Make room.

The next iteration of rectal spacers for prostate radiation are iodinated. When you think about it, you wonder why this wasn’t always the case for something designed for CT-based treatments. Nonetheless, they’re here now and this study takes a look at 50 patients treated with iodinated spacers and 50 with old-school non-iodinated spacers to quantify just how much easier it is to see on CT simulation and even cone beam CT used for alignment. Iodinated spacers had a mean Houndsfield units (HU) of 138 while the non-iodinated version had a mean HU of only 12. What’s more, prostate-rectal separation was similar whether iodinated or non-iodinated spacer was used, and there was no significant change in HU, volume, surface area, or relative position of the non-iodinated spacer from sim to final treatment. All this points to there being no relative disadvantage to using an iodinated versus non-iodinated spacer with the obvious advantage of ease of visibility. TBD: the clinical advantage to using any spacer at all. | Kamran Pract Radiat Oncol 2021