Vallbohmer et al [29] prospectively evaluated 119 patients with FDG-PET/CT 2 to 3 weeks after induction of neoadjuvant chemotherapy and found no significant association between major responders and FDG-PET/CT results; receiver operating characteristic analysis could not identify an SUV threshold to predict histomorphologic response, and there was no association between metabolic imaging and prognosis. Elliot et al [30] prospectively evaluated 100 patients with esophageal cancer who underwent FDG-PET/CT at 2 to 4 weeks after completion of neoadjuvant therapy and concluded FDG-PET/CT had poor prognostic value and clinical application for determining responders. Piessen et al [31] prospectively evaluated 46 patients with esophageal cancer who had FDG-PET/CT performed 4 to 6 weeks after completion of neoadjuvant therapy and concluded that FDG-PET/CT did not correlate with pathological response and long-term survival in patients with locally advanced esophageal cancer. Van Heijl et al [32] prospectively studied patients with esophageal cancer who had FDG- PET/CT at 2 weeks after the induction of chemotherapy and found FDG-PET/CT showed a statistically significant decrease in SUV in responders and correctly identified 58 of 64 responders and 18 of 36 nonresponders. The authors concluded that the low accuracy in detecting nonresponders did not justify using FDG-PET/CT for early discontinuation of neoadjuvant chemotherapy. FDG-PET/CT also has the potential to detect metastases that have developed in the interval after the induction of neoadjuvant therapy. A systematic review and meta-analysis performed by Kroese et al [33] evaluated 14 studies (1,110 patients) and found a pooled proportion of 8% of patients having interval metastases detected by FDG- PET/CT. The authors also reported an additional pooled proportion of 5% of patients who had false-positive concerning distant findings.
Staging and Follow up of Esophageal Cancer. Vallbohmer et al [29] prospectively evaluated 119 patients with FDG-PET/CT 2 to 3 weeks after induction of neoadjuvant chemotherapy and found no significant association between major responders and FDG-PET/CT results; receiver operating characteristic analysis could not identify an SUV threshold to predict histomorphologic response, and there was no association between metabolic imaging and prognosis. Elliot et al [30] prospectively evaluated 100 patients with esophageal cancer who underwent FDG-PET/CT at 2 to 4 weeks after completion of neoadjuvant therapy and concluded FDG-PET/CT had poor prognostic value and clinical application for determining responders. Piessen et al [31] prospectively evaluated 46 patients with esophageal cancer who had FDG-PET/CT performed 4 to 6 weeks after completion of neoadjuvant therapy and concluded that FDG-PET/CT did not correlate with pathological response and long-term survival in patients with locally advanced esophageal cancer. Van Heijl et al [32] prospectively studied patients with esophageal cancer who had FDG- PET/CT at 2 weeks after the induction of chemotherapy and found FDG-PET/CT showed a statistically significant decrease in SUV in responders and correctly identified 58 of 64 responders and 18 of 36 nonresponders. The authors concluded that the low accuracy in detecting nonresponders did not justify using FDG-PET/CT for early discontinuation of neoadjuvant chemotherapy. FDG-PET/CT also has the potential to detect metastases that have developed in the interval after the induction of neoadjuvant therapy. A systematic review and meta-analysis performed by Kroese et al [33] evaluated 14 studies (1,110 patients) and found a pooled proportion of 8% of patients having interval metastases detected by FDG- PET/CT. The authors also reported an additional pooled proportion of 5% of patients who had false-positive concerning distant findings.