Predicting breast cancer response to neoadjuvant treatment using multi-feature MRI: results from the I-SPY 2 TRIAL.

Dynamic contrast-enhanced (DCE) MRI provides both morphological and functional information regarding breast tumor response to neoadjuvant chemotherapy (NAC). The purpose of this retrospective study is to test if prediction models combining multiple MRI features outperform models with single features. Four features were quantitatively calculated in each MRI exam: functional tumor volume, longest diameter, sphericity, and contralateral background parenchymal enhancement. Logistic regression analysis was used to study the relationship between MRI variables and pathologic complete response (pCR). Predictive performance was estimated using the area under the receiver operating characteristic curve (AUC). The full cohort was stratified by hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status (positive or negative). A total of 384 patients (median age: 49 y/o) were included. Results showed analysis with combined features achieved higher AUCs than analysis with any feature alone. AUCs estimated for the combined versus highest AUCs among single features were 0.81 (95% confidence interval [CI]: 0.76, 0.86) versus 0.79 (95% CI: 0.73, 0.85) in the full cohort, 0.83 (95% CI: 0.77, 0.92) versus 0.73 (95% CI: 0.61, 0.84) in HR-positive/HER2-negative, 0.88 (95% CI: 0.79, 0.97) versus 0.78 (95% CI: 0.63, 0.89) in HR-positive/HER2-positive, 0.83 (95% CI not available) versus 0.75 (95% CI: 0.46, 0.81) in HR-negative/HER2-positive, and 0.82 (95% CI: 0.74, 0.91) versus 0.75 (95% CI: 0.64, 0.83) in triple negatives. Multi-feature MRI analysis improved pCR prediction over analysis of any individual feature that we examined. Additionally, the improvements in prediction were more notable when analysis was conducted according to cancer subtype

Benign Renal Schwannoma Radiology Case Reports Benign Renal Schwannoma

Schwannomas are tumors arising from cells of the nerve sheath. While schwannomas are commonly found in peripheral nerves and cranial nerves, these tumors are rarely found within the kidney and may be difficult to differentiate from renal cell carcinoma. Few cases have been reported in the literature, and very little has been described regarding the imaging appearance of these rare renal tumors. We present a case of intrarenal schwannoma with sonographic, computed tomographic, and pathologic correlation

Diffusion weighted imaging evaluated the early therapy effect of tamoxifen in an MNU-induced mammary cancer rat model.

To assess the optimal time point of diffusion-weighted imaging (DWI) for early prognosis of breast cancer following tamoxifen therapy using a methylnitrosourea (MNU)-induced ER-positive breast-cancer model.Two groups of Sprague-Dawley rats (n = 15 for group 1; n = 10 for group 2) were used. All animals (50 days old) were intravenously injected with MNU (50 mg/kg body weight) to induce ER-positive mammary tumors. When tumors were approximately 2 cm in diameter, DWI was performed on days 0, 3, and 7, and intratumoral apparent diffusion coefficient (ADC) values were measured. Therapy started on day 0 with tamoxifen (10 mg/kg diet) and continued for 4 weeks for group 1, but only 1 week for group 2, while tumor volume was measured by caliper twice weekly. All animals of group 2 were euthanized on day 7 after imaging, and Ki-67, TUNEL, ERα, and ERβ staining were performed on tumor tissue.DW images of MNU-induced mammary tumors were successfully obtained with minimal motion artifact. For group 1, ADC change for 3 days after therapy initiation (ADC3D) was significantly correlated with tumor-volume change until day 11, but the significant correlation between ADC change for 7 days (ADC7D) and the tumor-volume change was observed until day 18. Similarly, for group 2, either ADC7D or ADC3D was significantly correlated with the tumor-volume change, but the higher significance was observed for ADC7D. Furthermore, ADC7D was significantly correlated with apoptotic (TUNEL stained), proliferative (Ki-67 stained), and ERβ-positive cell densities, but ADC3D was not significantly correlated with any of those.ADC7D might be a more reliable surrogate imaging biomarker than ADC3D to assess effectiveness of tamoxifen therapy for ER-positive breast cancer, which may enable personalized treatment. The significant correlation between ADC7D and ERβ-positive cell density suggests that ERβ may play an important role as a therapeutic indicator of tamoxifen

Tumor volume and ADC changes following tamoxifen therapy.

<p>(A) Volume changes of tumors sensitive, intermediate, or resistant to tamoxifen over 32 days after therapy initiation, when the initial tumor volumes were normalized to 100%. (B) ADC changes of sensitive, intermediate, or resistant tumors for 7 days after therapy initiation, when the initial ADC values were normalized to 0%. Statistical differences from resistant and intermediate groups are represented with asterisk and hash mark, respectively.</p

Histological analysis of tumor response following tamoxifen therapy.

<p>(A) Representative microphotographs of tamoxifen sensitive, intermediate, and resistant tumor tissues with TUNEL, Ki-67, ERα, and ERβ staining, while the target cells were indicated with black arrows. (B) Apoptotic (TUNEL), (C) proliferative (Ki-67), (D) ERα-positive, and (E) ERβ-positive cell densities of the three groups. Statistical difference from resistant group is represented with asterisks above bars.</p

<i>p</i> values presenting the statistical correlation between tumor volume and ADC changes during 3∼32 days after therapy initiation (<i>r</i> values are inserted in parenthesis).

<p><i>p</i> values presenting the statistical correlation between tumor volume and ADC changes during 3∼32 days after therapy initiation (<i>r</i> values are inserted in parenthesis).</p

Illustration of animal positioning for DWI.

<p>(A) Lateral and (B) ventral views of an animal with a mammary tumor. Two plastic bars were used to lift up the tumor to minimize motion artifact. Wedges were represented with dark blue.</p