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

[Local ablative procedures for treatment of thyroid nodules]

Thyroid nodules are very frequent in the iodine deficiency regions of central Europe and some of the affected patients are referred for definitive treatment, such as surgery and radioiodine treatment. In recent years nonsurgical and non-radioiodine techniques have been introduced to treat thyroid gland pathologies. These techniques include the probe-based techniques of radiofrequency, microwave and laser application. The only noninvasive technique is high-intensity focused ultrasound. All mentioned techniques have the goal to reduce the volume of the thyroid nodule by application of energy/heat. The knowledge of all techniques and their advantages and risks is necessary to help physicians and patients in making decisions for the appropriate method of treatment of thyroid nodules.

The Role of Laser and Microwave in Treatment of Endocrine Disorders: A Systematic Review

Introduction: The treatment of endocrine problems like thyroid disease, diabetes mellitus (DM), and polycystic ovary syndrome (PCOS) faces significant challenges so that medical professionals worldwide try to find a new therapeutic approach. However, along with common treatments which include medications, hormone replacement therapy, and surgery; there is a growing interest in alternative therapies like laser therapy, which offers a non-invasive and unique technique for treating endocrine disorders alone or in combination with traditional methods. The main goal of this review was to do a systematic review on the role of the laser and Microwave in the treatment endocrine disorders. Methods: In the present systematic review, the most important databases, including PubMed, Scopus and Google Scholar, were searched for the studies examining the effect of lasers on the treatment of endocrine problems by using appropriate keywords and specific strategies from 1995 to 2023. All the studies that were not about lasers and endocrine were excluded. Results: Based on 51 reviewed studies, lasers and radiofrequency ablation such as RFA are effective in the treatment of thyroid diseases, hyperparathyroidism, pancreatic disorders, and sexual dysfunctions. Laser-induced interstitial thermal therapy (LITT) and microwave ablation (MWA) are genuine minimally invasive methods for the treatment of benign nodules, adenomas, and tumor ablation including pancreatic carcinomas and adrenal tumors. Intravenous laser blood irradiation (ILBI) which uses red, UV, and blue light could be effective in treating various metabolic disorders, such as DM. Conclusion: Laser as a cutting-edge and minimally invasive approach could treat various endocrine disorders. It has a great potential to treat and regulate hormonal imbalances, decrease inflammation, and relieve symptoms of various ailments, such as endocrine disorders.

Radiofrequency Ablation of Parathyroid Adenoma: Results of a Retrospective Analysis of 60 Patients

PURPOSE

To present the effectiveness and safety of radiofrequency ablation (RFA) in parathyroid adenoma (PTA).

MATERIALS AND METHODS

In this retrospective study, 60 patients with a single PTA were evaluated for changes in biochemical and ultrasonographic features up to 6 months after RFA of the lesion. Adenomas were ablated with an alternative technique so called "Nik jet dissection" which incorporates full hydrodissection and polar artery coagulation. Complications as well as the variations in biochemical data and nodule volumes were analyzed between baseline measurements and at each follow-up interval data (first day, 1, 3, and 6 months after ablation) were analyzed.

RESULTS

A significant reduction in serum intact parathyroid hormone and calcium levels was observed 6 months after ablation, with a mean difference of - 83.4 ± 104.1 pg/mL, p < 0.001, and - 0.29 ± 0.22 mmol/L, p < 0.001, respectively. Serum phosphorus levels increased significantly with a mean difference of 0.09 ± 0.19 mmol/L, p = 0.040 at the end of the follow up. We observed a significant volume reduction rate of parathyroid adenomas with 89 ± 20.8 percent, p < 0.001. Also, 51% of adenomas disappeared at the end of the follow up. In this study, two cases of hematoma and one case of transient hoarseness (grade 1 of the CIRSE classification) were encountered.

CONCLUSION

Our study showed that RFA with the alternative technique, called "Nik jet dissection" is a safe and effective modality in management of PTA. Therefore, we suggest expanding the indications for RFA in PTA management, especially when surgery is not feasible.

LEVEL OF EVIDENCE

Level 3, Local non-random sample.

