Long-Term Outcome by Risk Factors Using Conformal High Dose Rate Boost for Prostate Cancer
Reviewer: William Levin, MD
Last Modified: October 8, 2002
Presenter: R. Galalae Presenter's Affiliation: Dept. of Radiation Oncology, Kiel University, Germany Type of Session: Scientific
Radiation therapy is widely used in the treatment of prostate cancer. Forms of this treatment include external beam radiation or brachytherapy, or a combination of the two. With brachytherapy, radioactive seeds are implanted into the prostate gland.
Until recently, the radioactive seeds have remained permanently implanted, giving off energy slowly over time.
Now comes a new technology, high dose rate brachytherapy (HDRB) whereby very powerful radioactive sources are put into the prostate, via catheters, for only several minutes at a time.
This current study reviews the results of the prostate HDRB experience from some of the most well known brachytherapy institutions in the world.
Materials and Methods
This is an analysis of 3 separate trials involving a total of 611 patients with clinically localized prostate cancer.
All patients initially received external beam radiation therapy (EBRT) followed by dose-escalating HDRB.
For analysis, patients were stratified in to risk groups (based on commonly accepted criteria, including, Gleason score (GS), PSA, and clinical stage).
The endpoint was PSA failure, based on the ATRO definition.
Mean follow-up was 5 years (0.2-15.3)
For the 611 patients, biochemical control (BC) at 5 and 10 years were 77% and 73%, respectively. Disease free survival was 67% and 49%.
Group I patients (stage< T2a, GS< 6, PSA<10) had BC of 96%.
Group II patients (stage> T2b, GS> 7, PSA> 10, any one factor) had BC of 87% without hormone therapy and 91% with hormone therapy.
Group III patients (2 or more risk factors described in group II) had BC of 97% without hormone therapy and 90% with hormones.
For groups II & III, regression analysis identified pre-treatment PSA, stage, and Gleason score as predictive for biochemical failure, while the use of hormones was not.
EBRT in combination with high dose rate brachytherapy produced excellent results with regard to biochemical control, even in the group III patients.
The authors also pointed out that these results were all similar between the 3 contributing institutions, highlighting the reproducibility of the findings.
This article suggests that HDRB may be efficacious in the treatment of early-stage prostate cancer.
The authors point out that they are still in the process of determining the optimal dose for HDRB.
Although these findings are encouraging, much longer follow-up is needed to see if the results are equivalent to standard, well established therapies.
Oncolink's ASTRO Coverage made possible by an unrestricted Educational Grant from Ortho Biotech.
Mar 17, 2010 - Compared with standard-dose radiation, high-dose radiation treatments for localized prostate cancer are not associated with increased long-term treatment-related outcomes for urinary, bowel and sexual functions affecting quality of life, according to a study in the March 17 issue of the Journal of the American Medical Association.