Feliciano García-Vicente PhD, Presenter: Nothing to Disclose

Almudena Zapatero MD, Abstract Co-Author: Nothing to Disclose

David Sevillano MS, Abstract Co-Author: Nothing to Disclose

Carlos Ferrer MS, Abstract Co-Author: Nothing to Disclose

Carmen Martín-DeVidales MD, PhD, Abstract Co-Author: Nothing to Disclose

To identify dose volume parameters and clinical factors predictive of a higher risk of grade ≥2 late urinary morbidity in patients with prostate cancer treated with three-dimensional conformal radiotherapy (3D-CRT) in a prospective dose escalation study.

A total of 213 evaluable patients with T1c-T3 prostate cancer treated with 3D-CRT to a dose of > 72.00 Gy and a minimum follow-up of one year were retrospectively analyzed. The mean ICRU reference dose was of 77.38 Gy, range 72.03 to 84.14 Gy. Urinary morbidity was grading according to the RTOG late radiation morbidity scoring scale. Clinical and dosimetric variables were investigated to determine their correlation with grade ≥2 late urinary toxicity. A secondary study was made to investigate the same correlations with grade ≥2 hematuria.

25 of the 213 patients (12%) experienced grade ≥2 late urinary toxicity and only 2 patients (1%) had grade 3 complications (ICRU radiation doses 73.3 Gy and 78.5 Gy). No patients developed grade 4 or 5 late toxicities. Of the 25 patients with grade ≥2 urinary toxicity, hematuria was the main symptom in 21 (10%) with only 2 patients (1%) experiencing grade 3 hematuria. On univariate analysis, all the dosimetric parameters failed to show a significant correlation with bladder toxicity. Only the history of TUR (p=0.008) was significantly correlated with grade ≥2 urinary morbidity. TUR performed prior to RT was also the only significant factor associated with a higher risk of hematuria (p=0.002).

Tolerance of bladder at the prostate radiation dose level of 72 - 84 Gy with 3D-CRT remains acceptable with no grade 4-5 late complications. The present study indicates the absence of dose and dose-volume effect on the risk of GU toxicity at this dose level and suggests that minor surgical manipulations (as TUR of the bladder) are relevant factors contributing to late bladder toxicity.

High-dose conformal radiotherapy for prostate cancer is safe and associated with low-acceptable risk of late urinary complications

García-Vicente, F, Zapatero, A, Sevillano, D, Ferrer, C, Martín-DeVidales, C, Late Genito-Urinary Morbidity after 3D Conformal Radiotherapy for Prostate Cancer: Absence of Dose and Dose-Volume Effect?.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5006670.html