Vurthaluru Seenu

Longitudinal study of the assessment by MRI and diffusion-weighted imaging of tumor response in patients with locally advanced breast cancer undergoing neoadjuvant chemotherapy.

Measurements of tumor apparent diffusion coefficient (ADC), volume and diameter in assessing the response of patients with locally advanced breast cancer (LABC) (n = 56) undergoing neoadjuvant chemotherapy (NACT) at four time periods (before treatment and after three cycles of NACT) were carried out at 1.5 T using diffusion‐weighted imaging (DWI) and MRI. Ten benign tumors and 15 controls were also investigated. The MR tumor response was compared with the clinical response. Mean ADC before treatment of malignant breast tissue was significantly lower than that of controls, disease‐free contralateral tissue of the patients, and benign lesions, and gradually increased during the course of NACT. Analysis of the percentage change in ADC, volume and diameter after each cycle of NACT between clinical responders and non‐responders showed that the change in ADC after the first cycle was statistically significant compared with volume and diameter, indicating its potential in assessing early response. After the third cycle, the sensitivity for differentiating responders from non‐responders was 89% for volume and diameter and 68% for ADC, and the respective specificities were 50%, 70% and 100%. A sensitivity of 84% (specificity of 60% with an accuracy of 76%) was achieved when all three variables were taken together to predict the response. A cut‐off value of ADC was also calculated using receiver operator characteristics analysis to discriminate between normal, benign and malignant breast tissue. Similarly, a cut‐off value for ADC, volume and diameter was obtained after the second and third cycles of NACT to predict tumor response. The results show that ADC is more useful for predicting early tumor response to NACT than morphological variables, suggesting its potential in effective treatment management. Copyright

Monitoring the therapeutic response of locally advanced breast cancer patients: Sequential in vivo proton MR spectroscopy study

To evaluate the use of the water‐to‐fat (W‐F) value obtained from in vivo proton (1H) MR spectroscopy (MRS) as a response indicator of cytologically confirmed patients with locally advanced breast cancer (LABC), and to monitor the therapeutic response of such patients to neoadjuvant chemotherapy (NACT)

Assessment of therapeutic response of locally advanced breast cancer (LABC) patients undergoing neoadjuvant chemotherapy (NACT) monitored using sequential magnetic resonance spectroscopic imaging (MRSI).

The potential of total choline (tCho) signal‐to‐noise ratio (SNR) (ChoSNR) and tumor volume in the assessment of tumor response in locally advanced breast cancer (LABC) patients (n = 30) undergoing neoadjuvant chemotherapy (NACT) was investigated using magnetic resonance spectroscopic imaging (MRSI) and conventional MRI at 1.5 T. Experiments were carried out sequentially at four time‐points: prior to therapy and after I, II and III NACT and ChoSNR, and the tumor volume was measured. The MR response was compared with the clinical response. Sequential data of 25 patients were retrospectively analyzed by classifying them as clinical responders and non‐responders. In 14 responders, the pre‐therapy ChoSNR was 7.8 ± 5.1. In 10/14 responders, no choline was observed after III NACT while in the remaining four patients the ChoSNR was reduced to 3.6 ± 1.1 (p < 0.05). Non‐responders showed no statistically significant change in ChoSNR. After III NACT, the tumor volume reduced by 84.0 ± 14.8% in responders. Using receiver operating curve (ROC) analysis, cut‐off values of 53% for ChoSNR and 47.5% for volume were obtained to differentiate responders from non‐responders. The sensitivity to detect responders from non‐responders using ChoSNR was 85.7% with 91% specificity while 100% sensitivity was observed for volume but with reduced specificity of 73%. Our results indicate that ChoSNR may serve as a useful parameter to predict tumor response to NACT with higher specificity compared to volume, suggesting its potential in effective treatment management. Copyright

Association of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 status with total choline concentration and tumor volume in breast cancer patients: An MRI and in vivo proton MRS study

The association of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2) status of breast cancer patients with total choline (tCho) concentration and tumor volume was investigated using in vivo proton magnetic resonance spectroscopy and MRI at 1.5 T. Values for tCho concentration were determined in 120 locally advanced breast cancer patients (stages IIB, IIIA, IIIB, and IIIC), 31 early breast cancer patients (stage IIA), 38 patients with benign lesions, and 37 controls. Significantly higher tCho concentration and lower tumor volume were observed in early breast cancer patients compared to locally advanced breast cancer patients (P < 0.05). tCho concentration and tumor volume did not correlate with age and menstruation. tCho cutoff values were obtained for the differentiation of malignant from benign breast tissues (2.54 mmol/kg); malignant versus normal (1.45 mmol/kg) and benign versus normal tissues (0.82 mmol/kg). Estrogen receptor negative patients showed significantly larger tumor volumes, indicating higher angiogenesis with aggressive tumor behavior. Nontriple negative and triple positive patients had a significantly higher tCho concentration compared to triple negative patients (P < 0.05), indicating complex molecular mechanism of cell proliferation and the molecular heterogeneity of breast lesions. The results indicate the potential use of integration of breast 1H magnetic resonance spectroscopy in diagnostic workup. Magn Reson Med, 2012.

