Browse the corpus
Walk the evidence base by book and chapter — the raw source passages that ground Ask, Differential, and the rest.
1 passage
The routine use of PET is not recommended for the diagnosis or staging of clinical stage I-III colorectal cancers. PET is recommended for determining management and prognosis if conventional imaging is equivocal for the presence of metastatic disease. One systematic review of two primary studies and one additional primary study summarised that PET has good sensitivity to detect primary tumours greater than 2 cm, but not smaller tumours, with variable specificity. Recurrence and restaging: PET is not recommended for routine surveillance in patients with colorectal cancer treated with curative surgery at high risk for recurrence. PET is recommended to determine the site of recurrence in the setting of rising carcinoembryonic antigen when a conventional workup fails to unequivocally identify metastatic disease. In the evaluation of patients potentially eligible for the curative resection of colorectal cancer liver metastasis, a diagnostic CT is necessary in addition to PET/CT to provide information on hepatic vasculature and anatomy. The sensitivity of PET for detecting metastases decreases following neoadjuvant chemotherapy in patients with colorectal cancer liver metastasis, and PET is less sensitive than CT for detecting metastases following neoadjuvant chemotherapy.