Thyroidectomy without Radioiodine in Patients with Low-Risk Thyroid Cancer.

BACKGROUND: In patients with low-risk differentiated thyroid cancer undergoing thyroidectomy, the postoperative administration of radioiodine (iodine-131) is controversial in the absence of demonstrated benefits. METHODS: In this prospective, randomized, phase 3 trial, we assigned patients with low-risk differentiated thyroid cancer who were undergoing thyroidectomy to receive ablation with postoperative administration of radioiodine (1.1 GBq) after injections of recombinant human thyrotropin (radioiodine group) or to receive no postoperative radioiodine (no-radioiodine group). The primary objective was to assess whether no radioiodine therapy was noninferior to radioiodine therapy with respect to the absence of a composite end point that included functional, structural, and biologic abnormalities at 3 years. Noninferiority was defined as a between-group difference of less than 5 percentage points in the percentage of patients who did not have events that included the presence of abnormal foci of radioiodine uptake on whole-body scanning that required subsequent treatment (in the radioiodine group only), abnormal findings on neck ultrasonography, or elevated levels of thyroglobulin or thyroglobulin antibodies. Secondary end points included prognostic factors for events and molecular characterization. RESULTS: Among 730 patients who could be evaluated 3 years after randomization, the percentage of patients without an event was 95.6% (95% confidence interval [CI], 93.0 to 97.5) in the no-radioiodine group and 95.9% (95% CI, 93.3 to 97.7) in the radioiodine group, a difference of -0.3 percentage points (two-sided 90% CI, -2.7 to 2.2), a result that met the noninferiority criteria. Events consisted of structural or functional abnormalities in 8 patients and biologic abnormalities in 23 patients with 25 events. Events were more frequent in patients with a postoperative serum thyroglobulin level of more than 1 ng per milliliter during thyroid hormone treatment. Molecular alterations were similar in patients with or without an event. No treatment-related adverse events were reported. CONCLUSIONS: In patients with low-risk thyroid cancer undergoing thyroidectomy, a follow-up strategy that did not involve the use of radioiodine was noninferior to an ablation strategy with radioiodine regarding the occurrence of functional, structural, and biologic events at 3 years. (Funded by the French National Cancer Institute; ESTIMABL2 ClinicalTrials.gov number, NCT01837745.).

Clinical outcomes 1 year after empiric 131I therapy for hyperthyroid disorders: real life experience and predictive factors of functional response.

Radioiodine is a therapeutic option in Europe for Graves' disease (GD) and toxic multinodular goiter (MNG). PURPOSE: To compare empiric and calculated I activities using 2013 EANM recommendations. To look for predictive factors of therapeutic response to an empiric activity of I. To assess clinical situations favoring calculated treatment modalities. PATIENTS AND METHODS: Prospective monocentric study of clinical outcomes at 1 year follow-up in 86 patients with GD and MNG who received empiric I therapeutic activities (348-939 MBq). Differences between empiric and calculated activities were confronted to clinical outcomes. Physicians were not aware of the calculated activity at the time of prescription. RESULTS: One year after treatment, 9% (5/57) of GD patients and 7% (2/29) of MNG patients were still in a hyperthyroid state. Thyroid volume was reduced by 67% for GD and by 50% for MNG. In GD, empiric I activities were higher than calculated ones (564±131 vs. 316±319 MBq, P<0.001) in 93% (53/57) of patients. Pretherapeutic thyroid volume (>26 ml for GD; >40 ml for MNG) was associated with persistent hyperthyroidism. CONCLUSION: Empirically administered I for GD and MNG was associated with very high efficacy in thyroid function control and no side effects. Thyroid volume reduction did not preclude treatment efficacy. Activity calculation could be a useful method for treating patients with GD and thyroid volumes higher than 26 ml or patients with MNG and thyroid volumes higher than 40 ml. A selective approach based on pretherapeutic thyroid volume and radioiodine biokinetics might improve treatment success.

Quality of Life and Cost-Effectiveness Assessment of Radioiodine Ablation Strategies in Patients With Thyroid Cancer: Results From the Randomized Phase III ESTIMABL Trial.

PURPOSE: In the ESTIMABL phase III trial, the thyroid ablation rate was equivalent for the two thyroid-stimulating hormone (TSH) stimulation methods (thyroid hormone withdrawal [THW] and recombinant human TSH [rhTSH]) and the two iodine-131 ((131)I) activities (1.1 or 3.7 GBq). The objectives of this article were to present health-related quality-of-life (HRQoL) results and a cost-effectiveness evaluation performed alongside this trial. PATIENTS AND METHODS: HRQoL and utility were longitudinally assessed, from random assignment to the follow-up visit at 8 ± 2 months for the 752 patients with thyroid cancer, using the Short Form-36 and the EuroQoL-5D questionnaires, respectively. A cost-effectiveness analysis was performed from the societal perspective in the French context. Resource use (hospitalization for (131)I administration, rhTSH, sick leaves, and transportation) was collected prospectively. We used the net monetary benefit approach and computed cost-effectiveness acceptability curves for both TSH stimulation methods and (131)I activities. Sensitivity analyses of the costs of rhTSH were performed. RESULTS: At (131)I administration, THW caused a clinically significant deterioration of HRQoL, whereas HRQoL remained stable with rhTSH. This deterioration was transient with no difference 3 months later. rhTSH was more effective than THW in terms of quality-adjusted life-years (QALYs; +0.013 QALY/patient) but more expensive (+€474/patient). The probability that rhTSH would be cost effective at a €50,000/QALY threshold was 47% in France. The use of 1.1 GBq of (131)I instead of 3.7 GBq reduced per-patient costs by €955 (US$1,018) but with slightly decreased efficacy (-0.007 QALY/patient). CONCLUSION: rhTSH avoids the transient THW-induced deterioration of HRQoL but is unlikely to be cost effective at its current price.

