Mitsuyuki Miyakubo

Gunma University, Maebashi, Gunma, Japan

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Publications (13)16.34 Total impact

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    ABSTRACT: 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.
    No preview · Article · Oct 2010 · Annals of Nuclear Medicine
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    ABSTRACT: 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 (p< 0.01). 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%, p < 0.01; Follow up: 97.2% vs. 74.4%, p < 0.01). In Fisher's direct probability test, a significant difference was noted in the sensitivity (Initial staging: 91.3% vs. 87.0%, p < 0.01; Follow up: 93.9% vs. 91.4%, p <0.01). 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.
    Preview · Article · Feb 2010 · Annals of Nuclear Medicine
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    ABSTRACT: Background: It is still controversial whether FDG uptake is correlated with cellular proliferation and prognosis of oral squamous cell carcinoma(OSC). In this study,we performed PET study and immunohistochemical analysis to elucidate the relationship between FDG uptake and expression of cellular proliferative markers and pathological prognostic markers in patients with OSC. Methods: FDG PET and immunohistochemical staining have been carried out in sixteen patients with OSC. Tumor uptake of FDG was expressed with standardized uptake value (SUV). The expression of Ki-67, Topoisomerase IIα(Topo IIα), p53, and p63 in cancer cells was quantitatively assessed with positivity of the immunohistochemical staining. SUV was compared with the results of immunohistochemical analysis. Results: FDG PET study revealed that SUV ranged from 3.6 to 22.1 with average of 10.4. Average positive rate of Ki-67,Topo IIα, p53, and p63 was 68.9%, 58.9%, 72.0%, and 65.2%, respectively. Pearson productmoment correlation coefficient analysis revealed that SUV was significantly correlated with Ki-67 (r = 0.616, p=0.01), Topo IIα (r=0.677, p=0.004), p53 (r=0.613, p=0.01), and p63 (r=0.710, p=0.002), respectively. Conclusion: The present preliminary study indicated that FDG uptake was closely correlated with pathological cellular proliferative and prognostic markers in patients with OSC.
    No preview · Article · Jan 2009 · The Kitakanto Medical Journal
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    ABSTRACT: Aims: The treatment of oral malignant tumors cause not only disorders of essential functions such as swallowing, articulation and respiration, but aesthetic disorder of face showing personal identity. Therefore, more stable and qualitative treatment is demanded for oral malignant tumors. The aim of the present study is to analyze the treatment of oral malignant tumors. Subjects and methods: A clinico-statistical investigation was carried out with 46 oral malignant tumor patients in the Department of Oral and Maxillofacial Surgery. Gunma University Hospital between January 2001 and December 2003. Results: The most common age group of the patients was 60-69, which accounted for 39.1% of all patients, and the frequency of senior patients aged 50-79 accounted for 82.5%. The primary tumors in tongue (16; 34.7%) and in maxillary and mandibular gingiva (22; 47.7%) were most common. Forty patients (86.9%) were diagnosed squamous cell carcinoma (SCC) pathologically. In the staging of the patients with SCC, stage II cases (17; 42.5%) were most frequency. The treatment strategy for oral SCC consisted of surgery mainly, and of adjuvant radio/chemo therapy. The 5-year cumulative survival rate for oral SCC was 71.0% in all cases, 80.0% in stage I , 85.0% in stage II, 57.0% in stage III and 33.0% in stage IV. Conclusions: Because of the tendency for the oral malignant tumors to increase in senior patients, it is thought to be important for the treatment strategy to consider the general condition and complication of the patients.
    No preview · Article · May 2008 · The Kitakanto Medical Journal
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    ABSTRACT: We report the results of (18)F-fluorodeoxyglucose positron emission tomography (FDG PET) and immunohistochemical staining of glucose transporter 1 (Glut-1) and hexokinase II (HK-II) in patients with hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCC) to observe the variation in (18)F-FDG uptake and variation in expression of Glut-1 and HK-II in these hepatic tumors. In the case of HCC, moderate (18)F-FDG uptake and strong expression of HK-II were detected, whereas Glut-1 was not expressed. Conversely, CCC showed high (18)F-FDG uptake and increased expression of Glut-1 but HK-II was not expressed. The variation in the (18)F-FDG uptake and expression of Glut 1 and HK-II in HCC and CCC might be owing to the difference in origin and the different mechanisms involved in glucose uptake, rate of glucose transporters, and hexokinase activity involved in the glycolytic pathway.
    No preview · Article · Feb 2008 · Annals of Nuclear Medicine
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    ABSTRACT: The aim of this study was to evaluate the role of positron emission tomography (PET) with 18F-fluoro-2-deoxy-D-glucose (18F-FDG) in the restaging of hepatocellular carcinoma (HCC) treated with radiofrequency ablation (RFA). This study was performed on 33 lesions in 24 patients with HCC. 18F-FDG PET and computed tomography (CT) studies were performed in all patients before treatment. PET acquisition was started 50-60 min after injection of 18F-FDG (5-6 MBq/kg). Semi-quantitative analysis using Standardized Uptake Value (SUV) was measured for the evaluation of tumour 18F-FDG uptake. All patients underwent RFA treatment and were followed up at least 2 years with 18F-FDG PET, CT and clinical evaluation in the interval of every 3 months in the first year and every 6 months in the second year. 18F-FDG PET detected recurrence earlier than CT between 4-6 months in 2 patients and between 7-9 months in 6 patients whereas CT was positive in 4 patients. Overall detection rate of recurrence with 18F-FDG PET was 92% which was higher than that of CT (75%). Statistically significant difference in the SUV was observed between well and moderately differentiated HCC (p=0.033) and also between well and poorly differentiated HCC (p=0.037). The size of tumours showed a significant correlation with the time of recurrence (p<0.00033, r=0.8601, n=12). The results of this study indicate that 18F-FDG PET could detect recurrence earlier in patients with HCC treated with RFA, as compared with CT and could diagnose extrahepatic lesions. SUV showed a significant correlation with time of recurrence after RFA. 18F-FDG PET may be a dominant imaging modality as a follow-up procedure of HCC after RFA, in terms of early detection of recurrence.
