Parathyroid glands – a chance for a breakthrough in the diagnosis of “insidious” glands

Parathyroid glands, of which a person may have four, but just as well more, on imaging studies are sometimes surprisingly similar to… lymph nodes and thyroid nodules. Assessing which of several parathyroid glands is responsible for excessive parathormone production has until now often only been possible during surgery. What’s new in the diagnosis of parathyroid glands, glands that cleverly hide their nature from patients and doctors, says Lt. Col. dr n. med. Andrzej Mazurek of the Polish Society of Nuclear Medicine.

Lt. Col. Dr. n. med. Andrzej Mazurek is head of the Radiopharmaceutical Quality Control Laboratoryoat the Department of Nuclear Medicine of the Military Medical Institute and an expert of the Polish Society of Nuclear Medicine.

Doctor, what are parathyroid glands and what functions in the human body they perform?

Parathyroid glands are glands located in the thyroid area (hence their name), whichoThe mainoAn important function in the body is to keep the concentration of calcium and phosphorus at a constant level. There are usually four parathyroid glands, located near the posterior surface of the thyroid gland. In some patientsoHowever, there may be more in the parathyroid glands and they may be located atypically – for example, in the chest. The parathyroid glands secrete a hormone called parathormone.

What disorders and diseases most commonly affect the parathyroid glands?

The most common condition, for which theore these glands collapse, is primary hyperparathyroidism. This is a condition in whichorym one or more parathyroid glands secrete too much parathormone. Word „primary” means that the problem lies in the comorks of the parathyroid glands themselves, in the odroThe disease is a result of „wtornej” Hyperparathyroidism, where the mainohe root cause of the condition is located outside the parathyroid glands – this is the case, among others, in renal failure, where hyperparathyroidism is a consequence of another disease.

Primary hyperparathyroidism is one of the most common diseasesob endocrine system (i.e., endocrine disorders) and remains a huge challenge – zaroboth for doctors and patientsow. The disease is often asymptomatic for many years. The only symptom of the disease may be elevated (even slightly) calcium levels in the blood, so it can take up to 10 years from the onset of the disease to the start of treatment.

Once there are noticeable symptoms of hyperparathyroidism, they affect virtually every part of the body, just not the neck (which is where the parathyroid glands are located). Symptoms often mislead zaroboth the patient and the doctor. Hyperparathyroidism can be accompanied, for example, by nephrolithiasis (manifested by renal colic), bobone lesions and fractures without major trauma, bole of the abdomen (due to gastric or duodenal ulcer), psychiatric disorders, calcifications in the roof other organs (for example, in heart valves).

How to treat hyperparathyroidism?

Once primary hyperparathyroidism is diagnosed, the only way to cure the disease is to surgically remove the parathyroid gland responsible for excessive parathormone secretion, and here again we face a challenge – the parathyroid gland responsible for the disease must be found before surgery. Until recently, there was no good imaging method to look for hyperactive parathyroidism. Often, the surgeon only looked for the right gland, that is, the particular one responsible for excessive parathormone production, after dissecting the neck tissues. The problem arose when the parathyroid gland responsible for the disease was not located in the neck, but in the chest.

What diagnostic tests are performed to study parathyroid function?

Usually laboratory tests are performed at the beginning: blood calcium and parathormone levels are determined, as well as urinary calcium excretion. Imaging studies are performed to localize hyperparathyroidism. In the first instance, such a study is an ultrasound of the neck. Unfortunately, at this stage „sneaky” The parathyroid glands pose another conundrum for doctors – a hyperactive parathyroid gland is quite similar to a lymph node or thyroid nodule, so the appropriate rozroThe reason is sometimes not obvious.

Besides, when the parathyroid gland is located in the chest, ultrasound is useless. Sometimes roAlso computed tomography (CT) and magnetic resonance imaging (MRI) of the neck/chest. Interestingly, also in these studies, the parathyroid roAlso, it is similar to lymph node. Of the isotopic tests for parathyroid diagnosis, subtractive scintigraphy of the thyroid and parathyroid glands has been performed so far – Unfortunately, this method rois also not without its drawbacks: there are great difficulties in visualizing parathyroid glands of small dimensions, and detachedodistinguishing the parathyroid glands from a thyroid nodule can be quite a challenge.

Is there a chance for a breakthrough in parathyroid diagnosis?

A breakthrough in imaging of hyperparathyroidism may be PET, or positron emission tomography, using radioactive fluorine-labeled choline (PET/CT with 18F- choline). In our center, we have very good experience with this imaging method. To date, we have performed PET/CT with 18F- choline in nearly 60 patientsoIn with hyperparathyroidism (mainlyownie with the primary form) and in about 80-90 percent of. patients have been able to find hyperactive parathyroid glands. Importantly, this group of patients was previously diagnosed by other imaging modalities, and in most patientsoIn other methods have failed.

Can diagnostics using radioactive fluorine-labeled choline be offered to patients?

Our findings and the results from the roof the different centersoin foreign suggest that the 18F- choline PET/CT method may be a breakthrough in localizing hyperparathyroidism. The problem in performing this test is not the availability of scanneroIn PET/CT or 18F- choline radioimmunoassay, but no reimbursement for the test itself. It should be added that the radiolabeled 18F- choline is not an experimental substance. This is a radio-antigen firstly well known, secondly – approved for use in Poland, and in addition – reimbursed by the National Health Fund in the patientow with clear cell carcinomaor cancer of the kidney and with prostate cancer. Added to the criteriaoin reimbursement of the indication, which is hyperparathyroidism, would make it possible for us to perform such a study widely in Poland. This is certainly worth considering. From myoin with endocrinology specialists and surgeons involved in the treatment of hyperparathyroidism, it appears that such a test would help many patients.