Association of Clinical and Dosimetric Factors with Postoperative Pulmonary Complications in Esophageal Cancer Patients Receiving Intensity-Modulated Radiation Therapy and Concurrent Chemotherapy Followed by Thoracic Esophagectomy

To investigate the association between clinical/dosimetric factors and postoperative pulmonary complications (PPC) in esophageal cancer patients undergoing neoadjuvant chemotherapy and intensity-modulated radiation therapy (IMRT) followed by thoracic esophagectomy. The data from 52 patients receiving combined modality treatment were analyzed. Chemotherapy was taxane-based in 43 and 5-fluorouracil-based in 9 patients. IMRT (40-45 Gy, median 40 Gy, at 1.8-2 Gy per fraction) was given using a 3-5-beam arrangement. Surgery consisted of open or minimally invasive esophagectomy. The dosimetric parameters were generated from lung dose-volume histogram computed by the treatment planning software. PPC was defined as pneumonia or respiratory insufficiency within 30 days after surgery. Statistical correlations were analyzed between clinical/dosimetric factors and PPC. The incidence of PPC was 34.6%. No patients died of PPC. Two patients (3.8%) became ventilator dependent. In univariate analyses, preoperative forced expiratory volume in 1 s (FEV1) and forced vital capacity before surgery were significantly associated with PPC (P = 0.02 and 0.04, respectively). None of the dosimetric factors predicted development of PPC. For the 51 patients undergoing right transthoracic surgery, higher absolute spared volume of the right lung receiving 15 Gy was significantly associated with PPC (P = 0.03). In multivariate analysis, preoperative FEV1 was the only independent factor associated with PPC (P = 0.002). Preoperative rather than prechemoradiation FEV1 predicts development of PPC. Reducing the absolute volume of the right lung that is irradiated might decrease the risk of PPC for patients receiving right transthoracic surgery.