Radioiodine Therapy For Thyroid Cancer Research Articles

Radioiodine Therapy for Thyroid Cancer and Hyperthyroidism in Patients with End-Stage Renal Disease on Hemodialysis

Treatment with radioactive iodine ((131)I) may be necessary for thyroid cancer or for hyperthyroidism in patients with end-stage renal disease who require hemodialysis. Because (131)I is cleared mainly by the kidneys in patients with normal renal function, many issues arise in patients who require (131)I treatment but who are on hemodialysis. This paper presents a case report of a patient on dialysis who required treatment with (131)I for thyroid cancer. We describe a mathematical model, which suggests that the treatment dose of (131)I for a patient with thyroid cancer on hemodialysis would be approximately 13%-28% of a typical empiric dose of (131)I for a patient with normal renal function. Also, we present a comprehensive review and discussion of the literature on patients who are receiving hemodialysis who were treated with (131)I for either thyroid cancer or hyperthyroidism. Using a multidisciplinary approach and special precautions, (131)I therapy can be administered safely and effectively for patients with thyroid cancer or hyperthyroidism who are receiving hemodialysis.

Prospective Single Arm Study of Radioprotection by Amifostine in High Dose Radioiodine Therapy for Thyroid Cancer

Purpose: Xerostomia, sialoadenitis, taste dysfunction and nausea are well known toxicities following high dose radioactive iodine (RAI) treatment for well-differentiated thyroid cancer. This prospective study sought to determine the incidence rates for RAI adverse effects and to determine, whether the radioprotector, amifostine could decrease the duration of the adverse effects in single treatment patients. Materials and methods: Patients with differentiated thyroid cancer received 150 mCi RAI after total thyroidectomy. All patients were pretreated with 1 mg granisetron and 4 mg dexamethasone. Patients in the amifostine arm (n = 27) were prospectively enrolled and received 500 mg amifostine subcutaneously. Adverse effects were scored based on the CTCAE at 1 month, 6 months, and yearly intervals using a physician administered questionnaire. The results were compared with a retrospective no amifostine cohort (n = 22) for whom data was collected with the identical questionnaire. Results: The overall incidence of xerostomia, sialadenitis, taste dysfunction and nausea in the treatment group was 26, 22, 52 and 26% respectively. Only grades 1 and 2 adverse effects were observed. The mean duration (days) of xerostomia (control vs treatment)—37.3 vs 21.9 (F test, p = 0.016), taste dysfunction—45.5 vs 23.5 (F test, p = 0.001), sialadenitis— 16.8 vs 7.5 and nausea—18.7 vs 5.1. Conclusion: In patients treated once with high dose RAI, who develop xerostomia, sialoadenitis, taste dysfunction, and/or nausea, the duration of symptoms appears to be reduced by pretreatment with 500 mg of subcutaneous amifostine without significant treatment related adverse effects.

Expression of the human sodium/iodide symporter (hNIS) in xenotransplanted human thyroid carcinoma.

The uptake of iodide in thyroid epithelial cells is mediated by the sodium/iodide symporter (NIS). The uptake of iodide is of vital importance for thyroid physiology and is a prerequisite for radioiodine therapy in thyroid cancer. Loss of iodide uptake due to diminished expression of the human NIS (hNIS) is frequently observed in metastasized thyroid cancer. So far, no animal model for the study of radioiodine therapy in thyroid cancer has been available. Strategies to restore iodide uptake in thyroid cancer include the exploration of hNIS gene transfer into hNIS defective thyroid cancer. We have performed a stable transfection of hNIS into the hNIS defective follicular thyroid carcinoma cell line FTC133. Stably transfected colonies exhibited high uptake of Na125I, which could be blocked completely with sodium perchlorate. hNIS transfected FTC133 and non-transfected cell lines injected subcutaneously in nude mice formed tumors after 6 weeks. Iodide uptake in the hNIS transfected tumor was much higher than in non-transfected tumor, but a rapid release of radioactivity from the hNIS transfected tumor was observed. Further studies are necessary to investigate the role of hNIS in relation to other thyroid specific proteins in iodide metabolism in thyroid cancer.

