Prelimimary results of a randomized dose-escalation study comparing 70 Gy to 78 Gy for the treatment of prostate cancer
Albert DeNittis, MD
OncoLink Assistant Editor
Last Modified: November 1, 1999
Presenter: Alan Pollack Affiliation: MD Anderson Cancer Center
Summary: - The purpose of this study was to compare the impact of 70 Gy versus 78 Gy on relapsing/rising PSA and biopsy positivity.
298 patients were enrolled in a single institution randomized clinical trial comparing 70 Gy vs. 78 Gy in the treatment of prostate cancer.
Patients were eligible if they had T1-T3 disease, no history of pelvic radiation therapy or androgen ablation
Treatments consisted of 70 Gy using a four field technique. Initial fields were treated to 46 Gy to the whole pelvis with a boost to prostate and seminal vesicles with 24 Gy. The 78 Gy arm used a 6 field arrangement initially to 46 Gy with a boost to the prostate and seminal vesicles. The 76 Gy isodose line covered the prostate.
Demographics were equal for both groups
Median follow up was 40 months for the entire group and median PSA was 7.8
Freedom from failure (FFF) at 5 years was 79% for 78 Gy compared to 69% for 70 Gy. This was of borderline statistical significance.
Multivariate analysis demonstrated that PSA, stage, and gleason score were all significant factors.
T1/T2 patients had a FFF rate at 5 years of 87% for 78 Gy and 77 % for 70 Gy.
T3 patients had a 61% FFF for 78 Gy and 35% for 70 Gy.
For Gleason <6 the 5 year FFF was 93% and 75% for 78 Gy and 70 Gy respectively.
Pretreatment PSA <10 was not significant. For PSA >10 there again was a significant FFF at 5 years. For 78 Gy it was 75% versus 48% for 70 Gy.
In addition there was no significant difference in freedom from distant metastases (FFDM) for patients with PSA >10. However there was a trend which would suggest an effect on biochemical failure that translates into decreased DM.
The probability of positive biopsy was not significantly different between the two groups. Both groups had a positive biopsy of 30%.
The preliminary results of this dose escalation study indicate that for patients with PSA>10 or T1/T2 disease NED rates are improved
In addition the data suggests a difference in FFDM
It seems that for this study the intermediate risk patient benifits from dose escalation however further dose escalation studies are needed.
Oct 4, 2011 - For patients with rectal cancer, preoperative treatment with a combination of capecitabine and radiation at 50 Gy is associated with favorable outcomes at three years, according to a study presented at the annual meeting of the American Society for Radiation Oncology, held from Oct. 2 to 6 in Miami Beach.