Predictive Value of PET Response Combined with Baseline Metabolic Tumor Volume in Peripheral T-Cell Lymphoma Patients

J Nucl Med. 2018 Apr;59(4):589-595. doi: 10.2967/jnumed.117.193946. Epub 2017 Sep 1.


Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of aggressive non-Hodgkin lymphomas with poor outcomes on current therapy. We investigated whether response assessed with PET/CT combined with baseline total metabolic tumor volume (TMTV) could detect early relapse or refractory disease. Methods: From 7 European centers, 140 patients with nodal PTCL who underwent baseline PET/CT were selected. Forty-three had interim PET (iPET) performed after 2 cycles (iPET2), 95 had iPET performed after 3 or 4 cycles (iPET3/4), and 96 had end-of-treatment PET (eotPET). Baseline TMTV was computed with a 41% SUVmax threshold, and PET response was reported using the Deauville 5-point scale. Results: With a median of 43 mo of follow-up, the 2-y progression-free survival (PFS) and overall survival (OS) were 51% and 67%, respectively. iPET2-positive patients (Deauville score ≥ 4) had a significantly worse outcome than iPET2-negative patients (P < 0.0001, hazard ratio of 6.8 for PFS; P < 0.0001, hazard ratio of 6.6 for OS). The value of iPET3/4 was also confirmed for PFS (P < 0.0001) and OS (P < 0.0001). The 2-y PFS and OS for iPET3/4-positive (n = 28) and iPET3/4-negative (n = 67) patients were 16% and 32% versus 75% and 85%, respectively. The eotPET results also reflected patient outcome. A model combining TMTV and iPET3/4 stratified the population into distinct risk groups (TMTV ≤ 230 cm3 and iPET3/4-negative [2-y PFS/OS, 79%/85%]; TMTV > 230 cm3 and iPET3/4-negative [59%/84%]; TMTV ≤ 230 cm3 and iPET3/4-positive [42%/50%]; TMTV > 230 cm3 and iPET3/4-positive [0%/18%]). Conclusion: iPET response is predictive of outcome and allows early detection of high-risk PTCL patients. Combining iPET with TMTV improves risk stratification in individual patients.

Keywords: PET/CT; PTCLs; interim PET; lymphoma; metabolic tumor volume.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Female
  • Humans
  • Lymphoma, T-Cell, Peripheral / diagnostic imaging
  • Lymphoma, T-Cell, Peripheral / metabolism
  • Lymphoma, T-Cell, Peripheral / pathology*
  • Lymphoma, T-Cell, Peripheral / therapy*
  • Male
  • Middle Aged
  • Positron Emission Tomography Computed Tomography*
  • Prognosis
  • Retrospective Studies
  • Treatment Outcome
  • Tumor Burden*
  • Young Adult