title: Intraoperative radiation therapy with the photon radiosurgery system in locally advanced and recurrent rectal cancer: retrospective review of the Cleveland clinic experience.
abstract: BACKGROUND
  Patients with locally advanced or recurrent rectal cancer often require multimodality treatment. Intraoperative radiation therapy (IORT) is a focal approach which aims to improve local control.
  
  
  METHODS
  We retrospectively reviewed 42 patients treated with IORT following definitive resection of a locally advanced or recurrent rectal cancer from 2000-2009. All patients were treated with the Intrabeam® Photon Radiosurgery System (PRS). A dose of 5 Gy was prescribed to a depth of 1 cm (surface dose range: 13.4-23.1, median: 14.4 Gy). Median survival times were calculated using Kaplan-Meier analysis.
  
  
  RESULTS
  Of 42 patients, 32 had recurrent disease (76%) while 10 had locally advanced disease (24%). Eighteen patients (43%) had tumors fixed to the sidewall. Margins were positive in 19 patients (45%). Median follow-up after IORT was 22  months (range 0.2-101). Median survival time after IORT was 34 months. The 3-year overall survival rate was 49% (43% for recurrent and 65% for locally advanced patients). Local recurrence was evaluable in 34 patients, of whom 32% failed. The 1-year local recurrence rate was 16%. Distant metastasis was evaluable in 30 patients, of whom 60% failed. The 1-year distant metastasis rate was 32%. No intraoperative complications were attributed to IORT. Median duration of IORT was 35 minutes (range: 14-39). Median discharge time after surgery was 7 days (range: 2-59). Hydronephrosis after IORT occurred in 10 patients (24%), 7 of whom had documented concomitant disease recurrence.
  
  
  CONCLUSIONS
  The Intrabeam® PRS appears to be a safe technique for delivering IORT in rectal cancer patients. IORT with PRS marginally increased operative time, and did not appear to prolong hospitalization. Our rates of long-term toxicity, local recurrence, and survival rates compare favorably with published reports of IORT delivery with other methods.
authors: Department of Radiation Oncology, Cleveland Clinic, Cleveland, OH 44195, USA.
authors: Susan
authors: S
authors: Guo
authors: Chandana A
authors: CA
authors: Reddy
authors: Matthew
authors: M
authors: Kolar
authors: Neil
authors: N
authors: Woody
authors: Arul
authors: A
authors: Mahadevan
authors: F Christopher
authors: FC
authors: Deibel
authors: David W
authors: DW
authors: Dietz
authors: Feza H
authors: FH
authors: Remzi
authors: John H
authors: JH
authors: Suh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D017785:Photons / Q000627:therapeutic use*; D016634:Radiosurgery / Q000379:methods*; D011878:Radiotherapy / Q000379:methods*; D012004:Rectal Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D012189:Retrospective Studies; D055815:Young Adult