The appearance of irradiated areas throughout the 80-day period. The photographs are for five rats, one rat for each dose level. Each rat was wounded twice, once on the left side and once on the right side using the same dose. A. By day 9, erythema predominated within all irradiated areas. Crusting and desquamation were beginning to develop. Reactions intensified quickly, yet displayed a relatively uniform wound appearance across the entire dose range. Areas of increased reactivity were visible surrounding tattoo marks. B. By day 24, lower dose wounds (30.4 Gy and 41.5 Gy) each had a distinctly different appearance, while higher dose wounds (52.6 Gy to 76.5 Gy) exhibited features similar to other higher dose wounds. A 30.4 Gy wound had healed completely by day 20, accompanied by the return of hair growth in the irradiated area. Both 41.5 Gy wounds had undergone dry desquamation. Higher dose wounds displayed varying degrees of moist desquamation surrounded by intense crusting at the borders. C. By day 54, contraction in the 76.5 Gy wounds has significantly reduced the overall area of irradiated skin as well as the enclosed area of ulceration. A relatively low level of contraction was seen in the 65.5 Gy wounds. D. By day 80, contraction is apparent in the 65.5 Gy wounds, but impacts area and shape to a lesser degree than the higher dose. In the 76.5 Gy rat, contraction has distorted the irradiated area to such an extent that it has little resemblance to its original circular shape.