The role of 18 F-FDG-PET/CT in the management of differentiated thyroid cancer

Nanobody-Based PET Imaging of CD47 Expression in Thyroid Carcinoma

Thyroid cancer is the most common malignant tumor in the endocrine system. A significant correlation has been established between elevated CD47 expression and the progression of thyroid carcinoma. This study aims to evaluate the diagnostic potential of immuno-positron emission tomography (immunoPET) utilizing CD47-targeting nanobodies in thyroid cancer tumor models. Immunohistochemistry (IHC) was employed to evaluate CD47 expression in patients with thyroid cancer, as well as in anaplastic thyroid carcinoma (ATC) xenograft tumor (OCUT-2C) and differentiated thyroid cancer (DTC) xenograft tumors (TPC-1 and BCPAP). Two nanobodies, C2 and its albumin-binding derivative (ABDC2), specifically targeting CD47 were labeled with 68Ga. The tracers were evaluated using immunoPET imaging in models of thyroid cancer. IHC revealed that CD47 was highly expressed in 34.69% of the tumor tissues from patients with thyroid cancer. Additionally, high levels of CD47 expression were observed in OCUT-2C, TPC-1, and BCPAP tumor tissues. Micro-PET imaging using [68Ga]Ga-NOTA-C2 and [68Ga]Ga-NOTA-ABDC2 demonstrated clear visualization of OCUT-2C tumors. Notably, the tumor uptake of [68Ga]Ga-NOTA-ABDC2 was significantly higher than that of [68Ga]Ga-NOTA-C2 at each imaging time point. Additionally, [68Ga]Ga-NOTA-ABDC2 exhibited specific uptake in the TPC-1 and BCPAP models. This study confirmed that [68Ga]Ga-NOTA-ABDC2 as a innovative PET imaging radiotracer targeting CD47 presented specific and higher tumor uptake to accurately identify CD47 expression and diagnose thyroid cancer. The clinical application of these imaging strategies may aid in selecting patients for CD47-targeted therapies and evaluating their subsequent responses.

Multiple Lung Metastases of Papillary Thyroid Carcinoma Detected by Detailed Pathological Examination: A Case Series

Papillary thyroid carcinoma (PTC) is the most common histological type of malignant thyroid tumor, and the lungs are one of the most frequent sites of distant metastasis. Although the progression of the disease remains slow even after the appearance of pulmonary metastases, and there are reports of long-term survival cases, no clear criteria have been established for performing aggressive biopsies of metastatic lesions. The subject was a 79-year-old male who was detected to have left cervical lymphadenopathy of unknown origin six years back. After further examination, cervical lymph node metastasis of PTC was suspected. Five years ago, the patient underwent total thyroidectomy and left cervical lymph node dissection. Two years ago, a nodule was observed in the right upper lobe of the lung, but it was managed with observation. A chest computed tomography scan revealed an irregular nodule measuring 15×14 mm in the S1 segment of the right upper lobe. Under suspicion of primary lung cancer, it was decided to perform intraoperative rapid diagnosis, and if malignant, a right upper lobectomy with mediastinal lymph node dissection would be carried out. Intraoperative rapid diagnosis confirmed malignancy, and a right upper lobectomy and mediastinal lymph node dissection were performed. Histopathological examination revealed findings of papillary adenocarcinoma, leading to a diagnosis of secondary lung cancer (pT1cN0cM0, pStage IA3). In addition, findings suggestive of multiple metastases from PTC were also observed. Similarly, no adjuvant therapy was administered for the PTC lung metastases, and a policy of careful observation was adopted. This case is a valuable report of pulmonary metastasis from PTC discovered through detailed histopathological examination of the resected lung. Furthermore, performing aggressive surgical biopsy and detailed histopathological examination to establish a diagnosis is worth considering from the perspective of personalized medical care for each patient.

Standard operating procedure (SOP) for cervical ultrasound cine loop video sequences in the follow-up of differentiated thyroid carcinoma (DTC)

RATIONALE AND OBJECTIVES

Cervical ultrasound (US) is crucial in the follow-up of differentiated thyroid cancer (DTC). However, there are no guidelines for its acquisition and documentation, particularly concerning the role of additional video sequences, known as US cine loops (UCL). The aim of this study is to examine the clinical relevance (CR) of a new Standard Operating Procedure (SOP) for cervical UCL in DTC follow-up.

MATERIALS AND METHODS

A retrospective analysis was conducted on all UCL examinations of DTC follow-up patients at a tertiary care center between January 2010 and February 2018 to determine their clinical significance. The patients were divided into two groups: those with no documented CR (UCL-nCR) and those with documented CR (UCL-CR). The study reviewed the respective written medical US reports that were validated by experienced residents. The UCL-CR were categorized in: confirmation of a suspicious finding that was identified during conventional live US (UCL-CRcon), identification of a suspicious finding that was not identified during conventional live US (UCL-CRide), and invalidation of a suspicious finding that was identified during conventional live US (UCL-CRinv).

