[CME: Radioactive iodine therapy in thyroid cancer]. / CME: Radiojodbehandlung des Schilddrüsenkarzinoms.

Differentiated thyroid carcinomas represent about 90% of all thyroid tumors and are divided in papillary and follicular carcinomas. Their prognosis is good, however, recurrences are not rare. Their ability to accumulate iodine is used for the radioactive iodine treatment. The aim of the postoperative radioactive iodine ablation therapy is the complete elimination of remnant thyroid cells and sensitive staging (Fig. 1). The recurrence rate decreases after a complete thyroid ablation. Furthermore, thyroglobulin can be used as a sensitive tumor marker. Radioactive iodine treatment by itself describes the therapy of metastases. An exception is the papillary microcarcinoma, which in general is treated by a lobectomy alone.

Cerebral metastases from thyroid carcinoma: complete remission following radioiodine treatment.

BACKGROUND: Brain metastases arise in roughly 0.9% of all cases of differentiated thyroid cancer. The median survival of adult patients with thyroid carcinoma that has metastasized to the brain is less than one year. Radioactive iodine treatment is only rarely given because its efficacy is not documented. In children, the situation may be different. METHOD: In 2005, a 15-year-old girl underwent thyroidectomy, and an oxyphilic variant of papillary thyroid carcinoma was found in ectopic thyroid tissue. The patient underwent oral, high-dose radioactive iodine treatment. The post-therapeutic I-131 whole-body scan revealed multiple metastases in the skeleton, lungs, and the soft tissues, along with physiological uptake of the residual thyroid tissue. Magnetic resonance imaging of the head revealed two brain metastases. RESULTS: When the initial treatment was completed, additional age-adapted high-dose radioactive iodine treatment was given, up to a total activity level of 35 GBq. There followed a complete remission of all metastases in the brain, bones, lungs, and soft tissues. Computed tomography of the chest revealed stable residuals. Over the ensuing 7.5 years of follow-up, the thyroglobulin values steadily declined to less than 2 ng/mL. The patient was asymptomatic at her last follow-up in May 2013. She did not develop any delayed reaction to high-dose radioactive iodine treatment (in particular, she did not develop leukemia or any other secondary malignancy). She remained fertile: after completion of the treatment, she had two healthy children. CONCLUSION: In this patient with multifocal thyroid carcinoma, a rare entity, radioactive iodine treatment was successful as the single treatment. This case illustrates the point that a given therapeutic modality might succeed in an individual case despite a total or near-total lack of efficacy for most patients in the same situation.

Randomized controlled trial of a computerized decision aid on adjuvant radioactive iodine treatment for patients with early-stage papillary thyroid cancer.

PURPOSE: Decision-making on adjuvant radioactive iodine (RAI) treatment for early-stage papillary thyroid cancer (PTC) is complex because of uncertainties in medical evidence. Using a parallel, two-arm, randomized, controlled trial design, we examined the impact of a patient-directed computerized decision aid (DA) on the medical knowledge and decisional conflict in patients with early-stage PTC considering the choice of being treated with adjuvant RAI or not. The DA describes the rationale, possible risks and benefits, and the medical evidence uncertainty relating to the choice. PATIENTS AND METHODS: We recruited 74 patients with early-stage PTC after thyroidectomy. Participants were assigned by using 1:1 central computerized randomization to either the DA group with usual care (intervention) or usual care alone (control). Medical knowledge about PTC and RAI treatment (the primary outcome), as well as decisional conflict (a secondary outcome), were measured by using validated questionnaires, and the respective scores were compared between groups. RESULTS: Consistent with PTC epidemiology, 83.8% (62 of 74) of the participants were women, and the mean age was 45.8 years (range, 19 to 79 years). Medical knowledge about PTC and RAI treatment was significantly greater and decisional conflict was significantly reduced in the DA group compared with the control group (respective P values < .001). The use of adjuvant RAI treatment was not significantly different between groups (DA group, 11 of 37 [29.7%]; controls, seven of 37 [18.9%]; P = .278). CONCLUSION: A computerized DA improves informed decision making in patients with early-stage PTC who are considering adjuvant RAI treatment. DAs are useful for patients facing decisions subject to medical evidence uncertainty.

Persistent disease in patients with papillary thyroid carcinoma and lymph node metastases after surgery and iodine-131 ablation.

