Prostate brachytherapy seed embolization to the right renal artery

Purpose: We report three cases of seed embolization to the right renal artery after iodine-125 (I-125) transperineal interstitial permanent prostate brachytherapy. Methods and materials: Case 1: A 65-year-old man presented with right flank and back pain less than 4 months after prostatic seed implantation. CT evaluation for renal stone showed a seed embedded in the lower aspect of the right kidney. Case 2: A 73-year-old man complained of painless hematuria 3 years after prostatic seed brachytherapy. CT and subsequent abdominal angiography showed a seed embolization to a lower branch of the right renal artery. Case 3: An 84-year-old man presented with gross hematuria 7 months after prostatic seed implantation. Excretory urogram and subsequent CT demonstrated the right lower renal seed migration. Results: Prostatic seed embolization to the right renal artery may cause pain and hematuria. This pattern of seed migration may be easily overlooked by imagers because it mimics renal lithiasis on cross-sectional imaging. Knowledge of prior history of permanent interstitial prostate brachytherapy and careful radiologic interpretation may help to achieve the correct diagnosis of rare renal seed migration. Conclusions: We present an additional atypical site of brachytherapy seed relocation in the right renal artery in 3 patients. This type of migration is probably secondary to pulmonary arteriovenous malformation or right-to-left cardiac shunts. Awareness of the propensity of seeds to dislodge and vigilance in imaging interpretation of prostatic brachytherapy recipients are necessary for the correct diagnosis of seed embolization.