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H Tsujii

Publications and source records attributed to H Tsujii.

At least 91 records · Page 5Linked to original sources
PubMed1990

[Several factors for improving results of radiation therapy].

Various methods have been employed for improving the efficacy of radiation therapy including combined use of radio-sensitizer, chemotherapy, hyperthermia, combination with surgery, intraoperative electron beam therapy, heavy particle therapy, etc. We have evaluated if further improvements in treatment results could be obtained by improving irradiation techniques which are routinely employed in the daily radiation therapy. The results of our evaluation has indicated that therapeutic gains could be raised by: (a) vastly improved radiographic techniques for better visualization of tumor and normal structures, that is, more reliable determination of target volume; (b) improvement of reproducibility of field alignments; (c) improvement of dose distribution by multiportal irradiations.

Humans↗
PubMed1990

[Lipoprotein metabolism analysis in arteriosclerotic diseases].

Lipoprotein metabolism was studied by analyses of apolipoproteins, cholesterol content in lipoproteins and electrophoresis. The findings obtained suggested that the apolipoprotein levels such as A1 and B are related with particle number of lipoproteins such as HDL and LDL, while cholesterol content in lipoproteins is affected by qualitative change in particles as well. In patients with diabetes mellitus (NIDDM), LDL cholesterol correlated with HbA1c, and cholesterol and apolipoprotein B in the beta-area on electrophoresis showed accelerated mobilities, which were mimicked by in vitro glycation of LDL. In coronary heart diseases, elevation of apolipoprotein B and a low level of HDL cholesterol were general findings. The B/A1 ratio could be a sensitive indicator for these diseases. Hyper HDL cholesterolemias, excluding the patients with prostatic cancer who had undergone estrogen-treatment, showed elevated levels of apolipoprotein E in alpha 2-area on electrophoresis. Heterogeneity in Hyper HDL cholesterolemia was implicated. Qualitative analysis of lipoproteins by our method is believed to be useful.

Adult↗
PubMed1989

[Field localization and verification system for proton beam radiotherapy in deep-seated tumors].

It has been recognized that, for precise localization and verification of radiation fields, a marking drawn on the skin surface is not entirely reliable because its position relative to bony structures or internal organs is not stationary. This is especially true when treating deep-seated tumors located below the clavicle. In proton beam radiotherapy at the University of Tsukuba, we ristrict the margins around the target volume. Therefore, special care in field localization and verification is needed, and we make it a rule to take X-ray pictures on each treatment day. To accomplish this, we have developed a localize-and-verify system by using fluoroscopic techniques and combining it with a real-time digital image processing device. This allows for the formation of a digital image of the proton field and storage it in the optic disc. By using this system as well as verification films, filed placement errors were measured in 10 patients with deep-seated tumors. Out of a total of 190 localizations, 22% exhibited a field placement error of more than 5 mm, where patient positioning and field localization were done by using skin drawings aligned with laser beams. This result strongly suggests the necessity for daily localization and verification of radiation fields, as is being done by us, for precision in the execution of proton beam radiation therapy.

Adult↗
PubMed1989

Improved results in the treatment of nasopharyngeal carcinoma using combined radiotherapy and chemotherapy.

A total of 77 patients with nasopharyngeal carcinoma were retrospectively reviewed for the effectiveness of combining chemotherapy (CT) with radical radiotherapy (RT). From 1972 to 1976, 26 patients were treated with a relatively short course of radical RT alone: 52-55 Gy/16 Fx/4 wk (study 1). From 1977 to 1982, 29 patients were also treated with radical RT alone, but with a more prolonged fractionation schedule: 65-70 Gy/26-28 Fx/6.5-7 wk (study 2). In 1983, the policy was to combine CT and RT. From 1983 to 1987, 22 patients received four to six courses of CMU regimen (consisting of cyclophosphamide, methotrexate, and UFT, a 5-fluorouracil analog) after completion of radical RT (study 3). The three studies were comparable with regard to patient characteristics: histologic type, stage, sex, and age distribution. There were no significant differences in survival and relapse figures between study 1 and study 2, but study 3 compared favorably with study 1 and study 2 in actuarial survival, relapse-free survival, relapse rate, and median relapse time. A mild nausea and transient granulocytopenia during CT was the only side effect encountered. In conclusion, the use of CT in combination with RT appeared to increase significantly the chance of long-term survival and probable cure.

