Hopewell J W, Young C M
Br J Radiol. 1982 May;55(653):356-61. doi: 10.1259/0007-1285-55-653-356.
The importance of the size of the treatment area for the response of the skin to radiation has been studied in the pig. The responses of skin areas of 16 cm3 (4 x 4 cm) and 64 cm2 (16 x 4 cm) were compared after single doses of X rays. In the initial 3-9-week period after irradiation the severity of the erythema reaction, which is associated with epidermal call death, was not influenced by the area of skin irradiated. For the later dermal response (10-16 weeks) a similar result was obtained. The dose required to produce dermal necrosis in 50% of the fields treated (ED50) was approximately 2070 cGy for both field sizes. Additional studies have shown that the ED50 for dermal necrosis was not influenced by the age of animals at the time of irradiation. This was despite considerable differences in the vascular density and blood flow in pig skin with increasing age. The apparent contradiction between the results of this experimental study in the pig, which shows no effect of field size, and currently accepted clinical practice is discussed.
在猪身上研究了治疗区域大小对皮肤辐射反应的重要性。比较了单次X射线照射后16平方厘米（4×4厘米）和64平方厘米（16×4厘米）皮肤区域的反应。在照射后的最初3至9周内，与表皮细胞死亡相关的红斑反应严重程度不受照射皮肤面积的影响。对于后期的真皮反应（10至16周），也得到了类似的结果。两种照射野大小在50%的治疗野中产生真皮坏死所需的剂量（ED50）约为2070厘戈瑞。进一步的研究表明，真皮坏死的ED50不受照射时动物年龄的影响。尽管随着年龄增长猪皮肤的血管密度和血流量存在显著差异，但仍是如此。讨论了猪的这项实验研究结果（显示照射野大小无影响）与目前公认的临床实践之间明显的矛盾。
