title: High- and low-dose-rate intraoperative radiotherapy for thoracic malignancies resected with close or positive margins.
abstract: OBJECTIVE
  Local recurrence is a significant problem after surgical resection of thoracic tumors. As intraoperative radiotherapy (IORT) can deliver radiation directly to the threatened margin, we have used this therapy in an attempt to reduce local recurrence, using high-dose-rate (HDR) as well as low-dose-rate (LDR) techniques.
  
  
  METHODS
  We performed a retrospective review of patients undergoing LDR ((125)I) mesh placement or HDR ((192)Ir) afterloading therapy during lung tumor resection between 2001 and 2013 at our institution. Competing risks methods were used to estimate the cumulative incidence of local failure. We also assessed possible predictive factors of local failure.
  
  
  RESULTS
  Fifty-nine procedures (41 LDR and 18 HDR) were performed on 58 patients. Median follow-up was 55.1 months. Cumulative incidence of local failure at 1, 2, and 3 years was 28.5%, 34.2%, and 34.2%, respectively. Median overall survival was 39.9 months. There was no significant difference in local failure according to margin status, HDR vs. LDR, use of adjuvant external beam radiotherapy, or metastatic vs. primary tumor. Two patients (3.4%) experienced Grade 3+ toxicities likely related to brachytherapy. Additionally, 7 patients experienced Grade 3+ postsurgical complications unlikely related to brachytherapy.
  
  
  CONCLUSIONS
  IORT is associated with good local control after resection of thoracic tumors otherwise at very high risk for local recurrence. There is a low incidence of severe toxicity attributable to brachytherapy. HDR-IORT appears to have equivalent outcomes to LDR-IORT. HDR or LDR-IORT can, therefore, be considered in situations where the oncologic completeness of thoracic tumor resection is in doubt.
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Christopher
authors.initials: C
authors.lastname: Fleming
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Andreas
authors.initials: A
authors.lastname: Rimner
authors.affiliation: Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Gil'ad N
authors.initials: GN
authors.lastname: Cohen
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Kaitlin M
authors.initials: KM
authors.lastname: Woo
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology, Mount Sinai Medical Center, New York, NY.
authors.forename: Kenneth E
authors.initials: KE
authors.lastname: Rosenzweig
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Kaled M
authors.initials: KM
authors.lastname: Alektiar
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Zelefsky
authors.affiliation: Thoracic Surgery Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Manjit S
authors.initials: MS
authors.lastname: Bains
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY. Electronic address: wua@mskcc.org.
authors.forename: Abraham J
authors.initials: AJ
authors.lastname: Wu
mesh_terms: D000328:Adult; D000368:Aged; D001918:Brachytherapy / Q000009:adverse effects; D006801:Humans; D007430:Intraoperative Care; D008175:Lung Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control*; D018365:Neoplasm, Residual; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D015996:Survival Rate; D055815:Young Adult
keywords: High-dose rate; Intraoperative radiotherapy; Thorax
references.citation: J Clin Oncol. 2007 Mar 10;25(8):971-7
references.pmid: 17350946
references.citation: Clin Infect Dis. 1996 Mar;22(3):424-9
references.pmid: 8852957
references.citation: Am J Surg. 1993 May;165(5):572-6
references.pmid: 8488939
references.citation: Int J Radiat Oncol Biol Phys. 2010 Mar 15;76(4):1114-20
references.pmid: 19540065
references.citation: J Clin Oncol. 2014 Aug 10;32(23):2456-62
references.pmid: 24982457
references.citation: Brachytherapy. 2009 Jan-Mar;8(1):63-9
references.pmid: 19056322
references.citation: J Thorac Cardiovasc Surg. 2011 Nov;142(5):1143-51
references.pmid: 21872277
references.citation: PLoS One. 2014;9(2):e90014
references.pmid: 24587187