Made by DATEXIS (Data Science and Text-based Information Systems) at Beuth University of Applied Sciences Berlin
Deep Learning Technology: Sebastian Arnold, Betty van Aken, Paul Grundmann, Felix A. Gers and Alexander Löser. Learning Contextualized Document Representations for Healthcare Answer Retrieval. The Web Conference 2020 (WWW'20)
Funded by The Federal Ministry for Economic Affairs and Energy; Grant: 01MD19013D, Smart-MD Project, Digital Technologies
Treatment is usually surgical removal of the gland(s) containing adenomas, but medication may also be required.
Medications that are sometimes required include estrogen replacement therapy in postmenopausal women and bisphosphonates. Bisphosphonates may improve bone turnover.
Newer medications termed "calcimimetics" used in secondary hyperparathyroidism are now being used in primary hyperparathyroidism. Calcimimetics reduce the amount of parathyroid hormone released by the parathyroid glands. They are recommended in patients in whom surgery is inappropriate.
Medical management of OFC consists of Vitamin D treatment, generally alfacalcidol or calcitriol, delivered intravenously. Studies have shown that in cases of OFC caused by either end-stage renal disease or primary hyperparathyoidism, this method is successful not only in treating underlying hyperparathyoidism, but also in causing the regression of brown tumors and other symptoms of OFC.
Treatment depends entirely on the type of hyperparathyroidism encountered.
In people with secondary hyperparathyroidism, the high PTH levels are an appropriate response to low calcium and treatment must be directed at the underlying cause of this (usually vitamin D deficiency or chronic kidney failure). If this is successful PTH levels should naturally return to normal levels unless PTH secretion has become autonomous (tertiary hyperparathyroidism)
If the underlying cause of the hypocalcemia can be addressed, the hyperparathyroidism will resolve. In people with chronic renal failure, treatment consists of dietary restriction of phosphorus, supplements with an active form of vitamin D such as calcitriol, doxercalciferol, paricalcitol, etc. and phosphate binders which can be divided into calcium-based and non-calcium based.
Extended Release Calcifediol was recently approved by the FDA as a treatment for secondary hyperparathyroidism (SHPT) in adults with stage 3 or 4 chronic �kidney disease (CKD) and low vitamin D blood levels (25-hydroxyvitamin D less than 30 ng/mL). It can help treat SHPT by increasing Vitamin D levels and lowering parathyroid hormone or PTH. It is �not for patients with stage 5 CKD or on dialysis.
In the treatment of secondary hyperparathyroidism due to chronic kidney disease on dialysis calcimimetics do not appear to affect the risk of early death. It does decrease the need for a parathyroidectomy but caused more issues with low blood calcium levels and vomiting.
Most people with hyperparathyroidism secondary to chronic kidney disease will improve after renal transplantation, but many will continue to have a degree of residual hyperparathyroidism (tertiary hyperparathyroidism) post-transplant with associated risk of bone loss, etc.
In especially severe cases of OFC, parathyroidectomy, or the full removal of the parathyroid glands, is the chosen route of treatment. Parathyroidectomy has been shown to result in the reversal of bone resorption and the complete regression of brown tumors. In situations where parathyroid carcinoma is present, surgery to remove the tumors has also led to the regression of hyperparathyroidism as well as the symptoms of OFC.
Bone transplants have proven successful in filling the lesions caused by OFC. A report showed that in 8 out of 11 instances where cavities caused by OFC were filled with transplanted bone, the lesion healed and the transplanted bone blended rapidly and seamlessly with the original bone.
The treatment for hyperaldosteronism depends on the underlying cause. In people with a single benign tumor (adenoma), surgical removal (adrenalectomy) may be curative. This is usually performed laparoscopically, through several very small incisions. For people with hyperplasia of both glands, successful treatment is often achieved with spironolactone or eplerenone, drugs that block the effect of aldosterone. With its antiandrogen effect, spironolactone drug therapy may have a range of effects in males, including sometimes gynecomastia. These symptoms usually do not occur with eplerenone drug therapy.
In the absence of treatment, individuals with hyperaldosteronism often have poorly controlled high blood pressure, which may be associated with increased rates of stroke, heart disease, and kidney failure. With appropriate treatment, the prognosis is excellent.
