Background: In the United States, patients with clinical stage II or III rectal cancer typically receive neoadjuvant chemoradiation therapy (chemo/XRT) over a 5-6 week period followed by a 6-10 week break prior to proctectomy. In the current study, we evaluate the utilization of restaging studies performed and detection of disease progression during this window.
Methods: A retrospective review of patients with clinical stage II/III rectal cancer was performed. Medical records were analyzed to collect clinicopathologic data and the performance and results of preoperative, early postoperative, and first surveillance CT and/or PET/CT in patients completing long course neoadjuvant chemo/XRT and undergoing proctectomy.
Results: Between 2005 and 2017, 176 patients with clinical stage II or III rectal adenocarcinoma completed neoadjuvant chemo/XRT and underwent proctectomy. Preoperative restaging with CT CAP and/or CT/PET was performed in 72 (40.9%) patients with no detection of disease progression. Of the 104 patients without preoperative restaging, 1 had intraoperative detection of liver metastases and 31 had early postoperative reimaging (within 30 days of proctectomy) of which 2 had detection of new pulmonary metastases. Among 72 patients with no preoperative or early postoperative reimaging, first surveillance imaging was available in 47 and detected new metastases in 8 (17%).
Discussion: In patients with clinical stage II/III rectal cancer who undergo long course neoadjuvant chemo/XRT, perioperative reimaging with CT CAP and/or PET/CT detects new metastases in a small percentage of patients. A multi-institutional, prospective analysis using standardized staging protocols is warranted to better determine the value of preoperative restaging in these patients.
Keywords: neoadjuvant Chemoradiation; rectal cancer; staging.