Future Directions in the Treatment of Thyroid and Parathyroid Disease

The surgical management of thyroid and parathyroid disease has evolved considerably since the era of Theodor Kocher. We review the current trends in thyroid and parathyroid surgery concerning robotic surgery for remote access, the use of parathyroid autofluorescence detection technology to aid in the prevention of hypocalcemia as well as the use of thermal ablation to target thyroid nodules in a minimally invasive way. We also discuss how artificial intelligence is being used to improve the workflow and diagnostics preoperatively as well as for intraoperative decision-making. We also discuss potential areas where future research may enhance outcomes.

Radiofrequency ablation as a treatment modality for primary hyperparathyroidism: a systematic literature review

Background

Primary hyperparathyroidism (pHPT) is an endocrine disorder typically characterized by elevated serum calcium and elevated parathyroid hormone (PTH). While parathyroidectomy is the standard treatment, non-operative intervention such as radiofrequency ablation (RFA) has been adopted as an alternative for the management of pHPT, as it has been utilized in other endocrine glands such as thyroid and adrenal. In this literature review, we aim to evaluate the current practice of RFA for pHPT.

Methods

A systematic literature search using PubMed, Web of Science, and Embase through June 2022 was conducted. Studies included in the review consisted of patient cohorts who had an unequivocal diagnosis of pHPT and underwent the treatment of pHPT with RFA. When more than one study was published from a similar cohort of patients, only the study with the most number of patients was considered. Studies included were assessed for bias using the critical appraisal instruments from the Joanna Briggs Institute (JBI) System.

Results

A total of 14 studies describing 167 parathyroid glands treated in 163 patients were reviewed. The overall cure rate was 91.2%, with 5 patients undergoing more than one ablation. The most common adverse effect encountered was temporary dysphonia. Incomplete ablation and missed multiglandular disease were the most common reasons for RFA treatment failure.

Conclusions

RFA may be an effective and safe alternative to parathyroidectomy in select patients with a well-localized, well-located parathyroid adenoma. Additional long-term data are needed to refine its role in the pHPT treatment algorithm.

Treating intra-thyroid parathyroid adenoma by radiofrequency is a valuable alternative to hemithyroidectomy

BACKGROUND

Parathyroid adenoma (PA) is the most common cause of primary hyperparathyroidism (PHPT). One infrequent scenario (0.7%-6%) is represented by intra-thyroid PA (I-PA), an ectopic variant of the parathyroid gland included in the thyroid parenchyma. Radiofrequency (RF) of I-PA seems to be an excellent alternative to hemithyroidectomy for these patients. The present study aimed to report three cases of PHPT and I-PA treated with RF at two institutions.

MATERIALS AND METHODS

These two institutions share guidelines for thyroid RF. At both institutions, cases with surgical indication and difficult PA localization are discussed during thyroid multidisciplinary meetings involving all disciplines involved in managing these cases. RF was performed using a Viva RF System generator (STARMED). Ultrasound contrast evaluation was performed using a SonoVue (Bracco). All patients were followed-up by an expert endocrinologist.

RESULTS

Three cases had indications for treating I-PA. All patients were proposed to undergo RF rather than hemithyroidectomy, and accepted this option. RF of I-PA was performed with a power of 30-50 W and delivering a total between 0.02 and 0.69 Kcal. The active treatment lasted just more than 1 min. Post-treatment follow-up revealed PTH and calcium normalization.

CONCLUSION

This study showed highly encouraging results in favor of treating I-PA with RF.

Effectiveness and safety of the radiofrequency ablation of single hyperfunctioning parathyroid lesions suggestive of adenomas in primary hyperparathyroidism

INTRODUCTION

Radiofrequency ablation (RFA) has emerged as a minimally invasive approach to single parathyroid adenoma in primary hyperparathyroidism; however, there is limited evidence on its effectiveness.

OBJECTIVE

To evaluate the effectiveness and safety of RFA to treat hyper-functioning parathyroid lesions suggestive of adenomas.

MATERIAL AND METHODS

A prospective study was conducted in consecutive patients with primary hyperparathyroidism treated with RFA for single parathyroid lesions in our reference center between November 2017 and June 2021. Pre-treatment (baseline) and follow-up analytical data were gathered on total protein-adjusted calcium, parathyroid hormone [PTH], phosphorus, and 24-h urine calcium. Effectiveness was defined as complete response (normal calcium and PTH), partial response (reduced but not normalized PTH with normal serum calcium), or disease persistence (elevated calcium and PTH). SPSS 15.0 was used for statistical analysis.

