PET in Colorectal Cancer
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
LV 12/09/93 04/23/9608/22/96 PET-FDG SCAN IN RECTAL CA
Coronal MSKCCAL361200
Case 1
Comparison of PET and CT N=40 pts. (93 biopsies) W CT =0.73+/-.06* W PET =0.97/-.02* *P<.001
Biopsy Correlated Finding
Diagnostic Imaging in Oncology Detection Differential Diagnosis Tumor biology relevant to therapy Staging Recurrence Response
PET in Colorectal Cancer PET accuracy between % > 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