When treating rectal cancer with TNT and induction chemotherapy first, do you repeat pelvic MRI prior to planning for chemoradiation?

TNT approach options for pMMR T3, N any; T1–2, N1–2; T4, N any or locally unresectable or medically inoperable rectal cancer patients include:

First chemotherapy for 12-16 weeks (FOLFOX or CAPEOX may also consider FOLFIRINOX) followed by long-course chemoradiation or short-course radiation, followed ...

Yes, I think it is helpful, since induction chemotherapy is several months, to restage to make sure the rectal tumor has either remained stable or regressed, and that nothing is being missed during radiation planning.

This has typically been done by the medical oncologist prior to the consolidative chemoRT approach but data suggests that chemoRT first (prior to chemo alone) is more likely to reduce the need for consolidative surgery (i.e., associated with a higher CR). On another note, and because insurance carri...

No. We looked at this, and we never found a case of progression on FOLFOX. The only scenario I consider restaging with CT torso is if there is a very high nodal burden or EMVI, but that’s to look for new metastases. Don’t need a rectal MRI for that.

Yes, I routinely repeat pelvic MRI prior to the initiation of chemoradiation and prior to evaluation for surgical resection, as it provides a better assessment of the primary tumor and lymph nodes, which can be helpful in local treatment planning.