The role of 18F-FDG PET/CT in patients with diffuse large B-cell lymphoma after radioimmunotherapy using 131I-rituximab as consolidation therapy

PLoS One. 2022 Sep 26;17(9):e0273839. doi: 10.1371/journal.pone.0273839. eCollection 2022.

Abstract

Purpose: To evaluate the prognostic value of pretreatment 18F-FDG PET/CT after consolidation therapy of 131I-rituximab in patients with diffuse large B-cell lymphoma (DLBCL) who had acquired complete remission after receiving chemotherapy.

Methods: Patients who were diagnosed with DLBCL via histologic confirmation were retrospectively reviewed. All patients had achieved complete remission after 6 to 8 cycles of R-CHOP (rituximab, cyclophosphamide, vincristine, doxorubicin, and prednisolone) chemotherapy after which they underwent consolidation treatment with 131I-rituximab. 18F-FDG PET/CT scans were performed before R-CHOP for initial staging. The largest diameter of tumor, maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were obtained from pretreatment 18F-FDG PET/CT scans. Receiver-operating characteristic curves analysis was introduced for assessing the optimal criteria. Kaplan-Meier curve survival analysis was performed to evaluate both relapse free survival (RFS) and overall survival (OS).

Results: A total of 15 patients (12 males and 3 females) with a mean age of 56 (range, 30-73) years were enrolled. The median follow-up period of these patients was 73 months (range, 11-108 months). Four (27%) patients relapsed. Of them, three died during follow-up. Median values of the largest tumor size, highest SUVmax, MTV, and TLG were 5.3 cm (range, 2.0-16.4 cm), 20.2 (range, 11.1-67.4), 231.51 (range, 15-38.34), and 1277.95 (range, 238.37-10341.04), respectively. Patients with SUVmax less than or equal to 16.9 showed significantly worse RFS than patients with SUVmax greater than 16.9 (5-year RFS rate: 60% vs. 100%, p = 0.008). Patients with SUVmax less than or equal to 16.9 showed significantly worse OS than patients with SUVmax greater than 16.9 (5-year OS rate: 80% vs. 100% p = 0.042).

Conclusion: Higher SUVmax at pretreatment 18F-FDG PET/CT was associated with better relapse free survival and overall survival in DLBCL patients after consolidation therapy with 131I-rituximab. However, because this study has a small number of patients, a phase 3 study with a larger number of patients is needed for clinical application in the future.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Consolidation Chemotherapy
  • Cyclophosphamide / therapeutic use
  • Disease-Free Survival
  • Doxorubicin / therapeutic use
  • Female
  • Fluorodeoxyglucose F18* / metabolism
  • Humans
  • Iodine Radioisotopes / therapeutic use
  • Lymphoma, Large B-Cell, Diffuse* / diagnostic imaging
  • Lymphoma, Large B-Cell, Diffuse* / drug therapy
  • Male
  • Middle Aged
  • Neoplasm Recurrence, Local / drug therapy
  • Positron Emission Tomography Computed Tomography
  • Prednisolone / therapeutic use
  • Prognosis
  • Radioimmunotherapy
  • Retrospective Studies
  • Rituximab / therapeutic use
  • Vincristine / therapeutic use

Substances

  • Iodine Radioisotopes
  • Iodine-131
  • Fluorodeoxyglucose F18
  • Rituximab
  • Vincristine
  • Doxorubicin
  • Cyclophosphamide
  • Prednisolone
  • 131I-rituximab

Grants and funding

This project was supported by a grant (no. 50547-2022) from the Korea Institute of Radiological and Medical Sciences (KIRAMS) funded by the Ministry of Science, ICT (MSIT), Republic of Korea. It was also supported by a grant (No. 2020R1A2C2102492) of the National Research Foundation (NRF) funded by the Ministry of Science and ICT (MSIT), Republic of Korea.