Datta R, Saha S
Med Phys. 1983 Mar-Apr;10(2):243-5. doi: 10.1118/1.595298.
A method has been developed for the quantitative determination of the tolerance doses for preoperative and postoperative radiotherapy of bones in New Zealand white rabbits. The midshaft osteotomy was carried out on both ulnae of each rabbit. Localized radiation of 2000, 3000, and 4000 rad (20, 30, and 40 Gy) was given in daily fractions of 500 rad to different groups of rabbits. The diaphyseal area of one forearm of each rabbit was irradiated and the other forearm was used as a control. After healing, the mechanical strength of each ulna was measured. The end point is defined as "strength reduction dose-63" (SRD63), i.e., the dose which would be expected to reduce the mechanical strength of the irradiated, fractured, and healed bone compared with the contralateral unirradiated diaphysis by 63%. The SRD63's for preoperative and postoperative radiotherapy were 4350 rad (43.5 Gy) and 6200 rad (62 Gy), respectively, with a 500 rad (5 Gy)/fraction schedule. Through the use of the nominal standard dose (NSD) formula at 300 rad (3 Gy)/fraction and five fraction per week, these SRD63's are equivalent to 5700 rad (57 Gy) and 8100 rad (81 Gy), respectively.
已开发出一种用于定量测定新西兰白兔骨骼术前和术后放疗耐受剂量的方法。对每只兔子的双侧尺骨进行中段截骨术。将不同组的兔子分别给予2000、3000和4000拉德（20、30和40戈瑞）的局部辐射，每天分次给予500拉德。对每只兔子一侧前臂的骨干区域进行照射，另一侧前臂用作对照。愈合后，测量每根尺骨的机械强度。终点定义为“强度降低剂量-63”（SRD63），即与对侧未照射的骨干相比，预期会使照射、骨折并愈合的骨骼机械强度降低63%的剂量。对于术前和术后放疗，在500拉德（5戈瑞）/分次方案下，SRD63分别为4350拉德（43.5戈瑞）和6200拉德（62戈瑞）。通过使用300拉德（3戈瑞）/分次、每周五次的标称标准剂量（NSD）公式，这些SRD63分别相当于5700拉德（57戈瑞）和8100拉德（81戈瑞）。
