Imaging scans may predict outcomes in patients with aggressive non-Hodgkin lymphoma (NHL).
That’s according to a recent study that evaluated how interim positron emission tomography (PET) scans performed after two cycles of standard NHL treatment—cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) plus rituximab (R-CHOP).
PET scans use a special dye that has radioactive tracers that help physicians see how well a patient’s organs and tissues are working.
However, the study also found that increasing treatment based on PET may not improve therapeutic outcomes among patients with aggressive non-Hodgkin lymphoma.
For the study, published in the Journal of Clinical Oncology, newly diagnosed patients received two cycles of CHOP—plus R-CHOP in CD20-positive lymphomas—followed by a PET scan that was evaluated using the ΔSUVmax method. PET-positive patients were randomly assigned to receive six additional cycles of R-CHOP or six blocks of an intensive Burkitt’s lymphoma protocol, according to the study authors. “PET-negative patients with CD20-positive lymphomas were randomly assigned or allocated to receive four additional cycles of R-CHOP or the same treatment with two additional doses of rituximab. The primary end point was event-free survival time as assessed by log-rank test,” the authors wrote.
“Interim PET can be used to identify patients with poor outcome after standard therapy,” says lead study author Ulrich Dührsen, Department of Hematology at the University Hospital Essen, part of the “Westdeutsches Tumorzentrum (WTZ),” one of only 12 Comprehensive Cancer Centers in Germany. “Changes in cytotoxic drug regimens, however, do not improve outcomes. Patients with a poor response to the first two cycles of standard therapy may be candidates for novel, non-chemotherapy-based treatment approaches, e.g. immunotherapy.”
The study found:
- Intensification of cytotoxic treatment does not improve outcome in patients with a poor response to the first two cycles of standard therapy.
- Increasing the cumulative dose of rituximab does not improve outcome of patients with aggressive B-cell lymphomas and a good response to the first 2 cycles of standard therapy.
- Increasing the cumulative dose of the CD20 antibody rituximab does not improve outcome in aggressive B-cell lymphomas. For patients with a good response to the first two cycles of R-CHOP, six doses of rituximab are sufficient.
“Outcome prediction by interim PET works well irrespective of type of aggressive lymphoma: diffuse large B-cell lymphoma, primary mediastinal B-cell lymphoma, follicular lymphoma grade 3, peripheral T-cell lymphomas,” says Dührsen. “The prognostic information provided by interim PET scanning is independent of other prognostic markers such as the International Prognostic Index. During the trial, the delta-SUVmax method was applied by local nuclear medicine physicians. On central review, there was very good reproducibility —98%. Therefore, the method is suited for everyday use.”
To predict outcome interim PET needs to be performed under strictly defined conditions and evaluated using the delta-SUVmax method, according to Dührsen.
“If these requirements are met, interim PET reliably identifies a group of patients with a very high likelihood of treatment failure,” he says. “Patients poorly responding to standard therapy do not benefit from treatment intensification. Novel, non-chemotherapy-based treatment approaches are required to improve their outcome. Interim PET may be used to identify patients who may benefit from such approaches (in clinical trials).”