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Biomedical subjects

K Hata

Publications and source records attributed to K Hata.

At least 433 records · Page 24Linked to original sources
PubMed1983

Revaluation of treatment result of carcinoma of the hypopharynx using quantification II of multivariate analysis.

In a material of 336 patients with squamous cell carcinoma of the hypopharynx treated from 1956 to 1980, overall 5 year survival rate of carcinoma of the hypopharynx was 25%. According to the stage classification, 5 year survival rates were 74,41,28 and 7% in I,II,III and IV, respectively. As to the treatment modality, 5 year survival rates were 31,24,41,31 and 0% by surgery, radical radiotherapy, preoperative radiotherapy, radical radiotherapy with salvage surgery for recurrence and palliative treatment, respectively. Based on the application of quantification II, we may reasonably conclude that 3 year survivors are mainly discriminated by stage of the disease and treatment modality.

Carcinoma, Squamous Cell↗
PubMed1983

The role of macrophages in preventing metastasis of a homotransplantable hamster lymphoma.

The roles of macrophages in preventing metastasis of a homotransplantable lymphoma were studied in Syrian golden hamsters. Removal of the primary tumor led to enhanced development of metastatic foci. Macrophage activities as demonstrated by macrophage spreading and cytostatic activity were augmented in tumor-bearing hosts, but depressed in tumor-resected hosts. Metastases were facilitated by treatment with silica, an agent that blocks macrophage functions. These results may suggest that immune-activated macrophages contribute to the inhibition of metastases. Metastases were completely inhibited by local irradiation of the primary tumors but such an effect was abolished by the resection of irradiated tumors. Irradiated tumor cells may work as potent immunogens to augment the generation of immune-activated macrophages.

Animals↗
PubMed1982

The weighted geometric center in the remote afterloading intracavitary therapy for carcinoma of the uterine cervix.

In this paper, we investigate the weighted geometric center as one of the parameters to reflect the weight of source arrangement of the intracavitary technique for carcinoma of the uterine cervix. Since the nonrigid applicator is used at our department, there are some differences between point-A doses on both sides, and also between the actual and planned doses of point A, in spite of using our pretreatment computerized dose calculation system. Based on this study, it is suggested that the weighted geometric center is reflected in the inclination of the dose distribution and the ratio of actual to planned mgh which means the weight factor in our pretreatment computerized calculation system. It seems likely that the weighted geometric center is one of the parameters to compare the intracavitary technique for carcinoma of the uterine cervix.

Brachytherapy↗
PubMed1981

A modified dose monitoring system in remote afterloading therapy of carcinoma of the uterine cervix using semi-conductor dosimeter.

A dose monitoring system in high dose rate intracavitary remote afterloading therapy of carcinoma of the uterine cervix using semi-conductor dosimeter was developed in July 1979 at our department. During early experience with the above system, extremely high values of mgh as well as high doses to rectum and bladder were encountered in the cases with poor local anatomy or unsuitable application. Solving this problem, such limitations as to the mgh as well as point-A dose were added to the computerized rapid processing system for the pretreatment dose calculation and correction of the treatment parameters to adjust the point-A dose to within +/- 5% of the planned dose. In the majority of the cases treated with Ralstron, this modified dose monitoring system brought considerable success in the optimization of point-A, mgh, rectal and bladder doses, in a simple manner.

Brachytherapy↗
PubMed1980

A dose monitoring system in high dose rate intracavitary remote afterloading therapy of carcinoma of the uterine cervix using semi-conductor dosimeter.

Our intention was to develop a high accuracy procedure in high dose rate intracavitary remote afterloading therapy of carcinoma of the uterine cervix similar to the accurate dosimetry used in external irradiation. Semi-conductor in-vivo-dosimetry was carried out in order to determine the extent of errors in the calculated dose at reference points and in the definition of point A. The use of a rapid processing computerized system before the treatment was developed in order to decrease the difference between the dose delivered at point A dose and the planned dose. Errors in calculation of within +/- 10% seemed to be unavoidable in the hgh dose rate intracavitary afterloading therapy of carcinoma of the uterine cervix. Two definitions should be used in patients to compute the point A dose according to the ovoid position. Using the rapid processing system, wo could deliver a point A dose within +/- 5% level of the planned dose. The remotely controlled afterloader was safely operated by means of in-vivo-dosimetry which was backed up in routine clinical practice by a pretreatment calculated dose.

Brachytherapy↗