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Biomedical subjects

Y Kyuma

Publications and source records attributed to Y Kyuma.

8 recordsLinked to original sources

Stereotactic radiosurgery using a linear accelerator.

A basic and clinical study of radiosurgery using the linear accelerator (Linac) system for unremovable deep-seated brain tumors is reported. A Komai stereotactic ring was used to locate the target coordinates. The patient was laid on the Linac treatment table and held in the head fixation system. Irradiation was given in five positions. The dose profile by film dosimetry and Rando phantom was satisfactory. Seventeen tumors in 14 patients were treated. Clinical or histological diagnoses were nine metastases, one benign and two malignant gliomas, one meningioma, and one craniopharyngioma. Tumor sizes were between 8 and 30 mm. Doses were between 12 and 30 Gy. Computed tomographic evaluation after 3 months of 12 tumors in 11 survivors showed one complete remission, three partial remission, six no change, and two partial deterioration. For progressive tumors, Linac radiosurgery results are excellent.

Adult

Subarachnoid dissemination of pineal germinoma 9 years after radiation therapy without local relapse--case report.

A 22-year-old female developed intracranial and spinal subarachnoid metastases 9 years after radiation therapy for a pineal germinoma. Computed tomographic scans showed no evidence of local recurrence. Cerebrospinal axis irradiation achieved total remission. Delayed subarachnoid dissemination may be caused by germinoma cells remaining dormant in the subarachnoid space, outside the radiation field.

Brain Neoplasms

[Intra-arterial infusion of high dose methotrexate therapy in recurrent gliomas].

Intra-arterial high dose methotrexate (MTX) infusion therapy for ACNU resistant recurrent gliomas was reported. MTX was administered 16 times to 6 patients. In all cases, 20% mannitol was infused to produce a reversible osmotic blood brain barrier disruption. Dosage of infused MTX was 1,000-2,000 mg per an artery. One case revealed a complete response on CT. Another case showed an intratumoral necrosis. Intra-arterial high dose MTX infusion yielded high arterial and cerebrospinal fluid concentration of MTX. No critical complications were experienced. Dosage of MTX, an interval between the therapies and proper timing to start leucovorin rescue will be discussed.

Adult

[Management results of primary intracranial malignant lymphoma].

Nineteen cases of primary malignant lymphoma of the central nervous system were reported. The clinical characteristics, diagnostic procedure and therapeutic method, especially concerning chemotherapy, were analysed. The following conclusions were obtained: 1) histological classifications and surgical procedures were not factors involved in prognosis. 2) radiotherapy was regarded as an effective but a palliative treatment. 3) combined chemotherapy for systemic malignant lymphoma, such as VEMP, VEP, COPP, seemed to be of little use for intracranial malignant lymphoma. 4) intra-arterial administration of high-dose methotrexate, ACNU and intravenous administration of high-dose cytosine arabinoside can be expected to be a useful chemotherapeutic approach.

Adolescent