Paolo Bagalà1, Gianluca Ingrosso1, Maria Daniela Falco1, Sara Petrichella2, Marco D'Andrea3, Maria Rago1, Andrea Lancia1, Claudia Bruni1, Elisabetta Ponti1, Riccardo Santoni1. 1. Department of Diagnostic Imaging, Molecular Imaging, Interventional Radiology and Radiotherapy, University of Rome Tor Vergata, Viale Oxford 81, 00133 Rome, Italy. 2. Computer Science and Bioinformatics Laboratory, Integrated Research Centre, Campus Bio-Medico University, Via Alvaro del Portillo 21, 00128, Rome, Italy. 3. Laboratory of Medical Physics and Expert Systems, National Cancer Institute Regina Elena, V. E. Chianesi 53, 00144 Rome, Italy.
Abstract
PURPOSE: In prostate cancer radiotherapy, the relationship between genitourinary (GU) toxicity and clinical-dosimetric parameters is debated. We report our analysis of the parameters associated with GU toxicity. MATERIALS AND METHODS: Eighty-six consecutive patients treated with conformal radiotherapy for localized prostate cancer were retrospectively analyzed; the bladder was delineated both as "whole bladder" (WB: Defined in its entirety as a solid organ) and "inferior bladder" (IB: Corresponding to the distal part of the bladder). GU toxicity and dose-volume parameters were correlated using the point biserial correlation coefficient. The normal tissue complication probability (NTCP) cut-off volume model was fitted to toxicity data; univariate analysis between GU toxicity and clinical parameters was done. RESULTS: Acute GU toxicity was correlated to doses higher than 80 Gy (P < 0.05) while late GU was correlated to doses higher than 77 Gy for WB and from 77.5 Gy for IB. The NTCP cut-off volume model identified for both WB and IB a bladder volume of 6 cc receiving a dose ≥77 Gy corresponding to a 50% probability of GU toxicity. At univariate analysis, acute GU toxicity was correlated with smoke (P < 0.001). CONCLUSION: Bladder maximal doses quantified as hotspots show a correlation to GU toxicity.
PURPOSE: In prostate cancer radiotherapy, the relationship between genitourinary (GU) toxicity and clinical-dosimetric parameters is debated. We report our analysis of the parameters associated with GU toxicity. MATERIALS AND METHODS: Eighty-six consecutive patients treated with conformal radiotherapy for localized prostate cancer were retrospectively analyzed; the bladder was delineated both as "whole bladder" (WB: Defined in its entirety as a solid organ) and "inferior bladder" (IB: Corresponding to the distal part of the bladder). GU toxicity and dose-volume parameters were correlated using the point biserial correlation coefficient. The normal tissue complication probability (NTCP) cut-off volume model was fitted to toxicity data; univariate analysis between GU toxicity and clinical parameters was done. RESULTS: Acute GU toxicity was correlated to doses higher than 80 Gy (P < 0.05) while late GU was correlated to doses higher than 77 Gy for WB and from 77.5 Gy for IB. The NTCP cut-off volume model identified for both WB and IB a bladder volume of 6 cc receiving a dose ≥77 Gy corresponding to a 50% probability of GU toxicity. At univariate analysis, acute GU toxicity was correlated with smoke (P < 0.001). CONCLUSION: Bladder maximal doses quantified as hotspots show a correlation to GU toxicity.
Authors: Isabelle R Miousse; Laura E Ewing; Charles M Skinner; Rupak Pathak; Sarita Garg; Kristy R Kutanzi; Stepan Melnyk; Martin Hauer-Jensen; Igor Koturbash Journal: Am J Physiol Gastrointest Liver Physiol Date: 2020-01-21 Impact factor: 4.052