Yan-Li Xue

Rare metastases of differentiated thyroid carcinoma: pictorial review

Differentiated thyroid cancer (DTC) is usually indolent with good prognosis and long-term survival. However, DTC distant metastasis is often a grave event and accounts for most of its disease-specific mortality. The major sites of distant metastases are the lung and bone. Metastases to the brain, breast, liver, kidney, muscle, and skin are rare or relatively rare. Nevertheless, recognizing rare metastases from DTC has a significant impact on the clinical decision making and prognosis of patients. (131)I single photon emission computed tomography/computed tomography ((131)I-SPECT/CT) can provide both metabolic and anatomic information about a lesion; therefore, it can better localize and define the (131)I-WBS findings in DTC patients. In this pictorial review, the imaging features of a range of rare metastases from DTC are demonstrated, with a particular emphasis on the (131)I-SPECT/CT diagnostic aspect.

Value of 131I SPECT/CT for the evaluation of differentiated thyroid cancer: a systematic review of the literature

PurposeIn the present study, we performed a systematic review of the current literature to assess the incremental value of 131I single photon emission computed tomography (SPECT)/CT for the management of patients with differentiated thyroid cancer (DTC).MethodsThe search of PubMed/MEDLINE and EMBASE databases to identify studies and reference lists for articles was conducted using the terms “SPECT or SPECT/CT or SPECT-CT or single photon emission computed tomography/computed tomography and thyroid carcinoma or thyroid cancer.” Studies reporting the clinical value of 131I SPECT/CT were selected. All studies included were assessed with the Quality Assessment of Diagnostic Accuracy Studies-2 tool (QUADAS-2). Two independent reviewers selected the studies, summarized and tabulated the data, and pooled estimates were obtained. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed.ResultsA total of 14 studies involving 1,066 patients met the inclusion criteria. Data obtained included the impact of 131I SPECT/CT on staging or risk classification (three studies), diagnostic accuracy (six studies), and follow-up (five studies).ConclusionIntegrated SPECT/CT is a useful tool for the diagnosis, staging, risk stratification, and follow-up of DTC. The impact of 131I SPECT/CT on the management of patients with thyroid cancer was evaluated.

Uncommon metastases from differentiated thyroid carcinoma

Differentiated thyroid carcinoma (DTC) usually behaves in an indolent manner with low metastatic potential. The major sites of distant metastases are the lung and bone. Metastases to the brain, eye, breast, liver, kidney, muscle and skin are rare or relatively rare. These metastases have almost always appeared in patients with advanced disease and are often associated with poor prognosis but overlooked in clinical practice. Recognizing them has a significant impact on clinical decision-making and prognosis of the patients. Treatment in these patients should be individualized and an alternative therapeutic approach should be considered. Care should be taken to determine whether a (131)I uptake focus found at an unexpected site of (131)I- whole body scan (WBS) is a DTC metastasis or a false-positive (131)I uptake. Imaging with (131)I-SPET/CT is of incremental value in the finding of rare metastases from DTC. In conclusion, DTC can have unusual metastatic presentations and patterns. Post-therapy (131)I-WBS and (131)I-SPET/CT play an important role in the management of patients with DTC.

Comparison of the diagnostic and prognostic values of 99mTc-MDP-planar bone scintigraphy, 131I-SPECT/CT and 18F-FDG-PET/CT for the detection of bone metastases from differentiated thyroid cancer.

