Erectile Dysfunction (ED) after Radiotherapy (RT) for Prostate Cancer William M. Mendenhall, MD
Meta-Analysis of Probability of Maintaining Erectile Function after Treatment of Localized Cancer Treatment Patient no. 1-yr post treatment Patient no. 2-yrs post treatment BT Alone 172 76% No data No data 80% BT + EBRT 58 60% 58 60% 69% EBRT 1343 55% 731 52% 68% RP-Nerve Sparing 485 34% 128 25% 22% RP-Standard 3019 25% 2673 25% 16% Cryotherapy 264 13% 198 15% 13% Abbreviations: BT, brachytherapy; EBRT, external beam radiotherapy; RP, radical prostatectomy Age adjusted Robinson JW, Moritz S, Fung T. Meta-analysis of rates of erectile function after treatment of localized prostate carcinoma. Int J Radiat Oncol Biol Phys. 2002 Nov 15;54(4):1063-8. PubMed PMID: 12419432.
Probability of Developing Erectile Dysfunction Due to RT Probably Plateaus after 2 to 3 Years
Etiology of Post-RT ED Conflicting data suggest that RT may damage the internal pudendal artery, posterior neurovascular bundles, and/or penile bulb Precise etiology remains unclear Mendenhall WM, Henderson RH, Indelicato DJ, Keole SR, Mendenhall NP. Erectile dysfunction after radiotherapy for prostate cancer. Am J Clin Oncol. 2009 Aug;32(4):443-7. doi: 10.1097/COC.0b013e318173a563. Review. PubMed PMID: 19657239.
Etiology of Post-RT ED Scatter radiation to testicles may cause decreased testosterone in patients treated with photon external beam RT (EBRT) Proton RT to prostate alone or prostate and proximal seminal vesicles does not result in decreased testosterone Nichols RC Jr, Morris CG, Hoppe BS, Henderson RH, Marcus RB Jr, Mendenhall WM, Li Z, Williams CR, Costa JA, Mendenhall NP. Proton radiotherapy for prostate cancer is not associated with post-treatment testosterone suppression. Int J Radiat Oncol Biol Phys. 2012 Mar 1;82(3):1222-6. doi: 10.1016/j.ijrobp.2010.12.025. Epub 2011 May 11. PubMed PMID: 21570206. Kil WJ, Nichols RC Jr, Hoppe BS, Morris CG, Marcus RB Jr, Mendenhall W, Mendenhall NP, Li Z, Costa JA, Williams CR, Henderson RH. Hypofractionated passively scattered proton radiotherapy for low- and intermediate-risk prostate cancer is not associated with post-treatment testosterone suppression. Acta Oncol. 2013 Apr;52(3):492-7. doi: 10.3109/0284186X.2013.767983. PubMed PMID: 23477360; PubMed Central PMCID: PMC3613975.
Post-Proton RT Testosterone Levels UFHPTI 207 patients with median pre-rt testosterone of 367.7 ng/dl Low or intermediate prostate cancer No androgen deprivation No testosterone supplements 70 to 72.5 Gy at 2.5 Gy/Fx Prostate or prostate and 2 cm proximal seminal vesicles 2008 to 2011 Kil WJ, Nichols RC Jr, Hoppe BS, Morris CG, Marcus RB Jr, Mendenhall W, Mendenhall NP, Li Z, Costa JA, Williams CR, Henderson RH. Hypofractionated passively scattered proton radiotherapy for low- and intermediate-risk prostate cancer is not associated with post-treatment testosterone suppression. Acta Oncol. 2013 Apr;52(3):492-7. doi: 10.3109/0284186X.2013.767983. PubMed PMID: 23477360; PubMed Central PMCID: PMC3613975.
Post-Proton RT Testosterone Levels None of these changes were statistically significant Interval Patient no. Median post-rt change Treatment completion 207-3.0 ng/dl 6 months 165-6.0 ng/dl 12 months 116 + 5.0 ng/dl Kil WJ, Nichols RC Jr, Hoppe BS, Morris CG, Marcus RB Jr, Mendenhall W, Mendenhall NP, Li Z, Costa JA, Williams CR, Henderson RH. Hypofractionated passively scattered proton radiotherapy for low- and intermediate-risk prostate cancer is not associated with post-treatment testosterone suppression. Acta Oncol. 2013 Apr;52(3):492-7. doi: 10.3109/0284186X.2013.767983. PubMed PMID: 23477360; PubMed Central PMCID: PMC3613975.
