Page 190 - 18F-FDG PET as biomarker in aggressive lymphoma; technical and clinical validation

Chapter 7
(nine patients with unknown BCL2 and BCL6 rearrangement not included).
Table 2. Response rates on interim and EOT PET-CT scan.
EOT CMR PMR PMD Unknown$ Total
Interim
CMR n PMR n PMD n Total n
Nnnnn 45 0 11 1 57 10 4 9 0 23 0 1 1 0 2 55 5 21 1 82
Response rates on interim and EOT PET-CT scan. Correlation of interim and end of treatment (EOT) response rates by centrally reviewed positron emission tomography (PET)- computed tomography (CT) scan.
$One patient was in complete metabolic response (CMR) at interim scan but went off protocol due to toxicity without an EOT scan. PMR: partial metabolic response, PMD: progressive metabolic disease.
Secondary endpoints: survival analyses
With a median follow-up of 25.4 months (IQR 18.3- 30.3), 1-year OS was 85% (95% CI: 76-91), DFS 77% (95% CI: 65-85) and EFS 66% (95% CI: 54-75). 2-year estimates for OS, DFS, EFS were and 73% (95% CI: 62-82), 75% (95% CI: 63-84) and 63% (95% CI: 52-73) respectively (Figure 2A-C). Baseline patient characteristics (BM localization, WHO performance status, stage, B symptoms, IPI, number of extranodal sites and age) were not significantly predictive for prolonged OS in a univariate analysis at the 5% significance level. Univariate regression analyses indicated that SH and DH/TH patients had comparable EFS and DFS, however DH/TH patients had a tendency for a higher risk of death compared to SH patients (Hazard ratio [HR]4.18, P=0.055; 95% CI: 0.97-18.02) (Online Supplementary Figure S1A-C). Separate analyses of DH MYC/BCL2 and DH MYC/BCL6 and TH in comparison to SH revealed no significant differences in OS (Online Supplementary Figure S2A-B). In univariate analyses with response as time dependent covariate we found that patients who had achieved CMR at EOT PET experienced a reduced risk of death compared to patients who had not achieved CMR (HR 0.1, 95% CI: 0.03–0.33, P<0.001), (Figure 3). EOT PET-CT predicted relapse within 12 months, with a positive predictive value (PPV) of 81% and a negative predictive value (NPV) of 93% (Online Supplementary Table S3A). In total, 29 patients showed progressive disease (11 without achieving CMR, 18 after achieving CMR [(at interim or EOT PET-CT)] including one patient with a CNS relapse.
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