiation therapy (pMBRT) is a new radiotherapy (RT) approach that allies the inherent physical advantages of protons with the normal tissue preservation observed when irradiated with submillimetric spatially fractionated beams. This dosimetry work aims at demonstrating the feasibility of the technical implementation of pMBRT. This has been performed at the Institut Curie - Proton Therapy Center in Orsay. Methods: Proton minibeams (400 and 700 μm-width) were generated by means of a brass multislit collimator. Center-to-center distances between consecutive beams of 3200 and 3500 μm, respectively, were employed. The (passive scattered) beam energy was 100 MeV corresponding to a range of 7.7 cm water equivalent. Absolute dosimetry was performed with a thimble ionization chamber (IBA CC13) in a water tank. Relative dosimetry was carried out irradiating radiochromic films interspersed in a IBA RW3 slab phantom. Depth dose curves and lateral profiles at different depths were evaluated. Peak-to-valley dose ratios (PVDR), beam widths, and output factors were also assessed as a function of depth. Results: A pattern of peaks and valleys was maintained in the transverse direction with PVDR values decreasing as a function of depth until 6.7 cm. From that depth, the transverse dose profiles became homogeneous due to multiple Coulomb scattering. Peak-to-valley dose ratio values extended from 8.2 ± 0.5 at the phantom surface to 1.08 ± 0.06 at the Bragg peak. This was the first time that dosimetry in such small proton field sizes was performed. Despite the challenge, a complete set of dosimetric data needed to guide the first biological experiments was achieved. Conclusions: pMBRT is a novel strategy in order to reduce the side effects of RT. This works provides the experimental proof of concept of this new RT method: clinical proton beams might allow depositing a (high) uniform dose in a brain tumor located in the center of the brain (7.5 cm depth

  14. Characteristics of in vivo radiotherapy dosimetry.

    PubMed

    Edwards, C R; Mountford, P J

    2009-11-01

    The recent discussion and debate about the use of in vivo dosimetry as a routine component of the radiotherapy treatment process has not included the limitations introduced by the physical characteristics of the detectors. Although a robust calibration procedure will ensure acceptable uncertainties in the measurements of tumour dose, further work is required to confirm the accuracy of critical organ measurements with a diode or a thermoluminescent dosemeter outside the main field owing to limitations caused by a non-uniform X-ray energy response of the detector, differences between the X-ray energy spectrum inside and outside the main field, and contaminating electrons.

  15. Neutron dosimetry of the Little Boy device

    SciTech Connect

    Pederson, R.A.; Plassmann, E.A.

    1984-01-01

    Neutron dose rates at several angular locations and at distances out to 0.5 mile have been measured during critical operation of the Little Boy replica. We used modified remmetes and thermoluminescent dosimetry techniques for the measurements. The present status of our analysis is presented including estimates of the neutron-dose-relaxation length in air and the variation of the neutron-to-gamma-ray dose ratio with distance from the replica. These results are preliminary and are subject to detector calibration measurements.

  16. USF/Russian dosimetry on STS-57

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The major purpose of this experiment was to conduct an international comparison of passive dosimetry methods in space. Two APD's were flown in the charged particle directional spectrometer (CPDS)/tissue equivalent proportional counter (TEPC) locker on the space shuttle during the STS-57 mission. Due to placement, the shielding and radiation environment of the APD's were nearly the same and the dosimeters distributed in the two boxes can be considered equally exposed. The dosimeter types included plastic nuclear track detectors (PNTD's), thermoluminescent detectors (TLD), nuclear emulsions, and thermal/resonance neutron detectors (TRND's). The USF dosimeters included PNTD's, TLD's, and TRND's, while the Russian dosimeters included PNTD's, TLD's, and nuclear emulsions.

  17. Cure of murine thalassemia by bone marrow transplantation without eradication of endogenous stem cells

    SciTech Connect

    Wagemaker, G.; Visser, T.P.; van Bekkum, D.W.

    1986-09-01

    alpha-Thalassemic heterozygous (Hbath/+) mice were used to investigate the possible selective advantage of transplanted normal (+/+) hemopoietic cells. Without conditioning by total-body irradiation (TBI), infusion of large numbers of normal bone marrow cells failed to correct the thalassemic peripheral blood phenotype. Since the recipients' stem cells are normal with respect to number and differentiation capacity, it was thought that the transplanted stem cells were not able to lodge, or that they were not stimulated to proliferate. Therefore, a nonlethal dose of TBI was given to temporarily reduce endogenous stem cell numbers and hemopoiesis. TBI doses of 2 or 3 Gy followed by infusion of normal bone marrow cells proved to be effective in replacing the thalassemic red cells by normal red cells, whereas a dose of 1 Gy was ineffective. It is concluded that cure of thalassemia by bone marrow transplantation does not necessarily require eradication of thalassemic stem cells. Consequently, the objectives of conditioning regimens for bone marrow transplantation of thalassemic patients (and possibly other nonmalignant hemopoietic disorders) should be reconsidered.

  18. Dosimetry of ionising radiation in modern radiation oncology

    NASA Astrophysics Data System (ADS)

    Kron, Tomas; Lehmann, Joerg; Greer, Peter B.

    2016-07-01

    Dosimetry of ionising radiation is a well-established and mature branch of physical sciences with many applications in medicine and biology. In particular radiotherapy relies on dosimetry for optimisation of cancer treatment and avoidance of severe toxicity for patients. Several novel developments in radiotherapy have introduced new challenges for dosimetry with small and dynamically changing radiation fields being central to many of these applications such as stereotactic ablative body radiotherapy and intensity modulated radiation therapy. There is also an increasing awareness of low doses given to structures not in the target region and the associated risk of secondary cancer induction. Here accurate dosimetry is important not only for treatment optimisation but also for the generation of data that can inform radiation protection approaches in the future. The article introduces some of the challenges and highlights the interdependence of dosimetric calculations and measurements. Dosimetric concepts are explored in the context of six application fields: reference dosimetry, small fields, low dose out of field, in vivo dosimetry, brachytherapy and auditing of radiotherapy practice. Recent developments of dosimeters that can be used for these purposes are discussed using spatial resolution and number of dimensions for measurement as sorting criteria. While dosimetry is ever evolving to address the needs of advancing applications of radiation in medicine two fundamental issues remain: the accuracy of the measurement from a scientific perspective and the importance to link the measurement to a clinically relevant question. This review aims to provide an update on both of these.

  19. Dosimetry of inhaled radon and thoron progeny

    SciTech Connect

    James, A.C.

    1994-06-01

    This chapter reviews recent developments in modeling doses received by lung tissues, with particular emphasis on application of ICRP`s new dosimetric model of the respiratory tract for extrapolating to other environments the established risks from exposure to radon progeny in underground mines. Factors discussed include: (1) the influence of physical characteristics of radon progeny aerosols on dose per unit exposure, e.g., the unattached fraction, and the activity-size distributions of clustered and attached progeny; (2) the dependence of dose on breathing rate, and on the exposed subject (man, woman or child); (3) the variability of dose per unit exposure in a home when exposure is expressed in terms of potential {alpha} energy or radon gas concentration; (4) the comparative dosimetry of thoron progeny; and (5) the effects of air-cleaning on lung dose. Also discussed is the apparent discrepancy between lung cancer risk estimates derived purely from dosimetry and the lung cancer incidence observed in the epidemiological studies of radon-exposed underground miners. Application of ICRP`s recommended risk factors appears to overestimate radon lung-cancer risk for miners by a factor of three. ``Normalization`` of the calculated effective dose is therefore needed, at least for {alpha} dose from radon and thoron progeny, in order to obtain a realistic estimate of lung cancer risk.

  20. Dosimetry of two new interstitial brachytherapy sources

    NASA Astrophysics Data System (ADS)

    Saidi, Pooneh; Sadeghi, Mahdi

    2011-01-01

    With increased demand for low 103Pd (palladium) seed sources, to treat prostate and eye cancers, new sources have been designed and introduced. This article presents the two new palladium brachytherapy sources, IR03-103Pd and IR04-103Pd that have been developed at Nuclear Science and Technology Research Institute. The dosimetry parameters such as the dose rate constant Λ, the radial dose function g(r), and the anisotropy function F(r,θ), around the sources have been characterized using Version 5 Monte Carlo radiation transport code in accordance with the update AAPM Task Group No. 43 report (TG-43U1). The results indicated the dose rate constant of 0.689±0.02 and 0.667±0.02 cGy h-1 U-1 for the IR03-103Pd and IR04-103Pd sources respectively, which are in acceptable agreement with other commercial seeds. The calculated results were compared with published results for those of other source manufacturers. However, they show an acceptable dose distribution, using for clinical applications is pending experimental dosimetry.

  1. Eleventh DOE workshop on personnel neutron dosimetry

    SciTech Connect

    Not Available

    1991-12-31

    Since its formation, the Office of Health (EH-40) has stressed the importance of the exchange of information related to and improvements in neutron dosimetry. This Workshop was the eleventh in the series sponsored by the Department of Energy (DOE). It provided a forum for operational personnel at DOE facilities to discuss current issues related to neutron dosimetry and for leading investigators in the field to discuss promising approaches for future research. A total of 26 papers were presented including the keynote address by Dr. Warren K. Sinclair, who spoke on, ``The 1990 Recommendations of the ICRP and their Biological Background.`` The first several papers discussed difficulties in measuring neutrons of different energies and ways of compensating or deriving correction factors at individual facilities. Presentations were also given by the US Navy and Air Force. Current research in neutron dosimeter development was the subject of the largest number of papers. These included a number on the development of neutron spectrometers. Selected papers were processed separately for inclusion in the Energy Science and Technology Database.

  2. PDT dose dosimetry for pleural photodynamic therapy

    PubMed Central

    Sharikova, Anna V.; Finlay, Jarod C.; Liang, Xing; Zhu, Timothy C.

    2015-01-01

    PDT dose is the product of the photosensitizer concentration and the light fluence in target tissue. Although existing systems are capable of measuring the light fluence in vivo, the concurrent measurement of photosensitizer in the treated tissue so far has been lacking. We have developed and tested a new method to simultaneously acquire light dosimetry and photosensitizer fluorescence data via the same isotropic detector, employing treatment light as the excitation source. A dichroic beamsplitter is used to split light from the isotropic detector into two fibers, one for light dosimetry, the other, after the 665 nm treatment light is removed by a band-stop filter, to a spectrometer for fluorescence detection. The light fluence varies significantly during treatment because of the source movement. The fluorescence signal is normalized by the light fluence measured at treatment wavelength. We have shown that the absolute photosensitizer concentration can be obtained by an optical properties correction factor and linear spectral fitting. Tissue optical properties are determined using an absorption spectroscopy probe immediately before PDT at the same sites. This novel method allows accurate real-time determination of delivered PDT dose using existing isotropic detectors, and may lead to a considerable improvement of PDT treatment quality compared to the currently employed systems. Preliminary data in patient studies is presented. PMID:25999645

  3. Acoustic images of gel dosimetry phantoms

    NASA Astrophysics Data System (ADS)

    Vieira, Silvio L.; Baggio, André; Kinnick, Randall R.; Fatemi, M.; Carneiro, Antonio Adilton O.

    2010-01-01

    This work presents Vibro-acoustography (VA) as a tool to visualize absorbed dose in a polymer gel dosimetry phantom. VA relies on the mechanical excitation introduced by the acoustic radiation force of focused modulated ultrasound in a small region of the object. A hydrophone or microphone is used to measure the sound emitted from the object in response to the excitation, and by using the amplitude or phase of this signal, an image of the object can be generated. To study the phenomena of dose distribution in a gel dosimetry phantom, continuous wave (CW), tone burst and multi-frequency VA were used to image this phantom. The phantom was designed using 'MAGIC' gel polymer with addition of glass microspheres at 2% w/w having an average diameter range between 40-75 μm. The gel was irradiated using conventional 10 MeV X-rays from a linear accelerator. The field size in the surface of the phantom was 1.0×1.0 cm2 and a source-surface distance (SSD) of 100 cm. The irradiated volume corresponds to an approximately 8.0 cm3, where a dose of 50 gray was delivered to the gel. Polymer gel dosimeters are sensitive to radiation-induced chemical changes that occur in the irradiated polymer. VA images of the gel dosimeter showed the irradiate area. It is concluded that VA imaging has potential to visualize dose distribution in a polymer gel dosimeter.

  4. Dosimetry of radium-223 and progeny

    SciTech Connect

    Fisher, D.R.; Sgouros, G.

    1999-01-01

    Radium-223 is a short-lived (11.4 d) alpha emitter with potential applications in radioimmunotherapy of cancer. Radium-223 can be complexed and linked to protein delivery molecules for specific tumor-cell targeting. It decays through a cascade of short-lived alpha- and beta-emitting daughters with emission of about 28 MeV of energy through complete decay. The first three alpha particles are essentially instantaneous. Photons associated with Ra-223 and progeny provide the means for tumor and normal-organ imaging and dosimetry. Two beta particles provide additional therapeutic value. Radium-223 may be produced economically and in sufficient amounts for widescale application. Many aspects of the chemistry of carrier-free isotope preparation, complexation, and linkage to the antibody have been developed and are being tested. The radiation dosimetry of a Ra-223-labeled antibody shows favorable tumor to normal tissue dose ratios for therapy. The 11.4-d half-life of Ra-223 allows sufficient time for immunoconjugate preparation, administration, and tumor localization by carrier antibodies before significant radiological decay takes place. If 0.01 percent of a 37 MBq (1 mCi) injection deposits in a one gram tumor mass, and if the activity is retained with a typical effective half-time (75 h), the absorbed dose will be 163 mGy MBq{sup {minus}1} (600 rad mCi{sup {minus}1}) administered. 49 refs., 5 figs., 2 tabs.

  5. Internal dosimetry verification and validation database.

    PubMed

    Miller, G; Bertelli, L; Little, T; Guilmette, R A

    2007-01-01

    Simulated-data internal dosimetry cases for use in intercomparison exercises or as a software verification and validation tool have been published on the internet (www.lanl.gov/bayesian/software Bayesian software package II). A user may validate their internal dosimetry code or method using this simulated bioassay data. Or, the user may choose to try out the Los Alamos National Laboratory codes ID and UF, which are also supplied. A Poisson-lognormal model of data uncertainty is assumed. A collection of different possible models for each nuclide (e.g. solubility types and particle sizes) are used. For example, for 238Pu, 14 different biokinetic models or types (8 inhalation, 4 wound and 2 ingestion) are assumed. Simulated data are generated for all the assumed biokinetic models, both for incidents, where the time of intake is known, and for non-incidents, where it is not. For the dose calculations, the route of intake, but not the biokinetic model, is considered to be known. The object is to correctly calculate the known true dose from simulated data covering a period of time. A 'correct' result has been defined in two ways: (1) that the credible limits of the calculated dose include the correct dose and (2) that the calculated dose is within a factor of 2 of the correct dose.

  6. Radiotherapy dosimetry using a commercial OSL system

    SciTech Connect

    Viamonte, A.; Rosa, L. A. R. da; Buckley, L. A.; Cherpak, A.; Cygler, J. E.

    2008-04-15

    A commercial optically stimulated luminescence (OSL) system developed for radiation protection dosimetry by Landauer, Inc., the InLight microStar reader, was tested for dosimetry procedures in radiotherapy. The system uses carbon-doped aluminum oxide, Al{sub 2}O{sub 3}:C, as a radiation detector material. Using this OSL system, a percent depth dose curve for {sup 60}Co gamma radiation was measured in solid water. Field size and SSD dependences of the detector response were also evaluated. The dose response relationship was investigated between 25 and 400 cGy. The decay of the response with time following irradiation and the energy dependence of the Al{sub 2}O{sub 3}:C OSL detectors were also measured. The results obtained using OSL dosimeters show good agreement with ionization chamber and diode measurements carried out under the same conditions. Reproducibility studies show that the response of the OSL system to repeated exposures is 2.5% (1sd), indicating a real possibility of applying the Landauer OSL commercial system for radiotherapy dosimetric procedures.

  7. Hanford External Dosimetry Technical Basis Manual PNL-MA-842

    SciTech Connect

    Rathbone, Bruce A.

    2009-08-28

    The Hanford External Dosimetry Technical Basis Manual PNL-MA-842 documents the design and implementation of the external dosimetry system used at Hanford. The manual describes the dosimeter design, processing protocols, dose calculation methodology, radiation fields encountered, dosimeter response characteristics, limitations of dosimeter design under field conditions, and makes recommendations for effective use of the dosimeters in the field. The manual describes the technical basis for the dosimetry system in a manner intended to help ensure defensibility of the dose of record at Hanford and to demonstrate compliance with 10 CFR 835, DOELAP, DOE-RL, ORP, PNSO, and Hanford contractor requirements. The dosimetry system is operated by PNNL’s Hanford External Dosimetry Program (HEDP) which provides dosimetry services to all Hanford contractors. The primary users of this manual are DOE and DOE contractors at Hanford using the dosimetry services of PNNL. Development and maintenance of this manual is funded directly by DOE and DOE contractors. Its contents have been reviewed and approved by DOE and DOE contractors at Hanford through the Hanford Personnel Dosimetry Advisory Committee (HPDAC) which is chartered and chaired by DOE-RL and serves as means of coordinating dosimetry practices across contractors at Hanford. This manual was established in 1996. Since inception, it has been revised many times and maintained by PNNL as a controlled document with controlled distribution. The first revision to be released through PNNL’s Electronic Records & Information Capture Architecture (ERICA) database was designated Revision 0. Revision numbers that are whole numbers reflect major revisions typically involving changes to all chapters in the document. Revision numbers that include a decimal fraction reflect minor revisions, usually restricted to selected chapters or selected pages in the document.

  8. Monoclonal gammopathy-associated pure red cell aplasia.

    PubMed

    Korde, Neha; Zhang, Yong; Loeliger, Kelsey; Poon, Andrea; Simakova, Olga; Zingone, Adriana; Costello, Rene; Childs, Richard; Noel, Pierre; Silver, Samuel; Kwok, Mary; Mo, Clifton; Young, Neal; Landgren, Ola; Sloand, Elaine; Maric, Irina

    2016-06-01

    Pure red cell aplasia (PRCA) is a rare disorder characterized by inhibition of erythroid precursors in the bone marrow and normochromic, normocytic anaemia with reticulocytopenia. Among 51 PRCA patients, we identified 12 (24%) patients having monoclonal gammopathy, monoclonal gammopathy of undetermined significance or smouldering multiple myeloma, with presence of monoclonal protein or abnormal serum free light chains and atypical bone marrow features of clonal plasmacytosis, hypercellularity and fibrosis. Thus far, three patients treated with anti-myeloma based therapeutics have responded with reticulocyte recovery and clinical transfusion independence, suggesting plasma cells play a key role in the pathogenesis of this specific monoclonal gammopathy-associated PRCA.

  9. [Computational radiofrequency electromagnetic field dosimetry in evaluation of biological effects].

    PubMed

    Perov, S Iu; Kudryashov, Iu B; Rubtsova, N B

    2012-01-01

    Given growing computational resources, radiofrequency electromagnetic field dosimetry is becoming more vital in the study of biological effects of non-ionizing electromagnetic radiation. The study analyzes numerical methods which are used in theoretical dosimetry to assess the exposure level and specific absorption rate distribution. The advances of theoretical dosimetry are shown. Advantages and disadvantages of different methods are analyzed in respect to electromagnetic field biological effects. The finite-difference time-domain method was implemented in detail; also evaluated were possible uncertainties of complex biological structure simulation for bioelectromagnetic investigations.

  10. Dosimetry of Auger emitters: Physical and phenomenological approaches

    SciTech Connect

    Sastry, K.S.R.; Howell, R.W.; Rao, D.V.; Mylavarapu, V.B.; Kassis, A.I.; Adelstein, S.J.; Wright, H.A.; Hamm, R.N.; Turner, J.E.

    1987-01-01

    Recent radiobiological studies have demonstrated that Auger cascades can cause severe biological damage contrary to expectations based on conventional dosimetry. Several determinants govern these effects, including the nature of the Auger electron spectrum; localized energy deposition; cellular geometry; chemical form of the carrier; cellular localization, concentration, and subcellular distribution of the radionuclide. Conventional dosimetry is inadequate in that these considerations are ignored. Our results provide the basis for biophysical approaches toward subcellular dosimetry of Auger emitters in vitro and in vivo. 12 refs., 7 figs., 2 tabs.

  11. Build-up material requirements in clinical dosimetry during total body irradiation treatments

    PubMed Central

    Butson, Martin; Pope, Dane; Haque, Mamoon; Chen, Tom; Song, Guangli; Whitaker, May

    2016-01-01

    Total body irradiation (TBI) treatments are mainly used in a preparative regimen for hematopoietic stem cell (or bone marrow) transplantation. Our standard clinical regimen is a 12 Gy/6 fraction bi-daily technique using 6MV X-rays at a large extended source to surface distance (SSD). This work investigates and quantifies the dose build-up characteristics and thus the requirements for bolus used for in vivo dosimetry for TBI applications. Percentage dose build-up characteristics of photon beams have been investigated at large extended SSDs using ionization chambers and Gafchromic film. Open field measurements at different field sizes and with differing scatter conditions such as the introduction of standard Perspex scattering plates at different distances to the measurement point were made in an effort to determine the required bolus/build-up material required for accurate determination of applied dose. Percentage surface dose values measured for open fields at 300 cm SSD were found to range from 20% up to 65.5% for fields 5 cm × 5 cm to 40 cm × 40 cm, respectively. With the introduction of 1 cm Perspex scattering plates used in TBI treatments, the surface dose values increased up to 83–90% (93–97% at 1 mm depth), depending on the position of the Perspex scattering plate compared to the measurement point. Our work showed that at least 5 mm water equivalent bolus/scatter material should be placed over the EBT3 film for accurate dose assessment for TBI treatments. Results also show that a small but measurable decrease in measured dose occurred with 5 mm water equivalent thick bolus material of areas '3 cm2. As such, we recommend that 3 cm × 3 cm × 5 mm bolus build-up is the smallest size that should be placed over EBT3 Gafchromic film when used for accurate in vivo dosimetry for TBI applications. PMID:27217628

  12. Inhomogeneity in optical properties of rat brain: a study for LLLT dosimetry

    NASA Astrophysics Data System (ADS)

    Sousa, Marcelo V. P.; Prates, Renato; Kato, Ilka T.; Sabino, Caetano P.; Yoshimura, Tania M.; Suzuki, Luis C.; Magalhães, Ana C.; Yoshimura, Elisabeth M.; Ribeiro, Martha S.

    2013-03-01

    Over the last few years, low-level light therapy (LLLT) has shown an incredible suitability for a wide range of applications for central nervous system (CNS) related diseases. In this therapeutic modality light dosimetry is extremely critical so the study of light propagation through the CNS organs is of great importance. To better understand how light intensity is delivered to the most relevant neural sites we evaluated optical transmission through slices of rat brain point by point. We experimented red (λ = 660 nm) and near infrared (λ = 808 nm) diode laser light analyzing the light penetration and distribution in the whole brain. A fresh Wistar rat (Rattus novergicus) brain was cut in sagittal slices and illuminated with a broad light beam. A high-resolution digital camera was employed to acquire data of transmitted light. Spatial profiles of the light transmitted through the sample were obtained from the images. Peaks and valleys in the profiles show sites where light was less or more attenuated. The peak intensities provide information about total attenuation and the peak widths are correlated to the scattering coefficient at that individual portion of the sample. The outcomes of this study provide remarkable information for LLLT dose-dependent studies involving CNS and highlight the importance of LLLT dosimetry in CNS organs for large range of applications in animal and human diseases.

  13. Solar particle events observed at Mars: dosimetry measurements and model calculations

    NASA Astrophysics Data System (ADS)

    Cleghorn, T.; Saganti, P.; Zeitlin, C.; Cucinotta, F.

    The first solar particle events from a Martian orbit are observed with the MARIE (Martian Radiation Environment Experiment) on the 2001 Mars Odyssey space -craft that is currently in orbit and collecting the mapping data of the red planet. These solar particle events observed at Mars during March and April 2002, are correlated with the GOES-8 and ACE satellite data from the same time period at Earth orbits. Dosimetry measurements for the Mars orbit from the period of March 13t h through April 29t h . Particle count rate and the corresponding dose rate enhancements were observed on March 16t h through 20t h and on April 22n d corresponding to solar particle events that were observed at Earth orbit on March 16t h through 21s t and beginning on April 21s t respectively. The model calculations with the HZETRN (High Z=atomic number and high Energy Transport) code estimated the background GCR (Galactic Cosmic Rays) dose rates. The dose rates observed by the MARIE instrument are within 10% of the model calculations. Dosimetry measurements and model calculation will be presented.

  14. Kinetics of erythrogenesis after bone marrow transplantation.

    PubMed

    Lazarus, H M; Chahine, A; Lacerna, K; Wamble, A; Iaffaldano, C; Straight, M; Rabinovitch, A; Schimenti, K J; Jacobberger, J

    1992-04-01

    To determine the kinetics of bone marrow erythrogenesis after bone marrow transplantation, the authors counted reticulocytes (by blood smear and flow cytometry) and compared those data with neutrophil and platelet recovery in 23 consecutive bone marrow transplant patients. The earliest indication of marrow recovery after allogeneic and autologous bone marrow transplantation was defined as the second increasing cell count after the lowest recorded count, provided that the trend continued upward. Recovery of marrow function was detected earlier in 10 of 23 patients using reticulocyte counts than by either neutrophil or platelet count alone. Specifically, in 8 of these 10 patients, recovery of erythropoiesis was determined earlier by flow cytometric examination than by the blood smear method. On the other hand, combining the data using the earliest value of platelet, neutrophil, and reticulocyte counts indicated that the mean day of recovery in our patient population was determined to be 12.1 +/- 4 days after marrow infusion. In patients undergoing autologous and allogeneic bone marrow transplantation, serial neutrophil and reticulocyte count determinations are complementary in early clinical detection of successful engraftment.

  15. Inherited Bone Marrow Failure Syndromes (IBMFS)

    Cancer.gov

    The NCI IBMFS Cohort Study consists of affected individuals and their immediate families in North America who have an inherited bone marrow failure syndrome (IBMFS)-either one that has been specifically identified and defined, or bone marrow failure that appears to be inherited but has not yet been clearly identified as having a genetic basis.

  16. Androgen, Estrogen and the Bone Marrow Microenvironment

    DTIC Science & Technology

    2009-12-01

    SUPPLEMENTARY NOTES 14. ABSTRACT We have accomplished the following: 1) Characterized androgen responsive genes in mouse bone marrow (BM) via...castration (androgen ablation) and estrogen stimulation. 2) Measurements of testosterone, dihydrotestosterone and of genes that regulate the local... gene expression in the bone marrow. In males, the main source of estrogen is through conversion of androgen by aromatase. We postulate that gene

  17. Comparison of vidar dosimetry advantage pro and epson perfection V700 scanner in densitometry of radiochomic EBT2 film in measurement of high dose gradient

    NASA Astrophysics Data System (ADS)

    Bura, W.; Tangboonduangjit, P.; Damrongkijudom, N.

    2016-03-01

    Nowadays the radiochromic film is widely used to obtain dose distribution in two dimensions with high spatial resolution, less energy dependence and near tissue equivalent. It can be a commissioning tool to verify high dose gradient of dose distribution for IMRT and VMAT techniques. However, the film scanner could affect the accuracy of dose distribution if lack of precaution. In this study, the comparison between Epson perfection V700 and Vidar Dosimetry Pro Advantage (RED) is evaluated in terms of the capability to verify the 2D dose distribution for conventional and VMAT techniques. The Gafchromic® EBT2 films were read from two types of scanners (Epson perfection V700 and Vidar Dosimetry Pro Advantage) for volumetric modulated radiation therapy (VMAT) dosimetry. The software for analyzing the results of Epson perfection V700 and Vidar Dosimetry Pro Advantage are SNC Patient software and Omnipro’ IMRT software, respectively. Comparisons between measured and calculated dose distributions are reported as %passing rate and the gamma index for tolerance parameters of 3% and 3mm. The study found that the %passing rate obtained from Vidar scanner and Epson V700 scanner compared with Eclipse treatment planning system is more than 98% with the criteria of (3%/3mm).

  18. Practical IMRT QA dosimetry using Gafchromic film: a quick start guide.

    PubMed

    Bennie, Nick; Metcalfe, Peter

    2016-06-01

    This work outlines a method for using Gafchromic film for dosimetry purposes, by scanning it with currently available commercial scanners. The scanners used were: Epson V800, Epson V700, Epson V37 series, specifically a V370 and a Canon multi-function office printer/scanner. The Epson scanners have 16 bit RGB resolution, the Canon has 8 bit RGB (Red Green Blue) resolution, and the V800 and V700 allow scanning in transmission mode. The V700 uses an Epson White Cold Cathode Florescent Lamp; the recently released V800 uses an Epson light emitting diode (LED) light source, while the V37 series uses a reflective mode and the Epson LED light source. The Epson V37 series scanners are designed for non-professional use so the cost has been kept at a low "entry level" point, so they would be a suitable option for a department wanting to use Gafchromic film or with limited needs that did not justify a more sophisticated and expensive unit. Note that the V800 or V700 scanners are not expensive in context, costing approximately the same as a 25 sheet box of Gafchromic film. The Canon was included to demonstrate that a scanner with 8 bit RGB resolution can be used for dosimetry. These general multi-function units are available in most departments, and they would allow Gafchromic film to be evaluated as a dosimetry tool without a significant investment. Furthermore, they are generally capable of scanning large format film (425 × 350 mm) in one part. Although this is not necessary for dosimetry, it is often useful for machine QA, where dividing the film into two parts to ensure accurate measurements is not practical. Moreover, this analytical method uses software that is freely or commonly available, particularly the image processing package ImageJ. Note ImageJ v1.48 was the version used. The results demonstrate that this method used with the scanners evaluated is a practical method of using Gafchromic film as a dosimeter for IMRT QA.

  19. Permanent Breast Seed Implant Dosimetry Quality Assurance

    SciTech Connect

    Keller, Brian M.; Ravi, Ananth; Sankreacha, Raxa; Pignol, Jean-Philippe

    2012-05-01

    Purpose: A permanent breast seed implant is a novel method of accelerated partial breast irradiation for women with early-stage breast cancer. This article presents pre- and post-implant dosimetric data, relates these data to clinical outcomes, and makes recommendations for those interested in starting a program. Methods and Materials: A total of 95 consecutive patients were accrued into one of three clinical trials after breast-conserving surgery: a Phase I/II trial (67 patients with infiltrating ductal carcinoma); a Phase II registry trial (25 patients with infiltrating ductal carcinoma); or a multi-center Phase II trial for patients with ductal carcinoma in situ (3 patients). Contouring of the planning target volume (PTV) was done on a Pinnacle workstation and dosimetry calculations, including dose-volume histograms, were done using a Variseed planning computer. Results: The mean pre-implant PTV coverage for the V{sub 90}, V{sub 100}, V{sub 150}, and V{sub 200} were as follows: 98.8% {+-} 1.2% (range, 94.5-100%); 97.3% {+-} 2.1% (range, 90.3-99.9%), 68.8% {+-} 14.3% (range, 32.7-91.5%); and 27.8% {+-} 8.6% (range, 15.1-62.3%). The effect of seed motion was characterized by post-implant dosimetry performed immediately after the implantation (same day) and at 2 months after the implantation. The mean V{sub 100} changed from 85.6% to 88.4% (p = 0.004) and the mean V{sub 200} changed from 36.2% to 48.3% (p < 0.001). Skin toxicity was associated with maximum skin dose (p = 0.014). Conclusions: Preplanning dosimetry should aim for a V{sub 90} of approximately 100%, a V{sub 100} between 95% and 100%, and a V{sub 200} between 20% and 30%, as these numbers are associated with no local recurrences to date and good patient tolerance. In general, the target volume coverage improved over the duration of the seed therapy. The maximum skin dose, defined as the average dose over the hottest 1 Multiplication-Sign 1-cm{sup 2} surface area, should be limited to 90% of the

  20. Albedo neutron dosimetry in Germany: regulations and performance.

    PubMed

    Luszik-Bhadra, M; Zimbal, A; Busch, F; Eichelberger, A; Engelhardt, J; Figel, M; Frasch, G; Günther, K; Jordan, M; Martini, E; Haninger, T; Rimpler, A; Seifert, R

    2014-12-01

    Personal neutron dosimetry has been performed in Germany using albedo dosemeters for >20 y. This paper describes the main principles, the national standards, regulations and recommendations, the quality management and the overall performance, giving some examples.

  1. Gamma-ray dosimetry measurements of the Little Boy replica

    SciTech Connect

    Plassmann, E.A.; Pederson, R.A.

    1984-01-01

    We present the current status of our gamma-ray dosimetry results for the Little Boy replica. Both Geiger-Mueller and thermoluminescent detectors were used in the measurements. Future work is needed to test assumptions made in data analysis.

  2. Proceedings of the third conference on radiation protection and dosimetry

    SciTech Connect

    Swaja, R.E.; Sims, C.S.; Casson, W.H.

    1991-10-01

    The Third Conference on Radiation Protection and Dosimetry was held during October 21--24, 1991, at the Sheraton Plaza Hotel in Orlando, Florida. This meeting was designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection, and providing them with sufficient information to evaluate their programs. To meet these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection was prepared. General topics considered in the technical session included external dosimetry, internal dosimetry, instruments, accident dosimetry, regulations and standards, research advances, and applied program experience. In addition, special sessions were held to afford attendees the opportunity to make short presentations of recent work or to discuss topics of general interest. Individual reports are processed separately on the database.

  3. Retrospective dosimetry analyses of reactor vessel cladding samples

    SciTech Connect

    Greenwood, L. R.; Soderquist, C. Z.; Fero, A. H.

    2011-07-01

    Reactor pressure vessel cladding samples for Ringhals Units 3 and 4 in Sweden were analyzed using retrospective reactor dosimetry techniques. The objective was to provide the best estimates of the neutron fluence for comparison with neutron transport calculations. A total of 51 stainless steel samples consisting of chips weighing approximately 100 to 200 mg were removed from selected locations around the pressure vessel and were sent to Pacific Northwest National Laboratory for analysis. The samples were fully characterized and analyzed for radioactive isotopes, with special interest in the presence of Nb-93m. The RPV cladding retrospective dosimetry results will be combined with a re-evaluation of the surveillance capsule dosimetry and with ex-vessel neutron dosimetry results to form a comprehensive 3D comparison of measurements to calculations performed with 3D deterministic transport code. (authors)

  4. Software for evaluation of EPR-dosimetry performance.

    PubMed

    Shishkina, E A; Timofeev, Yu S; Ivanov, D V

    2014-06-01

    Electron paramagnetic resonance (EPR) with tooth enamel is a method extensively used for retrospective external dosimetry. Different research groups apply different equipment, sample preparation procedures and spectrum processing algorithms for EPR dosimetry. A uniform algorithm for description and comparison of performances was designed and implemented in a new computer code. The aim of the paper is to introduce the new software 'EPR-dosimetry performance'. The computer code is a user-friendly tool for providing a full description of method-specific capabilities of EPR tooth dosimetry, from metrological characteristics to practical limitations in applications. The software designed for scientists and engineers has several applications, including support of method calibration by evaluation of calibration parameters, evaluation of critical value and detection limit for registration of radiation-induced signal amplitude, estimation of critical value and detection limit for dose evaluation, estimation of minimal detectable value for anthropogenic dose assessment and description of method uncertainty.

  5. Seeing Red

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This New Horizons image of Jupiter's volcanic moon Io was taken at 13:05 Universal Time during the spacecraft's Jupiter flyby on February 28, 2007. It shows the reddish color of the deposits from the giant volcanic eruption at the volcano Tvashtar, near the top of the sunlit crescent, as well as the bluish plume itself and the orange glow of the hot lava at its source. The relatively unprocessed image on the left provides the best view of the volcanic glow and the plume deposits, while the version on the right has been brightened to show the much fainter plume, and the Jupiter-lit night side of Io.

    New Horizons' color imaging of Io's sunlit side was generally overexposed because the spacecraft's color camera, the super-sensitive Multispectral Visible Imaging Camera (MVIC), was designed for the much dimmer illumination at Pluto. However, two of MVIC's four color filters, the blue and 'methane' filter (a special filter designed to map methane frost on the surface of Pluto at an infrared wavelength of 0.89 microns), are less sensitive than the others, and thus obtained some well-exposed views of the surface when illumination conditions were favorable. Because only two color filters are used, rather than the usual three, and because one filter uses infrared light, the color is only a rough approximation to what the human eye would see.

