Mobile continuous kidney replacement therapy for appropriate radioactive iodine administration in a hemodialysis patient: a case report

Background Radioactive iodine (RAI) therapy is an important adjuvant treatment for differentiated thyroid cancer following thyroidectomy. In patients with end-stage kidney disease (ESKD), including those on hemodialysis, the reduced renal excretion increases the risk of prolonged retention. Moreover, contamination of dialysis equipment and dialysate poses serious safety concerns. Despite these risks, clinical guidelines for the management of RAI therapy in this patient population are lacking. We report a case in which a mobile continuous kidney replacement therapy (CKRT) device was used as an alternative to a conventional hemodialysis apparatus, providing distinct safety advantages. Case presentation A 36-year-old Japanese man with ESKD on maintenance hemodialysis was diagnosed with high-risk papillary thyroid carcinoma and underwent total thyroidectomy with lymph node dissection. Postoperative RAI therapy was administered twice, at doses of 555 megabecquerel (MBq) and 1110 MBq, respectively. Hemodialysis was conducted in a radiation isolation room using a mobile CKRT device. This system allowed bedside dialysis using fully replaceable circuits, thereby minimizing contamination risk and ensuring the safe disposal of radioactive waste. Exposure rate at 1 m (ER-1m) was reduced by 46% to 62% before and after each dialysis session. Radiation exposure of medical staff remained within acceptable limits, and no adverse events occurred. Follow-up scintigraphy confirmed the resolution of radioactive uptake. Conclusions This case highlights the feasibility and safety of administering RAI therapy in a patient undergoing hemodialysis using a mobile CKRT device in an isolation room. This strategy may serve as a practical alternative to standard hemodialysis in similar clinical contexts.