Shudong Hu MD, PhD, Presenter: Nothing to Disclose

To investigate the correlation between iodine concentration (IC) for quantitative of spectral CT and maximum standardized uptake value (SUVmax) of 18F-FDG-PET-CT to evaluate the therapeutic effect of interstitial brachytherapy on transplantation tumor of human pancreatic carcinoma in Balb/c-nu mice.

Xenograft models were created by subcutaneous injection of Swl990 human pancreatic cancer cell suspensions into the immunodeficient Balb/c-nu mice. Twenty mice bearing Swl990 human pancreatic cancer cell xenografts were randomly separated into two groups: experimental (n = 10; 1.0 mCi) and control (n = 10; 0 mCi). After 2 weeks treatment, spectral CT and 18F-FDG microPET-CT scan were performed. The iodine concentration (IC) in the lesions were measured and normalized to the muscle tissue as nIC. The relationships between the nIC and SUVmax of the transplantation tumors were analyzed. 

The nIC of the lesion was significantly lower than that in two groups during the multiphase scan. Our results showed that before treatment the SUVmax values among two groups had no significant statistical difference. Two weeks after treatment the SUVmax and 125I seed implant group were significantly lower than before, while for the empty seed group there were no significant difference compared with before treatment. The nIC values of the three-phase scans have certain positive correlation with the SUVmax values (r = 0.64, p < 0.05; r = 0.51, p < 0.05; r = 0.71, p < 0.05 in the 10，25 and 60 s phase respectively).

Spectral CT could serve as a valuable functional imaging modality as the nIC correlates with SUVmax of 18FDG PET-CT for evaluating the therapeutic effect of 125I interstitial brachytherapy in a pancreatic carcinoma xenograft.

Spectral CT offers opportunities to assess the therapeutic response of pancreatic cancer.

Hu, S, Functional Imaging of Interstitial Brachytherapy in Pancreatic Carcinoma Xenografts Using Spectral CT: How Does Iodine Concentration Correlate with Standardized Uptake Value of 18FDG-PET-CT?.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14005955.html