STANDARD VS CONFORMAL RADIATION-THERAPY FOR ADENOCARCINOMA OF THE PROSTATE - NO DIFFERENCE

Objective: To compare results of treatment of adenocardinoma of the pr ostate using Standard (2D) vs Conformal (3D) treatment planning. Metho ds: The records of all patients with adenocarcinoma of the prostate tr eated curatively with radiation therapy alone from July 1991 to June 1 994 were reviewed. Acute and late complications were scored by the RTO G criteria. Biochemical failure was defined as a rising PSA of at leas t 10% on two measurements separated greater than or equal to 1 month o r either a PSA nadir >4 ng/ml or >1 ng/ml. Disease free survival (DFS) was defined as no evidence of local, distant, or biochemical failure. 2D planning included standard simulation with target volume drawn fro m the treatment planning or diagnostic CT. 3D planning included a CT i n the treatment position with computer simulation using beam's-eye-vie w for field design. Results: Two-hundred and seventeen 2D and 45 3D pa tients had similar median age and pre-treatment PSA, T-stage, and dose to the prostate. The median follow-up periods for the 2D and 3D group s were 32.0 and 21.5 months, respectively. The two-year actuarial surv ival, local or biochemical control, and DFS were not different. The 3D group had a significantly higher incidence of acute bladder side effe cts of all grades and acute grade 1/2 rectal complications. There were no differences in the incidence of late bladder or rectal complicatio ns. Conclusions: Careful 2D planning for the treatment of localized ad enocarcinoma of the prostate is an acceptable means of treatment. With in the dose range of 64-70 Gy, this preliminary analysis demonstrated no reduction in complications nor improvement in local or biochemical control, or DFS was seen with the the use of 3D treatment planning.