10+ Year Member
- Jan 10, 2010
- Reaction score
use of composite endpoints to increase power are well-accepted in RCTs. I see TTB as a composite endpoint to capture all the toxicities a patient experiences, but weighted by their burden on the patient. With conventional toxicity outcomes, we usually ignore anything less than grade 3, and make it binary such that a patient who has three grade 3 GI toxicities is counted the same as someone who has one grade 3 GI toxicity. I think the conventional outcomes as described have a high risk of measurement bias. TTB could as well, but I think it’s probably better at measuring what we are interested in.
To be honest as a non-radonc this is one of my biggest gripes against the field and interpretation of studies. Your grade 2 toxicity that is poo-pood or seen as irrelevant is my patient that I'm seeing q6m for the rest of their lives, putting them on anticholinergics (which likely exacerbate their cognitive decline) or having them pay $$$ for B-3 agonists, or catheterizing them and dealing with their recurrent UTIs (which significantly effects QOL) etc.
Likewise when I listened to a lecture where prostate hypofx was discussed, while the overall thesis was "its so much faster with similar toxicity" I came out from looking at the data thinking that If I got xrt I'd take conventional fractionation 10/10 times. I'd much rather get an extra 20 treatments then take the additional risk of dealing with symptoms lifelong.