Cardiac Magnetic Resonance for Evaluating Catheter Related FDG Avidity.

A 53-year-old female with a history of metastatic left arm melanoma presented for F(18) fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) which showed a moderately FDG avid focus at her port catheter tip near the cavoatrial junction. Although catheter tip related FDG avidity has previously been suggested to be bland thrombus or infection, melanoma can metastasize to unusual locations including the superior vena cava. In addition, the patient had an elevated risk of anticoagulation due to a history of hemorrhagic brain metastases. Therefore, confirmatory cardiac magnetic resonance (CMR) was obtained and findings were consistent with bland catheter-related thrombus.

Metabolic Activity by 18F-FDG-PET/CT Is Prognostic for Stage I and II Pancreatic Cancer.

PURPOSE: Metabolic activity, as defined by F-FDG uptake on PET, is a prognostic marker for multiple malignancies; however, no study has examined the prognostic value of imaging with FDG PET in stage I and II pancreatic cancer. We examined the value of PET FDG uptake in early-stage pancreatic cancer patients. METHODS: We identified patients with early-stage pancreatic cancer (I-II) who had FDG PET scan performed as part of their preoperative evaluation. The patients were divided into either high or low FDG uptake according to the median primary tumor standard uptake value (SUVmax). Our primary end points were overall survival (OS) and recurrence-free survival (RFS). Kaplan-Meier estimate was used for survival analysis. Pathologic data were compared using the Fisher exact and χ tests. RESULTS: One hundred five patients were identified: 51 patients with low FDG uptake and 54 patients with high FDG uptake. Eighty-five patients (81%) had PET avid tumors, whereas 20 (19%) patients did not. High FDG uptake correlated with pathologic stage (P = 0.012). Patients with low FDG uptake had significantly better median OS than patients with high FDG uptake (28 vs. 16 months; P = 0.036). Patients with low-FDG uptake had significantly longer median RFS than patients with high FDG uptake (14 vs. 12 months; P = 0.049). CONCLUSIONS: Low FDG uptake in PET scans in patients with stage I and II pancreatic cancer correlates with improved OS and RFS. This supports the concept that glucose metabolic pathways are important in pancreatic cancer biology and that PET scan activity can be used as a prognostic biomarker after pancreatectomy.

Variance of SUVs for FDG-PET/CT is greater in clinical practice than under ideal study settings.

PURPOSE: Measurement variance affects the clinical effectiveness of PET-based measurement as a semiquantitative imaging biomarker for cancer response in individual patients and for planning clinical trials. In this study, we measured test-retest reproducibility of SUV measurements under clinical practice conditions and recorded recognized deviations from protocol compliance. METHODS: Instrument performance calibration, display, and analyses conformed to manufacture recommendations. Baseline clinical (18)F-FDG PET/CT examinations were performed and then repeated at 1 to 7 days. Intended scan initiation uptake period was to repeat the examinations at the same time for each study after injection of 12 mCi FDG tracer. Avidity of uptake was measured in 62 tumors in 21 patients as SUV for maximum voxel (SUV(max)) and for a mean of sampled tumor voxels (SUV(mean)). RESULTS: The range of SUV(max) and SUV(mean) was 1.07 to 21.47 and 0.91 to 14.69, respectively. Intraclass correlation coefficient between log of SUV(max) and log of SUV(mean) was 0.93 (95% confidence interval [CI], 0.88-0.95) and 0.92 (95% CI, 0.87-0.95), respectively.Correlation analysis failed to show an effect on uptake period variation on SUV measurements between the 2 examinations, suggesting additional sources of noise.The threshold criteria for relative difference from baseline for the 95% CI were ± 49% or ± 44% for SUV(max) or SUV(mean), respectively. CONCLUSIONS: Variance of SUV for FDG-PET/CT in current clinical practice in a single institution was greater than expected when compared with benchmarks reported under stringent efficacy study settings. Under comparable clinical practice conditions, interpretation of changes in tumor avidity in individuals and assumptions in planning clinical trials may be affected.

Pregnancy-associated breast cancer patients can safely undergo lymphatic mapping.

As more women put off pregnancy until their 30s and beyond, the possibility of pregnancy-associated breast cancer (PABC) will rise. Treatment options for patients with PABC need to consider possible harm to the fetus. The goal of this study is to review our institution's experience with sentinel lymph node (SLN) biopsies in patients with PABC. A prospectively accrued breast Institutional Review Board (IRB) approved data base was searched under separate IRB approval for cases of SLN biopsy in patients with PABC. Ten patients were identified between 1994 and 2006 out of 5,563 patients. A chart review was performed on all 10 patients. Ten patients with PABC and an average gestation age of 15.8 weeks underwent SLN biopsy. All patients successfully mapped. Positive SLN were identified in 5/10 patients (50%) while there was no evidence of metastases in 5/10 patients (50%). 9/10 (90%) of patients went on to deliver healthy children without any reported problems. One patient (10%) decided to terminate her pregnancy in the first trimester following surgery prior to the start of chemotherapy. SLN biopsy can safely be performed in patients with PABC with minimal risk to the fetus. By performing a SLN biopsy, a large proportion of patients with PABC may be spared the risk of a complete axillary lymph node dissection.

Recent advances in breast-specific imaging.

