What dose is needed for salvage RT for recurrent endometrial cancer in untreated PA region (who has received pelvic RT) after good PET response to systemic therapy?

For a patient with good response to immunotherapy (unable to receive chemotherapy due to kidney function, comorbidities) where previously avid LN have resolved, what dose is needed for microscopic disease? Is 50.4Gy enough or would you boost the previous involved region to a higher dose 54Gy or more?