DR BABITHA SELVANANTHAN1, Dr RAYMOND LIN1, ALESSANDRA MALARODA2, WILLIAM RYDER2, VERONICA WONG2, DR BHADRAN BOSE1, DR NIKKI WONG1
1Department of Renal Medicine, Nepean Hospital , Kingswood, Australia, 2Department of Nuclear Medicine and PET, Nepean Hospital, Kingswood, Australia
Background: Radioactive iodine (RAI) is an established treatment for thyroid carcinoma following thyroidectomy. I-131 is predominantly excreted renally hence its clearance is reduced in patients with end-stage kidney disease (ESKD). There are, however, no established protocols for dosing in this population aimed at balancing treatment efficacy with red marrow toxicity. Studies in the dialysis population have modelled I-131 distribution in thyroid tissue and bone marrow, and its clearance from the body; however limited evidence exists to guide dosing, dialysis timing, or duration of isolation following the initial RAI dose. There is therefore a need to understand the real-world kinetics of I-131 in relation to haemodialysis, in order to optimize treatment efficacy whilst minimizing radiation hazard to the patient and dialysis staff.
Case Report: We report two haemodialysis patients undergoing RAI therapy for papillary thyroid carcinoma. A protocol was created by a multidisciplinary team comprising of medical physicists, nuclear medicine physicians, nephrologists and dialysis nursing staff. Modifications to haemodialysis included pre-treatment training in self-cannulation, implementation of haemodialysis in an unplumbed lead-lined room, and safe isolation and disposal of haemodialysis equipment. I-131 dosing was individualized accounting for patient weight, residual renal function, as well as capacity to safely suspend dialysis.
Conclusions: Our protocol introduced the use of measuring I-131 levels in blood to monitor for red marrow toxicity, whilst one-meter dose-rate measurements were used to determine safety for release. Our report additionally provided a comparison between an anephric (bilateral nephrectomy) patient and a haemodialysis patient with residual renal function, characterizing the clearance of I-131 solely by haemodialysis. Our protocol may be useful in informing future RAI therapy in haemodialysis patients.
Biography:
Dr Babitha Selvananthan is a Renal Advanced Trainee in the Western Sydney Local Health District. She completed her Bachelor of Medical Sciences and Doctor of Medicine with Distinction at the University of New South Wales. Dr Selvananthan has a particular interest in delaying the progression of chronic kidney disease and glomerulonephritis.