RESULTS

Four of thirty-three enrolled patients were lost to the follow-up. The final sample comprised 29 patients (22 females) with mean age of 60.93 ± 13.28 years followed up for a mean of 16.29 ± 7.23 months. Complete response was observed in 48.27%, partial response in 37.93%, and hyperparathyroidism persistence in 13.79%. Serum calcium and PTH levels were significantly lower at 1 and 2 years of post-treatment than at baseline. Adverse effects were mild, with two cases of dysphonia (self-limited in one patient) and no cases of hypocalcaemia or hypoparathyroidism.

CONCLUSION

RFA may be a safe and effective technique to treat hyper-functioning parathyroid lesions in selected patients.

Clinical and Economic Evaluation of Ultrasound-Guided Radiofrequency Ablation vs. Parathyroidectomy for Patients with Primary Hyperparathyroidism: A Cohort Study

RATIONALE AND OBJECTIVES

To compare the clinical and economic effects of ultrasound (US)-guided radiofrequency ablation (RFA) with parathyroidectomy (PTX) for primary hyperparathyroidism (PHPT).

MATERIALS AND METHODS

From April 2014 to April 2021, 123 PHPT patients who received US-guided RFA or PTX were studied. Propensity score (PS) matching was used to balance the baseline data of the two groups. The rates of cure, recurrent and persistent PHPT, and complications were compared. A Chinese healthcare system perspective cost minimization analysis was conducted.

RESULTS

After PS matching, 37 patient pairs (1:1) were created for the two groups. Follow-up was 27.2 ± 10.6 months and 28.8 ± 16.1 months for the RFA and PTX groups, respectively. At the last follow-up, there was no evidence of differences regarding clinical cure rate between the two groups (RFA vs. PTX, 91.9% vs. 94.6%, p = 1.000). Recurrent PHPT did not develop in any patient. One patient in each group had persistent PHPT. The incidence of complications and side effects, except postoperative pain (RFA vs. PTX, 16.2% vs. 40.5%, p = 0.020), were no significant difference between the two groups (all, p > 0.05). The incremental cost was -$284.00; thus, RFA was more cost-effective. For patients with employee medical insurance or resident medical insurance, the incremental costs (RFA vs. PTX) were -$391.94 and -$49.43, respectively.

CONCLUSION

There were no significant differences in efficacy and safety between RFA and PTX. As the incremental cost for RFA compared with PTX was negative, RFA may be used as a more cost-effective nonsurgical treatment alternative for PHPT.

Efficacy and safety of radiofrequency ablation for primary and secondary hyperparathyroidism: a retrospective study

There is now growing interest in the use of Ultrasound-guided radiofrequency ablation (RFA) to treat hyperparathyroidism. But the efficacy and limitations of this treatment have not been described in sufficient detail. Assessing and contrasting the effectiveness and safety of RFA in treating primary hyperparathyroidism (PHPT) and secondary hyperparathyroidism (SHPT). This retrospective study included 57 HPT patients (48 for PHPT and 9 for SHPT) who underwent RFA between January 2017 and April 2021. The serum intact parathyroid hormone (iPTH) and calcium, hyperplastic parathyroid volume, volume reduction rate (VRR) before and after RFA, clinical success rate, symptoms, and complications were analyzed and compared. In SHPT group, bone pain (7/9, 77.8%), skin pruritus (4/9, 44.4%), and multiple hyperplastic parathyroid glands (4/9, 44.4%) were more common compared to the PHPT group. After 12 months of follow-up, the serum iPTH, calcium, and the volume of PHPT and SHPT groups had decreased by more than 60%, 10%, and 90%, respectively (P < 0.05). In the VRR, 13 glands of SHPT (72.2%) and 42 glands of PHPT (87.5%) had achieved the clinical success. In addition, the preoperative and postoperative serum iPTH were higher in the SHPT group than in the PHPT group (P < 0.05). In terms of the serum iPTH and calcium, the PHPT group had substantially higher rates of clinical success, with 42 patients (87.5%) and 46 patients (95.8%) meeting the criteria, respectively compared to 3 patients (33.3%) and 6 patients (66.7%) of SHPT group (P < 0.05). After RFA, the clinical symptoms improved in both groups. The overall incidence of complications (hoarseness and postoperative hematoma) of RFA in the two groups was 10.5% (6/57), and hoarseness (3/9, 33.3%) of SHPT group was more common than PHPT group. All the complications were resolved spontaneously within 12 months after symptomatic treatments. In the treatment of PHPT and SHPT, ultrasound-guided RFA is both successful and safe. PHPT patients have better results in restoring normal iPTH by RFA, and have no considerable difference with the SHPT patients in terms of serum calcium, the volume of the ablation area, and the VRR.

