Biomedical subjects
Publications and source records attributed to H Uozumi.
A seven-year-old case with chronic dacryocystitis resulting from congenital obstruction of the nasolacrimal duct was cured not by a dacryocystorhinostomy but by probing of the duct. Our results show that even in case of planned dacryocystorhinostomy, probing of the duct should be performed at least once.
Primary malignant lymphoma of the brain (PMLB) is uncommon. Between 1975 and 1982, the authors observed 11 patients with histologically confirmed PMLB. Mean survival after radiation therapy was 7 months with 5 patients surviving for more than 2 years. Multifocal lesions were seen in 9 patients and spontaneous regression was seen at computed tomography in 2 patients. Radiation doses in excess of 30 Gy controlled the primary tumor, but intracranial recurrences occurred even after whole brain irradiation to 40 Gy. Only one patient had a relapse outside the central nervous system, and none had clinical evidence of seeding to the spinal canal. The authors postulate that PMLB usually is a multifocal intracranial disease, and that whole brain irradiation of at least 30 to 40 Gy should be given to all patients with this disease.
One hundred and four patients treated with radiotherapy for intracranial tumors and their related conditions were reviewed to evaluate the usefulness of magnetic resonance (MR) imaging in demonstrating increased signal intensity areas on T2-weighted images that were considered to be late adverse effects of irradiation of the brain. High signal intensity areas of the white matter were divided into five patterns according to their size and extension. Severity was found to increase with age and irradiation doses of more than 50 Gy. In patients with irradiation doses of more than 60 Gy, the severity of increased with shorter interval after radiotherapy than in those given low irradiation doses. Clinical findings such as mental deterioration, motor abnormality, and visual defect were observed in 12 patients. These findings were closely correlated with the severity of the MR pattern. In most patients, high signal intensity areas were stable or progressive during the course of follow-up. However, these areas were regressive in three patients. Imaging with Gd-DTPA was performed in 36 patients, six of whom showed enhancement. Pathological findings on enhancement included astrocyte proliferation and coalescing vacuoles in neural tissue. MR imaging is an excellent method with which to monitor the adverse effects of radiotherapy of the brain.
MR examinations of 104 patients who had undergone radiotherapy to the brain were reviewed. Thirty-six patients received Gd-DTPA enhanced study during the course of MR evaluation and six of the patients showed enhancing radiation necrosis. Histopathological confirmations were obtained in three patients. Gd-DTPA enhancing radiation lesions were multiple and patchy in three patients, multiple and patchy with cyst formation in two and ring shaped in one. In terms of their distribution, enhancing lesions in four patients were seen only in the white matter within the irradiated field and these patients had undergone radiotherapy within five years. The interval after radiotherapy was more than eight years in two patients and their enhanced lesions were observed in both the white and gray matter. Histopathological findings of Gd-DTPA enhancing radiation necrosis were gliosis and coalescing vacuoles of the neural tissue. None of these enhanced radiation lesions showed significant mass effects. Patterns of the enhancement were not specific. It was considered to be difficult to differentiate tumor recurrence from radiation necrosis with conventional Gd-DTPA enhanced MR examinations. In one patient, delayed MR images after Gd-DTPA administration showed increases in the size and number of radiation enhanced lesions. Dynamic and delayed MR study might add more information to conventional imaging after Gd-DTPA. Further studies are necessary to differentiate radiation lesions from tumor recurrences.
Five patients with adult T-cell leukemia (ATL) were treated by irradiation. Of the five patients, four were irradiated only locally to enlarged lymph nodes or cutaneous lesions as a palliative therapy. The other patient was given a single dose of 10 Gy to the total body as a definitive treatment, followed by autologous bone marrow transplantation. All five patients were treated by combined chemotherapy before irradiation. Complete reduction of lymph node enlargement and cutaneous lesions was achieved with a dose of 20 to 30 Gy. Four patients died within three months after radiotherapy, but there was no recurrence in the radiation field while new lesions developed. One patient in whom cutaneous lesions developed again after nine months of remission was alive at 10 months after irradiation. These patients responded poorly to chemotherapy. Local lesions produced by ATL were sensitive to irradiation and could be controlled by moderate irradiation doses without severe side effects. Radiotherapy did not prolong survivals, but it should be considered as a palliative method in multimodal treatment for ATL.
Radiation and thermal characteristics of L5178Y cells and their radiation-sensitive mutant M10 cells were studied by the colony-forming method and the dye-exclusion method using eosin-Y. Although M10 cells were remarkably radiation-sensitive compared with L5178Y cells, it was difficult to cause interphase death of M10 after a large dose of irradiation. After heat treatments, L5178Y cells revealed more cell destruction and were stained well by eosin-Y, but it was relatively difficult to produce cell destruction of M10 cells, which showed poor staining by eosin-Y. When assayed by the colony-forming method, M10 cells were also heat-resistant compared to L5178Y. The dye-exclusion rate was closely correlated with cell survival after hyperthermia of L5178Y cells, suggesting that this is a simple method of detecting the thermosensitivity and thermotolerance of cancer cells. The difference in survival of L5178Y cells and M10 cells after combined treatment with gamma irradiation and hyperthermia was smaller than with gamma irradiation alone. It was also found that there was a relationship between radiation-induced interphase death and hyperthermia-induced interphase death, and that interphase death accounted for a major part of cell death caused by hyperthermia in mouse leukemia cells.
In order to achieve better thermal distribution, a high output radiofrequency capacitive heating system was developed for hyperthermia and operated at a frequency of 13.56 MHz with an output of 1,000 watts (Inter Nova Inc., IH-1000). With use of this equipment, an agar phantom study, an animal experiment, and a clinical trial have been performed. This unit has made it possible to use large applicators with large electrodes. The phantom study revealed homogeneous, deep-heating capability. In the animal study using a miniature pig, good thermal distribution within the body was obtained, but the problem of overheating the subcutaneous fat layer remained. In the clinical application, some limiting factors remained unsolved in spite of our attempts to eliminate them; however, the problem of insufficient power supply was solved.
From January 1985 to October 1986, 25 tumors in 23 patients were treated with combined hyperthermia and radiation therapy. All of these tumors were recurrent tumors after initial radiation therapy, and were presumed to be radioresistant tumors on the basis of histological findings and poor response at 30-40 Gy. Heat was delivered using the radiofrequency of 13.56 MHz at 500 W or 1000 W. In combination with radiation therapy, hyperthermia was given at 42 degrees-43 degrees C for 30 minutes per fraction once a week for a total of four to five fractions (Protocol 1), or twice a week for a total of six to 10 fractions (Protocol 2). Hyperthermia once a week was as effective as twice a week. Small and diffuse tumors showed better results. Combined therapy was better than irradiation alone for suppression of these tumors. The adverse effects included three subcutaneous fat necroses with an associated lipoma in one case and three skin ulcers.
A retrospective analysis was performed to investigate the radioprotective effects of azelastine against radiation dermatitis for patients with head and neck cancers. The effects of azelastine were studied in 19 patients with laryngeal cancers treated by irradiation. As controls, 29 patients with laryngeal cancers treated by irradiation without the administration of azelastine were studied. All patients were irradiated using 3 MV linac X-rays. Azelastine was administered orally twice a day. Moist desquamation was observed in four of 29 control patients whereas no such moist desquamation developed after the administration of azelastine. Two cases of moist desquamation that developed before the administration of azelastine regressed during irradiation in patients placed on azelastine. Radiotherapy was completed without interruption in all patients treated with azelastine. No severe side effects were observed. Azelastine, administered orally, was a safe drug and has the potential of improving skin tolerance in irradiation therapy.