PET/CT and MR improve interobserver agreement in primary tumor determination for radiotherapy in esophageal squamous cell cancerŠečerov Ermenc, Ajra (Avtor) Peterlin, Primož (Avtor) Velenik, Vaneja (Avtor) Jeromen, Ana (Avtor) But-Hadžić, Jasna (Avtor) Anderluh, Franc (Avtor) Šegedin, Barbara (Avtor) magnetic resonancepositron emission tomographysquamous cell carcinomaprimary tumorThe aim of the study was to evaluate interobserver variability in the determination of the primary tumor for radiotherapy treatment planning in esophageal squamous cell carcinoma (ESCC). Methods: Sixteen patients with locally advanced ESCC were included in the analysis. In all patients positron emission tomography with computed tomography (PETC/CT) and magnetic resonance (MR) scans for radiotherapy planning were performed. Five experienced radiation oncologists delineated the primary tumor based on CT alone, MR alone, PET/CT, CT with fused MR and PET/CT with fused MR. Mean tumor volumes were calculated for each patient and imaging modality. The generalized conformity index (CIgen) was calculated to assess agreement in tumor determination. Results: The mean tumor volumes and CIgen for CT alone, MR alone, PET/CT, CT with fused MR and PET/CT with fused MR were 33.1 cm3, 30.2 cm3, 38.1 cm3, 31.9 cm3, 36.2 cm3 and 0.59, 0.64, 0.66, 0.63, 0.71, respectively. CIgen was significantly higher using PET/CT with fused MR compared to CT (p < 0.001) and PET/CT (p = 0.002) and using PET/CT compared to CT (alone) (p = 0.003). Conclusions: Our study showed higher agreement in primary tumor determination in ESCC using PET/CT compared to CT alone. Higher agreement was also found using PET/CT with fused MR compared to CT alone and PET/CT.MDPI, Basel, Switzerland20252025-11-06 03:38:30Neznano24005UDK: 616-006ISSN pri članku: 2075-4418DOI: 10.3390/diagnostics15060690COBISS_ID: 230835203Basel, Switzerlandsl