Department of Neurosurgery, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma, 371-8511, Japan.
Department of Diagnostic Radiology and Nuclear Medicine, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
Int J Clin Oncol. 2022 Aug;27(8):1264-1272. doi: 10.1007/s10147-022-02171-3. Epub 2022 May 13.
Preoperative differential diagnosis between primary central nervous system lymphoma (PCNSL) and glioblastoma (GBM) is important because these tumors require different surgical strategies. This study investigated the usefulness of dual isotope, iodine-123-labeled N-isopropyl-p-iodo-amphetamine (I-IMP) and thallium-201 chloride single-photon emission computed tomography (Tl SPECT) for the differential diagnosis.
Twenty-five PCNSL patients and 27 GBM patients who underwent dual isotope imaging, I-IMP and Tl SPECT, are included. Tumor-to-normal (T/N) ratio was calculated from the ratio of maximum tracer counts in the lesion to the mean counts in the contralateral cerebral cortex. The mean and minimum apparent diffusion coefficient values (ADC and ADC respectively) on magnetic resonance imaging were also analyzed.
Delayed phase I-IMP SPECT was the most useful imaging examination for the differentiation between PCNSL and GBM compared with early phase I-IMP SPECT, early and delayed phase Tl SPECT, ADC, and ADC. However, the median T/N ratios of PCNSL and GBM were 1.32 and 0.83, respectively, in the delayed phase I-IMP SPECT. On the other hand, the median T/N ratios of PCNSL and GBM were 3.10 and 2.34, respectively, in the delayed phase Tl SPECT, with excellent tumor detection.
Delayed phase I-IMP SPECT could differentiate between PCNSL and GBM with high accuracy, but T/N ratio was low and tumor detection was poor. Tl SPECT was useful for estimation of the malignancy and localization of the tumors with high T/N ratio. Dual isotope I-IMP and Tl SPECT was useful for the preoperative diagnosis of PCNSL and GBM.
原发性中枢神经系统淋巴瘤（PCNSL）和胶质母细胞瘤（GBM）的术前鉴别诊断很重要，因为这两种肿瘤需要不同的手术策略。本研究探讨了碘-123-标记 N-异丙基-p-碘-安非他命（I-IMP）和铊-201 氯化物单光子发射计算机断层扫描（Tl SPECT）双同位素显像在鉴别诊断中的作用。
共纳入 25 例 PCNSL 患者和 27 例 GBM 患者，行双同位素成像、I-IMP 和 Tl SPECT 检查。肿瘤与正常组织（T/N）比值通过病变部位最大示踪剂计数与对侧大脑皮质平均计数的比值计算。还分析了磁共振成像上的平均和最小表观扩散系数值（ADC 和 ADC 分别）。
与早期 I-IMP SPECT、早期和延迟期 Tl SPECT、ADC 和 ADC 相比，延迟期 I-IMP SPECT 是鉴别 PCNSL 和 GBM 最有用的影像学检查。然而，PCNSL 和 GBM 患者延迟期 I-IMP SPECT 的 T/N 比值中位数分别为 1.32 和 0.83。另一方面，PCNSL 和 GBM 患者延迟期 Tl SPECT 的 T/N 比值中位数分别为 3.10 和 2.34，肿瘤检出率高。
延迟期 I-IMP SPECT 可以准确地区分 PCNSL 和 GBM，但 T/N 比值较低，肿瘤检出率较差。Tl SPECT 可用于估计肿瘤的恶性程度和定位，具有较高的 T/N 比值。双同位素 I-IMP 和 Tl SPECT 可用于 PCNSL 和 GBM 的术前诊断。