Reestablishment of in vitro and in vivo iodide uptake by transfection of the human sodium iodide symporter (hNIS) in a hNIS defective human thyroid carcinoma cell line.

Uptake of iodide is a prerequisite for radioiodine therapy in thyroid cancer. However, loss of iodide uptake is frequently observed in metastasized thyroid cancer, which may be explained by diminished expression of the human sodium iodide symporter (hNIS). Strategies to restore iodide uptake in thyroid cancer include the exploration of hNIS gene transfer into hNIS defective thyroid cancer. In this study, we report the stable transfection of a hNIS expression vector into the hNIS defective follicular thyroid carcinoma cell line FTC133. Stablely transfected colonies exhibited high uptake of Na125I, which could be blocked completely with sodiumperchlorate. hNIS mRNA expression corresponded with iodide uptake in semiquantitative polymerase chain reaction. Iodide uptake was maximal after 60 minutes, whereas iodide efflux was complete after 120 minutes. hNIS transfected FTC133 and control cell lines injected subcutaneously in nude mice formed tumors after 6 weeks. Iodide uptake in the hNIS transfected tumor was much higher than in the nontransfected tumor, which corresponded with hNIS mRNA expression in tumors.

Failure of TSH Rise Prior to Radio-Iodine Therapy for Thyroid Cancer: Implications for Treatment

We describe three patients with well-differentiated thyroid carcinoma in whom no rise in serum thyroid-stimulating hormone (TSH) was observed after the discontinuation of thyroid hormone. In one patient, TSH deficiency was due to panhypopituitarism secondary to the empty sella syndrome. This patient initially failed to respond to 131I but was subsequently given purified porcine TSH prior to further 131I therapy. This resulted in a significant fall in the thyroglobulin level. In two further patients, TSH levels were suppressed by functioning follicular thyroid cancer. There was an unexpectedly good 131I uptake by metastases and they responded clinically.The failure of TSH levels to rise after thyroid hormone withdrawal should prompt investigation of the pituitary-thyroid axis. In patients with hypopituitarism, exogenous TSH is recommended, to increase the 131I uptake. In contrast, when TSH is suppressed by functioning tumour, radio-iodine treatment may still be effective.

Minimal residual disease: a target for radioimmunotherapy with 131I-labeled monoclonal antibodies? Some dosimetric considerations.

Tumor size is one of the decisive parameters for the efficacy of conventional radiation therapy. From experimental and clinical data this seems also to be true for systemic radiotherapy, such as radioiodine therapy in thyroid cancer (Malone 1975) or radioimmunotherapy (RIT) with labeled monoclonal antibodies (MAbs) (Thedrez et al. 1989; Chatal et al. 1989) In general, it may be stated that the smaller the tumor size, the greater the chance of controlling it. However, for a very small tumor, the contrary may be the case in systemic radiotherapy: due to the limited range of the radionuclides used, a considerable proportion of the energy may be deposited outside the tumor and tumoricidal doses may not be achieved. Thus, in the situation of minimal residual disease (MRD) the chance of cure may be lessened.KeywordsDose DistributionMinimal Residual DiseaseRadioiodine TherapySphere CenterTumor SphereThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Radioiodine Therapy for Thyroid Cancer

A small abut important subset of patients with differentiated thyroid cancer will die of disease. Our approach to therapy treats almost all patients similarly, with aggressive surgery and I-131 therapy. Meticulous follow-up should include multiple I-131 diagnostic scans using at least 5 to 10 mCi of I-131 with attention to proper patient preparation and good quality procedures. Thyroglobulin levels should be monitored, and other radiographic diagnostic procedures, including thallium scans and MR imaging, should be used as needed. Until screening tests are discovered which will accurately pinpoint patients at high risk for aggressive, recurrent thyroid cancer, the best course of action appears to be aggressive management, including radioiodine therapy.

Retrospective evaluation of the dose received by the ovary after radioactive iodine therapy for thyroid cancer

In an earlier study, we evaluated the frequency of clinical manifestations of ovarian insufficiency after radioiodine therapy for thyroid cancer. We were thus led to consider the dose received by the ovary (DRO) during these treatments. In the literature, this dose is expressed as a function of the activity administered. However, in our study, the disorders were not correlated with the activity administered. Faced with this discrepancy, we have attempted to establish a dosimetric model using the parameters available for each patient. The results obtained show that besides the activity administered, which plays a role, morphological and kinetic factors specific to each individual have an importance that cannot be ignored when addressing this problem.

