THE ROLE OF 131-IODINE-METAIODOBENZYLGUANIDINE SCANNING IN THE CORRELATIVE IMAGING OF PATIENTS WITH NEUROBLASTOMA

Objective. Metaiodobenzylguanidine (MIBG) scans were studied to determ ine the impact of the scan results on the clinical treatment of pediat ric patients with neural crest tumors. Methods. Serial scans were revi ewed retrospectively for 27 patients with neural crest tumors: 25 with initial diagnoses of neuroblastoma (NB), 1 with ganglioneuroblastoma, and 1 with ganglioneuroma (GN). Results were compared with bone scans and computed tomography scans, as well as surgical pathologic finding s. Results. At initial diagnosis, when compared with bone and computed tomographic scans, MIBG imaging did not identify any unsuspected lesi ons that resulted in a change in staging. Thirteen patients with NE wh o had initially positive MIBG scan results had serial studies that nor malized during therapy. However, after completion of therapy, 8 of 13 had relapses of the disease. Although areas of active disease were wel l delineated by other standard imaging modalities for all 8, only 4 (5 0%) had MIBG study results that were positive in sites of relapse. The re were 4 cases of GN (1 at diagnosis and 3 after therapy for NE) demo nstrating an uptake of MIBG that was similar in appearance to that in NE. Conclusions. MIBG imaging did not change the staging or alter trea tment during therapy for any patient. Normalization of positive study results was an unreliable indicator of outcome for children with NE. F urthermore, when relapse occurred, MIBG scans identified only 50% of t hose with active NE. The uptake of MIBG in GN was indistinguishable fr om that in NE. In this series, the results of serial MIBG studies did not have a significant impact on patient treatment.