[123I]IBZM uptake in metastatic melanoma

In this report we describe our experience with [123I]IBZM ([123I]-(S)-2-hydroxy-3-iodo-6-methoxy-N-[(1-ethyl-2-pyrrolid inyl)methyl] benzamide), used to image the lesions in a female patient affected by metastatic melanoma. Marked uptake of [123I]IBZM in an area corresponding to a palpable lymph-nodal mass was observed in images collected 2 and 5 hours after i.v. tracer administration. Tumour to non-tumour ratios evaluated on planar maps were found to be 2.04 and 2.35, respectively. Surgical excision and histological examination of inguinal nodes confirmed the presence of melanoma lymph-nodal metastases. Although scintigraphy with radiolabelled [123I]IBZM is widely used for neuro-psychiatric disorders, we have found no reports in the literature of any application of this tracer in oncology. Even if the biological bases underlying the findings reported here remain unclear (although they are probably related to the neural crest origin of the melanocytes), the quality of imaging found suggests that this tracer may provide a new diagnostic tool for the imaging of melanoma tumours.