RESUMEN
Thallium-201 SPECT studies were done on 32 patients with brain tumors : 20 patients with glioma, 3 patients with meningiomas, 2 patients with metarastasis, 2 patients with pineal tumors, 1 patient each with germinoma, neurinoma, neurocytoma, and 2 postradiation patients. A 201T1 index was based on the ratio of thallium uptake tumor versus the homologous contralateral brain. It was calculated and compared with tumor histology. There was a substantial uptake of 201T1 in high grade gliomas with no uptake in low grade glioma. Meningiomas and metastatic tumors show hot uptake, revealing that 201T1 uptake is not exclusive to high grade gliomas. In conclusion, 201TI SPECT could distinguish the benign and malignancy, and seems to be useful in the follow-up after treatment, to period low-or high-grade lesions.