Scintimammography in patients with minimal mammographic or clinical findings

Recent Advances in Spontaneous Raman Spectroscopic Imaging: Instrumentation and Applications

BACKGROUND

Spectroscopic imaging based on the spontaneous Raman scattering effects can provide unique fingerprint information in relation to the vibration bands of molecules. Due to its advantages of high chemical specificity, non-invasive detection capability, low sensitivity to water, and no special sample pretreatment, Raman Spectroscopic Imaging (RSI) has become an invaluable tool in the field of biomedicine and medicinal chemistry.

METHODS

There are three methods to implement RSI, including point scanning, line scanning and wide-field RSI. Point-scanning can achieve two-and three-dimensional imaging of target samples. High spectral resolution, full spectral range and confocal features render this technique highly attractive. However, point scanning based RSI is a time-consuming process that can take several hours to map a small area. Line scanning RSI is an extension of point scanning method, with an imaging speed being 300-600 times faster. In the wide-field RSI, the laser illuminates the entire region of interest directly and all the images then collected for analysis. In general, it enables more accurate chemical imaging at faster speeds.

RESULTS

This review focuses on the recent advances in RSI, with particular emphasis on the latest developments on instrumentation and the related applications in biomedicine and medicinal chemistry. Finally, we prospect the development trend of RSI as well as its potential to translation from bench to bedside.

CONCLUSION

RSI is a powerful technique that provides unique chemical information, with a great potential in the fields of biomedicine and medicinal chemistry.

Breast-specific gamma imaging with 99mTc-Sestamibi and magnetic resonance imaging in the diagnosis of breast cancer--a comparative study

The purpose of this study was to compare the sensitivity and specificity of breast-specific gamma imaging (BSGI) using a high-resolution breast-specific gamma camera and magnetic resonance imaging (MRI) in patients with indeterminate breast findings. Twenty-three women with an indeterminate breast finding that required BSGI and MRI as deemed necessary by the interpreting radiologist or referring physician were included. MRI was performed on a GE 1.5T scanner and BSGI was performed on a Dilon high-resolution breast-specific gamma camera. All imaging findings were correlated with pathologic diagnosis. Thirty-three indeterminate lesions were evaluated in the study. There were a total of nine pathologically confirmed cancers. There was no statistically significant difference in sensitivity of cancer detection between BSGI and MRI. BSGI demonstrated a greater specificity than MRI, 71% and 25%, respectively. BSGI has equal sensitivity and greater specificity than MRI for the detection of breast cancer.

Alternative Breast-Imaging Approaches

Although conventional breast-imaging techniques routinely include mammography and ultrasound, growing interest in other approaches, perhaps most notably MR imaging, has drawn increasing attention to exploiting the anatomic and physiologic basis for understanding breast cancer. Nuclear medicine techniques have been applied in several circumstances with the intent of approaching or defining a role for molecular imaging, exemplified by the use of F-18 fluorodeoxyglucose and positron emission tomography. Other techniques, including exploitation of additional components of the electromagnetic spectrum, have provided novel concepts that may ripen into clinical use.

Clinical decision modeling system

Background

Decision analysis techniques can be applied in complex situations involving uncertainty and the consideration of multiple objectives. Classical decision modeling techniques require elicitation of too many parameter estimates and their conditional (joint) probabilities, and have not therefore been applied to the problem of identifying high-performance, cost-effective combinations of clinical options for diagnosis or treatments where many of the objectives are unknown or even unspecified.

Methods

We designed a Java-based software resource, the Clinical Decision Modeling System (CDMS), to implement Naïve Decision Modeling, and provide a use case based on published performance evaluation measures of various strategies for breast and lung cancer detection. Because cost estimates for many of the newer methods are not yet available, we assume equal cost. Our use case reveals numerous potentially high-performance combinations of clinical options for the detection of breast and lung cancer.

Results

Naïve Decision Modeling is a highly practical applied strategy which guides investigators through the process of establishing evidence-based integrative translational clinical research priorities. CDMS is not designed for clinical decision support. Inputs include performance evaluation measures and costs of various clinical options. The software finds trees with expected emergent performance characteristics and average cost per patient that meet stated filtering criteria. Key to the utility of the software is sophisticated graphical elements, including a tree browser, a receiver-operator characteristic surface plot, and a histogram of expected average cost per patient. The analysis pinpoints the potentially most relevant pairs of clinical options ('critical pairs') for which empirical estimates of conditional dependence may be critical. The assumption of independence can be tested with retrospective studies prior to the initiation of clinical trials designed to estimate clinical impact. High-performance combinations of clinical options may exist for breast and lung cancer detection.

Conclusion

The software could be found useful in simplifying the objective-driven planning of complex integrative clinical studies without requiring a multi-attribute utility function, and it could lead to efficient integrative translational clinical study designs that move beyond simple pair wise competitive studies. Collaborators, who traditionally might compete to prioritize their own individual clinical options, can use the software as a common framework and guide to work together to produce increased understanding on the benefits of using alternative clinical combinations to affect strategic and cost-effective clinical workflows.

Single-photon agents for tumor imaging:201TI,99mTc-MIBI, and99mTc-tetrofosmin

This review aims at fostering comprehension and knowledge not only for expert physicians who can skillfully handle various techniques for tumor imaging but also for young practitioners in the field of nuclear medicine. As image processing software and hardware become smaller, faster and better, SPECT will adapt and incorporate these advances. A principal advantage of SPECT over PET is the more widespread availability of the equipment and lower cost for the introduction of the system in community-based facilities. Moreover, SPECT has become less dependent on a limited number of acknowledged experts for its interpretation owing to a variety of handy computer tools for imaging analyses. The increasing use of PET in tumor imaging is not necessarily proportional to the decline of SPECT. General physicians' attention to SPECT technology would also increase more by evoking their interest in "tracer imaging."

Breast tumor localization using sestamibi

PURPOSE

The sensitivity of sestamibi scanning is 85% for breast lesions that measure >or=1 cm in diameter. This detection technique complements mammography and clinical examination and can benefit patients with very dense breast tissue. An innovation in nuclear imaging uses a lead marker for localization.

MATERIALS AND METHODS

A 53-year-old woman underwent scintigraphy to clarify the indeterminate findings of a mammogram. Left breast biopsies 7 and 8 years earlier had yielded benign results. Mammography revealed a somewhat asymmetric stromal pattern, but the tissue appeared stable compared with results of previous studies. No focal abnormalities were identified. The original sestamibi breast scan revealed focally increased sestamibi uptake in the left breast. She was referred for another sestamibi scan because no radiographic or palpable abnormality correlated with the scintigraphic findings, and the lesion was believed to be nonlocalizable. Histologic examination revealed high-grade, poorly differentiated infiltrating ductal adenocarcinoma.

RESULTS

After intravenous administration of Tc-99m sestamibi, the site of the lesion was identified using a lead marker, the persistence scope, and localization needles. This facilitated surgical removal.

CONCLUSION

Using a lead marker allows placement of localization wires to guide surgical breast biopsy in patients whose lesions are visible by scintigraphy but not via mammography or palpation.