Gliomatosis cerebri evaluated by 18F?-methyl tyrosine positron-emission tomography

Abstract

Gliomatosis cerebri is a rare condition in which an infiltrative glial neoplasm spreads through the brain with preservation of the underlying structure. CT and MRI show diffuse abnormal density or signal, without mass effect, and because these findings are nonspecific, it is difficult to make a definitive diagnosis. Our purpose was to assess the usefulness of a new tumour-detecting amino acid tracer for positron-emission tomography (PET), L-[3-(18)F] alpha-methyl tyrosine (FMT), in patients with gliomatosis cerebri. We performed FMT PET, fluorodeoxyglucose FDG PET and MRI eight patients with gliomatosis cerebri and six with non-neoplastic disease, whose MRI also showed diffuse high signal on T2-weighted images. Standardised uptake (SUV) of FMT and FDG in the area of gliomatosis was obtained and the tumour-to-normal cortex (T/N) ratio of this was compared. The tumours were shown on FMT PET as areas of increased uptake, except in one patient with severe intracranial hypertension. There were significant differences between the SUV of FMT and the T/N ratio of FMT in patients and in controls (both P<0.01), and between the T/N ratio of FMT and FDG in patients ( P<0.01). Increased uptake of FMT PET strongly suggests neoplasia. FMT PET is valuable for differentiating gliomatosis cerebri from non-neoplastic diseases showing similar diffuse high signal on T2-weighted images and little contrast enhancement.

18F-FAMT uptake correlates with tumor proliferative activity in oral squamous cell carcinoma: comparative study with 18F-FDG PET and immunohistochemistry

“…FAMT is transported into cancer cell by L-type amino acid transporter 1 (LAT1) and showed high specificity for malignant tumors [9]. The clinical usefulness of FAMT-PET has been shown for the diagnosis of various types of malignant tumors such as brain tumor and lung cancer [9][10][11]. Previous studies showed the correlation of FAMT uptake with tumor proliferative activity evaluated by the Ki-67 immunostaining (Ki-67 labeling index, Ki-67 LI) as well as the prognosis of patients with non-small cell lung cancer (NSCLC) [9,10,12].…”

Gliomatosis Cerebri

“…Shintani et al [36] demonstrated that serial PET may be used to evaluate the extent of GC. Sato et al [39] examined 8 patients who had GC and 6 patients who had nonneoplastic disease with L-18 F-α-methyl tyrosine (FMT) PET and FDG PET. They observed significant differences between the standardized uptake (SUV) of FMT and the tumor-to-normal cortex (T/N) ratio of FMT in GC and in the controls, and between the T/N ratio of FMT and FDG in GC.…”

“…A few studies that describe PET fi ndings in GC using different tracers have been reported [36][37][38][39] . Dexter et al [38] using 2-18 F-2-deoxy-D-glucose (FDG) PET, demonstrated tumor-associated cortical suppression of glucose metabolism in areas of involvement in a single patient with GC.…”

“…Imaging features of MRS (a "neoplastic" spectral pattern of elevated Cho/NAA) and PET may be helpful to distinguish GC from non-neoplastic diseases [25][26][27][36][37][38][39] . Additionallaboratory findings are helpful in excluding infectious or infl ammatory diseases.…”

Diagnosis of maxillofacial tumor withl-3-[18F]-fluoro-α-methyltyrosine (FMT) PET: a comparative study with FDG-PET

“…L2 L-3-[18F]-Fluoro-ot-methyltyrosine (FMT)-PET was developed in our institute and showed high specificity for several malignant tumors as compared with FDG-PET. [3][4][5] In the present study, we compared the diagnostic ability of FMT-PET and FDG-PET for the diagnosis of maxillofacial tumors.…”