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Objective L-3-[18F]-fluoro-α-methyl tyrosine (18F-FAMT) is an amino acid tracer for positron emission tomography/computed tomography (PET/CT) which specifically transported into cancer cells by L-type amino acid transporter 1 (LAT1). LAT1 overexpression in tumors is significantly correlated with cell proliferation and angiogenesis. 18F-FAMT PET/CT, fluorine-18-fluorodeoxyglucose (18F-FDG) PET/CT and magnetic resonance imaging (MRI) were compared for their diagnostic performance in the detection of bone marrow invasion in patients with oral squamous cell carcinoma (OSCC).

Objective l-3-[18F]-fluoro-α-methyl tyrosine (FAMT) is transported into cancer cells by l-type amino acid transporter 1 (LAT1). The purpose of the present study is to correlate the uptake of FAMT and FDG with the cellular proliferative activity measured by the Ki-67 labeling index (Ki-67 LI) in oral squamous cell carcinoma (OSCC).

Clinical application of FDG-PET in head and neck cancer includes identification of metastases, unknown primary head and neck malignancy, or second primary carcinoma, and also recurrent tumor after treatment. In this study, the additional value of PET/CT fusion images over PET images alone was evaluated in patients with initial staging and follow up of head and neck malignancy.Forty patients with suspected primary head and neck malignancy and 129 patients with suspected relapse after treatment of head and neck malignancy were included. FDG-PET/CT study was performed after the intravenous administration of FDG (5 MBq/kg). Target of evaluation was set at primary tumor, cervical lymph node, and whole body. PET images and PET with CT fusion images were compared. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Results of PET and PET/CT were compared with postoperative histopathological examination, and case by case comparison of PET and PET/CT results for each region was performed. The additional value of CT images over PET only images was assessed. Statistical differences in sensitivity and specificity were evaluated.In the comparative evaluation of 507 targets by PET alone and PET/CT, 401 targets showed agreement of the results. Of the 106 discordant targets, 103 showed a positive result on PET alone and negative result on PET/CT. These results showed a significant difference (p0.01). Sensitivity of PET/CT was slightly higher than that of PET without statistical significance, while specificity of PET/CT was significantly higher than that of PET alone (Initial staging: 90.5% vs. 62.2%, p0.01; Follow up: 97.2% vs. 74.4%, p0.01). In Fisher's direct probability test, a significant difference was noted in the sensitivity (Initial staging: 91.3% vs. 87.0%, p0.01; Follow up: 93.9% vs. 91.4%, p0.01).Combined PET/CT showed improved diagnostic performance than PET alone by decreasing the number of false positive findings in patients with initial staging and follow up of head and neck malignancy.

Objectives: To comparel-3-[18F]-fluoro-α-methyltyrosine (FMT)-positron emission tomography (PET) and 2-[18F]-fluoro-2-deoxy-d-glucose (FDG)-PET in the differential diagnosis of maxillofacial tumors.Methods: This study included 36 patients (16 males, 20 females; 31–90 years old) with untreated malignant tumors (34 squamous cell carcinoma, one mucoepidermoid carcinoma, one rhabdomyosarcoma) and seven patients (five males, two females; 32–81 years old) with benign lesions. In all patients, both FMT-PET and FDG-PET were performed within two weeks before biopsy or treatment of the lesions. To evaluate the diagnostic usefulness of FMT-PET and FDG-PET, visual interpretation and semiquantitative analysis were performed. PET images were rated according to the contrast of tumor uptake as compared with background, and were statistically analyzed. As a semiquantitative analysis, standardized uptake values (SUV) of the primary tumors were measured, and the SUV data were analyzed using receiver operating characteristic (ROC) curves.Results: The mean SUV of the malignant lesions were significantly higher than those of the benign lesions in both FMT-PET (2.62±1.58 vs. 1.20±0.30, p

