Abstract
Dose response relationships were determined after hemibrain x-irradiation of normal beagle dogs. Radiation doses of 11.5, 13.5, 14.3, and 17 Gy were delivered in a single dose and results were compared to previous studies using doses of 15 and 30 Gy. Brain injury was quantified using computed tomography (CT), with serial studies obtained monthly up to 1 year following irradiation. Quantitative endpoints included low density volume and contrast enhancement. Doses above 14.3 Gy resulted in high lethality 5-8 months following irradiation, and an LD50 of 14.9 Gy was calculated. At these lethal doses, low density volume representing edema, demyelination, and necrosis had a similar response with an ED50 of 14.6 Gy. Radiation-induced decreases in white matter density appeared 5-6 months after sublethal doses (<14.3 Gy) and the volume of tissue characterized by this low density increased with time and dose. This sublethal low density change had an ED50 of 12.8 Gy, and may reflect a loss or generalized atrophy of glial cells and/or myelin. These results show that: (a) the dose response curves obtained after hemibrain x-irradiation are extremely steep; and (b) at least two processes may be involved in the development of late radiation damage, one that is rapid upon onset (a "delayed acute" reaction) and the other which is a slower and more degenerative process.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 63-70 |
| Number of pages | 8 |
| Journal | International Journal of Radiation Oncology, Biology, Physics |
| Volume | 14 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 1 1988 |
| Externally published | Yes |
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Keywords
- Computed tomography
- Dog
- Dose response
- Normal brain
- Radiation
ASJC Scopus subject areas
- Radiation
- Oncology
- Radiology Nuclear Medicine and imaging
- Cancer Research
Cite this
Radiation dose response of normal brain. / Fike, John R.; Cann, Christopher E.; Turowski, Krzysztof; Higgins, Robert; Chan, Albert S.L.; Phillips, Theodore L.; Davis, Richard L.
In: International Journal of Radiation Oncology, Biology, Physics, Vol. 14, No. 1, 01.01.1988, p. 63-70.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Radiation dose response of normal brain
AU - Fike, John R.
AU - Cann, Christopher E.
AU - Turowski, Krzysztof
AU - Higgins, Robert
AU - Chan, Albert S.L.
AU - Phillips, Theodore L.
AU - Davis, Richard L.
PY - 1988/1/1
Y1 - 1988/1/1
N2 - Dose response relationships were determined after hemibrain x-irradiation of normal beagle dogs. Radiation doses of 11.5, 13.5, 14.3, and 17 Gy were delivered in a single dose and results were compared to previous studies using doses of 15 and 30 Gy. Brain injury was quantified using computed tomography (CT), with serial studies obtained monthly up to 1 year following irradiation. Quantitative endpoints included low density volume and contrast enhancement. Doses above 14.3 Gy resulted in high lethality 5-8 months following irradiation, and an LD50 of 14.9 Gy was calculated. At these lethal doses, low density volume representing edema, demyelination, and necrosis had a similar response with an ED50 of 14.6 Gy. Radiation-induced decreases in white matter density appeared 5-6 months after sublethal doses (<14.3 Gy) and the volume of tissue characterized by this low density increased with time and dose. This sublethal low density change had an ED50 of 12.8 Gy, and may reflect a loss or generalized atrophy of glial cells and/or myelin. These results show that: (a) the dose response curves obtained after hemibrain x-irradiation are extremely steep; and (b) at least two processes may be involved in the development of late radiation damage, one that is rapid upon onset (a "delayed acute" reaction) and the other which is a slower and more degenerative process.
AB - Dose response relationships were determined after hemibrain x-irradiation of normal beagle dogs. Radiation doses of 11.5, 13.5, 14.3, and 17 Gy were delivered in a single dose and results were compared to previous studies using doses of 15 and 30 Gy. Brain injury was quantified using computed tomography (CT), with serial studies obtained monthly up to 1 year following irradiation. Quantitative endpoints included low density volume and contrast enhancement. Doses above 14.3 Gy resulted in high lethality 5-8 months following irradiation, and an LD50 of 14.9 Gy was calculated. At these lethal doses, low density volume representing edema, demyelination, and necrosis had a similar response with an ED50 of 14.6 Gy. Radiation-induced decreases in white matter density appeared 5-6 months after sublethal doses (<14.3 Gy) and the volume of tissue characterized by this low density increased with time and dose. This sublethal low density change had an ED50 of 12.8 Gy, and may reflect a loss or generalized atrophy of glial cells and/or myelin. These results show that: (a) the dose response curves obtained after hemibrain x-irradiation are extremely steep; and (b) at least two processes may be involved in the development of late radiation damage, one that is rapid upon onset (a "delayed acute" reaction) and the other which is a slower and more degenerative process.
KW - Computed tomography
KW - Dog
KW - Dose response
KW - Normal brain
KW - Radiation
UR - http://www.scopus.com/inward/record.url?scp=0023849576&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0023849576&partnerID=8YFLogxK
U2 - 10.1016/0360-3016(88)90052-1
DO - 10.1016/0360-3016(88)90052-1
M3 - Article
C2 - 3335464
AN - SCOPUS:0023849576
VL - 14
SP - 63
EP - 70
JO - International Journal of Radiation Oncology Biology Physics
JF - International Journal of Radiation Oncology Biology Physics
SN - 0360-3016
IS - 1
ER -