Optimal disease surveillance strategies in non-Hodgkin lymphoma

Given the paucity of randomized controlled trial data, defining the ideal strategy for surveillance imaging in patients with non-Hodgkin lymphoma (NHL) has become increasingly challenging. The routine use of frequent surveillance scans has been a common component of patient care. Emerging data from prospective and retrospective observational studies and modeling approaches have highlighted the performance characteristics of imaging modalities and the challenges with this form of secondary screening. The majority of patients with relapsed lymphoma have clinical signs or symptoms that prompt further evaluation, and only a small proportion of patients experience relapse detected on a routine scan while being otherwise asymptomatic. Surveillance imaging is costly, may expose patients to minimal risks of mortality due to radiation-related secondary malignancies, and can lead to false-positive findings, leading to unnecessary biopsies. In addition, no prospective study has demonstrated a significant improvement in overall survival for those patients whose disease is discovered on a routine scan versus those who present with clinical symptoms. In this chapter, we examine the baseline risks of relapse for various NHL subtypes that provide the context for surveillance, review the data on imaging modalities, and establish a framework for discussing optimal surveillance strategies with individual patients. Patients should be counseled on the risks and benefits of routine surveillance imaging and decisions regarding surveillance should be made on an individual basis using patient-specific risk factors, response to induction therapy, and patient preferences with a bias toward using surveillance imaging in the 2 years after treatment only in those NHL patients with the greatest likelihood of benefit.