Utilidad de 11C-metionina PET/CT en neurooncología / Utility of 11C-methionine PET/CT in neuro-oncology

La tomografía por emisión de positrones con metionina carbono 11 (11C-metionina PET/TC) se utiliza en la evaluación de los tumores primarios del sistema nervioso central. Describimos nuestra experiencia sobre los primeros 4 pacientes con tumores de la serie glial estudiados con 11C-metionina PET/TC. Este es un estudio descriptivo, observacional y prospectivo. Se presentan 4 pacientes entre 38-50 años de edad con diagnóstico de gliomas (clasificación de la OMS). A todos se les realizó RM y 11C-metionina PET/TC para evaluar actividad tumoral y diferenciar progresión tumoral de pseudoprogresión. Caso 1, gliomatosis cerebri grado II posradioterapia. Caso 2, glioblastoma grado IV postratamiento RT + temozolomida. Caso 3, oligodendroglioma grado II posradioterapia en 1993. Caso 4, oligoastrocitoma anaplásico grado III postratamiento RT + temozolomida. El patrón de captación de la 11C-metionina comparativamente con la RM, demostró progresión tumoral en los casos 1, 3 y 4; en el caso 2 mostró captación aunque el diagnóstico final fue pseudoprogresión. A diferencia del PET con 18fluordeoxiglucosa, la captación de 11C-metionina en el tejido cerebral normal y en la pseudoprogresión es baja, y los gliomas se visualizan como áreas metabólicamente activas. En los casos presentados, el 11C-metionina PET/TC proveyó información valiosa sobre el comportamiento y extensión de la lesión, aunque en uno de los casos presentados no diferenció progresión tumoral de pseudoprogresión. El 11C-metionina PET/TC sería una herramienta útil en el estudio y seguimiento de los pacientes con gliomas.

Positron emission tomography (PET) with 11C-methionine (11C-methionine PET/CT) is a new technique used to evaluate primary central nervous system (CNS) tumors. We describe our experience regarding the first 4 patients with glial tumors and 11C-methionine PET/CT. This is a descriptive, observational and prospective study of 4 patients between 38-50 years of age, with different gliomas (WHO classification). MRI and 11C-methionine PET/CT were performed in all cases. Case 1, gliomatosis cerebri grade II post-radiotherapy. Case 2, oligodendroglioma grade II diagnosed and treated with radiotherapy in 1993. Case 3, glioblastoma grade IV post-radiotherapy + temozolomide. Case 4, anaplastic oligoastrocytoma grade III post-radiotherapy + temozolomide. The pattern of 11C-methionine uptake compared with MRI showed tumor progression in cases 1, 3 and 4, and in case 2 showed uptake although the final diagnosis was pseudoprogression. Unlike 18fluordeoxiglucose PET/TC, 11C-methionine uptake in normal brain tissue and pseudoprogression is low, and gliomas are displayed as metabolically active areas. The 11C-methionine PET/CT provided valuable information on the tumoral behavior and extension, although in one case presented did not differentiate tumor progression from pseudoprogression. 11C-methionine PET/CT could be a useful tool in the study and follow-up to patients with gliomas.

Relation of 11 C-MET uptake in PET with cell proliferation and angiogenesis in human brain gliomas / 重庆医学

Objective To investigate the relation of 11C-methionine (11C-MET) uptake with cell proliferation and angiogenesis in human brain gliomas .Methods For 30 cases of newly diagnosed glioma patients ,positron emission tomography (PET ) examina-tion with 11C-MET was performed ,and the maximal standardized uptake value (SUVmax) of 11C-MET was measured .Expression of Ki-67 and CD34 antigens was examined by immunohistochemistry method in the same glioma samples ,both Ki-67 labeling index (Ki-67 LI) and microvessel density (MVD) were measured .Results Both 11C-MET SUVmax and Ki-67 LI increased significantly with glioma pathological grade ascending (P=0 .000 ,P=0 .000) ,and which in malignant glioma tissues were significantly higher than those in benign glioma tissues as well (P=0 .000 ,P=0 .000);however ,there were not significant differences in MVD among different grades of gliomas (P=0 .831) as well as between high and low malignant gliomas (P=0 .370) .11 C-MET SUVmax was significantly positively correlated with Ki-67 LI (P= 0 .000) ,however ,there were not significant correlations between 11C-MET SUVmax and MVD (P=0 .154) as well as between Ki-67 LI and MVD (P=0 .842) .Conclusion 11C-MET uptake and cell prolif-eration activity can better reflect the pathological grades and malignant degrees of gliomas .

A Case of Basal Ganglia Germinoma Presenting Only with Cerebral Hemiatrophy Diagnosed by Using 11C-Methionine Positron Emission Tomography / 대한소아신경학회지

We present a case of cerebral germinoma that occurred in the basal ganglia with progressive hemiparesis. A 10-year-old boy was referred to our hospital complaining of progressive right hemiparesis and decreased mental functions. Brain MRI showed left cerebral hemiatrophy and high signal intensity in left thalamus, basal ganglia, cerebral peduncle, and pons. However, no mass or enhancement was observed. 11C-Methionine positron emission tomography showed discernable hot uptake in the left basal ganglia and thalamus. Stereotactic biopsy, with a guide of 11C-Methionine positron emission tomography, was performed and the diagnosis of pure germ cell tumor was determined. 11C-Methionine positron emission tomography is useful for localization of a suspicious tumor in patients with cerebral hemiatrophy without overt mass or enhancing lesions in brain MRI.