Post-surgical Persistent Hyperparathyroidism Successfully Treated with Parathyroid Radiofrequency Ablation: A Case Report

BACKGROUND

Currently, parathyroidectomy is the standard treatment for Primary Hyperparathyroidism (PHPT). Surgical treatment is often effective, although not free of complications and relapses. Minimally invasive techniques, such as Microwave Ablation (MWA) and Radiofrequency Ablation (RFA), are an alternative to surgery in selected patients. We have, herein, reported on the successful use of RFA in a patient with post-surgical persistent hyperparathyroidism.

CASE PRESENTATION

A 54-year-old woman was referred to our Center for mild hypercalcemia with exams revealing Primary Hyperparathyroidism (PHPT). Neck ultrasound and Technetium- 99 Methoxy-isobutyl-isonitrile (99mTc-MIBI) scintigraphy scanning revealed a suspicious right parathyroid hyperplasia/adenoma. She underwent parathyroidectomy and histological examination showed a parathyroid nodular hyperplasia. During the follow-up, she suffered from persistent hyperparathyroidism due to a left parathyroid hyperplasia. Thus she was treated with RFA. Blood tests after the procedure showed the remission of the disease 7 months post-treatment.

CONCLUSION

A minimally invasive technique for PHPT may represent a valid alternative to surgery, especially in patients with an elevated surgery-related risk. More studies are necessary to investigate the benefit of RFA as a first-line treatment in PHPT.

Severe secondary hyperparathyroidism in a chronic kidney disease patient treated with Radiofrequency ablation: One case report

End-stage renal disease (ESRD) is a global health problem with a high incidence (1) and a steadily increasing prevalence (2). Secondary hyperparathyroidism (SHPT) is a common and serious complication of chronic renal failure (CRF) in dialysis patients (3). It is mainly manifested as parathyroid hyperplasia caused by abnormal calcium and phosphorus metabolism and active vitamin D resistance, resulting in excessive secretion of parathyroid hormone (PTH), which leads to complications such as bone deformity, osteoarthralgia, pruritus, ectopic calcification, and cardiovascular calcification in CKD patients, significantly reducing the quality of life in CKD patients (4, 5). In patients with chronic kidney disease, secondary parathyroid gland hyperplasia needs to be treated as early as possible (6). Currently, there are a variety of treatment options, including vitamin D receptor agonists, xenacax hydrochloride, parathyroidectomy and ablation techniques, etc. (7, 8). Medical treatment is the main choice among these treatments, but it is invalid in patients with severe hyperparathyroidism. So, parathyroidectomy is suggested to do in those patients (9). However, many dialysis patients who have severe cardiopulmonary dysfunction cannot tolerate the trauma caused by surgery as the concept of minimally invasive surgery has been gradually introduced into all fields of surgery and medical treatment. Traditional surgery is no longer the only option. Radiofrequency ablation has been widely applied due to its advantages of less trauma, simple operation, and good repeatability. It has been reported to achieve good effects in treating secondary hyperparathyroidism patients (8). This case reports that one severe secondary hyperparathyroidism patient gets good therapeutic results from parathyroid radiofrequency ablation.

Radiofrequency ablation of parathyroid adenomas causing primary hyperparathyroidism: A report of 27 patients

PURPOSE

To study treatment outcome of parathyroid adenomas using ultrasound-guided radiofrequency ablation.

METHODS

Twenty-seven patients with a single adenoma of the parathyroid gland were included in the study. Using color Doppler ultrasonography, the lesion and its characteristics were determined, and dextrose was injected to dissect the gland from the surrounding structures. The ablation process was done with 6-12 watts of power.

RESULTS

No complications were seen in any of the subjects. A significant reduction was seen in serum parathyroid hormone (PTH) and calcium levels after treatment. PTH levels showed a median decrease of 13.8%, and a median decrease of 8.2% was seen in serum calcium levels (p < 0.001). Phosphorus levels did not change significantly after treatment. In 1-month follow-up of patients, the lesion size had decreased considerably. In long-term follow-up, 11 of 20 patients having subsequent imaging had indistinguishable lesions.

