Parathyroid Changes After RAI in Patients With Differentiated Thyroid Carcinoma.

Objective: The purpose of this study was to investigate parathyroid hormone (PTH), serum calcium, phosphorus, and 25-hydroxyvitamin D (25-OH-VD) changes before and after radioactive iodine (RAI) in differentiated thyroid carcinoma (DTC) patients at different time points. Methods: A total of 259 DTC patients who received RAI were prospectively enrolled. We evaluated PTH, serum calcium, phosphorus, and 25-OH-VD levels at baseline pre-RAI, five days, six weeks, and six months post-RAI, respectively. We analyzed the risk factors of hypocalcemia at five days post-RAI. Results: The mean PTH, serum calcium and phosphorus values decreased five days post-RAI compared with pre-RAI (PTH 4.18 ± 1.23 pmol/L vs. 3.95 ± 1.41 pmol/L; calcium 2.27 ± 0.09 mmol/L vs. 2.20 ± 0.11 mmol/L; phosphorus 1.25 ± 0.17 vs. 0.98 ± 0.20 mmol/L, P < 0.05), and the differences were statistically significant. The mean 25-OH-VD levels did not significantly decrease at five days post-RAI. 21.2% (55/259) of patients had hypocalcemia at five days post-RAI, and all of them were given oral calcium supplements. At six weeks post-RAI, all of the above parameters were higher than those at five days post-RAI. Multivariate regression analysis showed that baseline pre-RAI serum calcium < 2.27 mmol/L, PTH < 4.18 pmol/L and negative 99mTcO4- thyroid imaging were risk factors for hypocalcemia at five days post-RAI. Conclusion: For DTC patients with normal PTH and serum calcium levels at pre-RAI, their PTH, serum calcium, and phosphorus levels decreased at five days post-RAI. About one-fifth of patients could have hypocalcemia at five days post-RAI. Lower baseline pre-RAI serum calcium and PTH levels and negative 99mTcO4- thyroid imaging were risk factors for hypocalcemia five days post-RAI.

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.

Pilot study of parathyroid glands in adult and pediatric subjects exposed to ionizing radiation after the ChNPP accident, methodology of parathyroid diagnostic ultrasound. / PILOTNE DOSLIDZhENNIa STANU PRYShchYTOPODIBNYKh ZALOZ OSIB, OPROMINENYKh VNASLIDOK AVARIÏ NA ChAES DOROSLOGO TA DYTIaChOGO VIKU, METODOLOGIIa ÏKh UL'TRAZVUKOVOGO DOSLIDZhENNIa.

OBJECTIVE: Estimation of the parathyroid hyperplasia prevalence after the ChNPP accident in adults exposed to ion izing radiation and their descendants using the diagnostic ultrasound and its methodology elaboration. MATERIALS AND METHODS: The pilot prospective study of the prevalence of parathyroid hyperplasia among the Chornobyl Nuclear Power Plant (ChNPP) accident adult survivors (n=686) and their descendants (54 children) was performed using diagnostic ultrasound examination of thyroid and parathyroids. Among the study subjects there were 339 ChNPP accident clean up workers (ACUW), 32 persons were evacuated from the 30 km exclusion zone and 224 ones were included to the control group. Diagnostic ultrasound of thyroid and parathyroids was performed according to the standard method. Additionally, in children with parathyroid hyperplasia an additional assay of 25 hydroxyvitamin D levels in serum was performed. In calculating the statistical significance, its level p < 0.05 was considered statistically significant. RESULTS: Parathyroids are a few small but critically important endocrine glands that synthesize parathyroid hormone, regulating mainly phosphoric calcium metabolism. Insufficient (hypoparathyroidism) or excessive (hyperparathy roidism) function of parathyroids is harmful to the patients affecting the state of nervous and cardiovascular sys tem. Parathyroidss can accumulate isotopes of cesium, strontium and radioactive iodine. The available data testify to an increased incidence of clinically significant hyperplasia of parthyroids (more than 9 mm in adults and more than 5 mm in children) among persons exposed toionizng radiation as a result of the accident at the ChNPP (28.64%) and their descendants (23.8-70.6%). First of all are concerned those adults who live in contaminated areas in comparison with the control group (24.15% in not irradiated). Evacuees from the 30 km exclusion zone being the category of people who were exposed to the absorbed iodine isotopes in the first days of the Chernobyl accident are the another risk group. These data demonstrate sensitivity of parathyroidss to the impact of incorpo rated isotopes (iodine, cesium and strontium), which in the long term exposure create conditions for structural and functional changes in regulation of phosphorous calcium metabolism being the basis for a significant prevalence of osteopenia and osteoporosis in irradiated individuals and their descendants. A number of further studies are required to clarify the findings and to disclose the hormonal mechanisms of radiation effects on parathyroids. CONCLUSIONS: Parathyroid glands are radiosensitive and susceptible to effects of strontium, cesium and iodine iso topes, which cause parathyroid irradiation and subsequent structural and functional changes, being a prerequisite for development of osteopenia and osteoporosis in the ChNPP accident survivors and their descendants. High inci dence of parathyroid hypertrophy is found in the inhabitants of the radiation contaminated territories (long term irradiation by cesium isotopes), as well as in evacuated from the 30 km exclusion zone (irradiation by iodine iso topes in the early days of the accident).

