11C-MET PET/CT and Advanced MRI in the Evaluation of Tumor Recurrence in High-Grade Gliomas

• Published in: Clinical nuclear medicine 2014-09, Vol.39 (9), p.791-798
• Main Authors: D’Souza, Maria M., Sharma, Rajnish, Jaimini, Abhinav, Panwar, Puja, Saw, Sanjiv, Kaur, Prabhjot, Mondal, Anupam, Mishra, Anil, Tripathi, Rajendra P.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Brain Neoplasms - diagnostic imaging; Brain Neoplasms - pathology; Brain Neoplasms - therapy; Carbon Radioisotopes; Female; Glioma - diagnostic imaging; Glioma - pathology; Glioma - therapy; Humans; Magnetic Resonance Imaging; Male; Methionine - analogs & derivatives; Middle Aged; Multimodal Imaging; Neoplasm Recurrence, Local - diagnostic imaging; Neoplasm Recurrence, Local - pathology; Positron-Emission Tomography; Radiopharmaceuticals; Tomography, X-Ray Computed
• ISSN: 0363-9762; 1536-0229
• DOI: 10.1097/RLU.0000000000000532

OBJECTIVESThe purpose of this study was to evaluate the performance of l-[methyl-()C]methionine (C-MET) PET/CT and MRI (with the inclusion of advanced imaging techniques, namely, MR spectroscopy and MR perfusion) in the assessment of tumor recurrence in high-grade gliomas. PATIENTS AND METHODSTwenty-nine patients with high-grade gliomas who underwent surgical resection, external beam radiation therapy, and standard regimens of chemotherapy were subjected to MRI (conventional, MR perfusion, and MR spectroscopy) and C-MET PET/CT scans. A definitive diagnosis was made based on histopathology and/or long-term clinical and radiological follow-up. Several indices were obtained for lesion characterization, namely, SUVmean, SUVmax, and mean lesion-to-normal tissue on PET/CT, as well as relative cerebral blood volume and choline-to-creatine ratio on MRI. RESULTSHistological examination revealed viable tumor cells in 19 cases, whereas the remaining 10 were deemed to be negative based on histology (3 cases) or long-term follow-up (7 cases). All the quantitative indices mentioned previously tended to be higher in patients with tumor recurrence/residual. The sensitivity, specificity, and accuracy of C-MET PET/CT in identifying tumor recurrence/residual were 94.7%, 80%, and 89.6%, respectively, whereas that of MRI were 84.2%, 90%, and 86.2%, respectively. CONCLUSIONSBoth C-MET PET/CT and MRI (with the inclusion of advanced MRI techniques) demonstrated a high diagnostic performance in the identification of tumor residual/recurrence in high-grade gliomas posttherapy. Although C-MET PET/CT seemed to be more sensitive, whereas advanced MRI seemed more specific, there was no statistically significant difference in the diagnostic performance of either modality in the present study. Further studies with a larger group of patients are warranted.