The usage of diffusion weighted mr images and adc values in evaluating the response to the treatment in local advanced breast cancer

Introduction and Purpose To analyse the patient with breast cancer, after the neoadjuvant chemotherapy using diffusion weighted magnetic resonance imaging (MRI) and to determine the values of ADC (apparent diffusion imaging), to evaluate the contribution of diffusion weighted magnetic resonance imaging and ADC, in evaluating the response of lesion to chemotherapy in early period. Material and method Twenty four woman patients, aged between 27?77 (average:50,5) who had histopathologically diagnosed as breast cancer were included in our study. Magnetic resonance imaging was done selective to breast, using a MR device with 1,5 tesla magnetic field power. After that diffusion weighted images were taken by spin echo `echo planar imaging? sequence to both two breast. The `b? value was determined as 0 and 550 mm²/sn in the study. From the images that were acquired, the ADC values determined in fibroglandulary tissue, which belongs to the normal breast parenchyma, and in breast lesions. In second phase, 13 patients who had neoadjuvant chemotheraphy were included in evaluation. The examinations repeated after second cure of chemotheraphy for all patients and compared with ADC values before treatment. Also, central and peripheric scales evaluated among themselves before the theraphy and after the theraphy. The tumors which denoted central necrotic areas because of theraphy were noted. The ADC values, acquired from each lesion?s central and peripheric areas, were compared among themselves and compared to contralateral breast. The scales which were measured from ADC maps acquired from diffusion weighted images after the treatment and the scales measured before the treatment were compared and evaluated if they are competible with the response determined by RECIST scales or not. According to the tumors pathological types, it was evaluated if there?s a meaningful difference between before and after treatment ADC values or not. Finally, the ADC values determined after theraphy which belongs to normal breast tissue that has no lesions, compared to the ADC values before the theraphy and the affects of chemothrapeutic agents to normal breast parenchyma were investigated. Results All of 24 patients included in the study had diagnosed histopathologically as breast cancer. In measurements made in malign lesions the ADC values mean average was found as 1,07 x 10?³ mm²/sn, the treshold value was found as 1,48 x 10?³ mm²/sn. In glandulary tissue of contralateral breast the ADC values mean average was found as 1,80x 10?³ mm²/sn. The ADC values of malign lesions were statistically meaningful lower then normal glandulary tissue ADC values (Mann Whitney U test, p < 0.001). After, the ADC values before the treatment and after the treatment were compared in 13 patients who had neoadjuvant chemotherapy. In tumors which had necrotic area before the treatment, the ADC values were higher in central then periphery. The number of tumors which had necrotic area was increased after the treatment. The ADC values mean averages after treatment (1,38 x 10?³ mm²/sn) were found statistically meaningful higher then the ADC values mean average before the treatment (1,06 x 10?³ mm²/sn) (Wilcoxon test, p = 0.003). In only one case which had given minimal response to treatment (invasive lobulary carsinoma), no increase in ADC values after treatment were seen. In statistical evoluation made to value the affects of chemotherapeutics to normal breast parenchyma, there were no statistically difference between ADC values of two breasts before the treatment and the ADC values after the treatment.(Wilcoxon test, p = 0.658 and p = 0.702). Conclusion In breast cancer, the cellular density decreases, the diffusion limitation decreases as a result of degeneration in cellular membrane structure and the ADC values increase after the threatment. According to that, it was shown that the response to treatment after chemotheraphy can be evaluated by diffusion weighted images in early period.