Parathyroid changes after high dose radioactive iodine in patients with thyroid cancer.

OBJECTIVE: The study aimed to investigate the effect of high dose radioactive iodine (RAI) on parathyroid function in patients with differentiated thyroid cancer. METHODS: Nineteen patients (8 men/11 women, age 46.5 +/- 13.2 years) undergoing RAI for thyroid remnant ablation were enrolled in the study. The biochemical parameters related to parathyroid function [serum calcium (Ca), phosphate (P), creatinine (Cr), alkaline phosphatase (ALP), intact parathyroid hormone (iPTH), urinary Ca, cAMP concentrations and the maximum tubular capacity for phosphate per unit volume of glomerular filtrate (TmP/GFR)] were evaluated at baseline and at the 1st, 3rd, 6th and 12th months of RAI administration. SPSS 15.0 was used for statistical analysis. RESULTS: For all patients, thyroid-stimulating hormone levels were >30 U/ml at baseline and <0.1 U/ml at the following visits. Serum iPTH levels were decreased significantly at the 6th month and reached basal levels at the 12th month (baseline vs. 6th p = 0.027, 1st vs. 6th p = 0.011, 3rd vs. 6th p = 0.047, 3rd vs. 12th p = 0.014, 6th vs. 12th p = 0.001). At the 6th month, P and TmP/GFR levels were higher (p = 0.036, 0.017, respectively), and urinary cAMP measurements were lower (p = 0.020) compared to those of the 1st month. No difference was detected concerning the other parameters. Serum Ca levels decreased below 2.1 mmol/l in several patients (n = 5 at 1st month, n = 4 at 3rd month, n = 8 at 6th month and n = 3 at 12th month) without clinical symptoms. CONCLUSIONS: The study indicated a transient decline in PTH levels at the 6th month following RAI therapy. Although this decrease did not cause symptoms in any of the present cases, this pattern might be important especially in individuals with diminished parathyroid background.

Is the treatment of Hodgkin's disease detrimental to the parathyroid gland?

The thyroid gland is often injured by supradiaphragmatic irradiation for Hodgkin's lymphoma. The aim of the present study was to examine whether the parathyroid gland gets injured by the treatment for Hodgkin's disease. Calcium, phosphorus and parathormone levels of 143 patients with primary treatment for Hodgkin's disease and in complete remission for 2 years were measured as well as the presence of antiparathyroid antibody in patients having antithyroid antibody. Out of the 143 patients studied, 104 received neck irradiation (with or without chemotherapy); among them laboratory alterations were observed in 7 cases. 39 patients received only chemotherapy; 3 of them had alterations. In contrast to the injury of the thyroid gland, no damage to the parathyroid glands associated with the treatment for Hodgkin's disease was noted. It has been concluded that the use of high-dose external radiotherapy does not mean a higher risk as regards the parathyroid gland but further follow-up studies of the patients may result in the revelation of the development of parathyroid lesions.

