CLINICAL-PATIENT STUDIES 99m Tc-Tetrofosmin brain SPECT in the assessment of meningiomas—correlation with histological grade and proliferation index Andreas D.Fotopoulos Æ George A.Alexiou Æ Ann Goussia Æ Athanasios Papadopoulos Æ Athanasios P. Kyritsis Æ Konstantinos S. Polyzoidis Æ Spyridon Voulgaris Æ Spyridon Tsiouris Received: 16 September 2007 / Accepted: 22 April 2008 / Published online: 6 May 2008 Ó Springer Science+Business Media, LLC. 2008 Abstract Meningiomas accountfor about30% of all intracranial tumors. Evaluation of their proliferation rate is useful for assessing their biological behavior. We evaluated prospectively whether 99m Tc-Tetrofosmin ( 99m Tc-TF) uptake in meningiomas correlates with cellular proliferative activity and with tumor grade. We prospectively studied 18 menin- gioma cases.Brain single-photon emissioncomputed tomography (SPECT) by 99m Tc-TF was performed within a week prior to surgical excision. In the excised tumor speci- mens we assessed Ki-67 antigen expression. 14 of 18 patients had benign meningiomas, while the remaining four had anaplastic meningiomas. A significant correlation was found between both 99m Tc-TF uptake and tumor grade (r = 0.722, P = 0.001)and between 99m Tc-TF uptakeand Ki-67 expression (r = 0.930, P \ 0.001).There was a significant correlation between the intensity of tracer uptake and tumor recurrence at 1 yearpostoperative (r = 0.574, P = 0.02). This pilotstudy implies that 99m Tc-TF brain SPECT could prove useful in differentiating benign from anaplastic men ingiomas and is a potential indicator of theirproliferative activity. Keywords Meningioma 99m Tc-Tetrofosmin Cell proliferation Ki-67 MIB-1 Introduction Meningiomas account fornearly 30% ofall intracranial tumors, whereas 2–3% of the population in autopsy studie had an incidental asymptomatic meningioma [ 1]. They are usually diagnosed after the third decade of life and they a twice as frequent in women than in men. According to the World Health Organization (WHO), meningiomas are clas- sified into three grades, benign (grade I), atypical (grade I and anaplastic (grade III) [2]. Although they usually have a relatively benign clinical course and only a 15% recurrenc rate,atypical and malignant ones are associated with high recurrence rates and poor outcome [3, 4]. Tumorprognosisdependson itsbiologicalbehavior, which is determined by various cellular characteristics. As in all brain tumors, the proliferation potential of menin- giomas is essential for their biological characterization and has significant prognostic implications, thus being impor- tantfor patientmanagement. The nuclear antigen Ki-67 expressed by proliferating cells has become available for routinely processed paraffin section and is considered the most reliable of all other methods, since Ki-67 is expressed in nearly all phases of the cell cycle, with the exception of G 0 phase [5–7]. The MIB-1 antibody reacts to the Ki-67 nuclearantigen in formalin-fixed tissue and was proved sensitive and reliable in determining meningioma grade A. D. Fotopoulos A.Papadopoulos S. Tsiouris Department of Nuclear Medicine, University of Ioannina School of Medicine, P.O.Box 103, Neohoropoulo, Ioannina 455 00, Greece G. A. Alexiou (&) K. S. Polyzoidis S.Voulgaris Department of Neurosurgery, University of Ioannina School of Medicine, P.O.Box 103, Neohoropoulo, Ioannina 455 00, Greece e-mail: alexiougrg@yahoo.gr; me01929@cc.uoi.gr A. Goussia Department of Pathology, University of Ioannina School of Medicine, P.O.Box 103, Neohoropoulo, Ioannina 455 00, Greece A. P. Kyritsis Department of Neurology, University of Ioannina School of Medicine, P.O.Box 103, Neohoropoulo, Ioannina 455 00, Greece 123 J Neurooncol (2008) 89:225–230 DOI 10.1007/s11060-008-9611-8