    The red color of the Tvashtar plume fallout is typical of Io's largest volcanic plumes, including the previous eruption of Tvashtar seen by the Galileo and Cassini spacecraft in 2000, and the long-lived Pele plume on the opposite side of Io. The color likely results from the creation of reddish three-atom and four-atom sulfur molecules (S3 and S4) from plume gases rich in two-atom sulfur molecules (S2 After a few months or years, the S3 and S4 molecules recombine into the more stable and familiar yellowish form of sulfur consisting of eight-atom molecules (S8), so these red deposits are only seen around recently-active Io

  6. Quantitative 3D Optical Imaging: Applications in Dosimetry and Biophysics

    NASA Astrophysics Data System (ADS)

    Thomas, Andrew Stephen

    Optical-CT has been shown to be a potentially useful imaging tool for the two very different spheres of biologists and radiation therapy physicists, but it has yet to live up to that potential. In radiation therapy, researchers have used optical-CT for the readout of 3D dosimeters, but it is yet to be a clinically relevant tool as the technology is too slow to be considered practical. Biologists have used the technique for structural imaging, but have struggled with emission tomography as the reality of photon attenuation for both excitation and emission have made the images quantitatively irrelevant. Dosimetry. The DLOS (Duke Large field of view Optical-CT Scanner) was designed and constructed to make 3D dosimetry utilizing optical-CT a fast and practical tool while maintaining the accuracy of readout of the previous, slower readout technologies. Upon construction/optimization/implementation of several components including a diffuser, band pass filter, registration mount & fluid filtration system the dosimetry system provides high quality data comparable to or exceeding that of commercial products. In addition, a stray light correction algorithm was tested and implemented. The DLOS in combination with the 3D dosimeter it was designed for, PREAGETM, then underwent rigorous commissioning and benchmarking tests validating its performance against gold standard data including a set of 6 irradiations. DLOS commissioning tests resulted in sub-mm isotropic spatial resolution (MTF >0.5 for frequencies of 1.5lp/mm) and a dynamic range of ˜60dB. Flood field uniformity was 10% and stable after 45minutes. Stray light proved to be small, due to telecentricity, but even the residual can be removed through deconvolution. Benchmarking tests showed the mean 3D passing gamma rate (3%, 3mm, 5% dose threshold) over the 6 benchmark data sets was 97.3% +/- 0.6% (range 96%-98%) scans totaling ˜10 minutes, indicating excellent ability to perform 3D dosimetry while improving the speed of

  7. Extremity dosimetry at US Department of Energy facilities

    SciTech Connect

    Harty, R.; Reece, W.D.; MacLellan, J.A.

    1986-05-01

    A questionnaire on extremity dosimetry was distributed to DOE facilities along with a questionnaire on beta dosimetry. An informal telephone survey was conducted as a follow-up survey to answer a few additional questions concerning extremity monitoring practices. The responses to the questionnaire and the telephone survey are summarized in this report. Background information, developed from operational experience and a review of the current literature, is presented as a basis for understanding the information obtained by the survey and questionnaire.

  8. Hanford Internal Dosimetry Program Manual, PNL-MA-552

    SciTech Connect

    Carbaugh, Eugene H.; Bihl, Donald E.; Maclellan, Jay A.

    2003-10-10

    This manual is a guide to the services provided by the Hanford Internal Dosimetry Program (IDP). It describes the roles of and relationships between the IDP and site contractors, and provides recommendations and guidance for consideration in implementing bioassay monitoring and internal dosimetry elements of radiation protection programs. Guidance includes identifying conditions under which workers should be placed on bioassay programs, types, descritptions, and capabilities of measurements, suggested routine bioassay programs, limitations on services, and practices for recording and reporting results.

  9. Surveillance dosimetry of operating power plants

    SciTech Connect

    McElroy, W.N.; Davis, A.I.; Gold, R.

    1981-10-16

    The main focus of the research efforts presently underway is the LWR power reactor surveillance program in which metallurgical test specimens of the reactor PV and dosimetry sensors are placed in three or more surveillance capsules at or near the reactor PV inner wall. They are then irradiated in a temperature and neutron flux-spectrum environment as similar as possible to the PV itself for periods of about 1.5 to 15 effective full-power years (EFPY), with removal of the last capsule at a fluence corresponding to the 30- to 40-year plant end-of-life (EOL) fluence. Because the neutron flux level at the surveillance position is greater than at the vessel, the test is accelerated wit respect to the vessel exposure, allowing early assessment of EOL conditions.

  10. Dosimetry for radiocolloid therapy of cystic craniopharyngiomas.

    PubMed

    Rojas, E Leticia; Al-Dweri, Feras M O; Lallena, Antonio M; Bodineau, Coral; Galán, Pedro

    2003-09-01

    The dosimetry for radiocolloid therapy of cystic craniopharyngiomas is investigated. Analytical calculations based on the Loevinger and the Berger formulas for electrons and photons, respectively, are compared with Monte Carlo simulations. The role of the material of which the colloid introduced inside the craniopharyngioma is made of as well as that forming the cyst wall is analyzed. It is found that the analytical approaches provide a very good description of the simulated data in the conditions where they can be applied (i.e., in the case of a uniform and infinite homogeneous medium). However, the consideration of the different materials and interfaces produces a strong reduction of the dose delivered to the cyst wall in relation to that predicted by the Loevinger and the Berger formulas.

  11. Accidental neutron dosimetry with human hair

    NASA Astrophysics Data System (ADS)

    Ekendahl, Daniela; Bečková, Věra; Zdychová, Vlasta; Bulánek, Boris; Prouza, Zdeněk; Štefánik, Milan

    2014-11-01

    Human hair contains sulfur, which can be activated by fast neutrons. The 32S(n,p)32P reaction with a threshold of 2.5 MeV was used for fast neutron dose estimation. It is a very important parameter for individual dose reconstruction with regards to the heterogeneity of the neutron transfer to the human body. Samples of human hair were irradiated in a radial channel of a training reactor VR-1. 32P activity in hair was measured both, directly by means of a proportional counter, and as ash dispersed in a liquid scintillator. Based on neutron spectrum estimation, a relationship between the neutron dose and induced activity was derived. The experiment verified the practical feasibility of this dosimetry method in cases of criticality accidents or malevolent acts with nuclear materials.

  12. Pediatric renal iodine-123 orthoiodohippurate dosimetry

    SciTech Connect

    Marcus, C.S.; Kuperus, J.H.

    1985-10-01

    Radiation exposure to the kidney from iodine- ST orthoiodohippurate (( STI)OIH) and any associated ( SUI)OIH contamination may vary by a factor of several hundred depending upon the health of the kidney. Calculations of kidney dose were made for patients with the following renal states: normal, acute tubular necrosis (ATN), obstruction, and renal transplant. The dosimetry was based on a minimum practical administered activity (MPAA) of 200 microCi for pediatric patients and 500 microCi for adults. High-grade obstruction of recent onset and severe ATN are the only disease processes which could result in high exposures, and this is due primarily to the contribution of SUI. For selected cases, OIH labeled with pure STI should be very seriously considered.

  13. Neutron generator (HIRRAC) and dosimetry study.

    PubMed

    Endo, S; Hoshi, M; Takada, J; Tauchi, H; Matsuura, S; Takeoka, S; Kitagawa, K; Suga, S; Komatsu, K

    1999-12-01

    Dosimetry studies have been made for neutrons from a neutron generator at Hiroshima University (HIRRAC) which is designed for radiobiological research. Neutrons in an energy range from 0.07 to 2.7 MeV are available for biological irradiations. The produced neutron energies were measured and evaluated by a 3He-gas proportional counter. Energy spread was made certain to be small enough for radiobiological studies. Dose evaluations were performed by two different methods, namely use of tissue equivalent paired ionization chambers and activation of method with indium foils. Moreover, energy deposition spectra in small targets of tissue equivalent materials, so-called lineal energy spectrum, were also measured and are discussed. Specifications for biological irradiation are presented in terms of monoenergetic beam conditions, dose rates and deposited energy spectra.

  14. Liulin-type spectrometry-dosimetry instruments.

    PubMed

    Dachev, Ts; Dimitrov, Pl; Tomov, B; Matviichuk, Yu; Spurny, F; Ploc, O; Brabcova, K; Jadrnickova, I

    2011-03-01

    The main purpose of Liulin-type spectrometry-dosimetry instruments (LSDIs) is cosmic radiation monitoring at the workplaces. An LSDI functionally is a low mass, low power consumption or battery-operated dosemeter. LSDIs were calibrated in a wide range of radiation fields, including radiation sources, proton and heavy-ion accelerators and CERN-EC high-energy reference field. Since 2000, LSDIs have been used in the scientific programmes of four manned space flights on the American Laboratory and ESA Columbus modules and on the Russian segment of the International Space Station, one Moon spacecraft and three spacecraft around the Earth, one rocket, two balloons and many aircraft flights. In addition to relative low price, LSDIs have proved their ability to qualify the radiation field on the ground and on the above-mentioned carriers.

  15. Space radiation dosimetry using bubble detectors.

    PubMed

    Ing, H; Mortimer, A

    1994-10-01

    Bubble detectors--a new development in radiation detection--has only recently been used for radiation measurements in space. One important characteristic of the bubble detector is that it operates on a phenomenon which bears considerable resemblance to biological response. Recent experimental results from irradiating bubble detectors with high-energy heavy ions point to the need to re-examine the methodology used for assessing space radiation and the relevance of conventional quantities such as dose equivalent for space dosimetry. It may be that biological hazard associated with the intensely ionizing events--associated with nuclear fragmentation but delivering relatively small dose equivalent--may be much more important than that associated with lightly ionizing events which comprise the bulk of the conventional radiation dose equivalent.

  16. Dosimetry in mixed neutron-gamma fields

    SciTech Connect

    Remec, I.

    1998-04-01

    The gamma field accompanying neutrons may, in certain circumstances, play an important role in the analysis of neutron dosimetry and even in the interpretation of radiation induced steel embrittlement. At the High Flux Isotope Reactor pressure vessel the gamma induced reactions dominate the responses of {sup 237}Np and {sup 238}U dosimeters, and {sup 9}Be helium accumulation fluence monitors. The gamma induced atom displacement rate in steel is higher than corresponding neutron rate, and is the cause of ``accelerated embrittlement`` of HFIR materials. In a large body of water, adjacent to a fission plate, photofissions contribute significantly to the responses of fission monitors and need to be taken into account if the measurements are used for the qualification of the transport codes and cross-section libraries.

  17. Gastroesophageal scintiscanning in a pediatric population: dosimetry

    SciTech Connect

    Castronovo, F.P. Jr.

    1986-07-01

    The dosimetry associated with orally administered (/sup 99m/Tc)sulfur colloid for the diagnosis of gastroesophageal reflux has not been adequately described for the pediatric populations. Standard MIRD methodology was performed for the following: newborn, 1, 5, 10, and 15 yr old, and adult standard man. The critical organ for all pediatric groups was the lower large intestine with absorbed dose of 0.927, 0.380, 0.194, 0.120 and 0.0721 rad/100 microCi, respectively. For the adult the critical organ was the upper large intestine with an absorbed dose of 0.0518 rad/100 microCi. These data should be considered when administering (99mTc)sulfur colloid orally in a pediatric population.

  18. Flow Dynamics and HSPC Homing in Bone Marrow Microvessels.

    PubMed

    Bixel, M Gabriele; Kusumbe, Anjali P; Ramasamy, Saravana K; Sivaraj, Kishor K; Butz, Stefan; Vestweber, Dietmar; Adams, Ralf H

    2017-02-14

    Measurements of flow velocities at the level of individual arterial vessels and sinusoidal capillaries are crucial for understanding the dynamics of hematopoietic stem and progenitor cell homing in the bone marrow vasculature. We have developed two complementary intravital two-photon imaging approaches to determine blood flow dynamics and velocities in multiple vessel segments by capturing the motion of red blood cells. High-resolution spatiotemporal measurements through a cranial window to determine short-time dynamics of flowing blood cells and repetitive centerline scans were used to obtain a detailed flow-profile map with hemodynamic parameters. In addition, we observed the homing of individual hematopoietic stem and progenitor cells and obtained detailed information on their homing behavior. With our imaging setup, we determined flow patterns at cellular resolution, blood flow velocities and wall shear stress in small arterial vessels and highly branched sinusoidal capillaries, and the cellular dynamics of hematopoietic stem and progenitor cell homing.

  19. Review of the near-earth space radiation dosimetry

    NASA Astrophysics Data System (ADS)

    Guo, Jianming; Chen, Xiaoqian; Li, Shiyou

    2016-07-01

    The near-earth space radiation environment has a great effect to the spacecraft and maybe do harm to the astronaut's health. Thus, how to measure the radiation has become a serious challenge. In order to provide sufficient protection both for astronauts and for instruments on-board, dose equivalent and linear energy transfer should be measured instead of merely measuring total radiation dose. This paper reviews the methods of radiation measurement and presents a brief introduction of dosimetry instruments. The method can be divided into two different kinds, i.e., positive dosimetry and passive dosimetry. The former usually includes electronic devices which can be used for data storage and can offer simultaneous monitoring on space radiation. The passive dosimetry has a much simple structure, and need extra operation after on-orbit missions for measuring. To get more reliable data of radiation dosimetry, various instruments and methods had been applied in the spacecrafts and the manned spacecrafts in particular. The outlook of the development in the space radiation dosimetry measurement is also presented.

  20. Boron dose determination for BNCT using Fricke and EPR dosimetry

    SciTech Connect

    Wielopolski, L.; Ciesielski, B.

    1995-02-01

    In Boron Neutron Capture Therapy (BNCT) the dominant dose delivered to the tumor is due to {alpha} and {sup 7}Li charged particles resulting from a neutron capture by {sup 10}B and is referred to herein as the boron dose. Boron dose is directly attributable to the following two independent factors, one boron concentration and the neutron capture energy dependent cross section of boron, and two the energy spectrum of the neutrons that interact with boron. The neutron energy distribution at a given point is dictated by the incident neutron energy distribution, the depth in tissue, geometrical factors such as beam size and patient`s dimensions. To account for these factors can be accommodated by using Monte Carlo theoretical simulations. However, in conventional experimental BNCT dosimetry, e.g., using TLDs or ionization chambers, it is only possible to estimate the boron dose. To overcome some of the limitations in the conventional dosimetry, modifications in ferrous sulfate dosimetry (Fricke) and Electron Paramagnetic Resonance (EPR) dosimetry in alanine, enable to measure specifically boron dose in a mixed gamma neutron radiation fields. The boron dose, in either of the dosimeters, is obtained as a difference between measurements with boronated and unboronated dosimeters. Since boron participates directly in the measurements, the boron dosimetry reflects the true contribution, integral of the neutron energy spectrum with boron cross section, of the boron dose to the total dose. Both methods are well established and used extensively in dosimetry, they are presented briefly here.

  1. Specific issues in small animal dosimetry and irradiator calibration

    PubMed Central

    Yoshizumi, Terry; Brady, Samuel L.; Robbins, Mike E.; Bourland, J. Daniel

    2013-01-01

    Purpose In response to the increased risk of radiological terrorist attack, a network of Centers for Medical Countermeasures against Radiation (CMCR) has been established in the United States, focusing on evaluating animal model responses to uniform, relatively homogenous whole- or partial-body radiation exposures at relatively high dose rates. The success of such studies is dependent not only on robust animal models but on accurate and reproducible dosimetry within and across CMCR. To address this issue, the Education and Training Core of the Duke University School of Medicine CMCR organised a one-day workshop on small animal dosimetry. Topics included accuracy in animal dosimetry accuracy, characteristics and differences of cesium-137 and X-ray irradiators, methods for dose measurement, and design of experimental irradiation geometries for uniform dose distributions. This paper summarises the information presented and discussed. Conclusions Without ensuring accurate and reproducible dosimetry the development and assessment of the efficacy of putative countermeasures will not prove successful. Radiation physics support is needed, but is often the weakest link in the small animal dosimetry chain. We recommend: (i) A user training program for new irradiator users, (ii) subsequent training updates, and (iii) the establishment of a national small animal dosimetry center for all CMCR members. PMID:21961967

  2. Neutron dosimetry in boron neutron capture therapy

    SciTech Connect

    Fairchild, R.G.; Miola, U.J.; Ettinger, K.V.

    1981-01-01

    The recent development of various borated compounds and the utilization of one of these (Na/sub 2/B/sub 12/H/sub 11/SH) to treat brain tumors in clinical studies in Japan has renewed interest in neutron capture therapy. In these procedures thermal neutrons interact with /sup 10/B in boron containing cells through the /sup 10/B(n,..cap alpha..)/sup 7/Li reaction producing charged particles with a maximum range of approx. 10..mu..m in tissue. Borated analogs of chlorpromazine, porphyrin, thiouracil and deoxyuridine promise improved tumor uptake and blood clearance. The therapy beam from the Medical Research Reactor in Brookhaven contains neutrons from a modified and filtered fission spectrum and dosimetric consequences of the use of the above mentioned compounds in conjunction with thermal and epithermal fluxes are discussed in the paper. One of the important problems of radiation dosimetry in capture therapy is determination of the flux profile and, hence, the dose profile in the brain. This has been achieved by constructing a brain phantom made of TE plastic. The lyoluminescence technique provides a convenient way of monitoring the neutron flux distributions; the detectors for this purpose utilize /sup 6/Li and /sup 10/B compounds. Such compounds have been synthesized specially for the purpose of dosimetry of thermal and epithermal beams. In addition, standard lyoluminescent phosphors, like glutamine, could be used to determine the collisional component of the dose as well as the contribution of the /sup 14/N(n,p)/sup 14/C reaction. Measurements of thermal flux were compared with calculations and with measurements done with activation foils.

  3. Real-time volumetric scintillation dosimetry

    NASA Astrophysics Data System (ADS)

    Beddar, S.

    2015-01-01

    The goal of this brief review is to review the current status of real-time 3D scintillation dosimetry and what has been done so far in this area. The basic concept is to use a large volume of a scintillator material (liquid or solid) to measure or image the dose distributions from external radiation therapy (RT) beams in three dimensions. In this configuration, the scintillator material fulfills the dual role of being the detector and the phantom material in which the measurements are being performed. In this case, dose perturbations caused by the introduction of a detector within a phantom will not be at issue. All the detector configurations that have been conceived to date used a Charge-Coupled Device (CCD) camera to measure the light produced within the scintillator. In order to accurately measure the scintillation light, one must correct for various optical artefacts that arise as the light propagates from the scintillating centers through the optical chain to the CCD chip. Quenching, defined in its simplest form as a nonlinear response to high-linear energy transfer (LET) charged particles, is one of the disadvantages when such systems are used to measure the absorbed dose from high-LET particles such protons. However, correction methods that restore the linear dose response through the whole proton range have been proven to be effective for both liquid and plastic scintillators. Volumetric scintillation dosimetry has the potential to provide fast, high-resolution and accurate 3D imaging of RT dose distributions. Further research is warranted to optimize the necessary image reconstruction methods and optical corrections needed to achieve its full potential.

  4. On flattening filter-free portal dosimetry.

    PubMed

    Pardo, Eduardo; Castro Novais, Juan; Molina López, María Yolanda; Ruiz Maqueda, Sheila

    2016-07-08

    Varian introduced (in 2010) the option of removing the flattening filter (FF) in their C-Arm linacs for intensity-modulated treatments. This mode, called flattening filter-free (FFF), offers the advantage of a greater dose rate. Varian's "Portal Dosimetry" is an electronic portal imager device (EPID)-based tool for IMRT verification. This tool lacks the capability of verifying flattening filter-free (FFF) modes due to saturation and lack of an image prediction algorithm. (Note: the latest versions of this software and EPID correct these issues.) The objective of the present study is to research the feasibility of said verifications (with the older versions of the software and EPID). By placing the EPID at a greater distance, the images can be acquired without saturation, yielding a linearity similar to the flattened mode. For the image prediction, a method was optimized based on the clinically used algorithm (analytical anisotropic algorithm (AAA)) over a homogeneous phantom. The depth inside the phantom and its electronic density were tailored. An application was developed to allow the conversion of a dose plane (in DICOM format) to Varian's custom format for Portal Dosimetry. The proposed method was used for the verification of test and clinical fields for the three qualities used in our institution for IMRT: 6X, 6FFF and 10FFF. The method developed yielded a positive verification (more than 95% of the points pass a 2%/2 mm gamma) for both the clinical and test fields. This method was also capable of "predicting" static and wedged fields. A workflow for the verification of FFF fields was developed. This method relies on the clinical algorithm used for dose calculation and is able to verify the FFF modes, as well as being useful for machine quality assurance. The procedure described does not require new hardware. This method could be used as a verification of Varian's Portal Dose Image Prediction.

  5. Bone marrow examination in pancytopenia.

    PubMed

    Rangaswamy, M; Prabhu; Nandini, N M; Manjunath, G V

    2012-08-01

    Pancytopenia is defined by reduction of all the three formed elements of blood below the normal reference. It may be a manifestation of a wide variety of disorders, which primarily or secondarily affect the bone marrow. Haematological investigation forms the bedrock in the management of patients with pancytopenia and therefore needs detailed study. The total number of cases studied were 100 over a period of two years in the department of pathology, JSS Hospital, Mysore. Megaloblastic anaemia (33%) was the commonest cause of pancytopenia. Other causes were nutritional anaemia (16%), aplastic anaemia (14%), hypersplenism (10%), sepsis (9%) and leukaemia (5%). Less common causes were alcoholic liver disease, haemolytic anaemia, HIV, dengue, systemic lupus erythematosus, viral hepatitis, disseminated TB and multiple myeloma. Most of the patients were in the age group of 11-30 years with a male:female ratio of 1.6:1.Generalised weakness and fatigue (88%) were the commonest presenting complaints. Haemoglobin level varied from 1-10 g/dl with majorIty (70%) of them in the range of 5.1-10 g/dI. TLC was in the range of 500-4000 cells/cmm. Most (34%) of them had 3100-4000 cells/cmm. Platelet count was in the range of 4000-1,40,000 cells/cmm. Reticulocyte count varied from 0.1%-15% with majority (82%) of them ranging from 0.1%-2%. The bone marrow cellularity was hypocellular in 14%, hypercellular in 75%, and normocellular in 11% of the patients. Pancytopenia is a relatively common entity with inadequate attention in Indian subcontinent. A comprehensive clinical and haematological study of patients with pancytopenia will usually help in the identification of the underlying cause. However in view of wide array of aetiologies, pancytopenia continues to be a diagnostic challenge for haematologists.

  6. Pharmacokinetics and normal organ dosimetry following intraperitoneal rhenium-186-labeled monoclonal antibody

    SciTech Connect

    Breitz, H.B.; Durham, J.S.; Fisher, D.R. |||

    1995-05-01

    Pharmacokinetics, biodistribution and radiation dose estimates following intraperitoneal administration of a {sup 186}Re-labeled murine antibody, NR-LU-10, were assessed in 27 patients with advanced ovarian cancer. Quantitative gamma camera imaging and gamma counting of serum and intraperitoneal fluid radioactivity were used to obtain data for dosimetry estimation. The MIRD intraperitoneal model was used to estimate dose to normal organs from radioactivity within the peritoneal cavity. The absorbed dose to normal peritoneum was estimated in two ways: from the gamma camera activity and peritoneal fluid samples. Serum activity peaked at 44 hr and depended on the concentration of radioactivity in the peritoneal fluid. Mean cumulative urinary excretion of {sup 186}Re was 50% by 140 hr. Estimates of radiation absorbed dose to normal organs in rad/mCi administered (mean {plus_minus} s.d.) were whole body 0.7 {plus_minus} 0.3; marrow 0.4 {plus_minus}0.1; liver 1.9 {plus_minus}0.9; lungs 1.3 {plus_minus} 0.7; kidneys 0.2 {plus_minus} 0.2; intestine 0.2 {plus_minus}0.2. Peritoneal surface dose estimates varied depending on the volume of fluid infused and the method of dose determination. Using gamma camera data, the peritoneal dose ranged for 7 to 36 rad/mCi. Using peritoneal fluid sample data, the dose ranged from 2 to 25 rad/mCi. Significant myelosuppression was observed at marrow doses above 100 rad. Noninvasive methods of dose estimation for intraperitoneal administration of radioimmunoconjugates provide reasonable estimates when compared with previously described methods. 31 refs., 6 figs., 2 tabs.

  7. Murine bone marrow IgA responses to orally administered sheep erythrocytes.

    PubMed

    Alley, C D; Kiyono, H; McGhee, J R

    1986-06-15

    Specific immunization protocols have been established for the induction of murine bone marrow IgA responses to the T cell-dependent (TD) antigen sheep red blood cells (SRBC). Systemic immunization, either i.p. or i.v., followed by a second injection, induced splenic IgM and IgG responses and a bone marrow IgM response. No significant IgA responses were observed in either lymphoid tissue compartment. Oral immunization with SRBC by gastric intubation for 2 days, followed 1 wk later by an i.p. injection of SRBC resulted in a splenic IgA plaque-forming cell (PFC) response, but did not elicit a bone marrow IgA response. Repeated daily gastric intubation of SRBC to C3H/HeN and C3H/HeJ mice led to the previously reported pattern of systemic unresponsiveness in C3H/HeN mice and good anamnestic type IgM, IgG, and IgA splenic anti-SRBC PFC responses in the C3H/HeJ strain upon parenteral challenge. Oral administration of SRBC for 14 days to C3H/HeN mice, followed by systemic SRBC challenge, resulted in diminished splenic PFC responses of all isotypes, whereas gastric intubation of SRBC for 28 days led to complete systemic unresponsiveness to antigen in C3H/HeN mice. Interestingly, the repeated oral administration of SRBC resulted in significant bone marrow IgA PFC responses upon i.p. challenge in both C3H/HeN and C3H/HeJ mouse strains. The bone marrow IgA responses were clearly dependent upon chronic oral exposure to SRBC, because gastric intubation with SRBC for 2 consecutive days/wk for 10 wk also induced bone marrow and splenic IgA anti-SRBC PFC responses in C3H/HeN mice. These results suggest that memory B cells reside in the bone marrow of orally immunized mice and can yield anamnestic-type responses to challenge with the inducing antigen. The memory cells may arise in the Peyer's patches of the gut and migrate to the bone marrow. The possibility that the bone marrow is a component of the common mucosal immune system in mammals is suggested by this study.

  8. Megakaryocytes, malignancy and bone marrow vascular niches.

    PubMed

    Psaila, B; Lyden, D; Roberts, I

    2012-02-01

    Dynamic interactions between hematopoietic cells and their specialized bone marrow microenvironments, namely the vascular and osteoblastic 'niches', regulate hematopoiesis. The vascular niche is conducive for thrombopoiesis and megakaryocytes may, in turn, regulate the vascular niche, especially in supporting vascular and hematopoietic regeneration following irradiation or chemotherapy. A role for platelets in tumor growth and metastasis is well established and, more recently, the vascular niche has also been implicated as an area for preferential homing and engraftment of malignant cells. This article aims to provide an overview of the dynamic interactions between cellular and molecular components of the bone marrow vascular niche and the potential role of megakaryocytes in bone marrow malignancy.

  9. [Increased efficacy of allogenic bone marrow transplantation].

    PubMed

    Fedotenkov, A G; Danilova, L A; Ignasheva, L P

    1982-08-01

    Experiments made in vivo and vitro have demonstrated that conservation of allogeneic hemopoietic tissue with glycerin brings about a decrease in transplatation, homologous activity of T lymphocytes. Allogeneic bone marrow conserved with glycerin compares very favourably with freshly prepared allogeneic bone marrow since the transplant-versus-host reaction is attenuated under the effect of glycerin. Moreover, it shows a higher proliferative activity. The glycerin-induced reduction of the inactivating effect of lymphocytes against non-syngeneic colony-forming units enables the conserved bone marrow to be transplanted from several donors.

  10. Pituitary abscess after autologous bone marrow transplantation.

    PubMed

    Leff, R S; Martino, R L; Pollock, W J; Knight, W A

    1989-05-01

    The first case of pituitary abscess arising in a patient during recovery from autologous bone marrow transplantation is reported. A 31-year-old man with a 9 month history of T-cell lymphoma died suddenly more than 60 days after successful treatment with high-dose cyclophosphamide, total body irradiation, and autologous bone marrow infusion. Autopsy revealed a pituitary abscess associated with clinically silent sphenoid sinusitis. Unique aspects of this case are presented and clinical and pathologic features of pituitary abscess are reviewed. Although rare, pituitary abscess may complicate recovery from bone marrow transplantation.

  11. A comparison of 111In with 52Fe and 99mTc-sulfur colloid for bone marrow scanning.

    PubMed

    Merrick, M V; Gordon-Smith, E C; Lavender, J P; Szur, L

    1975-01-01

    Under most circumstances 52Fe, 111In, and colloid show a similar distribution of marrow. The lesser uptake of 111In by liver and spleen may occasionally be of value in permitting visualization of that portion of the spinal marrow obscured by these organs in the colloid scan. However, in red cell aplasia, when there is dissociation between phagocytic and erythropoietic functions, scanning with 111In gives no information about erythropoietic tissue distribution. Therefore, indium cannot be used as an analog for iron in the study of the hematopoietic system.

  12. Analyzing the cellular contribution of bone marrow to fracture healing using bone marrow transplantation in mice

    SciTech Connect

    Colnot, C. . E-mail: colnotc@orthosurg.ucsf.edu; Huang, S.; Helms, J.

    2006-11-24

    The bone marrow is believed to play important roles during fracture healing such as providing progenitor cells for inflammation, matrix remodeling, and cartilage and bone formation. Given the complex nature of bone repair, it remains difficult to distinguish the contributions of various cell types. Here we describe a mouse model based on bone marrow transplantation and genetic labeling to track cells originating from bone marrow during fracture healing. Following lethal irradiation and engraftment of bone marrow expressing the LacZ transgene constitutively, wild type mice underwent tibial fracture. Donor bone marrow-derived cells, which originated from the hematopoietic compartment, did not participate in the chondrogenic and osteogenic lineages during fracture healing. Instead, the donor bone marrow contributed to inflammatory and bone resorbing cells. This model can be exploited in the future to investigate the role of inflammation and matrix remodeling during bone repair, independent from osteogenesis and chondrogenesis.

  13. Role of bone marrow macrophages in controlling homeostasis and repair in bone and bone marrow niches.

    PubMed

    Kaur, Simranpreet; Raggatt, Liza Jane; Batoon, Lena; Hume, David Arthur; Levesque, Jean-Pierre; Pettit, Allison Robyn

    2017-01-01

    Macrophages, named for their phagocytic ability, participate in homeostasis, tissue regeneration and inflammatory responses. Bone and adjacent marrow contain multiple functionally unique resident tissue macrophage subsets which maintain and regulate anatomically distinct niche environments within these interconnected tissues. Three subsets of bone-bone marrow resident tissue macrophages have been characterised; erythroblastic island macrophages, haematopoietic stem cell niche macrophages and osteal macrophages. The role of these macrophages in controlling homeostasis and repair in bone and bone marrow niches is reviewed in detail.

  14. EDITORIAL: Special issue on radiation dosimetry Special issue on radiation dosimetry

    NASA Astrophysics Data System (ADS)

    Sharpe, Peter

    2009-04-01

    This special issue of Metrologia on radiation dosimetry is the second in a trilogy on the subject of ionizing radiation measurements, a field that is overseen by Sections I, II and III of the CIPM's Consultative Committee for Ionizing Radiation (CCRI). The work of Section II, on radionuclide metrology, was covered in issue 44(4), published in 2007, and that of Section III, on neutron metrology, will be covered in a special issue to be published shortly. This issue covers the work of Section I (x-rays and γ rays, and charged particles). The proposal to publish special issues of Metrologia covering the work of the CCRI Sections was first made in 2003 and refined at the two subsequent meetings of the CCRI in 2005 and 2007. The overall aim is to present the work of the CCRI to a wider metrological audience and to highlight the relevance and importance of the field. The main focus of our special issue on dosimetry metrology is on the 'state of the art' in the various areas covered, with an indication of the current developments taking place and the problems and challenges that remain. Where appropriate, this is set in a brief historical context, although it is not the aim to give a historical review. The need for accurate measurement has been appreciated from the pioneering days of the use of ionizing radiation in the early 20th century, particularly in the fields of diagnostic and therapeutic medicine. Over the years, the range of applications for ionizing radiation has expanded both in scope and in the types and energies of radiation employed. This has led to the need to develop a wide variety of measurement techniques and standards covering fields ranging from the low doses experienced in environmental and protection applications to the extremely high doses used in industrial processing. The different types of radiation employed give rise to the need for dose measurements in radiation beams whose effective penetration through a material such as water ranges from a

  15. Bone marrow-derived lung epithelial cells.

    PubMed

    Krause, Diane S

    2008-08-15

    Bone marrow-derived cells can take on the phenotype of epithelial cells and express epithelial-specific genes in multiple organs. Here, we focus on recent data on the appearance of marrow-derived epithelial cells in the adult lung. These findings have garnered significant skepticism because in most cases marrow-derived epithelial cells are very rare, the marrow cell of origin is not known, the techniques for detection have needed improvement, and there seem to be multiple mechanisms by which this occurs. Recent studies have focused on these concerns. Once these important concerns are addressed, further studies on the function(s) of these cells will need to be performed to determine whether this engraftment has any clinical significance-either beneficial or detrimental.

  16. Psycholegal issues in sibling bone marrow donation.

    PubMed

    Weisz, Victoria

    1992-01-01

    The only hope of survival for children with a number of life-threatening illnesses is a successful bone marrow transplant (BMT). Unlike the treatment source for most therapies, the raw material for transplant therapy comes from a human being. Although many BMTs are autologous, utilizing the patient's own bone marrow, a large percentage of childhood BMTs rely on bone marrow from children or adolescents who are biological siblings to the sick child. Medical and legal systems are confronted with a dilemma when healthy children are needed to undergo minimally risky, yet somewhat painful, procedures for the benefit of their critically ill siblings. This article reviews legal issues involved in sibling bone marrow donation and psychological research that is relevant to those issues. The article concludes with proposed directions for future psycholegal research and a discussion of ethical issues that are not amenable to empirical investigation.

  17. Bone marrow transplant – children - discharge

    MedlinePlus

    Transplant - bone marrow - children - discharge; Stem cell transplant - children - discharge; Hematopoietic stem cell transplant -children - discharge; Reduced intensity, non-myeloablative transplant - children - discharge; Mini transplant - children - discharge; Allogenic ...

  18. Induction of marrow hypoxia by radioprotective agents

    SciTech Connect

    Allalunis-Turner, M.J.; Walden, T.L.; Sawich, C.

    1989-01-01

    Many compounds that possess sulfhydryl groups have been shown to protect bone marrow from radiation injury. The most effective thiol radioprotective agent is ethiofos (S-2-(3-aminopropylamino)ethylphosphorothoic acid or WR-2721). The ability of thiol and non-thiol radioprotectors to induce hypoxia was determined using binding of ({sup 3}H)misonidazole by bone marrow cells as a measure of hypoxia. When administered at maximally radioprotective doses, four drugs (WR-2721, cysteamine, 5-hydroxytryptamine, and 16,16-dimethyl prostaglandin E2) significantly increased the amount of ({sup 3}H)misonidazole bound by marrow cells, while no significant increase in binding was observed with three other agents (endotoxin, AET, superoxide dimutase). Doses of WR-2721 previously shown to provide suboptimal radioprotection did not significantly increase {sup 3}H-misonidazole binding. These results suggest that the physiological effects of some radioprotectors, that is, their ability to induce marrow hypoxia, may contribute to their efficacy in vivo.

