Role of Breast MR Imaging in Neoadjuvant Chemotherapy
Neoadjuvant chemotherapy is now widely used in the management of locally advanced breast cancer (LABC). Early initiation of systemic therapy can improve overall and disease-free survival for patients with LABC or inflammatory cancer. MR imaging with intravenous contrast and advanced MR imaging techniques provide new opportunities for assessing tumor morphologic changes, tumor vascularity, tumor cellularity, and tumor metabolic features. MR imaging is more reliable than the conventional methods in the assessment of tumor size and vascularity changes during and after chemotherapy. The addition of advanced imaging techniques to further characterize tumor cellularity and metabolic features appears promising. However, there is still no consensus on the role of MR imaging for assessing response to neoadjuvant chemotherapy or on a standardized MR imaging examination in patients receiving neoadjuvant chemotherapy.
[Show abstract] [Hide abstract] ABSTRACT: Purpose . We performed this meta-analysis to determine the utilities of 18 F-FDG PET/CT and MRI in assessing the pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) in the same cohort of patients with breast cancer. Methods . Two reviewers systematically searched on PubMed, Scopus, and Springer (from the beginning of 1992 to Aug. 1, 2015) for the eligible articles. Heterogeneity, pooled sensitivity and specificity, positive likelihood ratio, negative likelihood ratio, and the summary receiver operating characteristic (SROC) curve were calculated to estimate the diagnostic efficacy of 18 F-FDG PET/CT and MRI. Results . A total of 6 studies including 382 pathologically confirmed patients were eligible. The pooled sensitivity and specificity of 18 F-FDG PET/CT were 0.86 (95% CI: 0.76–0.93) and 0.72 (95% CI: 0.49–0.87), respectively. Pooled sensitivity and specificity of MRI were 0.65 (95% CI: 0.45–0.80) and 0.88 (95% CI: 0.75–0.95), respectively. The area under the SROC curve of 18 F-FDG PET/CT and MRI was 0.88 and 0.84, respectively. Conclusion . Study indicated that 18 F-FDG PET/CT had a higher sensitivity and MRI had a higher specificity in assessing pCR in breast cancer patients. Therefore, the combined use of these two imaging modalities may have great potential to improve the diagnostic performance in assessing pCR after NAC.0Comments 0Citations
- "Magnetic resonance imaging (MRI) and 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) are increasingly being used to screen and monitor the response to NAC in breast cancer [6, 7]. In case of locally advanced breast cancer, MRI has the potential to select those patients that are eligible for conservative surgical treatment after NAC [8, 9]. In addition, as noted by Buchbender and colleagues, PET/MRI with lower radiation exposure and joining all the benefits of morphologic and functional MRI information and metabolic PET information may be most useful in setting of evaluation for suspected tumor recurrence, response to neoadjuvant therapy, and prognosis . "
[Show abstract] [Hide abstract] ABSTRACT: There is a strong need to assess early tumor response to chemotherapy in order to avoid adverse effects from unnecessary chemotherapy and allow early transition to second-line therapy. This study was to quantify tumor perfusion changes with dynamic contrast-enhanced ultrasound (CEUS) in the evaluation of early tumor response to cytotoxic chemotherapy. Sixty nude mice bearing with MCF-7 breast cancer were administrated with either adriamycin or sterile saline. CEUS was performed on days 0, 2, 4 and 6 of the treatment, in which time-signal intensity (SI) curves were obtained from the intratumoral and depth-matched liver parenchyma. Four perfusion parameters including peak enhancement (PE), area under the curve of wash-in (WiAUC), wash-in rate (WiR) and wash-in perfusion index (WiPI) were calculated from perfusion curves and normalized with respect to perfusion of adjacent liver parenchyma. Histopathological analysis was conducted to evaluate tumor perfusion, tumor cell density, microvascular density (MVD) and proliferating cell density. Significant decreases of tumor normalized perfusion parameters (i.e., nPE, nWiAUC, nWiR and nWiPI) were noticed between adriamycin-treated and control groups (<0.01) 2 days after therapy. There were significant differences of tumor volumes between control and treated groups on day 6 (<0.001) while there were no significant differences in tumor volume on days 0, 2 and 4 (>0.05). Significant decreases of tumor perfusion, tumor cell density, MVD and proliferating cell density were seen in adrianycin-treated group 2 days after therapy when compared to control group (<0.001). Dynamic CEUS for quantification of tumor perfusion could be used for early detection of cancer response to cytotoxic chemotherapy prior to notable tumor shrinkage.0Comments 6Citations
- "The extent of FDG uptake by lesions smaller than twice the quoted resolution of PET is often underestimated . Both DCE-MRI and DCE-CT have shown potentials as functional imaging tools to early assess tumor response to chemotherapy by detecting tumor blood perfusion changes , –. Although DCE-MRI offers relatively good sensitivity and spatial resolution in soft tissue imaging, the spatial resolution must be traded off to get a sufficient frame rate for dynamic tracking of the contrast agent in order to perform whole organ scans with functional imaging information . "
- [Show abstract] [Hide abstract] ABSTRACT: The use of color vision as a tool for machine vision provides a powerful means of performing rapid, accurate inspection of microelectronic structures. Since microelectronics fabrication is in large part a thin film technology, and since thin films have characteristic colors, this approach extends the range of optical analysis possible. We have constructed a color vision system used to measure thin film dielectric materials. Color matching is performed rapidly (<100 msecs) and with resolution better than 20 Å. The resolution limit has been so far set only by the samples available for measurement. We have further extended the capability of the system beyond simple color matching to identify true unknown samples whose thickness fall within the range of the original system database. Feed-back control of the illumination has been incorporated into the system; we present data on the effect of shifts in lighting or magnification. Microscopic, as well as broad area measurements (for uniformity) can be made.0Comments 13Citations