Radioiodine I-131 ablation therapy and impaired renal function: Possible impact on guidelines.

Abstract

e17591 Background: Sodium iodide (I-131) is eliminated predominantly through renal clearance. There is no consensus on the ideal dose of I-131 to be administered for patients with impaired kidney function. We aim to compare the rate of I-131 clearance in patients with impaired to those with normal renal functions. Methods: 27 cases (34 treatments) of differentiated thyroid cancer and eGFR 15-59 ml/min/1.73 m2 received I-131 (mean dose of 150 mCi) for remnant ablation between 2010 and 2016. Another 34 patients matched for age, gender, weight and I-131 dose with eGFR ≥ 60 ml/min/1.73 m2 were selected as controls. Endpoints of interest were (a) Length of hospital stay (LOHS) until the patient’s I-131 activity declines to < 30 mCi (b) Exposure rate measured by Geiger counter 0 to 48 hours after treatments (ER 48). Paired t-test was used to compare both groups. Results: Mean LOHS for cases vs. controls was 2.47 vs. 2 days respectively (P = 0.007). Results of ER 48 were available and matched in 18 cases and controls. Mean ER 48 for cases vs. controls was 3.74 vs. 1.8 mR/h respectively (P = 0.002). The mean proportional reduction of exposure rate after 48 hours compared to hour 0 for cases and controls was (-88% vs. -92.6%, P = 0.008), (-93.5% vs. -94.5%, P = 0.5) and (-67.2% vs. 94.3%, P = 0.04) for eGFR 46-59 (n = 13), 30-45 (n = 3) and 15-29 ml/min/1.73m2 (n = 2) respectively. Conclusions: Patients with impaired renal function are subject to longer hospital stay and delayed renal clearance of the tracer with consequent increased radiation exposure. Guidelines should consider adjusting the dose of I-131 in these patients to avoid possible harmful effects of excess I-131 on vital organs.

Safe use of radiopharmaceuticals in patients with chronic kidney disease: a systematic review

“…After a full-text screening we excluded another 31 studies for various reasons: they gave no relevant information on dosing or aspects related to dosing ( n = 18), they addressed only the radiation safety of staff ( n = 5), described renal imaging ( n = 5), or were review ( n = 3). A total of 34 studies remained for inclusion in this systematic review (Akers et al 2016 ; Aktaş et al 2008 ; Alevizaki et al 2006 ; Bhat et al 2017 ; Courbon et al 1997 , 2006 ; Culpepper et al 1992 ; Daumerie et al 1996 ; Demko et al 1998 ; Driedger et al 2006 ; El-Zeftawy et al 2017 ; Fofi et al 2013 ; Holst et al 2005 ; Howard and Glasser 1981 ; Jiménez et al 2001 ; Kaptein et al 2000 ; Kode et al 2017 ; Laffon et al 2008 ; Magné et al 2002 ; McKay and Malaroda 2019 ; McKillop et al 1985 ; Mello et al 1994 ; Minamimoto et al 2007 ; Miyasaka et al 1997 ; Morrish et al 1990 ; Pahlka and Sonnad 2006 ; Sinsakul and Ali 2004 ; Tobes et al 1989 ; Toriihara et al 2015 ; Toubert et al 2001 ; Vermandel et al 2020 ; Wang et al 2003 ; Willegaignon et al 2010 ; Yeyin et al 2016 ). The selection process is illustrated in a PRISMA flow diagram (Fig.…”

“…The latter study described the treatment of 27 patients with [ 131 I]sodium iodine for ablation after thyroid cancer and reported a longer hospital stay and delayed renal clearance. It concluded that guidelines should consider adjusting the dose of [ 131 I]sodium iodine in these patients to avoid increased radiation exposure (El-Zeftawy et al 2017 ), but it did not specify the exact adjustment needed.…”

“…Although the findings for therapeutic radiopharmaceuticals were limited, some studies indicated that dose adjustments in patients with CKD are important, and that altered biodistribution does affect therapeutic response and the risk of toxicity for non-target organs. A non-optimised dose in patients with CKD may lead to inadequate treatment (Aktaş et al 2008 ), increased radiation exposure (El-Zeftawy et al 2017 ), or an increased risk of adverse effects (for example, bone marrow toxicity, xerostomia, epistaxis, sialadenitis, or xerostomia from treatment with [ 131 I]sodium iodine) (Aktaş et al 2008 ; Alevizaki et al 2006 ; Holst et al 2005 ; Vermandel et al 2020 ).…”