TY - JOUR T1 - <sup>11</sup>C-Methionine &amp; <sup>18</sup>F-FDG PET-CT Scans in Clinical Management of Cerebral Tumors. <em/> JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1686 LP - 1686 VL - 59 IS - supplement 1 AU - RAJNISH SHARMA AU - Maria Dsouza AU - Sanjiv Saw AU - Yachna Solanki AU - Santosh Pandey AU - Tarakant Kumar AU - Ajay Singh Y1 - 2018/05/01 UR - http://jnm.snmjournals.org/content/59/supplement_1/1686.abstract N2 - 1686Objectives: PET-CT using 11C-Methonine ([11C]-MET) has been reported to detect brain tumors with high Sensitivity &amp; Specificity. In this study we have evaluated the potential of [11C]-MET in recurrent Cerebral tumors. Comparison of F18-FDG with [11C]-MET has also been done. Methods: 96 subjects of brain tumor treated by surgery, chemotherapy or radiotherapy were subjected to [18F]-FDG, [11C]-MET &amp; MRI scan. The lesion were analysed semi-quantitatively using tumor to normal contralateral ratio. Diagnosis was confirmed by surgery, stereotactic biopsy, clinical follow up, MRI or CT scans. Results: Tumor recurrence was found in 8 out of 33 patients on [F-18] FDG scan while [11C]-MET was able to detect recurrence in 27 out of 33 patients in low grade gliomas. 3 of these patients were false positive for presence of recurrence of tumor &amp; later found to be harbouring necrosis. Among Oligodendroglioma, Medulloblastoma &amp; High Grade Glioma out of 63 patients 58 were found to be concordant [11C]-MET &amp; [18F]-FDG scans. On semi-quantitative analysis mean T/ NT ratio was found to be 2.86 ± 0.91 for lesions positive for recurrence of tumors &amp; 1.14 ± 0.82 for lesions negative for recurrence of tumor on [11C]-MET scan. While the ratio for [18F]-FDG scan on semi-quantitative analysis was found to be 2.05 ± 1.04 for lesions positive for recurrence of tumors &amp; 0.52 ± 0.15 for lesions negative for recurrence of tumors. Conclusions: The study highlight that [11C]-MET is superior to [18F]-FDG PET scans to detect recurrence in low grade glioma. A cut off value of target to non target value of 1.52 is a useful parameter to distinguish benign from malignant lesion on a [11C]-MET Scan. Both [18F]-FDG &amp; [11C]-MET scan were found to be useful in High Grade Astrocytoma, Oligodendroglioma &amp; Medulloblastoma. ER -