Three-dimensional conformal RT (3DCRT), intensity-modulated RT (IMRT), proton therapy, and stereotactic body RT (SBRT).

1. 3DCRT, developed in the 1990s, incorporated computed tomography (CT)-based treatment planning and decreased the risk of toxicity compared to conventional 2D techniques, allowing for dose escalation and improved biochemical control.
   
2. IMRT uses CT-based inverse treatment planning, permitted by the invention of the multileaf collimator, to modulate the intensity of the radiation beam over small surface areas. This allows for steep dose gradients, further reduces dose exposure to adjacent organs at risk (bowel, bladder, rectum, penile bulb, and femoral heads), and is currently considered the standard of care.
   
3. SBRT uses larger doses per fraction (also known as “extreme hypofractionation”) with the advantage of a higher biologic effective dose (BED) and a lower total number of treatments, generally five (compared to 8–9 weeks of IMRT). Limited data, primarily in the low-risk setting, are available with relatively short follow-up. Most studies show >93% biochemical control rates with acceptable acute toxicity. Late and extended follow-up toxicity rates are awaited, particularly in the collaborative group setting.
   
4. Loma Linda has published its long-term results of patients treated with proton therapy, showing comparable treatment outcomes to IMRT. A multi-institutional trial (NCT01617161) is currently assessing whether there are any clinically relevant differences compared to IMRT that are of particular interest due to the higher cost of proton therapy compared to IMRT.

All of the above technologies are employed with daily image-guided RT (IGRT) techniques to verify patient and prostate positioning, such as cone beam CT, ultrasound, an endorectal balloon, or fiducials implanted in the prostate prior to treatment initiation with daily kilovoltage orthogonal imaging.