Changes in the findings of dynamic MRI by preoperative CAF chemotherapy for patients with breast cancer of stage II and III: pathologic correlation

Serial Assessment of Therapeutic Response to a New Radiosensitization Treatment, Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas, Type II (KORTUC II), in Patients with Stage I/II Breast Cancer Using Breast Contrast-Enhanced Magnetic Resonance Imaging

Background: We have developed a new radiosensitization treatment called Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas, Type II (KORTUC II). Using KORTUC II, we performed breast-conserving treatment (BCT) without any surgical procedure for elderly patients with breast cancer in stages I/II or patients refusing surgery. Since surgery was not performed, histological confirmation of the primary tumor region following KORTUC II treatment was not possible. Therefore, to precisely evaluate the response to this new therapy, a detailed diagnostic procedure is needed. The goal of this study was to evaluate the therapeutic response to KORTUC II treatment in patients with stage I/II breast cancer using annual breast contrast-enhanced (CE) magnetic resonance imaging (MRI). Methods: Twenty-one patients with stage I/II breast cancer who were elderly and/or refused surgery were enrolled in this study. All patients underwent MRI prior to and at 3 to 6 months after KORTUC II, and then approximately biannually thereafter. Findings from MRI were compared with those from other diagnostic modalities performed during the same time period. Results: KORTUC II was well tolerated, with minimal adverse effects. All of 21 patients showed a clinically complete response (cCR) on CE MRI. The mean period taken to confirm cCR on the breast CE MRI was approximately 14 months. The mean follow-up period for the patients was 61.9 months at the end of October 2014. Conclusions: The therapeutic effect of BCT using KORTUC II without surgery could be evaluated by biannual CE MRI evaluations. Approximately 14 months were required to achieve cCR in response to this therapy.

Review of electromagnetic techniques for breast cancer detection

Breast cancer is anticipated to be responsible for almost 40,000 deaths in the USA in 2011. The current clinical detection techniques suffer from limitations which motivated researchers to investigate alternative modalities for the early detection of breast cancer. This paper focuses on reviewing the main electromagnetic techniques for breast cancer detection. More specifically, this work reviews the cutting edge research in microwave imaging, electrical impedance tomography, diffuse optical tomography, microwave radiometry, biomagnetic detection, biopotential detection, and magnetic resonance imaging (MRI). The goal of this paper is to provide biomedical researchers with an in-depth review that includes all main electromagnetic techniques in the literature and the latest progress in each of these techniques.

Diffuse Optical Monitoring of the Neoadjuvant Breast Cancer Therapy

Recent advances in the use of diffuse optical techniques for monitoring the hemodynamic, metabolic and physiological signatures of the neoadjuvant breast cancer therapy effectiveness is critically reviewed. An extensive discussion of the state-of-theart diffuse optical mammography is presented alongside a discussion of the current approaches to breast cancer therapies. Overall, the diffuse optics field is growing rapidly with a great deal of promise to fill an important niche in the current approaches to monitor, predict and personalize neoadjuvant breast cancer therapies.

Non-surgical therapy and radiologic assessment of stage I breast cancer treatment with novel enzyme-targeting radiosensitization: Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas, type II (KORTUC II)

The new enzyme-targeting radiosensitization treatment, Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas, type II (KORTUC II), markedly enhances the radiotherapeutic effect of treatment for various types of locally advanced malignant neoplasms. Patients who had declined surgical treatment and systemic chemotherapy, as well as a total of 14 stage I breast cancer patients, were enrolled. A maximum of 6 ml of KORTUC II was injected into tumor tissue twice a week under ultrasonographic guidance, immediately prior to each administration of radiation therapy. The median observation period was 21.6 months with a range of 4-48 months, and the therapy was well tolerated. Contrast-enhanced magnetic resonance imaging and [(18)F]-fluorodeoxyglucose positron emission computed tomography revealed that all primary breast tumors completely responded, and none of the subjects experienced local recurrence during the observation period. Ultrasonography depicted tumor-like findings in 2/14 cases after therapy. The intratumoral flow signal on color-Doppler sonography was positive in 4/14 cases before therapy, and the signal disappeared from all cases after therapy. The absence of a flow signal after therapy suggested that the tumor-like findings on ultrasonography were from scar tissue. Excellent local control based on accurate radiological evaluation implies that KORTUC II has the potential to replace surgery as a therapeutic option for stage I breast cancer. Precise evaluation by various radiological modalities helped to gage the success of this therapy.

