Introduction: Contrast Enhanced Ultrasound (CEUS) is a dynamic and continuous modality that offers a real-time direct view of vascularization and flow distribution patterns of different organs and type of tumors. Nevertheless its intraoperative use for brain tumors visualization has been performed few times, and there are no guidelines on this regard. Furthermore a thorugh characterization of cerebral glioma had never been performed.
Main aim of the study is to describe the different patterns of enhancement of cerebral gliomas using the CEUS technique.
Methods: We performed intra-operative CEUS (iCEUS) in an off-label setting in 69 patients undergoing surgery for cerebral glioma. Ultrasound contrast agent (UCA) (sulphur hexafluoride (SonoVue - Bracco - Italy)) was administered intra-venously and the lesion scanned for at least 120 seconds.
An on-site and a post-procedural semi-quantitative analysis was performed for each case, evaluating CEUS parameters, following the guidelines of the European Federation for Ultrasound in Medicine and Biology (EFSUMB): timing, degree of CE and contrast distribution.
Results: Both low grade glioma (LGG) and high grade glioma (HGG) appear hyper-echoic relative to the adjacent brain parenchyma on B-mode US. Different contrast enhancement patterns were observed according to lesion characteristics: LGG showed a dotted or diffuse appearance with a slower and delayed arterial and venous phase compared with HGG, whereas HGG have a more nodular, non-homogeneous appearance, with faster and major contrast enhancement.
Conclusions: Our study characterizes for the first time, human brain glioma with iCEUS, giving us further insight regarding the biology of these tumors: being a dynamic and continuous modality it offers a real-time direct view of the tumor perfusion and of the afferent and efferent vessels. CEUS is a fast, safe, dynamic, real-time, economic tool that might be helpful during surgery in differentiating malignant and benign gliomas and refining the surgical strategy.
Patient Care: iCEUS might be helpful for the surgeon to differentiate between tumor/edematous brain in HGG, while it will show anaplastic areas within otherwise considered low-grade lesions. After gross tumor removal CEUS will also be used to highlight tumor remnants, thus maximizing resection avoiding neurological sequelae due to damaged healthy brain tissue.
Learning Objectives: To understand glioma perfusion patterns and describe the different features of enhancement of cerebral gliomas using the CEUS technique.
References: - Prada F, Perin A, Martegani A, Aiani L, Solbiati L, Lamperti M, Casali C, Legnani F, Mattei L, Saladino A, Saini M, DiMeco F. Intraoperative Contrast Enhanced Ultra-Sound (iCEUS) for Brain Tumor Surgery. Neurosurgery, May 2014. Epub ahead of print.
- Harrer JU, Hornen S, Oertel MF, Stracke CP, Klötzsch C. Comparison of perfusion harmonic imaging and perfusion mr imaging for the assessment of microvascular characteristics in brain tumors. Ultraschall Med. 2008;29(1):45–52. doi:10.1055/s-2007-963413.
- Piscaglia F, Bolondi L; Italian Society for Ultrasound in Medicine and Biology (SIUMB) Study Group on Ultrasound Contrast Agents.The safety of Sonovue in abdominal applications: retrospective analysis of 23188 investigations.Ultr asound Med Biol. 2006 Sep;32(9):1369-75.
- Quaia E, Alaimo V, Baratella E, Pizzolato R, Cester G, Medeot A, Cova MA (2010) Effect of observer experience in the differentiation between benign and malignant liver tumors after ultrasound contrast agent injection. J Ultrasound Med 29:25–36.