Transcript Document

Three-Year Analysis of Urinary Toxicity in Two Prospective Trials of Image-guided
Proton Therapy for Early- and Intermediate-Risk Prostate Cancer:
Outcomes in Men with Moderate to Severe Pretreatment Urinary Obstructive Symptoms
Randal H. Henderson, MD, MBA; Zuofeng Li, DSc; Bradford S Hoppe, MD; Robert B Marcus, MD;
William M Mendenhall, MD; R Charles Nichols, MD; Christopher G Morris, MD;
Christopher R Williams, MD; Joseph Costa, DO; Nancy P Mendenhall, MD
University of Florida Proton Therapy Institute, Jacksonville, FL
Introduction
To assess the impact of moderate-to-severe pretreatment
urinary obstructive symptoms on late urinary function and
genitourinary (GU) toxicity in patients treated with imageguided proton therapy for early- and intermediate-risk prostate
cancer.
Methods
One hundred seventy-one prostate cancer patients accrued to
two prospective institutional review board-approved trials of 78
cobalt gray equivalent (CGE) in 39 fractions for low–risk disease
or dose escalation from 78 to 82 CGE for intermediate-risk
disease. Minimum potential follow-up was 3 years. Thirty-two
patients had pretreatment International Prostate Symptom
Score (IPSS) of >15. The IPSS was followed for changes over
time and analyzed as a pretreatment factor against CTCAE v3.0
acute and late GU toxicity.
Results
One low-risk and 1 intermediate-risk patient had disease progression out of the
total 171 patients. Multivariate analysis showed a correlation between GU 2+
symptoms and pre-treatment GU symptom management (p=0.0003), but no
correlation with dose-volume parameters for the bladder and bladder wall. A
total of 58, 54, and 60 patients received alpha-blockers before, during, and after
proton therapy, respectively. There were 18 and 5 patients who received their
first prescription for alpha-blockers during and after radiotherapy, respectively.
Patients with pretreatment IPSS scores of >15 had a decline in
median score from 18 prior to treatment to a median score of 11.5 at 36 months
follow-up. Pretreatment IPSS >15 versus <15 was not associated with a higher
incidence of grade 2+ acute GU toxicity (12% vs. 9%, p=0.7491). The KaplanMeyer 3-year freedom from grade 2+ late GU toxicity was 63% versus 85% (p
=0.0164) and from grade 3 late toxicity it was 100% versus 97% in the two groups
respectively (p=0.3318), and 98% overall. There were no late grade 4 events and
all late grade 3 complications have resolved with time.
Conclusions
Corresponding author Name; 2015 North Jefferson St; [email protected]; 904-588-
1800
Outcomes at 3 years with image-guided proton therapy in doses up to 82 CGE,
based on organ-constraints and the techniques used in this study, continue to
suggest high efficacy and minimal toxicity. Patients with a pretreatment IPSS
score of >15 had significant improvement in median IPSS scores at 36 months,
while patients with pretreatment scores of <15 had no change in median scores.
The low toxicity and improvement in IPSS score in patients with moderate to
severe pretreatment urinary obstructive symptoms may be useful in decisions
regarding the choice of treatment for this group of patients.