- Email: [email protected]
Prediction of Extraprostatic Extension in Intermediate Risk Prostate Cancer: The Evolving Role of Endorectal MRI
I. J. Radiation Oncology d Biology d Physics
S398
Volume 81, Number 2, Supplement, 2011
however, DM patients were more likely to receive IMRT (p\0.01), ADT (p = 0.05), and have shorter follow-up (median 44 vs. 58 mo, p\0.01). Univariate analyses demonstrated that higher RT dose, lack of IMRT, and DM were associated with worse grade 2+ GU toxicity, while TURP and DM were associated with late grade 3+ GU toxicity. Meanwhile, no ADT use, age $70, and anticoagulation (AC) were associated with worse grade 2+ GI toxicity, and age $70 and AC were associated with late grade 3+ GI toxicity. Within the subset of DM patients (n = 103), there was no difference in any GU or GI toxicity for patients on insulin vs. on oral meds (all p.0.10). Results of the multivariable analyses for late toxicity are shown below. Patients with DM did have a higher risk of late grade 2+ (RR 1.36, p = 0.10) and 3+ GU toxicity (RR 2.74, p = 0.04). Conclusions: A higher incidence of late GU toxicity was seen in DM patients treated for prostate cancer. This relationship may be useful to consider when conducting treatment planning for diabetic patients, especially those receiving dose-escalated RT or with history of TURP. Further study is necessary to determine whether glycemic control can influence the evolution of late toxicity. Results of Multivariable Analysis.
Late Grade 2+ GU toxicity RT dose $74 Diabetes IMRT Late Grade 3+ GU toxicity TURP Diabetes Late Grade 2 + GI toxicity Age $ 70 Anticoagulation No ADT Diabetes Late Grade 3+ GI toxicity Age $ 70 Anticoagulation Diabetes
RR (95% CI)
P value
1.87 (1.05 - 3.28) 1.36 (0.95 - 1.90) 1.00 (0.56 - 1.75)
0.03 0.10 0.98
3.01 (0.99 - 7.62) 2.74 (1.05 - 6.43)
0.06 0.04
1.73 (1.15 - 2.65) 2.86 (1.61 - 4.77) 1.57 (1.04 - 2.41) 1.00 (0.54 - 1.73)
0.01 \0.01 0.03 0.98
2.19 (1.06 - 4.85) 3.02 (1.12 - 6.88) 1.18 (0.40 - 2.86)
0.03 0.03 0.74
Author Disclosure: K. Kalakota: None. D. Correa: None. S. Liauw: None.
2393
Prediction of Extraprostatic Extension in Intermediate Risk Prostate Cancer: The Evolving Role of Endorectal MRI
T. J. Pugh, S. J. Frank, M. Achim, D. A. Kuban, A. K. Lee, S. Choi, Q. Nguyen, K. Hoffman, S. E. McGuire, D. A. Swanson University of Texas MD Anderson Cancer Center, Houston, TX Purpose/Objective(s): To determine the ability of MRI and other pre-therapy factors to predict extra-prostatic extension (EPE) and quantify the extent of EPE in men with localized, intermediate risk prostate cancer. Materials/Methods: Eight-hundred fifty-three consecutive patients treated with robot-assisted radical prostatectomy were analyzed from an IRB approved dataset. Patients with clinical stage T1-T2, Gleason score (GS) = 7 (3+4 or 4+3), and PSA \ 10 ng/ ml were extracted. Patients who underwent pre-treatment T1 (axial) and T2 (axial, coronal and sagittal) diffusion-weighted MRI with endorectal coil (ER-MRI) were eligible for further analysis. Histologic findings including quantification of EPE were compared with the following pre-treatment factors: ER-MRI, PSA, GS, clinical T-stage, and % positive core biopsies using logistic regression analysis. Results: Four-Hundred Thirty-Two patients met criteria based upon presenting disease features. Of those eligible for inclusion, 171 underwent pre-treatment ER-MRI. Pre-treatment characteristics were as follows: median age = 60 years (42-76); median PSA 4.9 (0.4-9.9); Gleason score 3+4 = 64%; T1c = 51%; T2a = 25%; T2b = 21%; T2c = 3%; .50% positive cores = 46%; EPE+ ER-MRI = 28%. Thirty-three percent (59/171) had