Magnetic resonance imaging of the breast.

BACKGROUND: Magnetic resonance imaging (MRI) has the potential to become a useful adjunct in breast imaging. Contrast-enhanced breast MRI has demonstrated a high sensitivity in the detection of invasive breast cancer. In clinical studies, breast MRI has often altered the course of patient care. Although promising results have been generated, MRI of the breast is currently in a development stage. METHODS: The authors reviewed the literature on the potential indications, sensitivity, specificity, and limitations of MRI of the breast. RESULTS: Reported advantages of MRI of the breast over conventional imaging techniques include improved staging and treatment planning, enhanced evaluation of the augmented breast, better detection of recurrence, and improved screening of high-risk women. Contrast-enhanced breast MRI is a sensitive modality for detecting breast cancer, but its variable specificity is a major limitation. CONCLUSIONS: MRI of the breast is emerging as a valuable adjunct to mammography and sonography for specific clinical indications. Additional clinical studies that define indications, interpretation criteria, imaging parameters, and cost effectiveness are needed. A multi-institutional study designed to address these issues is in progress.

Cost consequences of sentinel lymph node biopsy in the treatment of breast cancer. A preliminary analysis.

OBJECTIVES: To assess whether sentinel lymph node biopsy (SLNB), an alternative to axillary lymph node dissection in treating female breast cancer, affords any cost savings. METHODS: We profile cumulative treatment costs of 811 breast cancer patients, 555 of whom received SLNB. Univariate and multivariate statistical tests are used to appraise whether these cost profiles differ between SLNB and other patients. RESULTS: The statistical results are mixed. However, none supports the conjecture that SLNB necessarily lowers the cost of treating the average breast patient. CONCLUSIONS: SLNB may be cost-effective, but longer term costs and outcomes must be estimated before firm conclusions can be reached.

Positron emission tomography in initial staging and diagnosis of persistent or recurrent disease.

Positron emission tomography (PET) constitutes a major advance in the diagnosis, staging, prognostic assessment, and follow-up of lung cancer. However, it is not a magic bullet that can solve all of the uncertainties that beguile the imaging of this disease. Small lesions, particularly those in the brain, may often be missed with PET, and three-dimensional localization of suspected sites may also be unreliable. We are still learning how best to apply this new technology in an environment that demands the efficient use of medical resources. PET will probably be used most enthusiastically in the prethoracotomy staging of patients who are considered operable or probably operable on the basis of computed tomography and in the assessment of treatment response and disease recurrence when clinical management will be determined by prompt recognition of these events.

Melanoma lymphoscintigraphy and lymphatic mapping.

Lymphoscintigraphy in melanoma has proven to be a reliable method to identify regional lymph nodes at risk for metastases. The first lymph node to drain a cutaneous lesion, the sentinel lymph node (SLN), is predictive of the metastatic status of the regional lymph node group. Lymphatic mapping allows for the identification of the SLN and for selective lymph node sampling. Selective lymph node sampling is less invasive and because only a small quantity of high-risk tissue is submitted for pathological examination, it allows for a more complete and comprehensive pathological examination, which identifies melanoma with up to 100 times the sensitivity of conventional examinations.

Radiation safety and nuclear medicine policies and procedures.

There is a growing concern over possible adverse effects from medical applications of ionizing radiation. Hospital personnel must be educated in procedures to minimize exposure to themselves and their patients. Basic radiation safety procedures to protect personnel and patients are discussed. Examples of the nuclear medicine policies and procedures used for lymphatic mapping are provided.

Lymphoscintigraphy in malignant melanoma and breast cancer.

Lymphoscintigraphy is the injection of radioactive particles that are then imaged as they pass through lymphatic vessels to their respective lymph nodal drainage basins. Lymphoscintigraphy is receiving increasing interest as a means to stage regional lymph nodes in early stage malignancy. Injection and imaging techniques for performing breast and melanoma lymphoscintigraphy are discussed in this article.

Cost analysis of sentinel lymph node biopsy as an alternative to elective lymph node dissection in patients with malignant melanoma.

In the current era of managed care and cost containment, physicians and administrators are placed in the predicament of increasing quality of care while decreasing costs. The purpose of this article is to offer a cost analysis, while also demonstrating what patients, providers, payers, employers, and industry may stand to gain from establishing sentinel lymph node biopsy as a standard care in certain groups of patients.

The progression of melanoma nodal metastasis is dependent on tumor thickness of the primary lesion.