L-3-[(18)F]-fluoro-α-methyl tyrosine ((18)F-FAMT) is an amino acid tracer for positron emission tomography/computed tomography (PET/CT) which specifically transported into cancer cells by L-type amino acid transporter 1 (LAT1). LAT1 overexpression in tumors is significantly correlated with cell proliferation and angiogenesis. (18)F-FAMT PET/CT, fluorine-18-fluorodeoxyglucose ((18)F-FDG) PET/CT and magnetic resonance imaging (MRI) were compared for their diagnostic performance in the detection of bone marrow invasion in patients with oral squamous cell carcinoma (OSCC).Twenty-seven patients with OSCC on the upper or lower alveolar ridge underwent staging by MRI, (18)F-FDG PET/CT and (18)F-FAMT PET/CT studies before surgery. Post-surgical pathologic examination was used as the standard to determine the final diagnoses. The possibility of bone marrow invasion on MRI, (18)F-FDG PET/CT and (18)F-FAMT PET/CT were usually graded retrospectively into five-point score. Sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were calculated according to the obtained scores.As the sensitivity of (18)F-FDG PET/CT was highest (100 %) among that of MRI (95 %) and (18)F-FAMT PET/CT (90 %), the specificity of (18)F-FAMT PET/CT was highest (85.7 %) among that of MRI (57 %) and (18)F-FDG PET/CT (14.3 %). The size of pathological tumor was accorded with that detected by (18)F-FAMT PET/CT and was smaller than that detected by (18)F-FDG PET/CT (P0.01). Significant difference was not found between (18)F-FAMT PET tumor volume and pathological tumor volume.(18)F-FAMT PET/CT was useful and more specific than MRI or (18)F-FDG PET/CT in the detection of bone marrow invasion of OSCC and may contribute to minimize the extent of resection in oral surgery patient.

L-3-[¹⁸F]-fluoro-α-methyl tyrosine (FAMT) is transported into cancer cells by L: -type amino acid transporter 1 (LAT1). The purpose of the present study is to correlate the uptake of FAMT and FDG with the cellular proliferative activity measured by the Ki-67 labeling index (Ki-67 LI) in oral squamous cell carcinoma (OSCC).Twenty-five patients with OSCC were enrolled in this study. Both FAMT-PET and FDG-PET were performed within 4 weeks before surgery in all cases. The uptake of FAMT and FDG was compared by semiquantitative analysis with maximal standardized uptake values (SUVmax) of the primary tumors. Ki-67 LI of the tumors was analyzed by immunohistochemical staining and correlated with the clinicopathologic variables and the uptake of PET tracers.For primary tumor detection, FAMT-PET exhibited a sensitivity of 84%, whereas that of FDG-PET was 88%. In all visible lesions, mean FDG uptake determined by average SUVmax was 9.7 (range 4.2-15.9) and mean FAMT uptake was 3.5 (range 1.3-8.5). The SUVmax of FAMT tended to show a better correlation with Ki-67 LI (r = 0.878) than that of FDG (r = 0.643).Uptake of FAMT correlated with cellular proliferation of OSCC. FAMT-PET may be a useful procedure to evaluate tumor proliferation of OSCC.

Objective: The aim of this study is to clarify the clinical utility of 2-deoxy-2-[18F]fluoro-d-glucose (FDG) positron emission tomography (PET) in determining the TNM classification in patients with oral cancer.Methods: Twenty-five consecutive patients (14 male and 11 female; age range, 40 yr to 86 yr) with oral cancer were included in this study. The diagnostic accuracy for detecting cervical lymph nodes was investigated by comparing the results of CT and/or MRI and physical findings. For the semi-quantitative analysis, the tumor standardized uptake value (SUV) and tumor to background SUV ratio (T/B ratio) were assessed in primary tumors and cervical lymph nodes.Results: All primary lesions were visualized on FDG-PET images. Even though artifacts from dental materials near the lesion hampered the delineation of primary tumors on CT/MRI, the extent of primary tumors was accurately assessed by FDG-PET. The SUV and T/B ratio in the primary tumor classified in higher T grade (T3 and T4) was significantly higher than that in lower T grade (T1 and T2) (mean ± SD of SUV; 8.32±2.99 vs. 5.15±3.77, p