Getting started early with salvage radiation improves the odds of success, yet another study shows. In this study, an important PSA cutpoint was shown to be 0.25 ng/ml:
"In a study reported in the Journal of Clinical Oncology, Derya Tilki, MD, and colleagues identified a prostate-specific antigen (PSA) level cutpoint, above which initiation of salvage radiation therapy after radical prostatectomy was associated with an increased risk of all-cause mortality in patients with prostate cancer." Source: The ASCO Post, March 7, 2023. https://ascopost.com/news/march-2023/psa-level-at-time-of-salvage-radiation-therapy-after-radical-prostatectomy-and-risk-of-all-cause-mortality/
In my case, because my urologist wasn't watching me like a hawk, and because Christmas and New Year's hit at the time I was trying to make appointments, I started SRT much later than 0.25. I was fortunate that it still worked, and apparently cured my cancer.