BACKGROUND: Recent results of several clinical trials using the technique of intraoperative lymphatic mapping and sentinel lymph node (SLN) biopsy confirm the validity of the concept of there being an order to the progression of melanoma nodal metastases. This report reviews the H. Lee Moffitt Cancer Center experience with this procedure, one of the largest series described to date. These data demonstrate that the involvement of the SLNs, as well as higher-echelon nodes, is directly proportional to the melanoma tumor thickness, as measured by the method of Breslow. METHODS: The investigators at the H. Lee Moffitt Cancer Center retrospectively reviewed their experience using lymphatic mapping and SLN biopsies in the treatment of malignant melanoma. All eligible patients with primary malignant melanomas underwent preoperative and intraoperative mapping of the lymphatic drainage of their primary sites, along with SLN biopsies. All patients with positive SLNs underwent complete regional basin nodal dissection. For 20 consecutive patients with one positive SLN, all of the nodes from the complete lymphadenectomy were serially sectioned and examined by S-100 immunohistochemical analysis, to detect additional metastatic disease. RESULTS: Six hundred ninety-three patients consented to undergo lymphatic mapping and SLN biopsy. The SLNs were successfully identified and collected for 688 patients, yielding a 99% success rate. One hundred patients (14.52%) showed evidence of nodal metastasis. The rates of SLN involvement for primary tumors with thicknesses of <0.76 mm, 0.76-1.0 mm, 1.0-1.5 mm, 1.5-4.0 mm, and >4.0 mm were 0%, 5.3%, 8%, 19%, and 29%, respectively. Eighty-one patients underwent complete lymph node dissection after observation of a positive SLN, and only six patients with positive SLNs demonstrated metastatic disease beyond the SLN (7.4%). The tumor thicknesses for these six patients ranged from 2.8 to 6.0 mm. No patient with a tumor thickness of <2.8 mm was found to have evidence of metastatic disease beyond the SLN in complete lymph node dissection. All 20 patients with a positive SLN for whom all of the regional nodes were serially sectioned and examined by S-100 immunohistochemical analysis failed to show additional positive nodes. CONCLUSIONS: These results suggest that regional lymph node involvement may be dependent on the thickness of the primary tumor. As the primary tumor thickness increases, so does the likelihood of involvement of SLNs and higher regional nodes in the basin beyond the positive SLNs.

Simulation model of mammographic calcifications based on the American College of Radiology Breast Imaging Reporting and Data System, or BIRADS.

RATIONALE AND OBJECTIVES: The authors developed and evaluated a method for the simulation of calcification clusters based on the guidelines of the Breast Imaging Reporting and Data System of the American College of Radiology. They aimed to reproduce accurately the relative and absolute size, shape, location, number, and intensity of real calcifications associated with both benign and malignant disease. MATERIALS AND METHODS: Thirty calcification clusters were simulated by using the proposed model and were superimposed on real, negative mammograms digitized at 30 microns and 16 bits per pixel. The accuracy of the simulation was evaluated by three radiologists in a blinded study. RESULTS: No statistically significant difference was observed in the observers' evaluation of the simulated clusters and the real clusters. The observers' classification of the cluster types seemed to be a good approximation of the intended types from the simulation design. CONCLUSION: This model can provide simulated calcification clusters with well-defined morphologic, distributional, and contrast characteristics for a variety of applications in digital mammography.

The clinical relevance of sentinel lymph nodes identified with radiolymphoscintigraphy.

BACKGROUND: The purpose of this case report is to illustrate the utility of radio-guided mapping of sentinel lymph nodes (SLN's) as demonstrated by the technique's successful identification of nodes containing metastatic disease that would have been left behind if only the visual-oriented vital blue dye mapping technique had been used. METHOD: The patient underwent preoperative lymphoscintigraphy and intra-operative lymphatic mapping using vital blue dye and radiolymphoscintigraphy using the Neoprobe (handheld gamma probe). Nodes which were blue and/or "hot" (i.e., radioactive counts were three times the background count) were considered SLN's. RESULTS: Four SLN's were harvested, all of which were "hot" but only one of which was both "hot" and blue. Pathology revealed that the two SLN's positive for metastatic disease were not blue. CONCLUSION: While the blue dye lymphatic mapping technique provides the surgeon with a visual road map in the identification of SLN's, the Neoprobe increases the success rate of localization when compared to vital blue dye mapping due to the reliable migration of radiocolloid to the SLN's in the regional basin. Radiolymphoscintigraphy also increases the accuracy and efficiency of the SLN harvest by providing a directed dissection to the level of the nodes in the basin. The Neoprobe increases the yield of SLN's, some of which are clinically relevant since they contain metastatic disease.

Interpretation of calcifications in screen/film, digitized, and wavelet-enhanced monitor-displayed mammograms: a receiver operating characteristic study.

