title: Postoperative radiation therapy following the incomplete resection of a non-small cell lung cancer.
abstract: OBJECTIVE
  To review the results of postoperative radiation therapy (PORT) for residual non-small cell lung cancer (NSCLC) following surgical resection and evaluate multiple clinicopathologic prognostic factors.
  
  
  METHODS
  A total of 58 patients, who completed scheduled PORT for positive resection margin, among 658 patients treated with PORT from January 2001 to November 2011 were retrospectively analyzed. Radiation therapy was started at 4 to 6 weeks after surgery. Chemotherapy was also administered to 35 patients, either sequentially or concurrently with PORT.
  
  
  RESULTS
  The median age of patients was 63 years (range, 40 to 82 years). The postoperative pathological stage I NSCLC was diagnosed in 10 (17.2%), stage II in 18 (31.0%), and stage III in 30 patients (51.7%). Squamous cell carcinoma was identified in 43, adenocarcinoma in 10, large cell in 1, others in 4 patients. Microscopic residual disease (R1) was diagnosed in 55 patients (94.8%), and the remaining three patients were diagnosed with gross residual disease (R2). The median dose of PORT was 59.4 Gy (range, 50.0 to 64.8 Gy). Chemotherapy was administered to 35 patients (60%), and the median follow-up time was 22.0 months (range, 6.0 to 84.0 months). The 3-year locoregional relapse-free survival and distant metastasis-free survival rates were 82.1% and 52.9%, respectively. The median overall survival was 23.8 months (range, 6.0 to 84.1 months), and the 3-year overall survival rate was 58.2%. Chemotherapy did not influence the failure pattern or survival outcome.
  
  
  CONCLUSIONS
  PORT is an effective modality for improving local tumor control in incompletely resected NSCLC patients. Major failure pattern was distant metastasis despite chemotherapy.
authors: Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Jaehyeon
authors: J
authors: Park
authors: Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Si Yeol
authors: SY
authors: Song
authors: Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Su Ssan
authors: SS
authors: Kim
authors: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Sang-We
authors: SW
authors: Kim
authors: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Woo Sung
authors: WS
authors: Kim
authors: Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Seung-Il
authors: SI
authors: Park
authors: Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Dong Kwan
authors: DK
authors: Kim
authors: Department of Thoracic and Cardiovascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Yong-Hee
authors: YH
authors: Kim
authors: Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Jongmoo
authors: J
authors: Park
authors: Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Sang-Wook
authors: SW
authors: Lee
authors: Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Jong Hoon
authors: JH
authors: Kim
authors: Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Seung Do
authors: SD
authors: Ahn
authors: Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Eun Kyung
authors: EK
authors: Choi
keywords: Microscopic residual disease; Non-small-cell lung carcinoma; Postoperative radiotherapy; R1 resection