Radiofrequency ablation of an intrathyroidal parathyroid adenoma with intraoperative parathyroid hormone monitoring: a case report of a novel technique

Background

Primary hyperparathyroidism (PHPT) is classically treated by conventional parathyroidectomy, an open neck surgery. Radiofrequency ablation (RFA) has been shown as a safe minimally-invasive alternative to parathyroidectomy for the management of PHPT and has been shown to be effective in 60-90% of cases. Here, we present a patient successfully treated for persistent PHPT by RFA with simultaneous intraoperative parathyroid hormone (IOPTH) monitoring.

Case Description

A 51-year-old female with a past medical history of resistant hypertension, hyperlipidemia, and vitamin D deficiency presented to our endocrine surgery clinic with PHPT. Neck ultrasound (US) localized a 0.79 cm lesion suggestive of a parathyroid adenoma. Parathyroid exploration resulted in the excision of two masses. IOPTH levels dropped from 259.9 to 204.7 pg/mL. No ectopic parathyroid tissue was found. Three-month follow-up demonstrated elevated calcium levels, suggesting persistent disease. A repeat neck US one-year post operation localized a suspicious hypoechoic sub-centimeter thyroid nodule, which was subsequently determined to be an intrathyroidal parathyroid adenoma. The patient elected to proceed with RFA with IOPTH monitoring, citing concern for increased risk of redo open neck surgery. Operation pursued without complication and IOPTH levels dropped from 270 to 39.1 pg/mL. The patient's only three-day post-operative complaints, occasional numbness and tingling, were completely resolved by her three-month follow up. The patient had normal PTH and calcium levels at seven months post-operation visit and was without complaint.

Conclusions

To our best knowledge, this is the first reported case of RFA with IOPTH monitoring used to manage a parathyroid adenoma. Our work adds to the growing literature suggesting minimally-invasive techniques, such as RFA with IOPTH, as a potential management option for treating parathyroid adenomas.

Localization Strategy Prior to Radiofrequency Ablation for Primary and Secondary Hyperparathyroidism

Objective: Preoperative localization in patients with primary or secondary hyperparathyroidism before radiofrequency ablation (RFA) is crucial. There is currently a lack of consensus regarding imaging protocol. Evaluating the diagnostic performance of ultrasound, four-dimensional computed tomography (4D-CT), and technetium 99m-sestamibi single-photon-emission-computed tomography/computed tomography (SPECT/CT) is necessary for RFA of hyperparathyroidism. Methods: This retrospective study recruited patients with primary or secondary hyperparathyroidism who underwent ultrasound, 4D-CT, and SPECT/CT before RFA at a single institution. The sensitivity, accuracy, and receiver operating characteristic curve analysis were used to evaluate the diagnostic performance of the imaging modalities. Results: A total of 33 patients underwent RFA for hyperparathyroidism (8 patients with primary hyperparathyroidism, 25 patients with secondary hyperparathyroidism). Ultrasound had the highest sensitivity (0.953) and accuracy (0.943), while 4D-CT had higher sensitivity and accuracy than SPECT/CT (sensitivity/accuracy, 4D-CT vs. SPECT/CT: 0.929/0.920 vs. 0.741/0.716). Combined ultrasound with 4D-CT and the three combined modalities achieved equivalent, and the highest, diagnostic performance (sensitivity 1.000, accuracy 0.989). The lesion length and volume were important predictors of the diagnostic performance of 4D-CT and SPECT/CT (area under curve of length in 4D-CT/volume in 4D-CT/length in SPECT/volume in SPECT: 0.895/0.834/0.767/0.761). Conclusion: Combined ultrasound with 4D-CT provides optimal preoperative localization prior to RFA in patients with primary or secondary hyperparathyroidism. The length and volume of parathyroid lesions are determinative of the diagnostic performance of 4D-CT and SPECT/CT.

