title: Dosimetric comparison of 3-dimensional conformal and field-in-field radiotherapy techniques for the adjuvant treatment of early stage endometrial cancer.
abstract: BACKGROUND
  The purpose of this study is to compare field-in-field radiotherapy (FIF) with conformal radiotherapy (CRT) in terms of dosimetric benefits for early stage endometrial cancer patients.
  
  
  METHODS
  Ten consecutive early stage endometrial cancer patients who underwent adjuvant external beam radiotherapy were included in the study. For each patient, two different treatment plans were created. FIF and CRT plans were compared for doses in the planning target volume (PTV), the organ at risk (OAR) volumes including rectum, bladder, bowel, bilateral femurs and bone marrow, the dose homogeneity index, and the monitor unit counts required for the treatment.
  
  
  RESULTS
  The FIF technique significantly reduced the maximum dose of the PTV, rectum, bladder, bowel, left femur, right femur and bone marrow (p values were: <0.001, 0.031, 0.003, <0.001, 0.001, 0.001 and <0.001 respectively). When the OAR volumes irradiated with >30 and >45 Gy were compared, the results were in favor of the FIF technique. The volumes of rectum, bladder, bowel, left femur, right femur and bone marrow receiving more than the prescription dose of 45 Gy were significantly reduced with FIF technique (p values were 0.016, 0.039, 0.01, 0.04, 0.037 and 0.01 respectively). The dose homogeneity index (DHI) was significantly improved with FIF technique (p < 0.001).
  
  
  CONCLUSIONS
  FIF allowed more homogeneous dose distribution in the PTV and reduced the doses received by OAR. Considering the lower maximum doses in the OAR and PTV, FIF technique seems to be more advantageous than CRT during adjuvant radiotherapy for early stage endometrial cancer patients.
authors.affiliation: Selcuk University, Faculty of Medicine, Department of Radiation Oncology, 42075 Konya, Turkey. Electronic address: guler.aydinyavas@gmail.com.
authors.forename: Guler
authors.initials: G
authors.lastname: Yavas
authors.forename: Cagdas
authors.initials: C
authors.lastname: Yavas
authors.forename: Hilal
authors.initials: H
authors.lastname: Acar
authors.forename: Ahmet
authors.initials: A
authors.lastname: Buyukyoruk
authors.forename: Gokcen
authors.initials: G
authors.lastname: Cobanoglu
authors.forename: Ozlem Secilmis
authors.initials: OS
authors.lastname: Kerimoglu
authors.forename: Ozlem
authors.initials: O
authors.lastname: Yavas
authors.forename: Cetin
authors.initials: C
authors.lastname: Celik
mesh_terms: D000368:Aged; D016889:Endometrial Neoplasms / Q000473:pathology* / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D058958:Organs at Risk / Q000528:radiation effects; D011874:Radiometry; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects; D020266:Radiotherapy, Conformal / Q000009:adverse effects / Q000379:methods*