Noninvasive differentiation of meningiomas from other brain tumours using combined 111Indium-octreotide/99mtechnetium-DTPA brain scintigraphy.
We have studied prospectively 47 patients with CNS tumours including 16 meningiomas and 33 other tumours using combined 111In-octreotide and 99mTc-DTPA brain scintigraphy. 111In-octreotide scintigraphy was used to image somatostatin receptors (SSR) and 99mTc-DTPA scintigraphy was used to assess the integrity of the blood-brain barrier (BBB). A total of 32 tumours (65%) were detected. All SSR positive tumours also had positive 99mTc-DTPA scans and all SSR negative tumours were negative on 99mTc-DTPA scans. Among the tumours located outside the BBB, all meningiomas and two out of six schwannomas were positive on combined SSR/99mTc-DTPA scintigraphy. Among the tumours located inside the BBB, seven out of nine gliomas grade I-III were negative, whereas all glioblastomas were positive. Other positive tumours included one malignant non-Hodgkin lymphoma and two cerebral metastases. SSR scintigraphy alone was non-specific in the diagnosis of meningiomas, as 16 non-meningiomatous tumours also had positive SSR scans probably due to a breakdown of the BBB (excluding the malignant lymphoma). Measuring the tumour-to-background ratio on SSR scans improved specificity, but sensitivity was decreased below 70% because some meningiomas were only slightly positive. Only the ratio of SSR scintigraphy to conventional 99mTc-DTPA brain scintigraphy (SSR-to-BS index) allowed a reliable differentiation of meningiomas from other CNS tumours, most notable from schwannomas (sensitivity: 94%; specificity: 100%). Our results support the usefulness of combined SSR and conventional brain scintigraphy in the noninvasive pre-operative diagnosis of meningiomas.
Barth
A
A
Department of Neurosurgery, University of Berne, Inselspital, Switzerland.
Haldemann
A R
AR
Reubi
J C
JC
Godoy
N
N
Rösler
H
H
Kinser
J A
JA
Seiler
R W
RW
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001812:Blood-Brain Barrier / Q000502:physiology; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D008579:Meningioma / Q000000981:diagnostic imaging* / Q000601:surgery; D008875:Middle Aged; D015282:Octreotide / Q000031:analogs & derivatives*; D011877:Radionuclide Imaging; D017481:Receptors, Somatostatin / Q000032:analysis; D012680:Sensitivity and Specificity; D016284:Technetium Tc 99m Pentetate
D017481:Receptors, Somatostatin; C094279:indium-111-octreotide; D015282:Octreotide; D016284:Technetium Tc 99m Pentetate