Role of apparent diffusion coefficient values for the differentiation of viable and necrotic areas of breast cancer and its potential utility to guide voxel positioning for MRS in the absence of dynamic contrast-enhanced MRI data

We carried out retrospective analysis of apparent diffusion coefficient (ADC) values in 48 infiltrating ductal breast cancer patients who had dynamic contrast-enhanced magnetic resonance imaging (DCEMRI; Group I) and in 53 patients (Group II) for whom DCEMRI data were not available. Twenty-three patients of Group I showed no necrosis (Group Ia), while in 25 patients, both viable (nonnecrotic) and necrotic tumor areas (Group Ib) were observed on DCEMRI. T1-weighted, fat-suppressed and short inversion recovery images were used to identify the viable and necrotic tumor areas in Group II patients, and necrosis was not seen in 11 patients (Group IIa), while 42 (Group IIb) showed both viable and necrotic tumor areas. The ADCs of the necrotic area of Group Ib (1.79±0.30 ×10(-3) mm(2)/s) and Group IIb (1.83±0.40 ×10(-3) mm(2)/s) patients were similar and significantly higher (P<.01) compared to the ADCs of the viable tumor area of Group Ia (0.96±0.21 ×10(-3) mm(2)/s) and Group IIa (0.90±0.17 ×10(-3) mm(2)/s) patients. Proton MR spectroscopy (MRS) data were also available in these patients, and the ADC values were retrospectively determined from the voxel from which MR spectrum was obtained. These values were compared with the ADC obtained for the viable and necrotic areas of the tumor. ADC of the MRS voxel was similar to that obtained for the viable tumor area in patients of both groups. This interesting observation reveals the potential utility of using ADC values to identify viable tumor area for positioning of voxel for MRS in the absence of DCEMRI data.

Potential of Diffusion-Weighted Imaging in the Characterization of Malignant, Benign, and Healthy Breast Tissues and Molecular Subtypes of Breast Cancer

The role of apparent diffusion coefficient (ADC) in the diagnosis of breast cancer and its association with molecular biomarkers was investigated in 259 patients with breast cancer, 67 with benign pathology, and 54 healthy volunteers using diffusion-weighted imaging (DWI) at 1.5 T. In 59 breast cancer patients, dynamic contrast-enhanced MRI (DCEMRI) was also acquired. Mean ADC of malignant lesions was significantly lower (1.02 ± 0.17 × 10−3 mm2/s) compared to benign (1.57 ± 0.26 × 10−3 mm2/s) and healthy (1.78 ± 0.13 × 10−3 mm2/s) breast tissues. A cutoff ADC value of 1.23 × 10−3 mm2/s (sensitivity 92.5%; specificity 91.1%; area under the curve 0.96) to differentiate malignant from benign diseases was arrived by receiver operating curve analysis. In 10/59 breast cancer patients, indeterminate DCE curve was seen, while their ADC value was indicative of malignancy, implying the potential of the addition of DWI in increasing the specificity of DCEMRI data. Further, the association of ADC with tumor volume, stage, hormonal receptors [estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor (HER2)], and menopausal status was investigated. A significant difference was seen in tumor volume between breast cancer patients of stages IIA and IIIA, IIB and IIIA, and IIB and III (B + C), respectively (P < 0.05). Patients with early breast cancer (n = 52) had significantly lower ADC and tumor volume than those with locally advanced breast cancer (n = 207). No association was found in ADC and tumor volume with the menopausal status. Breast cancers with ER−, PR−, and triple-negative (TN) status showed a significantly larger tumor volume compared to ER+, PR+, and non-triple-negative (nTN) cancers, respectively. Also, TN tumors showed a significantly higher ADC compared to ER+, PR+, and nTN cancers. Patients with ER− and TN cancers were younger than those with ER+ and nTN cancers. The present study demonstrated that ADC may increase the diagnostic specificity of DCEMRI and be useful for treatment management in clinical setting. Additionally, it provides an insight into characterization of molecular types of breast cancer and may serve as an indicator of metabolic reprograming underlying tumor proliferation.

Characterization of malignant breast tissue of breast cancer patients and the normal breast tissue of healthy lactating women volunteers using diffusion MRI and in vivo 1H MR spectroscopy.

To investigate the potential of diffusion weighted imaging (DWI) and in vivo proton MR spectroscopy (MRS) in the differentiation of breast tissue of healthy lactating women volunteers and breast cancer patients.

