泌尿器科領域に於ける放射性同位元素の研究(第4報) コバルト60遠隔照射による膀胱癌の治療に関する臨床的・実験的研究

Abstract

From the experience of treating 21 cases of the bladder tumor, which are in different grades and stages, with external irradiation using 250 curie 60Co source, following conclusions were obtained. 1. So f a r as the relation between tumor doses over all time and clinical results concerns, the method of choice is administration of 5000-7000γ. in 5-8 weeks. 2. Conspicuous degeneration and karyolysis of tumor cells are de m onstrated in the cases treated with dose over 4000γ.. No specific difference in radiation sensitivity was noted in various types of tumor cells by radiation of 60Co. 3. Careful consideration must be paied to the count o f W.B.C. and behavior of potassiummetabolism during radiation treatment. Three of eight patients , who were given over 40001., revealed hypokaliemic syndrome in the course of treatment . 4. External irradiation of the direct exposed bladder opened 4 c m. long at the abdominal wall after carrying out urinary diversion has the advantage that location of the tumor in the evacuated bladder can be indicated exactly on an x-ray film by a silber wire pre viously stiched around the base of the tumor and accurate beaming of the tumor is possible. Direct observation of the radiation effect and frequent biopsies during treatme nt are also possible. Experimental irradiation of the bladder using 40 curie 60Co source was carried out in fourteen adult mongorel dogs with a daily increment dose of 300 r. to the bladder (measured at 4 cm below the skin surface). A total dose of 3000 γ. and 5000 γ. was delivered to four dogs, and 8000 γ. to six dogs respectively . Biopsies were done three times , that is, immediately, three months and six months after irradiation . The radiation effects were studied by the histological examination and following conclusions were obtained . 1. Immediately after irradiation the 3000 γ. group shows slight degeneration and partial exfoliation of the epithelial cells. Remarkable dilation of the submucous capillaries is seen. In 5000 γ. and 8000 γ. group, the greater part of the epithelium is exfoliated, remaining only the basal membrane. Submucous congestion is more extensive. 2. Three months later, 3000 γ. group shows regeneration of epithelium in several layers and submucous tissue appears to be atrophic. In the 5000 γ. group, exfoliation of epithelium still remains, but shows partial regeneration of epithelium. In the 8000 γ. group, regeneration of the epithelium is hardly found. 3. Six months later, the 8000 γ. group shows partial regeneration of epithelium. 4. Concerning the mesenchymal tissues, few changes are observed i n the 3000 γ. and 5000 γ. group. In the 8000 γ. group, both three and six months' specimen reveal increasing of connective tissue and wandering of the fibroblasts which signify formation of the granulation tissue.