Metabolic tumor parameters complement clinicopathological factors in prognosticating advanced stage Hodgkin Lymphoma

Objective(s): Advanced Hodgkin Lymphoma has a higher probability of relapse and recurrence. Classical clinicopathological parameters including the International Prognostic Score (IPS) have not been reliable in predicting prognosis or tailoring treatment.  Since FDG PET/CT is the standard of care in staging Hodgkin Lymphoma, this study attempted to evaluate the clinical utility of baseline metabolic tumor parameters in a cohort of advanced Hodgkin lymphoma (stage III and IV).Methods: Histology-proven advanced Hodgkin Patients presenting to our institute between ۲۰۱۲-۲۰۱۶ and treated with chemo-radiotherapy (ABVD / AEVD) were followed up till ۲۰۱۹. Quantitative PET/CT and clinicopathological parameters were used to estimate the Event Free Survival (EFS) in ۱۰۰ patients. Kaplan-Meier method with log-rank test was used to compare the survival times of prognostic factors.Results: At a median follow-up of ۴۸.۸۳ months (IQR:۳۳.۳۱-۶۳.۰۵ months), the five-year-EFS was ۸۱%. Of the ۱۰۰ patients, ۱۶ had relapsed (۱۶%) and none died at the last follow-up. On Univariate analysis, among non-PET parameters bulky disease (P=۰.۰۳) and B-symptoms (P=۰.۰۴) were significant while among PET/CT parameters SUVmax (p=۰.۰۰۱), SUVmean (P=۰.۰۰۲), WBMTV۲.۵ (P<۰.۰۰۱), WBMTV۴۱% (P<۰.۰۰۱), WBTLG۲.۵ (P<۰.۰۰۱) and WBTLG۴۱% (P <۰.۰۰۱) predicted poorer EFS.  ۵-year EFS for patients with low WBMTV۲.۵ [<۱۰۳۸.۳ cm۳] was ۸۹% and ۳۵% for patients with high WBMTV۲.۵ [≥۱۰۳۸.۳ cm۳] (p <۰.۰۰۱). In a multivariate model, only WBMTV۲.۵ (P=۰.۰۳) independently predicted poorer EFS.Conclusion: PET-based metabolic parameter (WBMTV۲.۵) was able to prognosticate and complement the classical clinical prognostic factors in advanced Hodgkin Lymphoma. This parameter could have a surrogate value for prognosticating advanced Hodgkin lymphoma. Better prognostication at baseline translates to tailored or risk-modified treatment and hence higher survival.

Keywords:

Advanced Hodgkin’s lymphoma , ۱۸F-FDG PET/ CT , metabolic tumor parameters , clinicopathological parameters , Event Free Survival