Limiting surveillance imaging for patients with lymphoma in remission: a mixed methods study leading to a Choosing Wisely recommendation

Background: Under the 'Choosing Wisely' (CW) framework, professional organisations internationally have advocated limiting imaging for asymptomatic patients following curative cancer therapy, based on limited value and high cost. F18-fluorodeoxyglucose (FDG) positron emission tomography-CT (PET/CT) was widely adopted locally for surveillance lymphoma imaging after 2004.

Objectives: Prior to ratification of a local CW recommendation to limit surveillance imaging in lymphoma, we aimed to assess: (A) performance characteristics of surveillance FDG-PET/CT; (B) rates, clinical consequences and costs of false positives (FP); and (C) patients and professionals' attitudes towards overuse.

Methods: Mixed methods (quantitative and qualitative) study. We analysed surveillance FDG-PET/CT results of two patient cohorts (n1=215 Hodgkin lymphoma and non-Hodgkin lymphoma; n2=203 Hodgkin lymphoma only). FPs were defined by negative biopsy or clinical follow-up. We held focus group discussions and in-depth interviews eliciting attitudes of 26 patients and 11 clinicians, respectively.

Results: FPs were observed in 25.1% (95% CI 20.5 to 30.5) per scan-cohort 1, and 41.7% (95% CI 37.9 to 45.6) per patient-cohort 2, engendering frequent additional testing. Specific characteristics and location of findings altered the FP rate. The estimated cost per relapse detected was $50 000 (cohort 2). Patients sought reassurance via surveillance imaging, which they considered highly accurate, yet stressful. Aware of radiation risks, they were largely unconcerned about consequences of FPs. Confidence in the treating physicians was an important factor in patients' acceptance of forgoing imaging. Clinicians, frequently under patient pressure to order imaging, generally believed that it did not affect prognosis (with important exceptions), welcomed professional guidelines, but rejected regulatory restrictions on its use.

Conclusion: Acceptance of CW recommendations to limit overuse may be enhanced by quantitative data on consequences and costs of surveillance imaging, supplemented by qualitative data on patient and physician attitudes.