Technetium-99m sestamibi brain single-photon emission tomography for detection of recurrent gliomas after radiation therapy

Abstract

Technetium-99m sestamibi (MIBI), an alternative radiopharmaceutical for myocardial perfusion imaging, has also been proposed for use as an imaging agent for various tumours, including breast cancer, lung cancer, lymphomas, melanomas and brain tumours. After routine radiation therapy, deteriorating clinical status or treatment failure may be due to either radiation-induced changes or recurrent tumour. Computed tomography and magnetic resonance imaging offer imperfect discrimination of tumour viability and radionecrosis. Against this background we undertook a retrospective study of 35 malignant glioma patients in whom clinical deterioration had occurred, in order to clarify the value of 99mTc-MIBI SPET in identifying tumour recurrence. SPET was performed 15 min after intravenous injection of 1110 MBq with a dual-headed gamma camera using a fan-beam collimator. Transverse, coronal and sagittal views were reconstructed. Intense MIBI uptake was found in 31 patients. This uptake was correlated with tumour recurrence as proved by histology and/or rapid, fatal evolution of these cases. The statistical analysis performed on this population of patients with MIBI uptake revealed a group of patients with a long mean survival and a group with a short mean survival. Two subgroups were found within each of these groups, according to the functional index ratio (tumour uptake/pituitary gland uptake ratio). No MIBI uptake was found in four patients who are still alive and can be considered to be disease-free. In those cases showing MIBI uptake, death occurred an average of 6.69 months following brain SPET. According to our results, the specificity and sensitivity of 99mTc-MIBI brain SPET seem to be high. Moreover, this technique is more accurate than computed tomography or magnetic resonance imaging for discriminating between tumour recurrence and radionecrosis.

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

“…33) Meningiomas usually show high 99m Tc-MIBI uptake because of the absence of the blood-brain barrier and the hypervascularity, whereas 99m Tc-MIBI uptake is minimum in normal brain tissue due to the blood-brain barrier. In this study, use of the contralateral normal brain tissue as a control for 99m Tc-MIBI SPECT resulted in extraordinarily high values for the T/N ratio in meningiomas.…”

“…6,22) Resistance to anticancer drugs such as vincristine, etoposide, doxorubicin, and methotrexate is thought to be associated with Pgp expression, so characterization of its expression in meningioma may be important for the prognosis of chemotherapy efficacy. 10,33) Little is known about the relationship between Pgp or MDR-1 mRNA expression and the response rate to chemotherapy in meningiomas. Recently, hydroxyurea, a ribonucleotide reductase inhibitor, was used in adjuvant chemotherapy for patients with recurrent or unresectable meningioma, and was effective in halting the growth of enlarging benign meningiomas but not malignant meningiomas.…”

Multimodality image fusion in dose escalation studies of brain tumors

“…The conventional MRI sequences might enhance the necrotic regions as well as the active tumor, whereas the SPECT/PET images can differentiate the two 9 , 16 . The single voxel proton magnetic resonance spectroscopy (MRS) and imaging, MRSI) has the potential to distinguish tumor relapse/necrosis and correlation of tumor grade 17 , 18 , 19 , 20 .…”

“…Owing to the potential difference between the intercellular and intracellular compartments, the molecule can penetrate the cytoplasmic membrane and bind to mitochondria. For this reason, the tracer was proposed to detect brain tumor relapse and thereby distinguish between radiation or chemotherapy necrosis and viable lesions with high sensitivity and specificity 9 . In the cerebral region, the sestaMIBI molecule distributes mainly in the scalp and in the choroid plexus.…”

“…This information is vital for dose escalation to the viable tumor regions and also for monitoring the effectiveness of therapy. Thus, combining the information from CT, MRI, and SPECT/PET imaging studies could help radiation oncologists to define the target with a greater degree of certainty 9 . This study has been undertaken to explore the utility of integrating the images from CT, MRI, and SPECT for 3D planning with escalated doses (biological conformation) of brain tumors.…”