Imaging description

Radiation nephropathy (or nephritis) refers to the renal damage that may develop months to years after therapeutic radiation that includes all or part of the kidneys. At CT or MRI, radiation nephropathy initially appears as delayed or persistent enhancement in the irradiated portion of the kidney with later development of renal atrophy or caliectasis [1–4]. These changes may be seen at CT or MRI (Figures 40.1–40.4), and are most frequently seen in the medial aspect of the upper poles of both kidneys after radiation therapy of the retroperitoneum or spine (the upper poles are preferentially affected because they lie closer to the midline). Other patterns of involvement may be seen depending on the radiation field.

Importance

It could be argued that radiation nephropathy is of little clinical relevance because it is unlikely to be mistaken for serious pathology and often goes unrecognized. That said, recognition of radiation nephropathy remains of importance because it indicates a history of malignancy and may prompt closer scrutiny of the images for recurrent disease or other therapy-induced complications.

Typical clinical scenario

Radiation nephropathy is seen only in patients who have been irradiated for malignant disease, and may develop in the months or years after upper abdominal radiation that includes the kidneys in the radiation field, and persist indefinitely.