Comparison of Interim PET Response to Second-Line Versus First-Line Treatment in Classic Hodgkin Lymphoma: Contribution to the Development of Response Criteria for Relapsed or Progressive Disease.

Abstract

In first-line treatment of Hodgkin lymphoma (HL), Deauville scores 1-3 define complete metabolic remission. Interim ¹⁸F-FDG PET is also used for relapse-treatment adaptation; however, PET response criteria are not validated for relapse treatment. <b>Methods:</b> We performed a pairwise comparative analysis of early response to first- and second-line treatments in 127 patients with classic HL who experienced relapse. The patients participated in the prospective, multicenter EuroNet-PHL-C1 study. Residual uptake was measured retrospectively using the qPET method, a validated semiautomatic quantitative extension of the Deauville score. Empiric cumulative distribution functions of the qPET values were used to systematically analyze the response to first- and second-line treatments. <b>Results:</b> Individual patients responded variably to first- and second-line treatments. However, the empiric cumulative distribution functions of the qPET values from all patients were nearly superimposable. <b>Conclusion:</b> The findings support that first- and second-line treatments in HL do not require different response criteria.