Detailed DescriptionCollection Statistics | |
---|
Modalities | MR | Number of Patients | 222 | Number of Studies | 847 | Number of Series | 7880 | Number of Images | 386,528 | Images Size (GB) | 76.2 GigaBytes |
Imaging time points: MRI exams were performed within four weeks prior to starting anthracycline-cyclophosphamide chemotherapy (T1, MRI1), at least 2 weeks after the first cycle of AC and prior to the second cycle of AC (T2, MRI2), between anthracycline-cyclophosphamide treatment and taxane therapy if taxane was administered (T3, MRI3), and after the final chemotherapy treatment and prior to surgery (T4, MRI4). The study schema is shown in Figure 1
Figure 1. CALGB 150007 and ACRIN 6657 study schema. Imaging protocol: MR imaging was performed on a 1.5 Tesla field strength scanner using a dedicated breast radiofrequency coil. The image acquisition protocol included a localization scan and T2-weighted sequence followed by a contrast-enhanced T1-weighted series. All imaging was performed unilaterally over the symptomatic breast and in the sagittal orientation. The contrast-enhanced series consisted of a high resolution (≤1mm in-plane spatial resolution) three-dimensional, fat-suppressed, T1-weighted gradient echo sequence with TR≤20 ms, TE = 4.5 ms, flip angle ≤ 45º, 16-18 cm field-of-view, minimum matrix 256x192, 64 slices, slice thickness ≤ 2.5 mm. Scan time length for the T1-weighted sequence was required to be between 4.5 and 5 minutes. The sequence was acquired once before contrast injection and repeated at least twice following injection. Tumor diameter measurement and volumetric analysis: Tumor longest diameter (LD) was measured by the site radiologist as the greatest extent of disease on baseline MR images, including intervening areas of non-enhancing tissue. The same measurement direction was used on all subsequent MRI exams. The primary predictor variable, functional tumor volume (FTV) was measured from contrast-enhanced images using the signal enhancement ratio (SER) method. Volumetric analysis, including Quality Control assessment, was performed centrally at the Breast Imaging Research Program (BIRP) laboratory at University of California at San Francisco (UCSF). |