The goal of this clinical trial is to learn if adding a radiation boost (intra-lesional boost) works to treat patients with large-sized cervical cancer. It will also learn about the safety of this treatment. The main questions it aims to answer are:
* Does the extra radiation boost effectively reduce the tumor size before the internal radiation (brachytherapy) treatment begins?
* What medical problems (side effects) do participants have when receiving this treatment?
Researchers will give this intra-lesional boost to all participants during their standard radiation therapy to see if it helps shrink the tumor more than usual.
Participants will:
* Receive radiation therapy to the pelvis with a targeted boost to the tumor for about 5 to 6 weeks
* Visit the clinic daily for radiation treatment and regularly for checkups Have an MRI scan during the 4th or 5th week of treatment to measure the tumor size
* Receive internal radiation therapy (brachytherapy) after finishing the external radiation
* Visit the clinic for follow-up checkups and tests for up to 2 years