The clinical utility of PET/CT scan and tissue biopsy in the management and follow-up of paediatric Hodgkin lymphoma in South Africa

Abstract

Background: In low- to middle-income countries (LMICs) like South Africa, there is a need to understand the clinical practices surrounding diagnosis and surveillance of paediatric Hodgkin lymphoma (HL) to reduce the burden on health systems. Understanding the clinical utility of PET/CT scans may decrease repeated tissue biopsies during disease surveillance.

Methods: This is a retrospective cohort study of patients aged less than 18 years treated for HL at Chris Hani Baragwanath Academic Hospital from 1 January 2009 to 31 December 2018.

Results: Fifty-four patients were included in the study; male-to-female ratio was 5:1 with a mean age of 9 years. Seventy per cent of patients (n = 38) received a PET/CT and tissue biopsy during their initial diagnostic workup, whereas 20.4% (n = 11) of patients received a PET/CT and tissue biopsy during surveillance. Tissue biopsy and PET/CT showed slight agreement (κ = 0.14) in diagnosing relapsed disease during surveillance. The false negative rate for tissue biopsy during surveillance was 42.9%. Surveillance PET/CT showed a positive predictive value (PPV) of 66.7% and negative predictive value (NPV) of 100% when compared to tissue biopsy.

Conclusion: This study is the first cohort to explore the clinical utility of PET/CT scans and tissue biopsies in a lowresourced setting. Our findings showed slight agreement between the modalities in diagnosing relapsed disease during surveillance. A portion of this discordance can be attributed to false negative tissue biopsy results. While the sample is limited, our findings are consistent with the high NPV of PET/CT scans of > 95% as is reported in the literature.