The Experts below are selected from a list of 15693 Experts worldwide ranked by ideXlab platform
Peter Obrien - One of the best experts on this subject based on the ideXlab platform.
-
a radiation badge Survey for family members living with patients treated with a 103pd permanent breast seed implant
International Journal of Radiation Oncology Biology Physics, 2008Co-Authors: Brian M Keller, Jeanphilippe Pignol, Eileen Rakovitch, Raxa Sankreacha, Peter ObrienAbstract:Purpose Sixty-seven patients with early-stage breast cancer were treated in a Phase I/II clinical trial using a 103 Pd permanent breast seed implant as adjuvant radiotherapy after breast-conserving surgery. We report the dose received by family members living with these patients and compare measured doses with theoretical worst-case scenario estimates. Methods and Materials Exposure-rate measurements were taken at 1 m from the patient by using a calibrated low-energy Survey Meter. Landauer (Landauer Inc., Glenwood, IL) Luxel badges, with sensitivity of 0.01 mSv, were given to family members to wear after the implantation. Badge readings for 33 spouses and 28 other family members were used to estimate effective doses, and these were compared with theory. Results Average preimplantation planning target volume from computed tomography was 50.3 ml (range, 18.0–96.7 ml), and average preimplantation distance between the skin and the most anterior planning target volume margin was 0.57 cm. The average maximum exposure rate was measured to be 2.4 ± 1.1 mR/h, and average measured dose to a spouse was 0.99 ± 1.0 mSv. The calculated exposure rates and spousal doses using preimplantation computed tomography scan data overestimated those measured. Average measured family member dose (excluding spouses) was 0.20 ± 0.58 mSv. Conclusions Based on measured and calculated spousal doses, a permanent breast seed implant using 103 Pd is safe for the public. However, it is recommended that extra precautions in the way of a breast patch be used when patients with an implant will be in the vicinity of toddlers or pregnant women.
-
a permanent breast seed implant as partial breast radiation therapy for early stage patients a comparison of palladium 103 and iodine 125 isotopes based on radiation safety considerations
International Journal of Radiation Oncology Biology Physics, 2005Co-Authors: Brian M Keller, Eileen Rakovitch, Raxa Sankreacha, Peter Obrien, Jeanphilippe PignolAbstract:Purpose: A permanent breast seed implant (PBSI) technique has been developed as a new form of partial adjuvant radiation therapy for early-stage breast cancer. This study compares iodine-125 ( 125 I) and palladium-103 ( 103 Pd) isotopes by examining the exposure and effective dose (ED) to a patient's partner. Methods and Materials: A low-energy Survey Meter was used to measure exposure rates as a function of bolus thickness placed over 103 Pd or 125 I seeds. A general mathematical expression for the initial exposure rate at 1 m ( x o,1m ) from the skin surface as a function of the implant size, R , and the distance between the skin surface and the implant, d , was derived. Also, a second general equation is proposed to calculate the ED to the patient's partner. Results: The initial exposure rate at 1 Meter and the ED are calculated as follows: x o,1m = 3 α 2 R 3 ; ⋅ ; β 3 [ e −β(2R+d) (β R + 1) + e −β⋅d (β R − 1)], and ED = aR b ⋅ [ e −c(2R+d) ⋅ ( cR + 1) + e −cd ⋅ ( cR − 1)]. For 125 I, the paraMeters are: α = 0.154409, β = 0.388460, a = 197, b = −0.95, and c = 0.38846. For 103 Pd, they are: α = 0.06877, β = 0.421098, a = 18.6, b = −0.78, and c = 0.421098. For implant diaMeters varying from 2 to 6 cm and skin-to-implant distances varying from 0.7 to 4 cm, the ED is consistently below 2.6 mSv using the 103 Pd isotope, but more than 5 mSv in many instances and possibly up to 20 mSv using 125 I. Conclusions: PBSI using 103 Pd seeds appears safe because the patient's partner ED is consistently below 5 mSv. The 125 I isotope is not recommended for PBSI.
Jeanphilippe Pignol - One of the best experts on this subject based on the ideXlab platform.
-
a radiation badge Survey for family members living with patients treated with a 103pd permanent breast seed implant
International Journal of Radiation Oncology Biology Physics, 2008Co-Authors: Brian M Keller, Jeanphilippe Pignol, Eileen Rakovitch, Raxa Sankreacha, Peter ObrienAbstract:Purpose Sixty-seven patients with early-stage breast cancer were treated in a Phase I/II clinical trial using a 103 Pd permanent breast seed implant as adjuvant radiotherapy after breast-conserving surgery. We report the dose received by family members living with these patients and compare measured doses with theoretical worst-case scenario estimates. Methods and Materials Exposure-rate measurements were taken at 1 m from the patient by using a calibrated low-energy Survey Meter. Landauer (Landauer Inc., Glenwood, IL) Luxel badges, with sensitivity of 0.01 mSv, were given to family members to wear after the implantation. Badge readings for 33 spouses and 28 other family members were used to estimate effective doses, and these were compared with theory. Results Average preimplantation planning target volume from computed tomography was 50.3 ml (range, 18.0–96.7 ml), and average preimplantation distance between the skin and the most anterior planning target volume margin was 0.57 cm. The average maximum exposure rate was measured to be 2.4 ± 1.1 mR/h, and average measured dose to a spouse was 0.99 ± 1.0 mSv. The calculated exposure rates and spousal doses using preimplantation computed tomography scan data overestimated those measured. Average measured family member dose (excluding spouses) was 0.20 ± 0.58 mSv. Conclusions Based on measured and calculated spousal doses, a permanent breast seed implant using 103 Pd is safe for the public. However, it is recommended that extra precautions in the way of a breast patch be used when patients with an implant will be in the vicinity of toddlers or pregnant women.
