Top Line: No one likes prepping for a consult and discovering evidence of locally-recurrent prostate cancer after...dun dun dun….previous definitive radiation.
The Study: Any further radiation, or even salvage surgery for that matter, in a previously-irradiated field just sounds bad. But where’s the data? Here is a huge, one might say MASTER, meta-analysis of 150 studies (n=11,332) examining efficacy and toxicity of various salvage options following definite prostate radiation. Considering what you started with, recurrence-free survival at 5 years (adjusted for factors such as age, PSA, ADT, median time to salvage, and study type) was an impressive 53% for salvage radical prostatectomy, 53% for LDR brachy, 58% for HDR brachy and 56% for SBRT. Where things began to differ was on the toxicity side of the equation. Salvage radiation, whatever its form, carried less than half the adjusted risk of overall grade 3+ GU toxicity: 21% for salvage surgery, 8% for LDR brachy, 8% for HDR brachy, and 4% for SBRT. Adjusted grade 3+ GI toxicity also favored HDR brachy and SBRT, which resulted in zero reported cases among 832 patients, versus surgery with a risk of 2%. A final note is, now that we have an idea of the risk involved with various salvage options, the best way to maximize effectiveness remains identifying those with truly localized disease via tools like advanced imaging.
TBL: Radiation on radiation isn’t always terrible and, in the case of locally-recurrent prostate cancer, may even offer the best balance of efficacy and toxicity. | Valle, Eur Urol 2020