Gated blood pool SPECT: The estimation of right ventricular volume and function is algorithm dependent in a clinical setting.

BACKGROUND: Gated blood pool SPECT (GBPS) requires further validation for the assessment of the right ventricle (RV). This study evaluated three algorithms: BP-SPECT, QBS, and TOMPOOL (results are referred using this order). We compared (1) their "quantitative-accuracy": estimation of RV ejection fraction (EF), end-diastolic volume (EDV), and cardiac output (CO); (2) their "qualitative-accuracy": threshold values allowing diagnosing an impairment of the RV function; (3) their reproducibility: inter-observer relative variability (IOV). METHODS AND RESULTS: Forty-eight consecutive patients underwent GBPS. Recommended reference standards were used: cardiac magnetic resonance imaging (CMR) (EDV, EF, n = 48), catheter measurements from thermodilution (TD) (CO, n = 25). (1) "Quantitative-accuracy": r = 0.42, 0.30, 0.42 for RVEF (CMR); r = 0.69, 0.77, 0.53 for RVEDV (CMR); 0.32, 0.36, 0.52 for RCO (TD). (2) "Qualitative-accuracy": optimal thresholds were 54.7%, 38.5%, 45.2% (AUC: 0.83, 0.80, 0.79) for RVEF; 229, 180, 94 mL (AUC: 0.83, 0.81, 0.81) for RVEDV; 4.1, 4.4, 2.6 L·minute(-1) (AUC: 0.73, 0.77, 0.80) for RCO. (3) Reproducibility: IOV was 5% ± 6%, 8% ± 12%, 17% ± 18% for RVEF; 6% ± 8%, 4% ± 4%, 21% ± 18% for RVEDV; 8% ± 8%, 11% ± 15%, 24% ± 20% for RCO. CONCLUSION: Diagnostic accuracies are similar. A CMR-based calibration is required for a quantitative-analysis (cautious interpretation) or an accurate qualitative analysis (thresholds must be adjusted). Automatic procedures (BP-SPECT, QBS) offer the best compromise accuracy/reproducibility.

Strategies of radioiodine ablation in patients with low-risk thyroid cancer.

BACKGROUND: It is not clear whether the administration of radioiodine provides any benefit to patients with low-risk thyroid cancer after a complete surgical resection. The administration of the smallest possible amount of radioiodine would improve care. METHODS: In our randomized, phase 3 trial, we compared two thyrotropin-stimulation methods (thyroid hormone withdrawal and use of recombinant human thyrotropin) and two radioiodine ((131)I) doses (i.e., administered activities) (1.1 GBq and 3.7 GBq) in a 2-by-2 design. Inclusion criteria were an age of 18 years or older; total thyroidectomy for differentiated thyroid carcinoma; tumor-node-metastasis (TNM) stage, ascertained on pathological examination (p) of a surgical specimen, of pT1 (with tumor diameter ≤1 cm) and N1 or Nx, pT1 (with tumor diameter >1 to 2 cm) and any N stage, or pT2N0; absence of distant metastasis; and no iodine contamination. Thyroid ablation was assessed 8 months after radioiodine administration by neck ultrasonography and measurement of recombinant human thyrotropin-stimulated thyroglobulin. Comparisons were based on an equivalence framework. RESULTS: There were 752 patients enrolled between 2007 and 2010; 92% had papillary cancer. There were no unexpected serious adverse events. In the 684 patients with data that could be evaluated, ultrasonography of the neck was normal in 652 (95%), and the stimulated thyroglobulin level was 1.0 ng per milliliter or less in 621 of the 652 patients (95%) without detectable thyroglobulin antibodies. Thyroid ablation was complete in 631 of the 684 patients (92%). The ablation rate was equivalent between the (131)I doses and between the thyrotropin-stimulation methods. CONCLUSIONS: The use of recombinant human thyrotropin and low-dose (1.1 GBq) postoperative radioiodine ablation may be sufficient for the management of low-risk thyroid cancer. (Funded by the French National Cancer Institute [INCa] and the French Ministry of Health; ClinicalTrials.gov number, NCT00435851; INCa number, RECF0447.).