4th International Istanbul Breast Cancer Virtual Conference, İstanbul, Turkey, 17 - 18 October 2020, pp.53
Diffusion of water molecules is restricted in malignant breast lesions due to cellular proliferation. It is possible to quantify diffusion restriction by ADC maps in diffusion weighted magnetic resonance imaging (MRI). Ki67 is a proliferation index which is closely associated with tumour growth rate and prognosis. High Ki67 values can lead oncologists to recommend neoadjuvant chemotherapy, but they are usually determined from biopsy material, which may or may not represent whole histology. The purpose of this study was to compare ADC and Ki67 values in order to search for a correlation, which can give a clue about proliferation and prognosis at the time of diagnosis and help determine appropriate therapy. MATERIALS-METHODS:
Consecutive 30 patients with breast cancer who had undergone breast MRI followed by surgery between April 2020 and August 2020 were retrospectively evaluated. All MRI examinations were performed with 1.5T machine (Siemens Avanto Fit). Diffusion weighted imaging was performed using EPI sequence (b values 0 and 800). Ki 67 values were determined by digital pathological evaluation from surgical specimens. ADC values were determined from ADC maps by placing a ROI that matched the size of the tumour, without including surrounding benign breast tissue. Three measurements were made from each mass and minimum, maximum and mean ADC values were recorded. Average mean ADC and Ki67 values were correlated using Pearson correlation and student-t tests. RESULTS:
Mean ADC values ranged between 0.037 and 1.448. Ki67 values ranged between %1 and %80. There was no statistically significant correlation (Pearson correlation score=%19.6, p=0.299). Cut-off value of 20 was chosen to group Ki67 values as low or high and t-test was used to correlate with ADC values, which again revealed no significant correlation (p=0.331). CONCLUSION:
We found no significant correlation between mean ADC and Ki67 values in this study. This may be due to the low number of cases and wide range of ADC and Ki67 values in this small group. There are varying results in literature on this topic. We will continue our study with a larger number of cases including minimum ADC values in comparison.
Keywords: Diffusion MRI, ADC value