Image-Guided Radiotherapy and Chemotherapy in Gynaecological Cancer

Varying definitions of rectum in RT studies and practice

• Superior

• Inferior

– Rectosigmoid junction – 12 cm from the anus – Top of acetabula – At the level of  S3 – Inferior level of sacroiliac joints – 1 cm above the PTV

– Anal verge – Ano-rectal junction – 1 cm below PTV – Ischial tuberosities – Ischial tuberosities + 2 cm

• Circumferential

– Rectum + contents – Rectal wall