Safety and efficacy of ultrasound-guided microwave ablation in patients with primary hyperparathyroidism: a single-center retrospective study

Background: Ultrasound (US)-guided microwave ablation (MWA) for primary hyperparathyroidism (PHPT) is a relatively novel minimally invasive treatment. However, definitive evidence for the efficacy of thermal ablation in treating PHPT is not well characterized. This work aimed to evaluate the effectiveness and safety of US-guided MWA in patients with PHPT. Methods: This retrospective study analyzed the data of patients diagnosed with PHPT who underwent US-guided MWA at Peking University First Hospital between October 2020 and October 2024. Serum levels of parathyroid hormone (PTH), calcium, and phosphate were measured preoperatively and at 3, 6, and 12 hours post-MWA to assess immediate biochemical changes. Long-term therapeutic outcomes were evaluated by monitoring the volume of ablation areas and serum PTH, calcium, and phosphate levels at 1, 3, 6, and 12 months post-MWA or at the last follow-up. Results: A total of 30 clinical records were reviewed, of which 25 (15 female and 10 male; mean age: 60.04±17.38 years) met the inclusion criteria and were included in the final analysis. No clinically significant complications were observed during or following the MWA procedure. Serum PTH levels showed a significant reduction at 3, 6, and 12 hours post-MWA compared to baseline. Serum calcium levels began to decrease significantly at 3 hours post-MWA, whereas serum phosphate levels showed no significant changes within the first 12 hours. Serum PTH levels were significantly lower at the last follow-up (mean duration: 7.48 ± 4.8 months) compared to baseline (P=0.002). Serum calcium levels were significantly lower at 1 month and at the last follow-up (P=0.0021) compared to baseline. At the last follow-up, the volume reduction ratio (VRR) of the ablated masses was 71.5%±29%. Conclusions: Our study provides evidence that US-guided MWA is safe and effective for managing PHPT adenomas.