RTOG 94-13 is a phase III study designed to determine the appropriate
treatment volume and the optimal way to combine radiation and
total androgen suppression for prostate cancer patients who are
at greater risk of local/systemic failure.
Patients who have localized adenocarcinoma of the prostate and
have an elevated prostate-specific antigen (PSA) level are eligible
for the trial, reports Mack Roach, MD, chair of the study. The
accrual goal is 1,200 patients.
Patients are being randomized to one of four arms:
- Patients in arm 1 of the study will receive flutamide (Eulexin),
two 125-mg capsules three times a day, and goserelin acetate (Zoladex),
monthly for 4 months, beginning 2 months before radiation therapy
and continuing until radiation therapy is completed. Radiation
treatments include whole pelvis irradiation (to 50.4 Gy) followed
by a 19.8-Gy boost to the prostate, to a total dose of 70.2 Gy.
- Patients in arm 2 of the study will receive the same drug
therapy as patients in arm 1. However, they will receive radiation
therapy to the prostate only (to a total dose of 70.2 Gy).
- Patients in arm 3 will undergo whole pelvis irradiation followed
by a boost to the prostate.
- Patients in arm 4 will be treated with radiation therapy to
the prostate only.
In both arms 3 and 4, flutamide and goserelin are being given
for 4 months once radiation therapy is completed.
"This study allows us to answer the critical question of
whether whole pelvis irradiation plus a boost improves the progression
free-survival of these patients," says Dr. Roach.
"It also allows us to test the hypothesis that flutamide
and Zoladex are more effective if they are administered before
and during radiation therapy rather than after radiation treatments,"