Incremental Value of ¹³¹I SPECT/CT in the Management of Patients with Differentiated Thyroid Carcinoma

Abstract

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.

The Significance of 99mTc-MAA SPECT/CT Liver Perfusion Imaging in Treatment Planning for 90Y-Microsphere Selective Internal Radiation Treatment

“…In addition to anatomic referencing, the benefit of CT coregistration is based on the attenuation correction capabilities of CT (12). The positive impact of SPECT/CT in diagnosing benign and malignant diseases has been shown in different studies (13)(14)(15)(16)(17)(18)(19)(20).…”

Value of SPECT/CT in Cervical Vertebra Metastasis Mimicking Residual Thyroid Tissue on Planar I-131 Scan

“…In some studies, SPECT/CT was performed on only selected patients whose planar images showed inconclusive findings [11,12]. Chen et al [11] reported that SPECT/CT was of incremental value over planar I-131 WBS in increasing accuracy, reducing pitfalls and modifying therapy in 73.9% of patients with DTC. In this study, uncommon metastatic lesions were found in 9 of 66 patients with regard to SPECT/CT.…”

“…But the accurate localization of abnormal foci of activities is not possible usually because of the lack of anatomic landmarks. In addition, physiological I-131 uptake in the salivary glands, nose, mouth and residual thyroid tissue is also an important problem because some abnormal foci of activities can be hidden by these overlapping structures [8][9][10][11]. In some studies, SPECT/CT was performed on only selected patients whose planar images showed inconclusive findings [11,12].…”

“…In addition, physiological I-131 uptake in the salivary glands, nose, mouth and residual thyroid tissue is also an important problem because some abnormal foci of activities can be hidden by these overlapping structures [8][9][10][11]. In some studies, SPECT/CT was performed on only selected patients whose planar images showed inconclusive findings [11,12]. Chen et al [11] reported that SPECT/CT was of incremental value over planar I-131 WBS in increasing accuracy, reducing pitfalls and modifying therapy in 73.9% of patients with DTC.…”

2016 Russian clinical practice guidelines for differentiated thyroid cancer diagnosis and treatment

“…Сцинтиграфия всего тела [205][206][207][208][209][210][211][212][213][214][215][216] Рекомендация 42. У пациентов с био-химической ремиссией после РЙТ проведе-ние плановой СВТ не показано.…”