Gaurav Shyam Desai MBBS, Presenter: Nothing to Disclose

Eva-Maria Ratai PhD, Abstract Co-Author: Nothing to Disclose

Nick Boschetti, Abstract Co-Author: Nothing to Disclose

Kenneth Tanabe, Abstract Co-Author: Nothing to Disclose

Sanjeeva P. Kalva MD, Abstract Co-Author: Nothing to Disclose

Dushyant V. Sahani MD, Abstract Co-Author: Research collaboration, General Electric Company Consultant, Bracco Group

1.To investigate if the 1H-MRS profile can characterize liver metastases from different primaries. 2.To study the changes in 1H-MRS and FDG-PET in the liver tumor and normal liver following intraarterial treatment with herpes simplex oncolytic virus (rRp450) treatment.

In this ongoing IRB approved study, 11 patients (6M: 5F) with liver metastases from the following primaries: CRC (n=3) melanoma (n=2) and one each from duodenal, neuroendocrine, ovarian, rhabdomyosarcoma, breast and pancreatic adenocarcinoma) were enrolled for FDG-PET and 1H-MRS (1.5-T system, GE). Index lesion in the right lobe and uninvolved liver were investigated using a single voxel, PRESS sequence (TE = 144 milliseconds, FOV=22, thickness=20, skip=20, NEX=8, Phase/Freq encode=192/256). In 11/4 1H-MRS was repeated at 2-weeks following intra-arterial delivery of herpes simplex oncolytic virus (rRp450) in the liver. The data was processed using LC Model (Version 6.2, Stephen Provencher Inc). Choline concentration and choline/lipid (C/L) ratio was calculated for the tumor and background liver. The SUVmax ([g/mL]) of the lesion was recorded.

Choline and C/L were distinct for tumor (0.003±0.002, 0.511±0.85) and normal liver (0.009±0.004, 0.25±0.26, p=0.03). Breast metastases showed substantial differences in spectral peaks of choline (0.006) and C/L ratio (2.72) than for other tumors. Post treatment, 2 of 4 tumors (CRC) showed decrease in choline and C/L (0.62 vs. 0.8 and 0.27 vs. 0.33) with 1 in FDG [(14.6 vs. 6.5) R=0.6, p<0.01]. Normal liver showed decrease in lipid peak and an increase in C/L ratio (L and C/L: 0.118±0.081 and 0.077±0.021 before and 0.565±0.326 and 0.101±0.103 post, p=0.3).

The liver tumors show a distinct spectral profile from background tissue on 1H-MRS. Except for metastases from breast adenocarcinoma, tumors from other primaries show an overlap in their spectral profile. Following treatment, both 1H-MRS and PET demonstrated changes in tumor cellular activity and background liver.

1H-MRS predicts tumor and liver cell changes after intra-arterial treatment, potentially serving as a non-invasive biomarker for assessing tissue composition,early treatment effects and drug toxicity

Desai, G, Ratai, E, Boschetti, N, Tanabe, K, Kalva, S, Sahani, D, 1H-MRS Patterns in Liver Metastases and Changes Following Herpes Simplex Oncolytic Virus (rRp450) Treatment in Comparison to FDG-PET.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12034753.html