Body perfusion CT: technique, clinical applications, and advances.

Dynamic contrast-enhanced computed tomography (DCE-CT) assesses the vascular support of tumours through analysis of temporal changes in attenuation in blood vessels and tissues during a rapid series of images acquired with intravenous administration of iodinated contrast material. Commercial software for DCE-CT analysis allows pixel-by-pixel calculation of a range of validated physiological parameters and depiction as parametric maps. Clinical studies support the use of DCE-CT parameters as surrogates for physiological and molecular processes underlying tumour angiogenesis. DCE-CT has been used to provide biomarkers of drug action in early phase trials for the treatment of a range of cancers. DCE-CT can be appended to current imaging assessments of tumour response with the benefits of wide availability and low cost. This paper sets out guidelines for the use of DCE-CT in assessing tumour vascular support that were developed using a Delphi process. Recommendations encompass CT system requirements and quality assurance, radiation dosimetry, patient preparation, administration of contrast material, CT acquisition parameters, terminology and units, data processing and reporting. DCE-CT has reached technical maturity for use in therapeutic trials in oncology. The development of these consensus guidelines may promote broader application of DCE-CT for the evaluation of tumour vascularity. Key Points
 • DCE-CT can robustly assess tumour vascular support
 • DCE-CT has reached technical maturity for use in therapeutic trials in oncology
 • This paper presents consensus guidelines for using DCE-CT in assessing tumour vascularity

Current status and guidelines for the assessment of tumour vascular support with dynamic contrast-enhanced computed tomography

Purpose: To prospectively monitor changes in rectal cancer perfusion after combined neoadjuvant chemotherapy and radiation therapy with perfusion computed tomography (CT) and to evaluate whether perfusion CT findings correlate with response to therapy. Materials and Methods: The study was approved by the institutional ethics committee of the European Institute of Oncology; written informed consent was obtained from all participants before the study. Twenty-five patients with rectal adenocarcinoma (18 men, seven women; age range, 42–72 years; mean age, 61.3 years) underwent perfusion CT; all of them underwent neoadjuvant chemotherapy and radiation therapy, followed by surgery. In 19 patients, perfusion CT was repeated after chemotherapy and radiation therapy. Dynamic perfusion CT was performed for 50 seconds after intravenous injection of contrast medium (40 mL, 370 mg iodine per milliliter, 4 mL/sec). Blood flow (BF), blood volume (BV), mean transit time, and permeability–surface area product (PS) were co...

CT perfusion for the monitoring of neoadjuvant chemotherapy and radiation therapy in rectal carcinoma: initial experience.

OBJECTIVE. This article summarizes the current status of CT perfusion in oncologic imaging, including lesion characterization, staging, prediction of patient outcome or response to therapy, assessment of response to different therapies, and evaluation of tumor relapse. Technical limitations and drawbacks of CT perfusion are also discussed. CONCLUSION. Tumor angiogenesis is essential for cancer growth and provides an attractive target for oncologic therapies. CT perfusion is an emerging imaging tool that provides both qualitative and quantitative information regarding tumor angiogenesis.

https://www.ajronline.org/doi/pdf/10.2214/AJR.11.8476

CT Perfusion in Oncologic Imaging: A Useful Tool?

Purpose: To establish the relationships between quantitative perfusion computed tomography (CT) parameters—specifically, primary tumor blood flow, blood volume, transit time, and permeability surface-area product—and immunohistologic markers of angiogenesis in colorectal cancer. Materials and Methods: After institutional review board approval and informed patient consent were obtained for this prospective study, 23 patients (11 men, 12 women; mean age, 68.4 years; age range, 34.8–87.1 years) with colorectal adenocarcinoma underwent a 65-second perfusion CT examination, and tumor blood flow, blood volume, mean transit time, and permeability surface-area product were determined. After surgery, resected specimens were sectioned and stained immunohistochemically to identify CD34 for quantification of microvessel density (MVD), to identify smooth muscle actin for assessment of pericyte coverage index, to identify vascular endothelial growth factor (VEGF), and to identify glucose transporter protein (GLUT-1). P...

Colorectal tumor vascularity: quantitative assessment with multidetector CT--do tumor perfusion measurements reflect angiogenesis?

AIM: To investigate the correlation between microvessel density and spiral CT perfusion imaging in colorectal carcinoma.

METHODS: Thirty-seven patients, with histologically proven colorectal carcinoma, underwent water enema spiral CT scan. The largest axial surface of the primary tumor was searched on unenhanced spiral CT images. At this level, the enhanced dynamic scan series was acquired. Time-density curves (TDC) were created from the region of interest drawn over the tumor, target artery by Toshiba Xpress/SX spiral CT with perfusion functional software. Then the perfusion was calculated. Microvessel density (MVD) was evaluated using immunohistochemical staining of surgical specimens with anti-CD34, and then MVD was correlated with perfusion.

RESULTS: MVD of colorectal carcinomas was 33.11-173.44, mean 87.28, and perfusion was 15.60-64.80 mL/min/ 100 g, mean 39.74 mL/min/100 g. MVD and perfusion were not associated with invasive depth, metastasis and disease stage, and they all decreased with increasing Dukes’ stage, but no significant correlation was found between them (r = 0.18, P = 0.29).

CONCLUSION: There is no significant correlation between MVD and perfusion. Neovascularizaton and perfusion are highly presented in early colorectal carcinoma. CT perfusion imaging may be more suited for assessing tumorigenesis in colorectal carcinoma than histological MVD technique.

Quan-fei Meng

Papers

Tumor angiogenesis and dynamic CT in colorectal carcinoma: Radiologic-pathologic correlation

Evaluation of angiogenesis in colorectal carcinoma with multidetector-row CT multislice perfusion imaging.