Radiotherapy may produce an increased vaginal discharge.
The treatment is killing the cells which are then being discharged.
This is known as local toxicity due to chemoradiotherapy.
Your cervix is now more vulnerable and susceptible to genital infection, too.
It could be expected for normal vaginal flora balance to be changed due to therapy, too.
Have you been taken sample for microbiological testing?
Do you feel burning sensation when passing urine?
Do you have frequent need to urinate?
Is the discharge with fishy odor?
Do you often get vaginal itchiness?