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Biomedical subjects

J Honjo

Publications and source records attributed to J Honjo.

7 recordsLinked to original sources

[Experimental studies on the combined effect of radiation and UFT: 2. fractionated treatments combining UFT and X ray radiation].

The combined effects of fractionated radiation and UFT, which is a mixture of tegafur (FT) and uracil, have been studied using C3H mouse mammary carcinoma. The tumor was implanted in the right hind legs of and irradiated with 300R daily for either 10 or 15 days. UFT (FT 15mg/kg + uracil 33.6mg/kg) was intra-gastrically administered 2 hr. before irradiation. Dose modifying factor (DMF) of UFT obtained from the tumor growth delay assay was 1.52 for 10 fractions (3,000R) and 1.27 for 15 fractions (4,500R). The continuous administrations of UFT for one month after combination treatment suppressed the tumor regrowth. It is suggested that UFT is a useful radiosensitizer for concurrent fractionated radiation and useful adjuvant agent after radiation therapy.

Animals↗

[Experimental studies on the combined effect of radiation and UFT 1. Radiosensitizing effect of UFT under single X-ray exposure].

The combined effects of X-ray and UFT, which is a mixture of tegafur (FT) and uracil, were studied using C3H mouse mammary carcinoma. Tumors were irradiated with a single dose of 1,000 R, 2,000 R one week after intramuscular transplantation. UFT (FT 15mg/kg+Uracil 33.6mg/kg) was intragastrically administered 2 hours before irradiation. In the group treated by combination of UFT and 1,000 R, the dose modifying factor (DMF) of UFT was 1.28 on the tumor growth delay and 1.64 on the survival time. A decrease in pulmonary metastases was found in the group treated by combination of UFT and radiation. It is suggested that UFT is a useful oral drug for combined treatment with radiation.

Animals↗

[Experimental studies of multiple fractions per day (MFD) at smaller doses than 2 Gy].

Effects of twice daily fractionations (B.I.D.) at smaller doses per fraction than 2 Gy on mammary carcinoma of C3H/He mouse (alpha/beta ratio = 15-20 Gy) were studied. Sixty percent doses of conventional fractionations (Q.D.) were irradiated twice daily with 4 hours interval. Though B.I.D. at 120 R, 150 R were less effective than Q.D. at 200 R, 250 R, B.I.D. at 180 R were more effective than Q.D. at 300 R, equivalent to the increments of the total doses. B.I.D. at smaller doses than "flexure dose" (not equal to 0.1 x alpha/beta) seemed to be less effective for tumors. Human tumors transplanted to nude mice might be useful to study therapeutic gain ratio.

Adenocarcinoma↗

Radiation therapy for stage I and II laryngeal cancer using 10 MV X-rays or cobalt-60 gamma-rays.

From 1970 to 1985, 117 patients with stage I and stage II carcinoma of the larynx (98 with glottic, 15 with supraglottic, and 4 with subglottic cancer) received radiation therapy. The patients were treated with (1) a 60Co machine equipped with 45-degree wedge filters, at a total dose of 6,000-7,000 cGy, 300 cGy per fraction, 3 days a week in the period from 1970-1974; (2) 10 MeV linear accelerator X-rays from 1975-1980, and (3) 10 MeV linear accelerator X-rays and/or the 60Co machine in the period from 1981-1985, at a total dose of 6,000-7,000 cGy, 5 days a week by parallel opposing portals without wedge filters. The 5-year local control rates by radiotherapy alone were 66%, 78%, and 83%, respectively, in the three periods, and the 5-year survival rates were 77%, 97%, and 96% following salvage surgery for recurrent disease. In the 1970-1974 period, four patients developed severe laryngeal edema, and two patients had total laryngectomy without local residual tumor. In the 1975-1985 period, 16 patients had local recurrence in five years, and in five of them the tumor exhibited verrucous-like histopathological findings. In the 1975-1980 period, local recurrence was considered to result from underdosing of lesions with 10 MV X-ray beams and split-course irradiation. In the last five years of the period, the 5-year local control rate for stage I and II carcinoma of the glottis, excluding verrucous-like carcinoma, reached 90% with 10 MV X-rays combined with 60Co gamma-rays.

Adult↗

Dedifferentiated chordoma arising in irradiated sacral chordoma.

A patient who received radiation therapy for a sacral lesion 10 years ago and eventually developed dedifferentiated chordoma at the primary site is reported. Initially, the patient received 54 Gy with Co-60 to the sacral tumor, and 6 years later an additional 50 Gy with 10 MV X-rays to the local recurrence. Four years later, an evident sacral tumor was noticed. When readmitted for re-confirmation of histology, a large rapidly growing lung metastasis was observed. The patient eventually died of progressive disease with incidental aspiration pneumonia. At autopsy, 10 years after the initial treatment, the recurrent sacral tumor proved to be dedifferentiated chordoma accompanied by typical chordoma. Although this case suggests the possible malignant transformation of chordoma rather than collision, the factors inducing this change remain unknown.

Chordoma↗