123I‐mIBG scintigraphy in patients with known or suspected neuroblastoma: Results from a prospective multicenter trial

Abstract

A prospective trial was conducted to confirm the diagnostic performance of (123)I-mIBG scintigraphy in patients with known or suspected neuroblastoma. One hundred patients (mean age 4.7 years) were enrolled, 86 with a previous diagnosis of neuroblastoma, 13 with suspected disease based upon symptoms, imaging findings, and elevated catecholamines, and one adult with an abdominal tumor thought to be of neuroendocrine origin. All patients underwent whole-body planar imaging 24 hr following IV administration of 1-10 mCi (37-370 MBq) (123)I-mIBG. SPECT imaging of the thorax/abdomen/pelvis was performed in 51 patients. Images were interpreted by three blinded readers, with consensus requiring agreement of at least two readers. Disease status was confirmed by histopathology, imaging results, catecholamine measurements, and follow-up. Sixty-four patients had active disease, 30 were without disease, and 6 were judged indeterminate because of insufficient confirmatory data. (123)I-mIBG scintigraphy had a sensitivity of 88% (56/64) and specificity of 83% (25/30). Sensitivity was 91% (30/33) among the subset of subjects who had both planar and SPECT imaging. Among 53 patients with recent histopathology, sensitivity and specificity were 93% and 92%, respectively. Most false-negative interpretations were in patients with minimal residual disease (n = 4), while false-positive interpretations generally involved atypical adrenal or other physiological uptake (n = 4). This prospective multicenter trial of (123)I-mIBG scintigraphy documents high sensitivity and specificity of this imaging technique in patients with both newly diagnosed and previously treated neuroblastoma.