CONCLUSION

Our results showed that RFA of parathyroid adenomas caused a significant reduction in biomedical indicators of disease and resulted in a significant reduction or disappearance of the lesion in the majority of the patients while having no considerable complications.

Ultrasound-guided thermal ablation for hyperparathyroidism: current status and prospects

BACKGROUND

Hyperparathyroidism (HPT) is classified into primary HPT (PHPT), secondary HPT (SHPT), tertiary HPT (THPT), and pseudohyperparathyroidism. Parathyroid surgery is generally reserved for patients with symptomatic PHPT and asymptomatic patients who meet the surgical guideline criteria. However, the risk of complications and mortality after parathyroid gland surgery increases with increasing patient age.

AIM

This study aimed to review existing research on laser ablation, radiofrequency ablation, microwave ablation, and high-intensity focused ultrasound in the treatment of HPT and analyze its application prospects.

CONCLUSIONS

Thermal ablation is a good alternative treatment for patients with parathyroid hyperplasia who do not meet the criteria or decline surgery. Being a type of minimally invasive treatment, ultrasound-guided thermal ablation has the advantages of easy operation, rapid recovery, and reusability and is used widely.

Microwave ablation as an efficient therapy for primary hyperparathyroidism: Efficacy and predictors of treatment success

BACKGROUND

Microwave ablation (MWA) has great potential for the treatment of primary hyperparathyroidism, but as predictors and therapeutic efficiency have not been fully clarified, further investigations are required.

AIM

The purpose of this study was to explore the predictors of MWA efficacy in patients with primary hyperparathyroidism (PHPT) induced by parathyroid adenoma.

METHODS

The study included patients with PHPT treated with MWA separated into two groups as response and no response group, according to the efficacy of the treatment. The two groups were compared with respect of possible predictors, such as age, gender, parathyroid adenoma volume, baseline levels of calcium (Ca), phosphorous (P), alkaline phosphate (ALP) and vitamin D, localisation of parathyroid adenoma, and instrumental parameters such as microwave ablation time and power. The statistical significance of possible predictors of MWA efficacy was investigated by using logistic regression analysis.

RESULTS

Evaluation was made of 32 patients in respect of analysing predictors of MWA efficacy. In the comparison of the values of the response and no response groups, only baseline Ca level was determined to be a potential predictor of the efficacy of MWA (P < .05). Further logistic regression results showed the baseline Ca level to be insignificant for the construction of a mathematical model to predict the efficacy of MWA (P = .071). The clinical success rate was 87.5%. Compared with pre-MWA, the serum PTH, calcium, phosphorus and ALP levels were significantly improved at 6 months post-MWA (PTH, 99 (86-154) ng/L vs 50 (46-58) ng/L; calcium, 2.94 (2.81-2.98) mmol/L vs 2.38 (2.28-2.50) mmol/L; phosphorus, 0.87 (0.82-1.01) mmol/L vs 1.16 (1.0-1.3) mmol/L; ALP, 82 (73-98) U/L vs 69 (54-84) U/L, respectively; all, P < .01.

CONCLUSIONS

Although no predictor of treatment success could be determined, MWA might be an effective treatment in patients with PHPT.

Ultrasound-guided microwave ablation for secondary hyperparathyroidism: a systematic review and meta-analysis

OBJECTIVES

Microwave ablation (MWA) is used for the treatment of severe secondary hyperparathyroidism (SHPT), but its efficacy and safety still remained unclear. This study aimed to investigate the efficacy and safety of ultrasound (US)-guided MWA in patients with SHPT.

METHODS

The PubMed, Cochrane library, Embase, China national knowledge infrastructure (CNKI) and Wanfang databases were searched to identify published studies that evaluated the efficacy and safety of US-guided MWA in patients with SHPT. The primary outcomes were parathyroid hormone (PTH), serum calcium and phosphorus levels.

RESULTS

A total of 26 studies with 932 patients were identified. The PTH levels showed significant reduction at 1 month [weighted mean difference (WMD) = 945.33, 95% CI: 797.15∼1093.52] and 6 months (WMD = 1,151.91, 95% CI: 990.93∼1312.89) after MWA of SHPT patients. The serum calcium (WMD = 0.39, 95% CI: 0.30 ∼ 0.48) and phosphorus levels (WMD = 0.64, 95% CI: 0.43 ∼ 0.85) showed significant reduction at 6 months after MWA of SHPT patients. The most common complications observed were hypocalcemia (35.2%) and transient hoarseness (9.2%). No other major complications or death occurred in our study patients.

