Usefulness of 123I-MIBG scintigraphy in the evaluation of patients with known or suspected primary or metastatic pheochromocytoma or paraganglioma: results from a prospective multicenter trial.

UNLABELLED: Although (123)I-MIBG has been in clinical use for the imaging of pheochromocytoma for many years, a large multicenter evaluation of this agent has never been performed. The present study was designed to provide a prospective confirmation of the performance of (123)I-MIBG scintigraphy for the evaluation of patients with known or suspected primary or metastatic pheochromocytoma or paraganglioma. METHODS: A total of 81 patients with a prior history of primary or metastatic pheochromocytoma or paraganglioma and 69 with suspected pheochromocytoma or paraganglioma based on symptoms of catecholamine excess, CT or MRI findings, or elevated catecholamine or metanephrine levels underwent whole-body planar and selected SPECT 24 h after the administration of (123)I-MIBG. Images were independently interpreted by 3 masked readers, with consensus requiring agreement of at least 2 readers. Final diagnoses were based on histopathology, correlative imaging, catecholamine or metanephrine measurements, and clinical follow-up. RESULTS: Among 140 patients with definitive diagnoses (91, disease present; 49, disease absent), (123)I-MIBG planar scintigraphy had a sensitivity and specificity of 82%. For patients evaluated for suspected disease, sensitivity and specificity were 88% and 84%, respectively. For the subpopulations of adrenal (pheochromocytoma) and extraadrenal (paraganglioma) tumors, sensitivities were 88% and 67%, respectively. The addition of SPECT increased reader confidence but minimally affected sensitivity and specificity. CONCLUSION: This prospective study demonstrated a sensitivity of 82%-88% and specificity of 82%-84% for (123)I-MIBG imaging used in the diagnostic assessment of primary or metastatic pheochromocytoma or paraganglioma.

(123)I-mIBG scintigraphy in patients with known or suspected neuroblastoma: Results from a prospective multicenter trial.

BACKGROUND: A prospective trial was conducted to confirm the diagnostic performance of (123)I-mIBG scintigraphy in patients with known or suspected neuroblastoma. PROCEDURE: 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. RESULTS: 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). CONCLUSIONS: 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.

Volume and impact of second-opinion consultations by radiologists at a tertiary care cancer center: data.

RATIONALE AND OBJECTIVES: Patients with cancer who are referred to a dedicated oncology center usually have undergone previous imaging studies that the oncologists typically desire to have reviewed by radiologists. Such reinterpretations can be complex and time-consuming, yet many institutions do not systematically account for them as part of the total workload. The purpose of this study was to ascertain the numbers and types of second-opinion consultations performed by radiologists at a tertiary care cancer center, and to assess their effect on work volume. MATERIALS AND METHODS: A survey of referring clinicians was undertaken to evaluate the numbers and types of second-opinion consultations requested of radiologists at the Dana Farber Cancer Institute during a 12-month period. Consultations included review of studies from outside institutions, and cases from Dana Farber in which further comparison was needed. The number of consultations requiring additional tumor size measurements was tallied. The mean daily number of new studies interpreted by radiologists was used as a benchmark of work volume. RESULTS: Radiologists performed 4,664 consultations during 254 workdays, interpreting a mean of 18 additional studies (range, 4-42) per day as a result of referrals for second opinion. These included 3,638 (78%) cross-sectional studies (ie, computed tomographic [CT], magnetic resonance [MR], and ultrasound [US] studies), 674 (14%) mammograms, 220 (5%) plain radiographs, 132 (3%) nuclear medicine scans, and one galactogram. Of the 4,664 consultations, 1,306 (28%) were performed to obtain tumor measurements, many of these involving five to 10 bidimensional calculations per study. A mean of 101 new examinations per day was performed by radiologists during the same 12-month period, including cross-sectional studies (CT and US scans) (56%), plain radiographs (34%), and mammograms (11%). MR imaging was not performed. CONCLUSION: Second-opinion consultations increased the average daily work volume by 18%. This has implications for workforce, as well as for compensation in terms of relative value units and finances for this previously unquantified service.