Abstract:
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Purpose: Nodal status is an independent prognostic factor in cervix cancer and also affects whether surgery or radiation is considered for primary therapy. To our knowledge studies with dynamic contrast enhanced (DCE) MRI have not shown a clear relationship between DCE derived parameters and nodal status in cervix cancer. The purpose of the study was to determine if parameters derived from DCE CT were related to patient nodal status in cervix cancer.
Methods and Materials: DCE CT was performed through the cervix tumors of 27 patients prior to radiation therapy. Tumor size was calculated using the mean of 3 orthogonal measurements on MRI. Images were acquired using a multi-row-detector helical CT (GE Lightspeed) with the following parameters: 120kV, 60mA, 5mm slice thickness. Non-ionic contrast was injected at 3cc/s and images obtain at 1/s for 120s and 1/15s for 60s from the time of injection. DCE-CT data was analyzed using CT Perfusion 3 software (GE Medical Systems) to obtain mean Blood Volume (BV), Blood flow (BF), Mean Transit Time (MTT) and permeability surface area product (PS). Mean Time to peak (TTP), peak enhancement (PE), residual enhancement (RE) and initial slope (IS) were also calculated as were the percentage of pixels with BF values <50 and <100ml/s/100g using in-house software. This was done for the whole tumor as well as 3 concentric tumor regions representing the outer third, mid portion and inner third of the tumor. These parameters were compared between patients with positive or negative nodal status. The presence of one or more abdominal or pelvic nodes £1cm in short axis on CT or MRI was considered evidence of positive nodal status.
Results: Mean tumor size was 3.8cm, (range 1.4-6.7cm). There was a significantly higher BV in those patients with positive nodes (26.7 vs 19.5ml/100g, p < 0.007). MTT approached significance (p<0.08) for the whole tumor and was significant for all 3 sub-regions (p=0.03 to 0.004). A relationship between tumor size and DCE-CT parameters was not demonstrated.
Conclusion: This study suggests mean tumor blood volume as calculated with DCE-CT may be able to stratify patients by nodal status. Further studies are required to determine if this can be used to stratify patients with smaller size tumors who are surgical candidates into those with and without nodal metastases.
Questions about this event email: m.haider@utoronto.ca
Haider MD, M,
CT Perfusion as a Predictor of Nodal Status in Cervix Cancer. Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL.
http://archive.rsna.org/2003/3105655.html
