Patterns of relapse and long-term outcome in patients treated with a curative intent for advanced Hodgkin lymphoma

Consolidation radiotherapy for advanced Hodgkin lymphoma (AHL) is controversial. Precise knowledge of the most likely relapse location is crucial for radiotherapy planning. We performed detailed patterns of relapse analyses and evaluated if initial bulky disease, initial 18F-fluoro-deoxy-glucose (FDG)-avidity and/or a residual mass on computed tomography (CT)-scan after chemotherapy are sites with a high risk of relapse. This information could provide guidance for optimal use of radiotherapy in AHL.

We included 133 patients treated with curatively intended chemotherapy for AHL. 23 patients received consolidation radiotherapy. For relapsed patients, imaging from diagnosis, response evaluation, relapse, and any radiotherapy planning, were retrieved and co-registered to determine the exact site(s) of relapse relative to initial site(s), residual mass(es) and to any irradiated volumes. Size and FDG-avidity of initial sites with later relapse, and residual CT-abnormalities after chemotherapy in these sites were registered. Survival analyses were done using the Kaplan-Meier method.

Nine (6.8%) patients relapsed, eight in initially involved sites. One relapse was in an initially irradiated site (as well as other sites). Initial bulky disease, high initial FDG-uptake, and/or residual masses on CT-scan after chemotherapy did not predict sites with a high risk of relapse. Overall survival was 79.6% (95% CI, 72.7-86.5%) and 70.6% (95% CI, 62.4-78.8%) at 5 and 10 years, respectively. Time to progression analysis showed 91.8% (95% CI, 86.9-96.7%) and 90.7% (95% CI, 85.4-96.0%) without progression at 5 and 10 years, respectively.

Current treatment strategies for AHL provide excellent disease control. Neither initial bulk, high initial FDG-uptake, nor a residual CT-abnormality post-chemotherapy seem to indicate sites with a high risk of relapse.