甲状腺显像归一化分析在^131I治疗Graves甲亢中的价值

Value of normalization analysis of thyroid scans on 131I treatment planning for Graves＇ disease

目的探讨计算机辅助的甲状腺显像归一化分析在131I治疗Graves甲状腺功能亢进症（简称甲亢）中的作用。方法回顾分析^131I治疗的Graves甲亢患者60例，以甲状腺小于35g且没有结节为人组标准。重新调取甲状腺扫描的原始数据，经计算机软件行归一化处理和图像放大。对甲状腺两叶面积比值、放射性计数比值、灰阶比值、呈多中心放射性分布的例数、用药次数和总治疗剂量进行多重线性回归分析（逐步回归法），研究总治疗剂量和用药次数与性别、年龄及上述因素的相关性，并根据临床转归进行分组，分析转归为甲状腺功能（简称甲功）正常和甲功减退（简称甲减）与上述因素的相关性。结果根据Marinelli公式计算的131I剂量，单次给药甲亢治愈率50％（30／60），其余患者需要多次给药治疗。除了甲状腺质量和摄碘率外，^131I总剂量还和女性（F=4．23，P=0．050）、两叶面积比（F=6．20，P=0．020）、多中心放射性分布（F=5．12，P=0．033）有关。131I治疗次数与两叶灰阶比（F=8．89，P=0．006）和多中心放射性分布（F=4．98，P=n034）有关。转归为甲功正常组服药剂量与两叶灰阶比（F=10．66，P=0．017）和面积比（F=10．42，P=0．018）相关；而转归为甲减组的影响因素为甲状腺质量（F=7．65，P=0．013）和多中心放射性分布（F=8．01，P=0．011）。结论计算机辅助归一化分析对Graves甲亢治疗计划的制定和预后有一定帮助，对于出现明显的甲状腺两叶放射性分布不均者，应增加剂量和多次治疗；对于放射性分布均匀者，应注意避免剂量增大与甲状腺质量增大呈线性关系，否则甲减概率会增高。

Objective To explore the value of normalization analysis of thyroid scans on 131I treat- ment planning for Graves＇ disease. Methods Patients with hyperthyroidism treated by 131I were retrospec- tively analyzed. Sixty cases with thyroid glands less than 35 g and without thyroid nodules were enrolled. Raw data of thyroid scans were re-processed using a software for normalization and magnification. Correlation between total dose, the number of treatments and other factors, such as area ratios of bilateral lobes, bilat- eral radioactive counts, bilateral gray scales and muhifocal uptake patterns, were analyzed using step-by- step regression analysis. Correlations between normal thyroid function, hypothyroidism and the abovemen- tioned factors were analyzed using multiple linear regression analysis. Results Fifty percent （30/60） of cases were cured after a single-dose treatment, and the remaining 50% required multiple treatments. In ad- dition to thyroid mass and radioactive iodine uptake, total close correlated with gender （ F = 4.23, P = 0. 050 ）, area ratio of bilateral lobes （ F = 6.20, P = 0. 020） and multifocal uptake pattern （ F = 5.12, P = 0. 033 ）. The number of treatments correlated with ratio of bilateral gray scales （ F = 8.89, P = 0. 006 ） and multifocal uptake pattern （ F = 4.98, P = 0. 034）. According to outcomes, patients were divided into a nor- mal thyroid function group and a hypothyroidism group. 131I dose correlated with the area ratio of bilateral lobes （F = 10.42, P = 0.018 ） and ratio of bilateral gray scales in the normal thyroid function group （F = 10.66, P = 0. 017） ; whereas in the hypothyroidism group, the clinical outcome correlated with thyroid mass （ F = 7.65, P = 0,013） and multifocal uptake pattern （ F = 8.01, P = 0.011 ）. Conclusions Computer- aided normalization analysis is useful for 131I dose calculation in the treatment of hyperthyroidism. For pa- tients with significantly unbalanced bilateral radiotracer distribution, increasing the dose and the number of treatments should be suggested. For patients with homogeneous radiotracer distribution, a linear method of dose increment according to the thyroid mass should be avoided to reduce the rate of hypothyroidism.