Objective The aim of this study was to compare the diagnostic and prognostic values of 99mTc-MDP-planar bone scintigraphy (99mTc-MDP-BS), 131I single-photon emission computed tomography/computed tomography (131I-SPECT/CT) and 18F-fluorodeoxyglucose (18F-FDG)-PET/CT for the detection of bone metastases from differentiated thyroid cancer (DTC). Methods Eighty patients with DTC with suspected bone metastases from DTC were retrospectively analysed. All patients were examined with 99mTc-MDP-BS, 131I-SPECT/CT and 18F-FDG-PET/CT, with a maximum interval of 2 months between scans. The diagnostic performances of 99mTc-MDP-BS, 131I-SPECT/CT and 18F-FDG-PET/CT were investigated and compared. Univariate and multivariate analyses were carried out to evaluate the effects of variables on the survival of patients. Results Out of the 80 patients with 148 foci, 43 with 106 foci were diagnosed as being true positive for bone metastases from DTC. In patient-based analysis, the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of 99mTc-MDP-BS were 79.07, 83.78, 85.00, 77.50 and 81.25%, respectively; those of 131I-SPECT/CT were 93.02, 97.30, 97.56, 92.31 and 95.00%, and those of 18F-FDG-PET/CT were 86.05, 94.59, 94.87, 85.36 and 87.80%, respectively. In lesion-based analysis, the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of 99mTc-MDP-BS were 72.64, 73.81, 87.50, 51.67 and 72.97%, respectively; those of 131I-SPECT/CT were 92.45, 97.62, 98.99, 83.67 and 93.92%, and those of 18F-FDG-PET/CT were 85.85, 88.10, 94.50, 71.15 and 86.49%, respectively. Comparing the receiver-operating characteristic area using the McNemar test, both 131I-SPECT/CT and 18F-FDG-PET/CT were found to be superior to 99mTc-MDP-BS for the detection of bone metastases from DTC in patient-based and lesion-based analyses (P<0.05). Patient-based analysis showed that there were no significant differences between 131I-SPECT/CT and 18F-FDG-PET/CT (P=0.087) but lesion-based analysis revealed that 131I-SPECT/CT was superior to 18F-FDG-PET/CT (P=0.002). For the association between these image patterns and the prognosis of DTC patients, 18F-FDG positivity was the factor predicting a poor prognosis. Conclusion 131I-SPECT/CT and 18F-FDG-PET/CT demonstrated high diagnostic performance in detecting bone metastases from DTC. 99mTc-MDP-BS might be completely replaced by 131I-SPECT/CT in combination with 18F-FDG-PET/CT in the management of DTC patients with bone metastases. 18F-FDG-PET/CT positivity was an independent factor associated with poor prognosis.

131I SPECT/CT: a one-station imaging modality in the management of differentiated thyroid cancer

In patients with differentiated thyroid carcinoma (DTC), single-photon emission computed tomography/computed tomography (SPECT/CT) applied to diagnostic or therapeutic radioiodine (131I) whole-body scintigraphy (WBS) may accurately localize and help to distinguish benign from malignant sites of 131I uptake, with the potential to alter the management plan. 131I SPECT/CT is increasingly being used to evaluate patients with DTC and shows promise for improving imaging specificity and reducing false-positive results. Pre-ablation scans with 131I SPECT/CT contribute to the staging of thyroid cancer and the identification of regional and distant metastases prior to radioiodine therapy. Post-therapy scans with 131I SPECT/CT improve detection and localization of 131I accumulation in lymph node metastases and distant metastases compared with planar WBS and reduce the number of equivocal diagnoses and the need for additional cross-sectional imaging.

Comparative serum proteomic analysis identified afamin as a downregulated protein in papillary thyroid carcinoma patients with non-131I-avid lung metastases.

BackgroundThe loss of 131I uptake ability in metastases from differentiated thyroid carcinoma (DTC) is becoming a major obstacle in radioiodine treatment. However, there is no effective way to screen for 131I uptake ability in metastases. The identification of differentially expressed proteins by serum proteomics may contribute to our understanding of the mechanisms underlying the dedifferentiation of DTC. Materials and methodsSerum samples were obtained from papillary thyroid carcinoma patients with non-131I-avid lung metastases and 131I-avid lung metastases. Differential protein analysis was performed using two-dimensional gel electrophoresis. Candidate protein spots showing differences in expression between the two groups were identified by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and were validated by western blotting. ResultsWe found that afamin is downregulated in the serum of papillary thyroid carcinoma patients with non-131I-avid lung metastases. ConclusionAfamin may be a potential serum biomarker for early screening of 131I uptake ability in DTC metastases and could therefore be of value in guiding radioiodine treatment decisions.

An unusual 131I-avid adrenal metastasis from follicular thyroid carcinoma identified by 131I-SPECT/CT.

The adrenal gland is an uncommon site of metastasis from differentiated thyroid carcinoma, and I-avid adrenal metastatic lesions are even rarer. Here, we describe a 54-year-old woman with I-avid adrenal metastasis from follicular thyroid carcinoma identified using I whole-body scan (I-WBS) and I-SPECT/CT. I-SPECT/CT allowed superior localization of the equivocal I uptake in the I-WBS. It provides metabolic and anatomic information about a lesion, resulting in accurate localization and improved definition of I-WBS findings.

