Radiobiology 2016

Segment of mouse intestine irradiated with varying doses

XRT

a

b

c d

12.5Gy

14.0Gy

15.5Gy

17.0Gy

Day 13 Overt tissue response (e.g. ulceration) is dose-dependent with a threshold followed by a rapid increase in severity. a. Patchy breakdown of mucosa except in shielded mucosa at top of specimen. b. Ulcerated mucosa being resurfaced by near-confluent nodules regenerated from a large number of independently surviving jejunal clonogens. c. Severe ulceration but with about 60 discrete clonogen-derived mucosal nodules. d. As for c. but only 4 regenerated nodules.