For a medically inoperable clinically-staged FIGO IA endometrial cancer with serous, clear cell or other non-endometrioid, high-risk histology treated with EBRT alone, would you cover elective lymph nodes, or treat the uterus alone?

I would utilize a combination of EBRT and HDR-BT as well as adjuvant chemotherapy, if medically fit for such. If declining brachytherapy, recent reports on SBRT for GYN cancers as a boost modality can help guide planning to avoid excess toxicity risk.

The ESGO/ESTRO guidelines have a section for medi...

It is a function of goals of care and expected survival from co-morbidities and can vary from a short course of palliative RT to definitive RT with EBRT plus some boost with or without chemotherapy.