The engineer in me is alive and well. In preparation for starting salvage radiation therapy next week, I’ve started experimenting with the timing and volume of water needed to have a full bladder at just the right time.

The instructions I was given were to drink a liter of water and have completed doing so by 30 to 45 minutes before my scheduled appointment time. Because I can’t drink an entire liter in one shot, I give myself about 30-40 minutes to do so. I also created two rating scales (purely subjective, of course).

The first rating scale is the sense of urgency that I have at the scheduled start time of the zapping. I use a scale of 1 to 10, with one being, “I got this,” to ten being, “Get outta my way I’m gonna to pee in my pants!!” The second scale is an estimate of volume when I finally do empty my bladder. (During my mapping, we had to wait because my bladder wasn’t full enough.)

For reference, my zapping appointments are scheduled at 9:45 a.m. I figure that I’ll have to hold my bladder until at least 10:15 a.m. to allow for getting me aligned and get through the actual zapping itself.

Yesterday, my first experiment day, I started drinking at 8:45 a.m. and had consumed the full liter by 9:15 a.m., 30 minutes before the scheduled zapping start time. At 9:45 a.m., I rated my urgency at a 5 and, interestingly, I was able to not empty my bladder until 10:45 a.m. However, I was surprised that the volume was lower than I expected it and rated it a 5 (out of 10). I suspect that would have delayed the zapping a bit.

Today, I started drinking a little earlier at 8:35 a.m. in hopes of having a more full bladder. I stopped drinking at 9:10 a.m., 35 minutes before the scheduled start time. At 9:45 a.m., I rated my urgency as a 7 and had to empty my bladder at 10:15 a.m., with a higher volume output than the day before (also rated a 7).




at 9:45 a.m.

Need to


30 June






1 July






I’ll continue to do this up until the start date to try and zero in on the perfect timing so the zapping goes as smoothly as possible once it starts next Thursday.

Yes, I’m a nerd.

Be well!

This post originally appeared on Dan’s Journey Through Prostate Cancer on July 1, 2022. It is republished with permission.