pathologic EPE. Increasing clinical T-stage (p \ 0.0001), EPE+ ER-MRI (p = 0.005), and .50% positive biopsies (p = 0.015) were significant predictors of EPE while Gleason Score (4+3 vs. 3+4) (p = 0.08) and pre-biopsy PSA (p = 0.15) did not reach statistical significance. The median linear distance of EPE was 1.75 mm (Range \1mm-18 mm) The rates of EPE $ 5 mm and EPE $ 3mm were 5.2% and 9.9% respectively. All patients with clinical T1c disease and negative ER-MRI had either organ confined disease 97.2% (69/71) or EPE within 2 mm of the prostatic capsule 2.8% (2/71). Conclusions: In this group of selected men with localized, intermediate-risk prostate cancer, the risk of EPE was associated with clinical T-stage, percent positive core-biopsies, and findings on ER-MRI. Men with the following pre-treatment features: clinical T1c, Gleason 7, PSA \ 10 and negative ER-MRI are likely to have capsule confined disease and no EPE beyond 2 mm was identified in this favorable group. These factors can aid in the appropriate selection of men with intermediate-risk disease for brachytherapy and in designing radiation treatment target volumes. Author Disclosure: T.J. Pugh: None. S.J. Frank: None. M. Achim: None. D.A. Kuban: F. Consultant/Advisory Board; BiotheranosticsFerring Pharmaceutical. A.K. Lee: None. S. Choi: None. Q. Nguyen: None. K. Hoffman: None. S.E. McGuire: None. D.A. Swanson: None.
2394
Application of a Spacer between Prostate and Anterior Rectal Wall to Optimize Radiotherapy of Localized Prostate Cancer: Comparison of Three-dimensional Conformal (3D RT) and Intensity Modulated (IMRT) Treatment Planning Techniques
M. Pinkawa, N. Escobar Corral, M. Caffaro, M. D. Piroth, R. Holy, G. Otto, M. J. Eble RWTH Aachen University, Aachen 52074, Germany
S398
Volume 81, Number 2, Supplement, 2011
however, DM patients were more likely to receive IMRT (p\0.01), ADT (p = 0.05), and have shorter follow-up (median 44 vs. 58 mo, p\0.01). Univariate analyses demonstrated that higher RT dose, lack of IMRT, and DM were associated with worse grade 2+ GU toxicity, while TURP and DM were associated with late grade 3+ GU toxicity. Meanwhile, no ADT use, age $70, and anticoagulation (AC) were associated with worse grade 2+ GI toxicity, and age $70 and AC were associated with late grade 3+ GI toxicity. Within the subset of DM patients (n = 103), there was no difference in any GU or GI toxicity for patients on insulin vs. on oral meds (all p.0.10). Results of the multivariable analyses for late toxicity are shown below. Patients with DM did have a higher risk of late grade 2+ (RR 1.36, p = 0.10) and 3+ GU toxicity (RR 2.74, p = 0.04). Conclusions: A higher incidence of late GU toxicity was seen in DM patients treated for prostate cancer. This relationship may be useful to consider when conducting treatment planning for diabetic patients, especially those receiving dose-escalated RT or with history of TURP. Further study is necessary to determine whether glycemic control can influence the evolution of late toxicity. Results of Multivariable Analysis.
Late Grade 2+ GU toxicity RT dose $74 Diabetes IMRT Late Grade 3+ GU toxicity TURP Diabetes Late Grade 2 + GI toxicity Age $ 70 Anticoagulation No ADT Diabetes Late Grade 3+ GI toxicity Age $ 70 Anticoagulation Diabetes
RR (95% CI)
P value
1.87 (1.05 - 3.28) 1.36 (0.95 - 1.90) 1.00 (0.56 - 1.75)
0.03 0.10 0.98
3.01 (0.99 - 7.62) 2.74 (1.05 - 6.43)
0.06 0.04
1.73 (1.15 - 2.65) 2.86 (1.61 - 4.77) 1.57 (1.04 - 2.41) 1.00 (0.54 - 1.73)
0.01 \0.01 0.03 0.98
2.19 (1.06 - 4.85) 3.02 (1.12 - 6.88) 1.18 (0.40 - 2.86)
0.03 0.03 0.74
Author Disclosure: K. Kalakota: None. D. Correa: None. S. Liauw: None.