  19. The bone marrow aspirate and biopsy in the diagnosis of unsuspected nonhematologic malignancy: A clinical study of 19 cases

    PubMed Central

    Ozkalemkas, Fahir; Ali, Rıdvan; Ozkocaman, Vildan; Ozcelik, Tulay; Ozan, Ulku; Ozturk, Hulya; Kurt, Ender; Evrensel, Turkkan; Yerci, Omer; Tunali, Ahmet

    2005-01-01

    Background Although bone marrow metastases can be found commonly in some malignant tumors, diagnosing a nonhematologic malignancy from marrow is not a usual event. Methods To underscore the value of bone marrow aspiration and biopsy as a short cut in establishing a diagnosis for disseminated tumors, we reviewed 19 patients with nonhematologic malignancies who initially had diagnosis from bone marrow. Results The main indications for bone marrow examination were microangiopathic hemolytic anemia (MAHA), leukoerythroblastosis (LEB) and unexplained cytopenias. Bone marrow aspiration was not diagnostic due to dry tap or inadequate material in 6 cases. Biopsy results were parallel to the cytological ones in all cases except one; however a meticulous second examination of the biopsy confirmed the cytologic diagnosis in this patient too. The most common histologic subtype was adenocarcinoma, and after all the clinical and laboratory evaluations, the primary focus was disclosed definitively in ten patients (5 stomach, 3 prostate, 1 lung, 1 muscle) and probably in four patients (3 gastrointestinal tract, 1 lung). All work up failed in five patients and these cases were classified as tumor of unknown origin (TUO). Conclusion Our series showed that anemia, thrombocytopenia, elevated red cell distribution width (RDW) and hypoproteinemia formed a uniform tetrad in patients with disseminated tumors that were diagnosed via bone marrow examination. The prognosis of patients was very poor and survivals were only a few days or weeks (except for 4 patients whose survivals were longer). We concluded that MAHA, LEB and unexplained cytopenias are strong indicators of the necessity of bone marrow examination. Because of the very short survival of many patients, all investigational procedures should be judged in view of their rationality, and should be focused on treatable primary tumors. PMID:16262899

  20. Radiation Dose Deposition in the Active Marrow of Reference Man.

    DTIC Science & Technology

    1977-10-31

    gamma ray-fission neutron exposure , the relative biological effec- tiveness (RBE) per unit marrow dose between neutrons and gamma rays in producing...calculations in terms of marrow dose (rad (marrow)) per unit incident fluence. The third presents in- tegral marrow doses calculated for exposure to...in the marrow than other devices. This is shown by the fact that the neutron dose deposited by a given total exposure from such a de- vice is as much

  1. [Technic and dosimetry in total body irradiation with 18 MeV photons].

    PubMed

    Ragona, R; Anglesio, S; Urgesi, A; Monetti, U; Rossi, G; Tessa, M

    1987-05-01

    Total body irradiation (TBI) is used in our Institution in the conditioning regimen for bone marrow transplantation. The fractionation pattern consists of two daily fractions of 1.65 Gy repeated for 4 days (total dose 13.20 Gy in 8 fractions). Lung dose is reduced by means of lead custom shaped shields directly strapped to the patient surface. TBI is delivered by a THERAC 20 linear accelerator with two opposing AP-PA photon beams with a maximum energy of 18 MeV. Treatment distance is 340 cm and the patient is treated in a semi-standing position. Dosimetry studies in a homogeneous phantom were performed in the treatment geometry and consisted in the determination of: tissue maximum ratios (TMR) at different depths, absorbed dose along the median axis and the diagonal of the field, variation of the absorbed dose in the prescription point with different volumes of scattering material, and transmission of shielding and compensating material. A semi-empiric formula for the calculation of absorbed dose in a point has been obtained. A subsequent study in a Rando phantom with termoluminescent dosimeters (TLD) has shown a +/- 5% agreement between calculated and measured values and a +/- 7% homogeneity.

  2. Bone marrow lesions: A systematic diagnostic approach

    PubMed Central

    Grande, Filippo Del; Farahani, Sahar J; Carrino, John A; Chhabra, Avneesh

    2014-01-01

    Bone marrow lesions on magnetic resonance (MR) imaging are common and may be seen with various pathologies. The authors outline a systematic diagnostic approach with proposed categorization of various etiologies of bone marrow lesions. Utilization of typical imaging features on conventional MR imaging techniques and other problem-solving techniques, such as chemical shift imaging and diffusion-weighted imaging (DWI), to achieve accurate final diagnosis has been highlighted. PMID:25114392

  3. Redox Regulation in Bone Marrow Failure

    DTIC Science & Technology

    2012-06-01

    aplastic anemia patients with a p38 MAPK inhibitor can restore defective hematopoietic activity, suggesting the critical role of p38 in bone marrow...hematopoietic stem cells, and eventually leading to bone marrow failure [7, 8] [9] [10]. On the other hand, treating aplastic anemia patients with a p38...in aplastic anemia . J Immunol, 2002. 168(12): p. 5984-8. 12. Ikebuchi, K., et al., Interleukin 6 enhancement of interleukin 3-dependent

  4. Dosimetry and toxicity of Samarium-153-EDTMP administered for bone pain due to skeletal metastases

    SciTech Connect

    Bayouth, J.E.; Macey, D.J.; Kasi, L.P.

    1994-01-01

    Palliation of bone pain in patients with cancer metastatic to bone is being evaluated in several cancer centers by the administration of the bone-seeking phosphonate ethylenediaminetetramethylenephosphonic acid (EDTMP) chelated with the beta particle-emitting radionuclide {sup 153}Sm. In this study {sup 153}Sm-EDTMP was intravenously injected into 19 patients over a 1-min period. Patients received up to four injections of 18.5 MBq (0.5 mCi) or 37 MBq (1.0mCi) per kilogram of body weight. Skeletal retention was calculated from urinary excretion. No uptake of {sup 153}Sm-EDTMP in nonskeletal tissues was observed in whole-body gamma camera images. The mean skeletal uptake for all patients was 54% {plus_minus} 16% of the injected dose (%ID). This resulted in the bone marrow receiving 89 cGy/GBq {plus_minus} 27 cGy/GBq (3.28 cGy/mCi {plus_minus} 0.99 cGy/mCi), with calculated marrow doses ranging from 27 cGy to 338 cGy. For each patient, the estimated radiation absorbed dose to the marrow was correlated to the percent decrease in platelet number, ranging from 7.4% to 78.9%. Since the deviation of uptake between the four injections for a given patient (7.6% ID) was less than the deviation for all patients (16% ID), the initial dose may be used to estimate the skeletal uptake for the remaining doses. These radiation dose estimates permit patients at risk to be identified prior to reaching myelotoxicity and develop dose-response models. Thirteen patients (68%) reported significant pain relief from this radionuclide therapy. Bone pain appears to be alleviated by {sup 153}Sm-EDTMP with limited red marrow doses and no toxic effects in other organs. 15 refs., 8 figs., 2 figs.

  5. Bone marrow osteoblast vulnerability to chemotherapy.

    PubMed

    Gencheva, Marieta; Hare, Ian; Kurian, Susan; Fortney, Jim; Piktel, Debbie; Wysolmerski, Robert; Gibson, Laura F

    2013-06-01

    Osteoblasts are a major component of the bone marrow microenvironment, which provide support for hematopoietic cell development. Functional disruption of any element of the bone marrow niche, including osteoblasts, can potentially impair hematopoiesis. We have studied the effect of two widely used drugs with different mechanisms of action, etoposide (VP16) and melphalan, on murine osteoblasts at distinct stages of maturation. VP16 and melphalan delayed maturation of preosteoblasts and altered CXCL12 protein levels, a key regulator of hematopoietic cell homing to the bone marrow. Sublethal concentrations of VP16 and melphalan also decreased the levels of several transcripts which contribute to the composition of the extracellular matrix (ECM) including osteopontin (OPN), osteocalcin (OCN), and collagen 1A1 (Col1a1). The impact of chemotherapy on message and protein levels for some targets was not always aligned, suggesting differential responses at the transcription and translation or protein stability levels. As one of the main functions of a mature osteoblast is to synthesize ECM of a defined composition, disruption of the ratio of its components may be one mechanism by which chemotherapy affects the ability of osteoblasts to support hematopoietic recovery coincident with altered marrow architecture. Collectively, these observations suggest that the osteoblast compartment of the marrow hematopoietic niche is vulnerable to functional dysregulation by damage imposed by agents frequently used in clinical settings. Understanding the mechanistic underpinning of chemotherapy-induced changes on the hematopoietic support capacity of the marrow microenvironment may contribute to improved strategies to optimize patient recovery post-transplantation.

  6. Improved dosimetry techniques for intravascular brachytherapy

    NASA Astrophysics Data System (ADS)

    Sehgal, Varun

    Coronary artery disease leads to the accumulation of atheromatous plaque leading to coronary stenosis. Coronary intervention techniques such as balloon angioplasty and atherectomy are used to address coronary stenosis and establish a stable lumen thus enhancing blood flow to the myocardium. Restenosis or re-blockage of the arteries is a major limitation of the above mentioned interventional techniques. Neointimal hyperplasia or proliferation of cells in response to the vascular injury as a result of coronary intervention is considered to be one of the major causes of restenosis. Recent studies indicated that irradiation of the coronary lesion site, with radiation doses ranging from 15 to 30 Gy, leads to diminishing neointimal hyperplasia with subsequent reduction in restenosis. The radiation dose is given by catheter-based radiation delivery systems using beta-emitters 90Sr/90Y, 32P and gamma-emitting 192Ir among others. However the dose schema used for dose prescription for these sources are relatively simplistic, and are based on calculations using uniform homogenous water or tissue media and simple cylinder geometry. Stenotic coronary vessels are invariably lined with atheromatous plaque of heterogeneous composition, the radiation dose distribution obtained from such dosimetry data can cause significant variations in the actual dose received by a given patient. Such discrepancies in dose calculation can introduce relatively large uncertainties in the limits of dose window for effective and safe application of intravascular brachytherapy, and consequently in the clinical evaluation of the efficacy of this modality. In this research study we investigated the effect of different geometrical and material heterogeneities, including residual plaque, catheter non-centering, lesion eccentricity and cardiac motion on the radiation dose delivered at the lesion site. Correction factors including dose perturbation factors and dose variation factors have been calculated

  7. Alfacalcidol increases cancellous bone in low turnover, fatty marrow sites in aged, orchidectomized rats.

    PubMed

    Tian, X Y; Chen, H Y; Setterberg, R B; Li, M; Jee, W S S

    2009-01-01

    The objectives of this study were to determine the responses of cancellous bone in the distal tibial metaphysis (DTM), a low turnover, fatty (yellow) marrow site, to sham-aged, orchidectomy (ORX) and alfacalcidol treatment in sham-aged and ORX rats. Eighteen-month-old male sham and ORX rats were treated with 0.1 and 0.2 microg/kg alfacalcidol 5 days/wk p.o. for 12 weeks, double fluorescent labeled, and the DTM were processed for bone histomorphometry analyses. The current study found the DTM in sham-aged male rats were resistant to age-related and ORX-induced cancellous bone loss and alfacalcidol-induced bone gain, findings that differ from that in the proximal tibial metaphysis (PTM) and lumbar vertebral body (LVB), two high turnover, red marrow bone sites. However, alfacalcidol treatment increased DTM bone mass in ORX rats where bone turnover was elevated by androgen deficiency. These results in concert with the previously positive findings in red marrow bone sites following alfacalcidol treatment suggest that alfacalcidol is more effective in increasing cancellous bone mass in the skeletal sites with higher bone turnover.

  8. Repair of orbital bone defects in canines using grafts of enriched autologous bone marrow stromal cells

    PubMed Central

    2014-01-01

    Backgroud Bone tissue engineering is a new approach for the repair of orbital defects. The aim of the present study was to explore the feasibility of tissue-engineered bone constructed using bone marrow stromal cells (BMSCs) that were rapidly isolated and concentrated from bone marrow (BM) by the red cell lysis method, then combined with β-tricalcium phosphate (β-TCP) to create grafts used to restore orbital bone defects in canines. Methods In the experimental group, grafts were constructed using BMSCs obtained by red cell lysis from 20 ml bone marrow, combined with β-TCP and BM via the custom-made stem cell-scaffold device, then used to repair 10 mm diameter medial orbital wall bony defects in canines. Results were compared with those in groups grafted with BM/β-TCP or β-TCP alone, or with defects left untreated as controls. The enrichment of BMSCs and nucleated cells (NCs) in the graft was calculated from the number in untreated bone marrow and in suspensions after red cell lysis. Spiral computed tomography (CT) scans were performed 1, 4, 12 and 24 weeks after implantation in all groups. Gross examination, micro-CT and histological measurements were performed 24 weeks after surgery. The results were analyzed to evaluate the efficacy of bone repair. Results The number of NCs and of colony-forming units within the scaffolds were increased 54.8 times and 53.4 times, respectively, compared with untreated bone marrow. In the BMSC-BM/β-TCP group, CT examination revealed that the scaffolds were gradually absorbed and the bony defects were restored. Micro-CT and histological examination confirmed that the implantations led to good repair of the defects, with 6 out 8 orbital defects completely restored in the experimental group, while by contrast, the grafts in the control groups did not fully repair the bony defects, a difference which was statistically significant (p < 0.05). Conclusions Tissue-engineered bone, constructed using BMSCs isolated by red cell

  9. Macroscopic to Microscopic Scales of Particulate Dosimetry: From Source to Fate in the Body

    EPA Science Inventory

    Additional perspective with regards to particle dosimetry is achieved by exploring dosimetry across a range of scales from macroscopic to microscopic in scope. Typically, one thinks of dosimetry as what happens when a particle is inhaled, where it is deposited, and how it is clea...

  10. Hanford External Dosimetry Technical Basis Manual PNL-MA-842

    SciTech Connect

    Rathbone, Bruce A.

    2007-03-12

    The Hanford External Dosimetry Technical Basis Manual PNL-MA-842 documents the design and implementation of the external dosimetry system used at Hanford. The manual describes the dosimeter design, processing protocols, dose calculation methodology, radiation fields encountered, dosimeter response characteristics, limitations of dosimeter design under field conditions, and makes recommendations for effective use of the dosimeters in the field. The manual describes the technical basis for the dosimetry system in a manner intended to help ensure defensibility of the dose of record at Hanford and to demonstrate compliance with 10 CFR 835, DOELAP, DOE-RL, ORP, PNSO, and Hanford contractor requirements. The dosimetry system is operated by PNNL’s Hanford External Dosimetry Program (HEDP) which provides dosimetry services to all Hanford contractors. The primary users of this manual are DOE and DOE contractors at Hanford using the dosimetry services of PNNL. Development and maintenance of this manual is funded directly by DOE and DOE contractors. Its contents have been reviewed and approved by DOE and DOE contractors at Hanford through the Hanford Personnel Dosimetry Advisory Committee (HPDAC) which is chartered and chaired by DOE-RL and serves as means of coordinating dosimetry practices across contractors at Hanford. This manual was established in 1996. Since inception, it has been revised many times and maintained by PNNL as a controlled document with controlled distribution. Rev. 0 marks the first revision to be released through PNNL’s Electronic Records & Information Capture Architecture (ERICA) database. Revision numbers that are whole numbers reflect major revisions typically involving changes to all chapters in the document. Revision numbers that include a decimal fraction reflect minor revisions, usually restricted to selected chapters or selected pages in the document. Revision Log: Rev. 0 (2/25/2005) Major revision and expansion. Rev. 0.1 (3/12/2007) Minor

  11. Hanford External Dosimetry Technical Basis Manual PNL-MA-842

    SciTech Connect

    Rathbone, Bruce A.

    2011-04-04

    The Hanford External Dosimetry Technical Basis Manual PNL-MA-842 documents the design and implementation of the external dosimetry system used at the U.S. Department of Energy (DOE) Hanford site. The manual describes the dosimeter design, processing protocols, dose calculation methodology, radiation fields encountered, dosimeter response characteristics, limitations of dosimeter design under field conditions, and makes recommendations for effective use of the dosimeters in the field. The manual describes the technical basis for the dosimetry system in a manner intended to help ensure defensibility of the dose of record at Hanford and to demonstrate compliance with requirements of 10 CFR 835, the DOE Laboratory Accreditation Program, the DOE Richland Operations Office, DOE Office of River Protection, DOE Pacific Northwest Office of Science, and Hanford’s DOE contractors. The dosimetry system is operated by the Pacific Northwest National Laboratory (PNNL) Hanford External Dosimetry Program which provides dosimetry services to PNNL and all Hanford contractors. The primary users of this manual are DOE and DOE contractors at Hanford using the dosimetry services of PNNL. Development and maintenance of this manual is funded directly by DOE and DOE contractors. Its contents have been reviewed and approved by DOE and DOE contractors at Hanford through the Hanford Personnel Dosimetry Advisory Committee which is chartered and chaired by DOE-RL and serves as means of coordinating dosimetry practices across contractors at Hanford. This manual was established in 1996. Since its inception, it has been revised many times and maintained by PNNL as a controlled document with controlled distribution. The first revision to be released through PNNL’s Electronic Records & Information Capture Architecture database was designated Revision 0. Revision numbers that are whole numbers reflect major revisions typically involving significant changes to all chapters in the document. Revision

  12. Hanford External Dosimetry Technical Basis Manual PNL-MA-842

    SciTech Connect

    Rathbone, Bruce A.

    2010-04-01

    The Hanford External Dosimetry Technical Basis Manual PNL-MA-842 documents the design and implementation of the external dosimetry system used at the U.S. Department of Energy (DOE) Hanford site. The manual describes the dosimeter design, processing protocols, dose calculation methodology, radiation fields encountered, dosimeter response characteristics, limitations of dosimeter design under field conditions, and makes recommendations for effective use of the dosimeters in the field. The manual describes the technical basis for the dosimetry system in a manner intended to help ensure defensibility of the dose of record at Hanford and to demonstrate compliance with requirements of 10 CFR 835, the DOE Laboratory Accreditation Program, the DOE Richland Operations Office, DOE Office of River Protection, DOE Pacific Northwest Office of Science, and Hanford’s DOE contractors. The dosimetry system is operated by the Pacific Northwest National Laboratory (PNNL) Hanford External Dosimetry Program which provides dosimetry services to PNNL and all Hanford contractors. The primary users of this manual are DOE and DOE contractors at Hanford using the dosimetry services of PNNL. Development and maintenance of this manual is funded directly by DOE and DOE contractors. Its contents have been reviewed and approved by DOE and DOE contractors at Hanford through the Hanford Personnel Dosimetry Advisory Committee which is chartered and chaired by DOE-RL and serves as means of coordinating dosimetry practices across contractors at Hanford. This manual was established in 1996. Since its inception, it has been revised many times and maintained by PNNL as a controlled document with controlled distribution. The first revision to be released through PNNL’s Electronic Records & Information Capture Architecture database was designated Revision 0. Revision numbers that are whole numbers reflect major revisions typically involving significant changes to all chapters in the document. Revision

  13. Clinical utility of flow cytometry in the study of erythropoiesis and nonclonal red cell disorders.

    PubMed

    Chesney, Alden; Good, David; Reis, Marciano

    2011-01-01

    Erythropoiesis involves proliferation and differentiation of small population of hematopoietic stem cells resident in the bone marrow into mature red blood cells. The determination of the cellular composition of the blood is a valuable tool in the diagnosis of diseases and monitoring of therapy. Flow cytometric analysis is increasingly being used to characterize the heterogeneous cell populations present in the blood and the hematopoietic cell differentiation and maturation pathways of the bone marrow. Here we discuss the role of flow cytometry in the study of erythropoiesis and nonclonal red blood cell disorders. First, we discuss flow cytometric analysis of reticulocytes. Next, we review salient quantitative methods that can be used for detection of fetal-maternal hemorrhage (FMH). We also discuss flow cytometric analysis of high hemoglobin F (HbF) in Sickle Cell Disease (SCD), hereditary spherocytosis (HS), red cell survival and red cell volume. We conclude by discussing cell cycle of erythroid cells.

  14. Student Perceptions of an Online Medical Dosimetry Program

    SciTech Connect

    Lenards, Nishele

    2011-07-01

    The University of Wisconsin-La Crosse offers the first online medical dosimetry program in the nation. There is no data to research a program of this type. This research consisted of the evaluation of other distance education programs including health profession programs in addition to face-to-face medical dosimetry programs. There was a need to collect and analyze student perceptions of online learning in medical dosimetry. This research provided a guide for future implementation by other programs as well as validated the University of Wisconsin-La Crosse program. Methodology used consisted of an electronic survey sent to all previous and currently enrolled students in the University of Wisconsin-La Crosse medical dosimetry program. The survey was both quantitative and qualitative in demonstrating attitudinal perceptions of students in the program. Quantitative data was collected and analyzed using a 5-point Likert scale. Qualitative data was gathered based on the open-ended responses and the identifying themes from the responses. The results demonstrated an overall satisfaction with this program, the instructor, and the online courses. Students felt a sense of belonging to the courses and the program. Considering that a majority of the students had never taken an online course previously, the students felt there were no technology issues. Future research should include an evaluation of board exam statistics for students enrolled in the online and face-to-face medical dosimetry programs.

  15. Characterization of the effect of MRI on Gafchromic film dosimetry.

    PubMed

    Reyhan, Meral L; Chen, Ting; Zhang, Miao

    2015-11-01

    Magnetic resonance (MR) imaging of Gafchromic film causes perturbation to absolute dosimetry measurements; the purpose of this work was to characterize the perturbation and develop a correction method for it. Three sets of Gafchromic EBT2 film were compared: radiation (control), radiation followed by MR imaging (RAD+B), and MR imaging followed by radiation (B+RAD). The T1-weighted and T2-weighted MR imaging was performed using a 1.5T scanner with the films wedged between two chicken legs. Doses from 0 to 800 cGy were delivered with a 6MV linac. The time interval between radiation and MR imaging was less than 10 min. Film calibration was generated from the red channel. Microscopic imaging was performed on two pieces of film. The effect of specific absorption rate (SAR) was determined by exposing another three sets of films to low, medium, and high levels of SAR through a series of pulse sequences. No discernible preferential alignment was detected on the microscopic images of the irradiated film exposed to MRI. No imaging artifacts were introduced by Gafchromic film on any MR images. On average, 4% dose difference was observed between B+RAD or RAD+B and the control, using the same calibration curve. The pixel values between the B+RAD or RAD+B and the control films were found to follow a linear relationship pixel(Control)=1.02×pixel(B+RAD or RAD+B). By applying this correction, the average dose error was reduced to approximately 2%. The SAR experiment revealed a dose overestimation with increasing SAR even when the correction was applied. It was concluded that MR imaging introduces perturbation on Gafchromic film dose measurements by 4% on average, compared to calibrating the film without the presence of MRI. This perturbation can be corrected by applying a linear correction to the pixel values. Additionally, Gafchromic film did not introduce any imaging artifacts in any of the MR images acquired. PACS number: 87.50.cm.

  16. Current personnel dosimetry practices at DOE facilities

    SciTech Connect

    Fix, J.J.

    1981-05-01

    Only three parameters were included in the personnel occupational exposure records by all facilities. These are employee name, social security number, and whole body dose. Approximate percentages of some other parameters included in the record systems are sex (50%), birthdate (90%), occupation (26%), previous employer radiation exposure (74%), etc. Statistical analysis of the data for such parameters as sex versus dose distribution, age versus dose distribution, cumulative lifetime dose, etc. was apparently seldom done. Less than 50% of the facilities reported having formal documentation for either the dosimeter, records system, or reader. Slightly greater than 50% of facilities reported having routine procedures in place. These are considered maximum percentages because some respondents considered computer codes as formal documentation. The repository receives data from DOE facilities regarding the (a) distribution of annual whole body doses, (b) significant internal depositions, and (c) individual doses upon termination. It is expected that numerous differences exist in the dose data submitted by the different facilities. Areas of significant differences would likely include the determination of non-measurable doses, the methods used to determine previous employer radiation dose, the methods of determining cumulative radiation dose, and assessment of internal doses. Undoubtedly, the accuracy of the different dosimetry systems, especially at low doses, is very important to the credibility of data summaries (e.g., man-rem) provided by the repository.

  17. Biological dosimetry in Russian and Italian astronauts

    NASA Astrophysics Data System (ADS)

    Greco, O.; Durante, M.; Gialanella, G.; Grossi, G.; Pugliese, M.; Scampoli, P.; Snigiryova, G.; Obe, G.

    Large uncertainties are associated with estimates of equivalent dose and cancer risk for crews of longterm space missions. Biological dosimetry in astronauts is emerging as a useful technique to compare predictions based on quality factors and risk coefficients with actual measurements of biological damage in-flight. In the present study, chromosomal aberrations were analyzed in one Italian and eight Russian cosmonauts following missions of different duration on the MIR and the international space station (ISS). We used the technique of fluorescence in situ hybridization (FISH) to visualize translocations in chromosomes 1 and 2. In some cases, an increase in chromosome damage was observed after flight, but no correlation could be found between chromosome damage and flight history, in terms of number of flights at the time of sampling, duration in space and extra-vehicular activity. Blood samples from one of the cosmonauts were exposed in vitro to 6 MeV X-rays both before and after the flight. An enhancement in radiosensitivity induced by the spaceflight was observed.

  18. Film Dosimetry for Intensity Modulated Radiation Therapy

    NASA Astrophysics Data System (ADS)

    Benites-Rengifo, J.; Martínez-Dávalos, A.; Celis, M.; Lárraga, J.

    2004-09-01

    Intensity Modulated Radiation Therapy (IMRT) is an oncology treatment technique that employs non-uniform beam intensities to deliver highly conformal radiation to the targets while minimizing doses to normal tissues and critical organs. A key element for a successful clinical implementation of IMRT is establishing a dosimetric verification process that can ensure that delivered doses are consistent with calculated ones for each patient. To this end we are developing a fast quality control procedure, based on film dosimetry techniques, to be applied to the 6 MV Novalis linear accelerator for IMRT of the Instituto Nacional de Neurología y Neurocirugía (INNN) in Mexico City. The procedure includes measurements of individual fluence maps for a limited number of fields and dose distributions in 3D using extended dose-range radiographic film. However, the film response to radiation might depend on depth, energy and field size, and therefore compromise the accuracy of measurements. In this work we present a study of the dependence of Kodak EDR2 film's response on the depth, field size and energy, compared with those of Kodak XV2 film. The first aim is to devise a fast and accurate method to determine the calibration curve of film (optical density vs. doses) commonly called a sensitometric curve. This was accomplished by using three types of irradiation techniques: Step-and-shoot, dynamic and static fields.

  19. Biological dosimetry by interphase chromosome painting

    NASA Technical Reports Server (NTRS)

    Durante, M.; George, K.; Yang, T. C.

    1996-01-01

    Both fluorescence in situ hybridization of metaphase spreads with whole-chromosome probes and premature chromosome condensation in interphase nuclei have been used in the past to estimate the radiation dose to lymphocytes. We combined these techniques to evaluate the feasibility of using painted interphase chromosomes for biodosimetry. Human peripheral lymphocytes were exposed to gamma rays and fused to mitotic Chinese hamster cells either immediately after irradiation or after 8 h incubation at 37 degrees C. Interphase or metaphase human chromosomes were hybridized with a composite probe specific for human chromosomes 3 and 4. The dose-response curve for fragment induction immediately after irradiation was linear; these results reflected breakage frequency in the total genome in terms of DNA content per chromosome. At 8 h after irradiation, the dose-response curve for chromosome interchanges, the prevalent aberration in interphase chromosomes, was linear-quadratic and similar to that observed for metaphase chromosomes. These results suggest that painting prematurely condensed chromosomes can be useful for biological dosimetry when blood samples are available shortly after the exposure, or when interphase cells are to be scored instead of mitotic cells.

  20. Mayak worker dosimetry study: An overview

    SciTech Connect

    Vasilenko, E. K.; Khokhryakov, V. F.; Miller, S C.; Fix, Jack J.; Eckerman, Keith F.; Choe, Dong Ok; Gorelov, Mikhail; Khokhryakov, Victor V.; Knyazev, V.; Krahenbuhl, Melinda P.; Scherpelz, Robert I.; Smetanin, Mikhail; Suslova, K. G.; Vostrotin, V.

    2007-09-01

    The Mayak Production Association (MPA) was the first plutonium production plant in the former Soviet Union. Workers at the MPA were exposed to relatively large internal radiation intakes and external radiation exposures, particularly in the early years of plant operations. This paper describes the updated dosimetry database, Doses-2005. Doses-2005 represents a significant improvement in the determination of absorbed organ dose from external radiation and plutonium intake for the original cohort of 18,831 Mayak workers. The methods of dose reconstruction of absorbed organ doses from external radiation uses: 1) archive records of measured dose and worker exposure history, 2) measured energy and directional response characteristics of historical Mayak film dosimeters, and 3) calculated dose conversion factors for Mayak Study-defined exposure scenarios using Monte Carlo techniques. The methods of dose reconstruction for plutonium intake uses two revised models developed from empirical data derived from bioassay and autopsy cases and/or updates from prevailing or emerging International Commission on Radiological Protection models. Other sources of potential significant exposure to workers such as medical diagnostic x-rays, ambient onsite external radiation, neutron radiation, intake of airborne effluent, and intake of nuclides other than plutonium were evaluated to determine their impact on the dose estimates.

  1. Calibration facility for environment dosimetry instruments

    NASA Astrophysics Data System (ADS)

    Bercea, Sorin; Celarel, Aurelia; Cenusa, Constantin

    2013-12-01

    In the last ten years, the nuclear activities, as well as the major nuclear events (see Fukushima accident) had an increasing impact on the environment, merely by contamination with radioactive materials. The most conferment way to quickly identify the presence of some radioactive elements in the environment, is to measure the dose-equivalent rate H. In this situation, information concerning the values of H due only to the natural radiation background must exist. Usually, the values of H due to the natural radiation background, are very low (˜10-9 - 10-8 Sv/h). A correct measurement of H in this range involve a performing calibration of the measuring instruments in the measuring range corresponding to the natural radiation background lead to important problems due to the presence of the natural background itself the best way to overlap this difficulty is to set up the calibration stand in an area with very low natural radiation background. In Romania, we identified an area with such special conditions at 200 m dept, in a salt mine. This paper deals with the necessary requirements for such a calibration facility, as well as with the calibration stand itself. The paper includes also, a description of the calibration stand (and images) as well as the radiological and metrological parameters. This calibration facilities for environment dosimetry is one of the few laboratories in this field in Europe.

  2. Optical dosimetry for interstitial photodynamic therapy

    SciTech Connect

    Arnfield, M.R.; Tulip, J.; Chetner, M.; McPhee, M.S. )

    1989-07-01

    An approach to photodynamic treatment of tumors is the interstitial implantation of fiber optic light sources. Dosimetry is critical in identifying regions of low light intensity in the tumor which may prevent tumor cure. We describe a numerical technique for calculating light distributions within tumors, from multiple fiber optic sources. The method was tested using four translucent plastic needles, which were placed in a 0.94 X 0.94 cm grid pattern within excised Dunning R3327-AT rat prostate tumors. A cylindrical diffusing fiber tip, illuminated by 630 nm dye laser light was placed within one needle and a miniature light detector was placed within another. The average penetration depth in the tumor region between the two needles was calculated from the optical power measured by the detector, using a modified diffusion theory. Repeating the procedure for each pair of needles revealed significant variations in penetration depth within individual tumors. Average values of penetration depth, absorption coefficient, scattering coefficient, and mean scattering cosine were 0.282 cm, 0.469 cm-1, 250 cm-1 and 0.964, respectively. Calculated light distributions from four cylindrical sources in tumors gave reasonable agreement with direct light measurements using fiber optic probes.

  3. Reactor dosimetry and RPV life management

    SciTech Connect

    Belousov, S.; Ilieva, K.; Mitev, M.

    2011-07-01

    Reactor dosimetry (RD) is a tool that provides data for neutron fluence accumulated over the reactor pressure vessel (RPV) during the reactor operation. This information, however, is not sufficient for RPV lifetime assessment. The life management of RPV is a multidisciplinary task. To assess whether the RPV steel properties at the current stage (for actual accumulated neutron fluence) of reactor operation are still 'safe enough,' the dependence of material properties on the fluence must be known; this is a task for material science (MS). Moreover, the mechanical loading over the RPV during normal operation and accidence have to be known, as well, for evaluation, if the RPV material integrity in this loading condition and existing cracks is provided. The crack loading path in terms of stress intensity factor is carried out by structural analyses (SA). Pressure and temperature distribution over RPV used in these analyses are obtained from a thermal hydraulic (TH) calculation. The conjunction of RD and other disciplines in RPV integrity assessment is analyzed in accordance with the FFP (fitness for purpose) approach. It could help to improve the efficiency in multi-disciplinary tasks solutions. (authors)

  4. Millimeter wave dosimetry of human skin.

    PubMed

    Alekseev, S I; Radzievsky, A A; Logani, M K; Ziskin, M C

    2008-01-01

    To identify the mechanisms of biological effects of mm waves it is important to develop accurate methods for evaluating absorption and penetration depth of mm waves in the epidermis and dermis. The main characteristics of mm wave skin dosimetry were calculated using a homogeneous unilayer model and two multilayer models of skin. These characteristics included reflection, power density (PD), penetration depth (delta), and specific absorption rate (SAR). The parameters of the models were found from fitting the models to the experimental data obtained from measurements of mm wave reflection from human skin. The forearm and palm data were used to model the skin with thin and thick stratum corneum (SC), respectively. The thin SC produced little influence on the interaction of mm waves with skin. On the contrary, the thick SC in the palm played the role of a matching layer and significantly reduced reflection. In addition, the palmar skin manifested a broad peak in reflection within the 83-277 GHz range. The viable epidermis plus dermis, containing a large amount of free water, greatly attenuated mm wave energy. Therefore, the deeper fat layer had little effect on the PD and SAR profiles. We observed the appearance of a moderate SAR peak in the therapeutic frequency range (42-62 GHz) within the skin at a depth of 0.3-0.4 mm. Millimeter waves penetrate into the human skin deep enough (delta = 0.65 mm at 42 GHz) to affect most skin structures located in the epidermis and dermis.

  5. Personnel real time dosimetry in interventional radiology.

    PubMed

    Servoli, L; Bissi, L; Fabiani, S; Magalotti, D; Placidi, P; Scorzoni, A; Calandra, A; Cicioni, R; Chiocchini, S; Dipilato, A C; Forini, N; Paolucci, M; Di Lorenzo, R; Cappotto, F P; Scarpignato, M; Maselli, A; Pentiricci, A

    2016-12-01

    Interventional radiology and hemodynamic procedures have rapidly grown in number in the past decade, increasing the importance of personnel dosimetry not only for patients but also for medical staff. The optimization of the absorbed dose during operations is one of the goals that fostered the development of real-time dosimetric systems. Indeed, introducing proper procedure optimization, like correlating dose rate measurements with medical staff position inside the operating room, the absorbed dose could be reduced. Real-time dose measurements would greatly facilitate this task through real-time monitoring and automatic data recording. Besides real-time dose monitoring could allow automatic data recording. In this work, we will describe the calibration and validation of a wireless real-time prototype dosimeter based on a new sensor device (CMOS imager). The validation measurement campaign in clinical conditions has demonstrated the prototype capability of measuring dose-rates with a frequency in the range of few Hz, and an uncertainty smaller than 10%.

  6. Dosimetry of in situ activated dysprosium microspheres.

    PubMed

    Adnani, N

    2004-03-07

    This paper presents the results of a study aimed at investigating the dosimetry of stable dysprosium microspheres activated, in situ, by a linac generated photon beam. In phantom measurements of the neutron flux within an 18 MV photon beam were performed using CR-39 detectors and gold activation. The results were used in conjunction with a Monte Carlo computer simulation to investigate the dose distribution resulting from the activation of dysprosium (Dy) microspheres using an 18 MV photon beam. Different depths, lesion volumes and volume concentrations of microspheres are investigated. The linac lower collimator jaws are assumed completely closed to shield the tumour volume from the photon dose. Using a single AP field with 0 x 0 cm2 field size (closed jaws), a photon dose rate of 600 MU min(-1) and 80 cm SSD for 10 min, an average dose exceeding 1 Gy can be delivered to spherical lesions of 0.5 cm and higher diameter. The variation of the average dose with the size of the lesion reaches saturation for tumour volumes exceeding 1 cm in diameter. This report shows that the photon beam of a high-energy linac can be used to activate Dy microspheres in situ and, as a result, deliver a significant dose of beta radiation. Non-radioactive Dy microspheres do not have the toxicity and imaging problems associated with commercially available yttrium-90 based products.

