title: [Prostate cancer boost using high-dose-rate brachytherapy: impact of the learning curve on the dosimetry].
abstract: OBJECTIVE
  To analyse the influence of the learning curve on dosimetric data for high-dose-rate brachytherapy prostate cancer boost.
  
  
  METHODS
  From February 2009 to May 2012, after a first course of external beam radiation therapy (46Gy/23 fractions), 124 patients underwent high-dose-rate brachytherapy boost using Plato™ (Nucletron, an Elekta company, Elekta AB, Stockholm, Sweden). The impact of the learning curve on the dosimetric quality of the prostate implant was assessed. The dosimetric data have been analysed: clinical target volume (CTV), D90 (dose to 90 % of CTV), D100, V100 (part on the CTV receiving 100 % of the dose), V150, V200 and DHI (dose non-homogeneity index). The doses delivered to 0.1, 1 and 2 cm(3) of the rectum and urethra were calculated.
  
  
  RESULTS
  During the study period (39 months), a significant reduction of V150 (P<0.001), V200 (P<0.001), D0.1rectum (P<0.001), D1rectum (P<0.001), D2rectum (P<0.001), D0.1urethra (P<0.001), and D1urethra (P<0.002) was observed associated with a significant degradation of the D90 (P<0.001) but not significant for the V100 (P=0.29) and the D100 (P=0.3).
  
  
  CONCLUSIONS
  This study confirms that the dosimetric quality of high-dose-rate brachytherapy prostate implant is significantly improved during the learning curve period.
authors.affiliation: Département de radiothérapie, centre Antoine-Lacassagne, université Nice-Sophia, 33, avenue de Valombrose, 06000 Nice, France; Département de radiothérapie, centre Jean-Perrin, université d'Auvergne, 58, rue Montalembert, 63000 Clermont-Ferrand, France.
authors.forename: C
authors.initials: C
authors.lastname: Benhaïm
authors.affiliation: Département de radiothérapie, centre Antoine-Lacassagne, université Nice-Sophia, 33, avenue de Valombrose, 06000 Nice, France.
authors.forename: M-È
authors.initials: MÈ
authors.lastname: Chand
authors.affiliation: Département de radiothérapie, centre Antoine-Lacassagne, université Nice-Sophia, 33, avenue de Valombrose, 06000 Nice, France; Unité de biostatistique, centre Antoine-Lacassagne, université Nice-Sophia, 33, avenue de Valombrose, 06000 Nice, France.
authors.forename: J
authors.initials: J
authors.lastname: Gal
authors.affiliation: Département de radiothérapie, centre Antoine-Lacassagne, université Nice-Sophia, 33, avenue de Valombrose, 06000 Nice, France.
authors.forename: H
authors.initials: H
authors.lastname: Hijazi
authors.affiliation: Département de radiothérapie, centre Antoine-Lacassagne, université Nice-Sophia, 33, avenue de Valombrose, 06000 Nice, France.
authors.forename: M
authors.initials: M
authors.lastname: Gautier
authors.affiliation: Département de radiothérapie, centre Antoine-Lacassagne, université Nice-Sophia, 33, avenue de Valombrose, 06000 Nice, France. Electronic address: jean-michel.hannoun-levi@nice.unicancer.fr.
authors.forename: J-M
authors.initials: JM
authors.lastname: Hannoun-Lévi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy; D019583:Dose Fractionation, Radiation; D006801:Humans; D059032:Learning Curve; D008297:Male; D008875:Middle Aged; D058958:Organs at Risk; D011471:Prostatic Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted
keywords: Brachytherapy; Courbe d’apprentissage; Curiethérapie; Dosimetry; Dosimétrie; Learning curve; Prostate cancer