Unusual Case of Solitary Functioning Bone Metastasis From a “Parathyroid Adenoma”: Imagiologic Diagnosis and Treatment With Percutaneous Vertebroplasty—Case Report and Literature Review

BACKGROUND Parathyroid carcinoma is a rare endocrine malignancy that accounts for a small percentage of patients with primary hyperparathyroidism. Here, an unusual patient with parathyroid carcinoma misdiagnosed as a parathyroid adenoma was reported. A solitary L4 vertebral metastasis, which was localized by technetium-99m-labelled methoxyisobutyl isonitrile ((99m)Tc-MIBI) single photon emission computed tomography (SPECT)/computed tomography (CT) fusing images, was successfully treated with percutaneous vertebroplasty (PVP) for the first time. PATIENT AND METHODS A 53-year-old man with primary hyperparathyroidism and a palpable mass in the right neck was referred. A right unilateral parathyroidectomy was performed. A pathological diagnosis of parathyroid adenoma was made; however, hyperparathyroidism persisted with a serum calcium of 4.51 mmol/L and a PTH of 3235 pg/mL. Early and delayed images of the (99m)Tc-MIBI whole-body scan revealed abnormal (99m)Tc-uptake in the lower abdomen. The delayed (99m)Tc-MIBI SPECT/CT fusion images found that the lower abnormal (99m)Tc-MIBI uptake was located in the area of osteolytic destruction of the L4 vertebra. A bone metastasis from parathyroid carcinoma was diagnosed based on histopathological evaluation and immunohistochemical staining. PVP was performed to treat the osteolytic destruction of the L4 vertebra. The PTH level decreased to normal within 1 week after PVP. CONCLUSION (99m)Tc-MIBI SPECT/CT scan may be a useful and suitable method by which to localize functioning distant metastases from the parathyroid cancer when serum PTH and calcium levels remain greatly elevated after parathyroidectomy. PVP may be an effective procedure in eliminating cancer cells, reducing serum PTH levels, preventing bone fractures, and improving the quality of life of patients.

Percutaneous osteoplasty combined with radioiodine therapy as a treatment for bone metastasis developing after differentiated thyroid carcinoma.

BACKGROUND Bone metastasis developing after differentiated thyroid carcinoma (DTC) is common, and in most cases, this condition leads to osteolysis. However, treatment of bone metastases in DTC patients is a great challenge. The purpose of this study was to evaluate the effectiveness of percutaneous osteoplasty (POP) combined with radioiodine therapy for treating bone metastasis developing after DTC. PATIENTS AND METHODS We retrospectively studied 8 patients who had undergone POP combined with radioiodine therapy for bone metastases after DTC. All patients underwent total thyroidectomy and were administered an oral dose of 131I (3.7 GBq, 100 mCi) for ablation of the residual thyroid. Thereafter, a POP was performed at 2 to 3 months followed by 2 to 5 sessions of radioiodine therapy every 4 to 6 months after the first 131I therapy. The therapeutic effectiveness of this treatment was evaluated on the basis of the changes in serum thyroglobulin (Tg) level and imaging characteristics, palliation of bone pain, and alleviation of neurologic symptoms. RESULTS After POP, the mean serum Tg level decreased by 86.0% (range, 68.1%-99.3%). The mean serum Tg level markedly declined further by 67.4% (range, 37.1%-90.2%) after repeated radioiodine therapy. All the patients experienced immediate and substantial alleviation of bone pain and neurologic symptoms, and their quality of life markedly improved. The bone-destructive lesions were filled with bone cement to enhance skeletal stability. No severe complications developed. CONCLUSION POP, a minimally invasive procedure, combined with radioiodine therapy seems to be highly effective in providing pain relief and bone stability and in improving the quality of life of DTC patients with bone metastases. After POP, radioiodine therapy is essential.

Abnormal ¹³¹I uptake in a benign serous ovarian cystadenoma mimicking bladder physiological uptake.

Iodine-131 (I) whole-body scan is usually a routine practice for the management of patients with differentiated thyroid carcinoma after I therapy. The correct interpretation of radioiodine scans is critical and can avoid unnecessary therapeutic doses. I SPECT/CT plays an important role in the precise localization and characterization of I avid foci. We present a special case imaging resulting from a benign serous cystadenoma of the ovary mimicking physiological uptake of the urinary bladder, which was identified by I whole-body scan and I SPECT/CT.