  7. Implementation of IMRT and VMAT using Delta4 phantom and portal dosimetry as dosimetry verification tools

    NASA Astrophysics Data System (ADS)

    Daci, Lulzime; Malkaj, Partizan

    2016-03-01

    In this study we analyzed and compared the dose distribution of different IMRT and VMAT plans with the intent to provide pre-treatment quality assurance using two different tools. Materials/Methods: We have used the electronic portal imaging device EPID after calibration to dose and correction for the background offset signal and also the Delta4 phantom after en evaluation of angular sensitivity. The Delta4 phantom has a two-dimensional array with ionization chambers. We analyzed three plans for each anatomical site calculated by Eclipse treatment planning system. The measurements were analyzed using γ-evaluation method with passing criteria 3% absolute dose and 3 mm distance to agreement (DTA). For all the plans the range of score has been from 97% to 99% for gantry fixed at 0° while for rotational planes there was a slightly decreased pass rates and above 95%. Point measurement with a ionization chamber were done in additional to see the accuracy of portal dosimetry and to evaluate the Delta4 device to various dose rates. Conclusions: Both Delt4 and Portal dosimetry shows good results between the measured and calculated doses. While Delta4 is more accurate in measurements EPID is more time efficient. We have decided to use both methods in the first steps of IMRT and VMAT implementation and later on to decide which of the tools to use depending on the complexity of plans, how much accurate we want to be and the time we have on the machine.

  8. [Changes in the bone marrow in cancer patients. 61 bone marrow biopsies].

    PubMed

    Marsan, C; Henon, P; Cywiner-Golenzer, C; Zitouna, M M; Girardi, P

    1976-01-01

    The authors studied 61 bone marrow biopsies carried out in cancerous patients, presumably suffering from a bone metastasis and before any treatment. They feel that quantitative and qualitative changes in the bone marrow may be considered to be an indirect diagnostic indication of metastatic spread.

  9. Marrow stromal fibroblastic cell cultivation in vitro on decellularized bone marrow extracellular matrix.

    PubMed

    Dutra, Timothy F; French, Samuel W

    2010-02-01

    The in vitro biocompatibility of decellularized bone marrow extracellular matrix was evaluated. Following a freeze-thaw cycle, sectioned discs of fresh frozen rat metaphyseal bone were sequentially incubated in solutions of hypertonic, then hypotonic Ringer's solution, followed by deoxycholic acid, then DNAase I. The adequacy of decellularization of marrow stroma was examined by light microscopy. Marrow stromal fibroblastic cells were harvested by dispersion of rat long bone marrow, followed by concentration by discontinuous Ficoll-Paque gradient centrifugation. The fibroblastic cells were expanded by in vitro cultivation, and second passage cells were cryopreserved until needed. Cryopreserved marrow stromal cells were applied dropwise to sections of decellularized bone marrow extracellular matrix, and cultured in BJGb medium with 20% fetal bovine serum for ten days. Mature cultures were formalin fixed, decalcified, and embedded in paraffin. Light microscopy of hematoxylin and eosin stained sections showed individual spindle cells invading the upper portion of the decellularized extracellular matrix, and also a monolayer of spindle cells on the upper surfaces of exposed trabecular and cortical bone. This experiment showed that decellularized marrow extracellular matrix is a biocompatible three dimensional in vitro substrate for marrow stromal fibroblastic cells.

  10. Patterns of patient specific dosimetry in total body irradiation

    SciTech Connect

    Akino, Yuichi; McMullen, Kevin P.; Das, Indra J.

    2013-04-15

    Purpose: Total body irradiation (TBI) has been used for bone marrow transplant for hematologic and immune deficiency conditions. The goal of TBI is to deliver a homogeneous dose to the entire body, with a generally accepted range of dose uniformity being within {+-}10% of the prescribed dose. The moving table technique for TBI could make dose uniform in whole body by adjusting couch speed. However, it is difficult to accurately estimate the actual dose by calculation and hence in vivo dosimetry (IVD) is routinely performed. Here, the authors present patterns of patient-specific IVD in 161 TBI patients treated at our institution. Methods: Cobalt-60 teletherapy unit (Model C9 Cobalt-60 teletherapy unit, Picker X-ray Corporation) with customized moving bed (SITI Industrial Products, Inc., Fishers, IN) were used for TBI treatment. During treatment, OneDose{sup TM} (Sicel Technology, NC) Metal Oxide-silicon Semiconductor Field Effect Transistor detectors were placed at patient body surface; both entrance and exit side of the beam at patient head, neck, mediastinum, umbilicus, and knee to estimate midplane dose. When large differences (>10%) between the prescribed and measured dose were observed, dose delivery was corrected for subsequent fractions by the adjustment of couch speed and/or bolus placement. Under IRB exempt status, the authors retrospectively analyzed the treatment records of 161 patients who received TBI treatment between 2006 and 2011. Results: Across the entire cohort, the median {+-} SD (range) percent variance between calculated and measured dose for head, neck, mediastinum, umbilicus, and knee was -2.3 {+-} 10.2% (-66.2 to +35.3), 1.1 {+-} 11.5% (-62.2 to +40.3), -1.9 {+-} 9.5% (-66.4 to +46.6), -1.1 {+-} 7.2% (-35.2 to +42.9), and 3.4 {+-} 12.2% (-47.9 to +108.5), respectively. More than half of treatments were within {+-}10% of the prescribed dose for all anatomical regions. For 80% of treatments (10%-90%), dose at the umbilicus was within {+-}10

  11. Magnetic resonance imaging of bone marrow disease in children

    SciTech Connect

    Cohen, M.D.; Klatte, E.C.; Baehner, R.; Smith, J.A.; Martin-Simmerman, P.; Carr, B.E.; Provisor, A.J.; Weetman, R.M.; Coates, T.; Siddiqui, A.

    1984-06-01

    Seven children underwent magnetic resonance imaging (MRI) of the bone marrow: results showed that it is technically feasible to obtain good MR images of marrow in children. MR has detected abnormality in the bone marrow of a child who had metastatic neuroblastoma. The extent of abnormality in the femur correlated well with findings of a bone marrow isotope scan. In one child who had idiopathic aplastic anemia, diseased marrow could not be distinguished from normal marrow on MR images. MRI identified abnormality of the marrow in osteogenic sarcoma, and demonstrated change in response to chemotherapy. It displayed marrow spread of tumors as well as CT. MRI showed marrow abnormality in four children who had leukemia.

  12. A Comparison of Singlet Oxygen Explicit Dosimetry (SOED) and Singlet Oxygen Luminescence Dosimetry (SOLD) for Photofrin-Mediated Photodynamic Therapy

    PubMed Central

    Kim, Michele M.; Penjweini, Rozhin; Gemmell, Nathan R.; Veilleux, Israel; McCarthy, Aongus; Buller, Gerald S.; Hadfield, Robert H.; Wilson, Brian C.; Zhu, Timothy C.

    2016-01-01

    Accurate photodynamic therapy (PDT) dosimetry is critical for the use of PDT in the treatment of malignant and nonmalignant localized diseases. A singlet oxygen explicit dosimetry (SOED) model has been developed for in vivo purposes. It involves the measurement of the key components in PDT—light fluence (rate), photosensitizer concentration, and ground-state oxygen concentration ([3O2])—to calculate the amount of reacted singlet oxygen ([1O2]rx), the main cytotoxic component in type II PDT. Experiments were performed in phantoms with the photosensitizer Photofrin and in solution using phosphorescence-based singlet oxygen luminescence dosimetry (SOLD) to validate the SOED model. Oxygen concentration and photosensitizer photobleaching versus time were measured during PDT, along with direct SOLD measurements of singlet oxygen and triplet state lifetime (τΔ and τt), for various photosensitizer concentrations to determine necessary photophysical parameters. SOLD-determined cumulative [1O2]rx was compared to SOED-calculated [1O2]rx for various photosensitizer concentrations to show a clear correlation between the two methods. This illustrates that explicit dosimetry can be used when phosphorescence-based dosimetry is not feasible. Using SOED modeling, we have also shown evidence that SOLD-measured [1O2]rx using a 523 nm pulsed laser can be used to correlate to singlet oxygen generated by a 630 nm laser during a clinical malignant pleural mesothelioma (MPM) PDT protocol by using a conversion formula. PMID:27929427

  13. Morphologic, biochemical, and cytogenetic studies of bone marrow and circulating blood cells in painters exposed to ethylene glycol ethers.

    PubMed

    Cullen, M R; Solomon, L R; Pace, P E; Buckley, P; Duffy, T P; McPhedran, P; Kelsey, K T; Redlich, C A

    1992-10-01

    In a previous cross-sectional survey, up to 15% of shipyard painters were found to have mild anemia or granulocytopenia, mostly acquired since employment. Environmental studies had suggested a possible etiologic role for ethylene glycol ethers, solvents to which the men were heavily exposed and which have established myelotoxic potential. To exclude alternative hypotheses, examine possible common patterns of injury, and identify potential risk factors and markers for such an effect, the affected painters were further studied. The painters were matched with two groups of controls: exposed painters without evidence of hematologic abnormality on the previous survey and unexposed controls. Altogether 25 subjects were studied by histopathologic examination of bone marrow, cytogenetic studies of marrow cells, and peripheral lymphocytes and peripheral red cell studies of membrane and metabolic function. Except for an unexpected finding of a race-associated effect on marrow histology, insignificant differences were seen among the groups in terms of marrow morphology and cellularity, stem cell growth kinetics, and marrow or peripheral cytogenetics. Two metabolic abnormalities of peripheral red cells related to exposure or clinical status of the subjects were found. Pyruvate kinase, an established marker of acquired myelodysplasia, was significantly depressed in the subjects with previously abnormal counts. Although reduced glutathione levels and holoenzyme activities of glutathione reductase (GSHR) did not differ among groups, exposed subjects had decreased saturation of GSHR with flavin adenine dinucleotide which could be restored in vitro, suggesting riboflavin deficiency or impaired riboflavin metabolism. Thus, although a unique pattern of bone marrow injury by histologic or genetic assay attributable to ethylene glycol ethers was not defined, biochemical effects of possible mechanistic importance were identified. The relevance of these findings as subclinical disease

  14. A transferability study of the EPR-tooth-dosimetry technique.

    PubMed

    Sholom, S; Chumak, V; Desrosiers, M; Bouville, A

    2006-01-01

    The transferability of a measurement protocol from one laboratory to another is an important feature of any mature, standardised protocol. The electron paramagnetic resonance (EPR)-tooth dosimetry technique that was developed in Scientific Center for Radiation Medicine, AMS, Ukraine (SCRM) for routine dosimetry of Chernobyl liquidators has demonstrated consistent results in several inter-laboratory measurement comparisons. Transferability to the EPR dosimetry laboratory at the National Institute of Standards and Technology (NIST) was examined. Several approaches were used to test the technique, including dose reconstruction of SCRM-NIST inter-comparison samples. The study has demonstrated full transferability of the technique and the possibility to reproduce results in a different laboratory environment.

  15. Report from the dosimetry working group to CEDR project management

    SciTech Connect

    Fix, J J

    1994-08-01

    On August 2, 1989, Admiral Watkins, Secretary of the US Department of Energy (DOE), presented a four-point program designed to enhance the DOE epidemiology program. One part of this program was the establishment of a Comprehensive Epidemiologic Data Resource (CEDR) to facilitate independent research to validate and supplement DOE research on human health effects. A Dosimetry Working Group was formed during May 1991 to evaluate radiation dose variables and associated documentation that would be most useful to researchers for retrospective and prospective studies. The Working Group consisted of thirteen individuals with expertise and experience in health physics, epidemiology, dosimetry, computing, and industrial hygiene. A final report was delivered to CEDR Project Management during February 1992. The report contains a number of major recommendations concerning collection, interpretation, and documentation of dosimetry data to maximize their usefulness to researchers using CEDR for examining possible health effects of occupational exposure to ionizing radiation.

  16. Optical-CT gel-dosimetry I: basic investigations.

    PubMed

    Oldham, Mark; Siewerdsen, Jeffrey H; Kumar, Sai; Wong, John; Jaffray, David A

    2003-04-01

    Comprehensive verification of the intricate dose distributions associated with advanced radiation treatments is now an immediate and substantial problem. The task is challenging using traditional dosimeters because of restrictions to point measurements (ion chambers, diodes, TLD, etc.) or planar measurements (film). In essence, rapid advances in the technology to deliver radiation treatments have not been paralleled by corresponding advances in the ability to verify these treatments. A potential solution has emerged in the form of water equivalent three dimensional (3D) gel-dosimetry. In this paper we present basic characterization and performance studies of a prototype optical-CT scanning system developed in our laboratory. An analysis of the potential role or scope of gel dosimetry, in relation to other dosimeters, and to verification across the spectrum of therapeutic techniques is also given. The characterization studies enabled the determination of nominal operating conditions for optical-CT scanning. "Finger" phantoms are introduced as a powerful and flexible tool for the investigation of optical-CT performance. The modulation-transfer function (MTF) of the system is determined to be better than 10% out to 1 mm(-1), confirming sub-mm imaging ability. System performance is demonstrated by the acquisition of a 1 x 1 x 1 mm3 dataset through the dose distribution delivered by an x-ray lens that focuses x rays in the energy range 40-80 KeV. This 3D measurement would be extremely difficult to achieve with other dosimetry techniques and highlights some of the strengths of gel dosimetry. Finally, an optical Monte Carlo model is introduced and shown to have potential to model light transport through gel-dosimetry systems, and to provide a tool for the study and optimization of optical-CT gel dosimetry. The model utilizes Mie scattering theory and requires knowledge of the variation of the particle size distribution with dose. The latter was determined here using the

  17. Treatment with a sclerostin antibody increases cancellous bone formation and bone mass regardless of marrow composition in adult female rats.

    PubMed

    Tian, XiaoYan; Setterberg, Rebecca B; Li, Xiaodong; Paszty, Chris; Ke, Hua Zhu; Jee, Webster S S

    2010-09-01

    The current report describes the skeletal effects of a sclerostin monoclonal antibody (Scl-AbIII) treatment at a yellow (fatty) marrow skeletal site in adult female rats. Ten-month-old female Sprague-Dawley rats were treated with vehicle or Scl-AbIII at 5 or 25 mg/kg, twice per week by s.c. injection for 4 weeks. Trabecular bone from a yellow (fatty) marrow site, the 5th caudal vertebral body (CVB), was processed undecalcified for quantitative bone histomorphometric analysis. Compared to vehicle controls, Scl-AbIII at both doses significantly increased bone formation parameters and trabecular bone volume and thickness and decreased bone resorption parameter in the trabecular bone of the CVB. As a reference, we also found that the Scl-AbIII at both doses significantly decreased bone resorption and increased bone formation and bone volume in a red (hematopoietic) marrow site, the 4th lumber vertebral body (LVB). It appears that the percentage of increase in trabecular bone volume induced by Scl-AbIII treatment was slightly larger in the LVB than in the CVB. In summary, these preclinical findings show that antibody-mediated sclerostin inhibition has significant bone anabolic effects at both red and yellow marrow skeletal sites.

  18. Faraday cup: absolute dosimetry for ELIMED beam line

    NASA Astrophysics Data System (ADS)

    Leanza, R.; Romano, F.; Scuderi, V.; Amico, A. G.; Cuttone, G.; Larosa, G.; Margarone, D.; Milluzzo, G.; Petringa, G.; Pipek, J.; Schillaci, F.; Cirrone, G. A. P.

    2017-03-01

    The scientific community has shown a growing interest towards multidisciplinary applications of laser-driven beams. In this framework, the ELIMED (ELI-Beamlines MEDical and multidisciplinary applications) beamline will be the first transport beamline dedicated to the medical and multidisciplinary studies with laser-accelerated ion beams. Detectors for dosimetry represent one of key-element of the ELIMED beamline, allowing a dose delivering with good result as required in the clinical applications. In this contribution, a Faraday Cup for absolute dosimetry, designed and realized at INFN-LNS, is described.

  19. Current state of the art brachytherapy treatment planning dosimetry algorithms

    PubMed Central

    Pantelis, E; Karaiskos, P

    2014-01-01

    Following literature contributions delineating the deficiencies introduced by the approximations of conventional brachytherapy dosimetry, different model-based dosimetry algorithms have been incorporated into commercial systems for 192Ir brachytherapy treatment planning. The calculation settings of these algorithms are pre-configured according to criteria established by their developers for optimizing computation speed vs accuracy. Their clinical use is hence straightforward. A basic understanding of these algorithms and their limitations is essential, however, for commissioning; detecting differences from conventional algorithms; explaining their origin; assessing their impact; and maintaining global uniformity of clinical practice. PMID:25027247

  20. Third conference on radiation protection and dosimetry. Program and abstracts

    SciTech Connect

    1991-01-01

    This conference has been designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection and providing them with sufficient information to evaluate their programs. To partly fulfill these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection has been prepared. General topics include external dosimetry, internal dosimetry, instruments, regulations and standards, accreditation and test programs, research advances, and applied program experience. This publication provides a summary of the technical program and a collection of abstracts of the oral presentations.

  1. Hanford Internal Dosimetry Program Manual, PNL-MA-552

    SciTech Connect

    Carbaugh, Eugene H.; Bihl, Donald E.; Maclellan, Jay A.

    2009-09-24

    This manual is a guide to the services provided by the Hanford Internal Dosimetry Program (IDP), which is operated by the Pacific Northwest National Laboratory.( ) for the U.S. Department of Energy Richland Operations Office, Office of River Protection and their Hanford Site contractors. The manual describes the roles of and relationships between the IDP and the radiation protection programs of the Hanford Site contractors. Recommendations and guidance are also provided for consideration in implementing bioassay monitoring and internal dosimetry elements of radiation protection programs.

  2. The use of a portable electronic device in accident dosimetry.

    PubMed

    Beerten, Koen; Vanhavere, Filip

    2008-01-01

    The use of a portable electronic device in accident dosimetry has been investigated. The thermoluminescence properties of a surface-mount alumina-rich ceramic resonator from a USB flash drive were investigated. The following characteristics were verified: the absence of a zero-dose signal, gamma dose response, dose recycling behaviour, fading and optical bleaching. Finally, this component has been successfully used to determine a simulated accident dose (1 d following the irradiation event). It is concluded that it should be possible to perform rapid and reliable accident dose assessments with such components using conventional thermoluminescence dosimetry equipment.

  3. Abnormal bone marrow histopathology in paediatric mastocytosis.

    PubMed

    Carter, Melody C; Metcalfe, Dean D; Clark, Alicia S; Wayne, Alan S; Maric, Irina

    2015-03-01

    The diagnostic criteria for paediatric mastocytosis are largely based on adult studies and bone marrow findings are not well described in children. We evaluated use of the World Health Organization (WHO) criteria for the diagnosis of systemic disease in paediatric mastocytosis. In addition, we identified unique clinico-histopathological features within the biopsies. One hundred and thirteen children with paediatric mastocytosis were evaluated at the National Institutes of Health between 1986 and 2013. Complete bone marrow evaluations were performed in 50 cases. Seven children had repeat procedures. Bone marrows were analysed by histopathology, flow cytometry and for KIT D816V. Bone marrow biopsies displayed mild atypical haematopoietic maturation, increased haematogones and hypocellularity in a sub-set of patients with urticaria pigmentosa, diffuse cutaneous mastocytosis and indolent systemic mastocytosis. Hypocellularity was most pronounced in those with urticaria pigmentosa. Haematogones were highest, on average, in patients with diffuse cutaneous mastocytosis or mastocytomas. There was no evidence of peripheral blood cytopenias, myelodysplastic syndrome, myeloproliferative neoplasm or leukaemia within this cohort. The WHO criteria are applicable for the diagnosis of systemic mastocytosis in paediatrics. Although unsuspected bone marrow findings typically seen in myeloproliferative disorders are frequent in paediatric mastocytosis, patients within this study remained clinically stable without progression to a more aggressive variant.

  4. Radionuclide imaging of bone marrow disorders.

    PubMed

    Agool, Ali; Glaudemans, Andor W J M; Boersma, Hendrikus H; Dierckx, Rudi A J O; Vellenga, Edo; Slart, Riemer H J A

    2011-01-01

    Noninvasive imaging techniques have been used in the past for visualization the functional activity of the bone marrow compartment. Imaging with radiolabelled compounds may allow different bone marrow disorders to be distinguished. These imaging techniques, almost all of which use radionuclide-labelled tracers, such as (99m)Tc-nanocolloid, (99m)Tc-sulphur colloid, (111)In-chloride, and radiolabelled white blood cells, have been used in nuclear medicine for several decades. With these techniques three separate compartments can be recognized including the reticuloendothelial system, the erythroid compartment and the myeloid compartment. Recent developments in research and the clinical use of PET tracers have made possible the analysis of additional properties such as cellular metabolism and proliferative activity, using (18)F-FDG and (18)F-FLT. These tracers may lead to better quantification and targeting of different cell systems in the bone marrow. In this review the imaging of different bone marrow targets with radionuclides including PET tracers in various bone marrow diseases are discussed.

  5. Tracking Mouse Bone Marrow Monocytes In Vivo

    PubMed Central

    Hamon, Pauline; Rodero, Mathieu Paul; Combadière, Christophe; Boissonnas, Alexandre

    2015-01-01

    Real time multiphoton imaging provides a great opportunity to study cell trafficking and cell-to-cell interactions in their physiological 3-dimensionnal environment. Biological activities of immune cells mainly rely on their motility capacities. Blood monocytes have short half-life in the bloodstream; they originate in the bone marrow and are constitutively released from it. In inflammatory condition, this process is enhanced, leading to blood monocytosis and subsequent infiltration of the peripheral inflammatory tissues. Identifying the biomechanical events controlling monocyte trafficking from the bone marrow towards the vascular network is an important step to understand monocyte physiopathological relevance. We performed in vivo time-lapse imaging by two-photon microscopy of the skull bone marrow of the Csf1r-Gal4VP16/UAS-ECFP (MacBlue) mouse. The MacBlue mouse expresses the fluorescent reporters enhanced cyan fluorescent protein (ECFP) under the control of a myeloid specific promoter 1, in combination with vascular network labelling. We describe how this approach enables the tracking of individual medullar monocytes in real time to further quantify the migratory behaviour within the bone marrow parenchyma and the vasculature, as well as cell-to-cell interactions. This approach provides novel insights into the biology of the bone marrow monocyte subsets and allows to further address how these cells can be influenced in specific pathological conditions. PMID:25867540

  6. SU-E-QI-15: Single Point Dosimetry by Means of Cerenkov Radiation Energy Transfer (CRET)

    SciTech Connect

    Volotskova, O; Jenkins, C; Xing, L

    2014-06-15

    Purpose: Cerenkov light is generated when a charged particles with energy greater then 250 keV, moves faster than the speed of light in a given medium. Both x-ray photons and electrons produce optical Cerenkov photons during the static megavoltage linear accelerator (LINAC) operational mode. Recently, Cerenkov radiation gained considerable interest as possible candidate as a new imaging modality. Optical signals generated by Cerenkov radiation may act as a surrogate for the absorbed superficial radiation dose. We demonstrated a novel single point dosimetry method for megavoltage photon and electron therapy utilizing down conversion of Cerenkov photons. Methods: The custom build signal characterization system was used: a sample holder (probe) with adjacent light tight compartments was connected via fiber-optic cables to a photon counting photomultiplier tube (PMT). One compartment contains a medium only while the other contains medium and red-shifting nano-particles (Q-dots, nanoclusters). By taking the difference between the two signals (Cerenkov photons and CRET photons) we obtain a measure of the down-converted light, which we expect to be proportional to dose as measured with an adjacent ion chamber. Experimental results are compared to Monte Carlo simulations performed using the GEANT4 code. Results: The signal correlation between CR signal, CRET readings and dose produced by LINAC at a single point were investigated. The experimental results were compared with simulations. The dose linearity, signal to noise ratio and dose rate dependence were tested with custom build CRET based probe. Conclusion: Performance characteristics of the proposed single point CRET based probe were evaluated. The direct use of the induced Cerenkov emission and CRET in an irradiated single point volume as an indirect surrogate for the imparted dose was investigated. We conclude that CRET is a promising optical based dosimetry method that offers advantages over those already proposed.

  7. Tenth ORNL Personnel Dosimetry Intercomparison Study

    SciTech Connect

    Swaja, R.E.; Chou, T.L.; Sims, C.S.; Greene, R.T.

    1985-03-01

    The Tenth Personnel Dosimetry Intercomparison Study was conducted at the Oak Ridge National Laboratory during April 9-11, 1984. Dosemeter badges from 31 participating organizations were mounted on 40cm Lucite phantoms and exposed to a range of dose equivalents which could be encountered during routine personnel monitoring in mixed radiation fields. The Health Physics Research Reactor served as the only source of radiation for eight of the ten irradiations which included a low (approx. 0.50 mSv) and high (approx. 10.00 mSv) neutron dose equivalent run for each of four shield conditions. Two irradiations were also conducted for which concrete- and Lucite-shield reactor irradiations were gamma-enhanced using a /sup 137/Cs source. Results indicated that some participants had difficulty obtaining measurable indication of neutron and gamma exposures at dose equivalents less than about 0.50 mSv and 0.20 mSv, respectively. Albedo dosemeters provided the best overall accuracy and precision for the neutron measurements. Direct interaction TLD systems showed significant variation in accuracy with incident spectrum, and threshold neutron dosemeters (film and recoil track) underestimated reference values by more than 50%. Gamma dose equivalents estimated in the mixed fields were higher than reference values with TL gamma dosemeters generally yielding more accurate results than film. Under the conditions of this study in which participants had information concerning exposure conditions and radiation field characteristics prior to dosemeter evaluation, only slightly more than half of all reported results met regulatory standards for neutron and gamma accuracy. 19 refs., 2 figs., 29 tabs.

  8. Subwavelength films for standoff radiation dosimetry

    NASA Astrophysics Data System (ADS)

    Alvine, Kyle J.; Bernacki, Bruce E.; Bennett, Wendy D.; Schemer-Kohrn, Alan; Suter, Jonathan D.

    2015-05-01

    We present optical subwavelength nanostructure architecture suitable for standoff radiation dosimetry with remote optical readout in the visible or infrared spectral regions. To achieve this, films of subwavelength structures are fabricated over several square inches via the creation of a 2D non-close packed (NCP) array template of radiationsensitive polymeric nanoparticles, followed by magnetron sputtering of a metallic coating to form a 2D array of separated hemispherical nanoscale metallic shells. The nanoshells are highly reflective at resonance in the visible or infrared depending on design. These structures and their behavior are based on the open ring resonator (ORR) architecture and have their analog in resonant inductive-capacitive (LC) circuits, which display a resonance wavelength that is inversely proportional to the square root of the product of the inductance and capacitance. Therefore, any modification of the nanostructure material properties due to radiation alters the inductive or capacitive behavior of the subwavelength features, which in turn changes their optical properties resulting in a shift in the optical resonance. This shift in resonance may be remotely interrogated actively using either laser illumination or passively by hyperspectral or multispectral sensing with broadband illumination. These structures may be designed to be either anisotropic or isotropic, which can also offer polarization-sensitive interrogation. We present experimental measurements of a radiation induced shift in the optical resonance of a subwavelength film after exposure to an absorbed dose of gamma radiation from 2 Mrad up to 62 Mrad demonstrating the effect. Interestingly the resonance shift is non-monotonic for this material system and possible radiation damage mechanisms to the nanoparticles are discussed.

  9. Activities at the NEA for Dosimetry Applications

    NASA Astrophysics Data System (ADS)

    Henriksson, H.; Kodeli, I.

    2009-08-01

    The Nuclear Energy Agency (NEA) is a specialised agency within the Organisation for Economic Co-operation and Development (OECD) that assists its member countries in maintaining and further developing, through international co-operation, the scientific and technological use of nuclear energy for peaceful purposes. The main role of the NEA is the collection, validation and distribution of basic nuclear data, computer codes covering the areas of nuclear research and engineering, and experimental data. The activities linked to dosimetry applications are described in this paper, such as those of the Working Party on international nuclear data Evaluation Co-operation (WPEC) established at the NEA to promote the exchange of nuclear data evaluations, measurements, nuclear model calculations and validation. Collection, validation, and distribution of the computer codes and nuclear data libraries will be presented and, in particular, the Joint Evaluated Fusion and Fission (JEFF) library project. For the verification of activation and transport nuclear data, as well as computational methods, several integral experimental databases are collected and distributed by the Data Bank, for example the Shielding Integral Benchmark Archive Database (SINBAD), the International Criticality Safety Benchmark Experiments Project (ICSBEP) and the International Reactor Physics Experiments (IRPhE). Another important activity at the NEA is the collection of experimental differential nuclear reaction data for the EXFOR database. A recent WPEC project emphasizes the need for a coherent format that could be used for computer code calculations and improved validation of experimental data. JANIS is a graphical visualization tool that has been found to be useful for checking the content of EXFOR.

  10. Subwavelength films for standoff radiation dosimetry

    SciTech Connect

    Alvine, Kyle J.; Bernacki, Bruce E.; Bennett, Wendy D.; Schemer-Kohrn, Alan L.; Suter, Jonathan D.

    2015-05-22

    We present optical subwavelength nanostructure architecture suitable for standoff radiation dosimetry with remote optical readout in the visible or infrared spectral regions. To achieve this, films of subwavelength structures are fabricated over several square inches via the creation of a 2D non-close packed (NCP) array template of radiation-sensitive polymeric nanoparticles, followed by magnetron sputtering of a metallic coating to form a 2D array of separated hemispherical nanoscale metallic shells. The nanoshells are highly reflective at resonance in the visible or infrared depending on design. These structures and their behavior are based on the open ring resonator (ORR) architecture and have their analog in resonant inductive-capacitive (LC) circuits, which display a resonance wavelength that is inversely proportional to the square root of the product of the inductance and capacitance. Therefore, any modification of the nanostructure material properties due to radiation alters the inductive or capacitive behavior of the subwavelength features, which in turn changes their optical properties resulting in a shift in the optical resonance. This shift in resonance may be remotely interrogated actively using either laser illumination or passively by hyperspectral or multispectral sensing with broadband illumination. These structures may be designed to be either anisotropic or isotropic, which can also offer polarization-sensitive interrogation. We present experimental measurements of a radiation induced shift in the optical resonance of a subwavelength film after exposure to an absorbed dose of gamma radiation from 2 Mrad up to 62 Mrad demonstrating the effect. Interestingly the resonance shift is non-monotonic for this material system and possible radiation damage mechanisms to the nanoparticles are discussed.

  11. Leptin-receptor-expressing mesenchymal stromal cells represent the main source of bone formed by adult bone marrow.

    PubMed

    Zhou, Bo O; Yue, Rui; Murphy, Malea M; Peyer, James G; Morrison, Sean J

    2014-08-07

    Studies of the identity and physiological function of mesenchymal stromal cells (MSCs) have been hampered by a lack of markers that permit both prospective identification and fate mapping in vivo. We found that Leptin Receptor (LepR) is a marker that highly enriches bone marrow MSCs. Approximately 0.3% of bone marrow cells were LepR(+), 10% of which were CFU-Fs, accounting for 94% of bone marrow CFU-Fs. LepR(+) cells formed bone, cartilage, and adipocytes in culture and upon transplantation in vivo. LepR(+) cells were Scf-GFP(+), Cxcl12-DsRed(high), and Nestin-GFP(low), markers which also highly enriched CFU-Fs, but negative for Nestin-CreER and NG2-CreER, markers which were unlikely to be found in CFU-Fs. Fate-mapping showed that LepR(+) cells arose postnatally and gave rise to most bone and adipocytes formed in adult bone marrow, including bone regenerated after irradiation or fracture. LepR(+) cells were quiescent, but they proliferated after injury. Therefore, LepR(+) cells are the major source of bone and adipocytes in adult bone marrow.

  12. Bone marrow blood vessel ossification and "microvascular dead space" in rat and human long bone.

    PubMed

    Prisby, Rhonda D

    2014-07-01

    Severe calcification of the bone microvascular network was observed in rats, whereby the bone marrow blood vessels appeared ossified. This study sought to characterize the magnitude of ossification in relation to patent blood vessels and adipocyte content in femoral diaphyses. Additionally, this study confirmed the presence of ossified vessels in patients with arteriosclerotic vascular disease and peripheral vascular disease and cellulitis. Young (4-6 month; n=8) and old (22-24 month; n=8) male Fischer-344 rats were perfused with barium sulfate to visualize patent bone marrow blood vessels. Femoral shafts were processed for bone histomorphometry to quantify ossified (Goldner's Trichrome) and calcified (Alizarin Red) vessels. Adipocyte content was also determined. Additional femora (n=5/age group) were scanned via μCT to quantify microvascular ossification. Bone marrow blood vessels from the rats and the human patients were also isolated and examined via microscopy. Ossified vessels (rats and humans) had osteocyte lacunae on the vessel surfaces and "normal" vessels were transitioning into bone. The volume of ossified vessels was 4800% higher (p<0.05) in the old vs. young rats. Calcified and ossified vessel volumes per tissue volume and calcified vessel volume per patent vessel volume were augmented (p<0.05) 262%, 375% and 263%, respectively, in the old vs. young rats. Ossified and patent vessel number was higher (171%) and lower (40%), respectively, in the old vs. young rats. Finally, adipocyte volume per patent vessel volume was higher (86%) with age. This study is the first to report ossification of bone marrow blood vessels in rats and humans. Ossification presumably results in "microvascular dead space" in regard to loss of patency and vasomotor function as opposed to necrosis. Progression of bone microvascular ossification may provide the common link associated with age-related changes in bone and bone marrow. The clinical implications may be evident in the

  13. Red blood cell production

    MedlinePlus

    ... hemocytoblasts give rise to all of the formed elements in blood. If a hemocytoblast commits to becoming a cell called a proerythroblast, it will develop into a new red blood cell. The formation of a red ...

  14. Hanford External Dosimetry Technical Basis Manual PNL-MA-842

    SciTech Connect

    Rathbone, Bruce A.

    2010-01-01

    The Hanford External Dosimetry Technical Basis Manual PNL-MA-842 documents the design and implementation of the external dosimetry system used at Hanford. The manual describes the dosimeter design, processing protocols, dose calculation methodology, radiation fields encountered, dosimeter response characteristics, limitations of dosimeter design under field conditions, and makes recommendations for effective use of the dosimeters in the field. The manual describes the technical basis for the dosimetry system in a manner intended to help ensure defensibility of the dose of record at Hanford and to demonstrate compliance with 10 CFR 835, DOELAP, DOE-RL, ORP, PNSO, and Hanford contractor requirements. The dosimetry system is operated by PNNL’s Hanford External Dosimetry Program (HEDP) which provides dosimetry services to all Hanford contractors. The primary users of this manual are DOE and DOE contractors at Hanford using the dosimetry services of PNNL. Development and maintenance of this manual is funded directly by DOE and DOE contractors. Its contents have been reviewed and approved by DOE and DOE contractors at Hanford through the Hanford Personnel Dosimetry Advisory Committee (HPDAC) which is chartered and chaired by DOE-RL and serves as means of coordinating dosimetry practices across contractors at Hanford. This manual was established in 1996. Since its inception, it has been revised many times and maintained by PNNL as a controlled document with controlled distribution. The first revision to be released through PNNL’s Electronic Records & Information Capture Architecture (ERICA) database was designated Revision 0. Revision numbers that are whole numbers reflect major revisions typically involving significant changes to all chapters in the document. Revision numbers that include a decimal fraction reflect minor revisions, usually restricted to selected chapters or selected pages in the document. Maintenance and distribution of controlled hard copies of the

  15. Bone marrow cells and myocardial regeneration.

    PubMed

    Wang, Fu-Sheng; Trester, Cathy

    2004-05-01

    Hematopoietic stem cell (HSC) plasticity and its clinical application have been studied profoundly in the past few years. Recent investigations indicate that HSC and other bone marrow stem cells can develop into other tissues. Because of the high morbidity and mortality of myocardial infarction and other heart disorders, myocardial regeneration is a good example of the clinical application of HSC plasticity in regenerative medicine. Preclinical studies in animals suggest that the use of this kind of treatment can reconstruct heart blood vessels, muscle, and function. Some clinical study results have been reported in the past 2 years. In 2003, reports of myocardial regeneration treatment increased significantly. Other studies include observations on the cell surface markers of transplanted cells and treatment efficacy. Some investigations, such as HSC testing, have focused on clinical applications using HSC plasticity and bone marrow transplantation to treat different types of disorders. In this review, we focus on the clinical application of bone marrow cells for myocardial regeneration.

  16. Induction of marrow hypoxia by radioprotective agents

    SciTech Connect

    Allalunis-Turner, M.J.; Walden, T.L. Jr.; Sawich, C.