Treatment includes spironolactone, a potassium-sparing diuretic that works by acting as an aldosterone antagonist.
Parathyroid auto transplantation is part of the treatment when a patient has hyperparathyroidism and three or four parathyroid glands were already removed, but during the surgery one of the glands (in the case of the removal of three) is relocated at another part of the body to make, the procedure less risky another procedure. In the case of complete parathyroidectomy, a half gland is cryopreserved. In case the patient suffers hypoparathyroidism. If this happens the extracted parathyroid is relocated to another place of the body for example the forearm. Parathyroid auto transplantation begins with parathyroid tissue extraction, which must be preserved into a cold isotonic solution until the patient needs it. Research has shown that parathyroid tissue can function at subcutaneous level until the transplantation. If this is not possible, the most common procedure is to create a small pocket of muscle, tissue at least 2 cm deep by separating the muscular fibers. Then the parathyroid tissue is placed into and closed by suturing the area. After the extraction the tissue might be processed at the laboratory, as soon as possible. Once at the laboratory the tissue sample is placed at a frozen petri dish where it is cut into small pieces (approximately 1–2 mm). The small pieces are placed into test tubes and filled with a solution in three parts one at 20% of autologous serum (about 0.6 ml) and the other part of isotonic solution at 20% (about 0.6 ml) then a solution of 2 ml of polypropylene and mixed gently. Then is placed into a container at -70 °C for a night then finally the container passes through the phase of liquid or vapor nitrogen immersion and is kept there until needed. When it is needed the sample is taken out of the nitrogen and placed into a bath of water at 37 °C until the ice is melted almost completely except for the samples core. Then 0.5 ml of the melted solution is removed and replaced for fresh isotonic solution.
Parathyroidectomy, or the removal of the parathyroids, requires general anesthesia. The patient is intubated and placed in a supine position with the chin at fifteen degrees by elevating the shoulders to permit the extension of the neck. Then a transverse cut is made above the sternal notch. The transversal thyroid lobe is reached and is rotated up to discover and ligate the thyroid vein to separate the thyroid artery. Exploration must be done meticulously to search for adenomas. If an adenoma is identified, exploration must be continued because it is common that more than one neoplasia appears. Before the procedure, the glands are marked to make them more visible during the procedure. If one of them cannot be found, the procedure is to remove a complete thyroid lobe on the side where the gland is not found to avoid an intrathyroid parathyroid gland. After exploration, if there is one, two or even three parathyroid glands affected, they are removed and the other one left in situ. If all four glands are affected then three and a half are removed. The remaining half is marked with a suture and the surgeon must be sure that the blood supply will not be compromised. A total parathyroidectomy or auto transplantation to the forearm of the remaining half gland, may also be recommended.
The goal of therapy is to treat the hypercalcaemia first and subsequently effort is directed to treat the underlying cause.
Initial therapy:
- hydration, increasing salt intake, and forced diuresis.
- hydration is needed because many patients are dehydrated due to vomiting or kidney defects in concentrating urine.
- increased salt intake also can increase body fluid volume as well as increasing urine sodium excretion, which further increases urinary potassium excretion.
- after rehydration, a loop diuretic such as furosemide can be given to permit continued large volume intravenous salt and water replacement while minimizing the risk of blood volume overload and pulmonary oedema. In addition, loop diuretics tend to depress calcium reabsorption by the kidney thereby helping to lower blood calcium levels
- can usually decrease serum calcium by 1–3 mg/dL within 24 hours
- caution must be taken to prevent potassium or magnesium depletion
Treatment for renal osteodystrophy includes the following:
- calcium and/or native vitamin D supplementation
- restriction of dietary phosphate (especially inorganic phosphate contained in additives)
- phosphate binders such as calcium carbonate, calcium acetate, sevelamer hydrochloride or carbonate, lanthanum carbonate, sucroferric oxyhydroxide, ferric citrate among others
- active forms of vitamin D (calcitriol, alfacalcidol, paricalcitol, maxacalcitol, doxercalciferol, among others)
- cinacalcet
- renal transplantation
- haemodialysis five times a week is thought to be of benefit
- parathyroidectomy for symptomatic medication refractive end stage disease
Surgery is the only cure for parathyroid adenomas. It is successful about 95% of the time. Parathyroidectomy is the removal of the affected gland(s). The standard of treatment of primary hyperparathyroidism was formerly a surgical technique called bilateral neck exploration, in which the neck was opened on both sides, the parathyroids were identified, and the affected tissue was removed. By the 1980s, unilateral exploration became more common. Parathyroidectomy can now be performed in a minimally invasive fashion, mainly because imaging techniques can pinpoint the location of the tissue. Minimally invasive techniques include smaller open procedures, radio-guided and video-assisted procedures, and totally endoscopic surgery.
