normal  medium  large

Tandem and ovoid is less frequently performed as an HDR treatment, but consists of the tandem and the ovoid. The tandem is a small metal tube that is placed inside the patient's uterus and an ovoid is a similar metal tube with a circular shape for treatment of the cervix. During treatment the radioactive source will pass through both the tandem and the ovoid at different times to ensure that the entire region is properly treated.