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Biomedical subjects

H Fukuda

Publications and source records attributed to H Fukuda.

1,384 records · Page 77Linked to original sources
PubMedDate not supplied

Radiation therapy for metastatic spinal tumors.

PURPOSE: The results of radiation therapy for metastatic spinal tumors were evaluated in terms of pain relief, improvement of neurological impairment, and survival. MATERIALS AND METHODS: Between 1986 and 1995, 52 symptomatic patients with metastatic spinal tumors treated with radiation therapy were evaluated. The patients all received irradiation of megavoltage energy. Therapeutic efficacy was evaluated in terms of pain relief and improvement of neurological impairment. RESULTS: Pain relief was observed in 29 (61.7%) of 47 patients with pain. Therapy was effective for 17 (70.8%) of 24 patients without neurological impairment, and efficacy was detected in 12 (52.2%) of 23 patients with neurological impairment. Improvement of neurological symptoms was obtained in seven (25.0%) of 28 patients with neurological impairment. CONCLUSION: Radiation therapy was effective for pain relief in patients with metastatic spinal tumors. In patients with neurological impairment, less pain relief was observed than in those without impairment. Improvement of neurological impairment was restricted, but radiation therapy was thought to be effective in some cases in the early stage of neurological deterioration. Radiation therapy for metastatic spinal tumors contraindicated for surgery was considered effective for improvement of patients' activities of daily living.

Activities of Daily Living↗
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Radiation pneumonitis following multi-field radiation therapy.

The mechanisms of radiation pneumonitis have not been established. In a study on multi-field radiation therapy for lung cancer, one patient developed severe radiation pneumonitis even though the target volume was small. Radiation therapy was performed at a dose of 75 Gy in 50 fractions over five weeks. High-density areas conforming to the radiation field were observed by high-resolution CT. They were observed in the irradiated volume at doses under 20 Gy in the contralateral lung as well as in the ipsilateral lung.

Aged↗
PubMedDate not supplied

Development of a new heating needle for interstitial hyperthermia compatible with interstitial radiotherapy.

PURPOSE: We have developed a new heating needle for interstitial hyperthermia compatible with brachytherapy. We studied the heating characteristics of interstitial needles and the usefulness of these needles for interstitial hyperthermia. MATERIALS AND METHODS: As heating needles, we used MicroSelectron HDR interstitial needles. These needles were only heated at the metal tip, and were insulated in the middle and grounded from the top. The hyperthermia system was based on the principles of RF capacitive heating, and we used a Thermotron RF-8. We examined whether the temperature and the heating area could be elevated to a level required for hyperthermia. RESULT: Good heating was obtained around the metal tip of the needle. The heating area of the longitudinal axis of the needle varied with the length of the metal part, while the transverse heating area of the needle was almost unchanged. If heating was performed while maintaining the elevation of temperature in each needle at the same level using variable coils (tuning box), heating was homogeneous over the regions in accordance with the arrangement of the needles. CONCLUSION: With this heating system, the temperature rises easily, and a uniform temperature distribution can be obtained.

Brachytherapy↗
PubMedDate not supplied

Intraluminal irradiation for T2M0 esophageal cancer: effect of patient selection on prognosis.

The contribution of intraluminal irradiation to the prognosis of T2M0 esophageal cancer was examined with reference to patient selection. To determine the effect of patient selection, we used esophagrams to assess the potential difficulty of inserting a tube for intraluminal irradiation in 39 patients who were treated with external irradiation prior to 1982. Twenty-two patients were assessed as likely to have been able to undergo intraluminal irradiation (group 1) while 17 were assessed as unlikely to have been able to undergo the procedure (group 2). Of 36 patients treated after 1983, 19 patients were treated with a combination of intraluminal irradiation and external beam therapy (group 3) and 17 by external irradiation alone (group 4). The median survival times of groups 1, 2, 3, and 4 were 10.8, 6.4, 12.0, and 8.5 months, respectively. The prognosis of patients treated with combination therapy (group 3) was superior to that of those treated before 1982 (groups 1 + 2). However, there was no improvement in the prognosis of T2M0 esophageal cancer treated by radiotherapy after the introduction of intraluminal irradiation, and the difference between the survival curves of patients treated by combination therapy (group 3) and with a wide esophageal lumen (group 1) was not significant. Our study thus showed that the selection of patients according to the insertability of the intraluminal therapy tube affected the prognosis.

Aged↗
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Measurements of the effect of dipyridamole on regional myocardial blood flow with positron emission tomography and the first-pass flow model.

We assessed percent changes of regional myocardial blood flow (RMBF) after infusion of dipyridamole (0.56 mg/kg) with dynamic N-13 ammonia PET and the first-pass flow model. Positron emission tomography (PET) was performed at rest and after infusion of dipyridamole in 17 participants [five normal subjects, five patients with hypertrophic cardiomyopathy (HCM), and seven patients with coronary artery disease]. Dipyridamole increased RMBF 126 +/- 69% (mean +/- SD) in normal subjects and 55 +/- 43% in the patients with HCM. In the cases of coronary artery disease, the percent changes of RMBF were +19 +/- 19% in ischemic areas and +76 +/- 23% in nonischemic areas. These results demonstrate that N-13 ammonia dynamic PET study is useful in assessing the percent changes of RMBF induced by dipyridamole infusion.

