Objective: To assess the value and feasibility of positron-emission tomography-magnetic resonance imaging (PET-MRI) fusion technology in delineating tumor boundaries and positioning biopsy targets of gliomas so as to facilitate the diagnosis and treatment of gliomas.
Methods: A total of 18 patients with a preoperative diagnosis of gliomas discharged from our hospital from January 2010 to April 2011 were recruited. All of them underwent the preoperative examinations of MRI, fluorodeoxyglucose (FDG) PET and fluoroethyl-choline (FECH) PET. The digital image data were transferred into Brain LAB planning software and three types of images automatically fused. The tumor contours were drawn on the basis of each image modality separately. The extent of tumor resection or biopsy target was determined on the integrated information including tumor contours on PET and MRI images and intraoperative observation of tumor texture.
Results: On PET scans, the average standard uptake value (SUV) of glioblastomas was higher than that of grade II-III gliomas. With regard to the patients with both biopsy and tumor resection, the pathological diagnosis of the specimen obtained from the PET-guided biopsy was consistent with that of subsequently resected tissue. All 11 patients undergoing tumor resection were classified according to relationship between the image-based tumor contour and actual extent of resection. Six of them benefited from contour delineated by FDG PET images and 3 of them benefited from FECH PET. The combined contribution ratio of both PET methods was 9/11.
Conclusion: PET-MRI fusion technology may accurately delineate tumor boundary and sensitively target the region of high proliferation or metabolism. A more radical resection and more accurate histological diagnosis can be thus achieved and yield a probably better prognosis of gliomas.