Efficacy of 99mTc-DTPA SPECT/CT in diagnosing Orbitopathy in graves' disease.

BACKGROUND: The most frequently used methods of assessing Graves' orbithopathy (GO) include: Clinical Activity Score (CAS), ultrasonography (USG), computed tomography (CT), and magnetic resonance imaging (MRI). There exists another, slightly forgotten, imaging method: single-photon emission computed tomography (SPECT) with the use of diethylenetriaminepentaacetic acid tagged with 99mTc (99mTc-DTPA). These days it is possible to conduct a SPECT examination fused with a CT scan (SPECT/CT), which increases the diagnostic value of the investigation. The aim of this paper is to evaluate the usefulness of 99mTc-DTPA SPECT/CT in diagnosing Graves orbitopathy, as compared with other methods. METHODS: Twenty-three patients with suspected active (infiltrative-edematous) Graves' orbithopathy were included in the study. Each patient underwent a CAS, an MRI, and a SPECT/CT. The obtained results were analysed statistically, with the assumed statistical significance of p < 0.05. RESULTS: The SPECT/CT and MRI were found to have the highest sensitivity: 0.93 each. The SPECT/CT had the highest specificity: 0.89. MRI and CAS had lower values: 0.78 and 0.56, respectively. The occurrence of an active form of GO had no impact on the exacerbation of exophthalmos or the thickness of the oculomotor muscles. CONCLUSIONS: The 99mTc-DTPA SPECT/CT method provides a very good tool for assessing the active form of GO and can, alongside the MRI scan, be used as a referential diagnostic procedure in GO.

Assessment of Clinical Utility of Assaying FGF-23, Klotho Protein, Osteocalcin, NTX, and Sclerostin in Patients with Primary Hyperparathyroidism.

The purpose of this study was to assess the clinical usefulness of assaying the fibroblast growth factor (FGF-23), Klotho, osteocalcin, N-terminal telopeptide of type I collagen (NTX), and sclerostin levels in patients with primary hyperparathyroidism (PHPT) as markers of bone damage as well as for surgical treatment success. Seventeen patients with hypercalcemic PHPT and normal kidney function were studied. In all patients, PTH (parathormone), serum calcium, and creatinine were performed before and six months after parathyroidectomy (PTX). The studied group included patients whose PTH and calcium concentrations normalized post-operatively and with confirmed histopathological diagnosis. The control group consisted of nine age-matched healthy volunteers. The PHPT patients had elevated concentrations of FGF-23, osteocalcin, and NTX and reduced levels of sclerostin, as compared to the control group. After PTX, osteocalcin, NTX, and sclerostin levels normalized. The plasma values of FGF-23 decreased significantly, but remained higher than in healthy subjects. Serum Klotho protein levels did not differ significantly in the two groups. These results suggest that osteocalcin and NTX may potentially be considered as markers of PHPT progression. Additionally, serum normalization of osteocalcin, NTX, and sclerostin might be considered as indicators of PTX success. On the other hand, FGF-23 can represent a parameter reflecting the degree of calcium-phosphate imbalance in PHPT patients, but its usefulness in monitoring the effects of PTX requires further research. The clinical utility of assaying Klotho in PHPT remains to be confirmed.

Dosimetry during adjuvant 131I therapy in patients with differentiated thyroid cancer-clinical implications.

The activity of radioiodine (131I) used in adjuvant therapy for thyroid cancer ranges between 30 mCi (1.1 GBq) and 150 mCi (5.5 GBq). Dosimetry based on Marinelli's formula, taking into consideration the absorbed dose in the postoperative tumour bed (D) should systematise the determination of 131I activity. Retrospective analysis of 57 patients with differentiated thyroid cancer (DTC) after thyreidectomy and adjuvant 131I therapy with the fixed activity of 3.7 GBq. In order to calculate D from Marinelli's formula, the authors took into account, among other things, repeated dosimetry measurements (after 6, 24, and 72 h) made during scintigraphy and after administration of the therapeutic activity or radioiodine. In 75% of the patients, the values of D were > 300 Gy (i.e. above the value recommended by current guidelines). In just 16% of the patients, the obtained values fell between 250 and 300 Gy, whereas in 9% of the patients, the value of D was < 250 Gy. The therapy was successful for all the patients (stimulated Tg < 1 ng/ml and 131I uptake < 0.1% in the thyroid bed in follow-up examination). Dosimetry during adjuvant 131I therapy makes it possible to diversify the therapeutic activities of 131I in order to obtain a uniform value of D.