    1989-06-01

    The ability of thiol and non-thiol radioprotectors to induce hypoxia was determined using the binding of (/sup 3/H)misonidazole by bone marrow cells as a measure of hypoxia. When administered at maximally radioprotective doses, four drugs (WR-2721, cysteamine, 5-hydroxytryptamine, and 16,16-dimethyl prostaglandin E2) significantly increased the amount of (/sup 3/H)misonidazole bound by marrow cells, while no significant increase in binding was observed with three other agents (endotoxin, AET, superoxide dimutase). Doses of WR-2721 previously shown to provide suboptimal radioprotection did not significantly increase /sup 3/H-misonidazole binding. These results suggest that the physiological effects of some radioprotectors, that is, their ability to induce marrow hypoxia, may contribute to their efficacy in vivo.

  17. Cell survival kinetics in peripheral blood and bone marrow during total body irradiation for marrow transplantation

    SciTech Connect

    Shank, B.; Andreeff, M.; Li, D.

    1983-11-01

    Cell survival kinetics in both peripheral blood and in bone marrow have been studied over the time course of hyperfractionated total body irradiation (TBI) for bone marrow transplantation. Our unique TBI regimen allows the study of the in vivo radiation effect uncomplicated by prior cyclophosphamide, since this agent is given after TBI in our cytoreduction scheme. Peripheral blood cell concentrations were monitored with conventional laboratory cell counts and differentials. Absolute bone marrow cell concentrations were monitored by measuring cell concentrations in an aspirate sample and correcting for dilution with blood by a cell cycle kinetic method using cytofluorometry. For lymphocytes in peripheral blood in patients in remission, the effective D/sub 0/ ranged from 373 rad in 10 children less than or equal to 10 y old, to 536 rad in the four patients between 11 to 17 y old, while n = 1.0 in all groups. There was no trend observed according to age. Granulocytes had a much higher effective D/sub 0/, approximately 1000 rad in vivo. Absolute nucleated cell concentration in marrow dropped slowly initially, due to an increased lymphocyte concentration in marrow during a concurrent drop in lymphocyte concentration in peripheral blood, but eventually fell on the last day of TBI ranging from 7 to 44% of the initial marrow nucleated cell concentration. Marrow myeloid elements, however, dropped continuously throughout the course of TBI.

  18. Bone Marrow Stress Decreases Osteogenic Progenitors.

    PubMed

    Ng, Adeline H; Baht, Gurpreet S; Alman, Benjamin A; Grynpas, Marc D

    2015-11-01

    Age-related bone loss may be a result of declining levels of stem cells in the bone marrow. Using the Col2.3Δtk (DTK) transgenic mouse, osteoblast depletion was used as a source of marrow stress in order to investigate the effects of aging on osteogenic progenitors which reside in the marrow space. Five-month-old DTK mice were treated with one or two cycles of ganciclovir to conditionally ablate differentiated osteoblasts, whereas controls were saline-treated. Treatment cycles were two weeks in length followed by four weeks of recovery. All animals were sacrificed at 8 months of age; bone marrow stromal cells (BMSCs) were harvested for cell culture and whole bones were excised for bone quality assessment. Colony-forming unit (CFU) assays were conducted to investigate the osteogenic potential of BMSC in vitro, and RNA was extracted to assess the expression of osteoblastic genes. Bone quality assessments included bone histomorphometry, TRAP staining, microcomputed tomography, and biomechanical testing. Osteoblast depletion decreased CFU-F (fibroblast), CFU-ALP (alkaline phosphatase), and CFU-VK (von Kossa) counts and BMSC osteogenic capacity in cell culture. Ex vivo, there were no differences in bone mineral density of vertebrae or femurs between treatment groups. Histology showed a decrease in bone volume and bone connectivity with repeated osteoblast depletion; however, this was accompanied by an increase in bone formation rate. There were no notable differences in osteoclast parameters or observed bone marrow adiposity. We have developed a model that uses bone marrow stress to mimic age-related decrease in osteogenic progenitors. Our data suggest that the number of healthy BMSCs and their osteogenic potential decline with repeated osteoblast depletion. However, activity of the remaining osteoblasts increases to compensate for this loss in progenitor osteogenic potential.

  19. RED-LETTER DAYS

    EPA Science Inventory

    The word "red-letter" is an adjective meaning "of special significance." It's origin is from the practice of marking Christian holy days in red letters on calendars. The "red-letter days" to which I refer occurred while I was a graduate student of ...

  20. Dosimetry quality assurance in Martin Marietta Energy Systems' centralized external dosimetry system

    SciTech Connect

    Souleyrette, M.L.

    1992-10-23

    External dosimetry needs at the four Martin Marietta Energy Systems facilities are served by Energy Systems Centralized External Dosimetry System (CEDS). The CEDS is a four plant program with four dosimeter distribution centers and two dosimeter processing centers. Each plant has its own distribution center, while processing centers are located at ORNL and the Y-12 Plant. The program has been granted accreditation by the Department of Energy Laboratory Accreditation Program (DOELAP). The CEDS is a TLD based system which is responsible for whole-body beta-gamma, neutron, and extremity monitoring. Beta-gamma monitoring is performed using the Harshaw/Solon Technologies model 8805 dosimeter. Effective October 1, 1992 the standard silver mylar has been replaced with an Avery mylar foil blackened on the underside with ink. This was done in an effort to reduce the number of light induced suspect readings. At this time we have little operational experience with the new blackened mylars-The CEDS neutron dosimeter is the Harshaw model 8806B. This card/holder configuration contains two TLD-600/TLD-700 chip pairs; one pair is located beneath a cadmium filter and one pair is located beneath a plastic filter. In routine personnel monitoring the CEDS neutron dosimeter is always paired with a CEDS beta-gamma dosimeter.The CEDS extremity dosimeter is composed of a Harshaw thin TLD-700 dosiclip placed inside a Teledyne RB-4 finger sachet. The finger sachet provides approximately 7 mg/cm[sup 2] filtration over the chip. A teflon ring surrounds the dosiclip to help prevent tearing of the vinyl sachet.

  1. Marrow-tumor interactions: the role of the bone marrow in controlling chemically induced tumors

    SciTech Connect

    Rosse, C

    1980-01-01

    This report summarizes work done to evaluate the role of the bone marrow in tumor growth regulation. Work done with the MCA tumor showed that several subclasses of mononuclear bone marrow cells (e.g. natural regulatory cell, NRC) play a major role in the regulation of tumor growth. Experiments with the spontaneous CE mammary carcinoma system illustrate that a rapid growth of certain neoplasms may be due to the fact that through some as yet undefined mechanism the tumor eliminates mononuclear cells in the bone marrow of the host and stops their production. (KRM)

  2. What Is a Blood and Marrow Stem Cell Transplant?

    MedlinePlus

    ... and Bone Marrow Transplant Also known as hematopoietic stem cell transplant, hematopoietic cell transplant, autologous transplant, or allogeneic ... or bone marrow transplant replaces abnormal blood-forming stem cells with healthy cells. When the healthy stem cells ...

  3. Review of physics, instrumentation and dosimetry of radioactive isotopes

    NASA Technical Reports Server (NTRS)

    Sinclair, W. K.

    1967-01-01

    General radioactive isotope information, stressing radioactivity, methods of measurement, and dosimetry of radioactive nuclides have been reviewed to serve as a reference for the medical profession. Instability of radionuclides, principal types of emission, and measurement of ionizing radiation are among the topics discussed.

  4. In vivo dosimetry with silicon diodes in total body irradiation

    NASA Astrophysics Data System (ADS)

    Oliveira, F. F.; Amaral, L. L.; Costa, A. M.; Netto, T. G.

    2014-02-01

    The aim of this work is the characterization and application of silicon diode detectors for in vivo dosimetry in total body irradiation (TBI) treatments. It was evaluated the diode response with temperature, dose rate, gantry angulations and field size. A maximum response variation of 2.2% was obtained for temperature dependence. The response variation for dose rate and angular was within 1.2%. For field size dependence, the detector response increased with field until reach a saturation region, where no more primary radiation beam contributes for dose. The calibration was performed in a TBI setup. Different lateral thicknesses from one patient were simulated and then the calibration factors were determined by means of maximum depth dose readings. Subsequent to calibration, in vivo dosimetry measurements were performed. The response difference between diode readings and the prescribed dose for all treatments was below 4%. This difference is in agreement as recommended by the International Commission on Radiation Units and Measurements (ICRU), which is ±5%. The present work to test the applicability of a silicon diode dosimetry system for performing in vivo dose measurements in TBI techniques presented good results. These measurements demonstrated the value of diode dosimetry as a treatment verification method and its applicability as a part of a quality assurance program in TBI treatments.

  5. Radiation dosimetry onboard the International Space Station ISS.

    PubMed

    Berger, Thomas

    2008-01-01

    Besides the effects of the microgravity environment, and the psychological and psychosocial problems encountered in confined spaces, radiation is the main health detriment for long duration human space missions. The radiation environment encountered in space differs in nature from that on earth, consisting mostly of high energetic ions from protons up to iron, resulting in radiation levels far exceeding the ones encountered on earth for occupational radiation workers. Therefore the determination and the control of the radiation load on astronauts is a moral obligation of the space faring nations. The requirements for radiation detectors in space are very different to that on earth. Limitations in mass, power consumption and the complex nature of the space radiation environment define and limit the overall construction of radiation detectors. Radiation dosimetry onboard the International Space Station (ISS) is onboard the International Space Station (ISS) is accomplished to one part as "operational" dosimetry accomplished to one part as "operational" dosimetry aiming for area monitoring of the radiation environment as well as astronaut surveillance. Another part focuses on "scientific" dosimetry aiming for a better understanding of the radiation environment and its constitutes. Various research activities for a more detailed quantification of the radiation environment as well as its distribution in and outside the space station have been accomplished in the last years onboard the ISS. The paper will focus on the current radiation detectors onboard the ISS, their results, as well as on future planned activities.

  6. Metamorphic modifications and EPR dosimetry in tooth enamel.

    PubMed

    Brik, A; Radchuk, V; Scherbina, O; Matyash, M; Gaver, O

    1996-01-01

    It is shown that metamorphic modifications in tooth enamel have an essential influence on the results of EPR dosimetry. The metamorphic modifications in minerals of biological origin proceed more quickly than in usual natural minerals. The approaches which at present are applied for reconstruction of doses connected with Chernobyl accident need additional investigation.

  7. Dosimetry for audit and clinical trials: challenges and requirements

    NASA Astrophysics Data System (ADS)

    Kron, T.; Haworth, A.; Williams, I.

    2013-06-01

    Many important dosimetry audit networks for radiotherapy have their roots in clinical trial quality assurance (QA). In both scenarios it is essential to test two issues: does the treatment plan conform with the clinical requirements and is the plan a reasonable representation of what is actually delivered to a patient throughout their course of treatment. Part of a sound quality program would be an external audit of these issues with verification of the equivalence of plan and treatment typically referred to as a dosimetry audit. The increasing complexity of radiotherapy planning and delivery makes audits challenging. While verification of absolute dose delivered at a reference point was the standard of external dosimetry audits two decades ago this is often deemed inadequate for verification of treatment approaches such as Intensity Modulated Radiation Therapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT). As such, most dosimetry audit networks have successfully introduced more complex tests of dose delivery using anthropomorphic phantoms that can be imaged, planned and treated as a patient would. The new challenge is to adapt this approach to ever more diversified radiotherapy procedures with image guided/adaptive radiotherapy, motion management and brachytherapy being the focus of current research.

  8. Bayesian internal dosimetry calculations using Markov Chain Monte Carlo.

    PubMed

    Miller, G; Martz, H F; Little, T T; Guilmette, R

    2002-01-01

    A new numerical method for solving the inverse problem of internal dosimetry is described. The new method uses Markov Chain Monte Carlo and the Metropolis algorithm. Multiple intake amounts, biokinetic types, and times of intake are determined from bioassay data by integrating over the Bayesian posterior distribution. The method appears definitive, but its application requires a large amount of computing time.

  9. Dosimetry studies on prototype 241Am sources for brachytherapy.

    PubMed

    Nath, R; Gray, L

    1987-06-01

    Sealed sources of 241Am emit primarily 60 keV photons which, because of multiple Compton scattering, produce dose distributions in water that are comparable to those from 226Ra or 137Cs. However, americium gamma rays can be shielded by thin layers of high atomic number materials since the half value layer thickness is only 1/8th of a mm of lead for americium gamma rays as compared to a value of 12 mm for 226Ra gamma rays. This may allow effective in vivo shielding of critical organs, for example; the bladder can be partially shielded by hypaque solution, and the rectum and sigmoid colon by barium sulfate. In addition, the exposure to medical personnel involved in intracavitary application and patient care may be reduced substantially by the use of relatively thin lead aprons and light weight, portable shields. To investigate the feasibility of 241Am sources for intracavitary irradiation, dosimetry studies on prototype 241Am sources have been performed and a computer model for the determination of dose distributions around encapsulated cylindrical sources of 241Am has been developed and tested. Results of dosimetry measurements using ionization chambers, lithium fluoride thermoluminescent dosimeters, a scanning scintillation probe, and film dosimetry, confirm theoretical predictions that these sources can deliver dose rates adequate for intracavitary irradiation. Further dosimetry measurements in simulated clinical situations using lead foils and test tubes filled with hypaque or barium sulfate, confirm the predicted effectiveness of in vivo shielding which can be readily achieved with 241Am sources.

  10. IMRT verification using a radiochromic/optical-CT dosimetry system

    NASA Astrophysics Data System (ADS)

    Oldham, Mark; Guo, Pengyi; Gluckman, Gary; Adamovics, John

    2006-12-01

    This work represents our first experiences relating to IMRT verification using a relatively new 3D dosimetry system consisting of a PRESAGETM dosimeter (Heuris Inc, Pharma LLC) and an optical-CT scanning system (OCTOPUSTM TM MGS Inc). This work builds in a step-wise manner on prior work in our lab.

  11. Dose calibration optimization and error propagation in polymer gel dosimetry

    NASA Astrophysics Data System (ADS)

    Jirasek, A.; Hilts, M.

    2014-02-01

    This study reports on the relative precision, relative error, and dose differences observed when using a new full-image calibration technique in NIPAM-based x-ray CT polymer gel dosimetry. The effects of calibration parameters (e.g. gradient thresholding, dose bin size, calibration fit function, and spatial remeshing) on subsequent errors in calibrated gel images are reported. It is found that gradient thresholding, dose bin size, and fit function all play a primary role in affecting errors in calibrated images. Spatial remeshing induces minimal reductions or increases in errors in calibrated images. This study also reports on a full error propagation throughout the CT gel image pre-processing and calibration procedure thus giving, for the first time, a realistic view of the errors incurred in calibrated CT polymer gel dosimetry. While the work is based on CT polymer gel dosimetry, the formalism is valid for and easily extended to MRI or optical CT dosimetry protocols. Hence, the procedures developed within the work are generally applicable to calibration of polymer gel dosimeters.

  12. BUILDING 122 CONTAINS THREE GENERAL AREAS: OFFICE AREAS, INTERNAL DOSIMETRY, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BUILDING 122 CONTAINS THREE GENERAL AREAS: OFFICE AREAS, INTERNAL DOSIMETRY, AND MEDICAL/HEALTH. BUILDING 122 SHARES A COMMON WALL WITH BUILDING 121, THE PLANT SECURITY BUILDING. THE TWO-STORY BUILDING IN THE BACKGROUND IS BUILDING 111. (9/26/52) - Rocky Flats Plant, Emergency Medical Services Facility, Southwest corner of Central & Third Avenues, Golden, Jefferson County, CO

  13. Bioelectromagnetics, Carl Durney, and dosimetry: some historical remarks.

    PubMed

    Schwan, H P

    1999-01-01

    The contributions of Carl Durney to dosimetry have decisively advanced the bioelectromagnetics field and led to significant revisions of relevant health standards. Three items come to mind while studying his work: 1. The work of Carl Durney and his colleagues in dosimetry has advanced the bioelectromagnetics field most significantly whereas more abundant work of a biomedical nature has had less impact. More biophysics work is desirable. 2. The rationale for the specific absorption rate as a basis of health standards needs further elaboration. The need for scaling animal results is stressed. 3. Dosimetry at the cellular level (microdosimetry) is essential if one cares to discuss direct field interactions at the cellular and macromolecular level. Carl Durney's recognition of this need is stated. Carl Durney's wide range of productive interests is indicated by several tables. They summarize his many contributions to electrical engineering, education, bioelectromagnetic dosimetry, hyperthermia, NMR, and field-induced biophysical phenomena at the molecular and cellular level. His scientific work is summarized, including how his interest changed with time. His scientific accomplishment and productive interaction with students, colleagues, and society sets an example to be admired.

  14. T2-based temperature monitoring in trabecular bone marrow for MRgHIFU

    NASA Astrophysics Data System (ADS)

    Ozhinsky, Eugene; Han, Misung; Krug, Roland; Rieke, Viola

    2017-03-01

    Current clinical protocols for HIFU treatment of painful bone metastases rely on measurement of temperature change of adjacent muscle to estimate the temperature of the bone. In this study, we investigated if T2-based temperature mapping could be used to determine the temperature within ex vivo trabecular bone during HIFU ablation. We have shown that T2-based ablation monitoring in the red marrow in trabecular bone is feasible. The linear relationship between T2 change and temperature could be used to quantify the temperature during heating of up to 60°C.

  15. Patient-Specific Dosimetry of Pretargeted Radioimmunotherapy Using CC49 Fusion Protein in Patients with Gastrointestinal Malignancies.

    SciTech Connect

    Shen, Shang; Forero, Andres; LoBuglio, Albert F.; Breitz, H; Khazaeli, M B.; Fisher, Darrell R.; Wang, W Q.; Meredith, Ruby F.

    2005-04-01

    Patient-Specific Dosimetry of Pretargeted Radioimmunotherapy Using CC49 Fusion Protein in Patients with Gastrointestinal Malignancies. Shen S, Forero A, Lobuglio AF, Breitz H, Khazaeli MB, Fisher DR, Wang W, Meredith RF. Department of Radiation Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, Alabama, and Radioisotopes Program at Pacific Northwest National Laboratory, Richland, Washington. Pretargeted radioimmunotherapy (RIT) using CC49 fusion protein, comprised of CC49-(scFv)(4) and streptavidin, in conjunction with (90)Y/(111)In-DOTA-biotin (DOTA = dodecanetetraacetic acid) provides a new opportunity to improve efficacy by increasing the tumor-to-normal tissue dose ratio. To our knowledge, the patient-specific dosimetry of pretargeted (90)Y/(111)In-DOTA-biotin after CC49 fusion protein in patients has not been reported previously. METHODS: Nine patients received 3-step pretargeted RIT: (a) 160 mg/m(2) of CC49 fusion protein, (b) synthetic clearing agent (sCA) at 48 or 72 h later, and (c) (90)Y/(111)In-DOTA-biotin 24 h after the sCA administration. Sequential whole-body (111)In images were acquired immediately and at 2-144 h after injection of (90)Y/(111)In-DOTA-biotin. Geometric-mean quantification with background and attenuation correction was used for liver and lung dosimetry. Effective point source quantification was used for spleen, kidneys, and tumors. Organ and tumor (90)Y doses were calculated based on (111)In imaging data and the MIRD formalism using patient-specific organ masses determined from CT images. Patient-specific marrow doses were determined based on radioactivity concentration in the blood. RESULTS: The (90)Y/(111)In-DOTA-biotin had a rapid plasma clearance, which was biphasic with <10% residual at 8 h. Organ masses ranged from 1,263 to 3,855 g for liver, 95 to 1,009 g for spleen, and 309 to 578 g for kidneys. The patient-specific mean (90)Y dose (cGy/37 MBq, or rad/mCi) was 0.53 (0.32-0.78) to whole body

  16. EANM Dosimetry Committee series on standard operational procedures for pre-therapeutic dosimetry II. Dosimetry prior to radioiodine therapy of benign thyroid diseases.

    PubMed

    Hänscheid, Heribert; Canzi, Cristina; Eschner, Wolfgang; Flux, Glenn; Luster, Markus; Strigari, Lidia; Lassmann, Michael

    2013-07-01

    The EANM Dosimetry Committee Series "Standard Operational Procedures for Pre-Therapeutic Dosimetry" (SOP) provides advice to scientists and clinicians on how to perform patient-specific absorbed dose assessments. This particular SOP describes how to tailor the therapeutic activity to be administered for radioiodine therapy of benign thyroid diseases such as Graves' disease or hyperthyroidism. Pretherapeutic dosimetry is based on the assessment of the individual (131)I kinetics in the target tissue after the administration of a tracer activity. The present SOP makes proposals on the equipment to be used and guides the user through the measurements. Time schedules for the measurement of the fractional (131)I uptake in the diseased tissue are recommended and it is shown how to calculate from these datasets the therapeutic activity necessary to administer a predefined target dose in the subsequent therapy. Potential sources of error are pointed out and the inherent uncertainties of the procedures depending on the number of measurements are discussed. The theoretical background and the derivation of the listed equations from compartment models of the iodine kinetics are explained in a supplementary file published online only.

  17. The biodistribution and dosimetry of {sup 117m}Sn DTPA with special emphasis on active marrow absorbed doses

    SciTech Connect

    Stubbs, J.; Atkins, H.

    1999-01-01

    {sup 117m}Sn(4+) DTPA is a new radiopharmaceutical for the palliation of pain associated with metastatic bone cancer. Recently, the Phase 2 clinical trials involving 47 patients were completed. These patients received administered activities in the range 6.7--10.6 MBq/kg of body mass. Frequent collections of urine were acquired over the first several hours postadministration and daily cumulative collections were obtained for the next 4--10 days. Anterior/posterior gamma camera images were obtained frequently over the initial 10 days. Radiation dose estimates were calculated for 8 of these patients. Each patient`s biodistribution data were mathematically simulated using a multicompartmental model. The model consisted of the following compartments: central, bone, kidney, other tissues, and cumulative urine. The measured cumulative urine data were used as references for the cumulative urine excretion compartment. The total-body compartment (sum of the bone surfaces, central, kidney, and other tissues compartments) was reference to all activity not excreted in the urine.

  18. Development of probabilistic internal dosimetry computer code

    NASA Astrophysics Data System (ADS)

    Noh, Siwan; Kwon, Tae-Eun; Lee, Jai-Ki

    2017-02-01

    Internal radiation dose assessment involves biokinetic models, the corresponding parameters, measured data, and many assumptions. Every component considered in the internal dose assessment has its own uncertainty, which is propagated in the intake activity and internal dose estimates. For research or scientific purposes, and for retrospective dose reconstruction for accident scenarios occurring in workplaces having a large quantity of unsealed radionuclides, such as nuclear power plants, nuclear fuel cycle facilities, and facilities in which nuclear medicine is practiced, a quantitative uncertainty assessment of the internal dose is often required. However, no calculation tools or computer codes that incorporate all the relevant processes and their corresponding uncertainties, i.e., from the measured data to the committed dose, are available. Thus, the objective of the present study is to develop an integrated probabilistic internal-dose-assessment computer code. First, the uncertainty components in internal dosimetry are identified, and quantitative uncertainty data are collected. Then, an uncertainty database is established for each component. In order to propagate these uncertainties in an internal dose assessment, a probabilistic internal-dose-assessment system that employs the Bayesian and Monte Carlo methods. Based on the developed system, we developed a probabilistic internal-dose-assessment code by using MATLAB so as to estimate the dose distributions from the measured data with uncertainty. Using the developed code, we calculated the internal dose distribution and statistical values ( e.g. the 2.5th, 5th, median, 95th, and 97.5th percentiles) for three sample scenarios. On the basis of the distributions, we performed a sensitivity analysis to determine the influence of each component on the resulting dose in order to identify the major component of the uncertainty in a bioassay. The results of this study can be applied to various situations. In cases of

  19. Fiber-coupled Luminescence Dosimetry in Therapeutic and Diagnostic Radiology

    NASA Astrophysics Data System (ADS)

    Andersen, Claus E.

    2011-05-01

    Fiber-coupled luminescence dosimetry is an emerging technology with several potentially attractive features of relevance for uses in therapeutic and diagnostic radiology: direct water equivalence (i.e. no significant perturbation of the radiation field in a water phantom or a patient), sub-mm detector size, high dynamic range (below a mGy to several Gy), microsecond time resolution, and absence of electrical wires or other electronics in the dosimeter probe head. Fiber-coupled luminescence dosimetry systems typically consist of one or more small samples of phosphor, e.g. a mg of plastic scintillator, attached to 10-20 m long optical fiber cables of plastic. During irradiation, each dosimeter probe spontaneously emits radioluminescence (RL) in proportion to the dose rate. The luminescence intensity can be detected with photomultiplier tubes, CCD cameras or other highly sensitive photodetectors. Some crystalline phosphors, such as carbon-doped aluminium oxide (Al2O3:C) have the ability to store charge produced in the crystal during irradiation. The stored charge may later be released by fiber-guided laser light under emission of so-called optically stimulated luminescence (OSL). The OSL signal therefore reflects the passively integrated dose. In contrast to thermoluminescence dosimetry, fiber-coupled OSL dosimetry may be performed in vivo while the dosimeter is still in the patient. Within the last few years, several improvements and new applications of these techniques have been published, and the objective of this review is to provide an introduction to this field and to outline some of these new results. Emphasis will be given to applications in medical dosimetry such as in vivo real-time dose verification in brachytherapy and methods aimed for improved quality assurance of linear accelerators.

  20. Fiber-coupled Luminescence Dosimetry in Therapeutic and Diagnostic Radiology

    SciTech Connect

    Andersen, Claus E.

    2011-05-05

    Fiber-coupled luminescence dosimetry is an emerging technology with several potentially attractive features of relevance for uses in therapeutic and diagnostic radiology: direct water equivalence (i.e. no significant perturbation of the radiation field in a water phantom or a patient), sub-mm detector size, high dynamic range (below a mGy to several Gy), microsecond time resolution, and absence of electrical wires or other electronics in the dosimeter probe head. Fiber-coupled luminescence dosimetry systems typically consist of one or more small samples of phosphor, e.g. a mg of plastic scintillator, attached to 10-20 m long optical fiber cables of plastic. During irradiation, each dosimeter probe spontaneously emits radioluminescence (RL) in proportion to the dose rate. The luminescence intensity can be detected with photomultiplier tubes, CCD cameras or other highly sensitive photodetectors. Some crystalline phosphors, such as carbon-doped aluminium oxide (Al{sub 2}O{sub 3}:C) have the ability to store charge produced in the crystal during irradiation. The stored charge may later be released by fiber-guided laser light under emission of so-called optically stimulated luminescence (OSL). The OSL signal therefore reflects the passively integrated dose. In contrast to thermoluminescence dosimetry, fiber-coupled OSL dosimetry may be performed in vivo while the dosimeter is still in the patient. Within the last few years, several improvements and new applications of these techniques have been published, and the objective of this review is to provide an introduction to this field and to outline some of these new results. Emphasis will be given to applications in medical dosimetry such as in vivo real-time dose verification in brachytherapy and methods aimed for improved quality assurance of linear accelerators.

  1. The diagnostic value of bone marrow iron.

    PubMed

    Wulfhekel, U; Düllmann, J

    1990-01-01

    The light and electronmicroscopic representation of non-haemiron in the bone-marrow provides the unique opportunity of extensively evaluating the iron metabolism. In the bone-marrow, macrophages represent the physiological place of iron storage. The iron in the cytoplasma is stored in them in the form of free ferritin molecules and lysomally as aggregated ferritin and/or haemosiderin in siderosomes. In an equal iron balance and unimpaired internal iron exchange only erythroblasts (sideroblasts) and erythrocytes (siderocytes) of the bone-marrow besides macrophages possess siderosomes. In addition to this physiological or orthotopic iron storage a heterotopic iron storage can be observed under pathological conditions, particularly with iron overloading of the organism, in the endothelial cells of sinusoids and plasma cells. In detail, the patterns of iron storage in the bone-marrow are described in the different stages of iron deficiency, disturbance of iron utilization in chronically inflammatory processes or tumour diseases, condition after intravenous iron administration, transfusion siderosis, hereditary haemochromatosis and sideroblastic anaemia.

  2. HLA Typing for Bone Marrow Transplantation

    DTIC Science & Technology

    2007-10-31

    storage of the first product at the apheresis center. It is also common, particularly if products arrive late in the business day, for either PBSC or marrow...over time with products stored at 20°C whereas no notable change was observed with products stored at 4’C (p ɘ.0003). However for BM, platelet

  3. Post-5-fluorouracil human marrow: stem cell characteristics and renewal properties after autologous marrow transplantation.

    PubMed

    Stewart, F M; Temeles, D; Lowry, P; Thraves, T; Grosh, W W; Quesenberry, P J

    1993-05-01

    The effect of 5-fluorouracil (5-FU) pretreatment on human bone marrow (BM) progenitor/stem cells and recovery of hematopoiesis after autologous marrow transplant was studied. Twenty-one patients were treated with 5-FU (15 mg/kg to 45 mg/kg) intravenously (IV) for 1 to 3 days administered 6 to 22 days before BM harvest. Post-FU marrow was infused into 15 patients after high-dose cyclophosphamide, carmustine (BCNU), and VP-16 (CBV). Seventeen patients (historical controls) were treated with CBV and autologous BM transplantation but did not receive 5-FU before marrow harvest. The groups were comparable for diagnosis and prior therapy. In the 5-FU-treated group and control group, median recovery times for platelet count to 50,000/mm3 were 20 and 30 days, respectively (P = .007), and for platelet count to 100,000/mm3, 23 and 38 days, respectively (P = .007), while neutrophil recovery was not significantly altered. In vitro cultures with 1 to 7 growth factors (interleukin-1 [IL-1], IL-3, IL-4, IL-6, colony-stimulating factor-1 [CSF-1], granulocyte-macrophage colony-stimulating factor [GM-CSF], and G-CSF) were performed. In 8 of 10 patients whose marrow was studied before and after 5-FU treatment, the numbers of CFU-C responsive to the combination of GM-CSF and IL-3 was increased 6.15-fold by 5-FU pretreatment. In 4 of these patients, thymidine suicide of GM-CSF- and IL-3-stimulated CFU-C ranged from 17% to 42%. High proliferative potential colony-forming cell (HPP-CFC) was observed in low frequency in normal marrow and patient's marrow before 5-FU treatment. In 11 of 16 patients pretreated with 5-FU, increased numbers of HPP-CFC were noted. GM-CSF and IL-3 interacted synergistically to stimulate HPP-CFC. Multifactor combinations, especially GM-CSF + G-CSF + IL-3 + IL-6 + IL-1 + CSF-1 did not increase total colony count or classic HPP-CFC but did result in altered morphology, producing huge, loose colonies. The marrow from patients pretreated with 5-FU is enriched with

  4. GENII: The Hanford Environmental Radiation Dosimetry Software System: Volume 2, Users' manual: Hanford Environmental Dosimetry Upgrade Project

    SciTech Connect

    Napier, B.A.; Peloquin, R.A.; Strenge, D.L.; Ramsdell, J.V.

    1988-11-01

    The Hanford Environmental Dosimetry Upgrade Project was undertaken to incorporate the internal dosimetry models recommended by the International Commission on Radiological Protection (ICRP) in updated versions of the environmental pathway analysis models used at Hanford. The resulting second generation of Hanford environmental dosimetry computer codes is compiled in the Hanford Environmental Dosimetry System (Generation II, or GENII). The purpose of this coupled system of computer codes is to analyze environmental contamination of, air, water, or soil. This is accomplished by calculating radiation doses to individuals or populations. GENII is described in three volumes of documentation. This second volume is a Users' Manual, providing code structure, users' instructions, required system configurations, and QA-related topics. The first volume describes the theoretical considerations of the system. The third volume is a Code Maintenance Manual for the user who requires knowledge of code detail. It includes logic diagrams, global dictionary, worksheets, example hand calculations, and listings of the code and its associated data libraries. 27 refs., 17 figs., 23 tabs.

  5. GENII (Generation II): The Hanford Environmental Radiation Dosimetry Software System: Volume 3, Code maintenance manual: Hanford Environmental Dosimetry Upgrade Project

    SciTech Connect

    Napier, B.A.; Peloquin, R.A.; Strenge, D.L.; Ramsdell, J.V.

    1988-09-01

    The Hanford Environmental Dosimetry Upgrade Project was undertaken to incorporate the internal dosimetry models recommended by the International Commission on Radiological Protection (ICRP) in updated versions of the environmental pathway analysis models used at Hanford. The resulting second generation of Hanford environmental dosimetry computer codes is compiled in the Hanford Environmental Dosimetry System (Generation II, or GENII). This coupled system of computer codes is intended for analysis of environmental contamination resulting from acute or chronic releases to, or initial contamination of, air, water, or soil, on through the calculation of radiation doses to individuals or populations. GENII is described in three volumes of documentation. This volume is a Code Maintenance Manual for the serious user, including code logic diagrams, global dictionary, worksheets to assist with hand calculations, and listings of the code and its associated data libraries. The first volume describes the theoretical considerations of the system. The second volume is a Users' Manual, providing code structure, users' instructions, required system configurations, and QA-related topics. 7 figs., 5 tabs.

  6. A study of four radiochromic films currently used for (2D) radiation dosimetry

    NASA Astrophysics Data System (ADS)

    Yao, Tiantian; Luthjens, Leonard H.; Gasparini, Alessia; Warman, John M.

    2017-04-01

    We have measured the dose, D, and dose rate, D', dependences of the radiation-induced change in optical absorption of four radiochromic films currently used for (2D) dosimetry: GafChromic® types EBT3, MD-V3, HD-V2 and HD-810. We have irradiated the films using two 60Co γ-ray sources with dose rates of 2 and 30 Gy/min and a 200 kVp X-ray source with dose rates from 0.2 to 1.0 Gy/min. The 48-bit RGB image files of the films, obtained using an Epson V700 flatbed scanner, were color-channel separated and the red, green and blue pixel levels, P(D), were determined using ImageJ software. The relationship P(D)/P(0)=[1+hD/m]/[1+D/m] is found to provide a good description of the dose dependence for all four films at all dose rates. The parameter h is the "plateau level" of P(D)/P(0) approached at high doses, i.e. P(∞)/P(0). The parameter m is the "median-dose" for which P(D)/P(0)(1+h)/2 which is the half point in the dynamic range of the particular film. The best-fit values of m over the dose rate range from 0.2 to 25 Gy/min using the red pixels were 1.42±0.03, 11.1±0.4, 63.6±0.9 and 60.6±1.6 Gy for EBT3, MD-V3, HD-V2 and HD-810 respectively. Using the green pixels the median dose is 1.8 times larger for the first 3 films and 2.5 times larger for HD-810. The blue pixels are considered unsuitable for dosimetry because of the large value of h (>0.4) and the resulting small dynamic range.

  7. SU-E-T-475: Improvements to Total Body Irradiation Dosimetry Efficiency with EBT3 Radiochromic Film and a Template System

    SciTech Connect

    Butson, M; Pope, D; Whitaker, M

    2015-06-15

    Purpose: Total Body Irradiation (TBI) treatments are mainly used in a preparative regimen for haematopoietic stem cell (or bone marrow) transplantation. Our standard regimen is a 12 Gy / 6 fraction bi-daily technique. To evaluate the delivered dose homogeneity to the patient, EBT3 Gafchromic film is positioned at the head, neck, chest, pelvis and groin for all fractions. A system has been developed to simply and accurately prepare and readout the films for patient dose assessment. Methods: A process involving easy preparation and analysis has been produced to minimise the time requirements for TBI dosimetry. One sheet of EBT3 film is used to prepare treatment dosimeters for all fractions, including calibration films, and an automated dose analysis system for easy evaluation and calculation of estimated in-vivo doses was developed. A desktop scanner is used with a dedicated TBI film template to accurately position the films for Image J analysis and extraction. Dental wax bolus and zip-lock bag holders are used to hold the EBT3 film in place during irradiation. Results: To adequately provide dosimetry information for a 6 fraction, TBI patient, only one sheet of Gafchromic EBT3 film is required. The dosimeters are cut, using a template, into 19 mm squares which are then placed between two 30 mm x 30 mm x 4.5 mm wax blocks for bolus. All packages are prepared before the first treatment fraction. The scanning and analysis process can be completed in less than 10 minutes after a 240 min development period. Results have shown that a high level of accuracy and reproducibility can be achieved using the template system provided. Conclusion: Gafchromic EBT3 film provides an adequate in-vivo dosimetry measure for TBI patients. Using a template based system on a dedicated desktop scanner, in-vivo results can be ascertained quickly and accurately.