Adolescent↗
PubMed1989

The value of treatment planning using CT and an immobilizing shell in radiotherapy for paranasal sinus carcinomas.

This article describes a method which uses CT scans and immobilizing shells radiation treatment planning (CT-assisted planning) for paranasal sinus carcinomas and the value of this method on the treatment outcome. Results of the treatment for 82 patients who had CT-assisted planning were compared with that of 88 patients who had no such treatment planning. It has been concluded that the combined use of CT and the shell in treatment planning permitted a 3-dimensional localization of both the tumor and critical normal structures with great accuracy, leading to an improved long-term survival and a reduced complication rate. The multivariate regression analysis for predicting significant prognostic factors also confirmed the valuable role of CT in terms of survival and primary tumor control. The actuarial 5-year survival rate was 51% in all patients, whereas, by using CT-assisted planning, it was improved to 61%. The improved survival was observed among the patients with tumors of the suprastructures where tumors were located adjacent to the critical organs (brain and eye). Major complications attributable to radiation have included instances of brain and ocular damage. CT-assisted planning, however, has been proven effective in avoiding brain necrosis and preserving eye sight.

Adult↗
PubMed1989

[Radiotherapy of a pure seminoma of the testis].

Twenty-six cases of a pure seminoma of the testis that had been treated by postoperative radiotherapy have been reviewed. The overall 5-year survival rate was found to be 92.3%. Further, no severe adverse effects, including sterility, was found. Prophylactic mediastinal radiation is considered to be unnecessary, because supradiaphragmatic lymph node metastasis was seen in only 1 patient, who has remained disease-free 4.5 year after the treatment of a recurrence. Extranodal metastasis was seen 5 cases, 2 of these cases showing bone metastasis that was successfully treated, thereby achieving complete remission. A seminoma is considered to be one of the most curable malignant diseases, however, long-term follow up is a necessity since stage 1 seminoma has been found to show a generalized dissemination after a 16-year, disease-free interval.

Adult↗
PubMed1988

[The role of radiotherapy in small cell lung cancer].

From 1974 to 1984, we have treated 70 patients with SCLC using radiotherapy (RT) alone or in combination with chemotherapy (CT). It was demonstrated that a heavy CT regimen causing a severe toxicity did not always cause good results. On the other hand, there was a long-term survivor in those patients who were treated with RT alone. Considering from our results as well as from reviews of literatures, it is evident that RT can reduce a significant number of local relapses but has little effect on systemic disease. Therefore, RT added to CT seems to improve a long-term survival specifically in those patients in whom CR is induced from CT. The characteristics of the long-term survivors treated with combined treatment are: limited disease, thoracic RT, good PS, only single site of metastases. In conclusion, there is no doubt that CT plays an important role in the management of SCLC. However, its efficacy is still far from desired, and a new type of CT is warranted.

Carcinoma, Small Cell↗
PubMed1988

[An analysis of needle biopsy under ultrasonography of the thyroid gland].

A multivariate analysis of 47 thyroid nodules and 34 diffuse goiters has been employed to determine the cause of failure in thyroid biopsy under ultrasonography. In the thyroid nodule cases, 30 percent were found to have been misdiagnosed or judged to be an inappropriate sampling. The most important factor leading to failure is a size of tumor. Only one fourth of the small tumors of less than 1 cm were correctly diagnosed and, in cases of a relatively large cystic tumor or a peripherally located nodule, an exact diagnosis was difficult, though 90 percent of the diffuse goiters were difficult, though 90 percent of the diffuse goiters were correctly diagnosed by this method. This result indicates that needle biopsy of the thyroid gland is reliable in cases of a diffuse goiter but problems remain to be resolved in cases of small or cystic tumors and peripherally located nodules.

