Dose Escalation with High-Dose-3D-Conformal/IMRT (HD-3D-CRT/IMRT) Compared with Low-Dose 3D-Conformal/IMRT Plus HDR Brachytherapy (LD-3D-CRT/IMRT+HDR-B) for Intermediate- or High-Risk Prostate Cancer: Higher Disease Control and Survival with Lower Toxicity