Koiku Yokoe

Kagawa University, Takaishi, Osaka-fu, Japan

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Publications (14)14.67 Total impact

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    ABSTRACT: (18)F-fluorodeoxyglucose (FDG) positron-emission tomography (PET) has been widely applied to malignant lymphoma both for initial staging and response evaluation. The objective is to compare the efficacy of the less common, but more easily implemented modality, CT, with that of FDG. We retrospectively reviewed consecutive patients diagnosed with malignant lymphoma in our hospital between October 2002 and March 2006, and compared the efficacy of FDG-PET and CT. The standard reference was defined by the pathology and clinical course of patients followed for more than 3 months. Thirty-three cases for staging and 62 cases for response evaluation after treatment were included. We calculated the sensitivity and specificity of each modality. The accuracy of the diagnostic modality was evaluated using receiver operating characteristic (ROC) analysis. The sensitivity and specificity of the initial staging were 87% and 100% on CT evaluation and 87% and 100% on FDG-PET, respectively. Sensitivity and specificity of the re-staging were 81% and 78% on CT evaluation and 82% and 97% on FDG-PET, respectively. The diagnostic accuracy of FDG-PET was comparable with that of CT both in initial staging and response evaluation. The maximum standardized uptake value was not associated with patient survival. In subgroup analysis, a tendency of lower sensitivity in the initial staging was found in FDG-PET for follicular lymphoma and CT for diffuse large B-cell lymphoma. Although different staging procedures appear better suited to certain subtypes of lymphoma, in general CT imaging might be as useful as FDG-PET in initial staging in selected patients.
    Internal Medicine 02/2009; 48(17):1509-13. · 0.97 Impact Factor
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    ABSTRACT: To assess the usefulness of SPECT images using (99m)Tc-Technegas (Technegas) and (133)Xe dynamic single photon emission computed tomography (SPECT) (Xe gas) and high-resolution computed tomography (HRCT), as compared with pathological assessment in the detection of small-airway disease including pulmonary emphysema. Seventeen patients with lung cancer were studied. All patients who had undergone both Technegas and Xe gas and CT prior to surgery were examined. SPECT and HRCT results were compared with the results of pathological findings. Histopathological analysis was performed in an area distant from cancer in lobectomy specimens obtained at surgery. Pathological analysis was performed in relation to bronchitis, bronchiolitis, fibrosis of the alveoli and disruption in walls of the alveoli. Pathological abnormality (mild-to-moderate abnormal change) was seen in all 17 cases. Three patients showed low attenuation areas on CT, and abnormal patterns in SPECT images. In 11 of 14 patients who showed normal findings on CT, SPECT imaging depicted abnormal findings. The remaining three patients had no abnormal findings on CT and both SPECT imaging. Technegas and (133)Xe SPECT imaging is useful for evaluating small-airway disease including pulmonary emphysema. Furthermore, SPECT imaging is more useful than morphological HRCT imaging in the evaluation of small-airway disease including pulmonary emphysema.
    Nuclear Medicine Communications 12/2006; 27(11):887-92. · 1.38 Impact Factor
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    ABSTRACT: Pyothorax-associated lymphoma (PAL) is a non-Hodgkin's lymphoma developing in the pleural cavity after a long-standing history of chronic pyothorax (CP). F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) imaging is a useful modality for determination of disease extent of various malignant tumors, including malignant lymphoma, but there have been no reports describing the usefulness of FDG-PET imaging in PAL. Here we report a case of PAL that relapsed after chemotherapy and was successfully treated by radiotherapy. FDG-PET imaging revealed that the tumor was localized to a soft-tissue attenuation mass behind the CP cavity in the right thorax, but did not infiltrate the CP cavity. A total dose of 40 Gy was administered to the area that included the PET-positive lesion, instead of including the entire CP cavity in the radiation field. Although computed tomography (CT) showed a residual mass, no FDG uptake was indicated by FDG-PET imaging performed just after the end of radiotherapy, and additional irradiation was not performed. No sign of relapse was found by FDG-PET imaging 3 months later. FDG-PET imaging was useful for both the planning of radiotherapy and assessing the treatment response of PAL.
