Fractionated Irradiation Augments Inter-Strain Variation of Skin Reactions among Three Strains of Mice

Abstract

The multifraction regimens commonly used in conventional clinical radiotherapy are largely based on radiobiological experiments. However, no experimental reports on skin reactions focusing on inter-strain differences have displayed clinical relevance to the fractionated dose schedule. In this study, mice of inbred strains A/J, C57BL/6J, and C3H/HeMs were used to reveal inter-strain difference after multifractionated irradiation. Irradiation was performed daily at graded doses of 30-60 Gy total doses, with 10 fractions of 3-6 Gy. Acute skin reactions following irradiation were scored for 50 days after irradiation. Dividing a dose into a number of fractions obviously spared skin damage in the three strains of mice. No mouse exhibited a skin damage score more than 1.5, while single dose irradiation resulted in skin damage scores up to 3. The three different strains, however, showed varying susceptibility to fractionated irradiation within the range under 1.5. C3H/HeMs did not display any skin reaction after irradiation with 40 Gy total dose, while C57BL/6J and A/J demonstrated various skin reactions. Different latent periods of damage were also observed among the strains after irradiation at each dose. Our data suggest that genetic factors cause obvious variations in severity of damage and latent period after fractionated irradiation.

T cell tolerance to the skin: a central role for central tolerance

“…They are therefore likely to be lymph node-resident melanocyte not fully differentiated to produce pigment such as those in the skin. Our observation is consistent with the fact that melanocytes resist irradiation (p. 517 of [36]). The presence of melanocyte in lymph nodes has already been pointed out in the case of nevi observed in this organ.…”

Relative Biological Effectiveness of Carbon Ions for Local Tumor Control of a Radioresistant Prostate Carcinoma in the Rat

“…Dry and moist desquamation of the skin (#1.5 + according to the normal damage scale previously published [39]) occurred as the most prominent side effect, which disappeared within 4-6 weeks after therapy. Radiation-induced side effects in the normal skin around the tumor were worse in animals in which proliferative activity was not controlled, presumably because skin recovery was constraint during increased volumetric tumor expansion.…”

IL-1 Generated Subsequent to Radiation-Induced Tissue Injury Contributes to the Pathogenesis of Radiodermatitis

“…Based on these results, we selected single-fraction doses of either 20 or 21.75 Gy for subsequent experiments; the different doses were two variations used by different personnel and similar results were obtained at both doses. The skin was evaluated over time using a scoring system similar to that used by others previously (23) as follows: (0) normal, (1) erythema, (2) dry desquamation, (3) wet desquamation, and (4) ulceration (Fig. 2).…”