Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California.
Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut.
J Nucl Med. 2021 Jan;62(1):43-47. doi: 10.2967/jnumed.120.243139. Epub 2020 May 15.
The metaiodobenzylguanidine (MIBG) scan is one of the most sensitive noninvasive lesion detection modalities for neuroblastoma. Unlike I-MIBG, I-MIBG allows high-resolution PET. We evaluated I-MIBG PET/CT for its diagnostic performance as directly compared with paired I-MIBG scans. Before I-MIBG therapy, standard I-MIBG imaging (5.2 MBq/kg) was performed on 7 patients, including whole-body (anterior-posterior) planar imaging, focused-field-of-view SPECT/CT, and whole-body I-MIBG PET/CT (1.05 MBq/kg). After therapy, 2 of 7 patients also completed I-MIBG PET/CT as well as paired I-MIBG planar imaging and SPECT/CT. One patient underwent I-MIBG PET/CT only after therapy. We evaluated all 8 patients who showed at least 1 I-MIBG-positive lesion with a total of 10 scans. In 8 pairs, I-MIBG and I-MIBG were performed within 1 mo of each other. The locations of identified lesions, the number of total lesions, and the curie scores were recorded for the I-MIBG and I-MIBG scans. Finally, for 5 patients who completed at least 3 PET/CT scans after administration of I-MIBG, we estimated the effective dose of I-MIBG. I-MIBG whole-body planar scans, focused-field-of-view SPECT/CT scans, and whole-body I-MIBG PET scans found 25, 32, and 87 total lesions, respectively. There was a statistically significant difference in lesion detection for I-MIBG PET/CT versus I-MIBG planar imaging ( < 0.0001) and I-MIBG SPECT/CT ( < 0.0001). The curie scores were also higher for I-MIBG PET/CT than for I-MIBG planar imaging and SPECT/CT in 6 of 10 patients. I-MIBG PET/CT demonstrated better detection of lesions throughout the body, including the chest, spine, head and neck, and extremities. The effective dose estimated for patient-specific I-MIBG was approximately 10 times that of I-MIBG; however, given that we administered a very low activity of I-MIBG (1.05 MBq/kg), the effective dose was only approximately twice that of I-MIBG despite the large difference in half-lives (100 vs. 13.2 h). The first-in-humans use of low-dose I-MIBG PET for monitoring disease burden demonstrated tumor detection capability superior to that of I-MIBG planar imaging and SPECT/CT.
间碘苄胍（MIBG）扫描是神经母细胞瘤最敏感的非侵入性病变检测方法之一。与 I-MIBG 不同，I-MIBG 允许进行高分辨率 PET。我们评估了 I-MIBG PET/CT 的诊断性能，将其与配对的 I-MIBG 扫描进行了直接比较。在 I-MIBG 治疗前，对 7 名患者进行了标准 I-MIBG 成像（5.2 MBq/kg），包括全身（前后）平面成像、焦点视野 SPECT/CT 和全身 I-MIBG PET/CT（1.05 MBq/kg）。治疗后，7 名患者中有 2 名还完成了 I-MIBG PET/CT 以及配对的 I-MIBG 平面成像和 SPECT/CT。1 名患者仅在治疗后进行了 I-MIBG PET/CT。我们评估了所有 8 名至少有 1 个 I-MIBG 阳性病变的患者，这些患者共有 10 个扫描。在 8 对中，I-MIBG 和 I-MIBG 在彼此 1 个月内进行。记录 I-MIBG 和 I-MIBG 扫描的病变位置、总病变数量和居里分数。最后，对于 5 名至少在 I-MIBG 给药后完成 3 次 PET/CT 扫描的患者，我们估计了 I-MIBG 的有效剂量。I-MIBG 全身平面扫描、焦点视野 SPECT/CT 扫描和全身 I-MIBG PET 扫描分别发现 25、32 和 87 个总病变。I-MIBG PET/CT 与 I-MIBG 平面成像（<0.0001）和 I-MIBG SPECT/CT（<0.0001）在病变检测方面存在统计学显著差异。在 10 名患者中的 6 名中，I-MIBG PET/CT 的居里分数也高于 I-MIBG 平面成像和 SPECT/CT。I-MIBG PET/CT 能够更好地检测全身各部位的病变，包括胸部、脊柱、头颈部和四肢。为特定患者估计的 I-MIBG 有效剂量约为 I-MIBG 的 10 倍；然而，由于我们给予了非常低剂量的 I-MIBG（1.05 MBq/kg），尽管半衰期差异很大（100 对 13.2 小时），有效剂量仍仅为 I-MIBG 的两倍左右。I-MIBG 的首次在人体中使用低剂量 I-MIBG PET 监测疾病负担，显示出优于 I-MIBG 平面成像和 SPECT/CT 的肿瘤检测能力。