CONCLUSION

These findings suggest MWA as a safe and effective minimally invasive technique for the management of SHPT. PTH, calcium, and phosphorus levels were significantly reduced at 1 and 6 months after MWA.

Effectiveness and Safety of Thermal Ablation in the Treatment of Primary Hyperparathyroidism: A Multicenter Study

CONTEXT

Ultrasound (US)-guided thermal ablation has generated recent interest as minimally invasive treatments of primary hyperparathyroidism (pHPT). But definitive evidence for the efficacy of thermal ablation in treating pHPT is not well characterized.

OBJECTIVE

This work aims to evaluate the effectiveness and safety of thermal ablation for pHPT.

METHODS

From January 2015 to March 2020, data pertaining to patients who received thermal ablation for pHPT at 4 centers were retrospectively analyzed. The median follow-up duration was 18.1 months (interquartile range, 6.5-42.2 months). A cure referred to the reestablishment of normal values of serum calcium and intact parathyroid hormone throughout the entire follow-up period, at least more than 6 months. The technical success, effectiveness, and safety of treatment were analyzed.

RESULTS

A total of 119 patients (mean age, 57.2 ± 16.3 years; 81 female) with 134 parathyroid nodules were enrolled. The mean maximum diameter of the parathyroid glands was 1.6 ± 0.9 cm. Ninety-six patients underwent microwave ablation (MWA), and 23 patients underwent radiofrequency ablation (RFA). The technical success rate was 98.3% and the cure rate was 89.9%. Significant differences were found in the maximum diameter between the cured patients and the patients who did not undergo ablation of the target lesions. Except for cases with pHPT nodules less than 0.6 cm in diameter, the cure rate was 95%. There were no difference in cure rates at 6 months between the MWA and RFA groups (MWA vs RFA, 90.6% vs 87.0%; χ 2 = 0.275, P = .699). The volume reduction rate of the ablation zone was 94.6% at 12 months. The complication rate was 6.7% (8/119). With the exception of one patient with persistent voice impairment, other symptoms spontaneously resolved within 6 months.

CONCLUSION

Thermal ablation is effective and safe for pHPT.

Microwave ablation versus radiofrequency ablation for primary hyperparathyroidism: a multicenter retrospective study

OBJECTIVE

To compare the clinical outcomes of microwave ablation (MWA) and radiofrequency ablation (RFA) in the treatment of primary hyperparathyroidism (pHPT).

METHOD

This retrospective study included 104 pHPT patients treated by MWA or RFA between January 2015 and March 2020 in four centers. The clinical outcomes including effectiveness and complications were compared between the two groups. Ablation cure was defined as the reestablishment of normal values of serum calcium and intact parathyroid hormone (iPTH) at least more than 6 months. Clinical cure was defined as the reestablishment of normal values of serum calcium and iPTH throughout the entire follow-up period.

RESULTS

A total of 77 patients underwent MWA (mean age, 55.5 ± 16.4 years) and 27 underwent RFA (mean age, 58.9 ± 15.6 years). During the follow-up (median, 18.7 months in the MWA group; 12 months in the RFA group), no difference was observed between ablation cure rates (88.3% vs. 88.9%, p = 1.000), clinical cure rates (87.0% vs. 82.3%, p = .880), recurrent pHPT (5.2% vs. 3.7%, p = .447), persistent pHPT (11.7% vs. 11.1%, p = 1.000) and complication rate (9.1% vs. 3.7%, p = .677). A maximum diameter less than 0.7 cm was an independent prognostic factor of uncured pHPT in ablation (hazard ratio, 0.1; 95% confidence interval: 0.02, 0.54; p = .007). Major complication - voice change encountered in five patients (6.5%) in the MWA group and in one patient (3.7%) in the RFA group.

CONCLUSION

Both RFA and MWA are safe and effective techniques for patients with pHPT, with comparable clinical outcomes.

