OBJECTIVE: To investigate the value of somatostatin receptor scintigraphy (SSRS) in the diagnosis of optic nerve sheath meningiomas (ONSMs). DESIGN: Prospective, comparative case series. PARTICIPANTS: SSRS was used to investigate 68 orbits in 61 patients diagnosed with an orbital tumor. METHODS: Patients were injected intravenously with 200 MBq of indium-111 ((111)In)-octreotide. SSRS with single photon emission computed tomography (SPECT) was performed 24 hours after injection. MAIN OUTCOME MEASURES: The (111)In-octreotide uptake in orbital lesions was determined by semiquantitative uptake-ratio analysis (lesion/brain) on attenuation-corrected transverse SPECT slices. RESULTS: All orbital meningiomas, including 14 ONSMs and 12 spheno-orbital meningiomas, showed high median (111)In-octreotide uptake ratios of 7.2 (range, 4.6-15.4) and 16.3 (range, 4.6-15.4), respectively. In 7 patients with a diagnosis of ONSM, the SSRS uptake ratio was significantly decreased 2.7 (1-6.8) after treatment with 54 Gy of radiotherapy. Median uptake ratios of other tumors were vascular anomalies/vascular tumors, 1.2 (range, 0.5-3.3); non-Hodgkin lymphomas, 2.9 (range, 0.9-4.2); optic nerve gliomas, 1.5 (range, 0.2-3.3); and idiopathic orbital inflammation, 1.6 (range, 1.4-1.9). By using a threshold uptake ratio of 5.9, the sensitivity of SSRS with (111)In-octreotide for ONSM was 100%, with a specificity of 97.2%. CONCLUSIONS: SSRS is a useful additional tool in diagnosing ONSM and has 100% sensitivity and 97% specificity at a threshold uptake ratio of 5.9.
OBJECTIVE: To investigate the value of somatostatin receptor scintigraphy (SSRS) in the diagnosis of optic nerve sheath meningiomas (ONSMs). DESIGN: Prospective, comparative case series. PARTICIPANTS: SSRS was used to investigate 68 orbits in 61 patients diagnosed with an orbital tumor. METHODS:Patients were injected intravenously with 200 MBq of indium-111 ((111)In)-octreotide. SSRS with single photon emission computed tomography (SPECT) was performed 24 hours after injection. MAIN OUTCOME MEASURES: The (111)In-octreotide uptake in orbital lesions was determined by semiquantitative uptake-ratio analysis (lesion/brain) on attenuation-corrected transverse SPECT slices. RESULTS: All orbital meningiomas, including 14 ONSMs and 12 spheno-orbital meningiomas, showed high median (111)In-octreotide uptake ratios of 7.2 (range, 4.6-15.4) and 16.3 (range, 4.6-15.4), respectively. In 7 patients with a diagnosis of ONSM, the SSRS uptake ratio was significantly decreased 2.7 (1-6.8) after treatment with 54 Gy of radiotherapy. Median uptake ratios of other tumors were vascular anomalies/vascular tumors, 1.2 (range, 0.5-3.3); non-Hodgkin lymphomas, 2.9 (range, 0.9-4.2); optic nerve gliomas, 1.5 (range, 0.2-3.3); and idiopathic orbital inflammation, 1.6 (range, 1.4-1.9). By using a threshold uptake ratio of 5.9, the sensitivity of SSRS with (111)In-octreotide for ONSM was 100%, with a specificity of 97.2%. CONCLUSIONS: SSRS is a useful additional tool in diagnosing ONSM and has 100% sensitivity and 97% specificity at a threshold uptake ratio of 5.9.
Authors: Guillermo Maza; Somasundaram Subramaniam; Juan C Yanez-Siller; Bradley A Otto; Daniel M Prevedello; Ricardo L Carrau Journal: J Neurol Surg B Skull Base Date: 2019-01-10