How is cryosurgery used in oncology?

Cryosurgery in oncology uses liquid nitrogen to freeze pre-cancerous and cancerous cells. Cryosurgery is often used to prevent the development of cancers on the penis, skin, and cervix. It may be used to treat liver and prostate cancer. Oncologists use CT scan or ultrasound imaging during the procedure so that they can zero in on abnormal cells and refrain from killing healthy ones.