Nuklearmedizin in Deutschland

The development of nuclear medicine in Germany from early approaches with 32P and 1311 to the first radioiodine therapy of thyroid cancer up to the clarification of basic principles for current thyroid diagnostics and for functional scintigraphic imaging are presented. Selected references are used in portraying scientific stepping stones of our speciality as well as its establishment in clinical practice during the first two decades. Researchers, places, and facts are specified and interpreted in their relation to the state-of-the-art of nuclear medicine.

Relation between effective radiation dose and outcome of radioiodine therapy for thyroid cancer.

We used a combination of radioiodine scanning and quantitative radiation dosimetry to evaluate responses to therapeutic irradiation with 131I in 76 patients with thyroid adenocarcinoma. Fifty patients received 131I treatment for ablation of residual thyroid tissue after surgical thyroidectomy, and 26 had 131I treatment for metastatic thyroid cancer. Successful ablation was observed in patients receiving higher radiation doses to the thyroid--about 4.4 times those in patients whose lesions were not ablated--largely because of a longer effective half-life of 131I in residual thyroid tissue in the patients with ablated lesions. Patients with metastases that persisted after 131I therapy tended to have more advanced disease and received significantly lower radiation doses per millicurie of administered 131I than did persons whose lesions responded to treatment. Initial 131I treatment resulting in radiation doses of at least 30,000 rad to thyroid remnants and 8000 rad to metastases was associated with a significant increase in the rate of response to therapy.

Radioiodine therapy of thyroid cancer

Radioiodine uptake has been found to develop in over 50%, and probably in about 80%, of all adenocarcinomas of the thyroid, provided that tests are made at times up to 4 mo or more after total ablation of all normal thyroid tissue. In tumors that have been shown by biopsy to be predominantly or solely papillary in structure, efficient uptake and response to radioiodine therapy occur about as commonly as in those that are mainly or entirely follicular; uptake also develops often in tumors in which colloid is not demonstrable. Hurthle cell carcinomas rarely concentrate radioiodine efficiently or respond to this type of therapy. Once uptake has developed, effective treatment of a disseminated tumor usually requires from three to seven therapeutic doses of 150 mCi of 131 I each, given over the course of 2 to 5 yr, before all clinical and counting evidence of remaining tumor tissue is abolished. During the course of this treatment, the progress of tumor destruction can be ascertained by quantitative indications of the amount of remaining tumor activity. A simple and comprehensive measure is obtained from the plasma concentration of protein-bound radioiodine as determined at 6 days after each dose. This value is ordinarily found to fall progressively during the course of effective treatment, and it probably parallels the remaining amount of functioning tumor tissue at the time of each dose. If normal thyroid tissue has been ablated, remaining tumor activity is likely if the value exceeds 0.006%/liter, and certainly if it exceeds 0.010%/liter, but is unlikely with values below 0.003%/liter. Radioiodine treatment may fail because of continuing spread or other complications from existing metastases even if efficient uptake develops, or, occasionally, through development of anaplastic change in the tumor, marrow aplasia, or leukemia. However, radioiodine therapy appears to be effective in destroying disseminated tumors in about half of all patients treated.

Leukaemia after I 131 therapy for thyroid cancer

Summary A new case of leukaemia following radioiodine therapy for thyroid cancer is recorded. The patient received a total of only 400 mCs. of I131. Two years elapsed between the administration of the initial dose and the onset of symptoms. If leukaemia following doses of this order is reported more often in the future, it is suggested that radioiodine should not be the first method of treatment advised for metastatic deposits from a well differentiated, alveolar adenocarcinoma of the thyroid. Some of these tumours are of extremely low grade malignancy, and it is probable that long term remissions can be induced in many patients with suppressive doses of thyroid, thyroxine, or triiodo-thyronine. There is no reason why this form of therapy should reduce the chances of a response to radioiodine treatment at a later date.