carbon-11-methionine and Germinoma

The purpose of this study was to investigate the value of C-11 methionine (MET) positron emission tomography (PET)/computed tomography (CT) in patients with intracranial germinoma (IG).. We conducted a retrospective analysis of 21 consecutive patients with pathologically confirmed IGs and eight patients with intracranial non-germinomas (INGs) located in a similar region. Clinical characteristics, imaging findings, and tumor markers such as α-fetoprotein (AFP) and β-human chorionic gonadotropin (HCG) were used as clinical variables. Maximum standardized uptake value (SUVmax), tumor-to-normal tissue (T/N) ratio, and visual scoring of tumor were used as MET PET parameters.. All IGs were well visualized on MET PET with a three-grade visual scoring system. In addition, SUVmax of IGs was higher than that of INGs (P = 0.005). Pre-treatment (Pre-Tx) T/N ratio was significantly correlated with pre-Tx serum HCG (P = 0.031). Moreover, MET PET parameters showed significant associations with tumor location, sex, KRAS variant, and symptoms.. MET PET/CT could be a useful diagnostic tool in patients suspected of having IGs. In addition, the MET avidity of tumor is a potential surrogate biomarker of HCG, which has been used as a diagnostic marker for IGs. Tumor MET parameters also had significant differences according to tumor locations, sex, symptoms, and KRAS mutation. However, MET avidity of tumors had no significant prognostic value.

Topics: Adolescent; Adult; alpha-Fetoproteins; Biomarkers, Tumor; Brain Neoplasms; Child; Chorionic Gonadotropin, beta Subunit, Human; Female; Germinoma; Humans; Male; Methionine; Positron Emission Tomography Computed Tomography; Predictive Value of Tests; Prognosis; Retrospective Studies; Survival Analysis; Young Adult

We herein describe a 12-year-old male patient with a germinoma of the basal ganglia who presented with progressive hemiparesis. MR imaging showed ipsilateral cerebral hemiatrophy predominantly in the left basal ganglia, whereas no mass or enhancement was depicted. Single photon emission CT revealed no significant uptake of thallium, whereas (11)C-methionine positron emission tomography showed clearly discernible uptake in the left putamen. Stereotactic biopsy, referencing the results of (11)C-methionine positron emission tomography, was performed, allowing histologic verification of germinoma to be established. (11)C-methionine positron emission tomography was the only technique that indicated the precise localization of the tumor in our patient and enabled biopsy-based final diagnosis of the basal ganglia germinoma without any overt mass formation.

Topics: Atrophy; Basal Ganglia; Brain; Brain Neoplasms; Carbon Radioisotopes; Child; Germinoma; Humans; Magnetic Resonance Imaging; Male; Methionine; Paresis; Radiopharmaceuticals; Tomography, Emission-Computed; Tomography, X-Ray Computed