Computed Tomography Perfusion of Squamous Cell Carcinoma of the Upper Aerodigestive Tract

Abstract

We obtained baseline perfusion data for head and neck squamous cell cancers and compared it with adjacent normal structures. Our initial results suggest that CT perfusion parameters (CP, BF, BV, and MTT) can be used to help differentiate head and neck squamous cell carcinoma (SCCA) from adjacent normal tissue.

Optimization of Perfusion CT Protocol for Imaging of Extracranial Head and Neck Tumors

“…11,18 Although the estimation of the CT-based first-pass tracer kinetic parameters like F in extacranial head and neck tumors has not been validated using a gold standard like radio-labeled H 2 O positron emission tomography (PET) imaging, the derived functional values in the initial studies [8][9][10] (which were the input parameter in our protocol) appear consistent with the tumor physiology in terms of increased cell proliferation and neoangiogenesis in order to satisfy the increased demand in blood supply. These phenomena result in elevated blood flow F (multiple abnormal low-resistance shunts of the newly formed vessels where the blood rapidly flows), elevated blood volume v 1 (as a measure of the tumor vasculature), and increased permeability-surface area product PS (due to immature newly formed vessels with increased fenestration which results in rapid extravasation of the contrast agent into the interstitial extracellular space).…”

“…The parameter values used in this study were obtained from a previous study 8 in our institution after institutional review board approval and informed consent from the patients as well as from similar studies in literature. [9][10] These parameter values are F = 70 ml/min/100 g, v 1 = 5 ml/100 g, k 21 = 3.4 min −1 , and k 12 =0.85 min −1 , giving PS= 17 ml/min/100 g.…”

“…We attempted to transform this problem into two subproblems of locating local suboptimal values, which can be systemically approached in the following manner. We first fix N at the conventionally acceptable value of 50 and study the parameter errors for various values of N ICS (10,15,20,25,30,35,40), Δt (0.5, 1, 1.5, and 2 s), and α (0.05, 0.06, 0.07…, 0.2). Optimal values of N ICS , Δt, and α (and hence T) were manually identified using contour plots of these variables as a function of the perfusion parameter errors.…”

“…The deconvolution method used also for the calculation of permeability changes has been the method of choice in several reports in recent literature. [8][9][10] Although the acquisition time of DCE-CT data in these studies varies from 50-55 s, other variations in imaging protocols among these studies are apparent. The delay before the initiation of the contrast-enhanced scans can be up to about 6 s after contrast injection, and the injection rate is not standardized, which results in different durations of the contrast agent passage in the tissue microvasculature.…”

Perfusion CT in Squamous Cell Carcinoma of the Upper Aerodigestive Tract: Long-Term Predictive Value of Baseline Perfusion CT Measurements

“…[4][5][6][7][8] In particular, the necessity to detect early response to therapy and avoid any time delay in nonresponders has led to examining the predictive value of perfusion imaging, which might help in tailoring the therapy regimen on an individual basis. 9,10 Early proponents of perfusion studies have also demonstrated in a clinical setting that semi-or quantitatively estimated tumor perfusion might predict the outcome after definitive radiation therapy.…”