RATIONALE AND OBJECTIVES: The acceptance of filmless digital mammography is currently limited by digitization and display drawbacks, as well as bias toward hard-copy interpretation. In the current study, we evaluated a wavelet-based image enhancement method for the filmless interpretation of breast calcifications. METHODS: A set of 100 mammograms (58 with calcification clusters) was digitized at 105 microns and 4,096 gray levels per pixel and was processed with nonlinear filters and wavelets. Standard receiver operating characteristic analysis was performed by four radiologists, who independently read the films, the unprocessed digital images, and unprocessed and wavelet-enhanced digital images presented simultaneously. RESULTS: Statistical differences were observed between screen/film and unprocessed digitized mammography displayed on monitors. Differences were not significant when wavelet enhancement was included in the monitor display. Interobserver variation in the digitized reading was greater than in film reading, but the wavelet enhancement reduced the difference. CONCLUSION: Wavelet-enhanced digital mammograms may assist radiologists in diagnosing calcifications directly from computer monitors and may compensate for current technologic limitations. A study with a larger data-base is needed before this method is accepted for clinical use.

Intraoperative radio-lympho-scintigraphy improves sentinel lymph node identification for patients with melanoma.

BACKGROUND: The sentinel lymph node (SLN), the first node draining the primary tumor site, has been shown to reflect the histologic features of the remainder of the lymphatic basin in patients with melanoma. Intraoperative localization of the SLN, first proposed by Morton and colleagues, has been accomplished with the use of a vital blue dye mapping technique. Technical difficulties resulting in unsuccessful explorations have occurred in up to 20% of the dissections. OBJECTIVES: The authors aimed to define the SLN using gamma detection probe mapping and to determine whether intraoperative radiolymphoscintigraphy using technetium sulfur colloid and a hand-held gamma-detecting probe could be used to improve detection of all SLNs for patients with melanoma. METHODS: To ensure that all initial nodes draining the primary site were removed at the time of selective lymphadenectomy, the authors used intraoperative radiolymphoscintigraphy to confirm the location of the SLN, which was determined initially with the preoperative lymphoscintigram and the intraoperative vital blue dye injection. PATIENT POPULATION: The patient population consisted of 106 consecutive patients who presented with cutaneous melanomas larger than 0.75 mm in all primary site locations. RESULTS: The preoperative lymphoscintigram revealed that 22 patients had more than one lymphatic basin sampled. Two hundred SLNs and 142 neighboring non-SLNs were harvested from 129 basins in 106 patients. After the skin incision was made, the mean ratio of hot spot to background activity was 8.5:1. The mean ratio of ex vivo SLN-to-non-SLN activity for 72 patients who had SLNs harvested was 135.6:1. When correlated with the vital blue dye mapping, 139 of 200 (69.5%) SLNs demonstrated blue dye staining, whereas 167 of 200 (83.5%) SLNs were hot according to radioisotope localization. With the use of both intraoperative mapping techniques, identification of the SLN was possible for 124 of the 129 (96%) basins sampled. Micrometastases were identified in SLNs of 16 of the 106 (15%) patients by routine histologic analysis. CONCLUSION: The use of intraoperative radiolymphoscintigraphy can improve the identification of all SLNs during selective lymphadenectomy.

The identification and mapping of melanoma regional nodal metastases: minimally invasive surgery for the diagnosis of nodal metastases.

The most controversial part of melanoma surgical care involves the role of elective lymph node dissection (ELND). Whereas proponents cite retrospective studies demonstrating the ability to control regional metastases and more accurate staging, opponents cite the unnecessary morbidity of a complete node dissection for the majority of patients. The technology of sentinel node mapping and selective lymphadenectomy, defined as the identification and removal of the first node into which the primary melanoma drains, may revolutionize melanoma care. If the sentinel node is negative, then theoretically the remainder of the nodes should also be negative (no "skip" metastases), and a complete lymphadenectomy would not be required to control occult nodal disease. The location of the sentinel node may be variable in the lymphatic basin. Ideally, the surgeon needs a map of the position of the sentinel node in reference to the other nodes in the basin in order to do the procedure under local anesthesia with small incisions. In this way, patients are subjected to minimal morbidity and the procedure can be performed as an out-patient. Twenty-nine patients with clinically negative nodes and melanomas greater than 0.76 mm in thickness were judged to be candidates for ELND. Preoperative lymphoscintigraphy in two planes was used to mark the sentinel node, and the patients were taken to the operating room for intraoperative lymphatic mapping and sentinel node biopsy followed by complete dissection.(ABSTRACT TRUNCATED AT 250 WORDS)

PC-based multiparameter full-color display for tissue segmentation in MRI of adnexal masses.