Ultrasound-guided radiofrequency ablation for the treatment of primary hyperparathyroidism: An efficacy and safety study

OBJECTIVE

To evaluate the efficacy and safety of radiofrequency ablation (RFA) for the treatment of primary hyperparathyroidism (pHPT).

METHODS

25 patients who were treated with RFA for pHPT from September 2015 to January 2020 were enrolled in our study. The serum intact parathyroid hormone (iPTH), calcium and phosphate levels were tested within 1 week before RFA and at 1 day, 1 month, 3months, 6months and 12months after ablation. The ablation areas were evaluated by US at 1, 3, 6 and 12 months after RFA. Postoperative complications including voice hoarseness, hematoma, postoperative pain, incision infections, hypoparathyroidism and hypocalcemia were recorded.

RESULTS

A total of 25 pHPT patients (53.9 ± 10.9 years, 22 women and 3 men) with 29 enlarged parathyroid glands were treated by RFA. 22 of them were treated in one session and the other three were treated in two sessions. Serum iPTH and calcium levels decreased significantly at 1 day after RFA (all P < 0.05). 21 patients had normal levels of serum iPTH and calcium after RFA, with a cure rate of 84%. 26 treated parathyroid glands exhibited a volume reduction rate greater than 70% at the 12 months follow-up. There were only some minor complications, including four postoperative pain (4/25, 16%) and one mild postoperative transient hypocalcemia (1/25, 4%).

CONCLUSIONS

US-guided RFA is an effective and safe technique for the treatment of carefully selected patients with pHPT. Larger sample size and longer follow-up are still need to further confirm its clinical value.

Two-year changes of biochemical profiles and bone mineral density after percutaneous ultrasound-guided microwave ablation for primary hyperparathyroidism

PURPOSE

To investigate the changes of the serum parathyroid hormone (PTH) and calcium level, as well as bone mineral density (BMD), after percutaneous ultrasound-guided microwave ablation (MWA) for primary hyperparathyroidism (pHPT) caused by single hyperfunctional nodule.

METHODS

The study enrolled 20 patients with a total of 20 nodules of MWA treatment to pHPT in one session. The normalization rate of the serum PTH and calcium was evaluated at every 6 months during 2-year follow-up after MWA. The bone mineral density (BMD) at lumbar spine and femoral neck were also compared before and after the procedure.

RESULTS

The normalization rate of both PTH and serum calcium at 6-, 12-, 24-month follow-up was 66.6%, 80.0%, and 62.5%, respectively. Though the normalization rate of serum calcium level at 6-, 12-, and 24-month visit after MWA was 100%. The BMD increased 12, 24 months after MWA at lumbar spine (1.022 ± 0.155, 1.057 ± 0.151 vs 0.965 ± 0.145 g/cm², p < 0.01) and femoral neck at 2-year assessment (0.819 ± 0.094 vs 0.771 ± 0.102 g/cm², p = 0.015). Seven nodules disappeared in 20 nodules (35.0%), average ablation time was 122.29 ± 107.54 s (34-460 s). Six patients encountered voice change during the procedure, one participant was confirmed recurrent laryngeal injuries but recovered within 2 months.

CONCLUSIONS

Percutaneous ultrasound-guided microwave ablation results in improvement of biochemical profiles and bone mineral density in subjects with single hyperfunctional parathyroid nodule. However, the long-term efficacy of the MWA remains to be verified.

Radiofrequency Ablation of Parathyroid Adenoma: A Novel Treatment Option for Primary Hyperparathyroidism

Objective

To present radiofrequency ablation (RFA) of parathyroid adenomas as a safe and effective management strategy for primary hyperparathyroidism in patients who are not eligible for surgery or those who do not want surgery.

Methods

The diagnosis of primary hyperparathyroidism was confirmed by laboratory investigations. A bone density scan showed osteoporosis, which was an indication for the surgical treatment of primary hyperparathyroidism. Ultrasonography of the neck was done to localize the parathyroid adenoma, after which RFA was performed to shrink the adenoma. Laboratory investigations were performed 10 days, 6 months, and 12 months after the procedure. A literature review was also conducted, and other reports of primary hyperparathyroidism cases treated with RFA were identified.

Results

Biochemical cure of primary hyperparathyroidism was achieved by normalization of calcium levels, resolution of symptoms, elimination of complications, and decrease in the volume of the parathyroid adenoma.

Conclusion

RFA of parathyroid adenomas is a viable alternative to parathyroidectomy in patients who do not meet the criteria for surgery or do not wish to undergo surgery.

Radiofrequency Ablation of Parathyroid Adenomas: Safety and Efficacy in a Study of 10 Patients

PURPOSE

To evaluate safety and effectiveness of ultrasound-guided percutaneous radiofrequency ablation of parathyroid adenoma in surgically unfit patients with hypercalcemia because of hyperparathyroidism.

MATERIALS AND METHODS

A retrospective review of hospital records from Jan 2012 to Dec 2018 revealed 10 patients, who had undergone ablation for solitary parathyroid adenoma. All 10 patients suffered from hyperparathyroidism because of parathyroid adenoma, resulting in hypercalcemia. These patients were surgically unfit because of comorbidities. Pre-ablation serum calcium and serum parathormone levels were measured and compared with the levels after the ablation.

RESULTS

Mean serum calcium level decreased significantly from 2.81 ± 0.17 mmol/L pre-ablation to 2.42 ± 0.17 mmol/L 72 h after ablation and parathyroid hormone levels became normal in all patients within 7 days. Seven patients remained normo-calcaemic at 6 months follow-up with no signs and symptoms of hyperparathyroidism. One patient with pancreatitis died after 15 days because of pre-existing multi-organ failure. Two patients were lost to follow-up before 6 months.

CONCLUSION

Radiofrequency ablation of parathyroid adenoma is a safe and effective alternate treatment method for symptomatic hypercalcemia in surgically unfit patients suffering from primary hyperparathyroidism because of parathyroid adenoma.

Clinical Study on Safety and Efficacy of Microwave Ablation for Primary Hyperparathyroidism

Objective

To evaluate the safety, feasibility, and efficacy of microwave ablation (MWA) for the treatment of primary hyperparathyroidism (PHPT).

Materials and Methods

This study enrolled 67 PHPT patients (22 men, 45 women; mean age, 56.0 ± 16.3 years; range, 18–83 years) from January 2015 to December 2018. The laboratory data, including the serum intact parathyroid hormone (iPTH), calcium, phosphorus, and alkaline phosphatase (ALP) levels, were evaluated before MWA and again 2 hours, 1 day, 7 days, 1 month, 3 months, 6 months, 12 months, 18 months, and 24 months after.

Results

Complete ablation was achieved with all 72 hyperplastic parathyroid glands found on the 67 patients enrolled, 64 of whom were treated in one session and 3 were treated over two sessions. The technical success rate was 100%. The median follow-up time was 13.6 months (range, 10.0–31.1 months). The clinical success rate was 89.4%. The volume reduction rate was 79.4% at 6 months. Compared to pre-MWA, the serum iPTH, calcium, phosphorus, and ALP levels had significantly improved 6 months post-MWA (iPTH, 157.3 pg/mL vs. 39.2 pg/mL; calcium, 2.75 ± 0.25 mmol/L vs. 2.34 ± 0.15 mmol/L; phosphorus, 0.86 ± 0.20 mmol/L vs. 1.12 ± 0.22 mmol/L; ALP, 79 U/L vs. 54 U/L, respectively; all, p < 0.01). Hoarseness was a major complication in 4 patients (6.0%), but it improved spontaneously within 2–3 months.

Conclusion

MWA is safe, feasible, and effective for the treatment of PHPT.

Minimally Invasive Treatment for Benign Parathyroid Lesions: Treatment Efficacy and Safety Based on Nodule Characteristics

OBJECTIVE

This study aimed to evaluate the efficacy and safety of ultrasound (US)-guided minimally invasive treatment in patients with parathyroid lesions.

MATERIALS AND METHODS

This study included 27 patients who had undergone US-guided radiofrequency ablation (RFA) or ethanol ablation (EA) for parathyroid lesions between January 2010 and 2018. RFA was performed in 19 patients with primary hyperparathyroidism (PHPT, n = 11) or secondary hyperparathyroidism (SHPT, n = 8), and EA was performed in eight patients with symptomatic nonfunctioning parathyroid cysts (SNPCs). Nodule size, volume, serum parathyroid hormone (PTH) and calcium levels were recorded before and after treatment. Complications were evaluated during and after treatment.

RESULTS

In patients with PHPT, significant reductions in size and volume were noted after RFA at 6- and 12-month follow-up (all, p < 0.05). Seven nodules nearly completely disappeared (residual volume < 0.1 mL); serum PTH and calcium levels were reduced to normal ranges (7/11, 63.6%). Four patients experienced partial reductions of serum PTH and calcium levels (4/11, 36.4%). In patients with SHPT, three experienced therapeutic response of serum PTH (3/8, 37.5%), while five showed persistent hyperparathyroidism (5/8, 62.5%) within 6 months after RFA. In patients with SNPCs, EA resulted in significant reductions in cyst size and volume (all, p < 0.05) at the last follow-up. A total of four complications (two transient hypocalcemia [RFA], one permanent [RFA], and one transient [EA] hoarseness) were observed.

CONCLUSION

Minimally invasive treatments, such as RFA and EA, may serve as therapeutic alternatives for patients with PHPT or SNPCs; they may have limited usefulness in patients with SHPT.

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

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.

Microwave ablation vs. parathyroidectomy for secondary hyperparathyroidism in maintenance hemodialysis patients

INTRODUCTION

Secondary hyperparathyroidism (SHPT) is a serious and common problem in patients undergoing maintenance hemodialysis. Minimally invasive microwave ablation (MWA) has been used to treat SHPT and shows some advantages. However, its efficacy is still undefined. The primary purpose of this study was to determine the efficacy and safety of MWA compared to total parathyroidectomy plus forearm autotransplantation.

METHODS

The SHPT patients who were undergoing maintenance hemodialysis (follow-up for 6 to 24 months after treatments) were divided into a MWA group (n = 33) and a parathyroidectomy group (n = 48). The efficacy (serum intact parathyroid hormone [iPTH], calcium, and phosphorus levels) and safety (hoarseness, hypocalcaemia, and persistently low iPTH) were compared between the two groups. Additionally, the study explored potential predictors of response to MWA by a logistic regression analysis.

FINDINGS

There were no significant differences in baseline characteristics between the two groups. The rates of achieving the recommended goal for iPTH were significantly higher in the MWA group than that in the parathyroidectomy group at all follow-up times: 57.58% vs. 12.50% at one-day (P < 0.001), 45.45% vs. 16.67% at 1-week (P = 0.005), 57.58% vs. 16.67% at 2-week (P < 0.001), 57.58% vs. 22.92% at 1-month (P = 0.002), and 69.70% vs. 35.42% at 3-month (P = 0.002), 76.47% vs. 28.57% at 6-month (P = 0.005), 87.50% vs. 47.37% at 12-month (P = 0.008), and 81.82% vs. 52.63% at 24-month (P = 0.015), respectively. However, there were no significant differences for phosphorus or calcium at any of the follow-up times (P > 0.05). The persistently low iPTH was more in the parathyroidectomy group (64.6%) than that in the MWA group (0%) (P < 0.001), but there was no significant difference in hoarseness or hypocalcaemia (P > 0.05). Baseline levels of iPTH (P = 0.021) and patient age (P = 0.011) were determined as predictors by univariate logistic regression analysis.

CONCLUSION

The MWA could be an alternative to parathyroidectomy for SHPT but its eventual superiority has to be demonstrated by a proper study.

Radiofrequency Ablation Followed by Percutaneous Ethanol Ablation Leading to Long-Term Remission of Hyperparathyroidism

A 30-year-old male with cerebral palsy and motor impairment presented with right femur fracture. He had gradually worsening mobility and contractures of all extremities for the preceding 5 years. Evaluation showed multiple vertebral and femoral fractures, severe osteoporosis, a large parathyroid adenoma, and parathormone (PTH) exceeding 2500 pg/mL. Because of poor general health and high anesthetic risk, parathyroidectomy was deemed impractical. Ultrasound-guided radiofrequency ablation (RFA) helped achieve 50% size reduction and PTH levels with better control of hypercalcemia. Later, as calcium and PTH remained elevated, percutaneous ethanol ablation was performed with resultant normalization of PTH and substantial symptomatic improvement. Two years later, he still remains normocalcaemic with normal PTH levels. We propose that RFA and percutaneous ethanol ablation be considered as effective short-term options for surgically difficult cases, which could even help achieve long-term remission. Although not previously reported, our case illustrates that both RFA and percutaneous ethanol ablation could be safely performed successively achieving long-term remission.