  8. Performance of the CEDS Accident Dosimetry System at the 1995 Los Alamos National Laboratory Nuclear Accident Dosimetry Intercomparison

    SciTech Connect

    McMahan, K.L.; Schwanke, L.J.

    1996-12-01

    In July 1995, LANL hosted an accident dosimetry intercomparison. When all reactors on the Oak Ridge Reservation were idled in 1988, the Health Physics Research Reactor (HPRR), which had been used for 22 previous intercomparisons dating from 1965, was shut down for an indefinite period. The LANL group began characterization of two critical assemblies for dosimetry purposes. As a result, NAD-23 was conceived and 10 DOE facilities accepted invitations to participate in the intercomparison. This report is a summary of the performance of one of the participants, the Centralized External Dosimetry System (CEDS). The CEDS is a cooperative personnel dosimetry arrangement between three DOE sites in Oak Ridge, Tennessee. Many successes and failures are reported herein. Generally, the TL dosimeters performed poorly and always over-reported the delivered dose. The TLD processing procedures contain efforts that would lead to large biases in the reported absorbed dose, and omit several key steps in the TLD reading process. The supralinear behavior of lithium fluoride (LiF) has not been characterized for this particular dosimeter and application (i.e., in high-dose mixed neutron/gamma fields). The use of TLD materials may also be precluded given the limitations of the LiF material itself, the TLD reading system, and the upper dose level to which accident dosimetry systems are required to perform as set forth in DOE regulations. The indium foil results confirm the expected inability of that material to predict the magnitude of the wearer`s dose reliably, although it is quite suitable as a quick-sort material. Biological sample (hair) results were above the minimum detectable activity (MDA) for only one of the tests. Several questions as to the best methods for sample handling and processing remain.

  9. Correcting lateral response artifacts from flatbed scanners for radiochromic film dosimetry

    SciTech Connect

    Lewis, David; Chan, Maria F.

    2015-01-15

    Purpose: A known factor affecting the accuracy of radiochromic film dosimetry is the lateral response artifact (LRA) induced by nonuniform response of a flatbed scanner in the direction perpendicular to the scan direction. This work reports a practical solution to eliminate such artifacts for all forms of dose QA. Methods: EBT3 films from a single production lot (02181401) cut into rectangular 4 × 5 cm{sup 2} pieces, with the long dimension parallel to the long dimension of the original 20.3 × 25.4 cm{sup 2} sheets, were exposed at a depth of 5 cm on a Varian Trilogy at the center of a 20 × 20 cm{sup 2} open field at seven doses between 50 and 1600 cGy using 6 MV photons. These films together with an unexposed film from the same production lot were lined one next to the other on an Epson 10000XL or 11000XL scanner in portrait orientation with their long dimension parallel to the scan direction. Scanned images were then obtained with the line of films positioned at seven discrete lateral locations perpendicular to the scan direction. The process was repeated in landscape orientation and on three other Epson scanners. Data were also collected for three additional production lots of EBT3 film (11051302, 03031401, and 03171403). From measurements at the various lateral positions, the scanner response was determined as a function of the lateral position of the scanned film. For a given color channel X, the response at any lateral position L is related to the response at the center, C, of the scanner by Response(C, D, X) = A{sub L,X} + B{sub L,X}⋅Response(L, D, X), where D is dose and the coefficients A{sub L,X} and B{sub L,X} are determined from the film measurements at the center of the scanner and six other discrete lateral positions. The values at intermediate lateral positions were obtained by linear interpolation. The coefficients were determined for the red, green, and blue color channels, preserving the ability to apply triple-channel dosimetry once

  10. Correcting lateral response artifacts from flatbed scanners for radiochromic film dosimetry

    PubMed Central

    Lewis, David; Chan, Maria F.

    2015-01-01

    Purpose: A known factor affecting the accuracy of radiochromic film dosimetry is the lateral response artifact (LRA) induced by nonuniform response of a flatbed scanner in the direction perpendicular to the scan direction. This work reports a practical solution to eliminate such artifacts for all forms of dose QA. Methods: EBT3 films from a single production lot (02181401) cut into rectangular 4 × 5 cm2 pieces, with the long dimension parallel to the long dimension of the original 20.3 × 25.4 cm2 sheets, were exposed at a depth of 5 cm on a Varian Trilogy at the center of a 20 × 20 cm2 open field at seven doses between 50 and 1600 cGy using 6 MV photons. These films together with an unexposed film from the same production lot were lined one next to the other on an Epson 10000XL or 11000XL scanner in portrait orientation with their long dimension parallel to the scan direction. Scanned images were then obtained with the line of films positioned at seven discrete lateral locations perpendicular to the scan direction. The process was repeated in landscape orientation and on three other Epson scanners. Data were also collected for three additional production lots of EBT3 film (11051302, 03031401, and 03171403). From measurements at the various lateral positions, the scanner response was determined as a function of the lateral position of the scanned film. For a given color channel X, the response at any lateral position L is related to the response at the center, C, of the scanner by Response(C, D, X) = AL,X + BL,X⋅Response(L, D, X), where D is dose and the coefficients AL,X and BL,X are determined from the film measurements at the center of the scanner and six other discrete lateral positions. The values at intermediate lateral positions were obtained by linear interpolation. The coefficients were determined for the red, green, and blue color channels, preserving the ability to apply triple-channel dosimetry once corrections were applied to compensate for the

  11. Radiation dosimetry of iodine-123 HEAT, an alpha-1 receptor imaging agent

    SciTech Connect

    Thomas, K.D.; Greer, D.M.; Couch, M.W.; Williams, C.M.

    1987-11-01

    Biologic distribution data in the rat were obtained for the alpha-1 adrenoceptor imaging agent (+/-) 2-(beta-(iodo-4-hydroxyphenyl)ethylaminomethyl)tetralone (HEAT) labeled with (/sup 123/I). The major excretory routes were through the liver (67%) and the kidney (33%). Internal radiation absorbed dose estimates to nine source organs, total body, the GI tract, gonads, and red bone marrow were calculated for the human using the physical decay data for (/sup 123/I). The critical organ was found to be the lower large intestine, receiving 1.1 rad per mCi of (/sup 123/I)HEAT administered. The total-body dose was found to be 58 mrad per mCi.

  12. Image analysis of nucleated red blood cells.

    PubMed

    Zajicek, G; Shohat, M; Melnik, Y; Yeger, A

    1983-08-01

    Bone marrow smears stained with Giemsa were scanned with a video camera under computer control. Forty-two cells representing the six differentiation classes of the red bone marrow were sampled. Each cell was digitized into 70 X 70 pixels, each pixel representing a square area of 0.4 micron2 in the original image. The pixel gray values ranged between 0 and 255. Zero stood for white, 255 represented black, while the numbers in between stood for the various shades of gray. After separation and smoothing the images were processed with a Sobel operator outlining the points of steepest gray level change in the cell. These points constitute a closed curve denominated as inner cell boundary, separating the cell into an inner and an outer region. Two types of features were extracted from each cell: form features, e.g., area and length, and gray level features. Twenty-two features were tested for their discriminative merit. After selecting 16, the discriminant analysis program classified correctly all 42 cells into the 6 classes.

  13. SU-E-T-275: Dose Build Up and Bolusing Characteristics for Total Body Irradiation Dosimetry

    SciTech Connect

    Butson, M; Pope, D; Whitaker, M

    2015-06-15

    Purpose: Total Body Irradiation (TBI) treatments are mainly used in a preparative regimen for haematopoietic stem cell (or bone marrow) transplantation. Our standard regimen is a 12 Gy / 6 fraction bi-daily technique. To evaluate the delivered dose homogeneity to the patient, EBT3 Gafchromic film is positioned at the head, neck, chest, pelvis and groin for all fractions. This work investigates and quantifies the build-up dose characteristics at TBI distances and requirements for in-vivo dosimetry bolusing. Methods: Percentage dose build up characteristics of photon beams have been investigated at large extended SSD’s using parallel plate ionisations chambers (Attix) and EBT3 Gafchromic film. Measurements were made to open fields at different field sizes as well as large 40cm × 40cm fields with differing scatter conditions such as the introduction of standard Perspex scattering plates at different distances to the measurement point. Results: Percentage surface dose measured values for open fields at 300 cm SSD were found to range from 20 % up to 65.5 % for fields of 5 cm × 5 cm to 40 cm × 40 cm. With the introduction of 1cm Perspex scattering plates used in TBI treatments the surface dose values increased up to 83% to 90%, depending on the position of the Perspex scattering plate compared to the measurement point. Our work showed that at least 3mm water equivalent bolus / scatter material should be placed over the EBT3 for accurate dose assessment for TBI treatments. Conclusion: Build up dose characteristics exist at long (300cm) SSD’s including treatments using Perspex scattering plates placed at various distances form the patient during TBI treatment. Top accurately assess the applied dose during treatment, in-vivo dosimeters such as Gafchromic EBT3 should have at least 3mm bolus / scatter material placed over them to measure actual applied doses.

  14. Human Cord Blood and Bone Marrow CD34+ Cells Generate Macrophages That Support Erythroid Islands

    PubMed Central

    Belay, Eyayu; Hayes, Brian J.; Blau, C. Anthony; Torok-Storb, Beverly

    2017-01-01

    Recently, we developed a small molecule responsive hyperactive Mpl-based Cell Growth Switch (CGS) that drives erythropoiesis associated with macrophages in the absence of exogenous cytokines. Here, we compare the physical, cellular and molecular interaction between the macrophages and erythroid cells in CGS expanded CD34+ cells harvested from cord blood, marrow or G-CSF-mobilized peripheral blood. Results indicated that macrophage based erythroid islands could be generated from cord blood and marrow CD34+ cells but not from G-CSF-mobilized CD34+ cells. Additional studies suggest that the deficiency resides with the G-CSF-mobilized CD34+ derived monocytes. Gene expression and proteomics studies of the in vitro generated erythroid islands detected the expression of erythroblast macrophage protein (EMP), intercellular adhesion molecule 4 (ICAM-4), CD163 and DNASE2. 78% of the erythroblasts in contact with macrophages reached the pre reticulocyte orthochromatic stage of differentiation within 14 days of culture. The addition of conditioned medium from cultures of CD146+ marrow fibroblasts resulted in a 700-fold increase in total cell number and a 90-fold increase in erythroid cell number. This novel CD34+ cell derived erythroid island may serve as a platform to explore the molecular basis of red cell maturation and production under normal, stress and pathological conditions. PMID:28135323

  15. Facilitation of allogeneic bone marrow transplantation by a T cell-specific immunotoxin containing daunomycin

    SciTech Connect

    Xie, S.S.; Inazawa, M.; Sinha, N.; Sawada, S.; Vergidis, R.; Diener, E.

    1987-12-01

    Daunomycin coupled via an acid-sensitive spacer to monoclonal Thy-1.2-specific antibody was used to purge T lymphocytes from a 1:1 mixture of murine C57BL/6J bone marrow and spleen cells prior to engraftment in fully allogeneic, irradiated BALB/c recipients. Treatment of bone marrow with the immunotoxin at a concentration used for purging had no effect on the viability of committed hematopoietic progenitor or multipotent stem cells. All of the recipients of purged bone marrow were at least 80% chimeric for donor peripheral blood cells and none developed graft-versus-host disease. Out of 50 chimeras, 49 were still alive more than 200 days posttransplantation. The chimeras were shown to be tolerant to donor tissue as tested by mixed lymphocyte reactivity, cell-mediated cytotoxicity, and skin grafting. The same tests revealed full immunocompetence of chimeras to third-party alloantigens. In vivo IgM and IgG antibody responses to sheep red blood cells were similar in magnitude in allogeneically and syngeneically reconstituted mice.

  16. Frequency of Micronucleated Erythrocytes in Rat Bone Marrow Exposed to 2.45 GHz Radiation

    NASA Astrophysics Data System (ADS)

    Trosic, I.; Busljeta, I.

    2005-01-01

    Wistar rats were exposed to 2.45 GHz continuous, radiofrequency microwave (RF/MW) field 2 hours daily, 7 days weekly, at power density 5 10 mW/cm2. Four subgroups were created in order to be irradiated 4, 16, 30 and 60 hours. Sham-exposed controls were included in the study. Animals were euthanized on the final irradiation day of each treated subgroup. Bone marrow smears were examined to determine the extent of genotoxicity after the particular treatment time. Mann-Whitney test was used for statistical evaluation of data. In comparison to the sham-exposed subgroups, the findings of polychromatic erythrocytes revealed significant differences for the 8th and 15th experimental day. Bone marrow erythrocyte maturation and/or proliferation initiated by subthermogenic RF/MW irradiation showed temporary disturbance. Thereafter, the frequency of micronucleated bone marrow red cells was significantly increased after 15 irradiation treatments. Comparison of micronucleus frequency data obtained after 2, 8 and 30 irradiation treatments did not reveal statistically significant differences between sham and treated subgroups. Under the applied experimental conditions, RF/MW irradiation initiates transitory cytogenetic effect manifested with micronucleus formation in erythropoietic cells.

  17. MR imaging of therapy-induced changes of bone marrow

    PubMed Central

    Henning, Tobias; Link, Thomas M.

    2006-01-01

    MR imaging of bone marrow infiltration by hematologic malignancies provides non-invasive assays of bone marrow cellularity and vascularity to supplement the information provided by bone marrow biopsies. This article will review the MR imaging findings of bone marrow infiltration by hematologic malignancies with special focus on treatment effects. MR imaging findings of the bone marrow after radiation therapy and chemotherapy will be described. In addition, changes in bone marrow microcirculation and metabolism after anti-angiogenesis treatment will be reviewed. Finally, new specific imaging techniques for the depiction of regulatory events that control blood vessel growth and cell proliferation will be discussed. Future developments are directed to yield comprehensive information about bone marrow structure, function and microenvironment. PMID:17021706

  18. Pure red cell aplasia following autoimmune hemolytic anemia: an enigma.

    PubMed

    Saha, M; Ray, S; Kundu, S; Chakrabarti, P

    2013-01-01

    A 26-year-old previously healthy female presented with a 6-month history of anemia. The laboratory findings revealed hemolytic anemia and direct antiglobulin test was positive. With a diagnosis of autoimmune hemolytic anemia (AIHA), prednisolone was started but was ineffective after 1 month of therapy. A bone marrow trephine biopsy revealed pure red cell aplasia (PRCA) showing severe erythroid hypoplasia. The case was considered PRCA following AIHA. This combination without clear underlying disease is rare. Human parvovirus B19 infection was not detected in the marrow aspirate during reticulocytopenia. The patient received azathioprine, and PRCA improved but significant hemolysis was once again documented with a high reticulocyte count. The short time interval between AIHA and PRCA phase suggested an increased possibility of the evolution of a single disease.

  19. EPR/PTFE dosimetry for test reactor environments

    SciTech Connect

    Vehar, D.W.; Griffin, P.J.; Quirk, T.J.

    2011-07-01

    The use of Electron Paramagnetic Resonance (EPR) spectroscopy with materials such as alanine is well established as a technique for measurement of ionizing radiation absorbed dose in photon and electron fields such as Co-60, high-energy bremsstrahlung and electron-beam fields [1]. In fact, EPR/Alanine dosimetry has become a routine transfer standard for national standards bodies such as NIST and NPL. In 1992 the Radiation Metrology Laboratory (RML) at Sandia National Laboratories implemented EPR/Alanine capabilities for use in routine and calibration activities at its Co-60 and pulsed-power facilities. At that time it also investigated the usefulness of the system for measurement of absorbed dose in the mixed neutron/photon environments of reactors such as the Sandia Pulsed Reactor and the Annular Core Research Reactor used for hardness testing of electronics. The RML concluded that the neutron response of alanine was a sufficiently high fraction of the overall dosimeter response that the resulting uncertainties in the photon dose would be unacceptably large for silicon-device testing. However, it also suggested that non-hydrogenous materials such as polytetrafluoroethylene (PTFE) would exhibit smaller neutron response and might be useful in mixed environments. Preliminary research with PTFE in photon environments indicated considerable promise, but further development was not pursued at that time. Because of renewed interest in absorbed dose measurements that could better define the individual contributions of photon and neutron components to the overall dose delivered to a test object, the RML has re-initiated the development of an EPR/PTFE dosimetry system. This effort consists of three stages: 1) Identification of PTFE materials that may be suitable for dosimetry applications. It was speculated that the inconsistency of EPR signatures in the earlier samples may have been due to variability in PTFE manufacturing processes. 2) Characterization of dosimetry in

  20. A practical three-dimensional dosimetry system for radiation therapy

    SciTech Connect

    Guo Pengyi; Adamovics, John; Oldham, Mark

    2006-10-15

    There is a pressing need for a practical three-dimensional (3D) dosimetry system, convenient for clinical use, and with the accuracy and resolution to enable comprehensive verification of the complex dose distributions typical of modern radiation therapy. Here we introduce a dosimetry system that can achieve this challenge, consisting of a radiochromic dosimeter (PRESAGE trade mark sign ) and a commercial optical computed tomography (CT) scanning system (OCTOPUS trade mark sign ). PRESAGE trade mark sign is a transparent material with compelling properties for dosimetry, including insensitivity of the dose response to atmospheric exposure, a solid texture negating the need for an external container (reducing edge effects), and amenability to accurate optical CT scanning due to radiochromic optical contrast as opposed to light-scattering contrast. An evaluation of the performance and viability of the PRESAGE trade mark sign /OCTOPUS, combination for routine clinical 3D dosimetry is presented. The performance of the two components (scanner and dosimeter) was investigated separately prior to full system test. The optical CT scanner has a spatial resolution of {<=}1 mm, geometric accuracy within 1 mm, and high reconstruction linearity (with a R{sup 2} value of 0.9979 and a standard error of estimation of {approx}1%) relative to independent measurement. The overall performance of the PRESAGE trade mark sign /OCTOPUS system was evaluated with respect to a simple known 3D dose distribution, by comparison with GAFCHROMIC[reg] EBT film and the calculated dose from a commissioned planning system. The 'measured' dose distribution in a cylindrical PRESAGE trade mark sign dosimeter (16 cm diameter and 11 cm height) was determined by optical-CT, using a filtered backprojection reconstruction algorithm. A three-way Gamma map comparison (4% dose difference and 4 mm distance to agreement), between the PRESAGE trade mark sign , EBT and calculated dose distributions, showed full

  1. A practical three-dimensional dosimetry system for radiation therapy.

    PubMed

    Guo, Pengyi; Adamovics, John; Oldham, Mark

    2006-10-01

    There is a pressing need for a practical three-dimensional (3D) dosimetry system, convenient for clinical use, and with the accuracy and resolution to enable comprehensive verification of the complex dose distributions typical of modern radiation therapy. Here we introduce a dosimetry system that can achieve this challenge, consisting of a radiochromic dosimeter (PRESAGE) and a commercial optical computed tomography (CT) scanning system (OCTOPUS). PRESAGE is a transparent material with compelling properties for dosimetry, including insensitivity of the dose response to atmospheric exposure, a solid texture negating the need for an external container (reducing edge effects), and amenability to accurate optical CT scanning due to radiochromic optical contrast as opposed to light-scattering contrast. An evaluation of the performance and viability of the PRESAGE/OCTOPUS, combination for routine clinical 3D dosimetry is presented. The performance of the two components (scanner and dosimeter) was investigated separately prior to full system test. The optical CT scanner has a spatial resolution of < or = 1 mm, geometric accuracy within 1 mm, and high reconstruction linearity (with a R2 value of 0.9979 and a standard error of estimation of approximately 1%) relative to independent measurement. The overall performance of the PRESAGE/OCTOPUS system was evaluated with respect to a simple known 3D dose distribution, by comparison with GAFCHROMIC EBT film and the calculated dose from a commissioned planning system. The "measured" dose distribution in a cylindrical PRESAGE dosimeter (16 cm diameter and 11 cm height) was determined by optical-CT, using a filtered backprojection reconstruction algorithm. A three-way Gamma map comparison (4% dose difference and 4 mm distance to agreement), between the PRESAGE, EBT and calculated dose distributions, showed full agreement in measurable region of PRESAGE dosimeter (approximately 90% of radius). The EBT and PRESAGE distributions agreed

  2. The use of new GAFCHROMIC EBT film for {sup 125}I seed dosimetry in Solid Water phantom

    SciTech Connect

    Chiu-Tsao, Sou-Tung; Medich, David; Munro, John III

    2008-08-15

    Radiochromic film dosimetry has been extensively used for intravascular brachytherapy applications for near field within 1 cm from the sources. With the recent introduction of new model of radiochromic films, GAFCHROMIC EBT, with higher sensitivity than earlier models, it is promising to extend the distances out to 5 cm for low dose rate (LDR) source dosimetry. In this study, the use of new model GAFCHROMIC EBT film for {sup 125}I seed dosimetry in Solid Water was evaluated for radial distances from 0.06 cm out to 5 cm. A multiple film technique was employed for four {sup 125}I seeds (Implant Sciences model 3500) with NIST traceable air kerma strengths. Each experimental film was positioned in contact with a {sup 125}I seed in a Solid Water phantom. The products of the air kerma strength and exposure time ranged from 8 to 3158 U-h, with the initial air kerma strength of 6 U in a series of 25 experiments. A set of 25 calibration films each was sequentially exposed to one {sup 125}I seed at about 0.58 cm distance for doses from 0.1 to 33 Gy. A CCD camera based microdensitometer, with interchangeable green (520 nm) and red (665 nm) light boxes, was used to scan all the films with 0.2 mm pixel resolution. The dose to each {sup 125}I calibration film center was calculated using the air kerma strength of the seed (incorporating decay), exposure time, distance from seed center to film center, and TG43U1S1 recommended dosimetric parameters. Based on the established calibration curve, dose conversion from net optical density was achieved for each light source. The dose rate constant was determined as 0.991 cGy U{sup -1} h{sup -1} ({+-}6.9%) and 1.014 cGy U{sup -1} h{sup -1} ({+-}6.8%) from films scanned using green and red light sources, respectively. The difference between these two values was within the uncertainty of the measurement. Radial dose function and 2D anisotropy function were also determined. The results obtained using the two light sources corroborated each

  3. Peripheral red blood cell split chimerism as a consequence of intramedullary selective apoptosis of recipient red blood cells in a case of sickle cell disease.

    PubMed

    Marziali, Marco; Isgrò, Antonella; Sodani, Pietro; Gaziev, Javid; Fraboni, Daniela; Paciaroni, Katia; Gallucci, Cristiano; Alfieri, Cecilia; Roveda, Andrea; De Angelis, Gioia; Cardarelli, Luisa; Ribersani, Michela; Andreani, Marco; Lucarelli, Guido

    2014-01-01

    Allogeneic cellular gene therapy through hematopoietic stem cell transplantation is the only radical cure for congenital hemoglobinopathies like thalassemia and sickle cell anemia. Persistent mixed hematopoietic chimerism (PMC) has been described in thalassemia and sickle cell anemia. Here, we describe the clinical course of a 6-year-old girl who had received bone marrow transplant for sickle cell anemia. After the transplant, the patient showed 36% donor hematopoietic stem cells in the bone marrow, whereas in the peripheral blood there was evidence of 80% circulating donor red blood cells (RBC). The analysis of apoptosis at the Bone Marrow level suggests that Fas might contribute to the cell death of host erythroid precursors. The increase in NK cells and the regulatory T cell population observed in this patient suggests that these cells might contribute to the condition of mixed chimerism.

  4. TU-F-201-01: General Aspects of Radiochromic Film Dosimetry

    SciTech Connect

    Niroomand-Rad, A.

    2015-06-15

    Since the introduction of radiochromic films (RCF) for radiation dosimetry, the scope of RCF dosimetry has expanded steadily to include many medical applications, such as radiation therapy and diagnostic radiology. The AAPM Task Group (TG) 55 published a report on the recommendations for RCF dosimetry in 1998. As the technology is advancing rapidly, and its routine clinical use is expanding, TG 235 has been formed to provide an update to TG-55 on radiochromic film dosimetry. RCF dosimetry applications in clinical radiotherapy have become even more widespread, expanding from primarily brachytherapy and radiosurgery applications, and gravitating towards (but not limited to) external beam therapy (photon, electron and protons), such as quality assurance for IMRT, VMAT, Tomotherapy, SRS/SRT, and SBRT. In addition, RCF applications now extend to measurements of radiation dose in particle beams and patients undergoing medical exams, especially fluoroscopically guided interventional procedures and CT. The densitometers/scanners used for RCF dosimetry have also evolved from the He-Ne laser scanner to CCD-based scanners, including roller-based scanner, light box-based digital camera, and flatbed color scanner. More recently, multichannel RCF dosimetry introduced a new paradigm for external beam dose QA for its high accuracy and efficiency. This course covers in detail the recent advancements in RCF dosimetry. Learning Objectives: Introduce the paradigm shift on multichannel film dosimetry Outline the procedures to achieve accurate dosimetry with a RCF dosimetry system Provide comprehensive guidelines on RCF dosimetry for various clinical applications One of the speakers has a research agreement from Ashland Inc., the manufacturer of Gafchromic film.

  5. The US Department of Energy Personnel Dosimetry Evaluation and Upgrade Program

    SciTech Connect

    Faust, L.G.; Stroud, C.M.; Swinth, K.L.; Vallario, E.J.

    1987-11-01

    The US Department of Energy (DOE) Personnel Dosimetry Evaluation and Upgrade Program is designed to identify and evaluate dosimetry deficiencies and to conduct innovative research and development programs that will improve overall capabilities, thus ensuring that DOE can comply with applicable standards and regulations for dose measurement. To achieve these goals, two programs were initiated to evaluate and upgrade beta measurement and neutron dosimetry. 3 refs.

  6. Magnetic resonance imaging of the spinal marrow: Basic understanding of the normal marrow pattern and its variant

    PubMed Central

    Nouh, Mohamed Ragab; Eid, Ahmed Fathi

    2015-01-01

    For now, magnetic resonance (MR) is the best noninvasive imaging modality to evaluate vertebral bone marrow thanks to its inherent soft-tissue contrast and non-ionizing nature. A daily challenging scenario for every radiologist interpreting MR of the vertebral column is discerning the diseased from normal marrow. This requires the radiologist to be acquainted with the used MR techniques to judge the spinal marrow as well as its normal MR variants. Conventional sequences used basically to image marrow include T1W, fat-suppressed T2W and short tau inversion recovery (STIR) imaging provides gross morphological data. Interestingly, using non-routine MR sequences; such as opposed phase, diffusion weighted, MR spectroscopy and contrasted-enhanced imaging; may elucidate the nature of bone marrow heterogeneities; by inferring cellular and chemical composition; and adding new functional prospects. Recalling the normal composition of bone marrow elements and the physiologic processes of spinal marrow conversion and reconversion eases basic understanding of spinal marrow imaging. Additionally, orientation with some common variants seen during spinal marrow MR imaging as hemangiomas and bone islands is a must. Moreover, awareness of the age-associated bone marrow changes as well as changes accompanying different variations of the subject’s health state is essential for radiologists to avoid overrating normal MR marrow patterns as pathologic states and metigate unnecessary further work-up. PMID:26753060

  7. Phantom Positioning Variation in the Gamma Knife® Perfexion Dosimetry

    NASA Astrophysics Data System (ADS)

    Costa, N. A.; Potiens, M. P. A.; Saraiva, C. W. C.

    2016-07-01

    The use of small volume ionization chamber has become required for the dosimetry of equipments that use small radiation fields such as the Gamma Knife® Perfexion (GKP) unit. In this work, a pinpoint ionization chamber was inserted into the dosimetry phantom and measurements were performed with the phantom in different positions, in order to verify if the change in the phantom positioning affects the dosimetry of the GKP. Four different phantom positions were performed. The variation in the result is within the range allowed for the dosimetry of a GKP equipment.

  8. Handbook for the Department of Energy Laboratory Accreditation Program for personnel dosimetry systems

    SciTech Connect

    Not Available

    1986-12-01

    The program contained in this Handbook provides a significant advance in the field of radiation protection through a structured means for assuring the quality of personnel dosimetry performance. Since personnel dosimetry performance is directly related to the assurance of worker safety, it has been of key interest to the Department of Energy. Studies conducted over the past three decades have clearly demonstrated a need for personnel dosimetry performance criteria, related testing programs, and improvements in dosimetry technology. In responding to these needs, the DOE Office of Nuclear Safety (EH) has developed and initiated a DOE Laboratory Accreditation Program (DOELAP) which is intended to improve the quality of personnel dosimetry through (1) performance testing, (2) dosimetry and calibration intercomparisons, and (3) applied research. In the interest of improving dosimetry technology, the DOE Laboratory Accreditation Program (DOELAP) is also designed to encourage cooperation and technical interchange between DOE laboratories. Dosimetry intercomparison programs have been scheduled which include the use of transport standard instruments, transport standard radioactive sources and special dosimeters. The dosimeters used in the intercomparison program are designed to obtain optimum data on the comparison of dosimetry calibration methodologies and capabilities. This data is used in part to develop enhanced calibration protocols. In the interest of overall calibration update, assistance and guidance for the calibration of personnel dosimeters is available through the DOELAP support laboratories. 20 refs., 1 tab.

  9. Dosimetry using environmental and biological materials. Final report

    SciTech Connect

    Haskell, E.; Kenner, G.; Hayes, R.

    1998-02-01

    This report summarizes a five year effort to improve the sensitivity and reliability of retrospective dosimetry methods, to collaborate with laboratories engaged in related research and to share the technology with startup laboratories seeking similar capabilities. This research program has focused on validation of electron paramagnetic resonance (EPR) as a dosimetry tool and on optimization of the technique by reducing the lower limits of detection, simplifying the process of sample preparation and analysis and speeding analysis to allow greater throughput in routine measurement situations. The authors have investigated the dosimetric signal of hard tissues in enamel, deorganified dentin, synthetic carbonated apatites and synthetic hydroxyapatite. This research has resulted in a total of 27 manuscripts which have been published, are in press, or have been submitted for publication. Of these manuscripts, 14 are included in this report and were indexed separately for inclusion in the data base.

  10. NCRP PROGRAM AREA COMMITTEE 6: RADIATION DOSIMETRY AND MEASUREMENTS

    PubMed Central

    Simon, Steven L.; Zeman, Gary H.

    2015-01-01

    Program Area Committee (PAC) 6 of the National Council on Radiation Protection and Measurements provides guidance for radiation measurements and dosimetry – one of the most fundamental scientific areas of the Council’s expertise. Seminal reports published by PAC 6 over many decades have documented the scientific and technical foundations of radiation measurements and dosimetry for generations of radiation scientists and radiation protection professionals. Ongoing work of PAC 6 is driven by advancing technology such as development of new types of instruments, biodosimetry and nanotechnology; by evolving understanding of radiation hazards such as effects on lens of the eye, and risks as from some high-dose medical imaging procedures; and by new situations faced in the modern socio-political environment including radiological and nuclear threats. The activities of PAC 6 are intended to formulate and document the dosimetric framework for radiological science to address these ever emerging challenges. PMID:26717161

  11. A new technique for dosimetry reaction cross-section evaluation

    SciTech Connect

    Badikov, S.A.

    2011-07-01

    Document available in abstract form only, full text of document follows: An objective of this paper is a unification of the procedure for dosimetry reaction cross-section evaluation. A set of requirements for the unified evaluation procedure is presented. A new code (ORTHO) was developed in order to meet these requirements. A statistical model, an algorithm, and the basic formulae employed in the code are described. The code was used for Ti48(n,p) reaction cross-section evaluation. The results of the evaluation are compared to International Reactor Dosimetry File (IRDF)-2002 data. The evaluated cross-sections and their correlations from this work are in good agreement with the IRDF-2002 evaluated data, whereas the uncertainties of the evaluated cross-sections are inconsistent. (authors)

  12. Advanced dosimetry systems for the space transport and space station

    NASA Technical Reports Server (NTRS)

    Wailly, L. F.; Schneider, M. F.; Clark, B. C.

    1972-01-01

    Advanced dosimetry system concepts are described that will provide automated and instantaneous measurement of dose and particle spectra. Systems are proposed for measuring dose rate from cosmic radiation background to greater than 3600 rads/hr. Charged particle spectrometers, both internal and external to the spacecraft, are described for determining mixed field energy spectra and particle fluxes for both real time onboard and ground-based computer evaluation of the radiation hazard. Automated passive dosimetry systems consisting of thermoluminescent dosimeters and activation techniques are proposed for recording the dose levels for twelve or more crew members. This system will allow automatic onboard readout and data storage of the accumulated dose and can be transmitted to ground after readout or data records recovered with each crew rotation.

  13. NCRP Program Area Committee 6: Radiation Measurements and Dosimetry.

    PubMed

    Simon, Steven L; Zeman, Gary H

    2016-02-01

    Program Area Committee (PAC) 6 of the National Council on Radiation Protection and Measurements provides guidance for radiation measurements and dosimetry--one of the most fundamental scientific areas of the Council's expertise. Seminal reports published by PAC 6 over many decades have documented the scientific and technical foundations of radiation measurements and dosimetry for generations of radiation scientists and radiation protection professionals. Ongoing work of PAC 6 is driven by advancing technology, such as development of new types of instruments, biodosimetry and nanotechnology; by evolving understanding of radiation hazards, such as effects on the lens of the eye and risks as from some high-dose medical imaging procedures; and by new situations faced in the modern socio-political environment including radiological and nuclear threats. The activities of PAC 6 are intended to formulate and document the dosimetric framework for radiological science to address these ever-emerging challenges.

  14. The specifics of dosimetry for food irradiation applications

    NASA Astrophysics Data System (ADS)

    Kuntz, Florent; Strasser, Alain

    2016-12-01

    Dose measurement applied to food irradiation is obviously a very important and critical aspect of this process. It is described in many standards and guides. The application of appropriate dosimetry tools is explained. This helps to ensure traceability of this measurement and number of dosimeters available on the market are well studied even though theirs response should be characterized while used in routine processing conditions. When employed in low energy radiation fields, these dosimeters may exhibit specific response compared to the usual Cobalt 60 source irradiation. Traceable calibration or correction factor assessment of this energy dependency is mandatory. It is to mention that the absorbed dose is measured in the dosimeter itself and unfortunately not in/on the food product. However, existing dosimetry systems fulfill all relevant requirements.

  15. Methods and computer readable medium for improved radiotherapy dosimetry planning

    DOEpatents

    Wessol, Daniel E.; Frandsen, Michael W.; Wheeler, Floyd J.; Nigg, David W.

    2005-11-15

    Methods and computer readable media are disclosed for ultimately developing a dosimetry plan for a treatment volume irradiated during radiation therapy with a radiation source concentrated internally within a patient or incident from an external beam. The dosimetry plan is available in near "real-time" because of the novel geometric model construction of the treatment volume which in turn allows for rapid calculations to be performed for simulated movements of particles along particle tracks therethrough. The particles are exemplary representations of alpha, beta or gamma emissions emanating from an internal radiation source during various radiotherapies, such as brachytherapy or targeted radionuclide therapy, or they are exemplary representations of high-energy photons, electrons, protons or other ionizing particles incident on the treatment volume from an external source. In a preferred embodiment, a medical image of a treatment volume irradiated during radiotherapy having a plurality of pixels of information is obtained.

  16. Radiation accident dosimetry on plastics by EPR spectrometry.

    PubMed

    Trompier, F; Bassinet, C; Clairand, I

    2010-02-01

    In case of acute exposure to ionizing radiation, the dose absorbed by the victims has to be rapidly and accurately assessed in order to choose an appropriate medical treatment. Tooth enamel and bone biopsies measured by EPR spectrometry are often used as dose indicators, due to the good radiation sensitivity and the stability of EPR radiation-sensitive signals. Nevertheless, the invasive sampling of teeth and bones limits the application of this technique to retrospective dosimetry. Therefore, we have investigated an alternative non-invasive methodology. We have surveyed with EPR spectrometry the dosimetric properties of the plastics that can be found in personal effects such as glasses (CR-39, polycarbonate), mobile phones (PMMA, polycarbonate), watches and buttons. Dose response, signal stability and effects of storage conditions were investigated. Significant signal fading limits the use for radiation accident dosimetry. Few plastics present the required characteristics to be used in case of a radiation accident.

