SU-E-T-650: Impact of Machine Output Rate on Effective Dose Rate and Biologically Equivalent Fraction Size in Total Body Irradiation (TBI)

2011 ◽  
Vol 38 (6Part21) ◽  
pp. 3639-3639
Author(s):  
RD Stewart ◽  
A Kalet ◽  
GE Laramore
Keyword(s):  
Effective Dose ◽  
Dose Rate ◽  
Total Body Irradiation ◽  
Output Rate ◽  
Equivalent Fraction ◽  
Fraction Size ◽  
Effective Dose Rate ◽  
Total Body

Indoor Radon and Thoron Concentration and the Associated Effective Dose Rate Determination in Dwellings of Suq Alshouk, Thiqar (Iraq)

2021 ◽  
Vol 19 (12) ◽  
pp. 06-10
Author(s):  
Hussam Najem Abood ◽  
Ahmed Abbas Mohamed
Keyword(s):  
Effective Dose ◽  
Dose Rate ◽  
Annual Effective Dose ◽  
Indoor Radon ◽  
Type Ii ◽  
Average Value ◽  
Effective Dose Rate

Indoor radon/thoron concentration has been determined in some dwellings of Suq Alshouk district in Thiqar Governorate southern of Iraq, using LR-115 type II and CR-39 (SSNTDs). In this work the indoor radon/thoron concentration varies from (8-73) Bq m-3 for radon with an average 35±2Bq m-3, and ranges (1- 47) Bq m-3 for thoron with an average16±2Bq m-3. The average annual effective dose due to radon and thoron varies from 0.43-3.38m Sv y-1 with average value 1.43±0.11 mSv y-1.

scholarly journals Syngeneic and allogeneic bone marrow engraftment after total body irradiation: dependence on dose, dose rate, and fractionation

Blood ◽  
1991 ◽  
Vol 77 (3) ◽  
pp. 661-669 ◽  
Author(s):  
JD Down ◽  
NJ Tarbell ◽  
HD Thames ◽  
PM Mauch
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Radiation Dose ◽  
Dose Rate ◽  
Dose Response ◽  
Total Body Irradiation ◽  
Low Dose ◽  
Allogeneic Bone ◽  
Low Dose Rate ◽  
Total Body

Abstract Murine bone marrow chimera models were used to assess the efficacy of host total body irradiation (TBI) given at different doses, dose rates, and fractionation schemes in providing for engraftment of syngeneic and allogeneic bone marrow. B6-Hbbd congenic and LP mice, respectively, were used as donors (10(7) bone marrow cells) for syngeneic and allogenic (H-2 compatible) transplantation in standard B6 recipients. Stable marrow chimerism was determined from host and donor stem cell- derived hemoglobin phenotypes (Hbbs and Hbbd) on gel electrophoresis at 3 months posttransplant. Partial engraftment of syngeneic marrow was seen at single doses as low as 2 Gy, with the donor component increasing steadily with increasing TBI dose to a level of 100% at 7 Gy. Immunologic resistance of the host appeared to prevent allogeneic engraftment until 5.5 Gy. A very steep radiation dose response was then observed so that the level of chimerism with 6 Gy and above became comparable with syngeneic engraftment. Low dose rate (5 cGy minute-1) and fractionated TBI required higher total doses for equivalent engraftment (radiation dose-sparing) in both syngeneic and allogenic bone marrow transplantation. This displacement in the dose-response curve on fractionation was seen with interfraction intervals of 3 and 6 hours. A further dose-sparing effect was observed on extending the interval to 18 and 24 hours, but only for allogeneic transplantation, and may therefore be related to recovery of immune-mediated graft resistance. The involvement of multiple target cell populations in determining allogenic engraftment rendered the application of the linear-quadratic model for radiation cell survival problematic in this case. The recovery in dose when low dose rate and 6-hour interfraction intervals were applied in either syngeneic or allogeneic BMT is consistent with appreciable sub-lethal damage repair in the primitive self-renewing stem cell population of the host marrow. These results contrast with the poor repair capacity of the 11-day spleen colony- forming units (CFUs) population after fractionated irradiation and support the notion that ablation of early stem cells in the pre-CFUs compartment is essential for long-term marrow engraftment.