[The correction of the subcellular postradiation changes in the hypothalamus and parathyroid gland by using low-intensity laser radiation (an experimental study)]. / Korrektsiia subkletochnykh postradiatsionnykh izmenenii v gipotalamuse i parashchitovidnoi zheleze pri ispol'zovanii nizkointensivnogo lazernogo izlucheniia (éksperimental'noe issledovanie).

The exposure of the rat adrenals 30 days after radiation (1 Gy) to low-intensity infrared laser radiation arrests development of ultrastructural disorders in the cells of hypothalamus and parathyroid gland, enhances subcellular manifestations of adaptation and rehabilitation processes.

Parathyroid hormone secretory reserve in patients submitted to 131-iodine therapy for hyperthyroidism

Twelve euthyroid patients who had treated with I for hyperthyroidism due to Fraves' disease and six normal controls were submitted to an EDTA infusion test. Ionized calcium and parthyroid hormone were measured in serum samples collected every 10 min during the 2-h-test. Basal values for calcium (1.22 ñ 0.03 vs 1.23 ñ 0.03 pmol/l, mean ñ SD, controls vs patients) and parathyroid hormone (3.3 ñ 0.65 vs 5.5 ñ 2.32 pmol/l_ as well as maximum response during infusion (1.01 ñ 0.04 vs 1.01 ñ 0.05 for calcium and 12.0 ñ 2.2 vs 13.1 ñ 3.7 for parathyroid hormone) were not significantly different. We conclude that I treatment for hyperthyroidism due to Graves' disease had no effect on the parathyroid gland secretory reserve of the patients studied

Early changes in parathyroid function after high-dose irradiation of the neck.

Hyperparathyroidism (HPT) will develop years later in a number of patients irradiated to the neck for benign diseases. Twenty-nine patients with malignant diseases were studied for 3 years after irradiation with cancer therapeutic doses to the neck. The serum concentration of parathyroid hormone (iPTH) showed an increasing trend suggesting that HPT also might develop in these patients.

Effect of decicurie doses of radioactive iodine 131 on parathyroid function.

Although parathyroid deficiency has been reported after administration of relatively small doses of iodine 131, reports of such deficiency after the much larger doses given in the management of thyroid cancer are notable by their absence in the literature. We observed one such patient, then instituted a prospective study. We observed a 58 percent incidence of apparently diminished parathyroid reserve among 53 patients given high doses of I 131. Susceptibility does not appear to be related to age, sex, extent of thyroid operation, operative technique, the amount of thyroidal I 131 uptake, the use of external radiation to the neck, or to the presence of parathyroid glands or of Hashimoto's disease in the operative specimen; however, susceptibility may be related to the anatomic location of the parathyroid glands in relation to the thyroid gland. The administered dose of I 131 almost reached significant levels (p = 0.1) in the present study. The initial pretreatment serum calcium levels were consistently lower among affected patients (p = 0.01), suggesting the presence of a preexisting latent impairment of parathyroid reserve which was subsequently unmasked after the administration of I 131. Thyroid cancer is compatible with very long-term survival, and therefore, there is a considerable risk of delayed chronic hypocalcemia among patients who have received large doses of I 131, particularly female patients in the premenopausal age group. These patients deserve special management surveillance.

Primary hyperparathyroidism and nonmedullary thyroid cancer.

Of 2,058 patients who had surgically proven primary hyperparathyroidism at the Mayo Clinic from 1965 through 1979, 51 or 2.5 percent had associated nonmedullary thyroid carcinoma. A history of radiation exposure to the head and neck was obtained in 14 of 43 patients questioned. Thyroid disease consisted of grade 1 papillary adenocarcinoma in 48 cases and pure follicular adenocarcinoma in 3 cases. The parathyroid disease included 41 single adenomas and 5 cases of parathyroid hyperplasia; 5 patients had 2 adenomas. At follow-up, none of the patients had evidence of metastatic thyroid carcinoma. Ten patients were receiving calcium or vitamin D supplementation for protracted hypocalcemia presumably due to the increased insult to the parathyroids from combined bilateral thyroidectomy and parathyroidectomy. More consecutive thyroidectomy, along with parathyroid autotransplantation when indicated, will provide definitive treatment of the thyroid cancer and at the same time minimize the risk of postoperative hypoparathyroidism.