Progress in 3D conformal radiation treatment of prostate cancer

The development of 3D conformal radiation is reviewed and the proof given of three key hypotheses that result in improved patient results. The Fox Chase outcomes from 3D CRT show 7- and 8-year biochemical freedom of disease rates of 72% for all patients, 84% for PSA < 10 ng/ml, 73% for PSA 10-19.9 ng/ml and 37% for PSA > 20 ng/ml. Dose responses by pretreatment PSA level grouping show steep slopes for patients with PSA> 10 ng/ml. Dose response is also demonstrated for 'favorable' and 'unfavorable' prognostic subgroupings of the classic three pretreatment PSA groups. A matched pair analysis of high-dose 3D CRT versus low-dose 3D CRT shows on multivariate analysis a significant advantage in freedom from distant metastasis. A similar matched comparison of high-dose 3D CRT with low-dose 3D CRT patients and low-dose conventional technique patients shows a significant advantage in distant metastasis, cause-specific survival and overall survival for the high-dose group. Future studies including those using biochemical endpoints to direct differential dose distributions are discussed.