Radiologic Modalities and Response Assessment Schemes for Clinical and Preclinical Oncology Imaging

Abstract

Clinical drug trials for oncology have resulted in universal protocols for medical imaging in order to standardize protocols for image procurement, radiologic interpretation, and therapeutic response assessment. In recent years, there has been increasing interest in using large animal models to study oncologic disease, though few standards currently exist for imaging of large animal models. This article briefly reviews medical imaging modalities, the current state-of-the-art in radiologic diagnostic criteria and response assessment schemes for evaluating therapeutic response and disease progression, and translation of radiologic imaging protocols and standards to large animal models of malignant disease.

Keywords: Radiology; imaging; large animal model; standards; trial.

Figure 1

Example of normal contrast-enhanced abdominal CT scan in human patient; L, liver; K, kidney; P, pancreas; St, stomach; Sp, spleen.

Figure 2

Example of unremarkable contrast-enhanced abdominal MR imaging study of the abdomen in human patient; L, liver; St, stomach; Sp, spleen.

Figure 3

Example of normal fused abdominal PET-CT exam in human patient. L, liver; K, kidney; P, pancreas; St, stomach. Note background avidity of metabolically active liver and kidney (light orange color).

Figure 4

Arterial (Left) and venous (Right) phases of contrast enhanced CT scan performed in human patient demonstrate typical LI-RADS 5 mass (arrow), displaying typical arterial phase hyper enhancement, venous phase “washout,” and enhancing capsule.

Figure 5

Representative images displaying RECIST response after TACE treatment of HCC in human patient. Pretreatment (Left) contrast-enhanced CT scan depicts 10.6 cm diameter right lobe liver tumor (dashed line). Sequential post-treatment contrast-enhanced CT scans (Middle, Right) reveal ensuing size reduction to 7.5 cm (29% reduction, RECIST SD) and 5.0 cm (53% reduction, RECIST PR) diameter, respectively; high attenuation material at tumor periphery (arrows) represents chemotherapy emulsion.

Figure 6

Illustrative images demonstrating EASL response after TACE treatment of HCC in human patient. Pretreatment (Left) contrast-enhanced CT scan depicts 2.0 cm diameter left lobe liver tumor (arrow). Post-treatment contrast-enhanced MR imaging study (Right) shows no residual enhancing component (arrow), consistent with EASL CR.

Figure 7

Typical images displaying mRECIST response after TACE treatment of HCC in human patient. Pretreatment (Left) contrast-enhanced MR imaging exam depicts 5.0 cm diameter right lobe liver tumor (dashed line). Contrast-enhanced CT scan (Middle) after first treatment demonstrates 1.5 cm residual enhancing tumor (asterisk) (70% reduction, mRECIST PR). Retreatment pursued, and contrast-enhanced MR imaging scan (Right) after second treatment demonstrates no residual enhancing tumor (100% reduction, mRECIST CR).

Figure 8

Illustrative images demonstrating PERCIST response after locoregional treatment of liver tumor in human patient. Pretreatment (Left) PET-CT demonstrates FDG avid liver tumor (arrow). Post-treatment (Right) PET-CT shows normalization of SUL (arrow), consistent with PERCIST CR.

Figure 9

Example of normal contrast-enhanced porcine abdominal CT scan; L, liver; GB, gallbladder; St, stomach.

Figure 10

Example of unremarkable porcine MR imaging study: axial T1-weighted image (Left), axial T2-weighted image (Middle), and coronal T1-weighted post-contrast image (Right); L, liver; GB, gallbladder; St, stomach.