title: Outcomes in a multi-institutional cohort of patients treated with intraoperative radiation therapy for advanced or recurrent renal cell carcinoma.
abstract: OBJECTIVE
  This study aimed to analyze outcomes in a multi-institutional cohort of patients with advanced or recurrent renal cell carcinoma (RCC) who were treated with intraoperative radiation therapy (IORT).
  
  
  METHODS
  Between 1985 and 2010, 98 patients received IORT for advanced or locally recurrent RCC at 9 institutions. The median follow-up time for surviving patients was 3.5 years. Overall survival (OS), disease-specific survival (DSS), and disease-free survival (DFS) were estimated with the Kaplan-Meier method. Chained imputation accounted for missing data, and multivariate Cox hazards regression tested significance.
  
  
  RESULTS
  IORT was delivered during nephrectomy for advanced disease (28%) or during resection of locally recurrent RCC in the renal fossa (72%). Sixty-nine percent of the patients were male, and the median age was 58 years. At the time of primary resection, the T stages were as follows: 17% T1, 12% T2, 55% T3, and 16% T4. Eighty-seven percent of the patients had a visibly complete resection of tumor. Preoperative or postoperative external beam radiation therapy was administered to 27% and 35% of patients, respectively. The 5-year OS was 37% for advanced disease and 55% for locally recurrent disease. The respective 5-year DSS was 41% and 60%. The respective 5-year DFS was 39% and 52%. Initial nodal involvement (hazard ratio [HR] 2.9-3.6, P<.01), presence of sarcomatoid features (HR 3.7-6.9, P<.05), and higher IORT dose (HR 1.3, P<.001) were statistically significantly associated with decreased survival. Adjuvant systemic therapy was associated with decreased DSS (HR 2.4, P=.03). For locally recurrent tumors, positive margin status (HR 2.6, P=.01) was associated with decreased OS.
  
  
  CONCLUSIONS
  We report the largest known cohort of patients with RCC managed by IORT and have identified several factors associated with survival. The outcomes for patients receiving IORT in the setting of local recurrence compare favorably to similar cohorts treated by local resection alone suggesting the potential for improved DFS with IORT.
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Paly
authors.affiliation: Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Hallemeier
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Biggs
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Niemierko
authors.affiliation: Department of Radiation Oncology, University of Heidelberg, Heidelberg, Germany.
authors.forename: Falk
authors.initials: F
authors.lastname: Roeder
authors.affiliation: Radiation Oncology Division, University of Navarre, Pamplona, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Martínez-Monge
authors.affiliation: Department of Urology, University of California San Francisco, San Francisco, California.
authors.forename: Jared
authors.initials: J
authors.lastname: Whitson
authors.affiliation: Departamento de Oncología, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
authors.forename: Felipe A
authors.initials: FA
authors.lastname: Calvo
authors.affiliation: Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University Clinics, Salzburg, Austria.
authors.forename: Gerd
authors.initials: G
authors.lastname: Fastner
authors.affiliation: Department of Radiotherapy and Radio-Oncology, Paracelsus Medical University Clinics, Salzburg, Austria.
authors.forename: Felix
authors.initials: F
authors.lastname: Sedlmayer
authors.affiliation: Department of Radiation Oncology, Mayo Clinic, Scottsdale, Arizona.
authors.forename: William W
authors.initials: WW
authors.lastname: Wong
authors.affiliation: Department of Radiation Oncology, Seidman Cancer Center University Hospitals Case Medical Center, Cleveland, Ohio.
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: Ellis
authors.affiliation: Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Haddock
authors.affiliation: Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Richard
authors.initials: R
authors.lastname: Choo
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: William U
authors.initials: WU
authors.lastname: Shipley
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Anthony L
authors.initials: AL
authors.lastname: Zietman
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts. Electronic address: jefstathiou@partners.org.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Efstathiou
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D003131:Combined Modality Therapy / Q000379:methods / Q000401:mortality; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007680:Kidney Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D009392:Nephrectomy / Q000009:adverse effects; D011379:Prognosis; D016016:Proportional Hazards Models; D055815:Young Adult