@ambika FYI - The amount of water recommended is highly variable. In my case, I apparently tend to absorb water rapidly, reducing the amount getting to the bladder. As a result, I am required to drink 32oz of water prior to treatment (luckily, I am allowed to include my morning coffee in that total). In re the spacer, I am undergoing proton beam therapy, and the protocol empoyed is a combination of features of BioProtect and SpaceOAR. BioProtect employs a balloon inserted rectally, which allows flexibility in adjusting the location of the spacer. After positioning, the balloon is filled with a biodegradable gel. Both the gel and the balloon are biodegradable. SpaceOAR injects the gel directly, and once injected, its location cannot be adjusted. In my treatment, a biodegradable gel is directly injected before the start of treatment. Then, each day (5 days/week) after positioning on the table, a balloon is inserted, positioned and inflated, providing additional space, before the treatment starts. The balloon is removed after treatment.