Low-dose chest CT for surveillance of recurrent or 2nd primary lung cancer in post-operative stage I and II lung cancer patients
There is no established method for post-operative surveillance of patients after resection of lung cancer. We conducted an observational study using low radiation-dose chest CT (LDCT) as a surveillance tool for recurrent or new primary lung cancer.
From 1998 to present, patients who underwent resection of stage I or II non-small cell lung cancer (NSLC) were followed with a LDCT one year post-operatively. Suspicious non-calcified nodules that were found were then evaluated depending upon size. Nodules <5mm were followed every 6 months. Nodules between 5-9mm were followed 4-6 months later. Nodules 10mm and greater were evaluated with either trans-thoracic needle biopsy, bronchoscopy, PET scan, or thoracotomy. Any nodule demonstrating interval size increase was biopsied.
Consent was obtained from 25 patients with resected stage I and II NSLC. The average time to the first LDCT was 12 months post-operatively. At 1 year follow-up, 18 nodules less than 5mm in size, 5 nodules between 5 and 9mm, and 7 nodules greater than 10mm were found. Of the nodules that were <9mm, all were either stable or decreased in size on follow-up CT scans. One of the 7 nodules that were greater than 10mm was observed with repeat LDCT as it was retrospectively seen on a preoperative CT scan. This nodule, after 2 subsequent LDCT’s, was found to be a 2nd primary stage I adenocarcinoma that was resected. One nodule grew in size on follow-up CT scan, was biopsied, and found to be negative for malignancy. The rest of the nodules >10mm nodules were either stable or regressed.CONCLUSIONS: LDCT detected one new primary cancer that was resectable. In routine surveillance, many small nodules are found that are not of any significance.
LDCT can be used as a post-operative surveillance tool. More data is necessary to draw any other conclusions.
M.R. Patel, None.