-
a permanent breast seed implant as partial breast radiation therapy for early stage patients a comparison of palladium 103 and iodine 125 isotopes based on radiation safety considerations
International Journal of Radiation Oncology Biology Physics, 2005Co-Authors: Brian M Keller, Eileen Rakovitch, Raxa Sankreacha, Peter Obrien, Jeanphilippe PignolAbstract:Purpose: A permanent breast seed implant (PBSI) technique has been developed as a new form of partial adjuvant radiation therapy for early-stage breast cancer. This study compares iodine-125 ( 125 I) and palladium-103 ( 103 Pd) isotopes by examining the exposure and effective dose (ED) to a patient's partner. Methods and Materials: A low-energy Survey Meter was used to measure exposure rates as a function of bolus thickness placed over 103 Pd or 125 I seeds. A general mathematical expression for the initial exposure rate at 1 m ( x o,1m ) from the skin surface as a function of the implant size, R , and the distance between the skin surface and the implant, d , was derived. Also, a second general equation is proposed to calculate the ED to the patient's partner. Results: The initial exposure rate at 1 Meter and the ED are calculated as follows: x o,1m = 3 α 2 R 3 ; ⋅ ; β 3 [ e −β(2R+d) (β R + 1) + e −β⋅d (β R − 1)], and ED = aR b ⋅ [ e −c(2R+d) ⋅ ( cR + 1) + e −cd ⋅ ( cR − 1)]. For 125 I, the paraMeters are: α = 0.154409, β = 0.388460, a = 197, b = −0.95, and c = 0.38846. For 103 Pd, they are: α = 0.06877, β = 0.421098, a = 18.6, b = −0.78, and c = 0.421098. For implant diaMeters varying from 2 to 6 cm and skin-to-implant distances varying from 0.7 to 4 cm, the ED is consistently below 2.6 mSv using the 103 Pd isotope, but more than 5 mSv in many instances and possibly up to 20 mSv using 125 I. Conclusions: PBSI using 103 Pd seeds appears safe because the patient's partner ED is consistently below 5 mSv. The 125 I isotope is not recommended for PBSI.
Brian M Keller - One of the best experts on this subject based on the ideXlab platform.
-
a radiation badge Survey for family members living with patients treated with a 103pd permanent breast seed implant
International Journal of Radiation Oncology Biology Physics, 2008Co-Authors: Brian M Keller, Jeanphilippe Pignol, Eileen Rakovitch, Raxa Sankreacha, Peter ObrienAbstract:Purpose Sixty-seven patients with early-stage breast cancer were treated in a Phase I/II clinical trial using a 103 Pd permanent breast seed implant as adjuvant radiotherapy after breast-conserving surgery. We report the dose received by family members living with these patients and compare measured doses with theoretical worst-case scenario estimates. Methods and Materials Exposure-rate measurements were taken at 1 m from the patient by using a calibrated low-energy Survey Meter. Landauer (Landauer Inc., Glenwood, IL) Luxel badges, with sensitivity of 0.01 mSv, were given to family members to wear after the implantation. Badge readings for 33 spouses and 28 other family members were used to estimate effective doses, and these were compared with theory. Results Average preimplantation planning target volume from computed tomography was 50.3 ml (range, 18.0–96.7 ml), and average preimplantation distance between the skin and the most anterior planning target volume margin was 0.57 cm. The average maximum exposure rate was measured to be 2.4 ± 1.1 mR/h, and average measured dose to a spouse was 0.99 ± 1.0 mSv. The calculated exposure rates and spousal doses using preimplantation computed tomography scan data overestimated those measured. Average measured family member dose (excluding spouses) was 0.20 ± 0.58 mSv. Conclusions Based on measured and calculated spousal doses, a permanent breast seed implant using 103 Pd is safe for the public. However, it is recommended that extra precautions in the way of a breast patch be used when patients with an implant will be in the vicinity of toddlers or pregnant women.
