XXXX concentration as a perfusion surrogate marker in oncology: Further elucidation of the underlying mechanisms using Volume Perfusion CT with 80 kVp.

@entity1 @entity1496 @entity706 @entity5 @entity157
OBJECTIVES: To assess the value of @entity1496 concentration (IC) in computed tomography data acquired with 80  kVp, as a surrogate for perfusion imaging in @entity157 ( @entity157 ) and @entity706 by comparing @entity1496 related attenuation (IRA) with quantitative Volume Perfusion CT (VPCT)-parameters. METHODS: VPCT-parameters were compared with intra-tumoral IC at 5 time points after the aortic peak enhancement (APE) with a temporal resolution of 3.5  sec in untreated 30 @entity157 and 30 @entity706 @entity1 . RESULTS: Intra-tumoral perfusion parameters for @entity157 showed a blood flow (BF) of 52.7        17.0  mL/100  mL/min, blood volume (BV) 12.6        4.3  mL/100  mL, arterial liver perfusion (ALP) 44.4        12.8  mL/100  mL/min. Lesion IC 7  sec after APE was 133.4        57.3  mg/100  mL. Lymphoma showed a BF of 36.8        13.4  mL/100  mL/min, BV of 8.8        2.8  mL/100  mL and IC of 118.2        64.5  mg/100  mL 3.5  sec after APE. Strongest correlations exist for VPCT-derived BF and ALP with IC in @entity157 7  sec after APE (r   =   0.71 and r   =   0.84) and 3.5  sec after APE in @entity706 (r   =   0.77). Significant correlations are also present for BV (r   =   0.60 and r   =   0.65 for @entity157 and @entity706 , respectively). CONCLUSIONS: We identified a good, time-dependent agreement between VPCT-derived flow values and IC in @entity157 and @entity706 . Thus, CT-derived ICs 7  sec after APE in @entity157 and 3.5  sec in @entity706 may be used as surrogate imaging biomarkers for @entity5 perfusion with 80  kVp. KEY POINTS:     @entity1496 concentration derived from low kVp CT is regarded as perfusion surrogate     Correlation with Perfusion CT was performed to elucidate timing and histology dependencies     Highest correlation was present 7  sec after aortic peak enhancement in @entity157     In @entity706 , highest correlation was calculated 3.5  sec after aortic peak enhancement     With these results, further optimization of Dual energy CT protocols is possible.
