1
|
Gormsen LC, Vendelbo MH, Pedersen MA, Haraldsen A, Hjorthaug K, Bogsrud TV, Petersen LJ, Jensen KJ, Brøndum R, El-Galaly TC. A comparative study of standardized quantitative and visual assessment for predicting tumor volume and outcome in newly diagnosed diffuse large B-cell lymphoma staged with 18F-FDG PET/CT. EJNMMI Res 2019; 9:36. [PMID: 31054023 PMCID: PMC6499846 DOI: 10.1186/s13550-019-0503-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 04/12/2019] [Indexed: 12/13/2022] Open
Abstract
Background Semi-automated quantitative measurement of metabolic tumor volume (MTV) for prognosis in diffuse large B-Cell lymphoma (DLBCL) has gained considerable interest lately. However, simple tumor volume measures may be inadequate for assessment of prognosis in DLBCL as other characteristics such as growth pattern and metabolic heterogeneity may be just as important. In addition, MTV measurements require delineation of tumor lesions by semi-automated software, which can be time-consuming. We hypothesized that a simple visual assessment of tumor volume performs as well as standardized MTV measurements in DLBCL prognostication. Materials and methods Quantitative and visual analyses of pre-therapy 18F-FDG PET/CT scans in 118 patients with newly diagnosed DLBCL were conducted. Quantitative analyses were performed using Hermes TumourFinder® to obtain MTV2.5 (SUV 2.5 cut-off) and MTV41 (41% SUVmax isocontour cut-off). Visual assessments included a binary prediction (good/poor prognosis) as well as tumor burden based on a visual analog scale (MTVVAS) and an estimated volume (eMTV). Three experienced nuclear medicine physicians who were blinded to clinical outcome performed visual evaluations. Progression-free survival was evaluated by Kaplan-Meier curves and log-rank test. Inter-observer variability was evaluated by Fleiss’ kappa for multiple observers. Results In the quantitative analysis, a ROC-determined MTV2.5 cut-off (log-rank p = 0.11) seemed to outperform MTV41 (log-rank p = 0.76) for PFS prediction. TLG2.5 (log-rank p = 0.14) and TLG41 (log-rank p = 0.34) were not associated with outcomes. By visual analysis, all three reviewers were able to stratify patients into good/poor prognosis (reviewer A log-rank p = 0.002, reviewer B log-rank p = 0.016, and reviewer C log-rank p = 0.012) with fair inter-observer agreement (Fleiss’ kappa 0.47). MTVVAS and eMTV were not consistently correlated with the outcome. Conclusion Predictions of outcome after first-line treatment for DLBCL were surprisingly good when left to the unsupervised, subjective judgment of experienced readers of lymphoma 18F-FDG-PET/CT. The study highlights the importance of non-standardized clinical judgments and shows potential loss of valuable prognostic information when relying solely on semi-automated MTV measurements.
Collapse
Affiliation(s)
- Lars C Gormsen
- Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, DK 8000 Aarhus C, Aarhus, Denmark.
| | - Mikkel H Vendelbo
- Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, DK 8000 Aarhus C, Aarhus, Denmark.,Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Mette Abildgaard Pedersen
- Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, DK 8000 Aarhus C, Aarhus, Denmark
| | - Ate Haraldsen
- Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, DK 8000 Aarhus C, Aarhus, Denmark
| | - Karin Hjorthaug
- Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, DK 8000 Aarhus C, Aarhus, Denmark
| | - Trond Velde Bogsrud
- Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, DK 8000 Aarhus C, Aarhus, Denmark.,PET Centre, University Hospital of North Norway, Tromso, Norway
| | - Lars J Petersen
- Department of Nuclear Medicine, Clinical Cancer Research Center, Aalborg University Hospital, Aalborg, Denmark
| | - Karen Juul Jensen
- Department of Hematology, Odense University Hospital, Odense, Denmark
| | - Rasmus Brøndum
- Department of Hematology, Aalborg University Hospital, Aalborg, Denmark
| | - Tarec C El-Galaly
- Department of Hematology, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
| |
Collapse
|