Before surgery is attempted, the affected glandular tissue must be located. Though the parathyroid glands are usually located on the back of the thyroid, their position is variable. Some people have one or more parathyroid glands elsewhere in the neck anatomy or in the chest. About 10% of parathyroid adenomas are ectopic, located not along the back of the thyroid but elsewhere in the body, sometimes in the mediastinum of the chest. This can make them difficult to locate, so various imaging techniques are used, such as the sestamibi scan, single-photon emission computed tomography (SPECT), ultrasound, MRI, and CT scans. sometimes parathyroid adenomas can be ablated by ethanol injection, guided by ultrasound.
Surgical resection of the tumor is the treatment of first choice, either by open laparotomy or laparoscopy. Given the complexity of perioperative management, and the potential for catastrophic intra and postoperative complications, such surgery should be performed only at centers experienced in the management of this disorder. In addition to the surgical expertise that such centers can provide, they will also have the necessary endocrine and anesthesia resources. It may also be necessary to carry out adrenalectomy, a complete surgical removal of the affected adrenal gland(s).
Either surgical option requires prior treatment with the non-specific and irreversible alpha adrenoceptor blocker phenoxybenzamine or a short acting alpha antagonist (e.g. prazosin, terazosin, or doxazosin). Doing so permits the surgery to proceed while minimizing the likelihood of severe intraoperative hypertension (as might occur when the tumor is manipulated). Some authorities would recommend that a combined alpha/beta blocker such as labetalol also be given in order to slow the heart rate. Regardless, a nonselective beta-adrenergic receptor blocker such as propranolol must never be used in the presence of a pheochromocytoma. The mechanism for β-adrenoceptor blocker-associated adverse events is generally ascribed to inhibition of β2-adrenoceptor-mediated vasodilatation, leaving α1-adrenoceptor-mediated vasoconstrictor responses to catecholamines unopposed and, thus, severe and potentially refractory hypertension. However some clinical guidelines permit beta-1 blockade use together with alpha blockers during surgery for control of tachycardia.
The patient with pheochromocytoma is invariably volume depleted. In other words, the chronically elevated adrenergic state characteristic of an untreated pheochromocytoma leads to near-total inhibition of renin-angiotensin activity, resulting in excessive fluid loss in the urine and thus reduced blood volume. Hence, once the pheochromocytoma has been resected, thereby removing the major source of circulating catecholamines, a situation arises where there is both very low sympathetic activity and volume depletion. This can result in profound hypotension. Therefore, it is usually advised to "salt load" pheochromocytoma patients before their surgery. This may consist of simple interventions such as consumption of high salt food pre-operatively, direct salt replacement or through the administration of intravenous saline solution.
Clinical trials of protein kinase inhibitors, which block the abnormal kinase proteins involved in the development and growth of medullary cancer cells, showed clear evidence of response in 10-30% of patients. In the majority of responders there has been less than a 30% decrease in tumor mass, yet the responses have been durable; responses have been stable for periods exceeding 3 years. The major side effects of this class of drug include hypertension, nausea, diarrhea, some cardiac electrical abnormalities, and thrombotic or bleeding episodes.
Vandetanib, trade name Caprelsa, was the first drug (April 2011) to be approved by US Food and Drug Administration (FDA) for treatment of late-stage (metastatic) medullary thyroid cancer in adult patients who are ineligible for surgery.
