US-guided high-intensity focused ultrasound as a promising non-invasive method for treatment of primary hyperparathyroidism.

OBJECTIVES

To investigate the long-term efficacy and safety of ultrasound (US)-guided high-intensity focused ultrasound (HIFU) treatment in patients with primary hyperparathyroidism (PHPT).

METHODS

In our prospective study, 13 of 72 screened patients with PHPT were eligible for HIFU treatment, which was performed in one or two sessions. Parathyroid adenoma size and function were evaluated at baseline, 1, 3, 6, 9, and 12 months after the final HIFU session.

RESULTS

In 11 females and 2 males, mean age 55.2 ± 12.41 years, the mean applied energy was 15.2 ± 7.7 kJ. Parathyroid size and parathyroid hormone decreased significantly one month after HIFU therapy (p < 0.002 and p < 0.02, respectively). Calcium concentration decreased slowly to reach significant reduction nine months later (p < 0.05). Complete remission was noted in three patients (23%) after one year, good disease control was achieved in nine (69%), and procedure was unsuccessful in one patient (8%). Number of sessions was significantly related to treatment success (p < 0.05). Transitory side effects were impaired vocal cord mobility in three patients (23.1%), subcutaneous oedema in three patients (23.1%), and a combination of both in two patients (15.4%).

CONCLUSIONS

HIFU is a promising non-invasive technique for PHPT treatment, which could serve as therapeutic alternative for selected patients.

KEY POINTS: US-guided HIFU is a new non-invasive ablative technique for parathyroid adenomas. The method is efficient and ensures good disease control in most patients. HIFU is a good alternative for patients not meeting surgery criteria. Treatment is well-tolerated with only transient side effects.