Enhancing the efficacy of 131I therapy in non-toxic multinodular goitre with appropriate use of methimazole: an analysis of randomized controlled study.

PURPOSE: It is possible to raise the rate of the uptake of 131I in the thyroid gland (RAIU) by increasing the endogenous TSH level through appropriate use of methimazole (MMI) prior to 131I therapy. The purpose of this paper is to assess the impact of pre treatment with MMI on the efficacy of 131I therapy in non-toxic multinodular goitre (NMG). METHODS: Thirty-one patients with NMG received 131I treatment in order to reduce the volume of the thyroid (TVR). Those in group 1 (n = 16) were administered 10 mg of methimazole for 6 weeks. Four days after its discontinuation, they received 131I. Patients in group 2 (n = 15) were given a placebo instead of MMI. The therapeutic activity of 131I was constant (800 MBq) and was repeated every 6 months. Treatment was discontinued when TVR reached <40 ml. RESULTS: In group 1, RAIU increased approximately twofold. Ten patients from group 2 and four patients from group 1 received further doses of 131I. The median of time until TVR decreased below 40 ml was 9 months [6-12 months] and 18 months [14-22 months] in group 2. At 2 years after the 131I therapy, the occurrence of hypothyroidism did not differ significantly (36% in group 1 and 33% in group2, p = 0.074). CONCLUSIONS: Radioiodine treatment of NMG preceded with appropriate application of MMI is efficient thanks to increased RAIU, shorter period of treatment, and lower frequency of 131I administration, without an increase in the incidence of post-treatment hypothyroidism.

Value of direct radionuclide cystography in diagnosing vesico-peritoneal fistulae.

A 36-year-old female patient underwent a laparoscopic surgery to remove a uterine fibroid. The procedure failed to relieve the pelvic pain, although its nature changed. After a period of observation, the patient was re-admitted to hospital on suspicion of a vesico-uterine fistula to be differentiated with endometriosis. Diagnostic investigations - cystography, cystoscopy, computed tomography and magnetic resonance - did not reveal a fistula. Laparoscopy was performed, with a possible biopsy in order to eliminate endometriosis. The result was negative, but chronic progressive reactive/inflammatory lesions were noticed, possibly indicating the presence of a vesico-peritoneal fistula. Therefore, a direct radionuclide cystography was performed. The scintigraphic images single-photon emission computed tomography (SPECT/CT) showed a radioactive spot, indicative of a vesico-peritoneal fistula. The fistula was treated for three months by catheterisation of the urinary bladder. The follow-up SPECT-CT did not reveal any urine leakage from the bladder. The clinical symptoms disappeared as well.

Calculation of therapeutic activity of radioiodine in Graves' disease by means of Marinelli's formula, using technetium (99mTc) scintigraphy.

The therapeutic activity of 131I administered to patients with Graves' disease can be calculated by means of Marinelli's formula. The thyroidal iodine uptake (131IUmax) needed for the calculation is usually determined with the use of 131I. The purpose of the paper was to estimate 131IUmax on the basis of technetium uptake in the thyroid at 20 min (99mTcU20min). Eighty patients suffering from Graves' disease were qualified for radioiodine therapy with measurement of fT4, fT3, thyroid-stimulating hormone and its receptor (TRAb). Prior to the treatment, all the patients were euthyroid. 131IUmax for each patient was determined according to the levels of 131I after 24 h (131IU24h), while effective half-life (T eff) according to the measurements of 131IU24h and 131I uptake after 48 h (131IU48h). Additionally, on the day before measuring 131IU24h, 99mTcU20min was calculated for each patient. It was demonstrated that there existed a correlation, with statistical significance at p < 0.05, between the following pairs of values: TRAb and 131IU24h, TRAb and 99mTcU20min, and 99mTcU20min and 131IU24h. The interdependence between 131IU24h and 99mTcU20min at the level of significance p < 0.05 is described by the following algorithms: 131IU24h = 17.72 × ln (99mTcU20min) + 30.485, if TRAb < 10 IU/ml, and 131IU24h = 18.03 × ln (99mTcU20min) + 38.726, if TRAb > 10 IU/ml. It is possible to predict thyroid iodine uptake 131IU24h in Graves' disease on the basis of measuring the uptake of 99mTcU20min. This shortens the time necessary for diagnosis and enables the calculation of 131I activity using Marinelli's formula.

