TY - JOUR
T1 - Multifraction radiation response of mouse lung
AU - Vegesna, V.
AU - Withers, H. Rodney
AU - Thames, Howard D.
AU - Mason, Kathy
N1 - Funding Information:
This investigation was supported by PHS Grant Numbers CA-31612 and CA-29026 awarded by the National Cancer Institute, DHHS. The authors thank Betty O. Reid for expert technical assistance, Dr J. C. Kern and his staff for care of the animals and Dr J. B. Smathers for dosimetry. We wish also to thank Jan Haas for typing this manuscript and Cally Davis for preparing the figures.
PY - 1985/4/1
Y1 - 1985/4/1
N2 - The response of mouse lung to repeated doses of 60 Co and110 -rays of as low as 115 cGy per fraction was measured using death from pneumonitis between 80 and 120 days after irradiation as the endpoint. A fractionation interval of 3 h was maintained for most regimens but in the longer experiments some 12 h intervals were introduced for logistic reasons. The longest overall duration (for a 43 fraction regimen) was 8 days. The total doses required to produce 50 per cent mortality increased continuously as dose/fraction was decreased, even from 160 to 115 cGy per fraction. Of clinical relevance, the steepness of the isoeffect curve over the dose range 115-500 cGy indicates that the lung shows greater sparing from dose fractionation than is characteristic of more rapidly-responding normal tissues, resembling, in this respect, other more slowly-responding tissues such as spinal cord. The plot of the reciprocal of the LD 50 values as a function of dose per fraction was non-linear, suggesting that a linear quadratic dose response model may not be appropriate or that repair of cellular injury in lung is not complete in 3 h, or both.
AB - The response of mouse lung to repeated doses of 60 Co and110 -rays of as low as 115 cGy per fraction was measured using death from pneumonitis between 80 and 120 days after irradiation as the endpoint. A fractionation interval of 3 h was maintained for most regimens but in the longer experiments some 12 h intervals were introduced for logistic reasons. The longest overall duration (for a 43 fraction regimen) was 8 days. The total doses required to produce 50 per cent mortality increased continuously as dose/fraction was decreased, even from 160 to 115 cGy per fraction. Of clinical relevance, the steepness of the isoeffect curve over the dose range 115-500 cGy indicates that the lung shows greater sparing from dose fractionation than is characteristic of more rapidly-responding normal tissues, resembling, in this respect, other more slowly-responding tissues such as spinal cord. The plot of the reciprocal of the LD 50 values as a function of dose per fraction was non-linear, suggesting that a linear quadratic dose response model may not be appropriate or that repair of cellular injury in lung is not complete in 3 h, or both.
KW - Lung Ld50
UR - http://www.scopus.com/inward/record.url?scp=0021984007&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0021984007&partnerID=8YFLogxK
U2 - 10.3109/rab.47.4.413
DO - 10.3109/rab.47.4.413
M3 - Article
C2 - 3872854
AN - SCOPUS:0021984007
SN - 0955-3002
VL - 47
SP - 413
EP - 422
JO - International journal of radiation biology
JF - International journal of radiation biology
IS - 4
ER -