Diffusion-weighted magnetic resonance imaging for assessment after neoadjuvant chemotherapy in breast cancer, based on morphological concepts

The study aimed to evaluate the utility of diffusion-weighted imaging (DWI) and to assess the response of breast cancer patients to neoadjuvant chemotherapy (NAC), based on morphological concepts. This retrospective study included 35 breast cancer patients (36 lesions) who had conventional magnetic resonance imaging (MRI), with DWI acquired before and after NAC. The morphological pattern of delayed enhancement on MRI before NAC was classified into two types: focal mass (FM), and multiple masses and/or non-mass like (MM/NM), based on Breast Imaging Reporting and Data System (BI-RADS). Of the 36 tumors, 26 were classified as FM and 10 as MM/NM. Tumors were clearly visualized on the initial DWI although one case of suspected MM/NM was not observed on DWI following NAC. A correlation was found between changes in the apparent diffusion coefficient and response rates to NAC in FM tumors (r=0.608, p<0.001), but not in MM/NM tumors (r=0.141, p=0.717). There was agreement between MRI findings after NAC and pathological findings in 30 of the 36 tumors (83.3%). Thus, we concluded that DWI is potentially useful in assessing the response to NAC for breast cancer for tumors diagnosed as FM on the initial conventional MRI.

Current Status of Breast MR Imaging Part 2. Clinical Applications

Magnetic resonance (MR) imaging is emerging as the most sensitive modality that is currently available for the detection of primary or recurrent breast cancer. Although this technique has been shown to be an extremely powerful diagnostic tool, it is still relatively rarely used in clinical practice, as compared with other applications of MR imaging such as for musculoskeletal or brain and spine imaging. This is the second of a two-part series on the current status of breast MR. Part two provides an overview of the use of breast MR imaging in clinical patient care, the body of evidence that supports its use. A discussion is provided on the many controversies that exist regarding breast MR imaging for preoperative staging and for screening.

Influence of post-treatment delay on the evaluation of the response to focused ultrasound surgery of breast cancer by dynamic contrast enhanced MRI

The assessment of the effectiveness of MRI-guided focused ultrasound surgery (MRIgFUS) of breast carcinomas can be performed by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters which monitor the presence of residual tumour. The aim of this study was to evaluate the effect of the post-treatment delay on this assessment. DCE-MRI data were acquired immediately and 3-14 days after MRIgFUS treatment of 26 tumours (<7 days, n = 6; = or > ge;7 days, n = 20). The percentage of residual tumour was determined histologically on the resected mass and correlated with two DCE-MRI parameters: increase in signal intensity (ISI) and positive enhancement integral (PEI). No correlation could be found between DCE-MRI data acquired immediately after treatment and the percentage of residual tumour. Good correlation coefficients were found for data acquired several days after treatment (ISI, r = 0.749; PEI, r = 0.778). However, they were higher when the post-treatment time interval was 7 days or more (ISI, r = 0.962; PEI, r = 0.934). These results suggest that a post-treatment delay of 7 days is necessary for the accurate assessment of the presence of residual tumour by DCE-MRI parameters.

MR Quantification of the Washout Changes in Breast Tumors Under Preoperative Chemotherapy: Feasibility and Preliminary Results

OBJECTIVE

The objective of our study was to describe and determine the feasibility of an MR washout quantification method in patients with breast cancer under preoperative chemotherapy.

