Yamamoto Y, Nishiyama Y, Toyama Y, Kunishio K, Satoh K, Ohkawa M
Department of Radiology, Faculty of Medicine, Kagawa Medical University, Kagawa, Japan.
Nucl Med Commun. 2002 Dec;23(12):1183-90. doi: 10.1097/00006231-200212000-00006.
The purpose of this study was to evaluate whether Tc-hexakis-2-methoxyisobutylisonitrile ( Tc-MIBI) or Tl single photon emission tomography (SPET) could detect recurrent tumours in patients with previous radiation therapy for brain tumours. Dual SPET with Tc-MIBI and Tl was performed in 21 patients suspected of having recurrent brain tumours. SPET images were acquired 15 min (early) and 2 h (delayed) after injection. The ratio of the average counts for the region of interest in the lesion area and its mirror image in normal brain tissue was obtained. Early and delayed ratios were calculated. On the basis of histological and/or clinical findings, the final diagnosis was considered as recurrent tumours in 15 patients and radiation necrosis in six. Both ratios using Tc-MIBI and Tl were significantly higher in recurrent tumours than in radiation necrosis. Based on a cut-off of 5.89 of the early ratio using Tc-MIBI to distinguish between recurrent tumours and radiation necrosis, the accuracy was 90%. Based on a cut-off of 6.77 of the delayed ratio using Tc-MIBI, the accuracy was 86%. The corresponding values using cut-offs of 2.40 and 1.85 with Tl were 90% and 86%, respectively. However, within recurrent tumours, both ratios for Tc-MIBI were significantly higher than those for Tl. Early Tc-MIBI SPET may be especially useful for the detection of recurrent tumours in patients who have previously undergone radiation therapy for brain tumours.
本研究的目的是评估锝-六甲基异丁基异腈（Tc-MIBI）或铊单光子发射断层扫描（SPET）能否检测出曾接受过脑肿瘤放射治疗患者的复发性肿瘤。对21例疑似患有复发性脑肿瘤的患者进行了Tc-MIBI和铊的双SPET检查。注射后15分钟（早期）和2小时（延迟期）采集SPET图像。获取病变区域及其在正常脑组织中镜像区域的平均计数比值。计算早期和延迟比值。根据组织学和/或临床结果，最终诊断为15例复发性肿瘤和6例放射性坏死。复发性肿瘤中使用Tc-MIBI和铊的两种比值均显著高于放射性坏死。以Tc-MIBI早期比值5.89作为区分复发性肿瘤和放射性坏死的临界值，准确率为90%。以Tc-MIBI延迟比值6.77作为临界值，准确率为86%。铊的临界值分别为2.40和1.85时，相应的准确率分别为90%和86%。然而，在复发性肿瘤中，Tc-MIBI的两种比值均显著高于铊。早期Tc-MIBI SPET对于检测曾接受过脑肿瘤放射治疗患者的复发性肿瘤可能特别有用。
