Zhiyang Zhou PhD, Abstract Co-Author: Nothing to Disclose

Jiaying Gong, Presenter: Nothing to Disclose

Wuteng CAO, Abstract Co-Author: Nothing to Disclose

Zhong-Ping Zhang MMedSc, Abstract Co-Author: Nothing to Disclose

Yanbang Lian, Abstract Co-Author: Nothing to Disclose

To compare the diagnostic accuracy of using whole-body diffusion-weighted imaging (WB-DWI) at 1.5T and FDG-PET-CTin the dectection of recurrence and metastases in gastrointestinal cancer patients and to assess the modification of ADC value between metastases and normal tissues.

Twenty-eight consecutive patients diagnosedwith gastrointestinal cancer and suspected tumor recurrenceand 18 healthy controls were recruited and underwent both WB-DWI at 1.5T and PET-CT examinations for the staging of lymph node and distant metastases. PET-CT and histology and/or a clinical follow-up of 3-6 months served as a standard reference. Agreement between WB-DWI and FDG-PET-CT on detecting recurrence and distant metastases was compared using kappa statistics.Diagnostic accuracy, sensitivity, specificity, negative predictive value, and positive predictive value were calculated for each subject. Additionally,the difference of ADC values between normal tissues in controls and metastases were compared.

Tumor recurrence was observed in 5 of 28 patients. Lymph node involvement was determined in 20/28 cases as N-positive in PET-CT and in 18/28 in WB-DWI. M-stage was evaluated for liver metastases, lung, adrenal glandand, peritoneal, and bone. One brain metastasiswas observedin 1 patient usingWB-DWI. No statistically significant difference (t=1.332, P=0.194) of overall diagnostic performances between PET-CT and WB-DWI was observed.WB-DWI demonstratedsatisfying agreement with PET-CT (κ=0.877) in the detection of recurrence and distant metastases. Applying WB-DWI imaging with b=600s/mm2, statistically significant differences of the ADC value were observed between metastatic lymph nodes and normal nodes, metastasis of liver and normal liver, and metastasis of bones and normal bones, respectively(P<0.05).

WB-DWI provides non-radiating imaging for staging of gastrointestinal tumors and offers consistent diagnostic performances withPET-CT. In addition, the ADC value can be applied in the determination of tumor metastasis.

WB-DWI can be applied to stage gastrointestinaltumors and ADC is reliable in the identification of tumor metastasis.

Zhou, Z, Gong, J, CAO, W, Zhang, Z, Lian, Y, Whole-body Diffusion-weighted Imaging at 1.5T Compared with FDG-PET-CT for the Detection of Recurrence and Metastases in Patients with Gastrointestinal Tumors.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14015441.html