Prognostic value of post‐ablation 131 I scintigraphy in children with thyroid cancer

Prognostic implications of lymph node yield in pediatric patients with N1b papillary thyroid cancer

OBJECTIVE

To investigate whether lymph node (LN) yield influences clinical outcomes for pediatric patients with laterocervical lymph node metastasis (N1b) from papillary thyroid cancer (PTC).

METHODS

Conducted from January 1, 2008, to December 31, 2022, this was a cohort study of pediatric patients (aged ≤ 18 years) with N1b PTC who underwent total thyroidectomy and therapeutic LN dissection in the central and lateral compartments at 3 hospitals in southwest China in 2008-2021, with follow-up until 2022. Patients with distant metastasis were excluded. Univariate and multivariate Cox proportional hazards regression analyses were used to identify factors associated with persistent/recurrent diseases.

RESULTS

A total of 102 pediatric patients (median [range] age, 16 [6-18] years) were analyzed: 36 patients (35 %) with T1; 27 patients (26 %), T2; 18 patients (18 %), T3; and 21 patients (21 %), T4. During a median follow-up of 50 months (range, 12-154 months), persistent diseases occurred in 40 (39 %) patients. Receiver operating characteristic analysis identified LN yield cut-off (<42 LNs) to predict persistent diseases. Multivariate analysis revealed that a less-extensive lymphadenectomy (<42 LNs) was an independent risk factor for persistent diseases (hazard ratio, 2.4; 95 % confidence intervals, 1.09-5.29; P=.029).

CONCLUSIONS

Our study highlights that a higher LN yield may favorably influence prognosis in pediatric patients with N1b PTC.

The diagnostic efficacy and inappropriate biopsy rate of ACR TI-RADS and ATA guidelines for thyroid nodules in children and adolescents

BACKGROUND

This study is aimed at evaluating the diagnostic efficacy and unnecessary fine-needle aspiration (FNA) rate of ultrasound-based risk stratification for thyroid nodules in the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) and the American Thyroid Association (ATA) risk stratification systems.

METHODS

Children and adolescents with pathology confirmed thyroid nodules were retrospectively included in this study. A total of 217 thyroid nodules from multicenter of Union Medical College Hospital, China Japan Friendship Hospital and Civil Aviation Hospital were included, the diagnostic efficiency and unnecessary FNA rate were calculated according to ACR and ATA guidelines.

RESULTS

Among all thyroid nodules, 139 nodules were malignant, and 78 nodules were benign. Choosing ATA high suspicion and ACR TI-RADS TR5 as benign and malignant cut-off points, the area under the curve and sensitivity of ATA were higher than ACR (AUC: 0.887 vs 0.840, p=0.0037; sensitivity 81.3% vs 71.0%, P <0.049;specificity 96.2% vs 97.4%, p=1.000;specificity both 85.9%); choosing high/intermediate suspicion in ATA and ACR TR4/5 as benign and malignant cut-off points, the two guidelines demonstrated similar diagnostic efficacy (AUC:0.890 vs 0.897, p=0.6038, sensitivity 92.1% vs 93.5%, P =0.817;specificity both 85.9%, p=1.000). The inappropriate FNA rate of ACR guideline was relatively lower (ATA 42.9% vs ACR 27.2%, P <0.001). If ACR TI-RADS TR5 nodules less than 1.0cm were included in the FNA indication, the unnecessary biopsy rate would be further reduced to 17.9%.

CONCLUSION

This study indicated that both ATA and ACR TI-RADS risk stratification systems could provide a feasible differential diagnosis of benign and malignant thyroid nodules, while the ACR risk stratification system demonstrates a lower rate of inappropriate FNA rate. In addition, it was necessary to further study the minimum FNA threshold of thyroid nodules in Children and adolescents in order to reduce the missed biopsy rate of malignant nodules.

Predictive Factors for Recurrence of Papillary Thyroid Carcinoma in Children and Adolescents

Background

The incidence of papillary thyroid carcinoma (PTC) in children and adolescents has increased, but the data on long-term outcomes are limited. There are few literatures on the clinicopathological characteristics and prognosis of PTC in children and adolescents in China. Therefore, it is necessary to identify clinicopathological features to precisely predict clinical prognosis and to help choose the optimal method and perform the best therapeutic regimen.

Methods

This study was a retrospective analysis of patients undergoing thyroidectomy at Tianjin Medical University Cancer Institute and Hospital. We analyzed the factors related to the clinicopathological features and prognosis of PTC in children and adolescents.

Results

A total of 95 juvenile PTC patients who underwent thyroidectomy were enrolled. Our research found that patients with younger age (<14 years) were predominantly multifocal and have positive preoperative thyroglobulin (Tg) and higher recurrence rate, and their number of lymph node metastases (LNMs) was more than that of the older group (14–18 years). Maximal tumor size >2 cm, T stage, and multifocality were the risk factors for LNM and the number of LNM (p < 0.05). Multivariate analysis displayed the number of central LNM as the independent risk factor for lateral LNM, and multifocality was the independent risk factor for the number of central and lateral LNM. Younger age at diagnosis, positive preoperative thyroid-stimulating hormone (TSH), maximal tumor size >2 cm, lateral LNM, number of LNM, N staging, and American Thyroid Association (ATA) pediatric risk were related to poor prognosis in PTC patients (p < 0.05). Cox regression analysis found that younger age at diagnosis and positive preoperative TSH were independent risk factors for recurrence of PTC in children and adolescents.