MATERIALS AND METHODS

Nineteen patients with breast T2 or T3 tumors were enrolled in a previous study for tumor response evaluation during chemotherapy based on dynamic contrast-enhanced MRI. We retrospectively used the dynamic acquisition data to produce parametric images representing the washout pattern. Two radiologists unaware of the final pathologic results measured the volume of pixels exhibiting washout within the tumor before chemotherapy (volume 1), after two courses of chemotherapy (volume 2), and before surgery after four courses of chemotherapy (volume 3). The interobserver variability and intraobserver variability were calculated to evaluate the reproducibility of our method with the Pearson's correlation coefficient and the concordance correlation coefficient. We correlated the washout changes by means of a Student's t test and noted the histopathologic final outcome.

RESULTS

A washout pattern was present in all patients on the initial MR study. The quantification method of the washout changes was reproducible with good interobserver agreement (r = 0.85, p < 10(-5)) and an excellent intraobserver agreement (r = 0.94, p < 10(-5)). A significant decrease of the washout volume was observed after two courses of chemotherapy (p = 0.004), whereas no significant modification was observed between two and four courses of chemotherapy (p = 0.52).

CONCLUSION

Quantification of the washout variation in breast tumor based on the use of parametric images is feasible and reproducible. It may add information to the evaluation of tumor response to preoperative therapy.

Can breast MRI help in the management of women with breast cancer treated by neoadjuvant chemotherapy?

Contrast-enhanced (CE) MRI was used to monitor breast cancer response to neoadjuvant chemotherapy. Patients underwent CE MRI before and after therapy, together with conventional assessment methods (CAM). CE MRI was carried out at 1.5 T in the coronal plain with 3D sequences before and after bolus injection. An expert panel determined chemotherapy response using both CE MRI and CAM. Histopathological response in the surgical specimen was then used to determine the sensitivity and specificity of CE MRI and CAM. In total, 67 patients with 69 breast cancers were studied (mean age of 46 years). Tumour characteristics showed a high-risk tumour population: median size 49 mm: histopathological grade 3 (55%): oestrogen receptor (ER) negative (48%). Histopathological response was as follows: – complete pathological response (pCR) 17%; partial response (pPR) 68%; no response (NR) 15%. Sensitivity of CAM for pCR or pPR was 98% (CI 91–100%) and specificity was 50% (CI 19–81%). CE MRI sensitivity was 100% (CI 94–100%), and specificity was 80% (CI 44–97%). The absolute agreement between assessment methods and histopathology was marginally higher for CE MRI than CAM (81 vs 68%; P=0.09). In 71%, CE MRI increased diagnostic knowledge, although in 20% it was judged confusing or incorrect. The 2nd MRI study significantly increased diagnostic confidence, and in 19% could have changed the treatment plan. CE MRI persistently underestimated minimal residual disease. In conclusion, CE MRI of breast cancer proved more reliable for predicting histopathological response to neoadjuvant chemotherapy than conventional assessment methods.

The use of contrast-enhanced computed tomography before neoadjuvant chemotherapy to identify patients likely to be treated safely with breast-conserving surgery

OBJECTIVE

To select suitable candidates for breast-conserving treatment (BCT) after neoadjuvant chemotherapy (NAC), based on the classification of tumors into localized or diffuse types using contrast-enhanced computed tomography (CE-CT).

SUMMARY BACKGROUND DATA

A relatively high rate of loco-regional failure after BCT has been reported with breast cancer downstaged by NAC. Accurate assessment of the suitability of BCT and the response to NAC, before the initiation of NAC, will allow the optimal selection of an appropriate therapeutic course.

METHODS

We evaluated 110 consecutive patients with operable breast carcinomas measuring 3-cm or more in diameter by CE-CT after NAC treatment with doxorubicin and docetaxel at National Cancer Center Hospital, Tokyo, from May 1998 to November 2001. Lesions were classified as either localized or diffuse types by mammography (MMG), ultrasonography (US), and CE-CT.

