Invited Presentations Invited Abstracts

TC23.03 - Presentation 03 (ID 658)

Speakers
  • A. Rovira
Authors
  • A. Rovira
Presentation Number
TC23.03
Presentation Topic
Invited Presentations

Abstract

Abstract

The indication of gadolinium (Gd)-enhanced T1-weighted sequences, especially in the monitoring and prediction of the efficacy of disease-modifying treatments has raised some controversy, given the evidence regarding the deposition of this element in deep grey matter structures, which is orders of magnitude more evident in patients receiving linear compared to macrocyclic chelates. Due to this evidence, the European Commission suspended in 2017, the use of linear gadolinium-based contrast agents (GBCAs) for central nervous system MRI examinations, and recommended that Gd should only be used if essential, and at the lowest possible dose. On the other hand, the US Food and Drug Administration (FDA) indicated that the retention characteristics of each agent should be considered when choosing a GBCA for patients who may be at higher risk for Gd retention, such as those requiring multiple lifetime doses, pregnant women, children, and patients with inflammatory conditions. The FDA also stated that health care professionals should consider limiting GBCA use to clinical circumstances in which the additional information provided by the contrast is necessary, and are also urged to assess the necessity of repetitive GBCA MRIs in established treatment protocols. In MS, the policy of reducing GBCA use in MS patients in the pharmacovigilance setting is reasonable.

Gd-enhancing lesions are considered a marker of active inflammation at the time in which the scan is obtained. However, recognition of disease activity cannot rely exclusively on Gd-enhancing lesions, as this approach has a low sensitivity in detecting disease activity, due to the fact that median duration of contrast uptake in new T2 lesions is around 3 weeks, while the recommended interval between baseline and routine follow-up scans is much longer. Active T2 (new/enlarging) lesions, which reflect the permanent footprint from a previous focal inflammatory lesion that has occurred within the interval between two scans, are also considered a reliable marker of active inflammatory disease and may be superior to Gd-enhancing lesions in many clinical situations such as routine follow-up to detect subclinical disease activity, especially when the time gap between the two MRIs is longer than 3–6 months. The use of Gd should, therefore, be limited to cases where there is a need to confirm recent disease activity, particularly if a recent MRI is not available or not performed. On the other hand, the use of GBCAs seems to be unnecessary in the case of standard monitoring purposes for subclinical disease activity, as its detection can be based exclusively on the presence of active T2 lesions. This presentation will review the existing evidence in relation to the use of GBCAs for detecting disease activity, to finally establish a series of recommendations useful in clinical practice.

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