title: Tangential beam IMRT versus tangential beam 3D-CRT of the chest wall in postmastectomy breast cancer patients: a dosimetric comparison.
abstract: BACKGROUND
  This study evaluates the dose distribution of reversed planned tangential beam intensity modulated radiotherapy (IMRT) compared to standard wedged tangential beam three-dimensionally planned conformal radiotherapy (3D-CRT) of the chest wall in unselected postmastectomy breast cancer patients
  
  
  METHODS
  For 20 unselected subsequent postmastectomy breast cancer patients tangential beam IMRT and tangential beam 3D-CRT plans were generated for the radiotherapy of the chest wall. The prescribed dose was 50 Gy in 25 fractions. Dose-volume histograms were evaluated for the PTV and organs at risk. Parameters of the dose distribution were compared using the Wilcoxon matched pairs test.
  
  
  RESULTS
  Tangential beam IMRT statistically significantly reduced the ipsilateral mean lung dose by an average of 21% (1129 cGy versus 1437 cGy). In all patients treated on the left side, the heart volume encompassed by the 70% isodose line (V70%; 35 Gy) was reduced by an average of 43% (5.7% versus 10.6%), and the mean heart dose by an average of 20% (704 cGy versus 877 cGy). The PTV showed a significantly better conformity index with IMRT; the homogeneity index was not significantly different.
  
  
  CONCLUSIONS
  Tangential beam IMRT significantly reduced the dose-volume of the ipsilateral lung and heart in unselected postmastectomy breast cancer patients.
authors.affiliation: Department of Radiation Oncology, Saad Specialist Hospital, Saudi Arabia. vrudat@saad.com.sa
authors.forename: Volker
authors.initials: V
authors.lastname: Rudat
authors.forename: Abdul Aziz
authors.initials: AA
authors.lastname: Alaradi
authors.forename: Adel
authors.initials: A
authors.lastname: Mohamed
authors.forename: Khaled
authors.initials: K
authors.lastname: Ai-Yahya
authors.forename: Saleh
authors.initials: S
authors.lastname: Altuwaijri
mesh_terms: D001943:Breast Neoplasms / Q000532:radiotherapy* / Q000601:surgery*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D015412:Mastectomy, Segmental; D058958:Organs at Risk; D011829:Radiation Dosage; D011874:Radiometry; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D018714:Radiotherapy, Adjuvant; D020266:Radiotherapy, Conformal / Q000295:instrumentation / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000295:instrumentation / Q000379:methods*; D012189:Retrospective Studies; D035441:Thoracic Wall / Q000528:radiation effects