Update of the Results of the Dutch Multicenter Dose Escalation Trial of Radiotherapy for Localized Prostate Cancer
Improved radiation techniques (IMRT and 3D conformal radiation therapy) have allowed for higher doses of radiation to be given in the treatment of prostate cancer. This study updated a previous report which showed that a higher dose of radiation resulted in improved "freedom from failure" (FFF) compared to traditional doses (64% vs. 54%). FFF was defined as clinical or biochemical failure, which was defined as three consecutive increases in PSA level after a nadir and a PSA greater than the nadir plus 2 ng/ml.
This report has a median follow up of 69 months and continues to show benefit in FFF (57% versus 45%). Despite this, there is no difference in the overall survival of the groups. There appears to be the most benefit to those classified as intermediate risk.
This trial employs 3D-CRT to achieve higher doses to the target tissue area while minimizing normal tissue doses, and it demonstrates that dose escalation does improve FFF. At a median follow-up of 69 months, no benefit to dose escalation was demonstrated in FFCF (freedom from clinical failure) or overall survival. Larger trials with longer follow-up are needed to determine if this benefit in FFF will result in improvements in the rates of clinical failure and overall survival over time. Larger trials are also needed to determine which risk group of patients should receive dose escalation, as no statistically significant difference was seen in this study when comparing doses within each risk group, likely due to the small sample sizes.
Partially funded by an unrestricted educational grant from Bristol-Myers Squibb.