[Radioactive iodine tests in diagnosis of thyroid diseases].
Explore the source record for details and available documents.
SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
There is a need to provide realistic estimates of the activity discharged to the drains by patients undergoing procedures involving unsealed radionuclides. These estimates are essential for record keeping purposes, to demonstrate compliance with limits set in waste disposal authorizations and for planning new installations. In this study, we report the discharge of activity for 174 patients (202 treatments) undergoing treatment of thyroid carcinoma with radioactive iodine. We have found that approximately 55% of administered activity is excreted in the first 24 h and that 85% of administered activity is discharged to the sewer over a typical inpatient stay of 5 days. There was no significant difference in levels of discharge between those patients undergoing inaugural ablation therapy and those having further treatments with radioactive iodine.
OBJECTIVE: Antithyroidal drugs (ATD) are used in the management of Graves' disease either as primary therapy for several months while awaiting remission of the disease or as pretreatment for several weeks prior to definitive radioactive iodine therapy (RAI). We have reported previously that pretreatment with propylthiouracil (PTU) before definitive RAI therapy is associated with a higher RAI treatment failure rate than RAI therapy alone. The objectives of the current study were 2-fold. First, to verify the results of our prior study regarding the effect of PTU used as pretreatment before RAI in a cohort of patients from a different institution and, secondly, to better define the relationship between the number of days off PTU before RAI therapy and therapeutic efficacy of RAI dosing. DESIGN: A retrospective review of Graves' disease patients treated from 1980 to 1994. PATIENTS: Study patients had to meet the following inclusion criteria: radionuclide studies and thyroid hormone values consistent with Graves' disease, at least 1 year of follow-up data available and discontinuation of the ATD at least 4 days before RAI administration. Exclusion criteria included therapy with any ATD other than PTU or ATD therapy during or following RAI dosing. MEASUREMENTS: Effectiveness of RAI therapy, days on PTU, days off PTU and calculated RAI dose to the thyroid were recorded for each subject. We compared the efficacy of RAI therapy in patients treated with PTU (used either as pretreatment in preparation for RAI therapy or as primary long-term therapy) before RAI administrations to those treated with RAI alone with special attention to the number of days on and off PTU before RAI dosing. Patients were considered RAI treatment failures if a second dose of RAI was required to achieve a euthyroid or hypothyroid state. RESULTS: One hundred and sixteen patients met our study criteria. Forty patients received PTU therapy for a mean of 221 +/- 59 days. The PTU was discontinued for a mean of 60 +/- 25 days before RAI dosing. Persistent hyperthyroidism was seen in 9% (7/76) of patients treated with RAI alone. The failure rate of a single dose of radioactive iodine was significantly increased when PTU was discontinued between 4 and 7 days before the administration of RAI (29% vs 9% for RAI alone, P = 0.039). PTU discontinued for at least 1 week before RAI dosing was associated with a nearly 2-fold increase in failure rate, but this difference did not achieve significance (17% vs 9% for RAI alone, P = 0.24). Examining only those patients receiving PTU, patients who had successful single dose RAI therapy tended to receive a higher dose of RAI than patients failing RAI therapy (480 +/- 30 vs 410 +/- 40 MBq administered dose, P = 0.18; and 8.0 +/- 0.9 vs 5.5 +/- 1.1 MBq/g thyroid tissue calculated dose, P = 0.21). Furthermore, total serum thyroxine at diagnosis was significantly higher in patients failing RAI therapy after PTU administration than in patients successfully treated with RAI after receiving PTU (316 +/- 40 vs 225 +/- 13 nmol/L, P = 0.03). CONCLUSIONS: Propylthiouracil discontinued 4-7 days before radioiodine dosing is associated with a significant increase in the failure rate of a single dose of radioiodine. Discontinuation of the propylthiouracil for at least a week before radioiodine administration is associated with a higher, although not statistically significant, radioiodine failure rate. In patients that require treatment with propylthiouracil before radioiodine therapy, a higher total serum thyroxine level at diagnosis is associated with an increased rate of radioiodine failure. Consideration should be given to increasing empirically the dose of radioiodine administered to Graves' disease patients that have received propylthiouracil within a week of radioiodine administration in an effort to decrease the radioiodine failure rate to an acceptable level.
Although the causal relation between radioactive iodine therapy (RIT) for Graves' disease and the subsequent occurrence of thyroid carcinoma is not definite, surgeons may be faced with the treatment of such patients. We studied the clinicopathologic features of patients with thyroid carcinoma following RIT for Graves' disease. From January 1983 to December 1991, 11 patients with thyroid carcinoma occurring 1 year or more after RIT for Graves' disease underwent surgery at Ito Hospital. These 11 patients accounted for 0.51% of 2146 surgical cases of thyroid carcinoma and 0.17% of 6419 RIT cases of Graves' disease during the period. They were all women, and their mean ages at RIT and surgery were 44.3 and 51.4 years, respectively. The administered dose of RI was 222.1 MBq and the absorbed dose 45.3 Gy on average. Total thyroidectomy was performed in two patients, subtotal thyroidectomy in three, and lobectomy in six. Bilateral modified neck dissection (MND) was added in two patients, and ipsilateral MND in seven. Histology revealed 10 papillary and 1 follicular carcinoma. The mean diameter of the tumor was 18.5 mm. Intraglandular dissemination of the tumor was noted in only one case and solid growth pattern in two. Nodal metastasis was disclosed in six cases, but in five of them only one node was involved. The present study indicated that thyroid carcinoma occurring after RIT for Graves' disease is not an aggressive variety, and thyroid lobectomy with ipsilateral MND would be sufficient as surgical treatment for such patients.
The development of hyperparathyroidism after radioactive iodine (RAI) therapy has been reported in 38 cases in the literature. However, the development of a parathyroid adenoma after RAI therapy for a hyperfunctioning multinodular goiter has not been reported. This report describes the pathologic and operative finding on a patient with both hyperthyroidism and hyperparathyroidism, which was diagnosed after previous RAI therapy for a toxic, multinodular goiter.
OBJECTIVE: Because in recent years the practice of TSH suppression has changed, and thyroxine doses have been reduced significantly in the treatment of patients with low-risk differentiated thyroid cancer, the goal of this study was to determine the time needed to attain a target TSH level (of 30 mIU/l) following levothyroxine withdrawal in patients treated with thyroxine according to current guidelines, in anticipation of radioactive iodine (RAI) administration. DESIGN: Observational study. PATIENTS: Thirteen consecutive patients with differentiated thyroid cancer on suppressive doses of levothyroxine planned for RAI administration. Five of the patients received cholestyramine in an attempt to facilitate TSH recovery. MEASUREMENTS: Serum TSH, free-T3 and free-T4, at 3-4-day intervals. RESULTS: In 13 patients on suppressive doses of thyroxine, on 15 separate occasions, baseline TSH levels were between 0.01 and 0.4 mIU/l. The mean interval required to reach the target TSH concentration of at least 30 mIU/l was 17 days (95% CI 15-19; range 11-28 days). Cholestyramine had no effect on the rate of TSH recovery. Once TSH concentration became detectable, it increased exponentially; and once it reached the upper limit of normal, it rarely took more than 10 days to attain target level. CONCLUSIONS: Attaining target TSH level before radioactive iodine administration requires a considerably shorter time than is currently recommended. Reducing preparation time might improve patients' acceptance of the procedure.
A case of radiation myelopathy after radioactive iodine therapy is reported. This is the first report to describe radiation myelopathy after I-131 therapy. A 62-year-old female with spinal metastasis of T10 received I-131 therapy. She presented with radiation myelopathy 34 months after the irradiation. We need to recognize the possibility of this serious complication even in the case of I-131 therapy. There is a risk of radiation myelopathy even after I-131 therapy, especially in cases with spinal cord compression such as this.
We describe a patient with transient thyrotoxicosis and low radioactive iodine uptake by the thyroid. Although the clinical course in this patient was compatible with subacute thyroiditis, she did not experience pain or tenderness in the neck. The use of thyroid hormones or iodine was excluded. The substantial level of thyroid antibody in serum was present during the entire phase of the disease. Histological findings on thyroid biopsy were characteristic of chronic lymphocytic thyroiditis. Furthermore, it was remarkable that the histological abnormalities improved spontaneously during the course of several months, with the spontaneous recovery of clinical signs and biochemical abnormalities.
