Egawa S, Tsukiyama I, Akine Y, Kajiura Y, Ogino T
Department of Radiation Therapy, National Cancer Center Hospital, Tokyo, Japan.
Radiat Med. 1987 Nov-Dec;5(6):207-11.
Suppression of the growth of orbit and skull in 13 retinoblastoma patients treated by radiotherapy was investigated. The age of patients at the time of treatment ranged from 1 month to 6 years and 11 months. They were examined after three to 18 years. Suppression of the growth in involved areas and other parts of the skull within the beam of radiation were estimated by inspection, X-ray findings, and X-CT examinations. The involved orbit received more than 32 Gy, and the suppression of bone growth was prominent. At the opposite temporal bone, suppression of growth was prominent in eight cases out of 11, in these cases, the radiation dose was at least 14 Gy. Two cases, in whom the radiation dose was less than 12.6 Gy, have not shown any suppression of bony growth. Results were also obtained for a nominal single dose (ret). In all cases of more than 1,000 ret, suppression was prominent, but at less than 1,000 ret, four out of nine cases, and at less than 600 ret, two out of four cases showed suppression of bony growth. If the safety dose to avoid the suppression of bony growth is 400 ret, this is equivalent to three times the radiation dose of 200 cGy. In conclusion, the suppression of bony growth of the orbit and temporal area of the skull of young patients is caused by very small doses of radiation.
对13例接受放射治疗的视网膜母细胞瘤患者眼眶和颅骨生长受抑制情况进行了研究。治疗时患者年龄为1个月至6岁11个月。在治疗后3至18年对他们进行了检查。通过视诊、X线检查和X线计算机断层扫描（X-CT）检查评估放射野内受累区域及颅骨其他部位的生长受抑制情况。受累眼眶接受的辐射剂量超过32 Gy，骨生长受抑制明显。在对侧颞骨，11例中有8例生长受抑制明显，这些病例的辐射剂量至少为14 Gy。2例辐射剂量小于12.6 Gy的患者未显示任何骨生长受抑制情况。还得出了名义单次剂量（ret）的结果。在所有超过1000 ret的病例中，生长受抑制明显，但在小于1000 ret的病例中，9例中有4例，在小于600 ret的病例中，4例中有2例显示骨生长受抑制。如果避免骨生长受抑制的安全剂量为400 ret，这相当于200 cGy辐射剂量的三倍。总之，小剂量辐射即可导致年轻患者眼眶和颅骨颞部区域的骨生长受抑制。