Assessment of radioactivity from selected soil samples from Halfa Aljadida area, Sudan

2019 ◽  
Vol 107 (6) ◽  
pp. 489-502
Author(s):  
Abd-Elmoniem A. Elzain ◽  
Hajo Idriss ◽  
Yousif Sh. Mohammed ◽  
Khidir Shaib Mohamed ◽  
Mohamed Abd Elwahab Mohamed Ali ◽  
...  
Keyword(s):  
Effective Dose ◽  
Dose Rate ◽  
Linear Correlation ◽  
Radon Concentration ◽  
Soil Samples ◽  
Average Value ◽  
Soil Gas Radon ◽  
Effective Dose Rate ◽  
Alpha Index ◽  
Concentration Surface

Abstract In this research, the results of radon concentration, surface and mass exhalation rates, radium concentration, effective dose rate and the alpha index have been investigated in a number of 198 soil samples that have been collected from various residential locations of Halfa Aljadida area, Sudan. The can technique, containing CR-39 have been used. From our results, the average value of soil gas radon concentration was found to be 1.96±0.22 kBq·m−3. The average values of surface and mass exhalation rates were 1.73±0.19 Bq·m−2·h−1 and 34.79±3.87 mBq·kg−1·h−1, respectively. The radium concentration average value was 8.06±0.90 Bq·kg−1. While the average value of the effective dose rate was recorded to be 54.69±6.11 mSv·y−1. The average value of alpha index of studied samples was (4.03±0.45)×10−2. From the study, a good positive and linear correlation between radium concentration, surface and mass exhalation rates of soil samples were present. In addition to that, a positive and linear correlation between radium and radon concentrations was found. Finally, a comparison between the results and other findings was conducted and the results imply the fact that the area under consideration is safe as if the health hazard are mentioned.

scholarly journals Effect of dose rate on pulmonary toxicity in patients with hematolymphoid malignancies undergoing total body irradiation

2018 ◽  
Vol 13 (1) ◽  
Author(s):  
Dong-Yun Kim ◽  
Il Han Kim ◽  
Sung-Soo Yoon ◽  
Hyoung Jin Kang ◽  
Hee Young Shin ◽  
...  
Keyword(s):  
Dose Rate ◽  
Total Body Irradiation ◽  
Pulmonary Toxicity ◽  
Total Body

scholarly journals Fractionated versus single-dose total body irradiation at low and high dose rates to condition canine littermates for DLA-identical marrow grafts

Blood ◽  
1994 ◽  
Vol 83 (11) ◽  
pp. 3384-3389 ◽  
Author(s):  
R Storb ◽  
RF Raff ◽  
FR Appelbaum ◽  
HJ Deeg ◽  
TC Graham ◽  
...  
Keyword(s):  
Dna Repair ◽  
Single Dose ◽  
Dose Rate ◽  
Total Body Irradiation ◽  
High Dose Rate ◽  
Lymphoid Cells ◽  
High Dose ◽  
Dose Rates ◽  
Total Body ◽  
Allogeneic Marrow

Abstract We explored in dogs the immunosuppressive properties of 450 cGy total body irradiation (TBI) delivered from two opposing 60Co sources, as assessed by the criterion of successful engraftment of allogeneic genotypically DLA-identical littermate marrow. Two questions were asked in this study. Firstly, does dose rate affect the immunosuppressive effect of TBI when administered in a single dose? Secondly, does fractionation alter the immunosuppression of TBI when delivered at a very fast dose rate? Dose rates studied included 7 and 70 cGy/min, and fractionation involved four fractions of 112.5 cGy each, with 6-hour minimum interfraction intervals. Six of 7 dogs receiving 450 cGy single- dose TBI at 70 cGy/min showed sustained engraftment of the allogeneic marrow, compared with 1 of 7 dogs receiving single-dose TBI at 7 cGy/min (P = .01). Fractionated TBI at 70 cGy/min resulted in sustained allogeneic engraftment in 3 of 10 dogs, a result that was statistically significantly worse than that with single-dose TBI at 70 cGy/min (P = .03) and not statistically different (P = .24) from that with fractionated TBI delivered at 7 cGy/min (0 of 5 dogs engrafted). A single dose of 450 cGy of TBI delivered at a rate of 70 cGy/min is significantly more immunosuppressive than the same total dose delivered at 7 cGy/min. Fractionated TBI at 70 cGy/min is significantly less immunosuppressive than single-dose TBI at 70 cGy/min and not significantly different from fractionated TBI administered at 7 cGy/min. Results are consistent with the notion that significant DNA repair in lymphoid cells is possible during interfraction intervals at the relatively high dose rate of 70 cGy/min.

scholarly journals Upgrade of GLE database: Assessment of effective dose rate at flight altitude

