title: Retrospective imaging study on the diagnosis of pathological false positive iodine-131 scans in patients with thyroid cancer.
abstract: Iodine-131 (I-131) therapy and post-therapy I-131 scanning are essential in the management of differentiated thyroid cancer (DTC). However, pathological false positive I-131 scans can lead to misdiagnosis and inappropriate I-131 treatment. This retrospective study aimed to investigate the best imaging modality for the diagnosis of pathological false positive I-131 scans in a DTC patient cohort, and to determine its incidence. DTC patient data archived from January 2008 to January 2010 was retrieved. Post-therapeutic I-131 scans were conducted and interpreted. The imaging modalities of magnetic resonance imaging (MRI), computed tomography and ultrasonography were applied and compared to check all suspected lesions. Biopsy or needle aspiration was conducted for patients who consented to the acquisition of histopathological confirmation. Data for 156 DTC patients were retrieved. Only 6 cases of pathological false-positives were found among these (incidence, 3.85%), which included 3 cases of thymic hyperplasia in the mediastinum, 1 case of pleomorphic adenoma in the parapharyngeal space and 1 case of thyroglossal duct cyst in the neck. MRI was demonstrated as the best imaging modality for diagnosis due to its superior soft tissue resolution. However, no imaging modality was able to identify the abdominal false positive-lesions observed in 2 cases, one of whom also had thymic hyperplasia. In conclusion, pathological false positive I-131 scans occurred with an incidence of 3.85%. MRI was the best imaging modality for diagnosing these pathological false-positives.
authors.affiliation: Department of Nuclear Medicine, Tianjin Medical University General Hospital, Heping, Tianjin 300052, P.R. China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Jia
authors.affiliation: Department of Nuclear Medicine, Tianjin Medical University General Hospital, Heping, Tianjin 300052, P.R. China.
authors.forename: Zhaowei
authors.initials: Z
authors.lastname: Meng
authors.affiliation: Department of Nuclear Medicine, Tianjin Medical University General Hospital, Heping, Tianjin 300052, P.R. China.
authors.forename: Jian
authors.initials: J
authors.lastname: Tan
authors.affiliation: Department of Nuclear Medicine, Tianjin Medical University General Hospital, Heping, Tianjin 300052, P.R. China.
authors.forename: Guizhi
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Department of Nuclear Medicine, Tianjin Medical University General Hospital, Heping, Tianjin 300052, P.R. China.
authors.forename: Yajing
authors.initials: Y
authors.lastname: He
authors.affiliation: Department of Radiology, Tianjin Medical University General Hospital, Heping, Tianjin 300052, P.R. China.
authors.forename: Haoran
authors.initials: H
authors.lastname: Sun
authors.affiliation: Department of Radiology, Tianjin Medical University General Hospital, Heping, Tianjin 300052, P.R. China.
authors.forename: Chunshui
authors.initials: C
authors.lastname: Yu
authors.affiliation: Department of Radiology, Tianjin Medical University General Hospital, Heping, Tianjin 300052, P.R. China.
authors.forename: Dong
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Nuclear Medicine, Tianjin Medical University General Hospital, Heping, Tianjin 300052, P.R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
authors.affiliation: Department of Nuclear Medicine, Tianjin Medical University General Hospital, Heping, Tianjin 300052, P.R. China.
authors.forename: Renfei
authors.initials: R
authors.lastname: Wang
authors.affiliation: Department of Nuclear Medicine, Tianjin Medical University General Hospital, Heping, Tianjin 300052, P.R. China.
authors.forename: Shen
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Nuclear Medicine, Tianjin Medical University General Hospital, Heping, Tianjin 300052, P.R. China.
authors.forename: Xue
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Nuclear Medicine, Tianjin Medical University General Hospital, Heping, Tianjin 300052, P.R. China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Nuclear Medicine, Tianjin Medical University General Hospital, Heping, Tianjin 300052, P.R. China.
authors.forename: Tianpeng
authors.initials: T
authors.lastname: Hu
authors.affiliation: Department of Nuclear Medicine, Tianjin Medical University General Hospital, Heping, Tianjin 300052, P.R. China.
authors.forename: N A
authors.initials: NA
authors.lastname: Liu
authors.affiliation: Department of Nuclear Medicine, Tianjin Medical University General Hospital, Heping, Tianjin 300052, P.R. China.
authors.forename: Arun
authors.initials: A
authors.lastname: Upadhyaya
keywords: differentiated thyroid cancer; iodine-131 scan; magnetic resonance imaging; pathological false positive