title: Analysis of dose-volume parameters predicting radiation pneumonitis in patients with esophageal cancer treated with 3D-conformal radiation therapy or IMRT.
abstract: OBJECTIVE
  Multimodality therapy for esophageal cancer can cause various kinds of treatment-related sequelae, especially pulmonary toxicities. This prospective study aims to investigate the clinical and dosimetric parameters predicting lung injury in patients undergoing radiation therapy for esophageal cancer.
  
  
  METHODS
  Forty-five esophageal cancer patients were prospectively analyzed. The pulmonary toxicities (or sequelae) were evaluated by comparing chest X-ray films, pulmonary function tests and symptoms caused by pulmonary damage before and after treatment. All patients were treated with either three-dimensional radiotherapy (3DCRT) or with intensity-modulated radiotherapy (IMRT). The planning dose volume histogram was used to compute the lung volumes receiving more than 5, 10, 20 and 30 Gy (V5, V10, V20, V30) and mean lung dose.
  
  
  RESULTS
  V20 was larger in the IMRT group than in the 3DCRT group (p = 0.002). V20 (>15%) and V30 (>20%) resulted in a statistically significant increase in the occurrence of chronic pneumonitis (p = 0.03) and acute pneumonitis (p = 0.007), respectively.
  
  
  CONCLUSIONS
  The study signifies that a larger volume of lung receives lower doses because of multiple beam arrangement and a smaller volume of lung receives higher doses because of better dose conformity in IMRT plans. Acute pneumonitis correlates more with V30 values, whereas chronic pneumonitis was predominantly seen in patients with higher V20 values.
authors.affiliation: Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Centre, Sector 5, Rohini, New Delhi 110085, India. dr_gauravkumar@yahoo.com
authors.forename: Gaurav
authors.initials: G
authors.lastname: Kumar
authors.forename: Sheh
authors.initials: S
authors.lastname: Rawat
authors.forename: Abhishek
authors.initials: A
authors.lastname: Puri
authors.forename: Manoj Kumar
authors.initials: MK
authors.lastname: Sharma
authors.forename: Pranav
authors.initials: P
authors.lastname: Chadha
authors.forename: Anand Giri
authors.initials: AG
authors.lastname: Babu
authors.forename: Girigesh
authors.initials: G
authors.lastname: Yadav
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D004307:Dose-Response Relationship, Radiation; D004938:Esophageal Neoplasms / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D017564:Radiation Pneumonitis / Q000209:etiology*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D020266:Radiotherapy, Conformal / Q000009:adverse effects*; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects*; D012129:Respiratory Function Tests / Q000379:methods / Q000706:statistics & numerical data; D012720:Severity of Illness Index