# Safety of a Tailored Gadolinium-Based Contrast Agent Protocol Considering Excretion Pathways in Patients with Renal Impairment

## TL;DR

A tailored protocol for using gadolinium-based contrast agents in patients with kidney issues was found to be safe over 8 years, with no cases of NSF or brain deposition.

## Contribution

A new protocol for GBCA administration in renal patients based on excretion pathways and kidney function was developed and validated.

## Key findings

- No cases of nephrogenic systemic fibrosis (NSF) were observed in 288 patients over 8 years.
- No evidence of brain gadolinium deposition was found in the evaluated patients.
- Tailored GBCA use based on CKD stage and bilirubin levels was safely implemented.

## Abstract

Background/Objectives: Considering the excretion pathways and administered gadolinium dose, our institution has developed a tailored gadolinium-based contrast agents (GBCAs) administration protocol for patients with renal impairment to facilitate more rapid elimination and minimal retention of gadolinium. This study aims to evaluate the 8-year clinical outcomes and safety of this institutional protocol. Methods: This single-center retrospective study included patients with renal impairment who underwent GBCA-enhanced MRI between January 2015 and December 2022. The protocol recommended specific GBCAs and adjusted doses based on chronic kidney disease (CKD) stage and serum bilirubin levels: gadoxetate disodium was used for normal serum bilirubin level due to its dual excretion pathway, while macrocyclic agents were used for those with elevated serum bilirubin levels. During the follow-up period, occurrence of nephrogenic systemic fibrosis (NSF) and evidence of gadolinium deposition in brain tissues were evaluated. Results: A total of 288 patients (age, 64.6 ± 11.7 years; male, 64.9%) underwent 716 GBCA-enhanced MRI examinations in accordance with the institutional protocol. The cohort included 62 patients with CKD stage 4 and 131 patients with CKD stage 5 or undergoing hemodialysis. In patients with CKD stage 4 and 5 and those undergoing hemodialysis, 597 examinations were performed using gadoxetate disodium, and 119 used macrocyclic agents. No cases of NSF or gadolinium deposition in brain tissues were identified over mean follow-up intervals of 27.5 and 27.8 months, respectively. Conclusions: The tailored GBCA administration protocol, considering the excretion pathways and administered gadolinium dose, appears to be safe with respect to NSF for patients with renal impairment, and no evidence of brain gadolinium deposition was observed in the evaluated subset of patients.