AIM: The aim of this study was to assess the efficacy of treatment of patients with papillary thyroid carcinoma (PTC) and lymph node metastases at the time of diagnosis and its influence on the course of the disease. METHODS: It is a retrospective review of all 51 patients with PTC and histologically proven lymph node metastases treated with I-131 ablation in our center between January 1990 and January 2003. Patients were considered disease-free if during follow-up thyroglobulin levels were undetectable and scintigraphy with 370 MBq (131)I was negative during thyroid-stimulating hormone stimulation. Staging of patients was in accordance with the 5th edition of the TNM system. RESULTS: After a median follow-up of 84 months, 33 (65%) patients were never free of detectable disease; and 3 of these patients had died of the PTC. In total, 22 patients still showed persistent activity in the neck outside the thyroid bed, which was suspect to be cervical lymph node metastasis on postablation scintigraphy; it was not related to the initial clinical presentation (lymph node metastasis or a thyroid nodule without suspicion of metastatic disease) or to the extent of surgery. Altogether, 34 patients required additional treatment. Patients presenting with clinically overt lymph node metastasis showed a significantly (p = 0.022) lower rate of becoming disease-free than those in whom microscopic lymph node involvement was unexpectedly found upon pathologic examination. There was no significant association of the eventual outcome with the extent of surgical treatment, TNM staging, or age. CONCLUSIONS: Patients with lymph node metastasis are considerably less likely to become disease-free. If the initial treatment does not result in a disease-free status, chances are low that additional treatment will succeed in achieving it.

Cost savings of patients with a MACIS score lower than 6 when radioactive iodine is not given.

OBJECTIVE: To assess the cost savings if the current policy of treating patients with a MACIS (metastases, age, completeness of resection, invasion, and size) score lower than 6 using radioactive iodine (RAI) was changed to reflect the findings of recent studies. DESIGN: Retrospective medical record review. SETTING: Mount Sinai Hospital, Toronto, Ontario. PATIENTS: Between January 1, 2002, and July 1, 2005, 199 consecutive patients with a MACIS score lower than 6 who received RAI treatment after total thyroidectomy. MAIN OUTCOME MEASURES: Patient demographics were analyzed. Costs for the dose of RAI, hospital stay, and health insurance claims were included in the calculations. RESULTS: For 199 consecutive patients, the cost for sodium iodide 131 treatment totaled Can$161 588, and the required 2-day stay in isolation totaled Can$764 558. The overall cost to the health care system was Can$934 106, which translates into approximately Can$4694 per patient. CONCLUSIONS: By following the recommendations of recent evidence-based studies and by ceasing to treat patients with a MACIS score lower than 6 after total thyroidectomy using RAI, cost savings can be accrued for health care systems involved in the treatment of thyroid cancer. Alternate strategies, such as treating patients who need RAI therapy on an outpatient basis and reducing the dose of RAI, can lower costs as well.

Total thyroidectomy and adjuvant radioiodine treatment independently decrease locoregional recurrence risk in childhood and adolescent differentiated thyroid cancer.

UNLABELLED: We sought to assess whether extensive surgical treatment, postsurgical radioiodine therapy, or both decrease the risk of locoregional recurrence (LR) after curative primary treatment in children and adolescents diagnosed with differentiated thyroid cancer (DTC) at age

Tumour dosimetry and response in patients with metastatic differentiated thyroid cancer using recombinant human thyrotropin before radioiodine therapy.

The development of recombinant human thyrotropin (rhTSH) has given clinicians new options for diagnostic follow-up and treatment of patients with differentiated thyroid cancer (DTC). This paper evaluates the tumour dosimetry and response following -iodine-131 treatment of metastatic thyroid cancer patients after rhTSH stimulation instead of classical hormone withdrawal-induced hypothyroidism. Nineteen consecutive (131)I treatments in 16 patients were performed after rhTSH stimulation. All patients had undergone a near-total thyroidectomy followed by an ablative dosage of (131)I. They all suffered from metastatic or recurrent disease showing tumoral (131)I uptake on previous post-treatment scintigraphy. Dosimetric calculations were performed using (131)I tumour uptake measurements from post-treatment (131)I scintigrams and tumour volume estimations from radiological images. Response was assessed by comparing pre-treatment serum thyroglobulin (Tg) level with the Tg level 3 months post treatment. In 18 out of 19 treatments, uptake of (131)I in metastatic or recurrent lesions was seen. The median tumour radiation dose was 26.3 Gy (range 1.3-368 Gy), and the median effective half-life was 2.7 days (range 0.5-6.5 days). Eleven of 19 treatments (10/16 patients) were evaluable for response after 3 months. (131)I therapy with rhTSH resulted in a biochemical partial response in 3/11 or 27% of treatments (two patients), biochemical stable disease in 2/11 or 18% of treatments and biochemical progressive disease in 6/11 or 55% of treatments. Our study showed that although tumour doses in DTC patients treated with (131)I after rhTSH were highly variable, 45% of treatments led to disease stabilisation or partial remission when using rhTSH in conjunction with (131)I therapy, without serious side-effects and with minimal impact on quality of life. RhTSH is therefore adequately satisfactory as an adjuvant tool in therapeutic settings and is especially suitable in advanced recurrent or metastatic DTC patients who may be intolerant to TSH stimulation by levothyroxine withdrawal.

Scintigraphic evaluation of salivary gland dysfunction in patients with thyroid cancer after radioiodine treatment.

