Do you use the re-radiation schedule 39Gy in 26 fx BID for a rectal patient who initially received 25 Gy in 5 fractions and then has pelvic recurrence?

We have retreated rectal cancer patients with pelvic reRT (using protons) with doses as high as 39-45 Gy BID after both conventional fractionation and 25 Gy/5fx. In patients with prolonged interval since the original RT, no other sites of disease, good ECOG, and no good systemic/surgical options, th...

Would not use the hyper fractionation approach for re-irradiation but would use standard fraction chemo radiation with IMRT to deliver 20-40 Gy preoperatively (higher dose only if small bowel could be avoided after 20Gy). Would then restage to rule out extra pelvic disease and proceed to resection a...

If one believes the linear quadratic equation, the BED to a/b=3 tissue with 50.4/28 fx would be ~80, while 25/5 it would be ~67. If accounting for team, it seems to be quite close.

There are several series showing efficacy/safety with BID reirradiation to doses of 30-39 Gy, so it would not be unreas...

You could. It won’t be controlled and the patient will likely die a miserable death. Don’t stent the ureters.