  17. Clinical applications of alanine/electron spin resonance dosimetry.

    PubMed

    Baffa, Oswaldo; Kinoshita, Angela

    2014-05-01

    This paper discusses the clinical applications of electron spin resonance (ESR) dosimetry focusing on the ESR/alanine system. A review of few past studies in this area is presented offering a critical overview of the challenges and opportunities for extending this system into clinical applications. Alanine/ESR dosimetry fulfills many of the required properties for several clinical applications such as water-equivalent composition, independence of the sensitivity for the energy range used in therapy and high precision. Improvements in sensitivity and the development of minidosimeters coupled with the use of a spectrometer of higher microwave frequency expanded the possibilities for clinical applications to the new modalities of radiotherapy (intensity-modulated radiation therapy and radiosurgery) and to the detection of low doses such as those present in some radiological image procedures.

  18. Latest developments in silica-based thermoluminescence spectrometry and dosimetry.

    PubMed

    Bradley, D A; Jafari, S M; Siti Shafiqah, A S; Tamcheck, N; Shutt, A; Siti Rozaila, Z; Abdul Sani, S F; Sabtu, Siti Norbaini; Alanazi, Abdulaziz; Amouzad Mahdiraji, G; Abdul Rashid, H A; Maah, M J

    2016-11-01

    Using irradiated doped-silica preforms from which fibres for thermoluminescence dosimetry applications can be fabricated we have carried out a range of luminescence studies, the TL yield of the fibre systems offering many advantages over conventional passive dosimetry types. In this paper we investigate such media, showing emission spectra for irradiated preforms and the TL response of glass beads following irradiation to an (241)Am-Be neutron source located in a tank of water, the glass fibres and beads offering the advantage of being able to be placed directly into liquid. The outcomes from these and other lines of research are intended to inform development of doped silica radiation dosimeters of versatile utility, extending from environmental evaluations through to clinical and industrial applications.

  19. KCl:Dy phosphor for thermoluminescence dosimetry of ionizing radiation.

    PubMed

    Bhujbal, P M; Dhoble, S J

    2013-01-01

    The thermoluminescence (TL) characterizations of γ-irradiated KCl:Dy phosphor for radiation dosimetry are reported. All phosphors were synthesized via a wet chemical route. Minimum fading of TL intensity is recorded in the prepared material. TL in samples containing different concentrations of Dy impurity was studied at different γ-irradiation doses. Peak TL intensities varied sublinearly with γ-ray dose in all samples, but were linear between 0.08 to 0.75 kGy for the KCl:Dy (0.1 mol%) sample. This material may be useful for dosimetry within this range of γ-ray dose. TL peak height was found to be dependant on the concentration (0.05-0.5 mol%) of added Dy in the host.

  20. Computer simulations for internal dosimetry using voxel models.

    PubMed

    Kinase, Sakae; Mohammadi, Akram; Takahashi, Masa; Saito, Kimiaki; Zankl, Maria; Kramer, Richard

    2011-07-01

    In the Japan Atomic Energy Agency, several studies have been conducted on the use of voxel models for internal dosimetry. Absorbed fractions (AFs) and S values have been evaluated for preclinical assessments of radiopharmaceuticals using human voxel models and a mouse voxel model. Computational calibration of in vivo measurement system has been also made using Japanese and Caucasian voxel models. In addition, for radiation protection of the environment, AFs have been evaluated using a frog voxel model. Each study was performed by using Monte Carlo simulations. Consequently, it was concluded that these data of Monte Carlo simulations and voxel models could adequately reproduce measurement results. Voxel models were found to be a significant tool for internal dosimetry since the models are anatomically realistic. This fact indicates that several studies on correction of the in vivo measurement efficiency for the variability of human subjects and interspecies scaling of organ doses will succeed.

  1. Education and training activities on personal dosimetry service in Turkey.

    PubMed

    Tugrul Zeyrek, C; Akbiyik, Hayri

    2013-10-01

    A personal dosimetry service that evaluates the occupational doses for external and internal radiation of the radiation workers is one of the main components of radiation protection programme. The education and training (E&T) activities in this field are basic aspects of the optimisation of all exposures to radiation. The E&T activities in the field of occupational radiation protection at the national and international level are of main interest and implemented by the Ankara Nuclear Research and Training Center. This study describes the Turkish experience in E&T of the staff of dosimetry services, postgraduate students and medical physics experts. In Turkey, the first individual monitoring training course was conducted in 2012. The aim of this study is to provide a structured description of postgraduate courses that are addressed to qualified experts and medical physics experts, and the modules are mainly dedicated to individual monitoring.

  2. ACS Algorithm in Discrete Ordinates for Pressure Vessel Dosimetry

    NASA Astrophysics Data System (ADS)

    Walters, William; Haghighat, Alireza

    2016-02-01

    The Adaptive Collision Source (ACS) method can solve the Linear Boltzmann Equation (LBE) more efficiently by adaptation of the angular quadrature order. This is similar to, and essentially an extension of, the first collision source method. Previously, the ACS methodology has been implemented into the TITAN discrete ordinates code, and has shown speedups of 2-4 on a simple test problem, with very little loss of accuracy (within a provided adaptive tolerance). This work examines the use of the ACS method for a more realistic problem: pressure vessel dosimetry with the VENUS-2 MOX-fuelled reactor dosimetry benchmark. The ACS method proved to be able to obtain accurate results while being approximately twice as efficient as using a constant quadrature in a standard source iteration scheme.

  3. Consistency of external dosimetry in epidemiologic studies of nuclear workers

    SciTech Connect

    Fix, J.J.; Gilbert, E.S.

    1991-10-01

    To make the best use of available epidemiologic data in assessing risks from exposure to low-level radiation, it is important that biases and uncertainties in estimated doses be understood and documented. With this understanding, analyses of mortality data can be strengthened by including the use of correction factors where judged appropriate, excluding portions of the data where uncertainty in dose estimates is judged to be very large, and conducting sensitivity analyses to examine the effect of alternative assumptions about dosimetry errors and biases on results. It is hoped that the pooling of data from several epidemiologic studies and improved understanding of dosimetry will lead to better estimates of radiation risks. 10 refs., 4 tabs.

  4. EPR dosimetry in a mixed neutron and gamma radiation field.

    PubMed

    Trompier, F; Fattibene, P; Tikunov, D; Bartolotta, A; Carosi, A; Doca, M C

    2004-01-01

    Suitability of Electron Paramagnetic Resonance (EPR) spectroscopy for criticality dosimetry was evaluated for tooth enamel, mannose and alanine pellets during the 'international intercomparison of criticality dosimetry techniques' at the SILENE reactor held in Valduc in June 2002, France. These three materials were irradiated in neutron and gamma-ray fields of various relative intensities and spectral distributions in order to evaluate their neutron sensitivity. The neutron response was found to be around 10% for tooth enamel, 45% for mannose and between 40 and 90% for alanine pellets according their type. According to the IAEA recommendations on the early estimate of criticality accident absorbed dose, analyzed results show the EPR potentiality and complementarity with regular criticality techniques.

  5. The effect of autologous bone marrow stromal cells differentiated on scaffolds for canine tibial bone reconstruction.

    PubMed

    Özdal-Kurt, F; Tuğlu, I; Vatansever, H S; Tong, S; Deliloğlu-Gürhan, S I

    2015-01-01

    Bone marrow contains mesenchymal stem cells that form many tissues. Various scaffolds are available for bone reconstruction by tissue engineering. Osteoblastic differentiated bone marrow stromal cells (BMSC) promote osteogenesis on scaffolds and stimulate bone regeneration. We investigated the use of cultured autologous BMSC on different scaffolds for healing defects in tibias of adult male canines. BMSC were isolated from canine humerus bone marrow, differentiated into osteoblasts in culture and loaded onto porous ceramic scaffolds including hydroxyapatite 1, hydroxyapatite gel and calcium phosphate. Osteoblast differentiation was verified by osteonectine and osteocalcine immunocytochemistry. The scaffolds with stromal cells were implanted in the tibial defect. Scaffolds without stromal cells were used as controls. Sections from the defects were processed for histological, ultrastructural, immunohistochemical and histomorphometric analyses to analyze the healing of the defects. BMSC were spread, allowed to proliferate and differentiate to osteoblasts as shown by alizarin red histochemistry, and osteocalcine and osteonectine immunostaining. Scanning electron microscopy showed that BMSC on the scaffolds were more active and adhesive to the calcium phosphate scaffold compared to the others. Macroscopic bone formation was observed in all groups, but scaffolds with stromal cells produced significantly better results. Bone healing occurred earlier and faster with stromal cells on the calcium phosphate scaffold and produced more callus compared to other scaffolds. Tissue healing and osteoblastic marker expression also were better with stromal cells on the scaffolds. Increased trabecula formation, cell density and decreased fibrosis were observed in the calcium phosphate scaffold with stromal cells. Autologous cultured stromal cells on the scaffolds were useful for healing of canine tibial bone defects. The calcium phosphate scaffold was the best for both cell

  6. Shared Dosimetry Error in Epidemiological Dose-Response Analyses

    PubMed Central

    Stram, Daniel O.; Preston, Dale L.; Sokolnikov, Mikhail; Napier, Bruce; Kopecky, Kenneth J.; Boice, John; Beck, Harold; Till, John; Bouville, Andre

    2015-01-01

    Radiation dose reconstruction systems for large-scale epidemiological studies are sophisticated both in providing estimates of dose and in representing dosimetry uncertainty. For example, a computer program was used by the Hanford Thyroid Disease Study to provide 100 realizations of possible dose to study participants. The variation in realizations reflected the range of possible dose for each cohort member consistent with the data on dose determinates in the cohort. Another example is the Mayak Worker Dosimetry System 2013 which estimates both external and internal exposures and provides multiple realizations of "possible" dose history to workers given dose determinants. This paper takes up the problem of dealing with complex dosimetry systems that provide multiple realizations of dose in an epidemiologic analysis. In this paper we derive expected scores and the information matrix for a model used widely in radiation epidemiology, namely the linear excess relative risk (ERR) model that allows for a linear dose response (risk in relation to radiation) and distinguishes between modifiers of background rates and of the excess risk due to exposure. We show that treating the mean dose for each individual (calculated by averaging over the realizations) as if it was true dose (ignoring both shared and unshared dosimetry errors) gives asymptotically unbiased estimates (i.e. the score has expectation zero) and valid tests of the null hypothesis that the ERR slope β is zero. Although the score is unbiased the information matrix (and hence the standard errors of the estimate of β) is biased for β≠0 when ignoring errors in dose estimates, and we show how to adjust the information matrix to remove this bias, using the multiple realizations of dose. The use of these methods in the context of several studies including, the Mayak Worker Cohort, and the U.S. Atomic Veterans Study, is discussed. PMID:25799311

  7. Dosimetry and microdosimetry using COTS ICs: A comparative study

    NASA Technical Reports Server (NTRS)

    Scheick, L.; Swift, G.; Guertin, S.; Roth, D.; McNulty, P.; Nguyen, D.

    2002-01-01

    A new method using an array of MOS transistors formeasuring dose absorbed from ionizing radiation is compared to previous dosimetric methods., The accuracy and precision of dosimetry based on COTS SRAMs, DRAMs, and WPROMs are compared and contrasted. Applications of these devices in various space missions will be discussed. TID results are presented for this summary and microdosimetricresults will be added to the full paper. Finally, an analysis of the optimal condition for a digital dosimeter will be presented.

  8. Optimization of the double dosimetry algorithm for interventional cardiologists

    NASA Astrophysics Data System (ADS)

    Chumak, Vadim; Morgun, Artem; Bakhanova, Elena; Voloskiy, Vitalii; Borodynchik, Elena

    2014-11-01

    A double dosimetry method is recommended in interventional cardiology (IC) to assess occupational exposure; yet currently there is no common and universal algorithm for effective dose estimation. In this work, flexible and adaptive algorithm building methodology was developed and some specific algorithm applicable for typical irradiation conditions of IC procedures was obtained. It was shown that the obtained algorithm agrees well with experimental measurements and is less conservative compared to other known algorithms.

  9. Radiochromic Film Dosimetry and its Applications in Radiotherapy

    SciTech Connect

    Williams, Matthew; Metcalfe, Peter

    2011-05-05

    Radiochromic film can be a fast and inexpensive means for performing accurate quantitative radiation dosimetry. The development of new radiochromic compositions that have greater dose sensitivity and fewer environmental dependencies has led to an ever increasing use of the film in radiotherapy applications. In this report the various physical and dosimetric properties of radiochromic film are presented and the strategies to adequately manage these properties when using radiochromic film for radiotherapy applications are discussed.

  10. Shared dosimetry error in epidemiological dose-response analyses

    DOE PAGES

    Stram, Daniel O.; Preston, Dale L.; Sokolnikov, Mikhail; ...

    2015-03-23

    Radiation dose reconstruction systems for large-scale epidemiological studies are sophisticated both in providing estimates of dose and in representing dosimetry uncertainty. For example, a computer program was used by the Hanford Thyroid Disease Study to provide 100 realizations of possible dose to study participants. The variation in realizations reflected the range of possible dose for each cohort member consistent with the data on dose determinates in the cohort. Another example is the Mayak Worker Dosimetry System 2013 which estimates both external and internal exposures and provides multiple realizations of "possible" dose history to workers given dose determinants. This paper takesmore » up the problem of dealing with complex dosimetry systems that provide multiple realizations of dose in an epidemiologic analysis. In this paper we derive expected scores and the information matrix for a model used widely in radiation epidemiology, namely the linear excess relative risk (ERR) model that allows for a linear dose response (risk in relation to radiation) and distinguishes between modifiers of background rates and of the excess risk due to exposure. We show that treating the mean dose for each individual (calculated by averaging over the realizations) as if it was true dose (ignoring both shared and unshared dosimetry errors) gives asymptotically unbiased estimates (i.e. the score has expectation zero) and valid tests of the null hypothesis that the ERR slope β is zero. Although the score is unbiased the information matrix (and hence the standard errors of the estimate of β) is biased for β≠0 when ignoring errors in dose estimates, and we show how to adjust the information matrix to remove this bias, using the multiple realizations of dose. The use of these methods in the context of several studies including, the Mayak Worker Cohort, and the U.S. Atomic Veterans Study, is discussed.« less

  11. Shared Dosimetry Error in Epidemiological Dose-Response Analyses

    SciTech Connect

    Stram, Daniel O.; Preston, Dale L.; Sokolnikov, Mikhail; Napier, Bruce; Kopecky, Kenneth J.; Boice, John; Beck, Harold; Till, John; Bouville, Andre; Zeeb, Hajo

    2015-03-23

    Radiation dose reconstruction systems for large-scale epidemiological studies are sophisticated both in providing estimates of dose and in representing dosimetry uncertainty. For example, a computer program was used by the Hanford Thyroid Disease Study to provide 100 realizations of possible dose to study participants. The variation in realizations reflected the range of possible dose for each cohort member consistent with the data on dose determinates in the cohort. Another example is the Mayak Worker Dosimetry System 2013 which estimates both external and internal exposures and provides multiple realizations of "possible" dose history to workers given dose determinants. This paper takes up the problem of dealing with complex dosimetry systems that provide multiple realizations of dose in an epidemiologic analysis. In this paper we derive expected scores and the information matrix for a model used widely in radiation epidemiology, namely the linear excess relative risk (ERR) model that allows for a linear dose response (risk in relation to radiation) and distinguishes between modifiers of background rates and of the excess risk due to exposure. We show that treating the mean dose for each individual (calculated by averaging over the realizations) as if it was true dose (ignoring both shared and unshared dosimetry errors) gives asymptotically unbiased estimates (i.e. the score has expectation zero) and valid tests of the null hypothesis that the ERR slope β is zero. Although the score is unbiased the information matrix (and hence the standard errors of the estimate of β) is biased for β≠0 when ignoring errors in dose estimates, and we show how to adjust the information matrix to remove this bias, using the multiple realizations of dose. Use of these methods for several studies, including the Mayak Worker Cohort and the U.S. Atomic Veterans Study, is discussed.

  12. Radiological protection and medical dosimetry for the Skylab crewmen

    NASA Technical Reports Server (NTRS)

    Bailey, J. V.; Hoffman, R. A.; English, R. A.

    1977-01-01

    Dosimetry results for Skylab crewmembers show that the Skylab 4 crewmen received the highest dose equivalents but remained well within the established limits for Skylab missions below the threshold of significant clinical effects. These dose equivalents apply specificially to long term effects such as general life shortening, increased neoplasm incidence, and cataract production. A Skylab crewman could fly a mission comparable to one 84-day Skylab 4 mission per year for 50 years before exceeding these career limits.

  13. Shared dosimetry error in epidemiological dose-response analyses

    SciTech Connect

    Stram, Daniel O.; Preston, Dale L.; Sokolnikov, Mikhail; Napier, Bruce; Kopecky, Kenneth J.; Boice, John; Beck, Harold; Till, John; Bouville, Andre; Zeeb, Hajo

    2015-03-23

    Radiation dose reconstruction systems for large-scale epidemiological studies are sophisticated both in providing estimates of dose and in representing dosimetry uncertainty. For example, a computer program was used by the Hanford Thyroid Disease Study to provide 100 realizations of possible dose to study participants. The variation in realizations reflected the range of possible dose for each cohort member consistent with the data on dose determinates in the cohort. Another example is the Mayak Worker Dosimetry System 2013 which estimates both external and internal exposures and provides multiple realizations of "possible" dose history to workers given dose determinants. This paper takes up the problem of dealing with complex dosimetry systems that provide multiple realizations of dose in an epidemiologic analysis. In this paper we derive expected scores and the information matrix for a model used widely in radiation epidemiology, namely the linear excess relative risk (ERR) model that allows for a linear dose response (risk in relation to radiation) and distinguishes between modifiers of background rates and of the excess risk due to exposure. We show that treating the mean dose for each individual (calculated by averaging over the realizations) as if it was true dose (ignoring both shared and unshared dosimetry errors) gives asymptotically unbiased estimates (i.e. the score has expectation zero) and valid tests of the null hypothesis that the ERR slope β is zero. Although the score is unbiased the information matrix (and hence the standard errors of the estimate of β) is biased for β≠0 when ignoring errors in dose estimates, and we show how to adjust the information matrix to remove this bias, using the multiple realizations of dose. The use of these methods in the context of several studies including, the Mayak Worker Cohort, and the U.S. Atomic Veterans Study, is discussed.

  14. Shared dosimetry error in epidemiological dose-response analyses.

    PubMed

    Stram, Daniel O; Preston, Dale L; Sokolnikov, Mikhail; Napier, Bruce; Kopecky, Kenneth J; Boice, John; Beck, Harold; Till, John; Bouville, Andre

    2015-01-01

    Radiation dose reconstruction systems for large-scale epidemiological studies are sophisticated both in providing estimates of dose and in representing dosimetry uncertainty. For example, a computer program was used by the Hanford Thyroid Disease Study to provide 100 realizations of possible dose to study participants. The variation in realizations reflected the range of possible dose for each cohort member consistent with the data on dose determinates in the cohort. Another example is the Mayak Worker Dosimetry System 2013 which estimates both external and internal exposures and provides multiple realizations of "possible" dose history to workers given dose determinants. This paper takes up the problem of dealing with complex dosimetry systems that provide multiple realizations of dose in an epidemiologic analysis. In this paper we derive expected scores and the information matrix for a model used widely in radiation epidemiology, namely the linear excess relative risk (ERR) model that allows for a linear dose response (risk in relation to radiation) and distinguishes between modifiers of background rates and of the excess risk due to exposure. We show that treating the mean dose for each individual (calculated by averaging over the realizations) as if it was true dose (ignoring both shared and unshared dosimetry errors) gives asymptotically unbiased estimates (i.e. the score has expectation zero) and valid tests of the null hypothesis that the ERR slope β is zero. Although the score is unbiased the information matrix (and hence the standard errors of the estimate of β) is biased for β≠0 when ignoring errors in dose estimates, and we show how to adjust the information matrix to remove this bias, using the multiple realizations of dose. The use of these methods in the context of several studies including, the Mayak Worker Cohort, and the U.S. Atomic Veterans Study, is discussed.

  15. Total body irradiation in bone marrow transplantation: the influence of fractionation and delay of marrow infusion

    SciTech Connect

    Lichter, A.S.; Tracy, D.; Lam, W.C.; Order, S.E.

    1980-03-01

    Bone marrow transplantation (BMT) after total body irradiation (TBI) and cyclophosphamide is being employed increasingly in the therapy of end stage leukemia. Interstitial pneumonitis (IP) represents a major acute toxicity after allogeneic transplantation. A more rapid reconstitution of lymphoid organs and bone marrow post transplant may result in increased immune competence and hence fewer opportunistic pulmonary infections and IP. By delaying the infusion of marrow to 72 hr after TBI (1250 rad at 7.5 rad/min) instead of the customary 24 hr, we can demonstrate an increase in initial repopulation of thymus, spleen and bone marrow, with syngeneic transplants in Lewis rats. Interstitial pneumonitis may also be caused, in part, by the pulmonary toxicity of large single exposures of TBI. Clinical and laboratory data suggest that fractionated TBI may be less toxic to the lung. When fractionated TBI (625 rad x 2, 7.5 rad/min) is compared to single dose TBI (1250 rad, 7.5 rad/min), and increased initial repopulation of lymphoid organs is observed when fractionated therapy is employed. Delay in marrow infusion and fractionation of TBI exposure may have clinical advantages in patients who receive BMT.

  16. Pharmacokinetics and red cell utilization of 52Fe/59Fe-labelled iron polymaltose in anaemic patients using positron emission tomography.

    PubMed

    Beshara, Soheir; Sörensen, Jens; Lubberink, Mark; Tolmachev, Vladimir; Långström, Bengt; Antoni, Gunnar; Danielson, Bo G; Lundqvist, Hans

    2003-03-01

    Parenteral iron-polysaccharide complexes are increasingly applied. The pharmacokinetics of iron sucrose have been assessed by our group using positron emission tomography (PET). A single intravenous injection of 100 mg iron as iron (III) hydroxide-polymaltose complex, labelled with a tracer in the form of 52Fe/59Fe, was similarly assessed in six patients using PET for about 8 h. Red cell utilization was followed for 4 weeks. Iron polymaltose was similarly distributed to the liver, spleen and bone marrow. However, a larger proportion of this complex was rapidly distributed to the bone marrow. The shorter equilibration phase for the liver, about 25 min, indicates the minimal role of the liver for direct distribution. Splenic uptake also reflected the reticuloendothelial handling of this complex. Red cell utilization ranged from 61% to 99%. Despite the relatively higher uptake by the bone marrow, there was no saturation of marrow transport systems at this dose level. In conclusion, high red cell utilization of iron polymaltose occurred in anaemic patients. The major portion of the injected dose was rapidly distributed to the bone marrow. In addition, the reticuloendothelial uptake of this complex may reflect the safety of polysaccharide complexes. Non-saturation of transport systems to the bone marrow indicated the presence of a large interstitial transport pool, which might possibly be transferrin.

  17. Verification of total body photon irradiation dosimetry techniques

    SciTech Connect

    Kirby, T.H.; Hanson, W.F.; Cates, D.A.

    1988-05-01

    A method of verifying the dosimetry of patients undergoing total body irradiation (TBI) with photon beams having energies from cobalt-60 to 25 MV is presented. A simple set of spot checks at the TBI axis has been used to verify data used for TBI dosimetry. Calculations to verify dose delivered to TBI patients are done in the same manner as those irradiated at standard treatment distances. A simple method of effective field size determination for various anatomical locations in a typical adult is presented. Measurements in an Alderson phantom with thermoluminescent dosimeters and an ion chamber at several anatomical locations indicate that this calculational method can predict the dose along the patient axis to within 4% for /sup 60/Co and 18-MV photon beams, provided the dosimetry data are appropriate (as determined by the spot checks). Results of intercomparisons of TBI beam calibration, off-axis and depth-dose data at various institutions visited by the Radiological Physics Center are also presented.

  18. International cooperative effort to establish dosimetry standardization for radiation processing

    SciTech Connect

    Farrar, H. IV

    1989-01-01

    Radiation processing is a rapidly developing technology with numerous applications in food treatment, sterilization, and polymer modification. The effectiveness of the process depends, however, on the proper application of dose and its measurement. These aspects are being considered by a wide group of experts from around the world who have joined together to write a comprehensive set of standards for dosimetry for radiation processing. Originally formed in 1984 to develop standards for food processing dosimetry, the group has now expanded into a full subcommittee of the American Society for Testing and Materials (ASTM), with 97 members from 19 countries. The scope of the standards now includes dosimetry for all forms of radiation processing. The group has now completed and published four standards, and is working on an additional seven. Three are specifically for food applications and the others are for all radiation applications, including food processing. Together, this set of standards will specify acceptable guidelines and methods for accomplishing the required irradiation treatment, and will be available for adoption by national regulatory agencies in their procedures and protocols. 1 tab.

  19. A small-scale anatomical dosimetry model of the liver

    NASA Astrophysics Data System (ADS)

    Stenvall, Anna; Larsson, Erik; Strand, Sven-Erik; Jönsson, Bo-Anders

    2014-07-01

    Radionuclide therapy is a growing and promising approach for treating and prolonging the lives of patients with cancer. For therapies where high activities are administered, the liver can become a dose-limiting organ; often with a complex, non-uniform activity distribution and resulting non-uniform absorbed-dose distribution. This paper therefore presents a small-scale dosimetry model for various source-target combinations within the human liver microarchitecture. Using Monte Carlo simulations, Medical Internal Radiation Dose formalism-compatible specific absorbed fractions were calculated for monoenergetic electrons; photons; alpha particles; and 125I, 90Y, 211At, 99mTc, 111In, 177Lu, 131I and 18F. S values and the ratio of local absorbed dose to the whole-organ average absorbed dose was calculated, enabling a transformation of dosimetry calculations from macro- to microstructure level. For heterogeneous activity distributions, for example uptake in Kupffer cells of radionuclides emitting low-energy electrons (125I) or high-LET alpha particles (211At) the target absorbed dose for the part of the space of Disse, closest to the source, was more than eight- and five-fold the average absorbed dose to the liver, respectively. With the increasing interest in radionuclide therapy of the liver, the presented model is an applicable tool for small-scale liver dosimetry in order to study detailed dose-effect relationships in the liver.

  20. A review of instruments and methods for dosimetry in space

    NASA Astrophysics Data System (ADS)

    Caffrey, Jarvis A.; Hamby, D. M.

    2011-02-01

    Instruments and methods recently used for space radiation dosimetry are reviewed for the purposes of comparison and reference. Passive detection methods mentioned include track-etch, luminescent, nuclear emulsion, and metal foil detectors. These can provide a reliable source of data for all types of radiation, but often require processing that cannot occur in space. Experimental methods of LET determination using TLDs, such as the high temperature peak ratio (HTR) method, are also discussed. Portable readout passive detectors including Pille, MOSFET, and bubble detector systems provide a novel alternative to traditional passive detectors, but research is more limited and their widespread use has yet to be established. Active detectors including DOSTEL, CPDS, RRMD-III, TEPC, R-16, BBND, and the Liulin series are examined for technical details. These instruments allow the determination of dose in real-time, and some can determine LET of incident particles by measuring energy deposition over a known path-length, but size and power consumption limit their practical use for dosimetry. Improved neutron dosimetry and development of a small active or portable readout personnel dosimeter capable of accurate LET determination are important steps for managing the effects of long-term exposure to the space radiation environment.

  1. Effects of water on fingernail electron paramagnetic resonance dosimetry

    PubMed Central

    Zhang, Tengda; Zhao, Zhixin; Zhang, Haiying; Zhai, Hezheng; Ruan, Shuzhou; Jiao, Ling; Zhang, Wenyi

    2016-01-01

    Electron paramagnetic resonance (EPR) is a promising biodosimetric method, and fingernails are sensitive biomaterials to ionizing radiation. Therefore, kinetic energy released per unit mass (kerma) can be estimated by measuring the level of free radicals within fingernails, using EPR. However, to date this dosimetry has been deficient and insufficiently accurate. In the sampling processes and measurements, water plays a significant role. This paper discusses many effects of water on fingernail EPR dosimetry, including disturbance to EPR measurements and two different effects on the production of free radicals. Water that is unable to contact free radicals can promote the production of free radicals due to indirect ionizing effects. Therefore, varying water content within fingernails can lead to varying growth rates in the free radical concentration after irradiation—these two variables have a linear relationship, with a slope of 1.8143. Thus, EPR dosimetry needs to be adjusted according to the water content of the fingernails of an individual. When the free radicals are exposed to water, the eliminating effect will appear. Therefore, soaking fingernail pieces in water before irradiation, as many researchers have previously done, can cause estimation errors. In addition, nails need to be dehydrated before making accurately quantitative EPR measurements. PMID:27342838

  2. The Chernobyl experience in the area of retrospective dosimetry.

    PubMed

    Chumak, Vadim V

    2012-03-01

    The Chernobyl accident, which occurred on 26 April 1986 at a nuclear power plant located less than 150 km north of Kiev, was the largest nuclear accident to date. The unprecedented scale of the accident was determined not only by the amount of released activity, but also by the number of workers and of the general public involved, and therefore exposed to increased doses of ionising radiation. Due to the unexpected and large scale of the accident, dosimetry techniques and practices were far from the optimum; personal dosimetry of cleanup workers (liquidators) was not complete, and there were no direct measurements of the exposures of members of the public. As a result, an acute need for retrospective dose assessment was dictated by radiation protection and research considerations. In response, substantial efforts have been made to reconstruct doses for the main exposed cohorts, using a broad variety of newly developed methods: analytical, biological and physical (electron paramagnetic resonance spectroscopy of teeth, thermoluminescence of quartz) and modelling. This paper reviews the extensive experience gained by the National Research Center for Radiation Medicine, Academy of Medical Sciences, Ukraine in the field of retrospective dosimetry of large cohorts of exposed population and professionals. These dose reconstruction projects were implemented, in particular, in the framework of epidemiological studies, designed to follow-up the medical consequences of the Chernobyl accident and study health effects of ionizing radiation, particularly Ukrainian-American studies of cataracts and leukaemia among liquidators.

  3. Tumor dosimetry in radioimmunotherapy: Methods of calculation for beta particles

    SciTech Connect

    Leichner, P.K. ); Kwok, C.S. )

    1993-03-01

    Calculational methods of beta-particle dosimetry in radioimmunotherapy (RIT) are reviewed for clinical and experimental studies and computer modeling of tumors. In clinical studies, absorbed-dose estimates are usually based on the [ital in]-[ital vivo] quantitation of the activity in tumors from gamma camera images. Because of the limited spatial resolution of gamma cameras, clinical dosimetry is necessarily limited to the macroscopic level (macrodosimetry) and the MIRD formalism for absorbed-dose calculations is appropriate. In experimental RIT, tumor dimensions are often comparable to or smaller than the beta-particle range of commonly used radionuclides (for example, [sup 131]I, [sup 67]Cu, [sup 186]Re, [sup 188]Re, [sup 90]Y) and deviations from the equilibrium dose must be taken into account in absorbed-dose calculations. Additionally, if small tumors are growing rapidly at the time of RIT, the effects of tumor growth will need to be included in absorbed-dose estimates. In computer modeling of absorbed-dose distributions, analytical, numerical, and Monte Carlo methods have been used to investigate the consequences of uniform and nonuniform activity distributions and the effects of inhomogeneous media. Measurements and calculations of the local absorbed dose at the multicellular level have shown that variations in this dose are large. Knowledge of the absorbed dose is essential for any form of radiotherapy. Therefore, it is important that clinical, experimental, and theoretical investigations continue to provide information on tumor dosimetry that is necessary for a better understanding of the radiobiological effects of RIT.

  4. Proceedings of the second conference on radiation protection and dosimetry

    SciTech Connect

    Swaja, R. E.; Sims, C. S.

    1988-11-01

    The Second Conference on Radiation Protection and Dosimetry was held during October 31--November 3, 1988, at the Holiday Inn, Crowne Plaza Hotel in Orlando, Florida. This meeting was designed with the objectives of promoting communication among applied, research, regulatory, and standards personnel involved in radiation protection and providing them with sufficient information to evaluate their programs. To facilitate meeting these objectives, a technical program consisting of more than 75 invited and contributed oral presentations encompassing all aspects of radiation protection was prepared. General topics considered in the technical sessions included external dosimetry, internal dosimetry, calibration, standards and regulations, instrumentation, accreditation and test programs, research advances, and applied program experience. In addition, special sessions were held to afford attendees the opportunity to make short presentations of recent work or to discuss topics of general interest. This document provides a summary of the conference technical program and a partial collection of full papers for the oral presentations in order of delivery. Individual papers were processed separately for the data base.

  5. INTRINSIC DOSIMETRY: A POTENTIAL NEW TOOL FOR NUCLEAR FORENSICS INVESTIGATIONS

    SciTech Connect

    Clark, Richard A.; Miller, Steven D.; Robertson, Dave J.; Gregg, Roger A.; Murphy, Mark K.; Schwantes, Jon M.

    2010-08-11

    Thermoluminescence (TL) dosimetry was used to measure dose effects on the raw stock material of borosilicate container glass from different geographical locations. Effects were studied at times up to 60 days post-irradiation at doses from 0.15 to 20 Gy. The minimum detectable dose using this technique was estimated to be 0.15 Gy which is roughly equivalent to a 24 hr irradiation 1 cm from a 50 ng source of 60Co. Two peaks were identified in the TL glow curve, a relatively unstable peak around 125°C and a more stable peak around 225°C. Differences in TL glow curve shape and intensity were also observed for the glasses from different geographical origins. We investigate radiation induced defects in glass to further develop the technique of intrinsic dosimetry–the measurement of the total absorbed dose received by the walls of a container holding radioactive material. Intrinsic dosimetry is intended to be used as an interrogation tool to provide enhanced pathway information on interdicted or newly discovered waste containers of unknown origin or history by considering the total absorbed dose received by a container in tandem with the physical characteristics of the radioactive material housed within that container. One hypothetical scenario is presented to illustrate the application of intrinsic dosimetry to waste management and nuclear forensics.

  6. On the reliability of 3D gel dosimetry

    NASA Astrophysics Data System (ADS)

    De Deene, Y.; Vandecasteele, J.

    2013-06-01

    Gel dosimetry has a unique role to play in safeguarding conformal radiotherapy treatments as it covers the whole treatment chain and provides the radiation oncologist with the integrated dose distribution in 3D. A major obstacle that has hindered the wider dissemination of polymer gel dosimetry in radiotherapy centres is the lack of confidence in the reliability of the measured dose. Discrepancies in dose response of small versus large polymer gel dosimeters have been reported and although several hypothesis for these discrepancies have been postulated, the actual contribution of these error sources to the overall inaccuracy of the dose maps has not been determined. Several gel dosimetry research groups have chosen to use an internal calibration of gel dosimeters. In this study, the inter-and intra-batch reproducibility of the current state-of-the-art 3D gel dosimeters has been assessed. It is demonstrated that with a carefully designed scanning set-up, the overall accuracy that can be obtained with an independent calibration is well within 5% of all pixels.

  7. A small-scale anatomical dosimetry model of the liver.

    PubMed

    Stenvall, Anna; Larsson, Erik; Strand, Sven-Erik; Jönsson, Bo-Anders

    2014-07-07

    Radionuclide therapy is a growing and promising approach for treating and prolonging the lives of patients with cancer. For therapies where high activities are administered, the liver can become a dose-limiting organ; often with a complex, non-uniform activity distribution and resulting non-uniform absorbed-dose distribution. This paper therefore presents a small-scale dosimetry model for various source-target combinations within the human liver microarchitecture. Using Monte Carlo simulations, Medical Internal Radiation Dose formalism-compatible specific absorbed fractions were calculated for monoenergetic electrons; photons; alpha particles; and (125)I, (90)Y, (211)At, (99m)Tc, (111)In, (177)Lu, (131)I and (18)F. S values and the ratio of local absorbed dose to the whole-organ average absorbed dose was calculated, enabling a transformation of dosimetry calculations from macro- to microstructure level. For heterogeneous activity distributions, for example uptake in Kupffer cells of radionuclides emitting low-energy electrons ((125)I) or high-LET alpha particles ((211)At) the target absorbed dose for the part of the space of Disse, closest to the source, was more than eight- and five-fold the average absorbed dose to the liver, respectively. With the increasing interest in radionuclide therapy of the liver, the presented model is an applicable tool for small-scale liver dosimetry in order to study detailed dose-effect relationships in the liver.

