Thanks for your question on Health Care Magic.
I can understand your sister's situation and problem.
Radiotherapy causes tissue damage, destruction and fibrosis. So pain is common symptom after radiotherapy.
For lower limb swelling, following are possible causes in her case.
1.
Lymphedema due to metastatic involvement of inguinal lymphnodes.
Cervical cancer is known to spread in inguinal nodes. So possibility of blockage of lymph flow of lower limbs is high. And hence Lymphedema is likely cause.
2.
Hypoproteinemia and anemia also cause lower limb edema.
3. Decreased urine output due to kidney involvement.
4. Deep
venous thrombosis. This is rare complication of cervical cancer but can be the cause.
So ask her to
consult oncologist and discuss all these causes. Treatment of all these is different. So better to first diagnose herself and then start appropriate treatment.
Hope I have solved your query. Wishing good health to your sister. Thanks.