Brain metastases following radical surgical treatment of non-small cell lung cancer: is preoperative brain imaging important?

ABSTRACT

OBJECTIVES: There is a lack of good quality evidence or a clear consensus of opinion internationally regarding who should receive preoperative imaging of the brain prior to radical treatment for non-small cell lung cancer (NSCLC). We aimed to establish the proportion of patients who developed brain metastases following curative surgery and to estimate how many could have been detected by preoperative magnetic resonance imaging (MR). METHODS: We performed a retrospective analysis of 646 patients who underwent surgery for lung cancer with curative intent at a regional thoracic surgical centre in the United Kingdom. We identified those who developed brain metastases in the postoperative period and, by using volume doubling times, estimated the size of the metastasis at the time of surgery. We then determined the proportion of metastases that would have been seen on preoperative MR brain at detection thresholds of 2 and 5mm diameter. RESULTS: There was a 6.3% incidence of postoperative brain metastases, with the majority occurring within 12 months of surgery. Those who developed metastases were more likely to have adenocarcinoma and the majority had early stage malignancy (73% stage I or stage II). We estimate that 71% of those who developed cerebral metastases might have been detected had they undergone MR brain as part of their staging (4.4% of all patients). CONCLUSION: Based on our findings we suggest that, in addition to standard staging investigations, patients have brain imaging (MR or equivalent) prior to curative surgery in NSCLC regardless of preoperative stage.