@surftohealth88 They usually don’t use fiducials since SRT is not very targeted as SBRT would be…daily cone beam (similar to CAT) before treatment verifies position of bed, bladder, rectum, etc.
My RO said no spacer allowed since rogue PCa cells might be close to rectum; don’t want to block those from being hit.
As has been said in other posts, the ‘simulation’ visit, where you are given water to drink (after emptying the bladder) so they - and you! - get an idea of how much to drink and how long it takes to reach the bladder to fill it to the max, is very important.
This will tell you how much and how far in advance of your daily session you need to drink in order to get that bladder to swell.
Also, your husband will take an enema before the simulation, so the rectum is empty and narrow in diameter.
This allows the radiation software to ‘shape’ the beam around it, hitting it 360 degrees; so the radiation gets close!
These 3D measurements (full bladder/empty rectum) are integrated into the treatment software and will be used DAILY during treatment.
If the cone beam pre-treat scan shows any deviation from these set parameters - ie. Bladder not full enough or rectum distended - treatment will be delayed or sometimes even cancelled. We call it ‘being kicked off the table’. One time they said I had a huge gas bubble (felt nothing) and they told me to walk around, do jumping jacks - anything to get it to move…nothing worked until they finally handed me a Fleet Enema and that did the trick.
In fact, I started carrying one of my own since radiation dept had to get an RX from the RO to get me one…took 45 minutes to do that!
So my 20 min visit turned into almost 2 hours😩
Phil