Abstract
Purpose: To compare possible neutron doses produced in scanning and scattering modes, with the latter assessed using a newly built passive-scattering proton beam line. Methods and Materials: A 40 × 30.5 × 30-cm water phantom was irradiated with 230-MeV proton beams using a gantry angle of 270°, a 10-cm-diameter snout, and a brass aperture with a diameter of 7 cm and a thickness of 6.5 cm. The secondary neutron doses during irradiation were measured at various points using CR-39 detectors, and these measurements were cross-checked using a neutron survey meter with a 22-cm range and a 5-cm spread-out Bragg peak. Results: The maximum doses due to secondary neutrons produced by a scattering beam-delivery system were on the order of 0.152 mSv/Gy and 1.17 mSv/Gy at 50 cm from the beam isocenter in the longitudinal (0°) and perpendicular (90°) directions, respectively. The neutron dose equivalent to the proton absorbed dose, measured from 10 cm to 100 cm from the isocenter, ranged from 0.071 mSv/Gy to 1.96 mSv/Gy in the direction of the beam line (i.e., φ = 0°). The largest neutron dose, of 3.88 mSv/Gy, was observed at 135° and 25 cm from the isocenter. Conclusions: Although the secondary neutron doses in proton therapy were higher when a scattering mode rather than a scanning mode was used, they did not exceed the scattered photon dose in typical photon treatments.
| Original language | English |
|---|---|
| Pages (from-to) | 260-265 |
| Number of pages | 6 |
| Journal | International Journal of Radiation Oncology Biology Physics |
| Volume | 74 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2009 May 1 |
| Externally published | Yes |
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Keywords
- CR-39
- Neutron dose
- Proton
- Secondary neutron
ASJC Scopus subject areas
- Oncology
- Radiology Nuclear Medicine and imaging
- Radiation
- Cancer Research
Cite this
Secondary Neutron Doses for Several Beam Configurations for Proton Therapy. / Shin, Dongho; Yoon, Myonggeun; Kwak, Jungwon; Shin, Jungwook; Lee, Se Byeong; Park, Sung Yong; Park, Soah; Kim, Dae Yong; Cho, Kwan Ho.
In: International Journal of Radiation Oncology Biology Physics, Vol. 74, No. 1, 01.05.2009, p. 260-265.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Secondary Neutron Doses for Several Beam Configurations for Proton Therapy
AU - Shin, Dongho
AU - Yoon, Myonggeun
AU - Kwak, Jungwon
AU - Shin, Jungwook
AU - Lee, Se Byeong
AU - Park, Sung Yong
AU - Park, Soah
AU - Kim, Dae Yong
AU - Cho, Kwan Ho
PY - 2009/5/1
Y1 - 2009/5/1
N2 - Purpose: To compare possible neutron doses produced in scanning and scattering modes, with the latter assessed using a newly built passive-scattering proton beam line. Methods and Materials: A 40 × 30.5 × 30-cm water phantom was irradiated with 230-MeV proton beams using a gantry angle of 270°, a 10-cm-diameter snout, and a brass aperture with a diameter of 7 cm and a thickness of 6.5 cm. The secondary neutron doses during irradiation were measured at various points using CR-39 detectors, and these measurements were cross-checked using a neutron survey meter with a 22-cm range and a 5-cm spread-out Bragg peak. Results: The maximum doses due to secondary neutrons produced by a scattering beam-delivery system were on the order of 0.152 mSv/Gy and 1.17 mSv/Gy at 50 cm from the beam isocenter in the longitudinal (0°) and perpendicular (90°) directions, respectively. The neutron dose equivalent to the proton absorbed dose, measured from 10 cm to 100 cm from the isocenter, ranged from 0.071 mSv/Gy to 1.96 mSv/Gy in the direction of the beam line (i.e., φ = 0°). The largest neutron dose, of 3.88 mSv/Gy, was observed at 135° and 25 cm from the isocenter. Conclusions: Although the secondary neutron doses in proton therapy were higher when a scattering mode rather than a scanning mode was used, they did not exceed the scattered photon dose in typical photon treatments.
AB - Purpose: To compare possible neutron doses produced in scanning and scattering modes, with the latter assessed using a newly built passive-scattering proton beam line. Methods and Materials: A 40 × 30.5 × 30-cm water phantom was irradiated with 230-MeV proton beams using a gantry angle of 270°, a 10-cm-diameter snout, and a brass aperture with a diameter of 7 cm and a thickness of 6.5 cm. The secondary neutron doses during irradiation were measured at various points using CR-39 detectors, and these measurements were cross-checked using a neutron survey meter with a 22-cm range and a 5-cm spread-out Bragg peak. Results: The maximum doses due to secondary neutrons produced by a scattering beam-delivery system were on the order of 0.152 mSv/Gy and 1.17 mSv/Gy at 50 cm from the beam isocenter in the longitudinal (0°) and perpendicular (90°) directions, respectively. The neutron dose equivalent to the proton absorbed dose, measured from 10 cm to 100 cm from the isocenter, ranged from 0.071 mSv/Gy to 1.96 mSv/Gy in the direction of the beam line (i.e., φ = 0°). The largest neutron dose, of 3.88 mSv/Gy, was observed at 135° and 25 cm from the isocenter. Conclusions: Although the secondary neutron doses in proton therapy were higher when a scattering mode rather than a scanning mode was used, they did not exceed the scattered photon dose in typical photon treatments.
KW - CR-39
KW - Neutron dose
KW - Proton
KW - Secondary neutron
UR - http://www.scopus.com/inward/record.url?scp=64049084839&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=64049084839&partnerID=8YFLogxK
U2 - 10.1016/j.ijrobp.2008.10.090
DO - 10.1016/j.ijrobp.2008.10.090
M3 - Article
C2 - 19362245
AN - SCOPUS:64049084839
VL - 74
SP - 260
EP - 265
JO - International Journal of Radiation Oncology Biology Physics
JF - International Journal of Radiation Oncology Biology Physics
SN - 0360-3016
IS - 1
ER -