    Annals of Nuclear Medicine 01/2006; 19(8):725-8. · 1.41 Impact Factor
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    ABSTRACT: Accurate baseline staging is necessary to appropriately treat pancreatic cancer. The present study was undertaken to evaluate the clinical contribution of whole body FDG-PET to the detection of distant metastasis in pancreatic cancer. A total of consecutive 42 patients with previously untreated pancreatic cancer were examined. Whole body FDG-PET imaging for initial staging was performed with a 3D acquisition and iterative reconstruction on Siemens ECAT HR+ scanner at 1 hour post 185-200 MBq 18F-FDG injection. PET findings were correlated with clinical and radiological data to determine the impact of PET on staging. In 16 patients, there were one or more sites of metastasis based on clinical data. FDG-PET correctly identified the presence of metastasis in 13 of 16 patients and its absence in 23 of the remaining 26 patients. Thus, FDG-PET missed 4 metastatic sites in 4 patients (liver and lung metastasis). FDG-PET correctly identified 8 metastatic sites in 7 patients (peritoneal dissemination and liver, bone and supraclavicular lymph node metastasis), which were missed on CT imaging. Based on whole body FDG-PET, the clinical stage was changed in 5 of 42 patients (11.9%). These results suggest that FDG-PET and CT appear to have a complementary role in the detection of distant metastasis in patients with pancreatic cancer.
    Annals of Nuclear Medicine 10/2005; 19(6):491-7. · 1.41 Impact Factor
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    ABSTRACT: The clinical efficacy and safety of hyperfractionated radiotherapy with concurrent chemotherapy were studied retrospectively in patients with primary advanced esophageal cancer. The subjects were 31 patients who were treated with hyperfractionated radiotherapy and concurrent chemotherapy in our institution between 1990 and 2001. The chemoradiotherapy consisted of cisplatin 70-80 mg/m2 on day one, and continuous infusion of 5-fluorouracil 700-800 mg/m2/24 hours on days 1 to 3, with concurrent hyperfractionated radiotherapy (57.6-72 Gy). Complete remission (CR) was observed in 17 cases, and partial response in 13 cases (response rate: 96. 7%). Three-year survival rate and 5-year survival rate were 35.5% and 26.3%, respectively. Grade 3/4 hematological toxicities included leukocytes in 7 patients (22.6%), hemoglobin in 6 patients (19.4%), and platelets in 4 patients (12.9%). Grade 3 dysphagia-esophageal related to radiation was observed in 3 patients (9.7%). Late toxicities occurred with the following incidences: hypothyroidism in 2 patients, benign esophageal strictures in 2 patients, pericardial effusion in 8 patients, and pleural effusion in 8 patients. The results suggest that combined chemotherapy and hyperfractionated radiotherapy is an effective and well-tolerated regimen.
    Gan to kagaku ryoho. Cancer & chemotherapy 10/2005; 32(9):1279-82.
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    ABSTRACT: Occult breast cancer presenting with axillary lymph node metastases is uncommon, and inflammatory breast cancer (IBC), as a subtype, is quite rare. Here we describe a case of IBC, which arose as an unknown primary carcinoma; the patient presented with axillary lymph node metastasis, and was successfully treated with trastuzumab and vinorelbine. Specifically, a 55-year-old woman presented with right axillary lymphadenopathy. Although she underwent various examinations, the primary site of the disease was not revealed. Axillary lymph node dissection was performed, and the lesion was diagnosed as a poorly differentiated adenocarcinoma. The patient chose to be treated by alternative medicine. About 6 months later, she was referred to our hospital, due to marked bilateral neck and axillary lymph node swelling. She presented with diffuse right breast enlargement, redness, and peau d'orange. Computed tomography (CT) of the breast showed skin thickening and swelling of the right breast.F-18 Fluorodeoxyglucose positron emission tomography (FDG-PET) showed FDG uptake in the right breast. The patient was clinically diagnosed with IBC. Because overexpression of the human epidermal growth factor receptor 2 (HER2) was found in the specimen from her right axillary lymph node, she was treated with trastuzumab and vinorelbine. Two months after the start of chemotherapy, CT revealed a complete response in the lymph nodes, and the skin thickening and parenchymal edema of the right breast had improved. FDG-PET was also performed at this time, and revealed no FDG uptake in either the right breast or the lymph nodes.
