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Featured researches published by Takeo Okuyama.


International Journal of Radiation Oncology Biology Physics | 1982

Results of brachytherapy for cancer of the tongue with special emphasis on local prognosis

Junichi Horiuchi; Takeo Okuyama; Hitoshi Shibuya; Masamune Takeda

One hundred and sixty-six patients with squamous cell carcinoma of the tongue were treated with radiation. Treatment modalities were mainly interstitial implant with or without external beam irradiation, except for early lesions, which were treated with intraoral electron beam therapy. Analysis was made on the local prognosis of the lesion to clarify the indications for interstitial therapy, especially the combined program with external beam therapy, and the time-dose relationship of the brachytherapy. Local recurrence-free rates (two years) were 94% in T1, 77% in T2 and 32% in T3 lesions, respectively. For T1 and superficial or exophytic T2 lesions, the local recurrence-free rate was excellent with the interstitial therapy alone using either permanent implants of gold grain or radium implants. Therefore, prior external beam therapy seemed to be unnecessary for these lesions. When the treated area was less than 10 cm2, subsequent complications were not likely even if the TDF (time-dose factor) value was high. Most of the patients who received combined external beam and interstitial therapy showed infiltrative T2 and a majority of the T3 lesions. In these patients, it was apparent that most of the total dose should be given from the interstitial implant after a small prior dose with external irradiation, because these lesions could not be cured even if the external dose was increased.


Cancer | 1982

Reappraisal of trimodal combination therapy for maxillary sinus carcinoma

Hitoshi Shibuya; Soji Suzuki; Junichi Horiuchi; Minoru Takagi; Takeo Okuyama; Hitoshi Suzuki; Masamune Takeda

The introduction of trimodal combination therapy (surgery + radiation + intraarterial infusion) for maxillary carcinoma resulted in a change in the sites of recurrence and no satisfactory improvement in the local control rate. To examine the cause of these phenomena, external carotid angiography was performed on 51 patients prior to the start of the therapy and the results of the treatment were studied. Angiographic findings indicated that maxillary carcinoma is fed not only by the maxillary artery, but also by the internal carotid, facial, transvers facial and other arteries from the external carotid artery. The multiplicity of feeders causes irregular distribution of the intraarterially infused antimetabolites. Irregular and local low distribution of antimetabolites may well bring about the high rate of recurrence. The results of intraarterial transcatheter Tc‐99m‐MAA injection were also in accord with the angiographic findings.


Acta Oncologica | 1982

Extranodal Non-Hodgkin's Lymphoma in the Head and Neck: Irradiation and clinical course

Junichi Horiuchi; Takeo Okuyama; Sho Matsubara; Hitoshi Shibuya; S. Suzuki; Ryuichi Kamiyama

A retrospective analysis was performed of localized extranodal non-Hodgkins lymphomas in the head and neck region treated with irradiation. Histopathologic reevaluation revealed 94 per cent with a diffuse type. The lesions were as a rule locally cured with doses ranging from 30 to 50 Gy. Relapses in localized stage I and II patients were, however, not seldom observed in distant extranodal sites. Gastrointestinal relapse in cases with lesions originally located in Waldeyers ring was thus frequently observed, and the probability of multiple or systemic involvement should be considered also when the disease is located in the oral cavity or sinus region. The value of systemic examination for staging purposes is discussed.


Clinical Nuclear Medicine | 1985

Diagnosis of aneurysmal bone cyst of the mandible. A report of two cases with emphasis on scintigraphic approaches.

Takeo Okuyama; Hitoshi Suzuki; Isao Umehara; Yuji Kuwabara; Soji Suzuki; Minoru Takagi

Aneurysmal bone cyst is rarely found in the mandible, and roentgenographic diagnosis of this condition is not easily made. In this report, the diagnostic value of bone scintigraphy and radionuclide angiography and CT imaging in two cases of aneurysmal bone cyst of the mandible are discussed. Bone scintigraphy with Tc-99m MDP demonstrated ring-like or doughnut-pattern accumulation of radioactivity, which corresponded to the expansile character of the bony lesion. The accumulation of radioactivity was intensive in the peripheral region despite the fact that the lesion was benign. Furthermore, the central rarefaction showed that the lesion was cystic. Radionuclide angiography with Tc-99m HSA, including blood pool scan, did not detect radioactive concentration. Thus bone scintigraphy and radionuclide angiography were found to be essential in the differential diagnosis of aneurysmal bone cyst from other forms of tumor, especially hypervascularized tumor and central hemangioma of the mandible.


