Modified Dose of Radioactive Iodine Therapy in a Patient With Thyroid Cancer on Peritoneal Dialysis: Case Report and Review of Literature

Thyroid malignancy is common among patients with renal impairment compared with the general population. Treatment involves surgical resection and radioactive iodine therapy (RAI) in high-risk patients. As a result of impaired iodine clearance in those with no residual kidney function, the determination of appropriate iodine dose is challenging. Evidence is lacking, and all previous reports are based on case studies with no universally accepted protocol. We describe the case of a 30-year-old woman with end-stage renal disease on peritoneal dialysis (PD) who was diagnosed with papillary thyroid cancer while undergoing a pre-kidney transplant workup. She had a total thyroidectomy with modified radical neck dissection followed by a reduced-dose radioactive iodine therapy of 30 mCi based on her residual kidney function. Her PD prescription was adjusted to achieve a 2 L ultrafiltration daily. One year follow-up confirmed no evidence of residual nor recurrent disease. High-risk patients with differentiated thyroid malignancy require adjuvant radioactive iodine therapy. The optimal dose of RAI in the end-stage renal disease population is controversial. There are no clear guidelines available for patients with end-stage kidney disease including patients on peritoneal dialysis. Reduced dose therapy is probably effective in achieving the goals of therapy, with lower toxic risk to internal organs. Determining the appropriate schedule of each dialysis session in relation to RAI, the specific replacement prescription, and establishing a safe environment for medical staff dealing with such patients is important to consider. This article aims to highlight the need to establish a standardized protocol among patients with reduced kidney function treated with iodine therapy.