title: IMRT significantly reduces acute toxicity of whole-pelvis irradiation in patients treated with post-operative adjuvant or salvage radiotherapy after radical prostatectomy.
abstract: OBJECTIVE
  To investigate the role of IMRT in reducing the risk of acute genito-urinary (GU), upper gastrointestinal (uGI) and lower gastrointestinal (lGI) toxicity following whole-pelvis irradiation (WPRT) after radical prostatectomy.
  
  
  METHODS
  172 consecutive patients with prostate cancer were post-operatively irradiated to the prostatic bed (PB) and pelvic lymph-nodal area with adjuvant (n=100) or salvage (n=72) intent. Eighty-one patients underwent three-dimensional conformal (3DCRT) WPRT, while the remaining 91 underwent IMRT (54/91 with helical tomotherapy (HTT); 37/91 with Linac intensity-modulated RT (LinacIMRT)).
  
  
  RESULTS
  Patients treated with IMRT experienced a decreased risk of acute toxicity. The crude incidence of grade > or =2 toxicity was GU 12.3% vs. 6.6% (p=0.19); lGI 8.6% vs. 3.2% (p=0.14); uGI 22.2% vs. 6.6% (p=0.004), for 3DCRT and IMRT, respectively. With respect to uGI and lGI, the acute toxicity profile of the HTT patients was even better when compared to that of 3DCRT patients (crude incidence:1.8% and 0.0%, respectively). Treatment interruptions due to uGI toxicity were 11/81 in the 3DCRT group vs. 2/91 in the IMRT group (p=0.006).
  
  
  CONCLUSIONS
  The risk of acute toxicity following post-operative WPRT delivered by means of IMRT was reduced compared to that of 3DCRT. The most significant reduction concerned uGI, mainly owing to better bowel sparing with IMRT.
authors.affiliation: Department of Radiotherapy, Scientific Institute H San Raffaele, Milan, Italy. filippo.alongi@hsr.it
authors.forename: Filippo
authors.initials: F
authors.lastname: Alongi
authors.forename: Claudio
authors.initials: C
authors.lastname: Fiorino
authors.forename: Cesare
authors.initials: C
authors.lastname: Cozzarini
authors.forename: Sara
authors.initials: S
authors.lastname: Broggi
authors.forename: Lucia
authors.initials: L
authors.lastname: Perna
authors.forename: Giovanni Mauro
authors.initials: GM
authors.lastname: Cattaneo
authors.forename: Riccardo
authors.initials: R
authors.lastname: Calandrino
authors.forename: Nadia
authors.initials: N
authors.lastname: Di Muzio
mesh_terms: D000368:Aged; D041981:Gastrointestinal Tract / Q000528:radiation effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000528:radiation effects*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated; D012189:Retrospective Studies; D016879:Salvage Therapy; D014566:Urogenital System / Q000528:radiation effects