Page 165 - 18F-FDG PET as biomarker in aggressive lymphoma; technical and clinical validation

Rituximab intensification during R-CHOP in DLBCL
IPI score; Fig 2D); the 5-year OS rates were 77% (95% CI, 71% to 81%) and 69% (95% CI, 63% to 74%), respectively.
A total of 210 patients died, 96 in the R-CHOP-14 arm (lymphoma related, n = 41; treatment related, n = 9; intercurrent death, n = 8; secondary malignancies, n = 11; other reasons, n = 15; and unknown causes, n = 12) and 114 in the RR-CHOP-14 arm (lymphoma related, n = 56; treatment related, n = 10; intercurrent death, n = 10; secondary malignancies, n = 11; other reasons, n = 11; and unknown causes, n = 16).
Planned subgroup analyses showed that the impact of RR-CHOP-14 versus R-CHOP-14 on FFS, PFS, DFS, and OS was not different between subgroups of age (18-65 v 66-80 years), sex (male v female), or age-adjusted IPI score (low v low-intermediate v high-intermediate v high). Post hoc analyses showed similar results for subgroups according to DLBCL phenotype. Figure 3 and Appendix Figures A1 and A2 (online only) show the Kaplan-Meier PFS curves for these subgroups.
Results of the multivariable analyses of individual prognostic factors for the survival end points FFS, PFS, and OS are listed in Table 2 (and for DFS in Appendix Table A2, online only). The HRs for both treatment arms were similar compared with those in the analyses with adjustment for only age group and age-adjusted IPI score, confirming that survival was not improved in either subgroup in the RR-CHOP-14 arm. The only statistically significant prognostic factor was age 66 to 80 years.
PET-CT Assessment
PET-CT scans were visually assessed using the 5-point DS; DSs 1 to 3 were regarded as negative and DSs 4 to 5 as positive. A total of 496 end-of-treatment (EOT) PET scans were centrally reviewed. In 417 patients (84%), the EOT PET- CT scans were negative, and 79 patients (16%) had positive EOT PET scans. The estimated 2-year PFS rate in patients with EOT PET–positive scans was 46% (95% CI, 36% to 57%) versus 88% (95% CI, 85% to 92%) in those with EOT PET–negative scans (P < .001). The 2-year OS rate was 58% (95% CI, 47% to 69%) for patients with EOT PET–positive scans and 94% (95% CI, 91% to 96%) for those with EOT PET–negative scans. Corresponding positive and negative
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