Comparative Investigation of the Possibilities of PET Visualization of Gliomas with Different Tumor specific Radiopharmaсeuticаls
The aim of our work is generalizing the experience of the first comparative study of the diagnostic capabilities of positron emission tomography (PET) with a several tumor tropic radiopharmaceuticals (TRP) for detecting glioma tumors. Materials and methods. The study involved 87 pati ents with histologically verified gliomas: with glioblastoma multiforme – 33 patients, anaplastic astrocytoma (AA) – 23, benign astrocytoma (BA) – 16, with post operative cysts – 15 patients. PET was performed on scanners Discovery 690 (GE) and Ecat Exact HR (Siemens) with tumor tropic RP: 18F fluoro deoxyglucose (18F FDG), 11C sodium butirate (11C BN), 11C L methionine (11C MET) and 11C choline (11C CHOL). Results. Glioblastoma multiforme is well visualized in the study with all TRP. Anaplastic and benign astrocytomas effective visualized with 11C MET and 11C CHOL. Capture of 11C BN has been very low. Visualization of malignant tumors with 18F FDG was difficult because of increased accumula tion of radiotracer in the cortex of the brain and high vari ability of the glycolysis rate in tumors. Accumulation index values (AI) obtained by PET with 11C CHOL, were 2.5 times higher than that of 11C MET, and 4 times higher than for the C BN in AA was also increased, but in BA accumulation of choline in the intact cortex. Conclusion. PET with 11C CHOL was the most sensitive method for detection of brain gliomas. The advantage of PET with 11C MET is the ability to visualize the entire volume of viable tumor tissue. PET with 11C BN is effective in identi fying malignant gliomas and allows to evaluate a number of important properties: the degree vascularisation and the rate of capture and utilization of fatty acids in tumors.