title: Predictive value of dose-volume histogram parameters for predicting radiation pneumonitis after concurrent chemoradiation for lung cancer.
abstract: OBJECTIVE
  To clarify whether the percentage of pulmonary volume irradiated to >20 Gy (V20) is related to the incidence and grade of radiation pneumonitis (RP) in cases of lung cancer treated with concurrent chemoradiation.
  
  
  METHODS
  The subjects comprised 71 patients with lung cancer who were treated with conventionally fractionated definitive concurrent chemoradiation. The chemotherapy agents were carboplatin or cisplatin combined with taxane for most patients. Radiotherapy was delivered at 1.8-2.0 Gy fractions once daily to a total of 48-66 Gy (median 60). We analyzed the relation between RP grade and V20. Univariate and multivariate analyses were performed to assess patient- and treatment-related factors, including age, gender, smoking history, pulmonary function (forced expiratory volume in 1 s), tumor location (upper lobe vs. middle/lower lobe), chemotherapy regimen (platinum + taxane vs. other), total dose, overall radiation periods in addition to V20.
  
  
  RESULTS
  With a median follow-up of 7.5 months, an RP grade of 0, 1, 2, 3, and 5 was observed in 16, 35, 17, 1, and 2 patients, respectively; the corresponding mean V20 values were 20.1%, 22.0%, 26.3%, 27.0%, and 34.5%. The 6-month cumulative incidence of RP greater than Grade 2 was 8.7%, 18.3%, 51%, and 85% in patients with a V20 of <or=20%, 21-25%, 26-30%, and >or=31%, respectively (p <0.0001). According to both univariate and multivariate analyses, V20 was the only factor associated with RP of Grade 2 or greater.
  
  
  CONCLUSIONS
  The incidence and grade of RP are significantly related to the V20 value. Thus, V20 appears to be a factor that can be used to predict RP after concurrent chemoradiation for lung cancer.
authors.affiliation: Department of Radiology, Hyogo Medical Center for Adults, Akashi-city, Hyogo, Japan. tsuk@mub.biglobe.ne.jp
authors.forename: Kayoko
authors.initials: K
authors.lastname: Tsujino
authors.forename: Saeko
authors.initials: S
authors.lastname: Hirota
authors.forename: Masahiro
authors.initials: M
authors.lastname: Endo
authors.forename: Kayoko
authors.initials: K
authors.lastname: Obayashi
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Kotani
authors.forename: Miyako
authors.initials: M
authors.lastname: Satouchi
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Kado
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Takada
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000188:drug therapy / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D017564:Radiation Pneumonitis / Q000453:epidemiology*; D011879:Radiotherapy Dosage