Thyroid Remnant Estimation by Diagnostic Dose (131)I Scintigraphy or (99m)TcO4(-) Scintigraphy after Thyroidectomy: A Comparison with Therapeutic Dose (131)I Imaging

A systematic review and meta-analysis comparing tumor progression and complications between radiofrequency ablation and thyroidectomy for papillary thyroid carcinoma

BACKGROUND

Papillary thyroid cancer (PTC) is the most frequent thyroid cancers worldwide. The efficacy and acceptability of radiofrequency ablation (RFA) in the treatment of PTC have been intensively studied. The aim of this study is to focus on extra detailed that may influent for PTC or papillary thyroid microcarcinoma (PTMC).

MATERIALS AND METHODS

We identified a total of 1,987 records of a primary literature searched in PubMed, Embase, Cochrane Library, and Google Scholar by key words, from 2000 to 2022. The outcome of studies included complication, costs, and local tumor progression. After scrutiny screening and full-text assessment, six studies were included in the systematic review. Heterogeneity was estimated using I2, and the quality of evidence was assessed for each outcome using the GRADE guidelines.

RESULTS

Our review enrolled 1,708 patients reported in six articles in the final analysis. There were 397 men and 1,311 women in the analysis. Two of these studies involved PTC and four focused on PTMC. There were 859 patients in the RFA group and 849 patients in the thyroidectomy group. By contrast, the tumor progression of RFA group was as same as that surgical groups [odds ratio, 1.31; 95% CI, 0.52-3.29; heterogeneity (I2 statistic), 0%, p = 0.85]. The risk of complication rates was significantly lower in the RFA group than that in the surgical group [odds ratio, 0.18; 95% CI, 0.09-0.35; heterogeneity (I2 statistic), 40%, p = 0.14].

CONCLUSIONS

RFA is a safe procedure with a certain outcome for PTC. RFA can achieve a good efficacy and has a lower risk of major complications.

Can shear wave elastography determine remnant thyroid tissue in the early postoperative period in patients with differentiated thyroid carcinoma?

PURPOSE

This study aims to investigate the usability of ultrasonography (US) and shear wave elastography (SWE) in detecting remnant thyroid tissue (RTT) within the first three postoperative months in patients who underwent total thyroidectomy (TT) for differentiated thyroid cancer (DTC) and who were scheduled for radioiodine (RAI) ablation therapy.

METHODS

Sixty-nine patients who underwent a TT operation due to DTC were included in the study. The participant's thyroid surgical bed was first evaluated by thyroid scintigraphy and then by greyscale US and SWE to investigate RTT. The participants were divided into two groups, those with and those without RTT. SWE quantitative data were compared between the two groups. Receiver operating characteristic (ROC) curve analysis was performed to determine the best cut-off values for stiffness and velocity in distinguishing RTT.

RESULTS

A total of 149 regions were analysed in 69 participants (43 females, 26 males). The average time elapsed after the operation was 65.2 ± 24.1 days. RTT was determined by scintigraphy and US-SWE in 38 (55%) patients. The stiffness and velocity values were significantly higher in the group with RTT than in the group without RTT. To distinguish RTT from the thyroid bed, the best cut-off values for stiffness and velocity were 15.7 kPa and 2.12 m/s, respectively.

CONCLUSIONS

US with SWE can detect RTT in the early postoperative period in patients who have undergone TT due to DTC and who are scheduled for RAI treatment. The use of US and SWE will be particularly beneficial in patients with RTT but who have false-negative Tg levels and RTT that is not I-131 avid.

Primary accessory thyroid carcinoma with negative 99mTcO4- SPECT/CTimaging: a case report and literature review

Introduction

In contrast to orthotopic thyroid carcinoma, primary accessory thyroid carcinoma is very rare. We herein report a case involving primary accessory thyroid carcinoma in a patient with normal ultrasonography of the orthotopic thyroid and negative ^99mTcO₄⁻ single-photon emission computed tomography (SPECT) scintigraphy.

Case presentation: A computed tomography (CT) scan showed soft tissue nodules at the left anterior edge of the thyroid cartilage. To determine whether the mass was accessory thyroid tissue, ^99mTcO₄⁻ SPECT/CT was performed, and the findings were negative. However, pathological examination after resection showed that mass was a primary accessory thyroid papillary carcinoma. The 1-year follow-up ultrasound showed no lesion at the orthotropic thyroid and neck incision sites.

Conclusions

This case suggests that negative ^99mTcO₄⁻ SPECT/CT imaging may not completely exclude the possibility of thyroid carcinoma. A punch biopsy or postoperative pathological examination is necessary for the diagnosis.