Duhrsen U, et al. - Whether positron emission tomography (PET) can guide therapy in patients with aggressive non-Hodgkin lymphomas who are treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), was investigated. Interim PET enabled survival prediction in patients with aggressive lymphomas treated with CHOP—plus rituximab (R-CHOP). No outcome improvement was seen with PET-based treatment intensification.

Methods

• Researchers administered two cycles of CHOP—plus rituximab (R-CHOP) in newly diagnosed patients with CD20-positive lymphomas—followed by a PET scan that was assessed using the ΔSUV_max method.
• Random assignment of PET-positive patients to receive six additional cycles of R-CHOP or six blocks of an intensive Burkitt’s lymphoma protocol was done.
• In a random manner, four additional cycles of R-CHOP or the same treatment with two additional doses rituximab was administered to PET-negative patients with CD20-positive lymphomas.
• Event-free survival time as assessed by log-rank test was the primary end point.

Results

• In 108 (12.5%), interim PET was positive and it was negative in 754 (87.5%) of 862 patients treated, with statistically significant differences observed in event-free survival and overall survival.
• Data showed 52 of PET-positive patients were randomly assigned to R-CHOP and 56 to the Burkitt protocol, with 2-year event-free survival rates of 42.0% (95% CI, 28.2% to 55.2%) and 31.6% (95% CI, 19.3% to 44.6%), respectively (hazard ratio, 1.501 [95% CI, 0.896 to 2.514]; P=.1229).
• Significantly more toxicity was seen in those who received the Burkitt protocol.
• A total of 255 of 754 PET-negative patients underwent random assignment (129 to R-CHOP and 126 to R-CHOP with additional rituximab).
• Researchers found that event-free survival rates were 76.4% (95% CI, 68.0% to 82.8%) and 73.5% (95% CI, 64.8% to 80.4%), respectively (hazard ratio, 1.048 [95% CI, 0.684 to 1.606]; P=.8305).
• PET enabled outcome prediction independent of the International Prognostic Index.
• Similarity was noticed in the results in diffuse large B-cell lymphoma vs those in the total group.