Three-dimensional Conformal Radiotherapy for Localized Prostate Cancer in Kidney Transplant Recipients

Background: This is the first report of graft function and prostate cancer control in renal transplant recipients subjected to modern conformal radiotherapy.

Methods: Eight kidney transplant recipients were treated with three-dimensional conformal radiotherapy. All patients but one were subjected to transitory hormonal deprivation. A three-dimensional radiotherapy-planning system (Pinnacle, Philips Medical System, Bothell, WA) was used to delineate anatomic contours on pretreatment computed tomography and for dose computation. The clinical target volume encompassed the prostate and was expanded with a 10-mm wide margin in all directions to obtain the planning target volume. The irradiation technique consisted of a nine-field arrangement delivering 70 Gy in 2-Gy fractions, with 18-MV photon beams. Biochemical recurrence was defined as two consecutive increases in prostate-specific antigen (>1.5 ng/mL). Graft function was monitored by creatinine clearance. Excretory profiles were assessed by furosemide-stimulated diethylenetriaminepentaacetic acid renography. All patients were subjected to hip magnetic resonance imaging to assess for avascular hip necrosis.

Results: After a mean follow-up of 28 months, two patients showed isolated biochemical recurrence and six patients remained free of recurrence. In seven patients with functional allografts, the creatinine clearance was unimpaired by treatment. However, significant obstruction of the terminal ureter was revealed in two patients by furosemide-stimulated diethylenetriaminepentaacetic acid renograms. The doses delivered to the uretero-neocystostomy were calculated to range from less than 20 Gy to more than 45 Gy depending on bladder repletion.

Conclusions: Adequate cancer control was achieved at the expense of infraclinical ureteral obstruction. The doses delivered to the uretero-neocystostomy may be reduced by having a full bladder at the time of irradiation. No avascular hip necrosis was observed.