Technetium-99m Sestamibi Single Photon Emission Computed Tomography Findings Correlated With P-glycoprotein Expression, Encoded by the Multidrug Resistance Gene-1 Messenger Ribonucleic Acid, in Intracranial Meningiomas

Abstract

The present study evaluated whether technetium-99m sestamibi ( 99m Tc-MIBI) single photon emission computed tomography (SPECT) characteristics of intracranial meningioma are correlated with the histological malignancy, proliferative potential, and P-glycoprotein (Pgp) expression, encoded by the multidrug resistance gene-1 (MDR-1) messenger ribonucleic acid (mRNA). Twenty-one patients with intracranial meningiomas, including 17 benign and four nonbenign meningiomas, underwent 99m Tc-MIBI SPECT imaging at 15 minutes (early) and 3 hours (delayed) after injection. The tumor-to-normal pituitary gland ratio was calculated on both early (ER) and delayed (DR) images. Retention index (RI) was calculated using the following formula: (DR -ER)/ER × 100%. Meningioma specimens were examined by immunohistochemistry using anti-Pgp and MIB-1 monoclonal antibody. MDR-1 mRNA expression was also investigated using reverse transcription-polymerase chain reaction assay. 99m Tc-MIBI was highly accumulated and retained in the tumors. 99m Tc-MIBI SPECT findings were not related to MIB-1 labeling index. 99m Tc-MIBI SPECT RI of the Pgp-positive group (-9.12 ± 22.27%) was significantly lower than that of the Pgp-negative group (28.79 ± 22.80%) (p ＝ 0.0016). No significant difference was seen in ER and DR between the positive and negative groups. These results show that 99m Tc-MIBI may not be useful for determining proliferative potential and histological malignancy, but could predict anticancer drug resistance related to the expression of MDR-1 mRNA and its gene product Pgp in patients with intracranial meningiomas.

Pituitary Incidentalomas Detected with Technetium-99m MIBI in Patients with Suspected Parathyroid Adenoma: Preliminary Results

“…This strongly associates with pituitary adenomas. [781021] Our study supports this data and suggests a simple semiquantitative index to diagnose underlying pituitary abnormalities.…”

Oncologic Applications of Sestamibi: In Vivo Imaging of Multi-Drug Resistance

“…Tc-Sestamibi is significantly lower in P-gp positive meningiomas as compared to P-gp positive intracranial meningiomas and hence it can be used as a marker of P-gp-related MDR [76]. Also based on a small number of patients, it has been concluded that 99m Tc-Sestamibi has the potential to predict P-gp-related MDR in pituitary adenomas [77].…”

Single-Photon Emission Computed Tomography [Neuro-SPECT] Imaging of Brain Tumors

“…99m Tc − MIBI has not been extensively evaluated in meningiomas and few reports exist. A small-scale study found no correlation between Ki-67 index and tracer uptake; still 99m Tc-MIBI could predict anticancer drug resistance related to the expression of MDR-1 mRNA and its gene product P-gp (Kunishio et al 2003 ). Tumor 99m Tc-TF uptake is not infl uenced by MDR phenotype expression and has been proven suitable for discriminating malignant from benign meningiomas, with an L/N tracer uptake value of 9.6 being the optimal threshold (Fotopoulos et al 2008 ).…”