BACKGROUND: Imaging the breast is a vital component not only for breast cancer screening, but also for diagnosis, evaluation, treatment, and follow-up of patients with breast cancer. METHODS: The author reviews recent advances and also provides her personal experience in describing the status of digital mammography, computer-aided detection, dedicated magnetic resonance imaging (MRI), and positron-emission mammography for evaluating the breast. RESULTS: Full-field digital mammography is superior to standard mammography in women under 50 years of age and in those with dense breasts. Computer-aided detection assists inexperienced mammographers and enhances detection of microcalcifications in dense breasts. Breast MRI is useful in preoperative evaluation, clarification of indeterminate mammograms, and follow-up of BRCA mutation carriers. The specificity of MRI remains problematic, however. Positron-emission mammography promises enhanced detection of ductal carcinoma in situ (DCIS), even when not associated with microcalcifications, and should aid surgical planning. CONCLUSIONS: These four significant advances in breast imaging have all improved the sensitivity of detecting breast abnormalities. Cost issues, however, may limit the widespread application of these advances.

High-performance wavelet compression for mammography: localization response operating characteristic evaluation.

PURPOSE: To evaluate the accuracy of a visually lossless, image-adaptive, wavelet-based compression method for achievement of high compression rates at mammography. MATERIALS AND METHODS: The study was approved by the institutional review board of the University of South Florida as a research study with existing medical records and was exempt from individual patient consent requirements. Patient identifiers were obliterated from all images. The study was HIPAA compliant. An algorithm based on scale-specific quantization of biorthogonal wavelet coefficients was developed for the compression of digitized mammograms with high spatial and dynamic resolution. The method was applied to 500 normal and abnormal mammograms from 278 patients who were 32-85 years old, 85 of whom had biopsy-proved cancer. Film images were digitized with a charge-coupled device-based digitizer. The original and compressed reconstructed images were evaluated in a localization response operating characteristic experiment involving three radiologists with 2-10 years of experience in reading mammograms. RESULTS: Compression rates in the range of 14:1 to 2051:1 were achieved, and the rates were dependent on the degree of parenchymal density and the type of breast structure. Ranges of the area under the receiver operating characteristic curve were 0.70-0.83 and 0.72-0.86 for original and compressed reconstructed mammograms, respectively. Ranges of the area under the localization response operating characteristic curve were 0.39-0.65 and 0.43-0.71 for original and compressed reconstructed mammograms, respectively. The localization accuracy increased an average of 6% (0.04 of 0.67) with the compressed mammograms. Localization performance differences were statistically significant with P = .05 and favored interpretation with the wavelet-compressed reconstructed images. CONCLUSION: The tested wavelet-based compression method proved to be an accurate approach for digitized mammography and yielded visually lossless high-rate compression and improved tumor localization.

Clinical evaluation of a new digitizing device for improved film mammography.

RATIONALE AND OBJECTIVES: The study was designed to evaluate a new digitizing device, the iView (Maxxvision, LLC, Gainesville, FL), which aims to replace the magnifying glass in mammography with real-time film digitization, display, and processing. MATERIALS AND METHODS: A receiver operating characteristic (ROC) experiment was performed with 5 certified mammographers and 114 mammograms that were read with and without the iView. A satisfaction survey was also conducted on the system's features and usefulness. RESULTS: Data analysis suggested that (1) Cancer sensitivity could improve with the use of the iView system. ROC area differences showed improvements from 2% to 24% although these were not always statistically significant. At a false positive rate of 0.2, the true positive rate increased up to 60% depending on the set of cases and the observer's experience. (2) Specificity could also be improved. At a true positive rate of 0.9, the false positive rate decreased by as much as 55%. (3) Most observers felt more confident in their decisions when using the iView, although the prototype's ergonomic problems did not allow full utilization of its capabilities. CONCLUSION: Our pilot clinical study showed that the iView has the potential to improve mammogram interpretation. In addition, the system could broaden the applicability of electronic information and provide wider access to digital technology through a relatively simple and cost-effective approach. Observers recommended several improvements in the ergonomics and default display of the system that are currently implemented by the company. A larger clinical study of the improved system is necessary to clearly demonstrate its clinical value for mammography.

Improved interpretation of digitized mammography with wavelet processing: a localization response operating characteristic study.

OBJECTIVE: Our objective was the implementation and evaluation of a novel enhancement technique for improved interpretation of high-resolution digitized mammograms from computer monitors. MATERIALS AND METHODS: A wavelet algorithm was designed to attenuate the image spectral characteristics responsible for the long-range image correlation that often interferes with digital display. The algorithm was evaluated with a localization response operating characteristic (LROC) experiment with 500 negative, benign, and cancer cases with masses and calcification clusters. Three observers reviewed the original and wavelet-enhanced images on a 5-Mpixel monitor using a custom-made workstation user interface. RESULTS: Performance indexes were estimated for four different case combinations, each observer, and each interpretation mode. Wavelet enhancement improved the performance of all observers in all case combinations. Detection accuracy ranged from 0.678 to 0.827 for the unprocessed original data and 0.709-0.871 for the enhanced cases. Localization accuracy ranged from 0.547 to 0.785 for the original images and 0.568-0.847 for the enhanced cases, yielding increases of 5-15%. The difference between enhanced and original performances was statistically significant at the 0.10 level and in a few combinations at the 0.05 level. CONCLUSION: Soft-copy digitized mammography could replace standard film mammography under appropriate display parameters and conditions. The optimization of the soft-copy quality is expected to require more advanced processing techniques than standard gray-scale adjustments. Wavelet-based algorithms, such as the one proposed here, offer better soft-copy quality than the originals and a better starting point for additional manual gray-scale adjustments or automated postprocessing.