Etiology, clinical manifestations and prognosis of the radiation nephritis

If the irradiation field of a megavoltage therapy extends over one kidney or a part of it, blood pressure reactions suggest in some cases an affection of the kidney. These reactions may already accur after doses of 5 to 20 Gy. After higher doses, a number of symptoms may appear which have been classified into three clinical groups by Sarre and Moser and even into five groups by Luxton and Kunkler. They show histologic manifestations in the glomeruli and tubuli and are mostly progressive. In case of radiotherapy alone, the threshold doses are 20 to 25 Gy. After a latent time of several months, these patients may present renal insufficiency and hypertonia, leading eventually to death in an acute stage, chronic development with preponderant renal insufficiency, hypertonia, or incomplete healing. These doses are considerably lower in children. It has been proved recently that these threshold doses are considerably reduced by combined chemotherapy too, even if the cytostatic drugs alone have no nephrotoxic potential. This is verified by our experimentations on animals. If only a little part of the kidney is situated within the irradiation field, e.g. the upper renal pole in case of an irradiation of the spleen, a significantly reduced activity in the upper pole of the left kidney can be proved by scintigraphy after a period of eight months. After about 18 months, tomography shows a cortical atrophia in this region. However, as far as clinical or technical examinations are concerned, no abnormal parameters could be found. (orig.)