The use of three-dimensional treatment planning and volume-reduction techniques in radiotherapy has prompted the development of a number of mathematical models to describe the effect of changing treatment volume on the probability of associated complications in normal tissues. However, limited data are available to test or support these models. One prediction of the Probability model and analogous models, which describe the volume-effect relationship for late end points in tissues with a series-type arrangement of functional subunits, is that there is no threshold volume in the development of the end point. This hypothesis was tested in mouse colorectum, a normal tissue with functional subunits suggested to be arranged in series, using the incidence of obstructions due to consequential fibrosis as the end point of damage. Various lengths of the colorectum of C3Hf/Kam mice were irradiated with single doses of 250 kVp X rays. A threshold length between 10 and 15 mm was observed after 32 Gy. The Probability model could not describe the data adequately, but a modified version that included a threshold volume term (the Threshold Probability model) provided an excellent fit. In a separate experiment, epithelial regeneration (migration, extracryptal proliferation and formation of new crypts) was examined as a possible mechanism for the threshold length. Reepithelialization was complete after 32 Gy was delivered to lengths below (5 or 10 mm) but not above (20 mm) the threshold for consequential obstruction. Proliferation of epithelial cells outside the crypt on the mucosal surface (i.e. extracryptal proliferation) may contribute to the regeneration process. The data indicate that regeneration of the epithelium after irradiation results in a threshold length of the colorectum in the development of consequential fibrosis, in contradiction to predictions of the Probability model.
Skip Nav Destination
Research Article| January 01 1998
Volume Effects and Epithelial Regeneration in Irradiated Mouse Colorectum
Radiat Res (1998) 149 (1): 1–10.
- Views Icon Views
- Share Icon Share
- Search Site
Mark W. Skwarchuk, Elizabeth L. Travis; Volume Effects and Epithelial Regeneration in Irradiated Mouse Colorectum. Radiat Res 1 January 1998; 149 (1): 1–10. doi: https://doi.org/10.2307/3579675
Download citation file:
Citing articles via
Commonalities Between COVID-19 and Radiation Injury
Carmen I. Rios, David R. Cassatt, Brynn A. Hollingsworth, Merriline M. Satyamitra, Yeabsera S. Tadesse, Lanyn P. Taliaferro, Thomas A. Winters, Andrea L. DiCarlo
Low-Dose Radiation Therapy (LDRT) for COVID-19: Benefits or Risks?
Pataje G. Prasanna, Gayle E. Woloschak, Andrea L. DiCarlo, Jeffrey C. Buchsbaum, Dörthe Schaue, Arnab Chakravarti, Francis A. Cucinotta, Silvia C. Formenti, Chandan Guha, Dale J. Hu, Mohammad K. Khan, David G. Kirsch, Sunil Krishnan, Wolfgang W. Leitner, Brian Marples, William McBride, Minesh P. Mehta, Shahin Rafii, Elad Sharon, Julie M. Sullivan, Ralph R. Weichselbaum, Mansoor M. Ahmed, Bhadrasain Vikram, C. Norman Coleman, Kathryn D. Held
Photon GRID Radiation Therapy: A Physics and Dosimetry White Paper from the Radiosurgery Society (RSS) GRID/LATTICE, Microbeam and FLASH Radiotherapy Working Group
Hualin Zhang, Xiaodong Wu, Xin Zhang, Sha X. Chang, Ali Megooni, Eric D. Donnelly, Mansoor M. Ahmed, Robert J. Griffin, James S. Welsh, Charles B. Simone, II, Nina A. Mayr
Germicidal Efficacy and Mammalian Skin Safety of 222-nm UV Light
Manuela Buonanno, Brian Ponnaiya, David Welch, Milda Stanislauskas, Gerhard Randers-Pehrson, Lubomir Smilenov, Franklin D. Lowy, David M. Owens, David J. Brenner