Fuss M, Poljanc K, Hug E B
Department of Radiation Oncology, University of Heidelberg, Heidelberg, Germany.
Strahlenther Onkol. 2000 Dec;176(12):573-81. doi: 10.1007/pl00002327.
Neuropsychological impairment has been reported following whole brain and partial brain irradiation in children. The purpose of this analysis was to assess current knowledge, with focus on correlation with radiation dose, irradiated volume and age.
Full Scale IQ (FSIQ) data, representing 1,938 children, were derived from 36 publications and analyzed as to radiation dose, irradiated volume, and age.
FSIQ after whole brain irradiation showed a non-linear decline as dosage increased. The dose-effect relationship was age-related, with more pronounced FSIQ decline at younger age. FSIQ test results below the normal level (< 85) were found at doses higher than 24 and 36 Gy in children under age 3, and older than age 6, respectively. Mean FSIQ test result after 18 Gy was 100, thus at the mean standard value; a minor decline was detectable only when compared to test results of a control group. Young children scored at this dose in the low normal range. Partial brain irradiation caused minor FSIQ decline, with measurable effects at dose levels > 50 Gy.
The collected data suggest that whole brain irradiation doses of 18 and 24 Gy have no major impact on intellectual outcome in children older than age 6, but may cause impairment in younger children. Doses > 24 Gy comprise a substantial risk for FSIQ decline, even in older children. At equal dose levels, partial brain irradiation is less damaging than whole brain irradiation. The authors are well aware of limitations in the interpretation of data collected for the current review. Thus, further research is required to evaluate the effect of low-dose whole brain irradiation as well as partial brain irradiation on FSIQ development.
已有报道称儿童接受全脑和部分脑照射后会出现神经心理损伤。本分析的目的是评估当前的相关知识，重点关注与辐射剂量、照射体积和年龄的相关性。
从36篇出版物中获取了代表1938名儿童的全量表智商（FSIQ）数据，并对辐射剂量、照射体积和年龄进行了分析。
全脑照射后的FSIQ随着剂量增加呈非线性下降。剂量效应关系与年龄相关，年龄越小，FSIQ下降越明显。分别在3岁以下和6岁以上儿童中，当剂量高于24 Gy和36 Gy时，发现FSIQ测试结果低于正常水平（<85）。18 Gy照射后的平均FSIQ测试结果为100，处于平均标准值；只有与对照组的测试结果相比时，才能检测到轻微下降。年幼儿童在此剂量下得分处于低正常范围。部分脑照射导致FSIQ轻微下降，在剂量水平>50 Gy时可检测到明显影响。
收集的数据表明，18 Gy和24 Gy的全脑照射剂量对6岁以上儿童的智力结果没有重大影响，但可能会对年幼儿童造成损害。即使对于年龄较大的儿童，>24 Gy的剂量也存在FSIQ下降的重大风险。在相同剂量水平下，部分脑照射比全脑照射的损害性小。作者充分意识到本次综述所收集数据解释方面的局限性。因此，需要进一步研究来评估低剂量全脑照射以及部分脑照射对FSIQ发育的影响。
