The predictive role of interim Positron Emission Tomography on Hodgkin lymphoma treatment outcome is confirmed using the 5-point scale interpretation criteria

A retrospective international multicentre study was undertaken to assess (1) the prognostic role of interim Positron Emission Tomography performed during treatment with doxorubicin, bleomycin vinblastine and dacarbazine in patients with Hodgkin Lymphoma and (2) the reproducibility of the Deauville five-point scale for the interpretation of interim Positron Emission Tomography scans. 260 newly-diagnosed Hodgkin Lymphoma patients were enrolled. Fifty-three with early unfavorable and 207 with advanced-stage disease patients were treated with doxorubicin, bleomycin vinblastine and dacarbazine +/- involved-field or consolidation radiotherapy. Positron Emission Tomography scans were performed at baseline and after 2 cycles of chemotherapy. Treatment was not changed according to the results of the interim scan. An international panel of six expert reviewers independently reported the scans using the Deauville five-point scale, blinded to treatment outcome. Forty-five Positron Emission Tomography scans were scored as positive (17.3%) and 215 (82.7%) as negative. After a median follow up of 37.0 (2-110) months, 252 patients are alive and 8 have died. The 3-y progression-free survival was 83% for the study population, 28% for patients with interim positive scans and 95% for patients with interim negative Positron Emission Tomography scans respectively (p<.0001). The sensitivity, specificity, the negative and positive predictive values of interim Positron Emission Tomography for predicting treatment outcome were 0.73, 0.94, 0.94 and 0.73, respectively. Binary concordance amongst reviewers was good (Cohen kappa 0.69-0.84). In conclusion, the prognostic role and validity of the Deauville five-point scale for interpretation of interim Positron Emission Tomography scan have been confirmed by the present study.