Inability of Radioiodine Remnant Ablation to Improve Postoperative Outcome in Adult Patients with Low-Risk Papillary Thyroid Carcinoma.

OBJECTIVE: To determine whether radioiodine remnant ablation (RRA) reduces cause-specific mortality (CSM) or tumor recurrence (TR) rate after bilateral lobar resection (BLR). PATIENTS AND METHODS: There were 2952 low-risk adult papillary thyroid cancer (LRAPTC) patients (with MACIS scores <6) who underwent potentially curative BLR during 1955-2014. During 1955-1974, 1975-1994, and 1995-2014, RRA was administered in 3%, 49%, and 28%. Statistical analyses were performed using SAS software. RESULTS: During 1955-1974, the 20-year CSM and TR rates after BLR alone were 1.0% and 6.8%; rates after BLR+RRA were 0% (P=.63) and 5.9% (P=.82). During 1975-1994, post-BLR 20-year rates for CSM and TR were 0.3% and 7.5%; after BLR+RRA, rates were higher at 0.9% (P=.31) and 12.8% (P=.01). When TR rates were examined separately for 448 node-negative and 317 node-positive patients, differences were nonsignificant. In 1995-2014, post-BLR 20-year CSM and TR rates were 0% and 9.2%; rates after BLR+RRA were higher at 1.4% (P=.19) and 21.0% (P<.001). In 890 pN0 cases, 15-year locoregional recurrence rates were 3.4% after BLR and 3.7% after BLR+RRA (P=.99). In 740 pN1 patients, 15-year locoregional recurrence rates were 10% higher after BLR+RRA compared with BLR alone (P=.01). However, this difference became nonsignificant when stratified by numbers of metastatic nodes. CONCLUSION: RRA administered to LRAPTC patients during 1955-2014 did not reduce either the CSM or TR rate. We would therefore not recommend RRA in LRAPTC patients undergoing BLR with curative intent.

Mild iodine deficiency during pregnancy is associated with reduced educational outcomes in the offspring: 9-year follow-up of the gestational iodine cohort.

CONTEXT: Severe iodine deficiency (ID) during gestation is associated with neurocognitive sequelae. The long-term impact of mild ID, however, has not been well characterized. OBJECTIVE: The purpose of this study was to determine whether children born to mothers with urinary iodine concentrations (UICs) <150 µg/L during pregnancy have poorer educational outcomes in primary school than peers whose mothers did not have gestational ID (UIC ≥150 µg/L). DESIGN: This was a longitudinal follow-up (at 9 years old) of the Gestational Iodine Cohort. Pregnancy occurred during a period of mild ID in the population, with the children subsequently growing up in an iodine-replete environment. SETTING AND PARTICIPANTS: Participants were children whose mothers attended The Royal Hobart Hospital (Tasmania) antenatal clinics between 1999 and 2001. MAIN OUTCOME MEASURES: Australian national curriculum and Tasmanian state curriculum educational assessment data for children in year 3 were analyzed. RESULTS: Children whose mothers had UIC <150 µg/L had reductions of 10.0% in spelling (-41.1 points, 95% confidence interval [CI], -68.0 to -14.3, P = .003), 7.6% in grammar (-30.9 points, 95% CI, -60.2 to -1.7, P = .038), and 5.7% in English-literacy (-0.33 points, 95% CI, -0.63 to -0.03, P = .034) performance compared with children whose mothers' UICs were ≥150 µg/L. These associations remained significant after adjustment for a range of biological factors (maternal age at birth of child, gestational length at time of birth, gestational age at time of urinary iodine collection, birth weight, and sex). Differences in spelling remained significant after further adjustment for socioeconomic factors (maternal occupation and education). CONCLUSIONS: This study provides preliminary evidence that even mild iodine deficiency during pregnancy can have long-term adverse impacts on fetal neurocognition that are not ameliorated by iodine sufficiency during childhood.

Current strategies for surgical management and adjuvant treatment of childhood papillary thyroid carcinoma.

Childhood papillary thyroid carcinoma is associated with more locally aggressive and more frequent distant disease than its adult counterpart. Recurrence rates tend to be higher in children, but cause-specific mortality remains low. Optimal initial treatment of childhood papillary thyroid carcinoma should include total or near-total thyroidectomy and central compartment node clearance. Modified neck dissections should be performed for biopsy-proven lateral neck disease. Every effort should be made to maintain parathyroid and laryngeal nerve function. Radical neck dissections are to be avoided. Radioiodine remnant ablation (RRA), appropriate thyroid hormone suppressive therapy (THST), and judicious use of therapeutic doses of (131)I are applied to achieve a disease-free status, which is most often confirmed by negative neck ultrasonography, negative whole-body scan (either withdrawal or recombinant human thyroid-stimulating hormone-stimulated), and extremely low levels of serum thyroglobulin. Appropriate utilization of (131)I, THST, repeat surgery, external beam radiotherapy, and rarely chemotherapy may provide long-term palliation and some cures in patients with recurrent/persistent disease. Follow-up should be lifelong, and the care of children after age 17 should subsequently be transferred to adult-care endocrinologists with expertise in managing thyroid neoplasia. Optimal surgical management can be achieved if adequate operations are routinely carried out by "high-volume" thyroid surgeons with expertise in the care of children. Nowhere is a multidisciplinary approach (endocrinologists, surgeons, nuclear medicine physicians, pediatricians, pathologists, oncologists) more critical than in the long-term management of papillary thyroid carcinoma that presents during childhood.

Lack of impact of radioiodine therapy in tg-positive, diagnostic whole-body scan-negative patients with follicular cell-derived thyroid cancer.

Several reports have suggested a benefit from radioactive iodine (RAI) therapy in Tg-positive, whole-body scan-negative patients with follicular cell-derived thyroid cancer, who were said to have high rates of visualization of uptake in metastases after therapeutic doses of RAI. We sought to evaluate the rate of visualization of RAI uptake in these patients and determine the effect of such therapy on tumor progression and Tg levels. We studied 24 consecutive patients who had been treated with high-dose RAI, four of whom had no evidence of metastasis or persistent cancer. Our results showed that four patients had some uptake in posttherapy scans: in the neck, lung, and mediastinal metastases in one patient, in the thyroid remnant in two, and in a possible neck microrecurrence in one. In 13 patients with macrometastases-tumors 1 cm or greater-tumors progressed and serum Tg increased; five have died of thyroid cancer. The disease remained stable in the seven patients with micrometastases. We concluded that in high-risk patients with follicular cell-derived thyroid cancer with high Tg levels and negative diagnostic whole-body scans, only a small number showed meaningful uptake after high doses of RAI. Therefore, widespread use of empiric RAI therapy for such patients who have a large tumor burden should not be encouraged.