Comparison between nonspecific and necrosis-avid gadolinium contrast agents in vascular disrupting agent-induced necrosis of rodent tumors at 3.0T.

Abstract

OBJECTIVE:

: To compare a commercial contrast agent (CA) Dotarem and a necrosis-avid CA (NACA) for their ability to evaluate the therapeutic necrosis with a vascular disrupting agent (VDA) on magnetic resonance imaging in rodent liver tumors to determine which could better correlate with the histopathologic outcome.

METHODS:

: After the VDA treatment, 16 rats with 32 liver rhabdomyosarcomas were randomized into Dotarem and NACA groups (n = 8 per group) for both interindividual and intraindividual comparisons. T2-weighted imaging, T1-weighted imaging (T1WI), contrast-enhanced T1-weighted imaging (CE-T1WI), and diffusion-weighted imaging were performed at baseline, after VDA treatment and CA injections. The enhancing efficacy of CAs at immediate and delayed enhancement on CE-T1WI in viable tumor and necrosis was compared. Tumor necrosis ratios calculated from NACA and Dotarem were compared and correlated with gold-standard histopathology.

RESULTS:

: On the immediate CE-T1WI, viable tumor was enhanced by either CA. On the delayed CE-T1WI at 30 minutes, both CAs failed to demarcate viable tumor from necrosis. At 24 hours post-NACA, the necrosis was clearly distinguished from viable tumor and thus derived necrosis ratio matched that from histopathology (P = 0.99); necrosis ratio from Dotarem was significantly lower than that from NACA and histopathology (P < 0.05, both), with a higher correlation of NACA than that of Dotarem with histopathology (r = 0.99 vs. r = 0.82).

CONCLUSIONS:

: NACA better evaluated VDA-induced tumor necrosis than nonspecific CA on T1WI in tumor models of rat liver. NACA showed a closer correlation with histopathology than nonspecific CA for the delineation of true necrosis. Delayed enhancement on T1WI with nonspecific CA is not suitable for the assessment of VDA-induced tumor necrosis.

• Authors: Huaijun Wang, Marlein Miranda Cona, Feng Chen, Junjie Li, Jie Yu, Yuanbo Feng, Ronald Peeters, Frederik De Keyzer, Guy Marchal, Yicheng Ni
• Journal: Investigative radiology (Invest Radiol) Vol. 46 Issue 9 Pg. 531-8 (Sep 2011) ISSN: 1536-0210 [Electronic] United States
• PMID: 21577133 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Biomarkers, Tumor
• Contrast Media
• Gadolinium DTPA

Topics

• Animals
• Biomarkers, Tumor
• Contrast Media (adverse effects)
• Disease Models, Animal
• Gadolinium DTPA (adverse effects)
• Liver Neoplasms (diagnosis, pathology)
• Magnetic Resonance Imaging
• Male
• Necrosis (chemically induced)
• Rats
• Rhabdomyolysis (diagnosis, pathology)
• Risk Factors
• Statistics as Topic
• Vascular Diseases (diagnosis)