Combination Therapy of Ethanol Ablation and Radiofrequency Ablation to Treat Parathyroid Adenoma in a Case with Primary Hyperparathyroidism

Introduction: Ethanol ablation (EA) and radiofrequency ablation (RFA) are minimal invasive therapeutic modalities to treat primary hyperparathyroidism (PHPT). Case Presentation: A 77-year-old man presented a 3.5-cm parathyroid adenoma with mixed cystic and solid components. He was ineligible for parathyroidectomy because of his age and the surgical history of the coronary artery bypass graft. First, EA was performed to remove cystic component. After that, the volume of parathyroid adenoma was decreased (volume reduction rate: 94%); however, the level of serum parathyroid hormone (PTH) was persistently high (88 pg/mL). Subsequent RFA was performed to remove the remaining parathyroid adenoma. Further, it was completely disappeared on the following ultrasound examination, and PTH was normalized. The results during a 2-year follow-up confirmed clinical success, and no relevant complication was reported. Conclusion: The combination therapy of EA and subsequent RFA is safe and effective as an alternative therapeutic method to treat PHPT in patients ineligible for parathyroidectomy.

Efficacy and safety of radiofrequency ablation for primary and secondary hyperparathyroidism with or without previous parathyroidectomy: a retrospective study

INTRODUCTION

This study aimed to investigate and compare the therapeutic efficacy and safety of ultrasound-guided radiofrequency ablation (RFA), between primary hyperparathyroidism (PHPT) and secondary hyperparathyroidism (SHPT) patients, with or without previous parathyroidectomy (PTX).

SUBJECTS AND METHODS

A total of 21 patients (7 PHPT, 14 SHPT) underwent RFA for hyperparathyroidism (HPT) at Kaohsiung Chang Gung Memorial Hospital, Taiwan. Five of the 14 SHPT patients had previously received PTX. The laboratory data, volume change of each parathyroid nodule, symptomatic scores, and complications were analyzed and compared between all groups at 1 and 7 days, and at 1, 3, 6, and 12 months after RFA.

RESULTS

After RFA, the volume reduction ratio (VRR) for all patients at the last follow-up was 93.76%, and clinical symptoms significantly improved. At 12 months, all PHPT patients achieved successful treatment of intact PTH (iPTH). In SHPT patients, the mean iPTH value significantly decreased 1-day post-RFA, subsequently exhibiting a transient rebound which proceeded to decrease, with 57.1% reaching successful treatment standards. SHPT patients with PTX showed a lower complication score, shorter ablation time, higher iPTH baseline and outcomes, and lower VRR, compared to patients without PTX. The serum calcium level significantly decreased to normal range in 85.7% of all patients at 12 months. Severe hypocalcemia occurred in 23.8% at 1 week, and all were corrected with calcium supplements.

CONCLUSIONS

RFA demonstrates a therapeutic efficacy similar to PTX. It can thus be considered an effective alternative treatment for PHPT, SHPT, or post-PTX patients who are unsuitable for another PTX.

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.

Thyroid-dedicated internally-cooled wet electrode for benign thyroid nodules: experimental and clinical study

BACKGROUND

To assess the effects of radiofrequency ablation (RFA) using an internally-cooled wet (ICW) electrode in ex vivo bovine liver and evaluate the feasibility of the ICW electrode for benign thyroid nodules.

METHODS

We developed an 18-gauge ICW electrode with a microhole at the distal tip for tissue infusion of chilled (0 - 4 °C) isotonic saline (rate = 1.5 ml/min). RFA using ICW and IC electrodes were performed in bovine livers (40 pairs, 1-cm active tip, 50 W, 1-min). We compared the morphological characteristics of ablation zones and presence of carbonization. Twenty patients with benign thyroid nodules larger than 5 ml were prospectively enrolled in a clinical study and underwent ultrasound-guided RFA with ICW electrodes. Ultrasound examinations, laboratory data, and symptom and cosmetic scores were evaluated preprocedure and 1 and 6 months after the procedure.