Clinical Radiology | 1982

The radiological appearances of familial metaphyseal dysplasia

Hitoshi Shibuya; Soji Suzuki; Takeo Okuyama; Yoshinobu Yukawa

Familial metaphyseal dysplasia (FMD) is a rare genetical conditional characterised by symmetrical metaphyseal splaying of the tubular bones. The diagnosis of FMD was made in four patients from two families in Japan; abnormal modelling defects were observed in the flat bones as well as tubular bones in some of the patients. In addition, quantitative measurement of the mineral content of the bone was carried out and was found to be one-quarter of the normal value.


International Journal of Radiation Oncology Biology Physics | 1985

Chromosome aberrations in the peripheral lymphocytes induced by brachytherapy and external cobalt teletherapy

Sho Matsubara; Junichi Horiuchi; Takeo Okuyama; D.D.S. Masamune Takeda; Hitoshi Shibuya; S. Suzuki; Kunikazu Kishi

In the present study, the induction efficiencies of chromosome aberrations were analyzed in patients receiving various modalities of interstitial radiotherapy with small radiation sources in the oral cavity area and compared with those in patients treated with external telecobalt irradiation in the thoracic region. Further, as a local nonstochastic effect, the acute mucosal reaction was investigated. The mucosal reaction in the area treated by brachytherapy reached a maximum at two to three weeks after the implantation. The frequencies of dicentrics plus rings of peripheral lymphocytes, on the other hand, revealed rapid increases and approached plateau levels as early as two days after the implantation. The whole-body effects, evaluated on the basis of the chromosome aberration frequencies of peripheral lymphocytes in the patients who underwent brachytherapy, were compared with the effects observed in those patients treated with external radiotherapy or bleomycin injection and discussed with regard to their effectiveness in control of the tumor and side effects. The radiation doses used in the patients who received brachytherapy or a single external irradiation were found to exert the same effects on the chromosome aberration induction. However, even in the case of brachytherapy in which whole-body side effects were believed to be trivial, the peripheral lymphocyte count was temporarily reduced to one half or less of the preirradiation level. An equivalent whole-body dose of 50 cGy was obtained from the frequencies of dicentrics and rings.


Cancer | 1986

Radionuclide lymphoscintigraphy performed on the mastectomized chest wall

Sho Matsubara; Isao Umehara; Hitoshi Shibuya; Takeo Okuyama; Junichi Horiuchi; Soji Suzuki; Hitoshi Suzuki; Masakazu Ebuchi


Japanese Journal of Oral and Maxillofacial Surgery | 1982

Diagnosis of cervical lymph node metastasis from oral carcinoma by CT scan

Tadao Tachibana; Teruo Amagasa; Hiroshi Iwaki; Emiko Yokoo; Kazuko Sato; Shigetoshi Shioda; Yuji Kuwabara; Takeo Okuyama


Japanese Journal of Oral & Maxillofacial Surgery | 1973

Eosinophilic granuloma of soft tissue in the cheek and submandibular region: Report of 3 cases

Katsuhiko Aiko; Ken-ichi Michi; Sadao Okohira; Masatsugu Shimizu; Tadashi Ueno; Akira Komori; Junichi Horiuchi; Takeo Okuyama


Japanese Journal of Oral & Maxillofacial Surgery | 1972

Clinical observations on osteoradionecrosis of the mandibles

Akio Mizuno; Katsunori Ishibashi; Masatsugu Shimizu; Tadashi Ueno; Takeo Okuyama

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Junichi Horiuchi

Tokyo Medical and Dental University

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Hitoshi Shibuya

Tokyo Medical and Dental University

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Sho Matsubara

Yokohama City University

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Soji Suzuki

Tokyo Medical and Dental University

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Hitoshi Suzuki

Tokyo Medical and Dental University

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Masamune Takeda

Tokyo Medical and Dental University

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Akio Mizuno

Tokyo Medical and Dental University

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Isao Okayasu

Tokyo Medical and Dental University

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Isao Umehara

Tokyo Medical and Dental University

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Masatsugu Shimizu

Tokyo Medical and Dental University

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