    International Journal of Clinical Oncology 09/2005; 10(4):285-8. · 1.73 Impact Factor
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    ABSTRACT: The presence of simultaneous primary tumours in other regions affects the prognosis and management decisions of head and neck cancer patients. Therefore, early detection of these tumours is necessary. Recent improvements in positron emission tomography (PET) have made it possible to examine the patient's whole body. The present study was undertaken to evaluate the clinical contribution of whole-body PET using fluorodeoxyglucose (FDG) for head and neck cancer patients. Fifty-three consecutive patients with previously untreated head and neck cancer were examined. Whole-body FDG PET imaging was performed at 1 h after injection of (18)F-FDG. A 3-D acquisition was undertaken and iterative reconstruction was performed. The final diagnosis of simultaneous primary tumour was established by histological findings or clinical follow-up. Of 53 patients, six (11%) had evidence of simultaneous primary tumour. In five of these six patients, simultaneous primary tumours (two gastric cancer; one colon cancer; one pancreatic cancer; one thyroid cancer) were found by FDG PET. One more patient was found to have prostate cancer on the basis of blood test but this was not detected by FDG PET. In none of the remaining 47 patients, were additional simultaneous primary tumours found by FDG PET or any of the other routine examinations or during follow-up. The results of this study show a high rate of simultaneous primary tumour in patients with primary head and neck cancer. FDG PET appears to be a promising imaging modality for the detection of simultaneous tumours in head and neck cancer patients.
    Nuclear Medicine Communications 04/2005; 26(3):239-44. · 1.38 Impact Factor
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    ABSTRACT: Cartilage invasion in laryngohypopharyngeal cancer has a significant impact on the choice of treatment modality and outcome of the disease. We examined invasion of cartilage in laryngohypopharyngeal cancer by simultaneous bone and tumor dual-isotope SPECT using 99mTc-hydroxymethylene diphosphonate and 201Tl-chloride. Early and delayed simultaneous bone and tumor dual-isotope SPECT were performed on 19 patients with laryngohypopharyngeal cancer. Dual-isotope SPECT images were superimposed to project tumor location from tumor SPECT onto the osseous structures shown by bone SPECT. The presence or absence of cartilage invasion was evaluated histopathologically or by radiological studies such as CT and/or MRI. Histopathological or radiological examination of the cartilage revealed invasion in 5 patients and no invasion in 14 patients. The results of both early and delayed dual-isotope SPECT were exactly the same. Using dual-isotope SPECT, the sensitivity, specificity, and accuracy in detecting cartilage invasion by laryngohypopharyngeal cancer were: 80% (4/5), 92.9% (13/14), and 89.5% (17/19), respectively. Results of the present study suggest that superimposed early bone and tumor dual-isotope SPECT images may be sufficient for the diagnostic evaluation of cartilage invasion by laryngohypopharyngeal cancer. Superimposed dual-isotope SPECT imaging is a useful technique in the evaluation of cartilage invasion in laryngohypopharyngeal cancer.
    Annals of Nuclear Medicine 10/2004; 18(6):527-32. · 1.41 Impact Factor
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    ABSTRACT: We evaluated the usefulness of positron emission tomography with 18F-fluorodeoxyglucose (FDG-PET) in detecting bone metastasis in malignant tumor patients and to compare the results with bone scan findings. Methods: Sixty-five malignant tumor patients who had undergone both FDG-PET and bone scan were selected for this study. The final diagnosis of bone metastasis was established by histological findings or clinical follow-up longer than 3 months involving additional radiographs and/or FDG-PET and/or bone scan findings, showing progressive and extensively widespread bone lesions. Results: Twenty-five patients had one or more sites of bone metastasis. Diagnostic sensitivity, specificity and accuracy were 96%, 97.5% and 96.9%, respectively, for FDG-PET and 80%, 75% and 76.9%, respectively, for bone scan. The one case missed on FDG-PET was of osteoblastic metastasis in breast cancer. On the other hand, bone scan missed five patients of bone marrow metastasis. Conclusions: FDG-PET is more accurate than bone scan in detecting bone metastasis in malignant tumor patients. It is especially superior to bone scan in detecting the bone marrow metastasis.