2018 ◽  
Vol 62 (2) ◽  
pp. 398-407 ◽  
Author(s):  
S. Tuohino ◽  
A. Ibragimov ◽  
I. Usoskin ◽  
A. Mishev
Keyword(s):  
Effective Dose ◽  
Dose Rate ◽  
Flight Altitude ◽  
Effective Dose Rate

scholarly journals Technical and radiological characterisation of fly ash and bottom ash from thermal power plant

2021 ◽  
Author(s):  
Emilija Fidanchevski ◽  
Biljana Angjusheva ◽  
Vojo Jovanov ◽  
Pece Murtanovski ◽  
Ljubica Vladiceska ◽  
...  
Keyword(s):  
Fly Ash ◽  
Effective Dose ◽  
Dose Rate ◽  
Power Plants ◽  
Annual Effective Dose ◽  
Health Effect ◽  
Thermal Power ◽  
Bottom Ash ◽  
Effective Dose Rate ◽  
Annual Effective Dose Rate

AbstractHuge quantities of fly ash and bottom ash are generated from thermal power plants and it presents great concern for country, mainly due to the environmental effects. In this study, fly ashes and bottom ash were characterized from technical and radiological aspects. Health effect due to the activity of radionuclides 226Ra, 232Th and 40K was estimated via radium equivalent activity (Raeq), external hazards index (Hex), the external absorbed dose rate (D) and annual effective dose rate (EDR). The specific surface area (40.25 m2 g−1), particle density (1.88 g cm−3) and LOI (23.49%) were typical for bottom ash. Siliceous fly ash contained 32% reactive silica. The annual effective dose rate for all ashes is ≤ 0.2 mSv y−1. Both, fly ash and bottom ash present potential secondary raw materials to be used for building purposes as result of their technological and radiological assessment.

scholarly journals Syngeneic and allogeneic bone marrow engraftment after total body irradiation: dependence on dose, dose rate, and fractionation

Blood ◽  
1991 ◽  
Vol 77 (3) ◽  
pp. 661-669 ◽  
Author(s):  
JD Down ◽  
NJ Tarbell ◽  
HD Thames ◽  
PM Mauch
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Radiation Dose ◽  
Dose Rate ◽  
Dose Response ◽  
Total Body Irradiation ◽  
Low Dose ◽  
Allogeneic Bone ◽  
Low Dose Rate ◽  
Total Body

Murine bone marrow chimera models were used to assess the efficacy of host total body irradiation (TBI) given at different doses, dose rates, and fractionation schemes in providing for engraftment of syngeneic and allogeneic bone marrow. B6-Hbbd congenic and LP mice, respectively, were used as donors (10(7) bone marrow cells) for syngeneic and allogenic (H-2 compatible) transplantation in standard B6 recipients. Stable marrow chimerism was determined from host and donor stem cell- derived hemoglobin phenotypes (Hbbs and Hbbd) on gel electrophoresis at 3 months posttransplant. Partial engraftment of syngeneic marrow was seen at single doses as low as 2 Gy, with the donor component increasing steadily with increasing TBI dose to a level of 100% at 7 Gy. Immunologic resistance of the host appeared to prevent allogeneic engraftment until 5.5 Gy. A very steep radiation dose response was then observed so that the level of chimerism with 6 Gy and above became comparable with syngeneic engraftment. Low dose rate (5 cGy minute-1) and fractionated TBI required higher total doses for equivalent engraftment (radiation dose-sparing) in both syngeneic and allogenic bone marrow transplantation. This displacement in the dose-response curve on fractionation was seen with interfraction intervals of 3 and 6 hours. A further dose-sparing effect was observed on extending the interval to 18 and 24 hours, but only for allogeneic transplantation, and may therefore be related to recovery of immune-mediated graft resistance. The involvement of multiple target cell populations in determining allogenic engraftment rendered the application of the linear-quadratic model for radiation cell survival problematic in this case. The recovery in dose when low dose rate and 6-hour interfraction intervals were applied in either syngeneic or allogeneic BMT is consistent with appreciable sub-lethal damage repair in the primitive self-renewing stem cell population of the host marrow. These results contrast with the poor repair capacity of the 11-day spleen colony- forming units (CFUs) population after fractionated irradiation and support the notion that ablation of early stem cells in the pre-CFUs compartment is essential for long-term marrow engraftment.

SU-E-T-320: Low Dose Rate Pediatric Total Body Irradiation (TBI) Using TrueBeam

2013 ◽  
Vol 40 (6Part15) ◽  
pp. 278-278 ◽  
Author(s):  
N Knutson ◽  
S Yaddanapudi ◽  
H Li
Keyword(s):  
Dose Rate ◽  
Total Body Irradiation ◽  
Low Dose ◽  
Low Dose Rate ◽  
Total Body
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