  8. Real-time dosimetry in radiotherapy using tailored optical fibers

    NASA Astrophysics Data System (ADS)

    Rahman, A. K. M. Mizanur; Zubair, H. T.; Begum, Mahfuza; Abdul-Rashid, H. A.; Yusoff, Z.; Omar, Nasr Y. M.; Ung, N. M.; Mat-Sharif, K. A.; Bradley, D. A.

    2016-05-01

    Real-time dosimetry plays an important role for accurate patient-dose measurement during radiotherapy. A tiny piece of laboratory fabricated Ge-doped optical fiber has been investigated as a radioluminescence (RL) sensor for real-time dosimetry over the dose range from 1 Gy to 8 Gy under 6 MV photon beam by LINAC. Fiber-coupled software-based RL prototype system was used to assess essential dosimetric characteristics including dose response linearity, dose rate dependency, sensitivity, repeatability and output dependence on field sizes. The consistency level of RL photon counts versus dose rate was also compared with that of standard Al2O3:C chips. Sensitivity of Ge-doped fiber were found to be sufficiently sensitive for practical use and also provided linear dose responses for various dose rates from 100 cGy/min to 600 cGy/min using both 6 MV photon and 6 MeV electron beams. SEM-EDX analysis was performed to identify Ge-dopant concentration level within the optical fiber RL material. Accumulated doses were also estimated using simple integral technique and the error was found to be around less than 1% under dissimilar dose rates or repeat measurements. The evaluation of the Ge-doped optical fiber based RL dosimeter system indicates its potential in medical dosimetry.

  9. Cobb's Red Cabbage Indicator.

    ERIC Educational Resources Information Center

    Cobb, Vicki

    1998-01-01

    Describes the use of an indicator made from the pigment in red cabbage. Cabbage is grated then soaked in water. When the water is a strong red, the cabbage is strained out. The cabbage-juice indicator is then used to test for acids and bases. Includes a list of good foods to test for acidity and alkalinity. (PVD)

  10. A Fatal Case of Immune Hyperhemolysis with Bone Marrow Necrosis in a Patient with Sickle Cell Disease

    PubMed Central

    Singavi, Arun; Johnson, Susan T.; Field, Joshua J.

    2017-01-01

    In patients with sickle cell disease, hyperhemolysis is a rare but life-threatening complication of transfusion. In this case report, we describe a 61 year-old woman with hemoglobin sickle cell (SC) disease and history of alloimmunization who developed hyperhemolysis associated with a transfusion. She was found to have a warm and a clinically-significant cold autoantibody. Severe anemia (Hb 2.7 g/dL) with reticulocytopenia and thrombocytopenia prompted a bone marrow biopsy, which demonstrated extensive bone marrow necrosis. Despite treatment, the bone marrow failure did not improve and the patient died on hospital day 38. This case illustrates the potential risks of transfusion in a patient with sickle cell disease, especially one with previous hemolytic reactions. While uncommon, hyperhemolysis can cause death, in this case by extensive bone marrow necrosis. In patients with sickle cell disease, judicious use of red cell transfusions with phenotypically-matched units can diminish, but never completely abrogate, the risks associated with transfusion. PMID:28286630

  11. Reference dosimetry measurements for the international intercomparison of criticality accident dosimetry SILENE 9-21 June 2002.

    PubMed

    Asselineau, B; Trompier, F; Texier, C; Itié, C; Médioni, R; Tikunov, D; Muller, H; Pelcot, G

    2004-01-01

    An international intercomparison of criticality accident dosimetry systems took place in the SILENE reactor, in June 2002. Participants from 60 laboratories irradiated their dosemeters (physical and biological) using two different configurations of the reactor. In preparation for this intercomparison, the leakage radiation fields were characterised by spectrometry and dosimetry measurements using the ROSPEC spectrometer associated with a NE-213 scintillator, ionisation chambers, GM counters, diodes and thermoluminescence dosemeters (TLDs). For this intercomparison, a large area was required to irradiate the dosemeters both in free air and on phantoms. Therefore, measurements of the uniformity of the field were performed with activation detectors and TLDs for neutron and gammas, respectively. This paper describes the procedures used and the results obtained.

  12. Bone Marrow Edema: Chronic Bone Marrow Lesions of the Knee and the Association with Osteoarthritis.

    PubMed

    Collins, Jason A; Beutel, Bryan G; Strauss, Eric; Youm, Thomas; Jazrawi, Laith

    2016-03-01

    Bone marrow edema of the knee occurs secondary to a myriad of causes. The hallmark of a bone marrow lesion (BML) is an area of decreased signal intensity on T1 weighted MRI with a corresponding area of increased signal intensity on a T2 weighted MRI. Recently, chronic bone marrow lesions have been correlated with knee pain and progression of osteoarthritis. These lesions have also been associated with other degenerative conditions such as meniscal tears, cartilage deterioration, subchondral cyst formation, mechanical malalignment, and ultimately progression to arthroplasty. Medical treatments, such as prostacyclin and bisphosphonate therapy, have shown promise. Alignment procedures, as well as core decompression and subchondroplasty, have been used as surgical treatments for chronic BMLs.

  13. Quasi 3D dosimetry (EPID, conventional 2D/3D detector matrices)

    NASA Astrophysics Data System (ADS)

    Bäck, A.

    2015-01-01

    Patient specific pretreatment measurement for IMRT and VMAT QA should preferably give information with a high resolution in 3D. The ability to distinguish complex treatment plans, i.e. treatment plans with a difference between measured and calculated dose distributions that exceeds a specified tolerance, puts high demands on the dosimetry system used for the pretreatment measurements and the results of the measurement evaluation needs a clinical interpretation. There are a number of commercial dosimetry systems designed for pretreatment IMRT QA measurements. 2D arrays such as MapCHECK® (Sun Nuclear), MatriXXEvolution (IBA Dosimetry) and OCTAVIOUS® 1500 (PTW), 3D phantoms such as OCTAVIUS® 4D (PTW), ArcCHECK® (Sun Nuclear) and Delta4 (ScandiDos) and software for EPID dosimetry and 3D reconstruction of the dose in the patient geometry such as EPIDoseTM (Sun Nuclear) and Dosimetry CheckTM (Math Resolutions) are available. None of those dosimetry systems can measure the 3D dose distribution with a high resolution (full 3D dose distribution). Those systems can be called quasi 3D dosimetry systems. To be able to estimate the delivered dose in full 3D the user is dependent on a calculation algorithm in the software of the dosimetry system. All the vendors of the dosimetry systems mentioned above provide calculation algorithms to reconstruct a full 3D dose in the patient geometry. This enables analyzes of the difference between measured and calculated dose distributions in DVHs of the structures of clinical interest which facilitates the clinical interpretation and is a promising tool to be used for pretreatment IMRT QA measurements. However, independent validation studies on the accuracy of those algorithms are scarce. Pretreatment IMRT QA using the quasi 3D dosimetry systems mentioned above rely on both measurement uncertainty and accuracy of calculation algorithms. In this article, these quasi 3D dosimetry systems and their use in patient specific pretreatment IMRT

  14. Studies on Red Cell Aplasia. V. PRESENCE OF ERYTHROBLAST CYTOTOXICITY IN γG-GLOBULIN FRACTION OF PLASMA

    PubMed Central

    Krantz, Sanford B.; Moore, W. H.; Zaentz, S. Donald

    1973-01-01

    The marrow cells of a patient with pure red cell aplasia markedly increased their rate of heme synthesis when they were freed from the host environment and were incubated in vitro. When the red cell aplasia was treated with cyclophosphamide and prednisone, marrow cell incorporation of 59Fe into heme in vitro increased several weeks before a reticulocytosis was apparent, and was the earliest effect noted. The plasma γG-globulins of this patient inhibited heme synthesis by normal marrow cells or the patient's own marrow cells obtained after remission of the disease. Since the inhibition of heme synthesis could be the result of damage to erythroblasts, the patient's posttreatment marrow cells or normal marrow cells were labeled with 59Fe and were then incubated with the patient's pretreatment, treatment, and posttreatment γG-globulins as well as normal γG-globulins. At the end of this incubation the supernatant and cells were separated and counted. Heme was extracted and also was counted. Treatment of the cells with the patient's pretreatment γG-globulins resulted in a release of 40% of the radioactive heme from the cells. This represented the loss of radioactive hemoglobin and was an index of erythroblast cytotoxicity. A progressive disappearance of the cytotoxic factor in the γG-globulins occurred in the 3 wk period preceding the onset of reticulocytes in the patient's blood. Posttreatment and normal γG-globulins did not produce this effect and increased injury of red cells and lymphocytes was not produced by the patient's pretreatment γG-globulins. These studies demonstrate a method for measuring erythroblast cytoxicity and show that red cell aplasia is associated with γG-globulins that specifically damage erythroblasts. Whether interference with new erythroblast development also occurs and contributes to the inhibition of heme synthesis has not yet been ascertained. Images PMID:4119161

  15. Updating and extending the IRDF-2002 dosimetry library

    SciTech Connect

    Capote, R.; Zolotarev, K.I.; Pronyaev, V.G.; Trkov, A.

    2011-07-01

    The International Reactor Dosimetry File (IRDF)-2002 released in 2004 by the IAEA (see http://www-nds.iaea.org/irdf2002/) contains cross-section data and corresponding uncertainties for 66 dosimetry reactions. New cross-section evaluations have become available recently that re-define some of these dosimetry reactions including: (1) high-fidelity evaluation work undertaken by one of the authors (KIZ); (2) evaluations from the US ENDF/B-VII.0 and candidate evaluations from the US ENDF/B-VII.1 libraries that cover reactions within the International Evaluation of Neutron Cross-Section Standards; (3) European JEFF3.1 library; and (4) Japanese JENDL-4.0 library. Additional high-threshold reactions not included in IRDF-2002 (e.g., {sup 59C}o(n,3n) and {sup 209}Bi(n,3n)) have been also evaluated to characterize higher-energy neutron fields. Overall, 37 new evaluations of dosimetry reactions have been assessed and intercomparisons made with integral measurements in reference neutron fields to determine whether they should be adopted to update and improve IRDF-2002. Benchmark calculations performed for newly evaluated reactions using the ENDF/B-VII.0 {sup 235}U thermal fission and {sup 252}Cf spontaneous fission neutron spectra show that calculated integral cross sections exhibit improved agreement with evaluated experimental data when compared with the equivalent data from the IRDF-2002 library. Data inconsistencies or deficiencies of new evaluations have been identified for {sup 63}Cu(n,2n), {sup 60}Ni(n,p) {sup 60m+g}Co, {sup 55}Mn(n,{gamma}), and {sup 232}Th(n,f) reactions. Compared with IRDF-2002, the upper neutron energy boundary was formally increased from the actual maximum energy of typically 20 MeV up to 60 MeV by using the TENDL-2010 cross sections and covariance matrices. This extension would allow the updated IRDF library to be also used in fusion dosimetry applications. Uncertainties in the cross sections for all new evaluations are given in the form of

  16. Air kerma based dosimetry calibration for the Leksell Gamma Knife

    SciTech Connect

    Meltsner, Sheridan Griffin; DeWerd, Larry A.

    2009-02-15

    No accepted official protocol exists for the dosimetry of the Leksell Gamma Knife registered (GK) stereotactic radiosurgery device. Establishment of a dosimetry protocol has been complicated by the unique partial-hemisphere arrangement of 201 individual {sup 60}Co beams simultaneously focused on the treatment volume and by the rigid geometry of the GK unit itself. This article proposes an air kerma based dosimetry protocol using either an in-air or in-acrylic phantom measurement to determine the absorbed dose rate of fields of the 18 mm helmet of a GK unit. A small-volume air ionization chamber was used to make measurements at the physical isocenter of three GK units. The absorbed dose rate to water was determined using a modified version of the AAPM Task Group 21 protocol designed for use with {sup 60}Co-based teletherapy machines. This experimentally determined absorbed dose rate was compared to the treatment planning system (TPS) absorbed dose rate. The TPS used with the GK unit is Leksell GammaPlan. The TPS absorbed dose rate at the time of treatment is the absorbed dose rate determined by the physicist at the time of machine commissioning decay corrected to the treatment date. The TPS absorbed dose rate is defined as absorbed dose rate to water at the isocenter of a water phantom with a radius of 8 cm. Measurements were performed on model B and C Gamma Knife units. The absorbed dose rate to water for the 18 mm helmet determined using air-kerma based calculations is consistently between 1.5% and 2.9% higher than the absorbed dose rate provided by the TPS. These air kerma based measurements allow GK dosimetry to be performed with an established dosimetry protocol and without complications arising from the use of and possible variations in solid phantom material. Measurements were also made with the same ionization chamber in a spherical acrylic phantom for comparison. This methodology will allow further development of calibration methods appropriate for the

  17. Pure red cell aplasia induced by epoetin zeta

    PubMed Central

    Panichi, Vincenzo; Ricchiuti, Guido; Scatena, Alessia; Del Vecchio, Lucia; Locatelli, Francesco

    2016-01-01

    Pure red cell aplasia (PRCA) may develop in patients with chronic kidney disease receiving erythropoiesis-stimulating agents (ESA). We report on a 72-year-old patient who developed hypo-proliferative anaemia unresponsive to ESA following the administration of epoetin zeta subcutaneously for 7 months. On the basis of severe isolated hypoplasia of the erythroid line in the bone marrow and high-titre neutralizing anti-erythropoietin antibodies (Ab), a diagnosis of Ab-mediated PRCA was made. Epoetin zeta was discontinued and the patient was given steroids. This was associated with anaemia recovery. To our knowledge this is the first PRCA case related to epoetin zeta. PMID:27478604

  18. An international dosimetry exchange for BNCT part II: computational dosimetry normalizations.

    PubMed

    Riley, K J; Binns, P J; Harling, O K; Albritton, J R; Kiger, W S; Rezaei, A; Sköld, K; Seppälä, T; Savolainen, S; Auterinen, I; Marek, M; Viererbl, L; Nievaart, V A; Moss, R L

    2008-12-01

    The meaningful sharing and combining of clinical results from different centers in the world performing boron neutron capture therapy (BNCT) requires improved precision in dose specification between programs. To this end absorbed dose normalizations were performed for the European clinical centers at the Joint Research Centre of the European Commission, Petten (The Netherlands), Nuclear Research Institute, Rez (Czech Republic), VTT, Espoo (Finland), and Studsvik, Nyköping (Sweden). Each European group prepared a treatment plan calculation that was bench-marked against Massachusetts Institute of Technology (MIT) dosimetry performed in a large, water-filled phantom to uniformly evaluate dose specifications with an estimated precision of +/-2%-3%. These normalizations were compared with those derived from an earlier exchange between Brookhaven National Laboratory (BNL) and MIT in the USA. Neglecting the uncertainties related to biological weighting factors, large variations between calculated and measured dose are apparent that depend upon the 10B uptake in tissue. Assuming a boron concentration of 15 microg g(-1) in normal tissue, differences in the evaluated maximum dose to brain for the same nominal specification of 10 Gy(w) at the different facilities range between 7.6 and 13.2 Gy(w) in the trials using boronophenylalanine (BPA) as the boron delivery compound and between 8.9 and 11.1 Gy(w) in the two boron sulfhydryl (BSH) studies. Most notably, the value for the same specified dose of 10 Gy(w) determined at the different participating centers using BPA is significantly higher than at BNL by 32% (MIT), 43% (VTT), 49% (JRC), and 74% (Studsvik). Conversion of dose specification is now possible between all active participants and should be incorporated into future multi-center patient analyses.

  19. Bone marrow transfusions in previously irradiated, hematologically normal syngeneic mice

    SciTech Connect

    Brecher, G.; Lawce, H.; Tjio, J.H.

    1981-03-01

    Transfusion of syngeneic marrow into normal, nonirradiated recipients results only in minimal proliferation of donor cells. However, irradiated recipients, restored to hematologic normalcy by an initial marrow transfusion, subsequently sustain proliferation which replaces approximately 10% of endogenous marrow after a single transfusion of 4 x 10/sup 7/ marrow cells of the same strain as the host. Cells from histoincompatible donors proliferate only rarely or minimally in the marrows of these irradiated, but hematologically normal recipients without reirradiation. Syngeneic male donor cells proliferate in irradiated and restored female mice, while female donor cells fail to proliferate in the marrow of syngeneic male recipients. A possible explanation is that transfused female cells respond immunologically to the abundant H-Y antigen in the male environment and are eliminated as a result.

  20. Pathophysiological role of enhanced bone marrow adipogenesis in diabetic complications

    PubMed Central

    Piccinin, Meghan A; Khan, Zia A

    2014-01-01

    Diabetes leads to complications in select organ systems primarily by disrupting the vasculature of the target organs. These complications include both micro- (cardiomyopathy, retinopathy, nephropathy, and neuropathy) and macro-(atherosclerosis) angiopathies. Bone marrow angiopathy is also evident in both experimental models of the disease as well as in human diabetes. In addition to vascular disruption, bone loss and increased marrow adiposity have become hallmarks of the diabetic bone phenotype. Emerging evidence now implicates enhanced marrow adipogenesis and changes to cellular makeup of the marrow in a novel mechanistic link between various secondary complications of diabetes. In this review, we explore the mechanisms of enhanced marrow adipogenesis in diabetes and the link between changes to marrow cellular composition, and disruption and depletion of reparative stem cells. PMID:26317050

  1. High Red Blood Cell Count

    MedlinePlus

    Symptoms High red blood cell count By Mayo Clinic Staff A high red blood cell count is an increase in oxygen-carrying cells in your bloodstream. Red blood cells transport oxygen from your lungs to tissues throughout ...

  2. WE-EF-207-05: Monte Carlo Dosimetry for a Dedicated Cone-Beam CT Head Scanner

    SciTech Connect

    Sisniega, A; Zbijewski, W; Xu, J; Dang, H; Stayman, J W; Aygun, N; Koliatsos, V E; Siewerdsen, J H; Wang, X; Foos, D H

    2015-06-15

    Purpose: Cone-Beam CT (CBCT) is an attractive platform for point-of-care imaging of traumatic brain injury and intracranial hemorrhage. This work implements and evaluates a fast Monte-Carlo (MC) dose estimation engine for development of a dedicated head CBCT scanner, optimization of acquisition protocols, geometry, bowtie filter designs, and patient-specific dosimetry. Methods: Dose scoring with a GPU-based MC CBCT simulator was validated on an imaging bench using a modified 16 cm CTDI phantom with 7 ion chamber shafts along the central ray for 80–100 kVp (+2 mm Al, +0.2 mm Cu). Dose distributions were computed in a segmented CBCT reconstruction of an anthropomorphic head phantom with 4×10{sup 5} tracked photons per scan (5 min runtime). Circular orbits with angular span ranging from short scan (180° + fan angle) to full rotation (360°) were considered for fixed total mAs per scan. Two aluminum filters were investigated: aggressive bowtie, and moderate bowtie (matched to 16 cm and 32 cm water cylinder, respectively). Results: MC dose estimates showed strong agreement with measurements (RMSE<0.001 mGy/mAs). A moderate (aggressive) bowtie reduced the dose, per total mAs, by 20% (30%) at the center of the head, by 40% (50%) at the eye lens, and by 70% (80%) at the posterior skin entrance. For the no bowtie configuration, a short scan reduced the eye lens dose by 62% (from 0.08 mGy/mAs to 0.03 mGy/mAs) compared to full scan, although the dose to spinal bone marrow increased by 40%. For both bowties, the short scan resulted in a similar 40% increase in bone marrow dose, but the reduction in the eye lens was more pronounced: 70% (90%) for the moderate (aggressive) bowtie. Conclusions: Dose maps obtained with validated MC simulation demonstrated dose reduction in sensitive structures (eye lens and bone marrow) through combination of short-scan trajectories and bowtie filters. Xiaohui Wang and David Foos are employees of Carestream Health.

  3. A multiscale model of the bone marrow and hematopoiesis

    PubMed Central

    Silva, Ariosto S; Anderson, Alexander R.A.

    2013-01-01

    The bone marrow is necessary for renewal of all hematopoietic cells and critical for maintenance of a wide range of physiologic functions. Multiple human diseases result from bone marrow dysfunction. It is also the site in which “liquid” tumors, including leukemia and multiple myeloma, develop as well as a frequent site of metastases. Understanding the complex cellular and microenvironmental interactions that govern normal bone marrow function as well as diseases and cancers of the bone marrow would be a valuable medical advance. Our goal is the development of a spatially-explicit in silico model of the bone marrow to understand both its normal function and the evolutionary dynamics that govern the emergence of bone marrow malignancy. Here we introduce a multiscale computational model of the bone marrow that incorporates three distinct spatial scales, cell, hematopoietic subunit, whole marrow. Implemented as a fixed lattice 3D cellular automaton, it reproduces the spatial characteristics of the normal bone marrow and is validated against data from the daily production of mature blood cells and response of hematopoiesis after irradiation. The major mechanisms modeled in this work are: (1) replication, specialization and migration of hematopoietic cells, (2) optimized spatial configuration of sinuses and hematopoietic compartments and, (3) intravasation of mature hematopoietic cells into sinuses. Our results, using parameter estimates from literature, recapitulates normal bone marrow function and suggest an explanation for the fractal-like structure of trabeculae and sinuses in the marrow, which would be an optimization of the hematopoietic function in order to maximize the number of mature blood cells produced daily within the volumetric restrictions of the marrow. PMID:21631151

  4. Vertebral hyperemia associated with bone marrow insult and recovery

    SciTech Connect

    Klein, H.A.; Bolden, R.O.; Simone, F.J.

    1984-06-01

    A 15-year-old boy with rhabdoid sarcoma received chemotherapy, which was followed by bone marrow depression, massive nosebleeds and, finally, hematologic recovery. On both hepatobiliary and renal scintigraphy, prominent vertebral activity was present in early images. Correlation with his clinical course suggests that the findings reflect hyperemia due to marrow insult and recovery. Radionuclide imaging to detect hyperemia may be a useful probe for drug effects on hematopoietic bone marrow.

  5. Develop real-time dosimetry concepts and instrumentation for long term missions

    NASA Technical Reports Server (NTRS)

    Braby, L. A.

    1981-01-01

    The development of a rugged portable dosimetry system, based on microdosimetry techniques, which will measure dose and evaluate dose equivalent in a mixed radiation field is described. Progress in the desired dosimetry system can be divided into three distinct areas: development of the radiation detector, and electron system are presented. The mathematical techniques required are investigated.

  6. Dosimetry and quantitative radionuclide imaging in radioimmunotherapy: Final report, July 15, 1992-July 14, 1996

    SciTech Connect

    Leichner, P.K.

    1996-09-01

    Brief summaries of the principal accomplishments of this project on the development of quantitative SPECT for high energy photons (87Y, 19F) and stability testing of 87Y-labeled antibodies in the nude mouse model, development of an unified approach to photon and beta particle dosimetry, quantitative SPECT for nonuniform attenuation, and development of patient-specific dosimetry in radioimmunotherapy.

  7. Relationship between student selection criteria and learner success for medical dosimetry students.

    PubMed

    Baker, Jamie; Tucker, Debra; Raynes, Edilberto; Aitken, Florence; Allen, Pamela

    2016-01-01

    Medical dosimetry education occupies a specialized branch of allied health higher education. Noted international shortages of health care workers, reduced university funding, limitations on faculty staffing, trends in learner attrition, and increased enrollment of nontraditional students force medical dosimetry educational leadership to reevaluate current admission practices. Program officials wish to select medical dosimetry students with the best chances of successful graduation. The purpose of the quantitative ex post facto correlation study was to investigate the relationship between applicant characteristics (cumulative undergraduate grade point average (GPA), science grade point average (SGPA), prior experience as a radiation therapist, and previous academic degrees) and the successful completion of a medical dosimetry program, as measured by graduation. A key finding from the quantitative study was the statistically significant positive correlation between a student׳s previous degree and his or her successful graduation from the medical dosimetry program. Future research investigations could include a larger research sample, representative of more medical dosimetry student populations, and additional studies concerning the relationship of previous work as a radiation therapist and the effect on success as a medical dosimetry student. Based on the quantitative correlation analysis, medical dosimetry leadership on admissions committees could revise student selection rubrics to place less emphasis on an applicant׳s undergraduate cumulative GPA and increase the weight assigned to previous degrees.

  8. Dosimetry in 131I-mIBG therapy: moving toward personalized medicine.

    PubMed

    Chiesa, C; Castellani, R; Mira, M; Lorenzoni, A; Flux, G D

    2013-06-01

    Internal dosimetry was developed as a basis for 131I-mIBG treatment at an early stage and has continued to develop for over the last 20 years. Whole-body dosimetry was introduced to prevent hematological toxicity. It will be the basis for a forthcoming European multicentre trial, in which the activity of a second administration is determined according to the results calculated from the first. Lesion dosimetry has also been performed in a small number of centres. The major goal of dosimetry now is to establish dose-effect correlation studies, which will be the basis for individualized treatment planning. The aim of this paper is to analyse previously published studies and to consider the potential for improvement in order to obtain a stronger predictive power of dosimetry. The intrinsic radiobiological limits of dosimetry are also illustrated. Due to the development and dissemination of methods of internal dosimetry and radiobiology over the last two decades, and to the increasing availability of quantitative 124I PET imaging, dosimetry could provide in the near future a more systematic basis for standardization and individualization of mIBG therapy. This will however require a number of multicentre trials which are performed under good instrumental and scientific methodology.

  9. Methods and Models of the Hanford Internal Dosimetry Program, PNNL-MA-860

    SciTech Connect

    Carbaugh, Eugene H.; Bihl, Donald E.; Maclellan, Jay A.

    2003-01-03

    This manual describes the technical basis for the design of the routine radiobioassay monitoring program and assessments of internal dose. Its purpose is to provide a historical record of the methods, models, and assumptions used for internal dosimetry at Hanford, and serve as a technical reference for radiation protection and dosimetry staff.

  10. Relationship between student selection criteria and learner success for medical dosimetry students

    SciTech Connect

    Baker, Jamie; Tucker, Debra; Raynes, Edilberto; Aitken, Florence; Allen, Pamela

    2016-04-01

    Medical dosimetry education occupies a specialized branch of allied health higher education. Noted international shortages of health care workers, reduced university funding, limitations on faculty staffing, trends in learner attrition, and increased enrollment of nontraditional students force medical dosimetry educational leadership to reevaluate current admission practices. Program officials wish to select medical dosimetry students with the best chances of successful graduation. The purpose of the quantitative ex post facto correlation study was to investigate the relationship between applicant characteristics (cumulative undergraduate grade point average (GPA), science grade point average (SGPA), prior experience as a radiation therapist, and previous academic degrees) and the successful completion of a medical dosimetry program, as measured by graduation. A key finding from the quantitative study was the statistically significant positive correlation between a student's previous degree and his or her successful graduation from the medical dosimetry program. Future research investigations could include a larger research sample, representative of more medical dosimetry student populations, and additional studies concerning the relationship of previous work as a radiation therapist and the effect on success as a medical dosimetry student. Based on the quantitative correlation analysis, medical dosimetry leadership on admissions committees could revise student selection rubrics to place less emphasis on an applicant's undergraduate cumulative GPA and increase the weight assigned to previous degrees.

  11. Japanese epidemiological survey with consensus statement on Japanese guidelines for treatment of iron overload in bone marrow failure syndromes

    PubMed Central

    Suzuki, Takahiro; Tomonaga, Masao; Miyazaki, Yasushi; Nakao, Shinji; Ohyashiki, Kazuma; Matsumura, Itaru; Kohgo, Yutaka; Niitsu, Yoshiro; Kojima, Seiji

    2008-01-01

    Many patients with bone marrow failure syndromes need frequent transfusions of red blood cells, and most of them eventually suffer from organ dysfunction induced by excessively accumulated iron. The only way to treat transfusion-induced iron overload is iron chelating therapy. However, most patients have not been treated effectively because daily/continuous administration of deferoxamine is difficult for outpatients. Recently, a novel oral iron chelator, deferasirox, has been developed, and introduction of the drug may help many patients benefit from iron chelation therapy. In this review, we will discuss the current status of iron overload in transfusion-dependent patients, and the development of Japanese guidelines for the treatment of iron overload in Japan, which were established by the National Research Group on Idiopathic Bone Marrow Failure Syndromes in Japan. PMID:18581199

  12. Comparison of Different Internal Dosimetry Systems for Selected Radionuclides Important to Nuclear Power Production

    SciTech Connect

    Leggett, Richard Wayne; Eckerman, Keith F; Manger, Ryan P

    2013-08-01

    This report compares three different radiation dosimetry systems currently applied by various U.S. Federal agencies and dose estimates based on these three dosimetry systems for a set of radionuclides often identified in power reactor effluents. These dosimetry systems were developed and applied by the International Commission on Radiological Protection at different times over the past six decades. Two primary modes of intake of radionuclides are addressed: ingestion in drinking water and inhalation. Estimated doses to individual organs and to the whole body based on each dosimetry system are compared for each of four age groups: infant, child, teenager, and adult. Substantial differences between dosimetry systems in estimated dose per unit intake are found for some individual radionuclides, but differences in estimated dose per unit intake generally are modest for mixtures of radionuclides typically found in nuclear power plant effluents.

  13. Radiation Dosimetry via Automated Fluorescence Microscopy

    NASA Technical Reports Server (NTRS)

    Castleman, Kenneth R.; Schulze, Mark

    2005-01-01

    A developmental instrument for assessment of radiation-induced damage in human lymphocytes includes an automated fluorescence microscope equipped with a one or more chargecoupled- device (CCD) video camera(s) and circuitry to digitize the video output. The microscope is also equipped with a three-axis translation stage that includes a rotation stage, and a rotary tray that holds as many as thirty specimen slides. The figure depicts one version of the instrument. Once the slides have been prepared and loaded into the tray, the instrument can operate unattended. A computer controls the operation of the stage, tray, and microscope, and processes the digital fluorescence-image data to recognize and count chromosomes that have been broken, presumably by radiation. The design and method of operation of the instrument exploit fluorescence in situ hybridization (FISH) of metaphase chromosome spreads, which is a technique that has been found to be valuable for monitoring the radiation dose to circulating lymphocytes. In the specific FISH protocol used to prepare specimens for this instrument, metaphase lymphocyte cultures are chosen for high mitotic index and highly condensed chromosomes, then several of the largest chromosomes are labeled with three of four differently colored whole-chromosome-staining dyes. The three dyes, which are used both individually and in various combinations, are fluorescein isothiocyanate (FITC), Texas Red (or equivalent), and Cy5 (or equivalent); The fourth dye 4',6-diamidino- 2-phenylindole (DAPI) is used as a counterstain. Under control by the computer, the microscope is automatically focused on the cells and each slide is scanned while the computer analyzes the DAPI-fluorescence images to find the metaphases. Each metaphase field is recentered in the field of view and refocused. Then a four-color image (more precisely, a set of images of the same view in the fluorescent colors of the four dyes) is acquired. By use of pattern

  14. Effects of mixed hematopoietic chimerism in a mouse model of bone marrow transplantation for sickle cell anemia.

    PubMed

    Iannone, R; Luznik, L; Engstrom, L W; Tennessee, S L; Askin, F B; Casella, J F; Kickler, T S; Goodman, S N; Hawkins, A L; Griffin, C A; Noffsinger, L; Fuchs, E J

    2001-06-15

    Sickle cell anemia (SCA) is an inherited disorder of beta-globin, resulting in red blood cell rigidity, anemia, painful crises, organ infarctions, and reduced life expectancy. Allogeneic blood or marrow transplantation (BMT) can cure SCA but is associated with an 8% to 10% mortality rate, primarily from complications of marrow-ablative conditioning. Transplantation of allogeneic marrow after less intensive conditioning reduces toxicity but may result in stable mixed hematopoietic chimerism. The few SCA patients who inadvertently developed mixed chimerism after BMT remain symptom free, suggesting that mixed chimerism can reduce disease-related morbidity. However, because the effects of various levels of mixed chimerism on organ pathology have not been characterized, this study examined the histologic effects of an increasing percentage of normal donor hematopoiesis in a mouse model of BMT for SCA. In lethally irradiated normal mice that were reconstituted with varying ratios of T-cell-depleted marrow from normal and transgenic "sickle cell" mice, normal myeloid chimerism in excess of 25% was associated with more than 90% normal hemoglobin (Hb). However, 70% normal myeloid chimerism was required to reverse the anemia. Organ pathology, including liver infarction, was present in mice with sickle Hb (HbS) levels as low as 16.8% (19.6% normal myeloid chimerism). Histologic abnormalities increased in severity up to 80% HbS, but were less severe in mice with more than 80% HbS than in those with 40% to 80% HbS. Therefore, stable mixed chimerism resulting from nonmyeloablative BMT may reduce the morbidity from SCA, but prevention of all disease complications may require minimizing the fraction of circulating sickle red cells. (Blood. 2001;97:3960-3965)

  15. Red Bull Stratos Presentation

    NASA Video Gallery

    Red Bull Stratos High Performance Director Andy Walshe & Technical Project Director Art Thompson share the Stratos story with JSC. Supported by a team of experts, Felix Baumgartner reached 128,100 ...

  16. Red Hill Updates

    EPA Pesticide Factsheets

    This and other periodic updates are intended to keep the public informed on major progress being made to protect public health and the environment at the Red Hill Underground Fuel Storage Facility in Hawaii.

  17. Bone marrow and bone marrow derived mononuclear stem cells therapy for the chronically ischemic myocardium

    SciTech Connect

    Waksman, Ron; Baffour, Richard

    2003-09-01

    Bone marrow stem cells have been shown to differentiate into various phenotypes including cardiomyocytes, vascular endothelial cells and smooth muscle. Bone marrow stem cells are mobilized and home in to areas of injured myocardium where they are involved in tissue repair. In addition, bone marrow secretes multiple growth factors, which are essential for angiogenesis and arteriogenesis. In some patients, these processes are not enough to avert clinical symptoms of ischemic disease. Therefore, in vivo administration of an adequate number of stem cells would be a significant therapeutic advance. Unfractionated bone marrow derived mononuclear stem cells, which contain both hematopoietic and nonhematopoietic cells may be more appropriate for cell therapy. Studies in animal models suggest that implantation of different types of stem cells improve angiogenesis and arteriogenesis, tissue perfusion as well as left ventricular function. Several unanswered questions remain. For example, the optimal delivery approach, dosage and timing of the administration of cell therapy as well as durability of improvements need to be studied. Early clinical studies have demonstrated safety and feasibility of various cell therapies in ischemic disease. Randomized, double blind and placebo-controlled clinical trials need to be completed to determine the effectiveness of stem cell.

  18. Bone marrow-derived dendritic cells.

    PubMed

    Roney, Kelly

    2013-01-01

    While much is understood about dendritic cells and their role in the immune system, the study of these cells is critical to gain a more complete understanding of their function. Dendritic cell isolation from mouse body tissues can be difficult and the number of cells isolated small. This protocol describes the growth of large number of dendritic cells from the culture of mouse bone marrow cells. The dendritic cells grown in culture facilitate experiments that may require large number of dendritic cells without great expense or use of large number of mice.

  19. Androgen, Estrogen and the Bone Marrow Microenvironment

    DTIC Science & Technology

    2009-12-01

    binding protein-5 expression. Xu C, Graf LF, Fazli L, Coleman IM, Mauldin DE, Li D, Nelson PS, Gleave M, Plymate SR, Cox ME, Torok-Storb BJ, Knudsen BS...Meeting presentations: Xu C, Graf LF, Fazli L, Nelson PS, Plymate SR, Cox ME, Torok-Storb BJ, Knudsen BS (2007) Androgen-regulation of the Bone...Marrow Microenvironment targets IGFBP-5. Innovative Minds in Prostate Cancer Today (IMPaCT). Atlanta, Georgia. P8-7. Xu C, Graf LF, Fazli L

  20. [Fundamental study of blood and bone marrow].

    PubMed

    Miura, Ikuo

    2009-10-01

    The WHO classification incorporated recent advances of immunology, cytogenetics, and molecular biology, which developed from FAB classification based on cell morphology and cytochemistry. One of the most distinct changes was "AML with recurrent genetic abnormalities." The immunological and cytogenetic studies are required to apply the classification to hematopoietic and lymphoid neoplasms in addition to conventional examinations of the blood and bone marrow. The fundamentals of specimen collection, cell counts, morphologic analysis of blood cells, special stains and other laboratory studies were described in related to the management of myeloid leukemias.