No-carrier-added I-123-MIBG: An initial clinical study in patients with phaeochromocytoma

Citation
J. Owens et al., No-carrier-added I-123-MIBG: An initial clinical study in patients with phaeochromocytoma, NUCL MED C, 21(5), 2000, pp. 437-440
Citations number
10
Categorie Soggetti
Radiology ,Nuclear Medicine & Imaging
Journal title
NUCLEAR MEDICINE COMMUNICATIONS
ISSN journal
01433636 → ACNP
Volume
21
Issue
5
Year of publication
2000
Pages
437 - 440
Database
ISI
SICI code
0143-3636(200005)21:5<437:NIAICS>2.0.ZU;2-T
Abstract
Radioiodinated meta-iodobenzylguanidine (MIBG) is used routinely for imagin g and targeted radiotherapy of tumours derived from the neural crest. Since active uptake of MIBG by the noradrenaline transporter (NAT) makes a great er contribution to total drug accumulation than passive uptake when MIBG is present at low concentrations, tumour-specific uptake should be enhanced b y the administration of lower molar amounts of MIBG. This could be achieved through the use of MIBG with a high specific activity. Commercially availa ble preparations of I-123-MIBG have specific activities of approximately 20 0 MBq.mg(-1). We have synthesized and used no-carrier-added (n.c.a.) I-123- MIBG produced by an iododesilylation reaction (specific activity 0.7 TBq.mg (-1)). We report here the first clinical studies comparing the commercially available and n.c.a. MIBG diagnostic preparations. Five patients with know n phaeochromocytoma were studied. Unlike studies in animal models, no consi stent improvement in tumour uptake was observed with the n.c.a. material. A larger patient group is required to determine whether there are significan t differences between the two preparations, before proceeding to studies at therapeutic activity levels of n.c.a. I-131-MIBG. Even with no improvement in tumour uptake, n.c.a. MIBG may be the favoured formulation for therapeu tic applications to reduce the molar amount of drug injected. ((C) 2000 Lip pincott Williams & Wilkins).