18F-FDG PET changes management and improves prognostic stratification in patients with colorectal cancer: results of a prospective, multi-centre study

Abstract

4025 Background: The aims were to: 1) examine the impact of PET in changing management in patients with proven or suspected recurrence of colorectal cancer and, 2) assess the impact of management change on disease free survival. Methods: Symptomatic patients (Group A) with a residual structural lesion suspicious for recurrent tumour, or patients (Group B) with pulmonary or hepatic metastases, which were potentially resectable as determined by conventional imaging, underwent PET scans. Pre- and post-PET management plans were documented blinded to PET results. Patients were followed for 12 months to determine actual management and to assess clinical outcomes. Results: A total of 191 patients (118M:73F, mean age 66 yrs) were recruited. PET detected additional sites of disease in 48.4% of Group A and 43.9% of Group B patients. Importantly, a change in planned management was documented in 65.6% of Group A and 49.0% of Group B patients. Follow-up confirmed implementation of management plans in 96% of patients. Analysis of follow-up data to 12 months post- PET showed that in Group A progressive disease was identified in 60.5% of patients with additional lesions detected on PET compared with conventional imaging, and 36.2% patients with no additional lesions detected by PET (p=0.0364); in Group B progressive disease was identified in 65.9% of patients with additional lesions detected on PET and 39.2% patients with no additional lesions detected by PET (p=0.0198). Patient follow-up also showed that PET provided valuable prognostic information in patients stratified into curative/palliative intent groups. Conclusions: These data unequivocally demonstrate the significant impact of PET on management and outcomes in patients with suspected recurrent colorectal cancer. No significant financial relationships to disclose.