Spatial Distribution of Hot Spots in Breast
TumorsPhilip Wong
Department of Medical Biophysics
University of Western Ontario
March 23, 2011
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 tumorMalignant 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 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)
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 non-fibroadenoma 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