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.

Combination of external beam radiotherapy (EBRT) with intratumoral injection of dendritic cells as neo-adjuvant treatment of high-risk soft tissue sarcoma patients.

PURPOSE: The goal of this study was to determine the effect of combination of intratumoral administration of dendritic cells (DC) and fractionated external beam radiation (EBRT) on tumor-specific immune responses in patients with soft-tissue sarcoma (STS). METHODS AND MATERIAL: Seventeen patients with large (>5 cm) high-grade STS were enrolled in the study. They were treated in the neoadjuvant setting with 5,040 cGy of EBRT, split into 28 fractions and delivered 5 days per week, combined with intratumoral injection of 10(7) DCs followed by complete resection. DCs were injected on the second, third, and fourth Friday of the treatment cycle. Clinical evaluation and immunological assessments were performed. RESULTS: The treatment was well tolerated. No patient had tumor-specific immune responses before combined EBRT/DC therapy; 9 patients (52.9%) developed tumor-specific immune responses, which lasted from 11 to 42 weeks. Twelve of 17 patients (70.6%) were progression free after 1 year. Treatment caused a dramatic accumulation of T cells in the tumor. The presence of CD4(+) T cells in the tumor positively correlated with tumor-specific immune responses that developed following combined therapy. Accumulation of myeloid-derived suppressor cells but not regulatory T cells negatively correlated with the development of tumor-specific immune responses. Experiments with (111)In labeled DCs demonstrated that these antigen presenting cells need at least 48 h to start migrating from tumor site. CONCLUSIONS: Combination of intratumoral DC administration with EBRT was safe and resulted in induction of antitumor immune responses. This suggests that this therapy is promising and needs further testing in clinical trials design to assess clinical efficacy.

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.

Computerized analysis of tissue density effect on missed cancer detection in digital mammography.

This paper presents a study of the analysis of breast density in missed cancer cases and the effect of tissue density on cancer detection. A total of 100 missed cancer cases were collected. The breast density tissue was segmented with a statistical-based method. A set of tests was then applied to examine: (1) the differences in density between the mammograms at the detected stage and that at missed stage; (2) the density difference between the cancerous mammograms and their contra-lateral normal mammograms in the missed cancer cases; (3) the effect of breast density on CAD cancer detection. The results demonstrate that breast density is an important factor affecting not only radiologist's reading but also CAD performance. In order to improve early detection of breast cancer, a special effort should be directed to the high dense breast cases in CAD system design.

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.

Breast Tissue Density and CAD Cancer Detection in Digital Mammography.

This study is part of the research of improving early detection of breast cancer in screening mammograms by focusing on computerized analysis and detection of cancers missed by radiologists. It is directed to the analysis of breast density in missed cancer cases and the effect of tissue density on cancer detection. A total of 100 missed cancer cases were collected which were used to generate three different datasets including mammograms with missed cancer, mammograms with screening-detected cancer and normal mammograms. A statistical-based method was applied to segment the breast density tissue. The percentage of the segmented density tissue area out of the whole breast area is calculated as the index of breast density. A set of tests was applied to examine (1) the differences in density between the mammograms at the detected stage and that at missed stage, (2) the density difference between the normal mammograms and the cancerous mammograms; (3) the effect of breast density on CAD cancer detection. The results demonstrate that (1) no significant difference in breast density between the detected and missed stages; (2) the density of cancerous mammograms is significantly higher than normal mammograms; (3) similar to mammogram screening by radiologists, the lesions occurred in dense breasts are more likely to be missed in CAD detection especially at their early stage.

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.

Radioactive seed localization breast biopsy and lumpectomy: can specimen radiographs be eliminated?

BACKGROUND: Wire localization (WL) is the current standard for surgical diagnosis of nonpalpable breast lesions. Many disadvantages inherent to WL are solved with radioactive seed localization (RSL). This trial investigated the ability of RSL to reduce the need for specimen radiographs and operating room delays associated with WL. METHODS: A total of 134 women were entered onto an institutional review board-approved study. RSL was performed by placing a titanium seed containing.29 to 20 mCi of iodine-125 to within 1 cm of the suggestive breast lesion. The surgeon used a handheld gamma detector to locate and excise the iodine-125 seed and the lesion. RESULTS: Specimen radiographs were eliminated in 98 (79%) of 124 patients. Surgical seed retrieval was 100% in 124 patients. No seed migration occurred after correct radiographical placement. A total of 26 (21%) of 124 patients required a specimen radiograph; 22 (85%) of these 26 were performed for microcalcifications. CONCLUSIONS: After surgical removal, RSL can eliminate specimen radiographs when the radiologist accurately places the seed and the pathologist grossly identifies the lesion. If small microcalcifications are noted before surgery, then specimen radiographs may be necessary. RSL reduced requirements for specimen radiographs, decreased OR time, improved incision placement, and improved resections to clear margins.

Lymphatic Mapping and Sentinel Lymph Node Biopsy.

The status of the regional nodal basin remains the most important prognostic indicator of survival. The current standard of care for the management of invasive breast cancer is the complete removal of the tumor, with documentation of negative margins by either mastectomy or lumpectomy, followed by complete axillary lymph node dissection. Data suggest that complete lymph node dissection (CLND) provides better local control of the disease and may actually offer a survival advantage. Lymphatic mapping and sentinel lymph node (SLN) biopsy are clearly changing this long-held paradigm and have the potential to change the standard of surgical care of the breast cancer patient. The purpose of this report is to describe the lymphatic mapping experience at the H. Lee Moffitt Cancer Center and Research Institute. From April 1994 to January 1999, 1,147 consecutive breast cancer patients were enrolled in an institutional review board-approved lymphatic mapping protocol. Lymphatic mapping was performed using Tc99m-labeled sulfur colloid and isosulfan blue dye. An SLN was defined as any blue node and/or any hot node with ex vivo radioactivity counts >/=10 times an excised non-SLN or in situ radioactivity counts >/=3 times the background counts. Lymphatic mapping was successful in identifying the SLN in 1,098 of 1,147 (95.7%) cases. In the first 186 patients, all of whom underwent CLND following SLN biopsy, one false-negative biopsy was encountered for a false-negative rate of 0.83%. The method of diagnosis (excisional versus minimally invasive) does not appear to impact on lymphatic mapping. Tumor size, however, is directly related to the probability of axillary lymph node involvement. Advances in technology and the development of minimally invasive surgical techniques have heralded a new era in surgery. Lymphatic mapping and SLN biopsy may actually prove to be a more accurate method of identifying metastases to the axilla by allowing a more focused pathologic examination of the axillary node(s) at highest risk for metastasis. With adequate training, this technique can be readily implemented as a valuable tool in the surgical treatment of breast cancer.