Prevention of Post-RT ED Daily Tadalafil (Cialis) on Sildenafil (Viagra) Limit RT to moderate and high risk volumes based on nomograms i.e. MSKCC, Partin Tables Limit addition and duration of ADT Testosterone supplementation for low and intermediate risk patients after RT Abbreviation: ADT, androgen deprivation therapy
RTOG 0831 242 patients between 2009 and 2012 Intact erectile function EBRT, 63%; brachytherapy (BT), 37% Randomized to 24 weeks of Cialis 5 mg per day or placebo Erectile function (EF) was assessed prior to RT, at weeks 2 and 4, and between weeks 20 and 24 Primary outcome was EF between weeks 28 and 30 after initiation of RT; secondary endpoints included EF at 1 year Assessed with International Index of Erectile Function Pisansky TM, Pugh SL, Greenberg RE, Pervez N, Reed DR, Rosenthal SA, Mowat RB, Raben A, Buyyounouski MK, Kachnic LA, Bruner DW. Tadalafil for prevention of erectile dysfunction after radiotherapy for prostate cancer: the Radiation Therapy Oncology Group [0831] randomized clinical trial. JAMA. 2014 Apr 2;311(13):1300-7. doi: 10.1001/jama.2014.2626. PubMed PMID: 24691606.
RTOG 0831 There was no significant improvement in EF at 28 to 30 weeks or at 1 year between daily Cialis and placebo Pisansky TM, Pugh SL, Greenberg RE, Pervez N, Reed DR, Rosenthal SA, Mowat RB, Raben A, Buyyounouski MK, Kachnic LA, Bruner DW. Tadalafil for prevention of erectile dysfunction after radiotherapy for prostate cancer: the Radiation Therapy Oncology Group [0831] randomized clinical trial. JAMA. 2014 Apr 2;311(13):1300-7. doi: 10.1001/jama.2014.2626. PubMed PMID: 24691606.
MSKCC-Mt. Sinai Trial 202 patients with localized prostate cancer RT with EBRT (21%), BT (44%), or EBRT and BT (35%) ADT (10%) 2:1 randomization to Viagra 50 mg/day or placebo beginning 3 days prior to RT and continuing for 6 months EF was assessed with IIEF at 3, 6, 9, 12, 18, and 24 months after RT Zelefsky MJ, Shasha D, Branco RD, Kollmeier M, Baser RE, Pei X, Ennis R, Stock R, Bar-Chama N, Mulhall JP. Prophylactic sildenafil citrate improves select aspects of sexual function in men treated with radiotherapy for prostate cancer. J Urol. 2014 Sep;192(3):868-74. doi: 10.1016/j.juro.2014.02.097. Epub 2014 Mar 3. PubMed PMID: 24603102.
MSKCC-Mt. Sinai Trial 12-month Outcomes Better likelihood of mild or no ED with Viagra (73% vs 50%; p=.024) Better overall satisfaction with Viagra (p=.027) Better IIEF scores with Viagra (p=.043) Zelefsky MJ, Shasha D, Branco RD, Kollmeier M, Baser RE, Pei X, Ennis R, Stock R, Bar-Chama N, Mulhall JP. Prophylactic sildenafil citrate improves select aspects of sexual function in men treated with radiotherapy for prostate cancer. J Urol. 2014 Sep;192(3):868-74. doi: 10.1016/j.juro.2014.02.097. Epub 2014 Mar 3. PubMed PMID: 24603102.
MSKCC-Mt. Sinai Trial 12-month Outcomes EF (p=.172) and IIEF (p=.09) were no different Overall satisfaction was higher with Viagra (p=.033) Functional erection without meds was 81.6% in the Viagra arm (having been off Viagra for 18 months) and 56.0% in the placebo arm (p=.045) Zelefsky MJ, Shasha D, Branco RD, Kollmeier M, Baser RE, Pei X, Ennis R, Stock R, Bar-Chama N, Mulhall JP. Prophylactic sildenafil citrate improves select aspects of sexual function in men treated with radiotherapy for prostate cancer. J Urol. 2014 Sep;192(3):868-74. doi: 10.1016/j.juro.2014.02.097. Epub 2014 Mar 3. PubMed PMID: 24603102.
