title: Patterns of failure and local control after intraoperative electron boost radiotherapy to the presacral space in combination with total mesorectal excision in patients with locally advanced rectal cancer.
abstract: OBJECTIVE
  To evaluate local control and patterns of failure in patients treated with intraoperative electron beam radiotherapy (IOERT) after total mesorectal excision (TME), to appraise the effectiveness of intraoperative target definition.
  
  
  METHODS
  We analyzed the outcome of 243 patients with rectal cancer treated with IOERT (median dose, 10 Gy) after TME. Eighty-eight patients received neoadjuvant and 122 patients adjuvant external beam radiotherapy (EBRT) (median dose, 41.4 Gy), and in 88% simultaneous chemotherapy was applied. Median follow-up was 59 months.
  
  
  RESULTS
  Local failure was observed in 17 patients (7%), resulting in a 5-year local control rate of 92%. Only complete resection and absence of nodal involvement correlated positively with local control. Considering IOERT fields, seven infield recurrences were seen in the presacral space, resulting in a 5-year local control rate of 97%. The remaining local relapses were located as follows: retrovesical/retroprostatic (5), anastomotic site (2), promontorium (1), ileocecal (1), and perineal (1).
  
  
  CONCLUSIONS
  Intraoperative electron beam radiotherapy as part of a multimodal treatment approach including TME is a highly effective regimen to prevent local failure. The presacral space remains the site of highest risk for local failure, but IOERT can decrease the percentage of relapses in this area.
authors.affiliation: Department of Radiation Oncology, University of Heidelberg, Heidelberg, Germany.
authors.forename: Falk
authors.initials: F
authors.lastname: Roeder
authors.forename: Martina
authors.initials: M
authors.lastname: Treiber
authors.forename: Susanne
authors.initials: S
authors.lastname: Oertel
authors.forename: Julien
authors.initials: J
authors.lastname: Dinkel
authors.forename: Carmen
authors.initials: C
authors.lastname: Timke
authors.forename: Angela
authors.initials: A
authors.lastname: Funk
authors.forename: Helena
authors.initials: H
authors.lastname: Garcia-Huttenlocher
authors.forename: Marc
authors.initials: M
authors.lastname: Bischof
authors.forename: Jürgen
authors.initials: J
authors.lastname: Weitz
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Harms
authors.forename: Frank W
authors.initials: FW
authors.lastname: Hensley
authors.forename: Markus W
authors.initials: MW
authors.lastname: Buchler
authors.forename: Jürgen
authors.initials: J
authors.lastname: Debus
authors.forename: Robert
authors.initials: R
authors.lastname: Krempien
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004583:Electrons / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control*; D018714:Radiotherapy, Adjuvant / Q000379:methods; D012004:Rectal Neoplasms / Q000532:radiotherapy* / Q000601:surgery*; D017211:Treatment Failure