ABSTRACTS PRESENTADOS AL 11th INTERNATIONAL SYMPOSIUM "RADIONUCLIDES IN NEPHRO-UROLOGY", REALIZADO EN MONTEREY, CALIFORNIA, 13-17 MAYO 2001.

18. REASSESMENT OF THE VALUE OF SERIAL RADIONUCLIDE STUDIES IN RENAL TRANSPLANT RECIPENTS.

A Parthiban(1), MC Prescott(1), HJ Testa(1), A Tavakoli(2), H Raid(2). (1)Department of Nuclear Medicine, (2)Renal Transplant Unit, Manchester Royal Infirmary, Manchester, UK.

Radionuclide Imaging of Kidney Transplants in not routinely performed in many of the UK centres. This is mainly due to lack of concensus on imaging protocol and refinement in other monitoring techniques (e.g. imaging guided biopsy). Our renal transplant centre is one of the busiest in the UK and serial transplant scintigrams are performed routinely. With the improvement in other imaging techniques, immunosuppressive therapy, and rapid results from renal biopsy, we reviewed our use of serial scans to see if it was still appropriate under present day circumstances.

50 patients were included in the study (45 cadaveric and 5 live donor transplants). All patients had a baseline first circulation study with predetermined activity of Tc-MAG3, whitin 48 hours of transplantation to assess vascular supply and primary function and subsequent studies were performed according to the function of the kidney (at least three studies were performed in all patients and alternate day studies in poorly/moderate functioning kidneys). We use a very simple calculation of percentage of injected dose in the kidney, bladder and catheter and shape of the renogram curve to compare serial studies. 37 patients had good baseline transplant function. 13 patients had poor/moderate baseline transplant function (less than 10% of injected activity). 6 of the 13 patients had improved function in the subsequent scans. 7 patients continued to have reduced function on serial scans. In this subgroup of patients who did not improve either biochemically or clinically, transplant studies when used in conjunction with other parameters helped the clinician in their management (e.g. timing of biopsy or commencing further immunosupressants or maintaining current therapy), which would have been very difficult in the absence of serial studies. Even in kidneys with preserved function, reduction in uptake preceded complications, which is well recognized. In addition the scintigram was particularly useful in the diagnosis of urinary leaks.

We would recommend the use of serial scans in patients with continuing poor/moderate function but the use of serial studies in patients with primary good function is less clear.