Yoshiki Nakasone

Expression of Glut-1 and Glut-3 in untreated oral squamous cell carcinoma compared with FDG accumulation in a PET study.

Increased expression of glucose transporter-1 (Glut-1) and glucose transporter-3 (Glut-3) has been reported in many human cancers. The mechanism of glucose entry into oral squamous cell carcinoma (OSCC) remains unclear. In this study we investigated, in untreated human OSCC, the relationship between tumour fluorine-18 fluoro-2-deoxy-d-glucose (FDG) accumulation and the expression of Glut-1 and Glut-3, as well as the association between the expression of Glut-1 and of Glut-3. All patients underwent FDG positron emission tomography (PET) pre-operatively. Standardised uptake values (SUVs) were used for evaluation of tumour FDG uptake. Final diagnoses were established by histology. Immunohistochemical staining results were evaluated according to the percentage (%) of positive area, intensity and staining score. Tumour sections were stained by immunohistochemistry for Glut-1 and Glut-3. Glut-1 immunostaining revealed that 18 (94.7%) of the 19 tumours stained positively, while Glut-3 immunostaining yielded positive findings for 16 (84.2%) tumours. Overall, a relatively low level of agreement (36.8%) in the staining score was observed between Glut-1 and Glut-3 expression. No relationship was found between the staining pattern and tumour differentiation or T grade classification in either Glut-1 or Glut-3 immunostaining. Furthermore, no relationship was found between increased FDG SUV and tumour differentiation, but the former did correlate with T grade. In conclusion, high FDG uptake values were seen in OSCC with overexpression of Glut-1 and Glut-3. However, no significant correlation was found between FDG SUV and Glut-1 or Glut-3 expression.

The role of whole-body FDG-PET in preoperative assessment of tumor staging in oral cancers.

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<0.01, mean ± SD of T/B ratio; 6.96±3.23 vs. 3.61±2.76, p<0.01). The SUV and T/B ratio of metastatic lymph nodes were also significantly higher than those of normal lymph nodes (mean ± SD of SUV; 3.39±1.69 vs. 1.55±0.57, p<0.001, mean ± SD of T/B ratio; 2.46±1.08 vs. 1.03±0.22, p<0.001). Among these three methods, FDG-PET in conjunction with CT/MRI showed the highest accuracy of 92%, but there were no significant differences in diagnostic accuracy among the three methods. For the semiquantitative analysis, a threshold SUV of 2.0 provided 100% sensitivity, 82% specificity, and 88% accuracy. Furthermore, a threshold T/B ratio of 1.5 provided 100% sensitivity, 100% specificity, and 100% accuracy. Regarding the detection of distant metastasis, there was one positive result in FDG-PET showing distant pulmonary metastasis.Conclusions: Whole-body FDG-PET is an effective and convenient diagnostic tool for the evaluation of tumor staging in patients with oral cancer. Tumor staging by whole-body FDG-PET may, in fact, supplement the conventional staging by means of CT/MRI and physical findings.

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

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<0.01) and FDG-PET (9.17±5.06 vs. 3.14±1.34, p<0.01). A positive correlation (r=0.567, p<0.0001, n=46) was noted between FMT and FDG. ROC analysis revealed that there was no statistically significant difference in SUVs between FMT and FDG for differentiating malignant tumors. In 27 of 36 patients, FMT-PET had better contrast of malignant tumor visualization to the surrounding normal structures by visual assessment (p<0.005, binomial proportion test).Conclusions: Differential diagnosis of FMT-PET based on the uptake in maxillofacial tumors is equivalent to FDG-PET. However, the contrast of FMT uptake between maxillofacial tumors and the surrounding normal structures is higher than that of FDG, indicating the possibility of accurate diagnosis of maxillofacial tumors by FMT-PET.

Hexokinase-II expression in untreated oral squamous cell carcinoma: Comparison with FDG PET imaging

Hexokinase is thought to be one of the key factors of glucose catabolism in the cell. The aim of this study was to investigate the relationship between HK-II expression and18F-fluoro-2-deoxy-D-glucose (FDG) uptake in human untreated oral squamous cell carcinoma (OSCC). Pre-operatively FDG positron emission tomography (PET) was performed 60 min after FDG injection in all the patients. Maximum standardized uptake value (SUV) was used for evaluation of tumor FDG uptake. Tumor sections were stained immunohistochemically for HK-II. All the tumor sections stained positive for HK-II. Eighteen (95%) tumors in HK-II showed immunostained positive area ≥50%. HK-II findings revealed eleven (58%) tumors with strong intensity, six (32%) with moderate intensity and two with weak intensity (10%). There was no statistically significant correlation between SUV and the expression of HK-II (p = 0.46). In conclusion, OSCC showed increased FDG accumulation and overexpression of HK-II. However, we did not find any significant relationship between high FDG uptake and overexpression of HK-II in this patient population, and thus other properties need to be evaluated in order to elucidate key factors responsible for FDG activity in OSCC.

Three dimensional position measurement for maxillofacial surgery by stereo X-ray images

This paper describes a method whereby a three dimensional position inside a human body can be measured using a simple X-ray stereo image pair. Because the geometry of X-ray imaging is similar to that of ordinary photography, a standard stereo vision technique can be used. However, one problem is that the X-ray source position is unknown and should be computed from the X-ray image. In addition, a reference coordinate on which the measurement is based needs to be determined. The proposed method solves these two problems using a cubic wire frame called the reference object. Although three dimensional positioning for a human body is possible by Computer Tomography (CT), it requires expensive equipment. In contrast, the proposed method only requires ordinary X-ray photography equipment, which is inexpensive and widely available even in developing countries.

Fibrous Dysplasia-like jaw Enlargement following Treatment with Growth Hormone

Abstract This report is of a 10-year-old boy with unusual fibrous dysplasia-like lesions in the jaw. The patient had been taking recombinant human growth hormone for the treatment of short stature due to growth hormone deficiency from the age of 8 to 10 years. The lesions were exceptionally large and affected the entire maxilla and mandible. An association with growth hormone therapy was suspected.

Mandibular Metastasis of a Bronchial Tumour

Abstract Mandibular metastatic tumours are uncommon and differential diagnosis is difficult. A 49-year-old man with a metastatic tumour of the mandible from a primary bronchial tumour is reported.