The Role of MR Imaging in Detecting Nodal Disease in Thyroidectomy Patients with Rising Thyroglobulin Levels

• Published in: American journal of neuroradiology Vol. 30; no. 3; pp. 608 - 612
• Main Authors: Kaplan, S.L, Mandel, S.J, Muller, R, Baloch, Z.W, Thaler, E.R, Loevner, L.A
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oak Brook, IL Am Soc Neuroradiology 01-03-2009; American Society of Neuroradiology
• Subjects: Aged; Biological and medical sciences; Carcinoma, Papillary - radiotherapy; Carcinoma, Papillary - secondary; Carcinoma, Papillary - surgery; Combined Modality Therapy; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Female; Head & Neck; Humans; Investigative techniques, diagnostic techniques (general aspects); Iodine Radioisotopes - therapeutic use; Lymph Nodes - pathology; Lymphatic Metastasis; Magnetic Resonance Imaging; Male; Medical sciences; Middle Aged; Neck; Nervous system; Neurology; Postoperative Complications - blood; Postoperative Complications - pathology; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Retrospective Studies; Thyroglobulin - blood; Thyroid Neoplasms - pathology; Thyroid Neoplasms - radiotherapy; Thyroid Neoplasms - surgery; Thyroidectomy; Human; Nervous system diseases; Radiodiagnosis; Nuclear magnetic resonance imaging; Thyroidectomy
• ISSN: 0195-6108; 1936-959X
• DOI: 10.3174/ajnr.A1405

One of the dilemmas facing clinicians treating patients with thyroid cancer is the evaluation of postthyroidectomy patients with rising serum thyroglobulin levels and indeterminate or normal findings on neck sonography. In this study, we examine the role of MR imaging in this subgroup of patients.
We retrospectively reviewed MR images of patients with thyroid cancer with abnormal lymph nodes in the retropharyngeal and parapharyngeal spaces and determined the size and signal-intensity characteristics of these nodes. We reviewed patient charts for the following history: 1) thyroidectomy, 2) rising thyroglobulin levels, 3) iodine-131 radiation therapy, 4) neck dissection, and 5) pathology on neck sonography and chest CT. We reviewed pathology findings to determine if thyroid cancer metastases were present in these lymph nodes.
Eight patients had abnormal retropharyngeal space nodes, and 1 patient had a parapharyngeal space mass. Lymph nodes ranged from 7 to 25 mm. On MR imaging, 1 patient had a cystic node, 2 had complex nodes, and 6 had solid nodes. Eight patients had rising serum thyroglobulin levels and a history of thyroidectomy, radioiodine therapy, and neck dissection. Two of these patients had no pathologic nodes on sonography and normal findings on chest CT. Six patients had tissue sampling of their skull base node, and metastatic thyroid cancer was present in 5.
MR imaging of the neck should be considered in thyroidectomy patients with rising serum thyroglobulin levels and a history of radioiodine therapy and neck dissection. Radiologists should carefully examine the retropharyngeal and parapharyngeal spaces in these patients because nodal metastases may occur there more commonly than realized.