-
a permanent breast seed implant as partial breast radiation therapy for early stage patients a comparison of palladium 103 and iodine 125 isotopes based on radiation safety considerations
International Journal of Radiation Oncology Biology Physics, 2005Co-Authors: Brian M Keller, Eileen Rakovitch, Raxa Sankreacha, Peter Obrien, Jeanphilippe PignolAbstract:Purpose: A permanent breast seed implant (PBSI) technique has been developed as a new form of partial adjuvant radiation therapy for early-stage breast cancer. This study compares iodine-125 ( 125 I) and palladium-103 ( 103 Pd) isotopes by examining the exposure and effective dose (ED) to a patient's partner. Methods and Materials: A low-energy Survey Meter was used to measure exposure rates as a function of bolus thickness placed over 103 Pd or 125 I seeds. A general mathematical expression for the initial exposure rate at 1 m ( x o,1m ) from the skin surface as a function of the implant size, R , and the distance between the skin surface and the implant, d , was derived. Also, a second general equation is proposed to calculate the ED to the patient's partner. Results: The initial exposure rate at 1 Meter and the ED are calculated as follows: x o,1m = 3 α 2 R 3 ; ⋅ ; β 3 [ e −β(2R+d) (β R + 1) + e −β⋅d (β R − 1)], and ED = aR b ⋅ [ e −c(2R+d) ⋅ ( cR + 1) + e −cd ⋅ ( cR − 1)]. For 125 I, the paraMeters are: α = 0.154409, β = 0.388460, a = 197, b = −0.95, and c = 0.38846. For 103 Pd, they are: α = 0.06877, β = 0.421098, a = 18.6, b = −0.78, and c = 0.421098. For implant diaMeters varying from 2 to 6 cm and skin-to-implant distances varying from 0.7 to 4 cm, the ED is consistently below 2.6 mSv using the 103 Pd isotope, but more than 5 mSv in many instances and possibly up to 20 mSv using 125 I. Conclusions: PBSI using 103 Pd seeds appears safe because the patient's partner ED is consistently below 5 mSv. The 125 I isotope is not recommended for PBSI.
Shigenobu Nagataki - One of the best experts on this subject based on the ideXlab platform.
-
measurements of individual radiation doses in residents living around the fukushima nuclear power plant
Radiation Research, 2013Co-Authors: Shigenobu Nagataki, Noboru Takamura, Kenji Kamiya, Makoto AkashiAbstract:At the outset of the accident at Fukushima Daiichi Nuclear Power Plant in March 2011, the radiation doses experienced by residents were calculated from the readings at monitoring posts, with several assumptions being made from the point of view of protection and safety. However, health effects should also be estimated by obtaining measurements of the individual radiation doses. The individual external radiation doses, determined by a behavior Survey in the “evacuation and deliberate evacuation area” in the first 4 months, were <5 mSv in 97.4% of residents (maximum: 15 mSv). Doses in Fukushima Prefecture were <3 mSv in 99.3% of 386,572 residents analyzed. External doses in Fukushima City determined by personal dosiMeters were <1 mSv/3 months (September–November, 2011) in 99.7% of residents (maximum: 2.7 mSv). Thyroid radiation doses, determined in March using a NaI (TI) scintillation Survey Meter in children in the evacuation and deliberate evacuation area, were <10 mSv in 95.7% of children (maximum: 35 mS...
Takashi Nakamura - One of the best experts on this subject based on the ideXlab platform.
-
development of lightweight portable neutron Survey Meter
Journal of Nuclear Science and Technology, 2017Co-Authors: Tomoya Nunomiya, Takashi Nakamura, Seini Yamamura, Takahiro AmanoAbstract:We have developed a lightweight portable neutron Survey Meter comprising a proportional gas counter containing a mixed gas of methane gas and nitrogen gas for measuring the ambient neutron dose e...
-
development of a light weight portable neutron Survey Meter
Radiation Protection Dosimetry, 2011Co-Authors: Tomoya Nunomiya, Takashi Nakamura, Tetsuo Koyama, Daisuke Inui, Takeshi IshikuraAbstract:A light-weight portable neutron Survey Meter was developed using a mixed organic gas counter for dose management at nuclear power plants and accelerator facilities. This Survey Meter, NSN31041, is ~2 kg in weight and W160×H250×L300 mm(3) in size, which is capable of measuring neutron ambient dose equivalent rate from thermal to 15 MeV neutrons. The neutron energy response of the Survey Meter is evaluated using continuous energy neutron sources of (252)Cf, (241)Am-Be, thermal neutrons generated from a graphite pile loading a (252)Cf source, concrete-moderated neutrons of (241)Am-Be source and D(2)O-moderated neutrons of (252)Cf source. The measured response data show very good agreement with neutron ambient dose equivalent within a 50 % deviation.
-
development of wide energy range x γ ray Survey Meter
Journal of Nuclear Science and Technology, 2008Co-Authors: Seini Yamamura, Takashi Nakamura, Katsuhito Itou, Osamu Hatakeyama, Kaoru MasuiAbstract:The X-ray radiation produced from various X-ray generating machines has energies between 8 keV to 300 keV and for monitoring environmental gamma rays, the energy range to be measured is from 40 keV up to 1500 keV. We developed a wide-energy range X/γ-ray Survey-Meter , which can measure ambient dose equivalent H*(10), covering the energy range of 8 keV to 1500 keV by dividing the two energy ranges, from 8 to 300keV for X-ray mode and from 40 to 1500keV for γ-ray mode, both energy responses are within 25% from 10keV up to 300keV and from 50keV up to 1500keV using a 12.7mm diaMeter by 12.7mm thick NaI(Tl) scintillator.