Adolescent↗
PubMed1987

[Combined chemotherapy and radiotherapy in recurrent tumors of the head and neck region].

Over the past four years, 27 patients with recurrent tumors of the head and neck region have been treated with chemotherapy. The regimens used were BCMF (bleomycin 15 mg i.v. for 3 days, cyclophosphamide 500 mg i.v., methotrexate 50 mg i.v. and 5-fluorouracil 500 mg i.v.) and CMU (cyclophosphamide 350 mg/m2 i.v., methotrexate 30 mg/m2 i.v. and UFT 600 mg p.o. for 14 days). Of the 27 patients, eight were treated with combined radiation and chemotherapy, and either CR or PR was obtained. Nineteen patients were treated with chemotherapy alone, for which the response (CR + PR) rates were 8% (1/12) for BCMF and 43% (3/7) for CMU, respectively. No serious toxicities were observed as a result of these regimens. It was thus demonstrated that the CMU regimen was of great value in terms of improved response and minor toxicity in the treatment of head and neck tumors.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

[Interstitial irradiation by 192Ir seed assemblies in fixed cervical lymph node metastases].

Eleven patients with fixed cervical lymph node metastases were treated using external irradiation followed by interstitial implants, 137Cs needles were used for one patient and 192Ir seed-assemblies for 10 patients. The local tumor responses were 4 CR, 6 PR and 1 NC. Acute tolerance was good, and there were no major late injuries except for one case of severe subcutaneous fibrosis. No morbidities such as local infection, bleeding or pulmonary injuries were encountered. Clear-cut dose control relationships were demonstrated; the local control of the nodes treated with intervals of more than one month between external and interstitial irradiation was poor. It is considered that adequate treatment is to give 40 Gy over 4 weeks by external irradiation first, then, after an interval of 2 weeks, to give 40-50 Gy over 4-5 days using 192Ir interstitial implants. The interstitial implants appeared to provide an improvement in local control and in the therapeutic ratio of fixed cervical lymph node metastases.

Aged↗
PubMed1987

[Contribution of CT and MRI to radiation therapy].

The contribution of CT to radiation therapy has been enormous. The most basic contribution has been that CT has made almost all malignant tumors visible, which has improved radiation therapy not only in the planning phase but also in the effect-estimating phase. As some examples, CT has improved the effects of radiation therapy for cancer of the maxillary sinus and of the uterine cervix, and the results from our department have already been published. The contribution of MRI to radiation therapy should be very great in future wherever MRI diagnostics are established. Even now, however, its ability to visualize cross-sectional anatomy in any area is an aid to radiation therapy both in planning and in estimating the degree of effect.

Brachytherapy↗
PubMed1987

[The optimized dosage specific for different organs with regard to late effect].

Clinical and experimental evidence indicates that the optimized dosage may be different from organ to organ. In an effort to find an optimized dosage for laryngeal cancer treated in our department, the NSD-TDF concept and linear-quadratic (LQ) model were employed. The dose-fractionations using 2.5 Gy per fraction gave better results in terms of local control and complications than those using bigger fraction size and shorter treatment period. It is generally agreed that the maxillary cancer is best managed by combined radiation and surgery with or without chemotherapy. When irradiation is given in 16 fractions over 4 weeks, the local control and survival were decreased with increasing total dose, suggesting the presence of the supra-lethal dose phenomenon which was first mentioned by the Manchester group. The optimized dosage for carcinoma of the uterine cervix is more complicated, because both the external irradiation and intracavitary irradiation are combined for this disease. Our clinical data indicated that the optimal fractionation is: 50 Gy of total pelvic irradiation with the last 10-15 Gy given using a central shielding followed by RALS treatment delivering 30 Gy in 6 fractions at point A.

Humans↗