RESULTS

A total of 5512 UCLs in 652 DTC patients were analyzed, with 71.5% women and a mean age of 50 years. More than 90% of the tumors were low-risk at initial staging. The mean number of UCLs per patient was 8.5 ± 4.6. Overall, 95 cases of UCL-CR were identified in 82 patients (12.6%), with a patient-based number needed to scan of 8. UCL-CRinv was the most common type of UCL-CR, accounting for 77 (81.1%) of cases. The occurrences of 12 UCL-CRcon (12.6%) and 6 UCL-CRide (6.3%) were correspondingly less frequent. The diagnosis of UCL-CR was confirmed in 91.6% of cases during the clinical course.

CONCLUSIONS

In 12.6% of the patients, the additional acquisition and archiving of cervical UCL revealed clinical relevance in the course of DTC disease. The invalidation of suspicious findings through the retrospective analysis of former UCL occurred as the most significant benefit of this method. The UCL SOP can be easily and quickly integrated into the US workflow.

[68Ga]Ga-LNC1007 versus 2-[18F]FDG in the evaluation of patients with metastatic differentiated thyroid cancer: a head-to-head comparative study

PURPOSE

This head-to-head comparison study aimed to compare the performance of [68Ga]Ga-FAPI-RGD (LNC1007) and 2-[18F]FDG PET/CT in the evaluation of patients with metastatic differentiated thyroid cancer (mDTC).

METHODS

Ten unexplained hyperthyroglobulinemia (UHTg) patients and 20 patients with definite metastatic lesions of thyroid cancer (DmDTC) were enrolled in the study. All patients underwent both [68Ga]Ga-LNC1007 and 2-[18F]FDG PET/CT within 1 week. The final diagnosis was based on histopathological results and a comprehensive evaluation of laboratory tests and multimodal imaging characteristics.

RESULTS

In patients with UHTg, [68Ga]Ga-LNC1007 PET/CT detected more metastatic lymph nodes (LNs) (17 vs. 15, P = 0.317) and lung lesions (2 vs. 0) than 2-[18F]FDG. In patients with DmDTC, [68Ga]Ga-LNC1007 PET/CT also detected more true positive lesions than 2-[18F]FDG (Total: 133 vs. 103, LN: 20 vs. 15, lung: 18 vs. 10, bone: 87 vs.73). [68Ga]Ga-LNC1007 PET/CT demonstrated significantly higher SUVmax (Total: 6.30 vs. 3.84, LN: 8.28 vs. 4.82, Lung: 3.31 vs. 1.49, Bone: 5.73 vs. 3.87, all P < 0.05) and TBR (Total: 6.92 vs. 4.93, LN: 6.48 vs. 4.16, Lung: 5.16 vs. 2.57, Bone: 7.22 vs. 5.41, all P < 0.05) in true positive lesions compared to 2-[18F]FDG. Specifically, the sensitivity of [68Ga]Ga-LNC1007 PET/CT was higher than that of 2-[18F]FDG in detecting lung and bone metastases (94.7% vs. 52.6% and 100% vs. 83.9%, all P < 0.05). [68Ga]Ga-LNC1007 PET/CT exhibited better specificity and accuracy in diagnosing LNs (96.9% vs. 66.7% and 96.3% vs. 68.5%, all P < 0.05). However, the specificity of [68Ga]Ga-LNC1007 for bone metastasis was inferior to 2-[18F]FDG (15.4% vs. 88.5%, P < 0.05).

CONCLUSION

Compared with 2-[18F]FDG, [68Ga]Ga-LNC1007 PET/CT could detect more metastatic lesions, with higher SUVmax and TBR, in patients with mDTC. [68Ga]Ga-LNC1007 had better accuracy in the diagnosis of LN and lung metastasis. Trial registration ClinicalTrials.gov NCT05515783. Registered 01 May 2022. URL of registry https://classic.

CLINICALTRIALS

gov/ct2/show/NCT05515783.

Techniques for Thyroidectomy and Functional Neck Dissection

Thyroidectomy is a commonly performed surgery for thyroid cancer, Graves' disease, and thyroid nodules. With the increasing incidence of thyroid cancer, understanding the anatomy and surgical techniques is crucial to ensure successful outcomes and minimize complications. This review discusses the anatomical considerations of the thyroid and neck, including lymphatic drainage and the structures at risk during thyroidectomy. Emphasis is placed on the significance of cautious dissection to preserve critical structures, such as the parathyroid glands and recurrent laryngeal nerve. Neck dissection is also explored, particularly in cases of lymph node metastasis, in which its proper execution is essential for better survival rates. Additionally, this review evaluates various thyroidectomy techniques, including minimally invasive approaches, highlighting their potential benefits and limitations. Continuous surgical knowledge and expertise updates are necessary to ensure the best results for patients undergoing thyroidectomy.