title: A novel dynamic field-matching technique for treatment of patients with para-aortic node-positive cervical cancer: Clinical experience.
abstract: OBJECTIVE
  To report outcomes for patients with para-aortic lymph node positive cervical cancer treated with a dynamic field-matching technique.
  
  
  BACKGROUND
  PET staging of cervical cancer has increased identification of patients with para-aortic lymph node metastasis. IMRT enables dose escalation in this area, but matching IMRT fields with traditional whole pelvis fields presents a challenge.
  
  
  METHODS
  From 2003 to 2012, 20 patients with cervical cancer and para-aortic lymph node metastasis were treated utilizing the dynamic field-matching technique. As opposed to single-isocenter half-beam junction techniques, this technique employs wedge-shaped dose junctions for the abutment of fields. We reviewed the records of all patients who completed treatment with the technique and abstracted treatment, toxicity, and disease-related outcome data for analysis.
  
  
  RESULTS
  Median prescribed dose to the whole pelvis field was 45 Gy and para-aortic IMRT field 50.4 Gy. All but 3 patients underwent HDR (13 pts) or LDR (4 pts) brachytherapy. All patients developed lower GI toxicity; 10 grade 1, 9 grade 2, and 1 grade 4 (enterovaginal fistula). Median DFS was 12.4 months with 1 and 2-year DFS 60.0% and 38.1%. One-year OS was 83.7% and 2-year OS, 64.4%. A total of 10 patients developed recurrence; none occurred at the matched junction.
  
  
  CONCLUSIONS
  The dynamic field-matching technique provides a means for joining conventional whole pelvis fields and para-aortic IMRT fields that substantially reduces dose deviations at the junction due to field mismatch. Treatment with the dynamic matching technique is simple, effective, and tolerated with no apparent increase in toxicity.
authors.affiliation: Department of Radiation Oncology, University of Alabama-Birmingham, Birmingham, AL, USA.
authors.forename: Craig
authors.initials: C
authors.lastname: Baden
authors.affiliation: Department of Radiation Oncology, University of Alabama-Birmingham, Birmingham, AL, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Whitley
authors.affiliation: Department of Radiation Oncology, University of Alabama-Birmingham, Birmingham, AL, USA.
authors.forename: Javier
authors.initials: J
authors.lastname: López-Araujo
authors.affiliation: Department of Radiation Oncology, University of Alabama-Birmingham, Birmingham, AL, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Popple
authors.affiliation: Department of Radiation Oncology, University of Alabama-Birmingham, Birmingham, AL, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Duan
authors.affiliation: Department of Radiation Oncology, University of Alabama-Birmingham, Birmingham, AL, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Kim
keywords: Cervical cancer; IMRT; Treatment planning