title: Dosimetric and clinical predictors of radiation-induced lung toxicity in esophageal carcinoma.
abstract: OBJECTIVE
  Radiation-induced lung toxicity occurs frequently in patients with esophageal carcinoma. This study aims to evaluate the clinical and three-dimensional dosimetric parameters associated with lung toxicity after radiotherapy for esophageal carcinoma.
  
  
  METHODS
  The records of 56 patients treated for esophageal carcinoma were reviewed. The Radiation Therapy Oncology Group criteria for grading of lung toxicity were followed. Spearman's correlation test, the chi-square test and logistic regression analyses were used for statistical analysis.
  
  
  RESULTS
  Ten of the 56 patients developed acute toxicity. The toxicity grades were grade 2 in 7 patients and grade 3 in 3 patients; none of the patients developed grade 4 or worse toxicity. One case of toxicity occurred during radiotherapy and 9 occurred 2 weeks to 3 months after radiotherapy. The median time was 2.0 months after radiotherapy. Fourteen patients developed late irradiated lung injury, 3 after 3.5 months, 7 after 9 months, and 4 after 14 months. Radiographic imaging demonstrated patchy consolidation (n = 5), atelectasis with parenchymal distortion (n = 6), and solid consolidation (n = 3). For acute toxicity, the irradiated esophageal volume, number of fields, and most dosimetric parameters were predictive. For late toxicity, chemotherapy combined with radiotherapy and other dosimetric parameters were predictive. No obvious association between the occurrence of acute and late injury was observed.
  
  
  CONCLUSIONS
  The percent of lung tissue receiving at least 25 Gy (V25), the number of fields, and the irradiated length of the esophagus can be used as predictors of the risk of acute toxicity. Lungs V30, as well as chemotherapy combined with radiotherapy, are predictive of late lung injury.
authors.affiliation: Department of Radiation Oncology, The Fourth Hospital of Hebei Medical University, Shijiazhuang,China. sczhu@heinfo.net
authors.forename: Shu-Chai
authors.initials: SC
authors.lastname: Zhu
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Shen
authors.forename: Zhi-Kun
authors.initials: ZK
authors.lastname: Liu
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.forename: Jing-Wei
authors.initials: JW
authors.lastname: Su
authors.forename: Yu-Xiang
authors.initials: YX
authors.lastname: Wang
mesh_terms: D000208:Acute Disease; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000532:radiotherapy* / Q000556:secondary; D002945:Cisplatin / Q000008:administration & dosage; D004307:Dose-Response Relationship, Radiation; D004334:Drug Administration Schedule; D004938:Esophageal Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D017567:Karnofsky Performance Status; D016015:Logistic Models; D008168:Lung / Q000473:pathology / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D011014:Pneumonia / Q000209:etiology*; D011237:Predictive Value of Tests; D011832:Radiation Injuries / Q000209:etiology*; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant; D020266:Radiotherapy, Conformal / Q000379:methods; D012189:Retrospective Studies; D012306:Risk; D013997:Time Factors
chemical_list: D002945:Cisplatin; D005472:Fluorouracil