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Biomedical subjects

O Mendiondo

Publications and source records attributed to O Mendiondo.

6 recordsLinked to original sources

Relative biological effectiveness of modulated proton beams in various murine tissues.

The relative biological effectiveness (RBE) of proton beams produced by Harvard University 160 MeV synchrocyclotron was studied in various murine tissues. Reference radiation was Cobalt-60 gamma-rays from a teletherapy unit at the Massachusetts General Hospital. Animals were C3Hf/Sed mice derived from our defined flora mouse colony. Test tissues are: lens, lung, testes and tail vertebrae. The RBE of the third generation isotransplants of a spontaneous mouse mammary carcinoma was also investigated. The proton and Cobalt-60 irradiations were carried out simultaneously by 2 teams. The dose response curves obtained for testes weight loss and growth stunting of tail vertebrae indicated that the RBE for our protons was independent of radiation dose in the range of 0.4 to 16 Gy. This finding was identical to our previous studies of the murine fibrosarcoma, skin and small intestine. The RBE values for lens and lung tissues were obtained by determining radiation dose to result in a complete cataract in half the irradiated eyes in 210 days and a 50% mortality in 180 days respectively. We have studied proton RBE in 7 normal tissues and 2 tumors including previously reported results. The RBE values for these tissues were found to fall between 1.09 and 1.32. No significant differences in the proton RBE were found between the several normal and tumor tissues studied.

Animals↗

Treatment of inoperable non-small cell carcinoma of the lung with radiation therapy, with or without levamisole. A randomized trial of the Southeastern Cancer Study group.

In a randomized trial, 251 patients with inoperable non-small cell lung cancer received radiation therapy (RT) with or without levamisole (2.5 mg/kg twice weekly for 1 year, or until progression). Radiation therapy was delivered to 6000-6500 rad for Stages I and II, and 4000-4500 rad by continuous or split course for Stage III disease. Responses were observed in 40% of patients receiving placebo, and in 29% of patients taking levamisole. Relapse occurred at local sites only in 53% of the placebo- and 75% of the levamisole-treated patients. The frequency of relapse in distant sites was lower (25%) in the levamisole group as compared with the placebo group (47%). No significant difference in survival was observed between the placebo and levamisole-treated groups (median survival, 48.2 and 45 weeks, respectively). Responders to radiotherapy survived significantly longer than nonresponders (median survival, 73 vs. 33.3 weeks, p = 0.001). Among responders, the median survival of patients treated with levamisole was shorter (63.9 weeks) than that of patients receiving placebo (92.7 weeks). Toxicity attributable to levamisole included severe granulocytopenia in five patients and severe nausea and vomiting in nine. It is concluded that levamisole is without significant benefit in this setting.

Adenocarcinoma↗