Transcript Slide 1
Philip Wong Department of Medical Biophysics University of Western Ontario March 23, 2011 Acknowledgments Dr. Gelman Fang Liu Dr. MacDonald Introduction Breast cancer is a cancer that is found in the tissues of the breast Most common cancer among women Detected by the presence of a breast tumor Malignant Benign Diagnosis Accuracy of the diagnostic method used to differentiate between benign and malignant tumors is important Dynamic contrast enhanced-MRI (DCE-MRI) “Hot spots” refers to areas within the tumor where the contrast agent is rapidly taken up (3 minutes) Motivation and Objective Provide an objective means of diagnosis Non-fibroadenoma (NF) (benign) and malignant tumors were not easily distinguished Compare spatial distribution of hot spots in NF and malignant tumors Approach Developed a code in MATLAB to calculate hot spot volumes in the outer perimeter of the tumors Statistical analysis (Mann-Whitney test) Hypothesis Malignant tumors will have a greater hot spot volume in the outer perimeter than NF tumors Methods Tumor Mask Matrix Methods Tumor Mask Matrix after one erosion Methods Hot Spot Mask Matrix Methods Hot Spot Mask Matrix from eroded tumor Methods Repeated this process for 16 NF tumors and 20 malignant tumors Defined outer perimeter as 25% of tumor volume Linear interpolation to find outer hot spot volume (OHS) (hot spot in outer perimeter) Methods Expressed OHS as a fraction of total tumor volume Ran a Mann-Whitney test to compare the fractional OHS of NF and malignant tumors Compared fractional OHS with fractional total hot spot volume (THS) Fractional Outer Hot Spot Volume Results p = 0.3477 (p > 0.05) n =16 n =20 Tumor Type Results Fractional OHS and THS Non-fibroadenoma: p = 0.0035 Malignant: p = 0.000011 Discussion No significant difference between the OHS of NF and malignant tumors Suggests that NF tumors behave similarly to malignant tumors in terms of their vasculature Significant difference between OHS and THS in both NF and malignant tumors Implies that most of hot spot volume is still located in the center of the tumor Future Work Observe effects of different thresholds and outer perimeters Examine why NF are similar to malignant tumors Run Mann-Whitney test between a nonfibroadenoma subgroup and malignant tumors Conclusion No significant difference in spatial distribution of hot spots between NF and malignant tumors Significant difference between OHS and THS in both NF and malignant tumors Questions?