RESULTS

Tumors designated as localized type by MMG, US, and CE-CT were reduced to tumors less than 3.0 cm (P < 0.0001) in a concentric circle (P < 0.0001). Localized tumors by CE-CT were treated safely with BCT maintaining a negative margin status (P = 0.01). In contrast, diffuse type tumors shrunk into a mosaic pattern consisting of tumors larger than 3.1 cm. Tumors classified as localized by CE-CT responded better pathologically than diffuse tumors (P = 0.0365). Multivariate analysis demonstrated that morphologic type by CE-CT and histologic type were significant predictors of candidates for safe BCT.

CONCLUSIONS

The classification of tumors into either localized or diffuse types, using CE-CT before NAC administration, accurately predicts which tumors will be suitable candidates for BCT after NAC.

Preoperative breast cancer staging: MR imaging of the axilla with ultrasmall superparamagnetic iron oxide enhancement

PURPOSE

To evaluate magnetic resonance (MR) imaging with ultrasmall superparamagnetic iron oxide (USPIO) enhancement for preoperative axillary lymph node staging in patients with breast cancer by using histopathologic findings as the standard of reference.

MATERIALS AND METHODS

MR imaging was performed with a 1.5-T system within 24-36 hours after the start of intravenous slow-drip infusion of USPIO in 20 patients with breast cancer who were scheduled for surgery, followed by gadolinium-enhanced MR imaging. Lymph nodes were staged prospectively by using newly established criteria, and results were correlated with histologic findings.

RESULTS

In two patients, preoperative findings led to a change in therapeutic approach, and neoadjuvant chemotherapy was given; both patients were excluded from statistical analysis. Results of axillary staging with USPIO-enhanced MR imaging were true-positive in nine, true-negative in seven, false-positive in zero, and false-negative in two of 18 patients (sensitivity, 82%; specificity, 100%; positive predictive value, 100%; second reader, kappa = 1.0). Four hundred five lymph nodes were detected with MR imaging. For first and second readers, respectively, lymph node-based sensitivity was 83% and 73% and specificity was 96% and 97% (kappa = 0.68). USPIO as the intravascular contrast agent could not replace gadolinium for assessment of the primary tumor; however, no clinically relevant interaction was seen. Thus, an integrated imaging approach was feasible in all patients.

CONCLUSION

USPIO-enhanced MR imaging has the potential to become an adjunct to conventional MR imaging of the breast for preoperative assessment of axillary lymph nodes in patients with breast cancer.

Accuracy of MR imaging for revealing residual breast cancer in patients who have undergone neoadjuvant chemotherapy

OBJECTIVE

Our study investigated the usefulness of contrast-enhanced MR imaging for accurately measuring the size of residual tumor after patients have undergone neoadjuvant (pre-operative) chemotherapy. The imaging analysis method was optimized for identifying residual disease in the treated breast. Tumor sizes measured on the MR images and at the clinical examination were compared with the size of residual disease measured at pathology after surgery.

SUBJECTS AND METHODS

Before undergoing surgery, 52 patients were imaged before and after receiving neoadjuvant chemotherapy. For each patient, specific malignancy criteria were applied to MR images before chemotherapy to identify the location of tumor, and residual disease was then identified as any remaining enhancement in the same area on the MR images after chemotherapy. Residual tumor size was measured using both the MR technique and the clinical examination findings, and the degree of measurement error for each method was assessed in comparison with the pathologic findings.

RESULTS

The correlation with pathology was an r value of 0.89 for MR measurements compared with an r value of 0.60 for clinical measurements. In addition, MR imaging revealed all cases of residual disease, whereas clinical assessment resulted in five false-negative interpretations in the 52 treated lesions.

CONCLUSION

The high correlation between measurements of residual disease obtained on MR images and those obtained at pathology validates the sensitivity of MR imaging of the breast after chemotherapy.