Tolerability and Long-Term Safety of Gadolinium-Based Contrast-Enhanced Interstitial Pedal MR Lymphangiography in...

Contrast-enhanced MR lymphangiography (CE-MRL) with pedal interstitial injection of a gadolinium-based contrast agent is increasingly employed in patients with lymphedema (off-label use). However, data on short-term tolerability and possible long-term adverse effects are limited. This study aimed to report clinical experiences regarding the tolerability and long-term safety of CE-MRL.

A total of 168 patients (36 male; mean age 49.1±16.4 y) with clinically diagnosed lymphedema underwent clinically indicated CE-MRL. A total of 8 mL of diluted MR contrast agent (6 mL 1.0 mmol/mL Gadobutrol, 2 mL saline solution) was prepared. After intradermal administration of 0.2 mL local anesthetic, 1 mL of this contrast agent solution was injected intradermally into each interdigital space. To assess tolerability, patients were asked after the examination about their experience regarding remaining motionless during the examination, confinement in the MRI scanner, interdigital contrast injection, and the overall experience [5-point Likert scale (1: very easy/well tolerable, 5: very difficult/intolerable)]. Adverse events were systematically recorded during a clinical follow-up visit (≥3 mo after CE-MRL) through direct patient inquiry and inspection of the injection sites.

CE-MRL was technically successful in all cases. Mean clinical follow-up was 36±19 months (range: 3 to 81 mo). The ease of remaining motionless was rated as very easy or mostly easy in 98.2% of cases, the tolerability of confinement in the MRI scanner as well as tolerable or mostly tolerable in 97.6%, the contrast injection in 85.1%, and the overall experience in 97.6%. In addition, 95.8% of patients would recommend CE-MRL under similar conditions. Five patients reported transient irritation of the skin (n=3, 1.8%) and/or light interdigital pain (n=3, 1.8%) for 1 or 2 days at the injection site. No other adverse events were observed.

CE-MRL is well tolerated and safe. Intradermal interdigital contrast injection was the most uncomfortable part of the examination, but was still well tolerated by most patients without any long-term adverse events.