Nour-Eldin Abdelrehim Nour-Eldin MD, MSc, Presenter: Nothing to Disclose

Nagy Naguib Naeem Naguib MD, MSc, Abstract Co-Author: Nothing to Disclose

Julian Lukas Wichmann MD, Abstract Co-Author: Nothing to Disclose

Ahmed Fathy Emam MBBCh, Abstract Co-Author: Nothing to Disclose

Mohammed Ahmed Alsubhi BMBS, Abstract Co-Author: Nothing to Disclose

Thomas Josef Vogl MD, PhD, Abstract Co-Author: Nothing to Disclose

To determine the value contrast enhanced (CE-MRI) follow-up in the assessment of tumor response of microwave (MW) ablated pulmonary metastases by correlating the results with CE-CT.  

This prospective study included 130 ablation sessions for pulmonary metastases in 80 patients. CE-MRI Chest scanning was performed 1week before the ablation and at 24hours, 3, 6, 9 and12months post ablation. Thin section CT Volumetric measurement of the lesions was performed at the same time periods as a second parameter for comparison. The lesion MRI enhancement intensity in each study was estimated, and the ratio to the paraspinal muscle enhancement intensity at the same level was measured (Lesion Muscle Signal (LMS ratio).The correlations between post ablation follow-up CT volume of tumors and CE-MRI LMS ratio at the follow-up periods were assessed.  

The preablation tumor volumes range: 0.30-6.1cm (mean: 1.5cm³, SD:1.3). LMS ratio < 1was associated with post ablation reduction of tumor volume (denoting scaring),while LMS ratio>1were noted in: preablation due to high contrast enhancement of the tumor,in24h post ablation due to the inflammatory response associated with the thermal ablation and due to tumor residue or progress. Weak correlation was detected between the LMS-ratios and CT-volumetric changes in 24h post ablation. Strong correlation between the LMS ratios was estimated between the follow up periods of 3months(SpearmanR:0.62,p=0.0021),6months (SpearmanR:0.66,p=0.001),9months(SpearmanR:0.61,p<0.001)and 12months (Spearman R:0.7, p<0.00001).  

CE-MRI follow up of the MW ablated lung tumors can be used effectively to assess the tumor response to ablation using LMS ratio as a parameter of assessment.  

CE-MRI may be used for the evaluation of tumor response post pulmonary ablation therapy.

Nour-Eldin, N, Naguib, N, Wichmann, J, Emam, A, Alsubhi, M, Vogl, T, Role of MRI Chest  in the Assessment of Tumor Response Post Microwave Ablation of Pulmonary Metastases.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045691.html