Taal B G, Hoefnagel C, Boot H, Valdés Olmos R, Rutgers M
Department of Gastroenterology, Netherlands Cancer Institute/Antoni van Leeuwenhoek Ziekenhuis, Amsterdam.
Ann Oncol. 2000 Nov;11(11):1437-43. doi: 10.1023/a:1026592025862.
131I-meta-iodobenzylguanidine (MIBG) has been used with success for the palliation of metastatic carcinoid. To qualify more patients for this treatment, we evaluated the effect of predosing with non-radiolabeled MIBG on 131I-MIBG tumour targeting in carcinoid patients and in mice with BON human carcinoid xenografts.
Ten carcinoid patients with a faint tumour imaging on a diagnostic 131I-MIBG scan (1 mCi = 37 MBq, 5 mg MIBG) received non-radiolabeled MIBG prior to a second scintigraphy. In case of improved tumour targeting patients were treated with 200 mCi (7.4 GBq) 131I-MIBG following a pharmacological predose of 20-40 mg/m2 MIBG.
In six patients. highly increased 'tumour/non-tumour' ratios were seen due to reduced levels in normal tissues and increased tumour accumulation. The combined treatment applied in five patients, considerably improved symptoms in all (duration 6-12 months), accompanied by biochemical response in three. In BON carcinoid xenografted mice, MIBG was injected intraperitoneally followed by intravenous 125I-MIBG with similar findings: increased 'tumour/non-tumour' radioactivity ratios by 1.5-3-fold.
Predosing with non-radiolabeled MIBG resulted in improved 131I-MIBG tumour targeting, prolonged palliation and encouragingly often biochemical responses in carcinoid.
131I-间碘苄胍（MIBG）已成功用于缓解转移性类癌。为了使更多患者适合这种治疗，我们评估了预先给予非放射性标记的MIBG对类癌患者和携带BON人源类癌异种移植瘤的小鼠中131I-MIBG肿瘤靶向性的影响。
10名在诊断性131I-MIBG扫描（1毫居里 = 37兆贝可，5毫克MIBG）时肿瘤显像模糊的类癌患者在第二次闪烁扫描前接受了非放射性标记的MIBG。如果肿瘤靶向性改善，患者在给予20 - 40毫克/平方米MIBG的药理预给药后，接受200毫居里（7.4吉贝可）的131I-MIBG治疗。
6名患者中，由于正常组织中的水平降低和肿瘤摄取增加，“肿瘤/非肿瘤”比值显著升高。5名患者接受的联合治疗使所有患者的症状得到显著改善（持续时间6 - 12个月），3名患者出现生化反应。在携带BON类癌异种移植瘤的小鼠中，腹腔注射MIBG，随后静脉注射125I-MIBG，也有类似发现：“肿瘤/非肿瘤”放射性比值增加1.5 - 3倍。
预先给予非放射性标记的MIBG可改善131I-MIBG的肿瘤靶向性，延长缓解期，并且在类癌患者中常常令人鼓舞地出现生化反应。