NCCN Risk Groups Low T 1C to T 2A, PSA <10, GS<6 Intermediate T 2B to T 2C or PSA 10.1 to 19.9 or GS 7 High - >T 3A or PSA >20 or GS >8 GS, Gleason score
Limiting RT Volumes CT simulation fused with MR MR better identifies apex and base CT overestimates size of prostate Low risk prostate with 4 to 6 mm margins Intermediate risk prostate and 2 cm proximal SV High risk Risk of positive nodes <15% - prostate and proximal SV Risk of positive nodes >15% - prostate, proximal seminal vesicles, and pelvic nodes CT, computed tomography; MR, magnetic resonance; SV, seminal vesicles
Elective Pelvic Node Irradiation (ENI) ENI reduces risk of pelvic node recurrence ENI probably does not improve survival Consider ENI when risk of positive nodes >15% based on Partin tables and MSKCC nomogram Mendenhall WM, Hoppe BS, Nichols RC, Henderson RH, Mendenhall NP. When is elective pelvic lymph node irradiation indicated in definitive radiotherapy for localized prostate cancer? Am J Clin Oncol. 2013 Dec;36(6):644-7. doi: 10.1097/COC.0b013e31823a53fa. Review. PubMed PMID: 22237149.
Proton RT Intermediate Risk UFHPTI 536 patients between 2006 and 2010 98% received 78 to 82 Gy at 2 Gy/Fx Treatment planning CT fused with MR Protons alone to prostate and proximal 2 cm of seminal vesicles with 4 to 6 mm margins 9.7% received ADT Median follow-up 4.9 years Treatment planning CT fused with MR Bryant C, Mendenhall WM, Hoppe BS, Henderson RH, Nichols RC, Morris CG, Williams CR, Su Zhong, Li Z, Mendenhall NP. Biochemical Outcomes for Patients with Intermediate-risk Prostate Cancer Treated with Proton Therapy. 2015; in process.
Proton RT Intermediate Risk UFHPTI T 2 34% PSA 10.1 to 19.9 26% GS 4+3 27% >2 intermediate risk factors 22% Bryant C, Mendenhall WM, Hoppe BS, Henderson RH, Nichols RC, Morris CG, Williams CR, Su Zhong, Li Z, Mendenhall NP. Biochemical Outcomes for Patients with Intermediate-risk Prostate Cancer Treated with Proton Therapy. 2015; in process.
Proton RT Intermediate Risk UFHPTI 5-year outcomes Percent bpfs 95.4% DMFS 98.9% CSS 99.6% OS 95.3% Abbreviations: bpfs, biochemical progression; DMFS, distant metastasis-free survival; CSS, cause-specific survival; OS, overall survival MVA > intermediate risk factors associated with increased risk of biochemical failure ADT did not improve 5-year bpfs Abbreviations: MVA, multivariate analysis Bryant C, Mendenhall WM, Hoppe BS, Henderson RH, Nichols RC, Morris CG, Williams CR, Su Zhong, Li Z, Mendenhall NP. Biochemical Outcomes for Patients with Intermediate-risk Prostate Cancer Treated with Proton Therapy. 2015; in process.
Proton RT High Risk UFHPTI 245 patients between 2006 and 2010 94% received >78 Gy Protons alone to prostate and proximal seminal vesicles (83%) or combined with IMRT to pelvic nodes (17%) ADT was recommended to all and received by 67% (59% for 6 months; 8% for >18 months) Concomitant weekly docetaxel 26% Abbreviation: IMRT, intensity-modulated radiotherapy Bryant C, Mendenhall WM, Hoppe BS, Henderson RH, Nichols RC, Morris CG, Williams CR, Su Zhong, Li Z, Mendenhall NP. Biochemical Outcomes for Patients with Intermediate-risk Prostate Cancer Treated with Proton Therapy. 2015; in process.