2393
Prediction of Extraprostatic Extension in Intermediate Risk Prostate Cancer: The Evolving Role of Endorectal MRI
T. J. Pugh, S. J. Frank, M. Achim, D. A. Kuban, A. K. Lee, S. Choi, Q. Nguyen, K. Hoffman, S. E. McGuire, D. A. Swanson University of Texas MD Anderson Cancer Center, Houston, TX Purpose/Objective(s): To determine the ability of MRI and other pre-therapy factors to predict extra-prostatic extension (EPE) and quantify the extent of EPE in men with localized, intermediate risk prostate cancer. Materials/Methods: Eight-hundred fifty-three consecutive patients treated with robot-assisted radical prostatectomy were analyzed from an IRB approved dataset. Patients with clinical stage T1-T2, Gleason score (GS) = 7 (3+4 or 4+3), and PSA \ 10 ng/ ml were extracted. Patients who underwent pre-treatment T1 (axial) and T2 (axial, coronal and sagittal) diffusion-weighted MRI with endorectal coil (ER-MRI) were eligible for further analysis. Histologic findings including quantification of EPE were compared with the following pre-treatment factors: ER-MRI, PSA, GS, clinical T-stage, and % positive core biopsies using logistic regression analysis. Results: Four-Hundred Thirty-Two patients met criteria based upon presenting disease features. Of those eligible for inclusion, 171 underwent pre-treatment ER-MRI. Pre-treatment characteristics were as follows: median age = 60 years (42-76); median PSA 4.9 (0.4-9.9); Gleason score 3+4 = 64%; T1c = 51%; T2a = 25%; T2b = 21%; T2c = 3%; .50% positive cores = 46%; EPE+ ER-MRI = 28%. Thirty-three percent (59/171) had pathologic EPE. Increasing clinical T-stage (p \ 0.0001), EPE+ ER-MRI (p = 0.005), and .50% positive biopsies (p = 0.015) were significant predictors of EPE while Gleason Score (4+3 vs. 3+4) (p = 0.08) and pre-biopsy PSA (p = 0.15) did not reach statistical significance. The median linear distance of EPE was 1.75 mm (Range \1mm-18 mm) The rates of EPE $ 5 mm and EPE $ 3mm were 5.2% and 9.9% respectively. All patients with clinical T1c disease and negative ER-MRI had either organ confined disease 97.2% (69/71) or EPE within 2 mm of the prostatic capsule 2.8% (2/71). Conclusions: In this group of selected men with localized, intermediate-risk prostate cancer, the risk of EPE was associated with clinical T-stage, percent positive core-biopsies, and findings on ER-MRI. Men with the following pre-treatment features: clinical T1c, Gleason 7, PSA \ 10 and negative ER-MRI are likely to have capsule confined disease and no EPE beyond 2 mm was identified in this favorable group. These factors can aid in the appropriate selection of men with intermediate-risk disease for brachytherapy and in designing radiation treatment target volumes. Author Disclosure: T.J. Pugh: None. S.J. Frank: None. M. Achim: None. D.A. Kuban: F. Consultant/Advisory Board; BiotheranosticsFerring Pharmaceutical. A.K. Lee: None. S. Choi: None. Q. Nguyen: None. K. Hoffman: None. S.E. McGuire: None. D.A. Swanson: None.
2394
Application of a Spacer between Prostate and Anterior Rectal Wall to Optimize Radiotherapy of Localized Prostate Cancer: Comparison of Three-dimensional Conformal (3D RT) and Intensity Modulated (IMRT) Treatment Planning Techniques
M. Pinkawa, N. Escobar Corral, M. Caffaro, M. D. Piroth, R. Holy, G. Otto, M. J. Eble RWTH Aachen University, Aachen 52074, Germany