目的利用99mTc-DTPASPECT在全脑放疗过程中研究脑转移瘤血-脑屏障变化规律,为放疗疗效预测和化疗的适时介入提供影像学依据。方法19例60Coγ线全脑外照射的脑转移瘤患者,在放疗前、中(20Gy)、后行99mTc-DTPA核素脑断层显像,分别计算放疗前、中时的肿瘤区与对侧正常脑组织区放射性计数比值(T/N)值。结果1)放疗前、中32枚脑转移瘤T/N值分别为1.892±1.094和2.167±1.637(P<0.05);2)T/N升高组和不升高组中的脑转移瘤在放疗后有效率分别为94.1%(16/17)和46.7%(7/15)(P<0.05)。结论在全脑放疗20Gy时,脑转移瘤的血-脑脊液屏障开放程度要高于正常脑组织,T/N值升高,预示放疗效果佳。 Objective To study the changes of blood-brain barrier in brain metastases by 99mTc-DTPASPECT in the course of whole brain radiotherapy and provide imaging evidence for the prediction of radiotherapy efficacy and timely intervention of chemotherapy. Methods Twenty-nine patients with brain metastases of 60Coγ-ray whole brain irradiation were treated with 99mTc-DTPA nuclide scintigraphy before and after radiotherapy (20Gy), and the tumor area and contralateral normal before and after radiotherapy Brain Tissue Area Radioactive Count Ratio (T / N) Value. Results 1) The T / N values ​​of 32 brain metastases before and after radiotherapy were 1.892 ± 1.094 and 2.167 ± 1.637 respectively (P <0.05); 2) The brain metastases in T / N elevated group and non- The effective rates after radiotherapy were 94.1% (16/17) and 46.7% (7/15), respectively (P <0.05). Conclusions At 20 Gy of whole brain irradiation, the blood-brain barrier of brain metastases is higher than that of normal brain tissue, and the T / N value is increased, which indicates that radiotherapy is effective.