The long-term effects of X irradiation in patients treated for metropathia haemorrhagica

Long-term effects of irradiating a small part of the body with X rays were observed in 2,068 patients whose ovaries were irradiated to produce an artificial menopause. Ninety-seven per cent of the patients were treated for metropathia haemorrhagica and the remainder for other benign gynaecological disorders. The patients were treated at three Scottish Radiotherapy Centres between 1940 and 1960 and were followed to January 1, 1964. Fourteen (0·7 per cent) could not be traced and 245 (11·8 per cent) were found to have died. The numbers of deaths from different causes were compared with the numbers expected in a similar population exposed to the Scottish national mortality rates over the same period. Five or more years after treatment, the observed mortality was greater than expected for leukaemia (six deaths against 1·0) and for cancers of other directly irradiated sites (31 deaths against 18·4); it was less than expected for cancer of the breast (five deaths against 10·5) and close to that expected for other cancers, coronary thrombosis and other causes. The average mean marrow dose was estimated at 136 rads. Previous observations on subjects who received more widespread irradiation suggest that this dose would produce about six cases of leukaemia in 10 to 20 years. The results are, therefore, consistent with the hypothesis that the risk of leukaemia induction is proportional to the total energy absorbed in the marrow irrespective of the volume irradiated.