In a nutshell
The authors evaluated the long-term results of escalating high dose radiotherapy for localized prostate cancer.
Some background
In the treatment of localized prostate cancer (cancer that has not spread beyond the prostate), improved radiotherapy techniques such as conformal radiotherapy allow high treatment doses to be given safely. In conformal radiotherapy, a number of radiation beams are used, from different angles, so that the irradiated area fits exactly to the shape of the tumor, while sparing the surrounding tissue. This allows for a higher amount of radiation to be targeted at the tumor, while reducing the toxicity to surrounding tissues.
This study evaluated the long-term effect of administering conformal radiotherapy at higher than standard dosages.
Methods & findings
843 men were randomly assigned to receive either escalated-dose conformal radiotherapy (422 men who received a total of 74 Grays of radiation in 37 courses) or control-dose conformal radiotherapy (421 men who received the standard 64 Grays of radiation in 32 standard courses). All patients also received androgen deprivation therapy (intended to reduce the production of male sex hormones such as testosterone, or inhibit their effect on cancer cell growth) for 3-6 months before the start of radiotherapy. Androgen deprivation therapy was continued until the end of radiotherapy. The average follow-up was 10 years.
By the end of the study 236 deaths occurred, 118 in each group. 10-year overall survival was 71% in both treatment groups. Overall, biochemical progression free survival (survival without a rise in prostate specific antigen levels following treatment) at 10-years was 43% in the control group and 55% in the escalated dose group.
The bottom line
The authors concluded that although escalating-dose conformal radiotherapy showed an advantage in biochemical progression-free survival rates, this advantage did not translate into an improvement in overall survival. Therefore, this treatment option must be weighed against the increase in toxic side effects associated with the escalated dosages of radiation.
The fine print
The article did not include information regarding the type or frequency of adverse side effects experienced.
Published By :
Lancet oncology
Date :
Feb 25, 2014
