Ultrasound guided ethanol injection for the treatment of parathyroid adenoma A prospective self controlled study

Parathyroidectomy, the standard treatment of primary hyperparathyroidism (PHP) due to parathyroid adenoma, is not suitable for all patients. We evaluated the efficacy of ultrasound‑guided ethanol ablation of parathyroid adenoma in a group of patients with PHP.

In a prospective self‑controlled trial, 39 patients with parathyroid adenoma, who were not candidates for surgery, were enrolled. Ethanol injections were performed by two experienced interventional radiologists under the guidance of real‑time ultrasonography. Adenoma size changes were assessed at about 1 month later. Serum levels of parathyroid hormone, calcium, phosphate, 25‑OH Vitamin D, and alkaline phosphatase were evaluated at the baseline, 1, 3, 6, and 12 months after the injections. The treatment effects on outcome variables were assessed by repeated measures analysis.

Volume of the adenomas decreased during the study period from 1.87±6.45 cm3 to 0.38± 0.48cm3 (P < 0.001). Corrected serum calcium levels decreased from 10.40 ± 0.96 mg/dl to 8.82 ± 0.58 mg/dl (P < 0.001), and remained stable during one year follow‑up. Serum levels of parathyroid hormone decreased gradually from 129.85 ± 63.37 to 72.58 ± 53.86 pg/mL after 3 months and to 44.78 ± 28.04 pg/mL after 1 year (P < 0.001). Overall, 46% of the patients improved after 1 month of ethanol ablation therapy which increased to 84.5% during 1‑year follow‑up. No major complications were observed.

The current study showed the efficacy of ultrasound‑guided ethanol injection in PHP and may be considered as a suitable alternative treatment in patients who are not candidates for the surgery. It has also a good safety profile without major complications if performed by experienced hands.