Correlation between 99mTc-HYNIC-octreotide SPECT/CT somatostatin receptor scintigraphy and pathological grading of meningioma.

The aim of this study was to explore the association of (99m)Tc-HYNIC-octreotide SPECT/CT somatostatin receptor scintigraphy (SRS) with the pathological grading and expression of somatostatin receptor 2 (SSTR2) for meningioma, and to define possible roles of SRS in the pathological grading of meningioma. Thirty patients with meningiomas diagnosed by MRI and treated with (99m)Tc-HYNIC-octreotide SPECT/CT SRS. Meningioma tissues were obtained from analyzing pathological grading and measuring the expression of SSTR2 with immunohistochemical staining. The meningioma side (T) to the contralateral side (NT) ratios (T/TN) of radioactive counts were calculated to investigate their association with the pathological grading of meningioma and the expression of SSTR2. All 30 cases showed high meningioma radioactivity accumulation using SRS with a sensitivity of 100 %, while CT scans only detected 25 cases with a sensitivity of 83 %. Twenty cases with grade I meningioma had a T/NT ratio of 3.80 ± 1.67, which was significantly lower than the other 10 cases (9.57 ± 3.78) with a grade II meningioma (P < 0.01). All meningiomas expressed SSTR2 as detected by immunohistochemical staining, and the T/NT ratio was positively associated with the pathological grading of meningioma and the expression of SSTR2 (with r of 0.784 and 0.805, respectively). (99m)Tc-HYNIC-octreotide SPECT/CT SRS is a sensitive technique for detecting meningioma, and the T/NT ratio of the SRS data closely correlates with the pathological grade of meningioma and the expression of SSTR2.