Lipiodol marking for CT-guided radiofrequency ablation of adrenal aldosterone-producing adenomas: a case series

Tumor visualization during computed tomography (CT)-guided radiofrequency ablation (RFA) of adrenal adenomas is often limited by the small size of the lesion and needle-induced artifacts. These limitations can impair accurate needle placement and increase the risk of incomplete ablation. This report shows four adrenal RFA procedures in which iodized oil (Lipiodol®) marking enhanced lesion visibility.

CT imaging and adrenal venous sampling showed unilateral right aldosterone-producing adenomas measuring 10-20 mm in patients with primary aldosteronism. Contrast enhancement of the nodules was confirmed via CT angiography after microcatheter insertion into the adrenal artery. Transarterial embolization was performed utilizing a 1:1 mixture of Lipiodol and iohexol. In three cases, Lipiodol deposition within the adenomas was confirmed on CT immediately post-embolization and persisted on the following day. Despite needle-induced artifacts during RFA, nodule visibility significantly improved. RFA was completed without major complications, which resulted in the resolution of primary aldosteronism and hypertension. In one case, although Lipiodol marking was discontinued due to the extravasation from the adrenal artery branch, RFA was completed on the following day.

CT-guided RFA with Lipiodol marking facilitated the effective treatment of aldosterone-producing adrenal adenomas in three patients by significantly enhancing lesion visibility. Adrenal arterial embolization should be addressed with caution to avoid damaging the small blood vessels of the adrenal gland.