RESULTS

In the ex vivo study, the ICW achieved significantly larger ablation zones than the IC (p<.001). In the clinical study, ICW electrodes were tolerable in all patients. At last follow-up, nodule volume had decreased from 15.6 ± 12.1 ml to 4.1 ± 4.3 ml (p<.001), and the mean volume reduction ratio (VRR) was 73.3 ± 13.7% at 6.0 months follow-up. Cosmetic and symptom scores were reduced from 3.52 ± 1.03 to 2.65 ± 0.88 and 3.10 ± 2.17 to 0.85 ± 0.99 (both p<.001), respectively. After RFA, thyroid function was well preserved in all patients, and mean thyroglobulin level decreased from 36.6 ± 52.1 ng/ml to 26.9 ± 62.2 ng/ml. One patient experienced a temporary voice change that recovered within a week.

CONCLUSIONS

We developed a thyroid-dedicated ICW electrode that we showed to be feasible and effective in patients with benign thyroid nodules.

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.

Advances in the treatment of secondary and tertiary hyperparathyroidism

Secondary hyperparathyroidism (SHPT) and tertiary hyperparathyroidism (THPT) are common and complicated clinical endocrine diseases. The parathyroid glands maintain endocrine homeostasis by secreting parathyroid hormone to regulate blood calcium levels. However, structural alterations to multiple organs and systems occur throughout the body due to hyperactivity disorder in SHPT and THPT. This not only decreases the patients' quality of life, but also affects mortality. Since current treatments for these diseases remains unclear, we aimed to develop a comprehensive review of advances in the treatment of SHPT and THPT according to the latest relevant researches.

Efficacy and Safety of Ultrasound-Guided Radiofrequency Ablation for Primary Hyperparathyroidism: A Prospective Study

Objective

To assess the efficacy and safety of ultrasound (US)-guided radiofrequency ablation (RFA) in patients with primary hyperparathyroidism (PHPT).

Materials and Methods

This prospective study enrolled 39 participants (14 male, 25 female; mean age, 59.5 ± 15.3 [range, 18–87] years) between September 1, 2018, and January 31, 2021. All participants had parathyroid lesions causing PHPT, proven biochemically and through imaging. The imaging features of the PHPT nodules, including the shape, margin, size, composition, and location, were evaluated before treatment. Serum intact parathyroid hormone, calcium, and phosphorus levels; parathyroid nodule volume; and PHPT-related symptoms were recorded before and after treatment. We calculated the technical success, biochemical cure, and clinical cure rates for these patients. Complications were evaluated during and after the ablation.

Results

Complete ablation was achieved in 38 of the 39 nodules in the 39 enrolled participants. All the patients were treated in one session. The technical success rate was 97.4% (38/39). The mean follow-up duration was 13.2 ± 4.6 (range, 6.0–24.9) months. At 6 and 12 months post-RFA, the biochemical cure rates were 82.1% (32/39) and 84.4% (27/32), respectively, and the clinical cure rates were 100% (39/39) and 96.9% (31/32), respectively. Only 2.6% (1/39) of the patients had recurrent PHPT. At 1, 3, 6, and 12 months after technically successful RFA, 44.7% (17/38), 34.3% (12/35), 15.8% (6/38), and 12.5% (4/32) of participants, respectively, had elevated eucalcemic parathyroid hormone levels. Recurrent laryngeal nerve paralysis occurred in 5.1% (2/39) of the patients, who recovered spontaneously within 1–3 months.

Conclusion

US-guided RFA was effective and safe for PHPT patients. RFA may be an alternative treatment tool for patients who cannot tolerate or refuse to undergo surgery.

Analysis and evaluation of the efficacy of ultrasound-guided microwave ablation for papillary thyroid microcarcinoma

OBJECTIVE

The choice of the most appropriate therapeutic approach for a diagnosed papillary thyroid microcarcinoma (PTMC) remains controversial. The present study aimed to evaluate the efficacy of microwave ablation (MWA) for unifocal PTMC with a diameter of ≤0.6 cm.

METHODS

A total of 63 consecutive patients with PTMC treated with MWA were studied retrospectively. MWA was performed using the hydrodissection technique and multidimensional fixed-needle principle. We analyzed the absorption of the MWA area and evaluated the prognosis over a follow-up period of 24 months. In addition, 83 patients with PTMC who underwent surgery were selected. The operating room characteristics and procedural complications of the two groups were compared.

