1. PET in Colorectal Cancer

2. Indications for FDG PET Rising marker, (-) CT/MRI Nonspecific findings on CT/MRI, recurrence or post treatment changes? Known metastases; evaluate extent or disease or identify other sites of recurrence Evaluate response to chemotherapy

3. LV 12/09/93 04/23/9608/22/96 PET-FDG SCAN IN RECTAL CA 191642

4. Coronal MSKCCAL361200

5. Case 1

6. Comparison of PET and CT N=40 pts. (93 biopsies) W CT =0.73+/-.06* W PET =0.97/-.02* *P<.001

7. Biopsy Correlated Finding

9. Diagnostic Imaging in Oncology Detection Differential Diagnosis Tumor biology relevant to therapy Staging Recurrence Response

10. PET in Colorectal Cancer PET accuracy between 88 - 92% > CT (75%) Among pt.s with suspected recurrence, SUV > 3.5 has a 90% probability of tumor, and a 10% prob of being a benign lesion Most common reasons for missing lesions is size (< 1 cm in diameter), location (peritoneum), and artifact (lesion near high count area) PET >> CT for Rx response in rectal Ca