title: [Low dose volume histogram analysis of the lungs in prediction of acute radiation pneumonitis in patients with esophageal cancer treated with three-dimensional conformal radiotherapy].
abstract: OBJECTIVE
  To investigate the predictive value of low dose volume of the lung on acute radiation pneumonitis (RP) in patients with esophageal cancer treated with three-dimensional conformal radiotherapy (3D-CRT) only, and to analyze the relation of comprehensive parameters of the dose-volume V5, V20 and mean lung dose (MLD) with acute RP.
  
  
  METHODS
  Two hundred and twenty-two patients with esophageal cancer treated by 3D-CRT have been followed up. The V5-V30 and MLD were calculated from the dose-volume histogram system. The clinical factors and treatment parameters were collected and analyzed. The acute RP was evaluated according to the RTOG toxicity criteria.
  
  
  RESULTS
  The acute RP of grade 1, 2, 3 and 4 were observed in 68 (30.6%), 40 (18.0%), 8 (3.6%) and 1 (0.5%) cases, respectively. The univariate analysis of measurement data:The primary tumor length, radiation fields, MLD and lung V5-V30 had a significant relationship with the acute RP. The magnitude of the number of radiation fields, the volume of GTV, MLD and Lung V5-V30 had a significant difference in whether the ≥ grade 1 and ≥ grade 2 acute RP developed or not. Binary logistic regression analysis showed that MLD, Lung V5, V20 and V25 were independent risk factors of ≥ grade 1 acute RP, and the radiation fields, MLD and Lung V5 were independent risk factors of ≥ grade 2 acute RP. The ≥ grade 1 and ≥ grade 2 acute RP were significantly decreased when MLD less than 14 Gy, V5 and V20 were less than 60% and 28%,respectively. When the V20 ≤ 28%, the acute RP was significantly decreased in V5 ≤ 60% group. When the MLD was ≤ 14 Gy, the ≥ 1 grade acute RP was significantly decreased in the V5 ≤ 60% group. When the MLD was >14 Gy, the ≥ grade 2 acute RP was significantly decreased in the V5 ≤ 60% group.
  
  
  CONCLUSIONS
  The low dose volume of the lung is effective in predicting radiation pneumonitis in patients with esophageal cancer treated with 3D-CRT only. The comprehensive parameters combined with V5, V20 and MLD may increase the effect in predicting radiation pneumonitis.
authors: Department of Radiation Oncology, Hebei Medical University, Shijiazhaung, China. wbshen1979@sina.com
authors: Wen-bin
authors: WB
authors: Shen
authors: Shu-chai
authors: SC
authors: Zhu
authors: Hong-mei
authors: HM
authors: Gao
authors: You-mei
authors: YM
authors: Li
authors: Zhi-kun
authors: ZK
authors: Liu
authors: Juan
authors: J
authors: Li
authors: Jing-wei
authors: JW
authors: Su
authors: Jun
authors: J
authors: Wan
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy*; D004307:Dose-Response Relationship, Radiation; D004938:Esophageal Neoplasms / Q000532:radiotherapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008168:Lung / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D017564:Radiation Pneumonitis / Q000209:etiology* / Q000473:pathology; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000009:adverse effects*; D012189:Retrospective Studies