Radiotherapy for rejection of renal transplant allografts refractory to medical immunosuppression

OBJECTIVE: To evaluate the outcome and prognostic factors of patients who underwent local graft irradiation for acute renal allograft rejection refractory to modern immunosuppressive medications. METHODS: From 1996 to 2005, 33 patients received local graft irradiation (LGI), with 3 patients receiving 2 courses of radiation. Graft rejection was diagnosed when a rise in creatinine prompted a renal biopsy that demonstrated acute allograft rejection. Upon failure of medical immunosuppresion to resolve rejection, patients were then referred by the organ transplant team for LGI. The median dose was 800 cGy (range, 600-800 cGy), and was given in 200 cGy fractions generally using AP/PA fields. A retrospective review was conducted to determine dialysis-free survival, defined as the date from initiation of radiation therapy to date of hemodialysis placement, and to analyze potential factors that may predict dialysis free survival. RESULTS: Median follow-up from date of radiation therapy to date of last follow-up was 25 months (range, 0.9-99.4 months). The median time between allograft transplantation and radiation therapy was 17.8 months. For the entire group of patients, 20.6% were alive with a functioning graft. The median dialysis-free survival for the entire group was 3.8 months. The median dialysis-free survival for those patients not on dialysis at time of irradiation versus those patients on dialysis was significantly different (5.6 versus 0 months, P = 0.02). CONCLUSION: In renal allograft transplant recipients who experienced acute rejection episodes refractory to modern chemical immunosuppression, LGI was well tolerated and remains a viable salvage treatment option.