Median RECIST diameter of all included tumours was 40 mm (range: 18–82 mm). In the discovery cohort, we found significant ( p = 0.03) underestimation of tumour diameter on CT compared with gross pathology (Δdiameter 3D = −5.7 mm), while realistic diameter measurements were obtained from FD maps (Δdiameter 3D = 0.6 mm) and mpMRI (Δdiameter 3D = −0.9 mm), with excellent correlation between the two ( R 2 = 0.88). In the validation cohort, CT also systematically underestimated tumour size in comparison to mpMRI (Δdiameter 3D = −10.6 mm, Δvolume = −10.2 mL), especially in larger tumours. In contrast, FD map measurements agreed excellently with mpMRI (Δdiameter 3D = +1.5 mm, Δvolume = −0.6 mL). Quantitative perfusion chaos was significantly ( p = 0.001) higher in the tumour rim (FD rim = 4.43) compared to the core (FD core = 4.37) and remote pancreas (FD pancreas = 4.28). FD quantifies perfusion chaos-the underlying pathophysiological principle-and can separate the more chaotic tumour rim from the tumour core and adjacent non-tumourous pancreas tissue.Ĭomputed tomography (CT) plays an important role in staging pancreatic ductal adenocarcinoma (PDA) in clinical routine.Fractal analysis provides maps of the fractal dimension (FD), which enable a more reliable and size-independent measurement using gross pathology or multi-parametric MRI as reference standards.CT-based measurement of tumour size in pancreatic adenocarcinoma systematically underestimates both tumour diameter (Δdiameter = −10.6 mm) and volume (Δvolume = −10.2 mL), especially in larger tumours.In PDA, fractal analysis visualises perfusion chaos in the tumour rim and improves size measurement on CT in comparison to gross pathology and mpMRI, thus compensating for size underestimation from routine CT. The current edition (8 th) of the American Joint Commission on Cancer (AJCC) staging system for pancreatic adenocarcinoma differs from earlier versions in that it introduces a size-based definition for T-staging. This size-based definition has been validated and prognostic implications have been derived. However, it is also known that tumour size, measured either as diameter or volume, is frequently underestimated on CT compared with multi-parametric magnetic resonance imaging (mpMRI) or pathological workup of the resected specimen.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |