A study by Choi et al [7], which prospectively evaluated 109 patients with esophageal cancer, used a short-axis diameter of 8 mm for the determination of positive nodes and reported a sensitivity of 35% and specificity of 93% for CT. CT is limited in the evaluation of nodal metastatic disease because multiple studies have shown that nodal metastases often occur in small lymph nodes in patients with esophageal cancer. Foley et al [8] evaluated 112 patients with multiple modalities and reported an accuracy of 54.5%, a sensitivity of 55.4%, a sensitivity of 39.7%, and a specificity of 77.4% for CT. Foley et al [8] also reported that 82% of positive lymph nodes measured <6 mm. Similarly, Kajiyama et al [9] reported that two-thirds of 320 metastatic lymph nodes assessed by surgery were <5 mm, further reinforcing that preoperative anatomic imaging evaluation will have a limited role in the detection of nodal metastatic disease. In terms of clinical relevance, Bunting et al [10] prospectively studied 133 patients undergoing surgery and reported an N stage accuracy of 75.6%. Their conclusion was that staging accuracy of locoregional disease with respect to the neoadjuvant threshold was poor with all modalities, including CT, and could potentially lead to over- and undertreatment. The principle use of CT in the initial evaluation of patients with esophageal cancer is in detecting metastatic disease. CT has been compared with PET and FDG-PET/CT by several authors. Heeren et al [11] compared combined CT/esophageal US with PET and reported that sensitivity for distant nodal and systemic metastatic disease increased from 37% with CT/esophageal US to 78% with PET. Similarly, Hocazade et al [12] prospectively evaluated 91 patients with PET/CT and CT and reported that 47.3% of patients had metastases detected on PET/CT that were not detected by CT.
Staging and Follow up of Esophageal Cancer. A study by Choi et al [7], which prospectively evaluated 109 patients with esophageal cancer, used a short-axis diameter of 8 mm for the determination of positive nodes and reported a sensitivity of 35% and specificity of 93% for CT. CT is limited in the evaluation of nodal metastatic disease because multiple studies have shown that nodal metastases often occur in small lymph nodes in patients with esophageal cancer. Foley et al [8] evaluated 112 patients with multiple modalities and reported an accuracy of 54.5%, a sensitivity of 55.4%, a sensitivity of 39.7%, and a specificity of 77.4% for CT. Foley et al [8] also reported that 82% of positive lymph nodes measured <6 mm. Similarly, Kajiyama et al [9] reported that two-thirds of 320 metastatic lymph nodes assessed by surgery were <5 mm, further reinforcing that preoperative anatomic imaging evaluation will have a limited role in the detection of nodal metastatic disease. In terms of clinical relevance, Bunting et al [10] prospectively studied 133 patients undergoing surgery and reported an N stage accuracy of 75.6%. Their conclusion was that staging accuracy of locoregional disease with respect to the neoadjuvant threshold was poor with all modalities, including CT, and could potentially lead to over- and undertreatment. The principle use of CT in the initial evaluation of patients with esophageal cancer is in detecting metastatic disease. CT has been compared with PET and FDG-PET/CT by several authors. Heeren et al [11] compared combined CT/esophageal US with PET and reported that sensitivity for distant nodal and systemic metastatic disease increased from 37% with CT/esophageal US to 78% with PET. Similarly, Hocazade et al [12] prospectively evaluated 91 patients with PET/CT and CT and reported that 47.3% of patients had metastases detected on PET/CT that were not detected by CT.