Efficacy of Ultrasound-guided Radiofrequency Ablation of Parathyroid Hyperplasia: Single Session vs. Two-Session for Effect on Hypocalcemia

Abstract

To evaluate safety and efficacy of one-vs. two-session radiofrequency ablation (RFA) of parathyroid hyperplasia for patients with secondary hyperparathyroidism (SHPT) and to compare the outcome of both methods on hypocalcemia. Patients with secondary hyperparathyroidism underwent ultrasound guided RFA of parathyroid hyperplasia. Patients were alternately assigned to either group 1 (n = 28) with RFA of all 4 glands in one session or group 2 (n = 28) with RFA of 2 glands in a first session and other 2 glands in a second session. Serum parathyroid hormone (PTH), calcium, phosphorus and alkaline phosphatase (ALP) values were measured at a series of time points after RFA. RFA parameters, including operation duration and ablation time and hospitalization length and cost, were compared between the two groups. Mean PTH decreased in group 1 from 1865.18 ± 828.93 pg/ ml to 145.72 ± 119.27 pg/ml at 1 day after RFA and in group 2 from 2256.64 ± 1021.72 pg/ml to 1388.13 ± 890.15 pg/ml at 1 day after first RFA and to 137.26 ± 107.12 pg/ml at 1 day after second RFA. Group 1's calcium level decreased to 1.79 ± 0.31 mmol/L at day 1 after RFA and group 2 decreased to 1.89 ± 0.26 mmol/L at day 1 after second session RFA (P < 0.05). Multivariate analysis showed that hypocalcemia was related to serum ALP. Patients with ALP ≥ 566 U/L had lower calcium compared to patients with ALP < 566 U/L up to a month after RFA (P < 0.05). Group 1's RFA time and hospitalization were shorter and had lower cost compared with Group 2. US-guided RFA of parathyroid hyperplasia is a safe and effective method for treating secondary hyperparathyroidism. Single-session RFA was more cost-effective and resulted in a shorter hospital stay compared to two sessions. However, patients with two-session RFA had less hypocalcemia, especially those with high ALP.Secondary hyperparathyroidism (SHPT) commonly occurs in patients with end stage renal disease (ESRD) when low calcium levels and high phosphorus levels over time stimulate increased PTH secretion 1-3 . SHPT increases the risk for osteoporosis and kidney stones, as well as for parathyroid hyperplasia, a condition that can cause mental abnormalities, renal osteodystrophy, calcific uremic arteriolopathy, vascular calcification, muscle spasms and even lead to respiratory or cardiac arrest 4 .Treatment for SHPT includes vitamin D sterols, intravenous vitamin D analogs and cinacalcet 5-10 to improve biochemical profiles and other surrogate markers 11 . Patients with severe SHPT may be candidates for parathyroidectomy (PTX), which increases long-term survival and reduces the risk of fracture in ESRD patients 12 . However, hyperparathyroidism recurs in up to 30% of patients treated with PTX due to incomplete excision of all hyperplasic parathyroid glands 13,14 . Meanwhile, PTX can potentially result in permanent hypoparathyroidism if the parathyroid glands are over-excised 15 .

Hypocalcemia after ultrasound-guided microwave ablation and total parathyroidectomy for secondary hyperparathyroidism: a retrospective study

“…As TPTX removes all four parathyroid glands to reduce the risk of secondary resection, ultrasound-guided MWA for SHPT completely inactivates the hyperplastic glands which can be displayed on ultrasound. Since the two surgical methods and treatment strategies are completely different, MWA sometimes requires multiple sessions to achieve the treatment purpose [23]; the level of PTH may fluctuate during the follow-up, resulting in postoperative serum calcium value fluctuation. Persistence and/or recurrence SHPT was more common in thermal ablation [9].…”

Radiofrequency Ablation for Benign Thyroid Nodules: Efficacy According to the Types of Thyroid Nodules

“…US-guided RFA was performed using grey-scale imaging with a iU22 US scanner and a highfrequency linear probe (L12-5) (Philips, The Netherlands), while contrast-enhanced ultrasound (CEUS) with a high-frequency linear probe (L9-3) was used to monitor the RFA procedures ( Fig. 2A, 2D), as well as the initial diagnostic evaluation and the follow-up 11 . All patients were studied with US before the treatment by one of two radiologists (Kefei Cui and Yuanjing Huang) enrolled in the study, with 35 and 20 years of thyroid US experience, respectively.…”

Ultrasound-Guided Radiofrequency Ablation: A New Attempt to the Treatment of Refractory Hyperparathyroidism Secondary to Chronic Kidney Disease

“…Therefore, a less invasive therapeutic intervention with greater efficacy and shorter recovery period is required for patients with refractory SHPT. Radiofrequency ablation (RFA) is a minimally invasive, non-surgical procedure that increasingly being used to treat refractory hyperparathyroidism and achieve clinical affirmation [7,8] . However, no study so far has compared the clinical efficacy and safety of surgery and RFA for the treatment of refractory SHPT.…”