Page 218 - 2014 Printable Abstract Book
P. 218
(PS3-50) A nano-scintillator fiber optic detector for high resolution, real-time, in-vivo dose monitoring
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during radiation therapy delivery to mice. Matthew D. Belley ; Ian N. Stanton ; Giao Nguyen ; Hooney
1
2
1
1
1
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Min ; David G. Kirsch ; Steven T. Bache ; John Adamovics ; Mark Oldham ; Michael J. Therien ; Terry T.
2
1
1
Yoshizumi ; Duke University, Durham, NC and Rider University, Lawrence Township, NJ
Preclinical studies involving tumor models in mice require advanced X-ray irradiation geometry
and procedures. As treatment complexity increases, so does the difficulty of performing accurate
treatment planning and quality assurance of dose delivery. Here we present a nano-scintillator fiber optic
detector (NS-FOD) that can achieve sub-millimeter point-dose resolution and perform real time, in-vivo
dose measurements during treatment. We report the angular dependence and in-vivo absolute dose
accuracy of the NS-FOD on the X-rad 225 small animal irradiator compared to a gold standard MOSFET
detector. Calibration of the NS-FOD and a MOSFET were performed free-in-air at 225kVp, by irradiating
adjacent to an ion chamber at three different dose levels. Angular dependence of the MOSFET and NS-
FOD were measured by placing them along the central axis of a tissue equivalent plastic mouse phantom.
The phantom was irradiated at 4 angles: 0, 90, 180, and 270º relative to the cylindrical axis of the
phantom. Next, the NS-FOD and MOSFET were placed side-by-side in the liver of a mouse. Approximately
15cGy was delivered at 225kVp to the mouse liver using both an open field and a 4x4cm square collimated
field. Lastly, we used the NS-FOD to measure a point dose at isocenter in a 3D radiochromic rodent-shaped
dosimeter (Presage), to confirm OD calibrated measurements of the material, utilizing a 20x10mm
collimated beam, and 180º of tube rotation. The NS-FOD dose calibration was linear with an R-squared
value of 0.999999. Angular response changes were within 1% around the fiber axis, on par with the 2%
angular dependence found in the MOSFET. Comparison of the NS-FOD absolute dose to a MOSFET in the
mouse liver yielded 1% difference in open field, and 2% difference when the field size was collimated to
a 4x4cm square. The dose measured in the Presage 3D dosimeter using the NS-FOD was 9.49 Gy (SD ±
0.01 Gy), within 3% of the Presage calibrated OD measurement of 9.21 Gy.
(PS3-51) Sodium nitroprusside as a first-aid medicine for emergency acute exposure to radiation. Hideki
Matsumoto, PhD; BIRC, University of Fukui, Eiheiji-cho, Fukui, Japan
Previously, we found that nitric oxide (NO) is an initiator/mediator of radiation-induced protective
bystander and adaptive responses, indicating that NO plays an important role in biological defense
response to radiation. These findings imply that NO may possess abilities which protect cells, tissues and
individuals from radiation injury, and which impose a recovery of radiation damage. According to the
hypothesis, several years ago, I started the development of first-aid medicines for emergency acute
exposure to radiation on the assumption of NO-generating agents. Five medicines for angina pectoris
were examined to have a protective ability to radiation injury using normal human fibroblast AG1522 cells.
All medicines reveal a protective ability as a recovery of surviving fraction against X-irradiation in the
clonogenic assay. In mice experiment, sodium nitroprusside (SNP) alone reveals a protective ability as a
rescue of mice irradiated with X-rays at around LD50 dose. Although the surviving rate of mice irradiated
with X-rays at 6.5 Gy was ca. 40%, the surviving rate of the mice was increased to ca. 80% by the
administration with SNP. On Day 14, white blood cells and platelets in X-irradiated mice were almost
empty. On the other hand, their cells in X-irradiated mice were resumed by the administration with SNP.
216 | P a g e
1
1
1
during radiation therapy delivery to mice. Matthew D. Belley ; Ian N. Stanton ; Giao Nguyen ; Hooney
1
2
1
1
1
1
Min ; David G. Kirsch ; Steven T. Bache ; John Adamovics ; Mark Oldham ; Michael J. Therien ; Terry T.
2
1
1
Yoshizumi ; Duke University, Durham, NC and Rider University, Lawrence Township, NJ
Preclinical studies involving tumor models in mice require advanced X-ray irradiation geometry
and procedures. As treatment complexity increases, so does the difficulty of performing accurate
treatment planning and quality assurance of dose delivery. Here we present a nano-scintillator fiber optic
detector (NS-FOD) that can achieve sub-millimeter point-dose resolution and perform real time, in-vivo
dose measurements during treatment. We report the angular dependence and in-vivo absolute dose
accuracy of the NS-FOD on the X-rad 225 small animal irradiator compared to a gold standard MOSFET
detector. Calibration of the NS-FOD and a MOSFET were performed free-in-air at 225kVp, by irradiating
adjacent to an ion chamber at three different dose levels. Angular dependence of the MOSFET and NS-
FOD were measured by placing them along the central axis of a tissue equivalent plastic mouse phantom.
The phantom was irradiated at 4 angles: 0, 90, 180, and 270º relative to the cylindrical axis of the
phantom. Next, the NS-FOD and MOSFET were placed side-by-side in the liver of a mouse. Approximately
15cGy was delivered at 225kVp to the mouse liver using both an open field and a 4x4cm square collimated
field. Lastly, we used the NS-FOD to measure a point dose at isocenter in a 3D radiochromic rodent-shaped
dosimeter (Presage), to confirm OD calibrated measurements of the material, utilizing a 20x10mm
collimated beam, and 180º of tube rotation. The NS-FOD dose calibration was linear with an R-squared
value of 0.999999. Angular response changes were within 1% around the fiber axis, on par with the 2%
angular dependence found in the MOSFET. Comparison of the NS-FOD absolute dose to a MOSFET in the
mouse liver yielded 1% difference in open field, and 2% difference when the field size was collimated to
a 4x4cm square. The dose measured in the Presage 3D dosimeter using the NS-FOD was 9.49 Gy (SD ±
0.01 Gy), within 3% of the Presage calibrated OD measurement of 9.21 Gy.
(PS3-51) Sodium nitroprusside as a first-aid medicine for emergency acute exposure to radiation. Hideki
Matsumoto, PhD; BIRC, University of Fukui, Eiheiji-cho, Fukui, Japan
Previously, we found that nitric oxide (NO) is an initiator/mediator of radiation-induced protective
bystander and adaptive responses, indicating that NO plays an important role in biological defense
response to radiation. These findings imply that NO may possess abilities which protect cells, tissues and
individuals from radiation injury, and which impose a recovery of radiation damage. According to the
hypothesis, several years ago, I started the development of first-aid medicines for emergency acute
exposure to radiation on the assumption of NO-generating agents. Five medicines for angina pectoris
were examined to have a protective ability to radiation injury using normal human fibroblast AG1522 cells.
All medicines reveal a protective ability as a recovery of surviving fraction against X-irradiation in the
clonogenic assay. In mice experiment, sodium nitroprusside (SNP) alone reveals a protective ability as a
rescue of mice irradiated with X-rays at around LD50 dose. Although the surviving rate of mice irradiated
with X-rays at 6.5 Gy was ca. 40%, the surviving rate of the mice was increased to ca. 80% by the
administration with SNP. On Day 14, white blood cells and platelets in X-irradiated mice were almost
empty. On the other hand, their cells in X-irradiated mice were resumed by the administration with SNP.
216 | P a g e