Efficacy and safety of ultrasound-guided radiofrequency ablation of hyperplastic parathyroid gland for secondary hyperparathyroidism associated with chronic kidney disease

BACKGROUND

The purpose of this study was to determine if ultrasound-guided radiofrequency ablation (RFA) of hyperplastic parathyroid glands could be used to treat secondary hyperparathyroidism (HPT) in patients with chronic kidney disease.

METHODS

RFA of the hyperplastic parathyroid glands was performed in 34 patients with secondary HPT. Intact parathyroid hormone (iPTH), calcium, and phosphorus were measured. The outcome was based on the ablation extent (ie, 4, 3, and 1-2 glands).

RESULTS

The iPTH, calcium, and phosphorus levels decreased in all groups after RFA. One year after ablation, these parameters remained significantly lower in the 4-gland ablation group compared with the 3-gland and 1 to 2-gland groups. The same tendency was observed for the symptom score. The iPTH levels of <272 pg/mL on the day after ablation was the best predictor for maintaining parathyroid hormone (PTH) levels in a reasonable range 1 year after ablation.

CONCLUSIONS

RFA of hyperplastic parathyroid glands for treating secondary HPT is feasible in selected patients. © 2016 Wiley Periodicals, Inc. Head Neck 39: 564-571, 2017.

A Review of Therapeutic Ablation Modalities

Understanding basic science and technical aspects is essential for scientists and engineers to develop and enhance ablative modalities, and for clinicians to effectively apply therapeutic ablative techniques. An overview of ablative modalities, anatomical locations, and indications for which ablations are performed is presented. Specifically, basic concepts, parameter selection, and underlying biophysics of tissue injury of five currently used therapeutic ablative modalities are reviewed: radiofrequency ablation (RFA), cryoablation (CRA), microwave ablation (MWA), high-intensity focused ultrasound (HIFU), and chemical ablation (CHA) (ablative agents: acetic acid, ethanol, hypertonic sodium chloride, and urea). Each ablative modality could be refined for expanding applications, either independently or in combination, for future therapeutic use.

Percutaneous Ultrasound-Guided Laser Ablation with Contrast-Enhanced Ultrasonography for Hyperfunctioning Parathyroid Adenoma: A Preliminary Case Series

The study was to evaluate the safety and effectiveness of ultrasound-guided percutaneous laser ablation (pLA) as a nonsurgical treatment for primary parathyroid adenoma. Surgery was contraindicated in, or refused by, the included patients. No lesion enhancement on contrast-enhanced ultrasound immediately after pLA was considered "complete ablation." Nodule size, serum calcium, and parathyroid hormone level were compared before and after pLA. Complete ablation was achieved in all 21 patients with 1 (n = 20) or 2 (n = 1) sessions. Nodule volume decreased from 0.93 ± 0.58 mL at baseline to 0.53 ± 0.38 and 0.48 ± 0.34 mL at 6 and 12 months after pLA (P < 0.05). At 1 day, 6 months, and 12 months after pLA, serum PTH decreased from 15.23 ± 3.00 pmol/L at baseline to 7.41 ± 2.79, 6.95 ± 1.78, and 6.90 ± 1.46 pmol/L, serum calcium decreased from 3.77 ± 0.77 mmol/L at baseline to 2.50 ± 0.72, 2.41 ± 0.37, and 2.28 ± 0.26 mmol/L, respectively (P < 0.05). At 12 months, treatment success (normalization of PTH and serum calcium) was achieved in 81%. No serious complications were observed. Ultrasound-guided pLA with contrast-enhanced ultrasound is a viable alternative to surgery for primary parathyroid adenoma.