title: Transforming growth factor-beta-1 is a serum biomarker of radiation-induced pneumonitis in esophageal cancer patients treated with thoracic radiotherapy: preliminary results of a prospective study.
abstract: OBJECTIVE
  To examine the relationship between cytokine levels of transforming growth factor-beta-1 (TGF-β1), interleukin-1 beta (IL-1β), and angiotensin-converting enzyme (ACE) in the plasma of esophageal carcinoma patients and radiation-induced pneumonitis (RP).
  
  
  METHODS
  Sixty-three patients with esophageal carcinoma were treated with three-dimensional conformal radiotherapy (RT) using the Elekta Precise treatment planning system with a prescribed dose of 50-70 Gy. Dose-volume histograms were collected from three-dimensional conformal RT to determine the volume percentage of the lung received V5, V10, V20, and the normal tissue complication probability. RP was diagnosed based on computed tomography imaging, respiratory symptoms, and signs. The severity of radiation-induced lung toxicity was determined using the Lent-Soma scale defined by the Radiation Therapy Oncology Group. Plasma samples obtained before RT, during RT (at 40 Gy), and at 1 day, 1 month, and 3 months after RT were assayed for TGF-β1, IL-1β, and ACE levels by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  From the 63 patients, 17 (27%) developed RP, and 13 (21%) had RP of grade I and four (6%) had grade II or higher. We found plasma TGF-β1 levels were elevated in the patients that had RP when compared with the other 46 patients who did not have RP. The plasma IL-1β levels were not changed. The ACE levels were significantly lower in the 17 patients with RP compared to the 46 patients without RP throughout the RT. As expected, RP is associated with a higher dose of irradiation (>60 Gy); no other factors, including dose-volume histogram, age, sex, smoking status, location of tumor, and methods of treatment, are associated with RP.
  
  
  CONCLUSIONS
  Elevated plasma TGF-β1 levels can be used as a marker for RP.
authors.affiliation: Radiation Oncology Department, Henan University of Science and Technology, Luoyang, People's Republic of China.
authors.forename: Jingxia
authors.initials: J
authors.lastname: Li
authors.affiliation: Radiation Oncology Department, Henan University of Science and Technology, Luoyang, People's Republic of China.
authors.forename: Shuangfeng
authors.initials: S
authors.lastname: Mu
authors.affiliation: Radiation Oncology Department, Henan University of Science and Technology, Luoyang, People's Republic of China.
authors.forename: Lixiang
authors.initials: L
authors.lastname: Mu
authors.affiliation: Radiation Oncology Department, Henan University of Science and Technology, Luoyang, People's Republic of China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Radiation Oncology Department, Henan University of Science and Technology, Luoyang, People's Republic of China.
authors.forename: Ranran
authors.initials: R
authors.lastname: Pang
authors.affiliation: Department of Oncology, the First Affiliated Hospital, Henan University of Science and Technology, Luoyang, People's Republic of China.
authors.forename: Shegan
authors.initials: S
authors.lastname: Gao
keywords: ACE; IL-1β; TGF-β1; esophageal carcinoma; radiation-induced pneumonitis