Iodine 131 treatment for differentiated thyroid carcinoma in patients with end stage renal failure: dosimetric, radiation safety, and practical considerations.

BACKGROUND Iodine 131 ablation following total thyroidectomy is considered an indispensable element of successful treatment of differentiated thyroid carcinoma (Dtc). because of the essential role of the kidneys in iodine clearance, (131)I therapy of Dtc in patients with end stage renal disease, particularly those maintained on haemodialysis, present a number of special features: the (131)I activity needs to be modified, the haemodialysis sessions need to be adjusted at the time of (131)I therapy, and there are radiation safety considerations during dialysis. there is considerable controversy over these crucial questions in the reports published so far in the literature, which concern a total of fourteen patients. OBJECTIVE the aim of our study was to present our experience on (131)I treatment of 5 Dtc patients with end stage renal disease. DESIGN the data of 5 Dtc patients with end stage renal disease, treated with (131)I, were retrospectively analysed; four cases were treated for remnant ablation and one for locoregional progression. In order to allow for prolonged plasma clearance of (131)I, we used a lower activity of radioiodine, reduced to roughly 40-50% of the empirically calculated activity used for normal individuals; dialysis sessions were performed immediately before and at 48 hours after (131)I administration. All patients had (131)I retention measurements performed post dialysis; in two of them some additional measurements such as iodine clearances were also performed. RESULTS None of the patients experienced any short-term side effects, while they all had undetectable thyroglobulin levels on the first post therapy evaluation off thyroxine. (131)I elimination in the first haemodialysis was about 60%. staff incidental exposure and (131)I contamination were insignificant. CONCLUSIONS On the basis of our experience, an empiric activity of 40-50% of that used for normal individuals appears to be effective as well as safe. these encouraging findings are discussed in relation with other reports in the literature.