Importance of positron emission tomography-computed tomography (PET-CT) examination in rectal cancer staging--initial clinical experience.

Aim: Accurate preoperative staging is essential in determining optimal therapeutic procedures and planning for individual patients. Advances in imaging technology have raised interest in the potential role of positron emission tomography-computed tomography (PET-CT) examination for staging of rectal cancer. The primary end point of the study was the correct classification of the tumor node-metastases (TNM) tumor stage using whole-body PET-CT examination.

Methods: This prospective study was performed from October 2011 to October 2012. Patients with histopathological diagnosis of rectal cancer after biopsy underwent PET-CT before surgical treatment and TNM staging. Twenty patients who fulfilled inclusion criteria were included in the study. All of the patients were operated and histopathology served as the standard of reference.

Results: There was no statistical significance in T staging comparing PET-CT and histopathological staging, according to the Monte Carlo simulation (p=.066). Also, there was no statistical significance between two methods in mesorectal fascia involvement analysis (p=1). There was statistical difference between PET-CT and histopathological staging. Sensitivity of the PET-CT for N staging was 86.7% and it was higher than for the histopathology. Two patients showed liver metastases.

Conclusion: Positron emission tomography-computed tomography examination could play an important role in the initial staging for the rectal cancer. Good patient selection for preoperative chemoradiotherapy ensures survival benefit. Avoidance of unnecessary therapeutic procedures allows an acceptable quality of patient's life.