Single, very low dose (0.03 mg) of recombinant human thyrotropin (rhTSH) effectively increases radioiodine uptake in the I-131 treatment of large nontoxic multinodular goiter.

BACKGROUND: Radioiodine therapy (RIT) in patients with large nontoxic multinodular goiter (MNG) recently becomes more common method in comparison to surgery (especially in elderly patients and with contraindications because of severe chronic diseases other systems). Repeatedly low thyroid radioactive iodine uptake (RAIU) decreases effectiveness of RIT or makes it impossible. The recombinant human thyrotropin can increase RAIU and improve the results of RIT. THE AIM OF THE STUDY: was to assess the influence of a single very low dose (0.03 mg) of rhTSH on RAIU and thyroid function in euthyroid (MNG-EU) and subclinical hyperthyroid (MNG-SC) patients with a large multinodular goiter. MATERIAL AND METHODS: 40 patients (14 male, 26 female, age 57-80 yr) with large non-toxic MNG over 80 grams and with baseline RAIU < 40% were included into the double-blind randomized study and divided into two groups: rhTSH-group and control group. First group received the single intramuscular injection of 0.03 mg rhTSH and the second received placebo. The RAIU were measured 24 and 48 hours after the rhTSH and then all the patients were administered therapeutic doses of I-131. TSH and free thyroxine levels were measured at 1st and 2nd day after the injection of rhTSH and later, at 4 and 8 weeks after the RIT. RESULTS: The mean RAIU increased significantly from 30.44 ± 7.4% to 77.22 ± 8.7% (p < 0.001). There were no statistically significant differences in RAIU between euthyroid (MNG-EU) and subclinically hyperthyroid (MNG-SC) patients. The peak of serum TSH was noticed 24 hours after rhTSH injection and in MNG-EU patients it has remained within normal range, similarly as fT4. In the MNG-SC group the administration of rhTSH resulted in a significant increase in the TSH values after 24 hours, whose mean level slightly exceeded the upper limit of the normal range with normalization at 48 hours. 8 weeks after the RIT, the TSH and fT4 levels did not exceed the normal range and did not differ in a statistically significant way. CONCLUSIONS: Even the single very low dose of rhTSH increases the values of RAIU in significant way, in euthyroid and subclinically hyperthyroid patients. The administration of rhTSH is well-tolerated. Neoadjuvant administration of a low dose (0.03 mg) of rhTSH before I-131 seems to be an optimal method of management which may increase the effectiveness of RIT and decrease the exposure of the patients to absorbed doses of ionizing radiation.

Radioiodine therapy for Graves' disease - retrospective analysis of efficacy factors.

INTRODUCTION: Radioiodine ((131)I) isotope therapy is the method of choice in the treatment of Graves' disease relapse. The efficiency of this method is dependent on many factors; therefore, the present paper aims to identify the parameters that have a crucial impact on the efficacy of radioiodine therapy for Graves' disease. MATERIAL AND METHODS: The authors performed a retrospective analysis of the medical documentation of 700 Graves' disease sufferers treated with (131)I. The patients were divided into three groups depending on the thyroid-absorbed dose of (131)I: group I - 100 Gy, II - 150 Gy, and III - 200 Gy. The authors assessed the influence of gender, age, presence of orbitopathy, TRab titres, thyroid mass, iodine uptake after 24 and 48 hours, and the absorbed dose on the treatment efficacy at one year post-(131)I administration. RESULTS: The volume of thyroid gland (P < 0.002) and the thyroid-absorbed dose (P < 0.001) were the only factors that had a significant impact on the outcome of the treatment. The likelihood of hyperthyroidism persisting (odds ratio: 3.71, 95% confidence interval: 2.4-5.87) was greatest in patients from group I. In group II, with thyroid volume amounting both to 25 mL and to 25-50 mL, the percentage of hyperthyroidism was lowest (1 and 0%). However, with thyroid volume > 50 mL, the percentage of hyperthyroidism was lowest in group III (10%). CONCLUSIONS: The absorbed dose of (131)I and the volume of the thyroid gland are two parameters that have a significant influence on the efficacy of radioiodine therapy for Graves' disease. 150 Gy is the optimal dose for glands < 50 mL. A goitre > 50 mL requires an absorbed dose of 200 Gy in order to minimise the risk of recurrent hyperthyroidism.