LENFOMA HASTALARINDA PET-BT İLE EVRELEME, YANIT VE PROGNOSTİK DEĞERLENDİRMELERİN İNCELENMESİ

Abstract

Öz, RŞ. Evaluation of Staging, Response and Prognostic Evaluations with PET-CT in Lymphoma Patients. Hacettepe University Faculty of Medicine, Department of Internal Medicine, Thesis in Internal Medicine Specialty, Ankara-Turkiye, 2023

Total metabolic tumor volume (TMTV) is a new parameter derived from baseline PET-CT data. TMTV is the sum of the metabolic volume of each lesion and indicates the most metabolically active part of the tumor. TMTV can be measured from PET-CT images using various software and techniques. In the prediction of progression-free survival (PFS) and overall survival (OS) in lymphoma subtypes, TMTV performs better than basic quantitative PET-CT measurements. In this study, we aimed to retrospectively examine the main features of patients diagnosed with Hodgkin (HL) and non-Hodgkin lymphoma (NHL) and reveal the prognostic factors that affect survival. The primary endpoint was to examine the effect of baseline TMTV on PFS and OS. In order to do this, a total of 87 patients who were diagnosed with HL (n:30) and NHL (n:57) between 2010 and 2021 were included in this study. Patients' baseline, interim and end-of-treatment TMTV, baseline PET-CT TMTV differences with interim and end-of-treatment PET-CT TMTV, volume changes based on the percentage of TMTV between the baseline and interim PET (ΔTMTVi) and between baseline and end-of-treatment PET-CT (ΔTMTVeot) values were calculated. Optimal baseline TMTV cutoff was 3745,38 mm2xSUVmax in NHL patients. Patients with high vs low baseline TMTV showed worse/higher OS and this difference was close to the statistical significance limit (91,6; 112,3 months, respectively), (p=0,054). HL patients with high baseline TMTV showed worse OS but this difference was not found to be statistically significant (p=0,65). No correlation was found between baseline TMTV value and PFS in HL and NHL patients (p=0,28; p=0,53). Baseline PET-CT TMTV and interim PET-CT TMTV difference associated with PFS in HL patients (p=0,04). Baseline PET-CT TMTV and end-of-treatment PET-CT TMTV difference associated with OS in HL patients (p=0,01) and associated with PFS in NHL patients (p=0,02). In HL and NHL patients, PFS was found to be worse in patients with ΔTMTVeot below the cut off value (p<0,001). In conclusion, although interim PET-CT is a guiding imaging method in treatment, it was not effective in predicting OS and PFS in NHL, while in HL it was only effective in predicting PFS. Essentially, the difference between end-of-treatment and baseline PET-CT TMTV value was found to be effective in predicting of OS and PFS. In particular, it was found to be effective in predicting of OS in HL patients and PFS in NHL patients. Baseline PET-CT TMTV value was statistically significant at the border in predicting OS in NHL patients.