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

The Parathyroid Gland: An Overall Review of the Hidden Organ for Radiologists

Parathyroid glands are small endocrine glands that regulate calcium metabolism by producing parathyroid hormone (PTH). These are located at the back of the thyroid gland. Typically, four glands comprise the parathyroid glands, although their numbers may vary among individuals. Parathyroid diseases are related to parathyroid gland dysfunction and can be caused by problems with the parathyroid gland itself or abnormal serum calcium levels arising from renal disease. In recent years, as comprehensive health checkups have become more common, abnormal serum calcium levels are often found incidentally in blood tests, after which several additional tests, including a PTH test, ultrasonography (US), technetium-99m sestamibi parathyroid scan, single-photon-emission CT (SPECT)/CT, four-dimensional CT (4D-CT), and PET/CT, are performed for further evaluation. However, the parathyroid gland remains an organ less familiar to radiologists. Therefore, the normal anatomy, pathophysiology, imaging, and clinical findings of the parathyroid gland and its associated diseases are discussed here.

Safety enhancement of improved hydrodissection for microwave ablation in secondary hyperparathyroidism

OBJECTIVE

To study the safety of improved hydrodissection based on the periparathyroidal fascial space during microwave ablation (MWA) for secondary hyperparathyroidism (SHPT).

MATERIALS AND METHODS

Data from 337 patients (162 males and 175 females; mean age, 50.8 ± 12.8 [range, 16-84] years) who underwent MWA for SHPT were retrospectively reviewed. Among them, 177 patients underwent traditional hydrodissection (traditional group) and 160 patients underwent improved hydrodissection based on periparathyroidal fascial spaces (improved group). Safety enhancement was analyzed by comparing the complications between the two groups. The characteristics of the hydrodissected fascial spaces, complications, and the follow-up results were recorded. The baseline data, clinical parameters, laboratory indices and characteristics of SHPT lesions were analyzed to assess the risk factors associated with hoarseness.

RESULTS

Hydrodissection was successfully performed in all the enrolled patients according to the protocol. Six periparathyroid fascial spaces were hydrodissected, depending on the location of the SHPT lesions. The incidence of hoarseness due to recurrent laryngeal nerve injury, the most common complication of thermal ablation for SHPT lesions, was lower in the improved group than in the traditional group (6.9% vs. 13.0%, p = 0.044). The median hoarseness recovery time in the improved group was shorter than that in the traditional group (2 vs. 6 months, p < 0.001). There was no difference in technical efficiency between the two groups (improved group vs. traditional group: 75.0% vs. 70.6%; p > 0.05).

CONCLUSIONS

Compared with traditional hydrodissection, improved hydrodissection based on periparathyroidal fascial spaces could enhance safety during MWA for SHPT.

Image-Guided Percutaneous Ablation for Primary and Metastatic Tumors

Image-guided percutaneous ablation methods have been further developed during the recent two decades and have transformed the minimally invasive and precision features of treatment options targeting primary and metastatic tumors. They work by percutaneously introducing applicators to precisely destroy a tumor and offer much lower risks than conventional methods. There are usually shorter recovery periods, less bleeding, and more preservation of organ parenchyma, expanding the treatment options of patients with cancer who may not be eligible for resection. Image-guided ablation techniques are currently utilized for the treatment of primary and metastatic tumors in various organs including the liver, pancreas, kidneys, thyroid and parathyroid, prostate, lung, bone, and soft tissue. This article provides a brief review of the various imaging modalities and available ablation techniques and discusses their applications and associated complications in various organs.