Once the patient is a candidate for rSBRT, the patient is scheduled for his fiducial placement and simulation. We used specific four golden fiducials manufactured to be used with CyberKnife^® (Fig. 18.2). Prophylactic antibiotic and urinary antiseptics are given prior to procedure.

At our institution, the fiducials are inserted transrectally under ultrasound guidance by the urologist under local anesthesia (Fig. 18.3). We also try to place the fiducials in certain regions of the prostate gland due to the fact that all fiducials should be in certain geometry accordingly with the imaging X-ray tubes (Fig. 18.4). Once the fiducials have been placed, there should be 7–10 days before the simulation is done.

For the simulation, we place the patient in a supine position and place a 14 Gauge Foley catheter into the bladder to visualize prostatic urethra (Fig. 18.5). We then inflate its balloon with 6 cc of water. Once the Foley is placed, a non-contrast planning CT with less than 1 mm slice thickness is performed to the entire pelvis.

At our institution, the CTV for definitive prostate cancer patients is as per the following: prostate only for low risk; prostate proximal seminal vesicles (SV) for intermediate risk. Proximal is defined as the proximal 1 cm of the SV.

The standard dose is 36.5 Gy in 7.3 Gy daily fractions either in consecutive (Monday–Friday) or every-other-day regimen (2 weeks regimen) (Fig. 18.6).

Our rSBRT treatment plan acceptance criteria are summarized as following: