title: Physical and clinical implications of radiotherapy treatment of prostate cancer using a full bladder protocol.
abstract: OBJECTIVE
  To assess the dosimetric and clinical implication when applying the full bladder protocol for the treatment of the localized prostate cancer (PCA).
  
  
  METHODS
  A total of 26 consecutive patients were selected for the present study. Patients underwent two series of CT scans: the day of the simulation and after 40 Gy. Each series consisted of two consecutive scans: (1) full bladder (FB) and (2) empty bladder (EB). The contouring of clinical target volumes (CTVs) and organs at risk (OAR) were compared to evaluate organ motion. Treatment plans were compared by dose distribution and dose-volume histograms (DVH).
  
  
  RESULTS
  CTV shifts were negligible in the laterolateral and superior-inferior directions (the maximum shift was 1.85 mm). Larger shifts were recorded in the anterior-posterior direction (95% CI, 0.83-4.41 mm). From the dosimetric point of view, shifts are negligible: the minimum dose to the CTV was 98.5% (median; 95%CI, 95-99%). The potential advantage for GU toxicity in applying the FB treatment protocol was measured: the ratio between full and empty bladder dose-volume points (selected from our protocol) is below 0.61, excluding the higher dose region where DVHs converge.
  
  
  CONCLUSIONS
  Having a FB during radiotherapy does not affect treatment effectiveness, on the contrary it helps achieve a more favorable DVH and lower GU toxicities.
authors: Department of Medical Physics, Istituto Europeo di Oncologia, Milan, Italy. raffaella.cambria@ieo.it
authors: Raffaella
authors: R
authors: Cambria
authors: Barbara A
authors: BA
authors: Jereczek-Fossa
authors: Dario
authors: D
authors: Zerini
authors: Federica
authors: F
authors: Cattani
authors: Flavia
authors: F
authors: Serafini
authors: Rosa
authors: R
authors: Luraschi
authors: Guido
authors: G
authors: Pedroli
authors: Roberto
authors: R
authors: Orecchia
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008297:Male; D008875:Middle Aged; D058958:Organs at Risk; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D011835:Radiation Protection / Q000379:methods*; D011874:Radiometry / Q000379:methods; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed; D001743:Urinary Bladder / Q000528:radiation effects*