What factors do you use to determine whether to add brachytherapy to EBRT for IIIC endometrial cancer?

My philosophy is to use 45 Gy in 25 fractions of EBRT followed by two fractions HDR boost.

Nothing in the way of prospective data, but an NCDB analysis showed a survival benefit in adding brachy to EBRT for patients with cervical gland/stromal involvement

We would tailor the external beam dose and brachytherapy to the factors identified on the pathology report. IIIC covers many situations.

For a tumor up at the fundus, and grade 1 we might treat with external beam therapy alone and omit the brachytherapy.

If there was evidence of parametrial extensi...