111In-DTPA0-octreotide (Octreoscan), 131I-MIBG and other agents for radionuclide therapy of NETs

Abstract

This paper is a critical review of the literature on NET radionuclide therapy with (111)In-DTPA(0)-octreotide (Octreoscan) and (131)I-MIBG, focusing on efficacy and toxicity. Some potential future applications and new candidate therapeutic agents are also mentioned. Octreoscan has been a pioneering agent for somatostatin receptor radionuclide therapy. It has achieved symptomatic responses and disease stabilization, but it is now outperformed by the corresponding β-emitter agents (177)Lu-DOTATATE and (90)Y-DOTATOC. (131)I-MIBG is the radionuclide therapy of choice for inoperable or metastatic phaeochromocytomas/paragangliomas, which avidly concentrate this tracer via the noradrenaline transporter. Symptomatic, biochemical and tumour morphological response rates of 50-89%, 45-74% and 27-47%, respectively, have been reported. (131)I-MIBG is a second-line radiopharmaceutical for treatment of enterochromaffin carcinoids, mainly offering the benefit of amelioration of hormone-induced symptoms. High specific activity, non-carrier-added (131)I-MIBG and meta-astato((211)At)-benzylguanidine (MABG) are tracers with potential for enhanced therapeutic efficacy, yet their integration into clinical practice awaits further exploration. Amongst other promising agents, radiolabelled exendin analogues show potential for imaging and possibly therapy of insulinomas, while preclinical studies are currently evaluating DOTA peptides targeting the CCK-2/gastrin receptors that are overexpressed by medullary thyroid carcinoma cells.

Sequelae and survivorship in patients treated with 131I-MIBG therapy

“…With radionuclide therapy, haematological side effects have been reported in the region of 2–21% (Gedik et al , 2008; Nwosu et al , 2008; Kunikowska et al , 2011; Bomanji and Papathanasiou, 2012; Gulenchyn et al , 2012). Different chemotherapies have a different toxicity profile.…”

“…Response to 131 I-MIBG therapy, which is not in the remit of this paper, would be measured hormonally with serum chromogranin A and/or urinary 5-HIAA for NETs. 131 I-meta-iodobenzylguanidine would improve the condition in 40–80% of patients (Loh et al , 1997; Mukherjee et al , 2001; Gedik et al , 2008; Nwosu et al , 2008; Bomanji and Papathanasiou, 2012) and radiologically by demonstrating a reduction in size, though this occurs less often (at 20–30%) and by patients' report of symptoms at 50–89% (Gedik et al , 2008; Nwosu et al , 2008; Shilkrut et al , 2010). …”

Zalecenia ogólne dotyczące postępowania w nowotworach neuroendokrynnych układu pokarmowego (rekomendowane przez Polską Sieć Guzów Neuroendokrynnych)

“…This treatment is primarily palliative, and enables reduction of pain and carcinoid syndrome symptoms. A treatment with radical intention is rarely possible [143,144]. Contraindications for the therapy include bone marrow suppression (according to the above criteria).…”

Neuroendocrine Tumors of the Lung: A Comprehensive Overview

“…If positive, treatment with the radiolabeled somatostatin analog 177 Lu-DOTATATE or 90 Y-DOTATOC can be considered [11,12]. In the case of uptake of 123 I-MIBG in the tumor, treatment with 131 MIBG may be of value [13]. These kind of treatments are only indicated in advanced disease.…”