    Preview · Article · Dec 2007 · Oncology Reports
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    ABSTRACT: 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.
    Full-text · Article · Feb 2007 · Annals of Nuclear Medicine
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    ABSTRACT: To compare L-3-[18F]-fluoro-a-methyltyrosine (FMT)-positron emission tomography (PET) and 2-[18F]-fluoro-2-deoxy-D-glucose (FDG)-PET in the differential diagnosis of maxillofacial tumors. 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). 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.
    Full-text · Article · Feb 2007 · Annals of Nuclear Medicine
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    ABSTRACT: Positron emission tomography (PET) has emerged as a significant molecular imaging technique in clinical oncology and cancer research. PET with (18)F-fluorodeoxyglucose ((18)F-FDG) demonstrates elevated glucose consumption by tumor cells, and is used clinically for the accurate staging and restaging of cancer, planning of radiotherapy, and predicting response or lack of response in the early stages of treatment. Combined PET and computed tomography (PET-CT) provides both functional and morphological information of the disease to allow accurate diagnosis of cancer. PET with new radiotracers such as protein synthesis markers and proliferation markers, as well as hypoxia and receptor-binding agents, will offer patient-specific images in order to yield tailored diagnostic and prognostic information.
    Preview · Article · Jan 2007 · Cancer Science
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    ABSTRACT: Positron emission tomography (PET) using 2-(18)F-fluoro-2-deoxy-D-glucose (FDG), a radioactive derivative of glucose, is an advanced imaging tool, based on the increased glucose consumption of cancer cells. FDG-PET provides information that is not obtainable with other imaging modalities, and is very effective in the diagnosis and management of patients with various types of cancers. However, there are some limitations, such as low FDG uptake in some cancers, substantial FDG uptake in inflammatory cells, and the lack of anatomical information and poor imaging quality of PET. A recently developed integrated PET/computed tomography (CT) system, which combines a PET camera and CT scanner in a single session, has overcome these drawbacks by providing both anatomical and functional imaging at the same position. PET and/or PET/CT using FDG is clinically useful in the detection of cancer, the differentiation of malignant and benign lesions, the staging of cancer before therapy, and the assessment of cancer therapy, as well as for determining the recurrence after therapy of most cancers, including lung cancer, gastrointestinal cancer, breast cancer, and malignant lymphoma. PET/CT has become the new standard approach to imaging in the diagnosis and management of many cancer patients.
    No preview · Article · Sep 2006 · International Journal of Clinical Oncology
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    ABSTRACT: Background and Aims: Sentinel lymph node navigation is expected to reduce the need for lymph node dissection in cancer surgery. We studied whether the sentinel lymph node concept is applicable to oral cancer. Patients and methods: Subjects were 7 patients with oral squamous cell carcinoma undergoing primary resection and neck dissection between April 2002 and July 2003. They were injected with 99mTc labeled phytate surrounding primary lesion for tracers preoperatively. Preoperative lymphoscintigraphy and intraoperative identification by gamma probe were done to detect sentinel lymph nodes. Dissected lymph nodes were examined histopathollogically and nuclearadiologically. Results: Sentinel lymph nodes were recognized at the submandibular region in all patients, and additional nodes at the cervical region in 3 cases. Metastatases were identified in 3 cases, one of whom had multiple metastases downstream from the sentinel lymph node. Another had further metastasis outside the dissection area. Conclusion: Sentinel lymph nodes are detected as described above and the sentinel lymph node concept is reasonable for oral cancer application.
    No preview · Article · May 2005 · The Kitakanto Medical Journal
  • T. Higuchi · N. Oriuchi · M. Miyakubo · H. Otake · K. Matsubara · N. Khan · M. Tian · K. Endo
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    ABSTRACT: Objectives: Evaluation of the usefulness of FDG-PET in the diagnosis of diffuse pulmonary involvement of malignant lymphoma. Patients and methods: Two cases with suspected diffuse pulmonary involvement of lymphoma have undergone FDG-PET study before and after chemotherapy such as CHOP (Cyclophosphamide, Doxorubicin, vincristin and predonisolone) therapy. After overnight fasting, 6 MBq/kg of FDG was intravenously injected followed by whole body PET scan. After image reconstruction, abnormal FDG uptake in the lung lesion was visually independently evaluated by two nuclear physicians, and quantitative evaluation using standardized uptake value (SUV) was also added. Results: Diffuse pulmonary uptake mainly located in the dorsal lung field has been noted in two cases. SUV in these lesions was 2.5 and 1.5, respectively. After chemotherapy using CHOP, those abnormal FDG uptakes have disappeared and serum tumor marker (LDH and s-IL2 receptor) have decreased. These findings seemed to indicate the therapeutic effect to diffuse pulmonary involvement of lymphoma. Conclusion: FDG-PET seems to be useful in the initial evaluation of diffuse pulmonary involvement of lymphoma and also in monitoring therapeutic effect, because these lesions are sometimes missed by conventional chest plain X-ray or computed tomography (CT).
    No preview · Article · Mar 2004 · International Congress Series

  • No preview · Article · Jan 2004 · Japanese Journal of Head and Neck Cancer

Publication Stats

227 Citations
16.34 Total Impact Points

Institutions

  • 2008-2010
    • Gunma University
      • Department of Stomatology and Maxillofacial Surgery
      Maebashi, Gunma, Japan