Cabozantinib, trade name Cometriq, was granted marketing approval (November 2012) by the U.S. FDA for this indication. Cabozantinib which is a potent inhibitor of RET, MET and VEGF was evaluated in a double-blind placebo controlled trial. It was shown to improve overall survival by 5 months for the treated cohort vs. placebo, which was not statistically significant. However, cabozantinib was particularly effective in patients with the RET M918T mutation, extending overall survival by roughly 2 years, doubling survival vs. untreated patient (4 years vs. 2 year). Treatment with cabozantinib did require many dose reduction to mitigate side effects. It has been suggested that the trial dose of 140 mg was excessive, particularly in lower body mass patients. Ongoing trials have been scheduled to identify more optimal dosing regimes. Activity has been observed, in practice at doeses of 1.2 mg/kg.
No treatment is generally required, as bone demineralisation and kidney stones are relatively uncommon in the condition.
High phosphate levels can be avoided with phosphate binders and dietary restriction of phosphate. If the kidneys are operating normally, a saline diuresis can be induced to renally eliminate the excess phosphate. In extreme cases, the blood can be filtered in a process called hemodialysis, removing the excess phosphate.
Treatment involves having the person stop taking any calcium supplements and any other alkali agents they have been taking, and hydration.
In severe cases, hospitalization may be required, in which case saline may be administered intravenously.
If kidney failure is advanced then treatment for that is required, namely chronic dialysis.
External beam radiotherapy is recommended when there is a high risk of regional recurrence, even after optimum surgical treatment. In this study, patients treated with external beam radiation were compared to a control group. Disease control with radiation was far superior in the group receiving radiation. The authors of the study [14] wrote: "in 40 high risk patients (microscopic residual disease, extraglandular invasion, or lymph node involvement), the local/regional relapse free rate was 86% at 10 years with postoperative external beam radiation (25 patients), and 52% for those with no postoperative external radiation (p = 0.049). To optimize local/regional tumor control, we therefore continue to advise external beam radiation in patients at high risk of local/regional relapse."
Unlike other differentiated thyroid carcinoma, there is no role for radioiodine treatment in medullary-type disease.
If left untreated, the disease will progress to tertiary hyperparathyroidism, where correction of the underlying cause will not stop excess PTH secretion, i.e. parathyroid gland hypertrophy becomes irreversible. In contrast with secondary hyperparathyroidism, tertiary hyperparathyroidism is associated with hypercalcemia rather than hypocalcemia.
Management of MEN2 patients includes thyroidectomy including cervical central and bilateral lymph nodes dissection for MTC, unilateral adrenalectomy for unilateral pheochromocytoma or bilateral adrenalectomy when both glands are involved and selective resection of pathologic parathyroid glands for primary hyperparathyroidism.
Familial genetic screening is recommended to identify at risk subjects who will develop the disease, permitting early management by performing prophylactic thyroidectomy, giving them the best chance of cure.
Prognosis of MEN2 is mainly related to the stage-dependant prognosis of MTC indicating the necessity of a complete thyroid surgery for index cases with MTC and the early thyroidectomy for screened at risk subjects.
Tertiary hyperparathyroidism is a state of excessive secretion of parathyroid hormone (PTH) after a long period of secondary hyperparathyroidism and resulting in a high blood calcium level. It reflects development of autonomous (unregulated) parathyroid function following a period of persistent parathyroid stimulation.
The basis of treatment is still prevention in chronic kidney failure, starting medication and dietary restrictions long before dialysis treatment is initiated. Cinacalcet has greatly reduced the number of patients who ultimately require surgery for secondary hyperparathyroidism; however, approximately 5% of patients do not respond to medical therapy.
When secondary hyperparathyroidism is corrected and the parathyroid glands remain hyperfunctioning, it becomes tertiary hyperparathyroidism. The treatment of choice is surgical removal of three and one half parathyroid glands.
Parathyroid carcinoma is sometimes diagnosed during surgery for primary hyperparathyroidism. If the surgeon suspects carcinoma based on severity or invasion of surrounding tissues by a firm parathyroid tumor, aggressive excision is performed, including the thyroid and surrounding tissues as necessary.
Agents such as calcimimetics (for example, cinacalcet) are used to mimic calcium and are able to activate the parathyroid calcium-sensing receptor (making the parathyroid gland "think" we have more calcium than we actually do), therefore lowering the calcium level, in an attempt to decrease the hypercalcemia.