OBJECTIVE: Our purpose was to apply full-color composite generation methods to multiparameter MRI to assess the ability of the technique to quantitatively segment clinically important anatomic and pathologic tissues. MATERIALS AND METHODS: With use of a personal computer with a 386 microprocessor and full-color (24 bit) graphics display capabilities, custom and commercially available image-processing softwares were applied to spatially aligned multiparameter SE MR image sets obtained from six patients undergoing diagnostic work-up for suspected adnexal or pelvic masses to generate intensity-based color composites. To quantitatively assess the ability of this technique to differentially segment anatomically and pathologically confirmed tissue types into unique color regions within the full-color spectrum, color image analysis was performed on the multiparameter color composites within each patient case, and the results were compared using 95% confidence intervals. RESULTS: Based on the results of pathologic correlation and color image analysis, the generation of full-color composites represents a feasible technique for compressing the diverse tissue contrast data present in multiparameter MR images of adnexal masses. CONCLUSION: With this technique, it is possible to generate composites that simultaneously display uniquely color-coded anatomic and pathologic tissue information within the context of partially natural-appearing images.

Diagnostic imaging in cancer.

Screening chest radiographs do not reduce mortality from lung cancer. Should an incidental noncalcified pulmonary parenchymal nodule be discovered, chest CT will demonstrate one third of such patients to, in fact, have the multiple nodules of metastatic disease. CT is very helpful to guide fine needle aspiration biopsy of lung lesions and to assist in evaluation for resectability. MR can be helpful in special circumstances, including the definition of the extent of paravertebral, superior sulcus, and diaphragmatic lesions. Endorectal ultrasound is not sensitive enough to function as a screening tool for prostate cancer but is used routinely to guide biopsies. CT and MR are rarely helpful in staging this disease. Given the highly characteristic trait of bone metastasis in prostate cancer, a bone scan is mandatory in all patients. Double contrast barium enema can be used as an adjunct or alternative to sigmoidoscopy for colorectal cancer screening, in the preoperative evaluation of patients, and in postoperative surveillance. CT and MR can detect macroscopic adenopathy and liver metastases; CT is generally the preferred study. Screening mammography can have a major impact in reducing breast cancer mortality. It is recommended that a baseline study be obtained at age 35. Annual or biannual examinations should commence at age 40. Any palpable lesion, whether or not it is demonstrated mammographically, must be subjected to biopsy. Ultrasound is the most useful initial imaging study for evaluating pelvic masses. MR will, on occasion, identify the origin of a mass not determinable from ultrasound scan. MR is particularly valuable to identify parametrial spread (inoperability) of cervical cancer, and has been underused for this purpose. Surgery remains the mainstay for the staging of ovarian and endometrial cancer, although CT can be helpful to identify macroscopic relapse, ascites, or liver metastases. Bone scan and liver CT remain the standard procedures for detecting metastases in these respective organ systems. MR can be invaluable in the imaging of epidural metastasis and spinal cord compression in patients with vertebral metastatic disease. Contrast-enhanced MR is more sensitive than contrast-enhanced CT for detecting brain metastases, but the latter remains a useful tool. Chest CT can improve the detection of pulmonary metastases when this is of crucial importance.

Lymphoscintigraphy in malignant melanoma.

The development and rationale for the use of lymphoscintigraphy in the preoperative evaluation of patients with malignant melanoma being considered for elective lymph node dissection is reviewed. This overview is updated by an analysis of 135 patients with early stage malignant melanoma involving the head, neck, shoulders, and trunk at Moffitt Cancer Center and Research Institute at the University of South Florida (Tampa, FL). High discordancy rates (overall, 41%) were seen between drainage patterns predicted from historical anatomical guidelines and those revealed by the lymphoscintigraphic examination. The high discordancy rate was most pronounced in the head (64%) and the neck (73%). Surgical management was changed in 33% of the patients, overall. A preoperative lymphoscintigram is recommended for all patients with melanoma with head, neck, and truncal lesions evaluated for elective lymph node dissection as the lymphatic drainage patterns are often unpredictable and variable.

Magnetic resonance imaging evaluation of congenital dislocation of the hips.

Magnetic resonance (MR) images were obtained preoperatively and postoperatively for 12 pediatric patients with congenital dislocation of the hip (CDH). The images were compared with arthrograms and computed tomography scans. The MR images were more accurate in defining soft-tissue anatomy, hip position, and obstructive factors to relocation. MR imaging is an efficient diagnostic tool in CDH.