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Biomedical subjects

H Shirato

Publications and source records attributed to H Shirato.

114 records · Page 7Linked to original sources
PubMedDate not supplied

Detection of pion-induced radioactivity by autoradiography and positron emission tomography.

An autoradiographic technique incorporating a new imaging system was used to detect pion-induced radioactivity in Plexiglass and the results were compared with aluminium activation and PET imaging. The activity distribution in the region of the pion-stopping peak was similar in all three cases. Another large signal in the entrance region due to in-flight interactions [12C(pi-, pi- n) 11C] was detected by autoradiography and by PET but was not reflected in the aluminium activation measurements. This new technique is capable of defining the stopping region in phantoms with a better resolution than PET scanning and is useful as a complementary technique to other methods of pion dosimetry.

Autoradiography↗
PubMedDate not supplied

Results of prophylactic adjuvant chemotherapy for early stage non-Hodgkin's lymphoma of the head and neck.

Results were reviewed in 46 patients who had stage I and II head and neck non-Hodgkin's lymphoma, and received five to six cycles of CVP chemotherapy after regional irradiation. Disease-free survival, pattern of relapse, and time of relapse were compared with those of 64 patients, who received regional irradiation alone. Adjuvant, post irradiation CVP significantly improved five-year survival in stage I (and IE) disease, 49.6% to 81.9% (p less than 0.05), but was less successful in patients with heavier tumor burden, such as stage II disease or advanced loco regional disease in Waldeyer's ring (48.3% to 63.7%; p greater than 0.10 in stage II patients). In addition, in those who relapsed, the time and pattern of relapse were not altered by adjuvant CVP chemotherapy. This easily tolerated, mild adjuvant chemotherapy, we conclude, failed to prove significant in preventing relapse, especially in patients with heavier tumor burden.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

Long-term results of treatment with mild toxicities in small cell lung carcinoma.

Results of treating small cell lung carcinoma with mild toxicities were investigated retrospectively. From 1974 to 1981, 38 patients were treated according to three institutional protocols: radiation alone (RAD), radiation with ifosfamide (IFOS), and radiation with adriamycin, vincristine, and cyclophosphamide (AOC). Of the three five-year survivors, two were treated with IFOS and one with RAD. The time period between admission and the beginning of radiotherapy was longer and the treatment field smaller in AOC than in the other two protocols. IFOS and RAD showed less toxicity. Our study indicated that IFOS and RAD should be regarded as curative treatments for limited disease and are suitable for patients who do not have sufficient bone marrow reserve.

Adult↗
PubMedDate not supplied

Ultrasonographic measurement of tumor regression in radiation therapy.

Ultrasonography was evaluated as a measurement procedure for investigating the tumor regression of cervical lymph nodes. Preliminary results suggested that interobserver compatibility in the measurement of nodes deteriorates when the diameter of the node is less than 15 mm. There was no systematic disparity between ultrasonographic and manual measurements. The tumor regression line fit the exponential line with a correlation coefficient of more than 0.95 in seven of 16 nodes. During the sequential examination, a central low-echo area suddenly appeared in one node at 15 Gy/6 Fr.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

CT-aided volumetry and prognosis in cervical carcinoma.

Since January 1981, 128 CT evaluations were systematically applied to 85 patients of histologically proven squamous cell carcinoma of the cervix uteri before and after external irradiation (i.e., at the beginning of intracavitary therapy). CT-measured cervical mass volume and mass-pelvic wall distance were analyzed in relation to prognosis, namely, local control at one year after irradiation and three-year survival. Regardless of clinical stage, CT-measured volume and mass-pelvic wall distance were revealed to be closely related to prognosis. In 46 patients whose cervical mass volume regressed to less than 48 cm3 after external irradiation, 44 (95.6%) were locally controlled for more than a year, and the three-year actuarial survival of this group was 71.6 + 6.2%. On the contrary, in those whose volume was over 48 cm3 at the end of external irradiation, only 3 out of 18 were locally controlled, and the three-year survival was 7.4 + 6.0. Mass-pelvic wall distance was also related to tumor control. CT was found to provide fairly objective, reproducible information for detecting the high-risk subgroup in cervical carcinoma under uniform treatment conditions.

Brachytherapy↗