A simple method of predicting progression of polycystic kidney disease by 99mTc-dimercaptosuccinic acid renal scintigraphy.
Renal scintigraphy with 99Tc-dimercaptosuccinic acid (DMSA) was used to determine the prognosis of patients with adult polycystic kidney disease. In 40 patients, DMSA renal uptake rate, serum creatinine and blood urea nitrogen (BUN) were examined in different periods, at least twice a year. These parameters were plotted on semilogarithmic paper against the course of observation period (years or months in duration). As the impairment of renal function progresses, these parameters gradually worsen, DMSA renal uptake decreases and serum creatinine and BUN elevate linearly. In the terminal stage when hemodialysis is required, total DMSA uptake decreased to less than 1%, and this paralleled the levels of 100 mg/dl of BUN and 10 mg/dl of serum creatinine. Accordingly, when linear lines of parameters are extended to those levels obtained in hemodialysis patients, the years and months which coincide on the abscissa can be accounted for when initiation of the hemodialysis is taken into consideration. Analysis of this linear relation in individual patients allows for an estimate of the progression of this disease and may assist in the determination of the effects of conservative treatment. This method also indicates that the level of DMSA uptake at the initial diagnosis is a critical factor in assessing the prognosis of the patient.