Evaluation of the Effects of R-CHOP Chemotherapy on Brain Glucose Metabolism in Patients with Diffuse Large B Cell Lymphoma: A Baseline, Interim, and End-of-Treatment PET/CT Study

Background: To investigate the effect of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy on brain glucose metabolism in patients with diffuse large B cell lymphoma (DLBCL). Methods: Seventy-two patients with newly diagnosed DLBCL underwent FDG PET/CT brain and whole-body scans at baseline (PET0), in the interim of chemotherapy (PET2), and at the end (PET6) of chemotherapy. All three brain scans of each patient were analyzed using statistical parametric mapping software. Results: Compared with the PET0 scan, the PET2 and PET6 scans revealed a significantly higher glucose metabolism throughout the whole brain, with the PET6 scan revealing a higher metabolism than the PET2 scan. Patients with a complete response (CR) displayed decreased glucose metabolism in the lingual gyrus and increased glucose metabolism in the pons after chemotherapy compared with the findings in patients with partial responses or progressive disease. Conclusions: Brain glucose metabolism was affected by R-CHOP treatment throughout the entire chemotherapy protocol.