Monitoring clinical outcomes in aggressive B-cell lymphoma: From imaging studies to circulating tumor DNA

Recent guidelines have de-emphasized the role of routine surveillance computed tomography (CT) scans for diffuse large B-cell lymphoma (DLBCL) patients who achieve a complete response to front-line therapy. This shift in practice recommendations was prompted by retrospective studies that failed to demonstrate clear clinical utility for surveillance CT in unselected DLBCL patients. Controversy remains, however, over the role of routine surveillance CT in the highest risk patients for treatment failure who would remain candidates for aggressive salvage therapies. Novel high-throughput sequencing methods can non-invasively monitor tumor-specific DNA in the blood and offers clear advantages designed to overcome fundamental limitations of CT scans. This review will discuss the current controversies surrounding monitoring clinical outcomes in aggressive B-cell lymphomas, with a specific emphasis on DLBCL. Fundamental limitations of imaging scans will be addressed and the potential of monitoring circulating tumor DNA as an adjunct or replacement for CT scans will be discussed.