A study on the use of positron emission computed tomography analysis in recurrent colorectal cancer

Introduction: Colorectal cancer is a common neoplasm in Europe and the United States. Even after apparently curative resection, recurrences occur in one-third of patients, usually within the first 2 to 3 years after the surgery.

Aim: Investigation the role of 18-fluorodeoxyglucose positron emission tomography/computed tomography (18-FDG PET/CT) in detection of recurrent colorectal cancer.

Material and methods: A retrospective analysis of 75 tumours from 59 patients with recurrent colorectal carcinoma was made.

Results: Detecting recurrent colorectal cancer FDG PET/CT revealed 92% sensitivity. PET/CT correctly identified 69 of 75 tumours. Negative PET/CT results of the examination depend on necrotic changes occurring in them (p < 0.01). SUV_max in tumours without necrotic changes was indeed statistically higher than in tumours with necrotic changes (p < 0.01). SUV_max in tumours located in the liver is indeed statistically higher than in tumours located in lungs (p < 0.05). A correlation between SUV_max of the tumour and age of the patients and the maximum dimension of the tumour was not found

(p < 0.05).

Conclusions: This study demonstrates that PET/CT is of high sensitivity. We conclude that FDG PET/CT is a powerful diagnostic imaging method, which has ability to improve accurate detection of recurrent colorectal cancer. The limitations of PET/CT are related to cellularity of the tumours. It is necessary to continue the study on correlation between SUV and molecular factors of tumours.