Purpose: Determine the utility of fusion positron emission tomography/computed tomography (PET/CT) in mapping surgical procedures for suspicious colorectal masses in the era of minimally invasive surgery—laparoscopy/robotics where haptic feedback is absent.
Background: The National Comprehensive Cancer Network (NCCN) guidelines recommend using CT of the chest, abdomen, and pelvis for colorectal cancer staging. This is largely because PET/CT is not widely available, thus limiting access. Colonoscopy is used to locate/diagnose colorectal masses. Gastroenterologists often “guestimate” the location of the lesion either by anatomical landmarks or by measurement on the colonoscope itself. These are often inaccurate. It is the standard of care to ink the location of the lesion as well. This is not always done or easy to identify. It is often necessary to perform an intraoperative colonoscopy to locate the lesion in question and then make incisions or dock the robot accordingly.
Methods: Retrospective data from a colorectal surgeon were reviewed. Surgeries performed at the Raymond G. Murphy VAMC from March 2012 to June 2015 were included. Data were reviewed for these patients to evaluate for the efficacy of fusion PET/CT studies in identifying the lesion in question regardless of benign or cancerous lesion, mapping of the planned procedure, and how it affected planned treatment algorithms.
Results: Fifty patients were referred for evaluation and treatment of a suspicious colorectal mass, and 45 patients underwent PET/CT for staging. The lesion was not PET avid in 9 patients, and 36 patients had positive findings on the study. Thirty-two of those patients had findings fairly consistent with the colonoscopy site identifiers. In 5 patients, the PET/ CT results changed the planned surgery or delayed surgery for neoadjuvant chemoradiotherapy. The nonvisualized patients were either mucinous or no residual tumor remained.
Conclusions: Although PET/CT is not the recommended staging study by NCCN guidelines for colorectal cancers, it is readily available at our VAMC and proves useful in differentiating scar from tumor when compared with CT alone. Our experience showed that PET/CT is often positive in suspicious colorectal masses, helps to map the surgery, and acts as a baseline for ongoing surveillance. It ultimately can change the entire treatment algorithm for our individual patients.