RESULTS

In the MWA group, the volume of nodules (p < 0.05) decreased from 0.04 ± 0.03 cm³ to 0.0001 ± 0.0004 cm³ at the 24-month follow-up after MWA, and the volume reduction rate (p < 0.05) was 99.43 ± 1.58%. The incidence of temporary reactive hyperplastic lymphadenectasis was higher and that of other complications was lower in the MWA group than in the surgery group. One percent of the patients in the surgery group had recurrence or metastasis, but none were detected in the MWA group. The loss of thyroid tissue volume (p < 0.001), operating room time (p < 0.001), and the mean length of hospital stay (p < 0.001) were significantly lower in the MWA group than in the surgery group.

CONCLUSION

Ultrasound-guided MWA is an effective treatment strategy for unifocal PTMC with a diameter of ≤0.6 cm.

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.

A study on the causes of operative failures after microwave ablation for primary hyperparathyroidism

Objective

To summarize the occurrence of operative failures after microwave ablation (MWA) in patients with primary hyperparathyroidism (pHPT), analyze the possible reasons, and explore strategies for preventing and managing these situations.

Methods

This retrospective study reviewed 91 pHPT patients who underwent MWA from April 2015 to November 2019. A cure was defined as the reestablishment of normal calcium homeostasis lasting a minimum of 6 months. An operative failure was defined as a failure to normalize serum intact parathyroid hormone (iPTH) and/or calcium levels at 6 months or longer. Patients who encountered operative failures were compared with patients who were successfully cured.

Results

Eighty-eight pHPT patients, consisting of 29 men and 59 women, were finally enrolled. The median follow-up duration was 15.9 months (IQR, 6.1–31.5 months). Seventy-eight patients (78/88, 88.6%) were cured. Ten (10/88, 11.4%) patients experienced operative failure, including 9 persistent pHPT (10.2%) and 1 (1.1%) recurrent pHPT. Small parathyroid nodules (maximum diameter < 0.6 cm) and incomplete ablation were the two key factors leading to operative failure. Of the 9 patients with a maximum nodule diameter less than 0.6 cm, 77.8% (7/9) of them encountered operative failure.

Conclusion

Operative failure occurred in 11.4% of the pHPT patients who underwent MWA. The possibility of operative failure was increased when the maximum diameter of parathyroid nodule was less than 0.6 cm. Complete ablation could help avoid operative failure.

Key Points

• Failed to ablate the target lesion and incomplete ablation were the key factors attributed to operative failures.

• When the maximum diameter of the parathyroid nodules is less than 0.6 cm, the possibility of operative failure was higher.

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.

Bone Turnover Markers in Response to Ultrasound-Guided Microwave Ablation for Primary Hyperparathyroidism

OBJECTIVE

To assess the efficacy and safety of ultrasound-guided microwave ablation (MWA) in the treatment of primary hyperparathyroidism (PHPT), and to investigate whether MWA can improve the bone turnover and renal function.

METHODS

A total of 20 consecutive PHPT patients with 21 parathyroid lesions treated with MWA in our center from May 2019 to March 2021 were recruited in this study. Serum parathyroid hormone (PTH), calcium and phosphorus levels before MWA and at 20 minutes, 4 hours, 1 day, 3 months, 6 months and 12 months after MWA were measured. Bone turnover biomarkers, renal function and lesion volume with volume reduction rate (VRR) before MWA and at the last follow-up were compared. Any complication related with MWA was evaluated. The technical and clinical success rates of MWA in the treatment of PHPT were calculated. Clinical success was defined as normal serum PTH and calcium without PHPT-associated manifestations at more than 6 months after ablation. Technical success was defined as complete ablation indicated by immediate postoperative contrast-enhanced ultrasound.

RESULTS

The serum PTH, calcium and phosphorus levels at their respective follow-up time points dropped significantly after MWA (P <0.05). The volume of parathyroid lesions at the final examination was significantly reduced, compared with pre-ablation volume (P <0.001), with a median VRR reaching 89%. The technical and clinical success rates were 100% and 63.6%, respectively. Substantial changes of bone turnover biomarkers were observed before and after MWA (P <0.05), but the differences in renal function were not statistically significant. No major complications were reported in all cases. Pre-MWA serum PTH, lesion volume, maximum diameter of lesion and ablation time were significantly different between patients with successful and failed MWA.

CONCLUSIONS

PHPT can be effectively and safely treated by ultrasound-guided MWA, as proven by drop in serum PTH and reduction in the volume of parathyroid adenomas. Besides, MWA can impede bone remodeling to suppress hyperparathyroidism in the condition of PHPT.