Conclusions

Our study showed that the clinicopathological characteristics of younger age compared with older age were as follows: highly aggressive, prone to metastases, and higher recurrence rate. In our opinion, patients with characteristics such as younger age at diagnosis, positive preoperative TSH, maximal tumor size >2 cm, lateral LNM, and number of LNM >5 may be considered for prophylactic or therapeutic dissection of additional metastatic LNs by high-volume surgeons to prevent and reduce the recurrence rate of patients during long-term follow-up.

Prognostic value of lymph node ratio in children and adolescents with papillary thyroid cancer

OBJECTIVE

Neck lymph node (LN) metastasis is a common feature of paediatric papillary thyroid cancer, and LN ratio (LNR) is defined as the ratio of the number of positive LNs excised to the total number of removed. Unlike in adults, few data are available regarding the clinical implication of LNR in the paediatric population. Our purpose was to investigate the association of LNR with clinical outcomes in paediatric papillary thyroid cancer.

DESIGN & METHODS

The study retrospectively reviewed 136 consecutive children and adolescents with papillary thyroid cancer and LN involvement but no initial distant metastasis. Initial treatment, included in all patients a total thyroidectomy with central and/or lateral neck dissection followed by radioactive iodine ablation. Within the neck dissections, total number of LNs removed, total positive LNs and LN ratios were determined. The effect of clinicopathologic characteristics and intraoperative findings on persistent and recurrent diseases were analysed by univariate and multivariate analyses.

RESULTS

Median number of positive LNs was 9, and median LNR was 0.4. During a median follow-up of 49 months (range, 12.0-139 months), persistent disease occurred in 43 (31.6%) patients. The multivariable analysis showed that age and LNR were the independent factors predictive of persistent disease. Patients with a LNR >0.34 exhibited a threefold higher risk of persistent disease after initial therapy than the counterparts (P = .02).

CONCLUSION

Our findings suggest that LNR was an independent determinant predictive of persistent disease after initial therapy in children and adolescents with papillary thyroid cancer.

Clinical applications of single-photon emission computed tomography/computed tomography in post-ablation 131iodine scintigraphy in children and young adults with differentiated thyroid carcinoma

BACKGROUND

The utility of integrated single-photon emission computed tomography/computed tomography (SPECT/CT) in children and young adults with differentiated thyroid carcinoma is incompletely studied.

OBJECTIVE

To determine the value of adding SPECT/CT to conventional whole-body scintigraphy in post-ablation iodine-131 (¹³¹I) scintigraphy for children and young adults with differentiated thyroid carcinoma.

MATERIALS AND METHODS

Planar scintigraphy and SPECT/CT were performed on 42 post-surgical children and young adults (32 female, 10 male; mean age 14.3±4.9 years, range 7-20 years) with differentiated thyroid carcinoma (39 papillary, 2 follicular, 1 mixed) 5 days after the therapeutic administration of 1.9-7.4 GBq of ¹³¹I. Planar and SPECT/CT images were interpreted independently, and sites of uptake were categorized as positive or equivocal with respect to thyroid bed, lymph node and distant metastasis uptake. An experienced thyroid endocrinologist used a combination of surgical histopathology and scintigraphic findings to determine whether the addition of SPECT/CT would change patient management.

RESULTS

Planar scintigraphy evidenced 88 radioiodine-avid foci and SPECT/CT confirmed all foci. No additional foci were disclosed by SPECT/CT. SPECT/CT correctly classified 16/88 (18%) foci that were unclear or wrongly classified at planar scintigraphy. Globally, SPECT/CT showed an incremental value over planar scintigraphy in 9 (21.4%) patients and changed therapeutic management in 3 (7.1%; 95% confidence interval, 2-20%) patients.

CONCLUSION

SPECT/CT improved localization and characterization of focal ¹³¹I uptake on post-ablation whole-body scintigraphy in children and young adults with differentiated thyroid carcinoma. Further prospective evaluation in a larger series is justified to prove the effect of post-ablation SPECT/CT-based management decisions.

Influence of body mass index at diagnosis on outcome of thyroid cancer in children and adolescents

PURPOSE

To systemically examine the relationship between body mass index, the extent of thyroid cancer and metastatic burden at diagnosis, and overall outcomes in children and adolescents with thyroid cancer.

METHODS

A retrospective series of children and adolescents with differentiated thyroid cancer who underwent total thyroidectomy and ¹³¹I therapy was analyzed. Body mass index (BMI) at the time of surgery was assessed. The Chinese age- and sex-specific BMI percentile criteria for screening overweight and obesity in children and adolescents were used to define the overweight and obesity among patients. The relationship between BMI and clinicopathological features and clinical outcomes of the disease was evaluated by logistic regression modeling, incorporating the eighth edition of the American Joint Committee on Cancer TNM staging system and the 2015 American Thyroid Association guidelines.

RESULTS

This study included 181 children and adolescents with differentiated thyroid cancer (82.9% females, median age 17 years). The mean BMI was 21.0 ± 3.9 kg/m²; 77.9% of the patients (N = 141) were normal weight, 13.2% (N = 24) were overweight, and 8.8% (N = 16) were obese. No positive associations were noted between BMI and T, N, or M stage on logistic regression analyses. The absence of an association was also demonstrated on analysis by BMI categories. After a median follow-up of 51 months, 114 children and adolescents (63.0%) had achieved excellent response to therapy. No associations were noted for persistent/recurrent disease among BMI groups.

CONCLUSION

Our study highlights the absence of increased disease burden at the time of thyroid cancer diagnosis in pediatric patients with high BMI along with the same prognosis compared with normal-weight pediatric patients.