title: Para-aortic and pelvic extended-field radiotherapy for advanced-stage uterine cancer: dosimetric and toxicity comparison between the four-field box and intensity-modulated techniques.
abstract: BACKGROUND
  In patients with advanced-stage endometrial carcinoma (eca), extended-field radiotherapy (efrt) is traditionally delivered by the 3-dimensional conformal (3d-crt) 4-field box technique. In recent years, the use of intensity-modulated radiotherapy (imrt) in gynecologic cancers has increased. We compared the delivery of efrt by the 3d-crt and contemporary imrt techniques.
  
  
  METHODS
  After surgical staging and adjuvant chemotherapy in 38 eca patients, efrt was delivered by either imrt or 3d-crt. Doses to the organs at risk, side effects, and outcomes were compared between the techniques.
  
  
  RESULTS
  Of the 38 eca patients, 33 were stage iiic, and 5 were stage ivb. In the imrt group, maximal doses to rectum, small intestine, and bladder were significantly higher, and mean dose to bladder was lower (p < 0.0001). Most acute gastrointestinal, genitourinary, and hematologic side effects were grade i or ii and were comparable between the groups. In long-term follow-up, only grade 1 cystitis at 3 months was statistically higher in the imrt patients. No grade iii or iv gastrointestinal or genitourinary toxicities were observed. No statistically significant differences in overall and disease-free survival or recurrence rates were observed between the techniques.
  
  
  CONCLUSIONS
  In advanced eca patients, imrt is a safe and effective technique for delivering efrt to the pelvis and para-aortic region, and it is comparable to the 3d-crt 4-field box technique in both side effects and efficacy. For centres in which imrt is not readily available, 3d-crt is a valid alternative.
authors.affiliation: Division of Gynecologic Oncology, Segal Cancer Centre, Jewish General Hospital, McGill University, Montreal, QC;
authors.forename: A
authors.initials: A
authors.lastname: Rabinovich
authors.affiliation: Division of Radiation Oncology, Segal Cancer Centre, Jewish General Hospital, McGill University, Montreal, QC;
authors.forename: L
authors.initials: L
authors.lastname: Bernard
authors.affiliation: Department of Oncology, Division of Cancer Epidemiology, McGill University, Montreal, QC.
authors.forename: A V
authors.initials: AV
authors.lastname: Ramanakumar
authors.affiliation: Division of Radiation Oncology, Segal Cancer Centre, Jewish General Hospital, McGill University, Montreal, QC;
authors.forename: G
authors.initials: G
authors.lastname: Stroian
authors.affiliation: Division of Gynecologic Oncology, Segal Cancer Centre, Jewish General Hospital, McGill University, Montreal, QC;
authors.forename: W H
authors.initials: WH
authors.lastname: Gotlieb
authors.affiliation: Division of Gynecologic Oncology, Segal Cancer Centre, Jewish General Hospital, McGill University, Montreal, QC;
authors.forename: S
authors.initials: S
authors.lastname: Lau
authors.affiliation: Division of Radiation Oncology, Segal Cancer Centre, Jewish General Hospital, McGill University, Montreal, QC;
authors.forename: B
authors.initials: B
authors.lastname: Bahoric
keywords: 3-dimensional conformal 4-field box technique; Extended-field radiotherapy; intensity-modulated radiotherapy