Adult↗
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Potential usefulness of an artificial neural network for assessing ventricular size.

An artificial neural network approach was applied to assess ventricular size from computed tomograms. Three layer, feed-forward neural networks with a back propagation algorithm were designed to distinguish between three degrees of enlargement of the ventricles on the basis of patient's age and six items of computed tomographic information. Data for training and testing the neural network were created with computed tomograms of the brains selected at random from daily examinations. Four radiologists decided by mutual consent subjectively based on their experience whether the ventricles were within normal limits, slightly enlarged, or enlarged for the patient's age. The data for training was obtained from 38 patients. The data for testing was obtained from 47 other patients. The performance of the neural network trained using the data for training was evaluated by the rate of correct answers to the data for testing. The valid solution ratio to response of the test data obtained from the trained neural networks was more than 90% for all conditions in this study. The solutions were completely valid in the neural networks with two or three units at the hidden layer with 2,200 learning iterations, and with two units at the hidden layer with 11,000 learning iterations. The squared error decreased remarkably in the range from 0 to 500 learning iterations, and was close to constant over two thousand learning iterations. The neural network with a hidden layer having two or three units showed high decision performance. The preliminary results strongly suggest that the neural network approach has potential utility in computer-aided estimation of enlargement of the ventricles.

Cerebral Ventricles↗
PubMedDate not supplied

Lymphangioma of the mesentery and small intestine: a case report showing a solid tumor with a cystic component on US and CT.

We encountered a patient with multiple lymphangiomas of the mesentery and small intestine. Ultrasonography and computed tomography showed a mesenteric tumor composed of a solid component with a small cystic part. This unusual appearance made the differential diagnosis between lymphangioma and other intra-abdominal solid tumors difficult.

Diagnosis, Differential↗
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Human melanoma treated by boron neutron capture therapy: comparison of the clinical response with the predicted response.

PURPOSE: A patient with malignant melanoma on the left foot was treated by thermal neutron capture therapy using 10B-paraboronophenylalanine. We compared the actual (clinical) response with the predicted response estimated using our past experimental and clinical data, and discussed some problems to be overcome in the future. MATERIALS AND METHODS: We adopted an intravenous drip infusion of the compound whereby 170 mg/kg of the drug was administered over 4-5 hours before neutron irradiation. The patient was then irradiated with thermal neutrons from the Musashi Reactor at a reactor power of 100 kW and a neutron flux of 1.0 x 10(9) n/cm2/s at the collimator surface. The total absorbed dose to the melanoma and the surrounding skin was calculated by multiplying the thermal neutron fluences by the conversion factor. RESULTS: The total absorbed doses to the melanoma and the surrounding normal skin were calculated as 19.0 and 9.4 Gy, respectively. These absorbed doses were estimated at 33.5 and 14.2 RBE-Gy, respectively, assuming that the relative biological effectiveness (RBE) of the high LET radiations was 2.0 and that each component of the mixed radiation was simply additive. The melanoma showed marked regression with mild skin reaction (dry desquamation) a month after therapy, and finally disappeared 10 months after therapy. There were no no substantial side effects. CONCLUSION: We concluded that the outcome of our calculated dose values agreed well with the clinical response and that their compatibility indicated considerable validity for our approach. However, there are still some problems-uncertainty concerning the 10B concentration in tumor and skin, determination of the total absorbed dose, and a single curative dose for malignant melanoma-to be overcome with regard to clinical use of this therapy.

Aged↗
PubMedDate not supplied

A case of malignant schwannoma with overexpression of multidrug resistance gene (MDR1) after chemotherapy.

A 19-year-old:female patient with malignant schwannoma in the right knee was treated by combination chemotherapy including lipophilic anticancer compounds (cyclophosphamide, doxorubicin, vincristine and dacarbazine). The tumor was radically removed after chemotherapy, but metastatic lesions were noted in the right inguinal nodes. The patient died due to the cachexic state six months after surgery. In human neoplasm, P-glycoprotein (P-Gp) encoded by human multidrug resistance gene MDR1 is known to be related with multidrug resistant phenotype. Northern blot analysis revealed apparent MDR1 expression in the metastatic lesion, while the primary lesion showed faint MDR1 expression detected by only reverse transcriptase-polymerase chain reaction. P-Gp positive tumor cells were immunohistochemically detected both in the metastatic lesion and the primary lesion. The P-Gp-positive tumor cells in the metastatic lesion showed anaplastic features with highly atypical nuclei. These results suggest that MDR1 overexpression is related to the multidrug resistance phenomenon in the malignant schwannoma with morphological differences.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMedDate not supplied

Immunohistochemical demonstration of alpha-fetoprotein in small hepatocellular carcinoma.

We demonstrated immunohistochemical staining of a-fetoprotein (AFP) in small hepatocellular carcinoma (HCC). Fifty-six patients with HCC less than 2 cm in diameter were studied. Twenty-five HCCs (44.6%) were positive for AFP-staining. The positive rate of AFP-staining in HCC tissue was higher in the patients with serum AFP concentration above 20 ng/ml than that of the patients with below 20 ng/ml. AFP-staining was demonstrated on the rough endoplasmic reticulum of HCC cells by immuno-electron microscopy. AFP-staining of tissue specimens obtained by fine needle biopsy is useful in the histologic diagnosis of HCC.

Aged↗