Outcome of Hodgkin Lymphoma Patients with a Posttreatment ¹⁸F-Fluoro-2-Deoxy-d-Glucose Positron Emission Tomography (FDG-PET)-Negative Residual Mass: Systematic Review and Meta-analysis

To systematically review and meta-analyze the outcome of Hodgkin lymphoma patients with a posttreatment ¹⁸F-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET)-negative residual mass. A systematic PubMed/MEDLINE database search was performed. The methodological quality of included studies was assessed. The number of patients with a posttreatment non-FDG-avid residual mass and the number of these patients who developed disease relapse during follow-up were extracted from each included study. Heterogeneity in disease relapse proportions across individual studies was assessed using the I² test, with heterogeneity defined as I² > 50%. Using a Freeman-Tukey transformation, the disease relapse proportions from each individual study were then meta-analyzed with either a fixed-effects model (if I² ≤ 50 %) or a random-effects model (if I² > 50 %). A total of 5 studies comprising a total of 727 Hodgkin lymphoma patients with an FDG-PET-negative residual mass after first-line therapy were included. The overall quality of included studies was moderate. The proportion of patients with a posttreatment non-FDG-avid residual mass who experienced disease relapse during follow-up ranged between 0% and 13.8%. There was heterogeneity in disease relapse proportions across individual studies (I² = 61.4%). Pooled disease relapse proportion (random effects) was 6.8% (95% confidence interval: 2.6%-12.5%). The disease relapse rate in Hodgkin lymphoma patients with a FDG-PET-negative residual mass after first-line therapy is approximately 6.8%. Considering the existing literature, the presence of a non-FDG-avid residual mass has not been proven yet to be associated with a worse outcome than a posttreatment FDG-PET-based complete remission status without a residual mass.