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 diseasespecific 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.

Context: Data from a large cohort of patients with pulmonary metastases from differentiated thyroid cancer (DTC) were retrospectively analyzed. Objective: To assess the effect of radioiodine therapy and investigate the prognostic factors of survival for patients with pulmonary metastasis secondary to DTC.

131 I whole-body scintigraphy (WBS) is a highly sensitive method for the detection of differentiated thyroid tumors and metastases. However, a lack of anatomic landmarks and the physiologic accumulation of the tracer complicate interpretation of the images. This prospective study was designed to evaluate the incremental value of 131 I SPECT/CT over planar WBS in the management of patients with differentiated thyroid carcinoma (DTC). Methods: Planar imaging was performed on 66 consecutive DTC patients who were considered to have locally advanced or metastatic disease after total or nearly total thyroidectomy. SPECT/CT was added for patients whose planar findings were inconclusive. The planar images were interpreted by 2 experienced nuclear medicine physicians. Interpretation of the SPECT/CT images was a consensus opinion of one of the nuclear medicine physicians and an experienced radiologist. Fusion images were considered to improve image interpretation when they better localized sites of increased 131 I uptake. The final diagnosis was verified by pathologic findings, other imaging modalities, and clinical follow-up. Both site-based and patient-based analyses were performed, and the impact of SPECT/CT results on therapeutic strategy was assessed. Results: A total of 232 foci were observed by 131 I WBS, including 33.2% of foci localized in the thyroid bed, 62.1% due to malignant lesions, and 4.7% caused by nonthyroidal physiologic or benign uptake or a contaminant. Overall, 37 SPECT/CT studies were performed on 23 patients, whose planar images showed 81 inconclusive lesions. Precise localization and characterization of 131 I-avid foci were achieved through 131 I SPECT/CT in 69 (85.2%) and 67 (82.7%) of the 81 foci, respectively. Fusion images were considered to be of benefit in 17 (73.9%) of 23 patients. The therapeutic strategy was changed in 8 (47.1%) of 17 patients. Uncommon metastatic lesions were found in 9 (13.6%) of 66 patients with regard to SPECT/CT fusion images. Conclusion: Fusion of SPECT and CT images was of incremental value over WBS in increasing diagnostic accuracy, reducing pitfalls, and modifying therapeutic strategies in 73.9% of DTC patients. As SPECT/CT techniques emerge, 131 I SPECT/CT may demonstrate higher value than WBS in the management of DTC.

Sorafenib at a dose of 200 mg twice daily has a potential therapeutic effect and is well tolerated in Chinese patients with PTC and radioiodine-refractory pulmonary metastases. Further study is warranted with a larger cohort of patients.

(131)I therapy is a feasible and effective treatment for DTC bone metastases. A better prognosis can be accomplished in patients who had a single metastatic lesion, only bone metastasis, or underwent bone surgery before (131)I therapy.

The advent of biologically targeted agents and increased understanding of thyroid carcinogenesis have generated much interest in the development of biologically targeted therapeutic agents for thyroid cancer. Among them, sorafenib is the most commonly studied drug. The current meta-analysis was carried out to estimate the efficacy and safety of sorafenib administered in radioiodine-refractory differentiated thyroid cancer patients. An electronic search was conducted using PubMed/MEDLINE and EMBASE. Statistical analyses were carried out using either random-effects or fixed-effects models according to heterogeneity. All the statistical analyses were carried out using the Stata version 12.0 software. Seven eligible studies were identified. The final results indicated that 22% of the patients (95% CI: 15-28) achieved a partial response. Hand-foot syndrome, diarrhea, fatigue, rash, weight loss, and hypertension were the most frequently observed adverse effects (AEs) associated with sorafenib use and the incidence of these AEs (all grades) was 80% (95% CI: 68-91), 68% (95% CI: 59-77), 67% (95% CI: 57-78), 66% (95% CI: 50-82), 52%(95% CI: 33-72), and 31% (95% CI: 21-42) respectively. Sixty-two percent (95% CI: 36-89) patients required dose reductions due to toxicity of sorafenib. As far as PR and AEs are concerned, the results of this meta-analysis indicate that sorafenib has a modest effect in patients with radioiodine-refractory differentiated thyroid cancer and the high incidence of AEs associated with this agent may affect the quality of patients' lives. Though the use of sorafenib in the treatment of radioiodinerefractory differentiated thyroid cancer is considered promising by most physicians working in this field, more effective agents with less toxicity and cost are still needed.

(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.

The characteristics of lymphedema on radionuclide lymphoscintigraphy were studied, and the diagnostic value of radionuclide lymphoscintigraphy in lymphedema was evaluated. In this report radionuclide lymphoscintigraphy was performed in 110 cases of clinically suspected lymphedema. A retrospective study method was used to analyze the imaging results. The typical pattern of lymphedema on radionuclide lymphoscintigraphy was summarized. It was found that the characteristics of lymphedema on radionuclide lymphoscintigraphy were diverse. The most common pattern was increased radiotracer accumulation in the soft tissue and lymphatic webs. Surgery and infection dominated as the causes of lymphedema in this study. It was concluded that radionuclide lymphoscintigraphy is a useful noninvasive method for diagnosing lymphedema. It is easy to operate and provides reliable results.