PURPOSE: Sialadenitis is a well-recognized adverse effect of high-dose radioactive iodine treatment. This study was undertaken to determine whether Tc-99m pertechnetate salivary gland scintigraphy may be used for objective assessment of salivary gland function in patients with thyroid cancer treated with I-131. PATIENTS AND METHODS: The study group consisted of 71 patients (16 men, 55 women) with a mean age of 44 years (range, 16 to 73 years). Twenty-six (37%) patients were not given any radioiodine, and 18, 16, and 11 patients received doses of 100, 150, or 200 mCi (or higher), respectively. Parotid and submandibular glands were evaluated based on a four-grade scoring system. Correlation between the type of surgery, administered dose, time since therapy, subjective symptoms, and findings of salivary gland scintigraphy were evaluated. RESULTS: Subjective symptoms were questioned in 39 of the 45 patients who received radioactive iodine treatment. Fifty-four percent (21 of 39) of the patients reported xerostomia, of whom 86% (18 of 21) showed salivary gland dysfunction. Objective salivary gland dysfunction was observed in 69% (31 of 45) of patients. In 81% of the patients, the parotid glands were affected; in 13% of the patients, the submandibular glands were affected; and in 6%, both were affected ( < 0.000001). The frequency of salivary gland dysfunction showed a dose dependence to cumulative activity ( = 0.007). A greater complication rate was observed in patients with total thyroidectomy compared with subtotal surgery, although the correlation was not significant ( = 0.625). CONCLUSIONS: Parenchymal damage to the salivary glands induced by radioactive iodine treatment can be evaluated by salivary gland scintigraphy. The impairment is worse in the parotid glands and increases with the total dose.

Thyroid carcinoma in children and adolescents.

UNLABELLED: A clinical and pathological study was undertaken to define the prevalence, clinical presentation and outcome of thyroid carcinoma in children and adolescents. Clinical records from 48 patients under 20 years of age at diagnosis, out of 372 patients with thyroid cancer examined between 1980 and 1994, were retrospectively reviewed. Female/male ratio was 3.8/1. None had a previous positive history of head and neck irradiation. Patients underwent near-total (44 patients) or partial (4 patients) thyroidectomy followed by 131I ablation of residual thyroid tissue. The mean follow up period was 58.4 months, ranging between 2 and 190 months. Clinically a thyroid mass was present in 41 patients, 28 of whom also showed neck lymph node involvement. Node metastases were present in 50% of the patients and lung metastases in 4.2%. Histological type was papillary in 41, follicular in 6, and medullary in 1 case. Surgical complications were observed in 19 patients (40%). In 3 patients papillary thyroid cancer was associated with chronic lymphocytic thyroiditis. All patients were treated with 1-thyroxine suppressive therapy. Recurrences of cancer after surgical and radio-iodine treatment was observed only in one patient 8 months after surgery. CONCLUSION: Our experience demonstrates that thyroid carcinoma in childhood cannot be considered a rare occurrence, since it represents about 13% of all thyroid cancers, and is frequently associated with lymph node but rarely with distant metastases. Nevertheless, the prognosis of thyroid carcinoma in childhood is fairly good.

Tumoricidal cytokines enhance radioiodine uptake in cultured thyroid cancer cells.

UNLABELLED: We explored whether the stimulation of iodine uptake by interferons seen in rat thyroid cell line is reproducible in human thyroid cancer and thus applicable to enhance the efficacy of radioiodine therapy. METHODS: Surgical specimens from 12 papillary and 2 follicular adenocarcinomas were minced and seeded in culture trays. After 14-16 days in a medium supplemented with 5% calf serum, we measured cellular uptake of 125I during a 40-min incubation period. RESULTS: In 8 of 12 papillary and all 2 follicular carcinomas, interferon-gamma significantly stimulated iodine incorporation. The four nonresponder tumors had lower basal iodine uptake and relatively less differentiation of histologic features. The effect was dose dependent (0-100 U/ml), and the average maximum increase in responding cases was 35.1% over basal values. Tumor necrosis factor-alpha alone did not alter uptake, but at 300 U/ml it further enhanced the effect of interferon-gamma in the two follicular tumors. In addition to the pure cytokines, supernatant from lymphocyte culture conditioned with a bacterial immunostimulator also boosted radioiodine trapping in thyroid cancer cells. CONCLUSION: These in vitro results warrant animal experiments to test potential usefulness of tumoricidal cytokines in radioiodine therapy.

[Is total thyroidectomy and lymph node excision as therapy of differentiated thyroid gland carcinomas in childhood justified?]. / Ist die totale Thyreoidektomie und Lymphknotendissektion zur Therapie differenzierter Schilddrüsenkarzinome im Kindesalter angezeigt?

The extent of radical resection of differentiated thyroid carcinomas in children (< 18 years) is discussed controversially because of good prognosis, on the one hand, but a high rate of lymph node metastases, greater tumor size, lung metastases and tumor recurrences on the other. Because of our data we advocate thyroidectomy, cervical lymph node dissection and postoperative 131J-therapy as the treatment of choice in patients with manifest disease in order of further detection and/or treatment of lung metastases. Limited radicality (i.e. hemithyroidectomy) should be reserved for children with small and occult tumors.