title: Postoperative intensity modulated radiation therapy in high risk prostate cancer: a dosimetric comparison.
abstract: The aim of this study was to compare intensity-modulated radiation therapy (IMRT) with 3D conformal technique (3D-CRT), with respect to target coverage and irradiation of organs at risk for high dose postoperative radiotherapy (PORT) of the prostate fossa. 3D-CRT and IMRT treatment plans were compared with respect to dose to the rectum and bladder. The dosimetric comparison was carried out in 15 patients considering 2 different scenarios: (1) exclusive prostate fossa irradiation, and (2) pelvic node irradiation followed by a boost on the prostate fossa. In scenario (1), a 3D-CRT plan (box technique) and an IMRT plan were calculated and compared for each patient. In scenario (2), 3 treatment plans were calculated and compared for each patient: (a) 3D-CRT box technique for both pelvic (prophylactic nodal irradiation) and prostate fossa irradiation (3D-CRT only); (b) 3D-CRT box technique for pelvic irradiation followed by an IMRT boost to the prostatic fossa (hybrid 3D-CRT and IMRT); and (c) IMRT for both pelvic and prostate fossa irradiation (IMRT only). For exclusive prostate fossa irradiation, IMRT significantly reduced the dose to the rectum (lower Dmean, V50%, V75%, V90%, V100%, EUD, and NTCP) and the bladder (lower Dmean, V50%, V90%, EUD and NTCP). When prophylactic irradiation of the pelvis was also considered, plan C (IMRT only) performed better than plan B (hybrid 3D-CRT and IMRT) as respect to both rectum and bladder irradiation (reduction of Dmean, V50%, V75%, V90%, equivalent uniform dose [EUD], and normal tissue complication probability [NTCP]). Plan (b) (hybrid 3D-CRT and IMRT) performed better than plan (a) (3D-CRT only) with respect to dose to the rectum (lower Dmean, V75%, V90%, V100%, EUD, and NTCP) and the bladder (Dmean, EUD, and NTCP). Postoperative IMRT in prostate cancer significantly reduces rectum and bladder irradiation compared with 3D-CRT.
authors.affiliation: Department of Radiotherapy, John Paul II Center for High Technology Research and Education in Biomedical Sciences, Catholic University, Campobasso, Italy.
authors.forename: Cinzia
authors.initials: C
authors.lastname: Digesú
authors.forename: Savino
authors.initials: S
authors.lastname: Cilla
authors.forename: Andrea
authors.initials: A
authors.lastname: De Gaetano
authors.forename: Mariangela
authors.initials: M
authors.lastname: Massaccesi
authors.forename: Gabriella
authors.initials: G
authors.lastname: Macchia
authors.forename: Edy
authors.initials: E
authors.lastname: Ippolito
authors.forename: Francesco
authors.initials: F
authors.lastname: Deodato
authors.forename: Simona
authors.initials: S
authors.lastname: Panunzi
authors.forename: Chiara
authors.initials: C
authors.lastname: Iapalucci
authors.forename: Gian Carlo
authors.initials: GC
authors.lastname: Mattiucci
authors.forename: Elisa
authors.initials: E
authors.lastname: D'Angelo
authors.forename: Gilbert D A
authors.initials: GD
authors.lastname: Padula
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Valentini
authors.forename: Numa
authors.initials: N
authors.lastname: Cellini
authors.forename: Angelo
authors.initials: A
authors.lastname: Piermattei
authors.forename: Alessio G
authors.initials: AG
authors.lastname: Morganti
mesh_terms: D000368:Aged; D003131:Combined Modality Therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D011874:Radiometry; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated