Postchemoradiotherapy Positron Emission Tomography For Predicting Survival In Patients With Esophageal Cancer

To correlate pre-chemoradiotherapy (preCRT) and postchemoradiotherapy (postCRT) gross tumor volume (GTV) and metabolic tumor volume (MTV) on positron emission tomography (PET) scanning with survival in patients who receive chemoradiation for esophageal cancer. The medical records of 41 patients with histologically confirmed stage I to IVA esophageal cancer treated with chemoradiation with or without surgical resection were reviewed. Thirty patients had adenocarcinoma (73%) and 11 patients had squamous cell carcinoma (27%). Twenty-four patients were treated with preoperative chemoradiation (59%), and 17 patients were treated with definitive chemoradiation (41%). Pre and postchemoradiotherapy PET scans were contoured for GTV. The MTV was measured using three different minimum standardized uptake value (SUV) thresholds, 2 (MTV2), 2.5 (MTV2.5), and 3 (MTV3). Prognostic variables such as age at diagnosis, gender, histology, and endoscopic ultrasound (EUS) TNM staging were collected. Treatment parameters such as radiation dosage and chemotherapy regimen were also examined. These variables were correlated with post-treatment GTV, MTV, maximum SUV, mean SUV, surgical TNM staging (in patients who underwent resection), and survival. There was no correlation of MTV2 (p = 0.12), MTV2.5 (p = 0.5), MTV3 (p = 0.5), GTV (p = 0.16), or maximum SUV (p = 0.9) on preCRT PET with survival. Increased postCRT GTV (p = 0.025) was found to be significantly associated with decreased survival. The MTV2 (p = 0.029), MTV2.5 (p = 0.035), and MTV3 (p = 0.04) all were associated with survival. The change in SUV, MTV, or GTV between the preCRT and postCRT PET scans did not correlate with survival. Our results show that the postCRT PET can be useful to predict prognosis in patients who complete chemoradiation for esophageal cancer. PET could possibly be used to determine which patients may require intensified therapy. Both the postCRT GTV and MTV were associated with survival.