16. FDG-PET in the Detection of Recurrence in Colorectal Cancer Based on Rising CEA Level. Experience in 72 Patients

Area of Science:

• Oncology
• Nuclear Medicine
• Radiology

Background:

• Elevated Carcinoembryonic Antigen (CEA) levels post-colorectal cancer resection indicate potential tumor recurrence.
• Conventional imaging modalities often lack the sensitivity to detect early recurrence in these patients.

Purpose of the Study:

• To evaluate the diagnostic utility of Positron Emission Tomography with 18F-Fluorodeoxiglucose (FDG-PET) in detecting colorectal cancer recurrence.
• To assess the impact of FDG-PET findings on therapeutic management decisions.

Main Methods:

• Seventy-two patients with elevated CEA and normal conventional imaging underwent FDG-PET.
• PET results were validated against pathological findings, radiological follow-up, and clinical follow-up.
• The influence of PET findings on treatment strategies was analyzed.

Main Results:

• FDG-PET detected lesions in 87.1% of patients.
• Metastatic sites included liver (44.1%), lymph nodes (27.5%), local recurrence (20.4%), and lung (8%).
• FDG-PET demonstrated high diagnostic accuracy (92.8%), sensitivity (94.4%), and specificity (83.3%), altering treatment in 94.1% of cases.

Conclusions:

• FDG-PET is a highly effective imaging tool for detecting colorectal cancer recurrence in patients with rising CEA levels and normal conventional imaging.
• Metabolic imaging with FDG-PET is a cost-effective diagnostic procedure that can guide treatment and avoid unnecessary invasive interventions.