Hi.
What is the stage of your colorectal cancer?
From what you posted, you are responding to your treatment as evidenced by disappearance of the metastasis and involved lymph node seen on PET scan. You should continue with your adjuvant chemotherapy using 5-fluorouracil.
Anatomically, the rectum is different from the colon. The rectum can be divided into 3 segments: lower rectum, mid rectum, upper rectum. A portion of the upper rectum, as well as the other segments, do not have a peritoneal cover. This lack of peritoneal cover makes the part at higher risk of local recurrence after surgery of cancer. Radiotherapy is added to chemotherapy to reduce the risk of local recurrence.
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