title: The use of an interstitial boost in the conservative treatment of breast cancer: how to perform it routinely in a radiotherapy department.
abstract: OBJECTIVE
  To demonstrate the utility of a boost with interstitial brachytherapy (BT) in breast-conserving therapy (BCT) by doing a thorough review of the literature and describing in detail our technique for delivering this boost.
  
  
  METHODS
  Our department has been delivering the boost with interstitial BT since 1989, in most cases with rigid needles and a theoretical dosimetry. In the early years, we used low-dose-rate (LDR) with iridium-192 wires. The dose administered was 15 Gy if there were no risk factors for local relapse or 20-25 Gy in the presence of risk factors. The risk factors considered were the presence of a close margin (less than 10 mm) and an extensive intraductal component (more than 25%). After 2002, we switched to high-dose-rate (HDR); using the linear quadratic model we changed the low dose to 3 fractions of 4.5 Gy in the case of no risk factors for local relapse or to 3 fractions of 5 Gy in the presence of risk factors.
  
  
  RESULTS
  In 79 consecutive boost patients treated in our department between 2010 and 2011, with a median follow-up of 46 months, the local control rate was 97.47%. With respect to cosmesis, fibrosis occurred in 17 cases (21.5%) and hyperpigmentation in 26 cases (32.9%). Our hospital's results are comparable in terms of local control and cosmesis to those of other authors.
  
  
  CONCLUSIONS
  This educational article describes our department's boost technique with rigid needles and comments briefly on our results using this technique in a group of consecutively treated patients in our department. A review of the literature and the published results on local control and cosmesis is also described.
authors.affiliation: Radiation Oncology Department, Institut Català d'Oncologia, Barcelona, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Gutiérrez
authors.affiliation: Radiation Oncology Department, Institut Català d'Oncologia, Barcelona, Spain.
authors.forename: Dina
authors.initials: D
authors.lastname: Najjari
authors.affiliation: Radiation Oncology Department, Institut Català d'Oncologia, Barcelona, Spain.
authors.forename: Evelyn
authors.initials: E
authors.lastname: Martínez
authors.affiliation: Radiation Oncology Department, Institut Català d'Oncologia, Barcelona, Spain.
authors.forename: Saray
authors.initials: S
authors.lastname: Botella
authors.affiliation: Radiation Oncology Department, Institut Català d'Oncologia, Barcelona, Spain.
authors.forename: Arantxa
authors.initials: A
authors.lastname: Eraso
authors.affiliation: Radiation Oncology Department, Institut Català d'Oncologia, Barcelona, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Pino
authors.affiliation: Radiation Oncology Department, Institut Català d'Oncologia, Barcelona, Spain.
authors.forename: Ferran
authors.initials: F
authors.lastname: Moreno
authors.affiliation: Radiation Oncology Department, Institut Català d'Oncologia, Barcelona, Spain.
authors.forename: Joan
authors.initials: J
authors.lastname: Pera
authors.affiliation: Radiation Oncology Department, Institut Català d'Oncologia, Barcelona, Spain.
authors.forename: Ferran
authors.initials: F
authors.lastname: Guedea
keywords: brachytherapy; breast cancer; breast conserving therapy; interstitial boost
references.citation: Int J Radiat Oncol Biol Phys. 2007 Aug 1;68(5):1381-7
references.pmid: 17418974
references.citation: Radiother Oncol. 2003 May;67(2):159-64
references.pmid: 12812845
references.citation: Int J Radiat Oncol Biol Phys. 2011 Mar 15;79(4):1048-54
references.pmid: 20510548
references.citation: Radiother Oncol. 2004 Jul;72(1):25-33
references.pmid: 15236871
references.citation: Cancer Radiother. 2003 Apr;7(2):107-20
references.pmid: 12719040
references.citation: Clin Oncol (R Coll Radiol). 2007 Oct;19(8):596-603
references.pmid: 17706403
references.citation: Int J Radiat Oncol Biol Phys. 2000 Oct 1;48(3):757-65
references.pmid: 11020573
references.citation: Am J Clin Oncol. 2001 Feb;24(1):26-32
references.pmid: 11232945
references.citation: Radiother Oncol. 2002 Apr;63(1):47-58
references.pmid: 12065103
references.citation: Radiother Oncol. 1995 Feb;34(2):105-13
references.pmid: 7597208
references.citation: Radiother Oncol. 1987 Jan;8(1):1-9
references.pmid: 3809596
references.citation: Int J Radiat Oncol Biol Phys. 1996 Mar 15;34(5):995-1007
references.pmid: 8600112
references.citation: Int J Radiat Oncol Biol Phys. 1991 Oct;21(5):1173-7
references.pmid: 1938515
references.citation: Clin Oncol (R Coll Radiol). 2003 May;15(3):156-9
references.pmid: 12801055
references.citation: Int J Radiat Oncol Biol Phys. 1995 Feb 15;31(4):753-64
references.pmid: 7860386
references.citation: Int J Radiat Oncol Biol Phys. 1997 Sep 1;39(2):381-93
references.pmid: 9308942
references.citation: Cancer Radiother. 2004 Aug;8(4):248-54
references.pmid: 15450518
references.citation: Int J Radiat Oncol Biol Phys. 1997 Mar 1;37(4):845-52
references.pmid: 9128961
references.citation: Radiother Oncol. 1995 Feb;34(2):114-20
references.pmid: 7597209
references.citation: Strahlenther Onkol. 2002 Nov;178(11):615-23
references.pmid: 12426672
references.citation: Pathol Oncol Res. 2001;7(4):241-50
references.pmid: 11882903
references.citation: J Clin Oncol. 2007 Aug 1;25(22):3259-65
references.pmid: 17577015
references.citation: Strahlenther Onkol. 2002 Nov;178(11):607-14
references.pmid: 12426671
references.citation: Rep Pract Oncol Radiother. 2010 Feb 18;15(1):1-7
references.pmid: 24376915
references.citation: Strahlenther Onkol. 1999 Oct;175(10):478-83
references.pmid: 10554641