    International Congress Series 03/2004; 1264:239–242.
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    ABSTRACT: OBJECTIVE: The purpose of this study was to evaluate the usefulness of 201Tl scintigraphy in comparison with three-phase bone scintigraphy in the differentiation of residual/recurrent tumors from post-therapeutic changes, in patients previously treated for bone and soft-tissue tumors. METHODS: Thirty-five 201Tl and three-phase bone scintigraphy scans were obtained for 30 patients with a history of bone or soft-tissue tumor who had undergone chemotherapy, radiation therapy, tumor resection, or a combination of these treatments. The planar 201Tl images were acquired 10 mins (early) and 2 hrs (delayed) after the intravenous injection of 111 MBq 201Tl-chloride. Three-phase bone scintigraphy was performed using 740 MBq 99mTc-HMDP at the same lesion site as for 201Tl imaging. The blood flow images were obtained every 10 sec for 2 mins and were immediately followed by the blood pool image after 5 mins. Three to 4 hrs later, bone images were obtained. 201Tl and three-phase bone scintigraphies were correlated with the histopathologic findings and/or clinical follow-up of more than 3 months. RESULTS: Of the 35 cases, 15 were free of disease and 20 had residual or recurrent tumors. Of the 20 residual or recurrent cases, all had true-positive 201Tl early and delayed scans, while bone scintigraphy was true-positive on the blood flow, blood pool and bone images in 16, 18 and 12 cases, respectively. 201Tl early and delayed images and 99mTc-HMDP blood flow and blood pool images were false-positive in one patient. The histology of this false-positive case showed the presence of lymph proliferative tissue. CONCLUSIONS: Although 201Tl uptake after treatment does not always indicate recurrence, 201Tl scintigraphy may still be more useful than three-phase bone scintigraphy in the follow-up of patients with bone and soft-tissue tumors following therapy.
    Annals of Nuclear Medicine 01/2004; · 1.41 Impact Factor
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    ABSTRACT: Objective: The purpose of this study was to evaluate the usefulness of201T1 scintigraphy in comparison with three-phase bone scintigraphy in the differentiation of residual/recurrent tumors from post-therapeutic changes, in patients previously treated for bone and soft-tissue tumors.Methods: Thirty-five201T1 and three-phase bone scintigraphy scans were obtained for 30 patients with a history of bone or soft-tissue tumor who had undergone chemotherapy, radiation therapy, tumor resection, or a combination of these treatments. The planar201Tl images were acquired 10 mins (early) and 2 hrs (delayed) after the intravenous injection of 111 MBq201Tl-chloride. Three-phase bone scintigraphy was performed using 740 MBq99mTc-HMDP at the same lesion site as for201T1 imaging. The blood flow images were obtained every 10 sec for 2 mins and were immediately followed by the blood pool image after 5 mins. Three to 4 hrs later, bone images were obtained.201Tl and three-phase bone scintigraphies were correlated with the histopathologic findings and/or clinical follow-up of more than 3 months.Results: Of the 35 cases, 15 were free of disease and 20 had residual or recurrent tumors. Of the 20 residual or recurrent cases, all had true-positive201T1 early and delayed scans, while bone scintigraphy was true-positive on the blood flow, blood pool and bone images in 16, 18 and 12 cases, respectively.201T1 early and delayed images and99mTc-HMDP blood flow and blood pool images were false-positive in one patient. The histology of this false-positive case showed the presence of lymph proliferative tissue.Conclusions: Although201Tl uptake after treatment does not always indicate recurrence,201T1 scintigraphy may still be more useful than three-phase bone scintigraphy in the follow-up of patients with bone and soft-tissue tumors following therapy.
