Hideo Kamada

Positron emission tomographic imaging with 11C-choline in differential diagnosis of head and neck tumors : comparison with 18F-FDG PET

The aim of this study was to evaluate the clinical value of positron emission tomography (PET) with11C-labeled choline (CHOL) for the differential diagnosis of malignant head and neck tumors from benign lesions as compared with18F-fluorodeoxyglucose PET.Methods: We studied 45 patients (28 males, 17 females, age range, 29-84 years) with suspected lesions in the head and neck region using both CHOL and FDG PET within a 2-week period on each patient. All patients fasted for at least 6 hours for both the CHOL and FDG studies. PET imaging was performed 5 min and 50-60 min after intravenous injection of CHOL and FDG, respectively. After data acquisition, PET images were corrected for attenuation, and the reconstructed images were analyzed by visual interpretation. Then, the standardized uptake value (SUV) was calculated for semiquantitative evaluation of tumor tracer uptake. Finally the results of PET scans were compared with the histological diagnoses from surgical specimens or biopsies.Results: With CHOL PET, malignant tumors were correctly detected in 24 (96%) of 25 patients, and benign lesions in 14 (70%) of 20 patients with an accuracy of 84.4%. With FDG PET, malignancy was correctly diagnosed in 23 (92%) of 25 patients, and benign lesions in 13 (65%) of 20 patients resulting an accuracy of 80%. A significant positive correlation between CHOL and FDG SUVs was found for all lesions (r = 0.677, p = 0.004, n = 45). Malignant tumors showed significantly higher tracer accumulation than the benign lesions in both CHOL and FDG studies (5.69 ± 1.61, n = 25 vs. 2.98 ± 2.13, n = 20, p < 0.0001; 9.21 ± 4.23, n = 25 vs. 3.60 ± 2.57, n = 20, p < 0.0001). The cutoff SUV for differentiating malignant and benign lesions was 3.5 for CHOL and 3.9 for FDG. CHOL showed slightly better differentiation between malignant and benign lesions than FDG although some overlap existed on both studies. But the difference was not statistically significant.Conclusion: The results of this study indicate that CHOL PET may be feasible clinically for head and neck tumor imaging. PET imaging with CHOL seems to be able to detect malignant head and neck tumors as effectively as FDG PET. The advantages of CHOL PET were shorter examination period and low uptake in the muscle. However, both CHOL and FDG have some limitations in the evaluation of salivary gland lesions.

A preliminary study on sentinel lymph node biopsy: feasibility and predictive ability in oral cavity cancer.

The main factor that affects the prognosis of patients with head and neck cancer (HNC) is regional lymph node metastases. For this reason, the accurate evaluation of neck metastases is required for neck management. This study investigates the sentinel lymph node identification and the accuracy of the histopathology of the sentinel lymph node in patients with HNC. Eleven patients with histologically proven oral squamous cell carcinoma accessible to radiocolloid injection were enrolled in this study. Using both lymphoscintigraphy and a handheld gamma probe, the sentinel lymph node could be identified in all 11 patients. Subsequently, the sentinel lymph nodes and the neck dissection specimen were examined for lymph node involvement due to tumor. The histopathology of sentinel lymph nodes was consistent with the pathological N classification in all 11 patients. Furthermore, the histopathology of sentinel lymph nodes was superior to physical examination, computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) scan. The results of this study indicate that sentinel lymph node identi-fication is technically feasible and predicts cervical metastases in patients with oral cavity cancer. This may be a useful diagnostic technique for identifying lymph node disease in staging lymph node dissection.

Diagnosis of tumor in the nasal cavity and paranasal sinuses with [11C]choline PET: Comparative study with 2-[18F]fluoro-2-deoxy-d-glucose (FDG) PET

Abstract[11C]choline (11C-choline) positron emission tomography (PET) was performed to evaluate its clinical utility in the diagnosis of tumors in the nasal cavity and paranasal sinuses. We studied 22 patients with suspicion of malignant tumors in the nasal cavity and paranasal sinuses. Tumor uptake of11C-choline was measured with standardized uptake value (SUV) and correlated with the pathological diagnosis. 2-[18F]fluoro-2-deoxy-d-glucose (FDG) PET was performed in all patients for comparison. Both11C-choline and FDG PET depicted squamous cell carcinoma showing an increased activity significantly higher than that of normal tissue, and these SUVs were significantly higher than those of benign lesions. FDG uptake in malignant tumors as a whole was variable. Although11C-choline uptake in squamous cell carcinoma was lower than FDG uptake,11C-choline uptake in malignant tumors was relatively uniform and statistical significance was found. PET with11C-choline may be useful to diagnosis tumors in the nasal cavity and paranasal sinuses.

Vertigo secondary to hypotension: the relationship between therapeutic effects and hearing

Patients with vertebrobasilar insufficiency tend to develop transient, repeated vertigo. However, diagnostic criteria by which to definitively diagnose circulatory disturbance of the vertebrobasilar system have yet to be established. Thus, in order to determine such criteria the relationship between the therapeutic effects on clinical symptoms and hearing in 40 patients with vertigo secondary to hypotension were investigated in the present study. In most patients, vertigo was perceived as a floating or spinning sensation which occurred spontaneously or during positional changes and lasted for a short period of time without hearing disturbance. Audiometry revealed bilateral low-frequency hearing loss or a tendency to low-frequency hearing loss in all patients. Low-frequency hearing loss is an important audiometric indication of vertebrobasilar insufficiency. Such hearing loss is very responsive to therapeutic circulatory agents and is considered to be an index for the evaluation of the effects of treatment for vertebrobasilar insufficiency.

Development of a new method using narrow band imaging for taste assessment.

The observation of fungiform papillae is a useful objective taste examination. The purpose of this study is to develop a new method using narrow band imaging for assessment of taste function.

Migrainous Vertigo Treated Successfully with Nitroglycerin in Three Cases

1. ニトログリセリンが有効であった片頭痛性めまいの3症例につき報告した.2. 片頭痛は全例 classic migraine であり, めまいは回転性めまい2例, 浮動性めまい1例であった.3. めまいは全例, 片頭痛の遅発性合併症であった.4. 発作初期本剤の半～1錠 (0.15～0.3mg) の舌下服用で, めまい発作は全例で抑制ないし頓挫し, 頭痛発作の抑制にも有効であった.