1. Rectal Cancer ContouringSpeakers : Tz-yu Lin & Shr-Uen Lin Advisor : Dr. Jason Cheng Date : 2013/12/18

2. 54 y/o, male, Constipation and bloody stool for one month Digital rectal exam: cauliflower mass at posterior rectum wall, 3 cm from anal verge. Biopsy: adenocarcinoma. MRI Pelvis: Abnormal thickening and enhancing wall Increased fatty stranding in the perirectal space. Multiple enlarged lymph node in the perirectal space. No evidence of para-aortic lymphadenopathy Whole Body PET: intense hypermetabolic lesion at rectum Mild to moderate hypermetabolic spots at right perirectal and bilateral external iliac nodes Rectal adenocarcinoma cT3N1M0 3. DOI: 10.1056/NEJMoa040694 4. Mesorectal lymph nodes (MLN) : 46% of all patients 87% of patients with positive lymph nodes Risks for Lymph node involvement in N+ patients: Mesorectal : 87% Lateral : 27% External iliac : 9% Inguinal : 1%Posterior pelvic subsite (PPS) recurrence : 22% of all patients Inferior pelvic subsite (IPS) recurrence: 4% of all patients 8% in tumors < 6 cm from anal verge 5. Rectal Cancer Radiotherapy Contouring Guideline for clinical target volumes (CTV) for neoadjuvant chemoradiotherapy in locally advanced rectal cancer: gross tumor, peri-rectal, pre-sacral, internal iliac and external iliac. NTUH practice: GTV: main tumor mass + involved lymph nodes CTV: GTV with 15 mm expansion Distal 20 mm margin to GTV for CTV Vessels with 7 mm expansion Contour CTV to include mesorectum and pre-sacrum Avoid bone and small bowelInt J Radiat Oncol Biol Phys. 2009 Jul 1;74(3):824-30. doi: 10.1016/j.ijrobp.2008.08.070. 6. Lowest boundary of GTV 7. Lymph node metastasis 8. Lymph node metastasis 9. Lower boundary of CTV 10. Lymph node metastasis, bifurcation of iliacs 11. Common iliacs 12. Summary Pre-op CCRT is the standard treatment for locally advanced rectal cancer Contouring guideline GTV: main tumor mass + involved lymph nodes CTV: GTV with 15 mm expansion Distal 20 mm margin to GTV for CTV Vessels with 7 mm expansion Contour CTV to include mesorectum and pre-sacrum Avoid bone and small bowel 13. THE END THANKS FOR YOUR ATTENTION!!! 14. Abdominoperineal resection (APR)sphincter preserving surgeryTotal mesorectal excision