To determine whether a therapeutic dose of iodine 131 affects the results of 24-hour radioactive iodine uptake (RAIU) testing, we reviewed records of hyperthyroid patients previously treated with 131I at Michigan State University and its affiliated hospitals. We identified 26 patients who had had clinical evaluation and determination of the serum thyroxine (T4) level, triiodothyronine resin uptake (T3RU), and RAIU (using 131I) within two weeks before and several months after the therapeutic dose of 131I. Before treatment, all patients had clinical hyperthyroidism, with an elevated T4 level and increased T3RU and RAIU. After treatment with 131I, eight patients (31%) had an RAIU that was discordant with their clinical and biochemical (T4 and T3RU) assessment. In six patients (23%) of the RAIU was inappropriately high, and in two patients (8%) it was inappropriately low. Since we did not identify any other factors known to interfere with the results of RAIU testing, we conclude that a therapeutic dose of 131I, may by itself increase or decrease a subsequent RAIU determination; therefore, after treatment with 131I, RAIU is not a good diagnostic index of thyroid activity.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Radioactive iodine (131I) was used in the treatment of a 12-year-old female dog with hyperthyroidism resulting from a large, unresectable (and metastatic) thyroid carcinoma associated with signs of severe inspiratory stridor and dyspnea. Hyperthyroidism was diagnosed on the basis of clinical signs (polyuria, polydipsia, polyphagia, weight loss, nervousness) and high basal serum thyroxine (T4) concentrations, as well as thyroid radioiodine kinetic studies that showed a high radioiodine uptake into the thyroid (% thyroid uptake) and markedly increased serum concentrations of protein-bound iodine-131 (PB131I) after 131I tracer injection. Thyroid imaging revealed diffuse radionuclide accumulation by the tumor, which involved both thyroid lobes. The dog was treated with three large doses of radioiodine (131I), ranging from 60 to 75 mCi, given at intervals of 5 to 7 months. The dog became euthyroid, and the size of the tumor decreased by approximately 25% after each 131I treatment, improving the severe inspiratory stridor and dyspnea, but both the hyperthyroid state and breathing difficulty recurred within a few months of each treatment. The dog was euthanatized 5 months after the last treatment because of progressive tracheal compression and pulmonary metastasis.
Chemical forms of radioactive iodine and its effects upon marine organisms were studied by the tracer experiments. Seaweeds or fish were held in the aquarium in which the 125I tracer in either iodide or iodate form was inoculated. Iodide form of 125I was taken by Dorome (Chasmichthys gulosus) with the concentration factor of about 10 and excreted with the biological half-life of 15 days, while iodate form of 125I was not taken up appreciably and the concentration factor did not greatly exceed unity. Uptake and loss of 125I were studied as well for 3 species of seaweeds, Hijiki(Hizikia fusiforme), Nejimoku (Sargassum sagamianum) and Tsunomata (Chondrus ocellatus). Iodate form of 125I was accumulated less than iodide form by these seaweeds but the concentration factor of iodate by these seaweeds was very high compared to those by fish.
In order to simply and safely treat radioactive iodine waste, a study of the removal of iodide ion from radioactive waste using electrodialysis with an anion exchange paper membrane, in which trimethylhydroxylpropylammonium groups were homogeneously dispersed with high density. In Na125I and Na36Cl concentration-cell system, electric ion and water conductances, phenomenological coefficients, have been experimentally determined on basis of nonequilibrium thermodynamics. Prepared paper membrane had higher permselectivity of 125I ion than 36Cl ions by approximately 21%. On the other hand, water flux that was accompanied by an ionic transference in prepared paper membrane was greatly larger than that in typical synthesized membrane. It is suggested that a depression of water mobility is important to practice an ideal radioactive iodide waste electrodialysis system with a novel anion exchange paper membrane.
In a series of 156 thyrotoxic patients treated with low doses of radioactive iodine the therapeutic dose was calculated by means of a sliding scale in which the dose level was varied according to the estimated size of the gland. Of the patients so treated 56.5% achieved a remission with a single dose of (131)I. The incidence of hypothyroidism at one year was 5%.
It is shown that radioactive iodine therapy is an alternative method in the treatment even of large goitres provided this method of treatment is confined to patients beyond the age of 40. If the patient is generally inoperable, this is in fact the method of choice. The success rate can be compared with that of other methods of treatment. In this connection, special attention is drawn to the high rate of alleviation of complaints. No significant side effects are seen; in a few cases only, treatment will have to be repeated.
Steroids labeled with radioactive isotopes are useful tracers for radio-immunoassay and for in vivo nuclear medecine purposes. We here report and discuss methods for direct labeling of the steroids estriol, estradiol, and progesterone with radioiodine-125 or -131. The purification procedure and some chemical and physical properties of the purified labeled materials are referred to and discussed.
Explore the source record for details and available documents.