Pre-operative assessment of residual disease in locally advanced breast cancer patients: A sequential study by quantitative diffusion weighted MRI as a function of therapy

PURPOSE The potential of diffusion weighted imaging (DWI) in assessing pathologic response and surgical margins in locally advanced breast cancer patients (n=38) undergoing neoadjuvant chemotherapy was investigated. METHODS DWI was performed at pre-therapy (Tp0), after I (Tp1) and III (Tp3) NACT at 1.5T. Apparent diffusion coefficient (ADC) of whole tumor (ADCWT), solid tumor (ADCST), intra-tumoral necrosis (ADCNec) was determined. Further, ADC of 6 consecutive shells (5mm thickness each) including tumor margin to outside tumor margins (OM1 to OM5) was calculated and the data analyzed to define surgical margins. RESULTS Of 38 patients, 6 were pathological complete responders (pCR), 19 partial responders (pPR) and 13 were non-responders (pNR). Significant increase was observed in ADCST and ADCWT in pCR and pPR following therapy. Pre-therapy ADC was significantly lower in pCR compared to pPR and pNR indicating the heterogeneous nature of tumor which may affect drug perfusion and consequently the response. ADC of outside margins (OM1, OM2, and OM3) was significantly different among pCR, pPR and pNR at Tp3 which may serve as response predictive parameter. Further, at Tp3, ADC of outside margins (OM1, OM2, and OM3) was significantly lower compared to that seen at Tp0 in pCR, indicating the presence of residual disease in these shells. CONCLUSION Pre-surgery information may serve as a guide to define cancer free margins and the extent of residual disease which may be useful in planning breast conservation surgery.

Study of lipid metabolism by estimating the fat fraction in different breast tissues and in various breast tumor sub-types by in vivo 1 H MR spectroscopy

PURPOSE To evaluate the utility of fat fraction (FF) for the differentiation of different breast tissues and in various breast tumor subtypes using in vivo proton (1H) magnetic resonance spectroscopy (MRS). METHODS 1H MRS was performed on 68 malignant, 35 benign, and 30 healthy volunteers at 1.5 T. Malignant breast tissues of patients were characterized into different subtypes based on the differences in the expression of hormone receptors and the FF was calculated. Further, the sensitivity and specificity of FF to differentiate malignant from benign and from normal breast tissues of healthy volunteers was determined using receiver operator curve (ROC) analysis. RESULTS A significantly lower FF of malignant (median 0.12; range 0.01-0.70) compared to benign lesions (median 0.28; range 0.02-0.71) and normal breast tissue of healthy volunteers (median 0.39; range 0.06-0.76) was observed. No significant difference in FF was seen between benign lesions and normal breast tissues of healthy volunteers. Sensitivity and specificity of 75% and 68.6%, respectively was obtained to differentiate malignant from benign lesions. For the differentiation of malignant from healthy breast tissues, 76% sensitivity and 74.5% specificity was achieved. Higher FF was seen in patients with ER-/PR- status as compared to ER+/PR+ patients. Similarly, FF of HER2neu+ tumors were significantly higher than in HER2neu- breast tumors. CONCLUSION The results showed the potential of in vivo 1H MRS in providing insight into the changes in the fat content of different types of breast tissues and in various breast tumor subtypes.

Is there an association between enhanced choline and β-catenin pathway in breast cancer? A pilot study by MR Spectroscopy and ELISA

Total choline (tCho) was documented as a biomarker for breast cancer diagnosis by in vivo MRS. To understand the molecular mechanisms behind elevated tCho in breast cancer, an association of tCho with β-catenin and cyclin D1 was evaluated. Hundred fractions from 20 malignant, 10 benign and 20 non-involved breast tissues were isolated. Cytosolic and nuclear expressions of β-catenin and cyclin D1 were estimated using ELISA. Higher tCho was seen in malignant compared to benign tissues. Malignant tissues showed higher cytosolic and nuclear β-catenin expressions than benign and non-involved tissues. Within malignant tissues, β-catenin and cyclin D1 expressions were higher in the nucleus than cytosol. Cyclin D1 expression was higher in the cytosolic fractions of benign and non-involved than malignant tissues. Furthermore, in malignant tissues, tCho showed a positive correlation with the cytosolic and nuclear expression of β-catenin and cyclin D1 and also a correlation between nuclear expressions of both these proteins was seen. Higher cytosolic β-catenin expression was seen in progesterone receptor negative than positive patients. Results provide an evidence of correlation between non-invasive biomarker, tCho and the Wnt/β-catenin pathway. The findings explain the molecular mechanism of tCho elevation which may facilitate exploration of additional therapeutic targets for breast cancer.