Proton RT High Risk UFHPTI T-stage T 1C 49% T 2A -T 2B 36% T 2C 8% T 3 7% Gleason Score 6-7 16% 8 53% 9-10 31% PSA <10 59% 10-20 18% >20 23% Bryant C, Mendenhall WM, Hoppe BS, Henderson RH, Nichols RC, Morris CG, Williams CR, Su Zhong, Li Z, Mendenhall NP. Biochemical Outcomes for Patients with Intermediate-risk Prostate Cancer Treated with Proton Therapy. 2015; in process.
Proton RT High Risk UFHPTI 5-year outcomes Percent bpfs 74% DMFS 86% CSS 96% OS 88% Docetaxel was not associated with improved outcomes Pelvic node RT did not result in improved bpfs (64% with ENI; 76% without ENT; p=.09) Bryant C, Mendenhall WM, Hoppe BS, Henderson RH, Nichols RC, Morris CG, Williams CR, Su Zhong, Li Z, Mendenhall NP. Biochemical Outcomes for Patients with Intermediate-risk Prostate Cancer Treated with Proton Therapy. 2015; in process.
Erectile Function after Proton RT UFHPTI 255 men <60 years Low risk 143 patients Intermediate risk 106 patients High risk 6 patients No ADT Potency = erection firm enough for sexual intercourse Baseline and follow-up with Expanded Prostate Index Composite (EPIC) Median follow-up 5 years Ho et al. 2015.
Erectile Function after Proton RT UFHPTI 5-year bpfs, 98.6% 5-year overall survival, 99.2% 5-year CSS, 100% 3 patients who failed (1 high risk, 2 intermediate risk) were alive at 5 years. Ho et al. 2015.
Erectile Function after Proton RT UFHPTI Median sexual function score declined from 84 at baseline to 69 after 2 years and then stabilized Potency declined from 90% at baseline to 71% at 2 years and stabilized at 66% MVA EPIC sexual summary score was the only factor associated with potency (p.0002) 5 year potency rates were: Baseline score Potency 100 88% 99-68 61% <68 40% Ho et al. 2015.
Erectile Dysfunction after RT Testosterone Supplementation If a low or intermediate risk patient is biochemically disease free after RT with a testosterone level of 500, would you initiate treatment (ADT) to lower it? If not, then why would you not place a similar patient with a testosterone of 150 on a testosterone supplement?
Erectile Dysfunction after RT Testosterone Supplementation Androgel Daily Depotestosterone IM every 1 to 2 weeks
Erectile Dysfunction after RT UFHPTI 23 patients s/p proton RT (2006-2012) and biochemically disease free Low risk 9 patients Intermediate risk 12 patients High risk 2 patients Low serum testosterone with symptomatic hypogonadism Median follow-up, 38 months; median follow-up after testosterone supplementation, 14 months Bryant C, Hoppe BS, Mendenhall NP, Henderson RH, Nichols RC, Morris CG, Williams CR, Su Z, Li Z, Mendenhall WM. Testosterone Replacement Therapy in Men with Prostate Cancer after Proton Therapy. Int J Particle Ther. 2014;1(3):682 691.
Erectile Dysfunction after RT UFHPTI After 1 to 6 months on testosterone supplements, median serum testosterone level increased from 238 to 497 No patient experienced biochemical failure Median PSA did not rise Median EPIC sexual summary, sexual function, and sexual bother scores all increased Potency rates increased from 50% to 68% after 7 months No cardiac complications Bryant C, Hoppe BS, Mendenhall NP, Henderson RH, Nichols RC, Morris CG, Williams CR, Su Z, Li Z, Mendenhall WM. Testosterone Replacement Therapy in Men with Prostate Cancer after Proton Therapy. Int J Particle Ther. 2014;1(3):682 691.
Erectile Dysfunction after RT Probability of ED after RT is about 25 to 30% Mechanism is unclear Baseline EPIC sexual summary score is most predictive post-rt protency Unclear whether significant decrease in RT volume reduces risk of ED (but it results in decreased risk of other complications) Unclear whether erectile aids (i.e., Cialis; Viagra) reduces risk of ED Testosterone supplementation is probably safe and improves potency for low-intermediate risk patients with low testosterone levels
Erectile Dysfunction after RT Like many things in life Use it or lose it!