title: Image-guided high-dose-rate brachytherapy boost to the dominant intraprostatic lesion using multiparametric magnetic resonance imaging including spectroscopy: Results of a prospective study.
abstract: To evaluate the long-term outcomes of image-guided high-dose-rate (HDR) brachytherapy boost to the dominant intraprostatic lesion (DIL) using multiparametric magnetic resonance imaging (MRI), including spectroscopy (MRI/magnetic resonance spectroscopy [MRS]).
  
  
  
  Between December 2009 and March 2011, 20 patients with intermediate-risk prostate cancer underwent multiparametric MRI/MRS protocol before treatment. All patients were treated with an external beam radiotherapy dose of 40 Gy, combined with an HDR brachytherapy boost of 15 Gy. Concurrently, the DIL received a boost of 18 Gy. Missing data during followup were handled with multiple imputations.
  
  
  
  The median followup was 62 months (range, 23-71 months). Six patients (31%) were classified as favorable intermediate risk and 13 patients (69%) as unfavorable intermediate risk. One patient experienced a prostate-specific antigen biochemical failure, and the 5-year biochemical failure-free survival rate was of 94.7%. The mean International Prostate Symptom Score rose from 7, with respect to baseline, to 10.42 1 month after treatment, and rapidly decreased to 6.97 after 3 months. Grade 1, 2, and 3 acute genitourinary toxicities were reported in 13 (68%), 3 (16%), and 1 (5%) patients, respectively. Grade 1 and 2 late genitourinary toxicities were reported in 9 (53%) and 3 (18%) patients, respectively. Only grade 1 acute and late gastrointestinal toxicities were reported in 4 (21%) and 3 (18%) patients, respectively.
  
  
  
  Delivering an HDR brachytherapy boost to the DIL using image-guided multiparametric MRI/MRS is feasible with good outcomes for biochemical control, acute and late toxicities, and dosimetric constraints for critical organs.
authors.affiliation: Département de radio-oncologie, CHU de Québec-Université Laval, Québec, Québec, Canada; Centre de recherche du CHU de Québec, Québec, Québec, Canada; Centre de recherche sur le cancer de l'Université Laval, Québec, Québec, Canada. Electronic address: eric.vigneault@mail.chudequebec.ca.
authors.forename: Eric
authors.initials: E
authors.lastname: Vigneault
authors.affiliation: Département de radio-oncologie, CHU de Québec-Université Laval, Québec, Québec, Canada; Centre de recherche du CHU de Québec, Québec, Québec, Canada.
authors.forename: Khaly
authors.initials: K
authors.lastname: Mbodji
authors.affiliation: Département de d'imagerie médicale, CHU de Québec-Université Laval, Québec, Québec, Canada.
authors.forename: Louis-Gabriel
authors.initials: LG
authors.lastname: Racine
authors.affiliation: Département de d'imagerie médicale, CHU de Québec-Université Laval, Québec, Québec, Canada.
authors.forename: Eric
authors.initials: E
authors.lastname: Chevrette
authors.affiliation: Département de radio-oncologie, CHU de Québec-Université Laval, Québec, Québec, Canada.
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Lavallée
authors.affiliation: Département de radio-oncologie, CHU de Québec-Université Laval, Québec, Québec, Canada; Centre de recherche du CHU de Québec, Québec, Québec, Canada; Centre de recherche sur le cancer de l'Université Laval, Québec, Québec, Canada.
authors.forename: André-Guy
authors.initials: AG
authors.lastname: Martin
authors.affiliation: Département de radio-oncologie, CHU de Québec-Université Laval, Québec, Québec, Canada; Centre de recherche du CHU de Québec, Québec, Québec, Canada; Centre de recherche sur le cancer de l'Université Laval, Québec, Québec, Canada; Département de physique, de génie physique et d'optique, Université Laval, Québec, Québec, Canada.
authors.forename: Philippe
authors.initials: P
authors.lastname: Després
authors.affiliation: Département de radio-oncologie, CHU de Québec-Université Laval, Québec, Québec, Canada; Centre de recherche du CHU de Québec, Québec, Québec, Canada; Centre de recherche sur le cancer de l'Université Laval, Québec, Québec, Canada; Département de physique, de génie physique et d'optique, Université Laval, Québec, Québec, Canada.
authors.forename: Luc
authors.initials: L
authors.lastname: Beaulieu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D053783:Magnetic Resonance Imaging, Interventional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000032:analysis; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D011829:Radiation Dosage; D061089:Radiotherapy, Image-Guided / Q000379:methods*; D013057:Spectrum Analysis; D016019:Survival Analysis; D014566:Urogenital System / Q000528:radiation effects
chemical_list: D017430:Prostate-Specific Antigen
keywords: Dominant intraprostatic lesion; HDR brachytherapy; MRI; Prostate cancer; Spectroscopy