Routine Chest Computed Tomography at Presentation Does Not Identify Distant Metastasis in cT1aN0 Papillary Thyroid Carcinoma

Background: Active surveillance is accepted as a first-line management for patients with low-risk papillary thyroid microcarcinoma (PTMC) without metastasis or extrathyroid extension. While the lung is the most frequent site of distant metastasis of papillary thyroid carcinomas (PTCs), it is unclear if chest computed tomography (CT) is necessary at the initiation of active surveillance. In our institution, we usually did not perform chest CT for candidates identified for active surveillance. However, routine preoperative chest CT for patients with thyroid cancers, including PTMCs, was standard practice. The present study aimed to evaluate the clinical value of chest CT for patients with PTMCs. Methods: We retrospectively reviewed preoperative chest CT images from 1000 consecutive patients (88.5% women; median age, 55 years) with cT1aN0 PTC who underwent surgery between January 2006 and May 2012 in our hospital. The median maximum size of PTMCs was 8 mm. Results: Abnormal findings were detected in 326 (32.6%) of the 1000 patients. Of these, 290 patients had presumed benign or inflammatory lesions of no clinical importance. In total, 36 patients (3.6%) were referred to specialized departments for further evaluation of the lesions, and 9 patients (0.9%) received invasive tests and/or treatments. Five patients (0.5%) benefited from the chest CT (lung cancer was detected in four, and a cardiac lesion was detected and treated in one), while the lesions in the other four patients were benign, not necessarily requiring treatment. The remaining 27 patents were followed for presumed benign or inflammatory lesions. Thus, none of the present 1000 patients was found with distant metastasis of thyroid cancer. Conclusions: Routine chest CT did not detect thyroid cancer lung metastasis in patients with PTMC. Thus, routine chest CT at the time of presentation is not required for patients with cT1aN0 PTCs.