    Annals of Nuclear Medicine 01/2004; 18(3):235-241. · 1.41 Impact Factor
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    ABSTRACT: We evaluated the usefulness of positron emission tomography with 18F-fluorodeoxyglucose (FDG-PET) in the detection of gynecological cancer recurrence. Methods: The study evaluated 35 gynecological cancer patients who were suspected of recurrence. FDG-PET imaging was performed at 1 h after 18F-FDG injection. The final diagnosis of recurrence was established by histological findings or clinical follow-up. Results: FDG-PET correctly identified the presence of recurrence in 11 of 12 patients and its absence in 20 of 23 patients. Furthermore, FDG-PET showed new foci that could not be detected by the conventional imaging modalities. These lesions were in supraclavicular lymph node, bone or peritoneum. Furthermore, in two recurrent patients, therapeutic mode was changed from radiotherapy to chemotherapy. Conclusions: FDG-PET imaging is useful to evaluate recurrence of gynecological cancer and to identify more lesions in patients with suspicion of recurrence based on increased tumor marker levels. Furthermore, FDG-PET appears to provide important additional information concerning re-staging, which may help in improving therapeutic strategies in patients with recurrent gynecological cancer.
    International Congress Series 01/2004; 1264:227-232.
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    ABSTRACT: Three-dimensional fast asymmetric spin echo (3D FASE) cisternography provides high spatial resolution and excellent contrast as a water image acquisition technique. It is also useful for the evaluation of various anatomical regions. This study investigated the usefulness and limitations of virtual endoscopic images obtained by 3D FASE MR cisternography in the preoperative evaluation of patients with neurovascular compression. The study included 12 patients with neurovascular compression: 10 with hemifacial spasm and two with trigeminal neuralgia. The diagnosis was surgically confirmed in all patients. The virtual endoscopic images obtained were judged to be of acceptable quality for interpretation in all cases. The areas of compression identified in preoperative diagnosis with virtual endoscopic images showed good agreement with those observed from surgery, except in one case in which the common trunk of the anterior inferior cerebellar artery and posterior inferior cerebellar artery (AICA-PICA) bifurcated near the root exit zone of the facial nerve. The veins are displayed in some cases but not in others. The main advantage of generating virtual endoscopic images is that such images can be used for surgical simulation, allowing the neurosurgeon to perform surgical procedures with greater confidence.
    Magnetic Resonance in Medical Sciences 11/2003; 2(3):145-9. · 0.75 Impact Factor
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    ABSTRACT: A strong association between malignant lymphoma and Hashimoto's thyroiditis has frequently been reported. However, it is difficult to detect the lymphomatous transformation of Hashimoto's thyroiditis in the early stage. The purpose of the present study was to examine the usefulness of 67Ga scintigraphy in the diagnosis and evaluation of the therapeutic effects during follow-up, in patients with a suspected diagnosis of primary thyroid lymphoma. Twenty-five patients who were suspected of having primary thyroid lymphoma and had undergone 67Ga scintigraphy were studied. 67Ga planar scintigraphy was performed 72 hours after injection of 67Ga-citrate. The degree and pattern of 67Ga accumulation were graded visually. Histopathology on biopsy examination revealed thyroid lymphoma in 17 and Hashimoto's thyroiditis in 8 patients. Abnormal accumulation of 67Ga in the thyroid was seen in all of the 17 thyroid lymphoma cases with additional mediastinal and abdominal involvement in one. Fifteen of 17 thyroid lymphoma patients also underwent 67Ga scintigraphy 2-4 weeks after chemotherapy and/or radiotherapy. All 15 patients showed diminishing 67Ga accumulation and a good clinical course. In one patient with local recurrence, abnormal accumulation could be depicted by follow-up scintigraphy. However, diffuse or enlarged accumulation in the thyroid was seen in all of the 8 Hashimoto's thyroiditis cases. The degree of abnormal accumulation in the thyroid in clinically active phase thyroiditis was more intense than that in the chronic phase thyroiditis. 67Ga scintigraphy was helpful to confirm the diagnosis of thyroid lymphoma and to evaluate the therapeutic effects during follow-up. However, 67Ga scintigraphy may not always distinguish thyroid lymphoma from Hashimoto's thyroiditis, especially the active phase of the disease.
    Annals of Nuclear Medicine 08/2003; 17(5):351-7. · 1.41 Impact Factor