title: Intraoperative electron radiation therapy (IOERT) in patients with locally recurrent renal cell carcinoma.
abstract: BACKGROUND
  To analyze our experience with intraoperative electron radiation therapy (IOERT) followed by moderate doses of external beam radiation therapy (EBRT) in patients with locally recurrent renal cell carcinoma.
  
  
  METHODS
  From 1992 to 2010, 17 patients with histologically proven, locally recurrent renal cell carcinoma (median tumor size 7 cm) were treated by surgery and IOERT with a median dose of 15 Gy. All patients met the premise of curative intent including 7 patients with oligometastases at the time of recurrent surgery, which were resected and/or irradiated. The median time interval from primary surgery to local recurrence was 26 months. Eleven patients received additional 3D-conformal EBRT with a median dose of 40 Gy.
  
  
  RESULTS
  Surgery resulted in free but close margins in 6 patients (R0), while 9 patients suffered from microscopic (R1) and 2 patients from macroscopic (R2) residual disease. After a median follow-up of 18 months, two local recurrences were observed, resulting in an actuarial 2-year local control rate of 91%. Eight patients developed distant failures, predominantly to liver and bone, resulting in an actuarial 2-year progression free survival of 32%. An improved PFS rate was found in patients with a larger time interval between initial surgery and recurrence (> 26 months). The actuarial 2-year overall survival rate was 73%. Lower histological grading (G1/2) was the only factor associated with improved overall survival. Perioperative complications were found in 4 patients. No IOERT specific late toxicities were observed.
  
  
  CONCLUSIONS
  Combination of surgery, IOERT and EBRT resulted in high local control rates with low toxicity in patients with locally recurrent renal cell cancer despite an unfavorable surgical outcome in the majority of patients. However, progression-free and overall survival were still limited due to a high distant failure rate, indicating the need for intensified systemic treatment especially in patients with high tumor grading and short interval to recurrence.
authors.affiliation: Department of Radiation Oncology, University of Heidelberg, Im Neuenheimer Feld 400 Heidelberg 69120, Germany. gregor.habl@med.uni-heidelberg.de.
authors.forename: Gregor
authors.initials: G
authors.lastname: Habl
authors.forename: Matthias
authors.initials: M
authors.lastname: Uhl
authors.forename: Frank
authors.initials: F
authors.lastname: Hensley
authors.forename: Sascha
authors.initials: S
authors.lastname: Pahernik
authors.forename: Juergen
authors.initials: J
authors.lastname: Debus
authors.forename: Falk
authors.initials: F
authors.lastname: Röder
mesh_terms: D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000473:pathology* / Q000532:radiotherapy* / Q000601:surgery; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D004583:Electrons / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D007668:Kidney / Q000528:radiation effects; D007680:Kidney Neoplasms / Q000473:pathology* / Q000532:radiotherapy* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000532:radiotherapy; D011878:Radiotherapy / Q000379:methods; D020266:Radiotherapy, Conformal / Q000379:methods; D012008:Recurrence; D012189:Retrospective Studies; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome