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N P Alazraki

Publications and source records attributed to N P Alazraki.

At least 19 recordsLinked to original sources
PubMed2001

Sentinel node staging of early breast cancer using lymphoscintigraphy and the intraoperative gamma detecting probe.

Lymphoscintigraphy combined with intraoperative gamma-probe detection of sentinel lymph nodes in patients with inoperable early primary breast cancers is effective for staging the disease. The clinical alternative is axillary lymph node dissection, which is a far more invasive procedure and is accompanied by significant morbidity. Accuracy of staging is enhanced by immunohistochemical staining of micrometastases, which pathologists can easily perform for one to three sentinel lymph nodes, but not for 20 to 30 nodes, using axillary dissection procedure. Optimum methodology is presented for performing sentinel lymph node imaging and is important for accurate identification of sentinel node(s).

Breast Neoplasms↗
PubMed2000

Sentinel node staging of early breast cancer using lymphoscintigraphy and the intraoperative gamma-detecting probe.

Sentinel node staging for breast cancer is increasingly used in place of axillary lymph node dissection but is not yet universally accepted. The problems of non-standardized methodologies and lack of consensus on the optimum techniques to identify sentinel nodes are being addressed. Complementary use of radionuclide imaging before surgery, intraoperative probe detection, and blue dye have yielded the best reported sensitivities for finding a sentinel node (94%). The importance of imaging is summarized as identifying sentinel node(s), distinguishing sentinel from secondary nodes, guiding surgical incision planning, and facilitating lower doses. The learning curve phenomenon, which applies to the surgeon and the nuclear medicine physician, has been recognized; measures to minimize it are being implemented. Radiation exposure to operating room and pathology personnel is very low; estimates of exposure to the surgeon's hands are 0.2% of the annual whole body dose received by every human being from natural background and cosmic sources.

Breast Neoplasms↗
PubMed1999

Prognostic value of thallium-201 single-photon emission computed tomography for patients with multivessel coronary artery disease after revascularization (the Emory Angioplasty versus Surgery Trial [EAST]).

The aim of this study was to investigate the relation between reversible thallium single-photon emission computed tomography (SPECT) myocardial perfusion defects at 1-year after revascularization and quantitative indexes in Emory Angioplasty versus Surgery Trial (EAST) and outcomes 3 years after revascularization in 336 patients. EAST was a randomized controlled trial assessing cardiac outcomes for angioplasty versus bypass surgery for patients with multivessel coronary artery disease. During this prospective trial, a substudy included the evaluation of the prognostic value of reversible defects on quantitative thallium SPECT. At 1-year after revascularization, 336 patients underwent SPECT thallium-201 stress myocardial perfusion and 3-hour delayed imaging. Subsequent events, percutaneous transluminal coronary angioplasty, coronary artery bypass graft surgery, myocardial infarction, and death, were recorded at 3 years. A stress-induced reversible thallium-201 defect was defined using a quantitative index of a reversibility score >30% and severity score >500. Reversible defects were observed more frequently in the percutaneous transluminal coronary angioplasty than in the coronary artery bypass graft surgery treatment groups (46% vs 27%, p <0.001). A total of 123 patients had stress-induced, reversible thallium defects and more events than patients with other perfusion results (freedom from all events was 81.3% vs 94% [p <0.001], and freedom from myocardial infarction and death 88.3% vs 95.5% [p = 0.031]). Quantitative thallium SPECT at 1 year after revascularization risk stratifies patients as to their likelihood of major cardiac outcomes.

Aged↗
PubMed1998

Lymphoscintigraphic identification of sentinel lymph nodes: clinical evaluation of 0.22-micron filtration of Tc-99m sulfur colloid.

PURPOSE: To evaluate the use of 0.22-micron filtration of technetium-99m sulfur colloid particles in the optimization of lymphoscintigraphy. MATERIALS AND METHODS: Forty-one consecutive lymphoscintigraphic studies obtained with 0.22-micron filtration of Tc-99m sulfur colloid in 41 patients (26 men, 15 women; average age, 55.4 years) and 41 consecutive studies obtained with 5.0-micron filtration in 41 patients (20 men, 21 women; average age, 54.5 years) were retrospectively, randomly reviewed. Studies were evaluated for lymphatic channel depiction and sentinel lymph node depiction. Studies included immediate flow images (obtained at 10 seconds per frame) and multiview static images obtained up to 2 hours after intradermal Tc-99m sulfur colloid injection. RESULTS: The number of drainage beds visualized was 52 with 5.0-micron filtration and 51 with 0.22-micron filtration (P = .570). The number of lymphatic channels visualized was 45 with 5.0-micron filtration and 75 with 0.22-micron filtration (P = .006). The number of lymph nodes visualized was 102 with 5.0-micron filtration and 123 with 0.22-micron filtration (P = .123). The number of studies judged as optimal (i.e., depicted lymphatic channels leading to sentinel nodes) was 10 with 5.0-micron filtration and 19 with 0.22-micron filtration (P = .038). The number of studies with depicted lymph nodes but no depicted lymphatic channel was 15 with 5.0-micron filtration and six with 0.22-micron filtration (P = .023). CONCLUSION: The use of 0.22-micron filtration in the preparation of Tc-99m sulfur colloid substantially improves study quality and increases the diagnostic certainty in the identification of sentinel lymph nodes.

Female↗
PubMed1997

Prognosis in patients with left ventricular apical aneurysm diagnosed by thallium-201 or Tc-99m sestamibi SPECT images.

The prognosis of patients with left ventricular (LV) aneurysm diagnosed by thallium single-photon emission computed tomography (Tl-SPECT) or technetium-99m sestamibi SPECT (MIBI) has not previously been defined. Of 9,505 Tl or MIBI patients, 139 with apical infarct and probable LV aneurysm on tomographic images were identified. Patients were grouped by the presence of divergent versus parallel LV walls. Divergent walls show increasing separation of the walls as they approach the apex on vertical or horizontal long-axis slices. The degree of the deformation at the apex (divergent vs parallel walls), extent of impaired myocardium (total number of pixels in the defect/total number of pixels in the myocardium x 100%), percentage of reversibility, and segmental and total severity of standard deviations of perfusion defects were calculated. Seventy-six patients underwent contrast ventriculography. Patients with divergent walls (n = 57) were older (p = 0.05), had lower ejection fractions (p = 0.012), higher lung uptake (only Tl patients (p = 0.06), and more frequent ST elevation on the resting electrocardiogram (p = 0.009) than patients with nondivergent (parallel) walls. For both groups, the percent impaired myocardium was comparably high (44 +/- 9% vs 46 +/- 10%). Analysis of asynergic segments in 76 patients who underwent contrast ventriculography showed more akinetic, paradoxical, or aneurysmal segments in the apical region of the left ventricle in the group with SPECT divergent walls. Cox model analysis showed divergence as the significant correlate of death. At 5 years, survival for the group with divergent walls was 52% compared with 75% for those with nondivergent walls (p = 0.008). Despite significant apical LV impairment in both groups, mortality was almost twice as high in the group with divergent walls compared with patients with parallel walls. Thus, patients with LV aneurysm diagnosed by radionuclide SPECT perfusion imaging have a higher mortality when displaying a divergent wall pattern than patients with lesser deformity.

Aged↗
PubMed1997

Lymphoscintigraphy, the sentinel node concept, and the intraoperative gamma probe in melanoma, breast cancer, and other potential cancers.

There is a resurgence of interest in lymphoscintigraphy because of attention to the sentinel node concept and the availability of the surgical gamma probe that can be used in the operating room to localize radiolabeled sentinel nodes. Conventional surgical management of melanoma has been altered for intermediate thickness tumors such that lymph node dissection is performed for a lymph node bed only if the sentinel node is tumor positive on histological exam after gamma probe-guided excision. This approach is cost effective, saving about 80% of these patients (sentinel node tumor negative) the cost and morbidity of unnecessary "elective lymph node dissection." In addition, a biopsy can be performed on all lymph node beds that receive lymphatic drainage from the tumor site thereby improving staging and perhaps survival by providing the most appropriate therapy. Substantial work has been done to develop optimum imaging techniques and the best radiopharmaceutical preparation to achieve accurate, reproducible lymphatic drainage images. Our methodology includes the following intradermal injections of a technetium 99m sulfur colloid (modified preparation) are followed by dynamic imaging (10 seconds per frame); static imaging up to 30 minutes and late imaging at 1 to 2 hours. Images show lymphatic channels that lead to sentinel nodes in 1, 2, 3, or more anatomic locations. Surgical management is altered to include sampling sentinel nodes of nodal beds, many of which would not have been sampled by previous conventional surgical estimates of lymphatic drainage. While clinical success of lymphoscintigraphy and intraoperative probe localization of the sentinel node in melanoma is evident, use of lymphoscintigraphy and the sentinel node concept in breast cancer is investigative, but promising. The radiopharmaceutical is injected around the tumor in the breast followed by imaging to delineate lymphatic drainage to the sentinel node(s). Optimum methodologies for radiopharmaceutical, volume and/or activity of injectate, and imaging have yet to be determined. Breast lymphatic drainage can be to axilla, internal mammary, and/or supraclavicular nodes in any combination.

Breast Neoplasms↗
PubMed1996

The importance of work-up (verification) bias correction in assessing the accuracy of SPECT thallium-201 testing for the diagnosis of coronary artery disease.

Noninvasive testing is often evaluated by the sensitivity and specificity in comparison with a more invasive, but more definitive "gold" standard. However, work-up or verification bias, which occurs when the results of a noninvasive test impact the decision to perform the gold standard invasive test, increases the "observed" sensitivity and decreases the "observed" specificity of the noninvasive test. Most large clinical studies utilizing a noninvasive technique to diagnose coronary artery disease have biases, particularly work-up bias. To obtain more accurate measurements of sensitivity and specificity, we determined the observed sensitivity and specificity of stress (exercise and dipyridamole) single photon emission computed tomographic (SPECT) thallium testing for the detection of coronary artery disease by angiography, and then applied previously published equations to correct for work-up bias. From a computerized data base, reports of 4354 stress SPECT thallium studies from January 1, 1986 through December 31, 1992 were reviewed. All patients with a known history of myocardial infarction or prior coronary angiography were excluded, leaving 2688 patients. From this total, 471 patients underwent coronary angiography within 90 days following stress SPECT thallium testing. Coronary artery disease was defined as a visually assessed stenosis of a coronary artery or a major branch > 50%. Of the 2688 stress SPECT thallium studies, 1265 were normal and 1423 were abnormal. For the 471 patients who underwent catheterization within 90 days following stress SPECT thallium testing. the "observed" sensitivity and specificity were 98 and 14%, respectively. After correction for work-up bias, the corrected sensitivity and specificity were 82 +/- 6% and 59 +/- 2%, respectively. Most studies utilizing noninvasive technologies for the detection of coronary artery disease include patients with known coronary artery disease and have work-up bias as well. By knowing the thallium results of patients with and without catheterization, we were able to correct for work-up bias. These data provide better estimate of the sensitivity and specificity of stress SPECT thallium testing.

Bias↗
PubMed1996

Early stage melanoma: lymphoscintigraphy, reproducibility of sentinel node detection, and effectiveness of the intraoperative gamma probe.

PURPOSE: To assess the influence of lymphoscintigraphic and intraoperative gamma probe findings on the surgical management of melanoma and to test reproducibility of lymphoscintigraphic findings. MATERIALS AND METHODS: After lymphoscintigraphic identification of the sentinel node, intraoperative gamma probe localization and sentinel lymph node excision were performed in 25 patients. To assess reproducibility, 13 patients underwent lymphoscintigraphy twice within 2-17 days. A modified preparation of technetium-99m sulfur colloid with smaller particles than routinely obtained was injected intradermally around the lesion. Dynamic flow images were obtained at 10 seconds per frame followed by a series of static images obtained every 5 minutes for 30 minutes. RESULTS: A sentinel node was identified in all patients. In eight patients, multiple drainage pathways were seen and surgical management was changed. In 11 of the 13 who underwent lymphoscintigraphy twice, sentinel node identification was reproducible. CONCLUSION: Lymphoscintigraphy is reproducible in detection of the sentinel node and with the surgical probe helps effectively guide surgical management.

Female↗
PubMed1996

Thallium imaging in management of post-revascularization patients.

The role of myocardial perfusion imaging in the evaluation of post revascularization patients has not been well defined. Published data with special emphasis on the results from the Emory Angioplasty versus Surgery Trial (EAST) indicate that the frequency of adverse cardiac events (death, MI, repeat revascularization) following PTCA or CABG is equal in symptomatic and asymptomatic patients with ischemic thallium defects. Current American Heart Association Guidelines recommend radionuclide studies only in symptomatic patients. Recently reported data support the need for non invasive testing in asymptomatic as well as symptomatic patients at 1 year post-revascularization. Prognostic variables including transient and permanent left ventricular dilatation and thallium lung uptake in addition to stress perfusion defect reversibility on myocardial thallium SPECT scans are important prognostic indicators in post revascularization patients.

Angioplasty, Balloon, Coronary↗
PubMed1996

Technetium-99m-sulfur colloid for lymphoscintigraphy: effects of preparation parameters.

UNLABELLED: There has been a resurgence in the use of lymphoscintigraphy for the external detection of lymph nodes for metastatic melanoma and breast tumors. Technetium-99m-antimony trisulfide colloid was the radiopharmaceutical developed for this procedure and was found to have a narrow distribution of small particles, 0.003-0.03 microns, but it was never approved by the FDA. Technetium-99m-sulfur colloid also forms particles and this article reports on the effects different preparation parameters have on its particle size distribution and stability. METHODS: Four groups of kits were evaluated, kits which utilized: (a) a reduced heating protocol with a new 99mTc-elution, (b) a reduced heating protocol with an old 99mTc-elution, (c) a prolonged heating protocol with a new 99mTc-elution and (d) a prolonged heating protocol with an old 99mTc-elution. The particle size distribution and the stability of the different 99mTc-sulfur colloid kit preparations were evaluated over 6 hr utilizing polycarbonate filters ranging from 0.03 to 10 microns. RESULTS: In vitro studies demonstrated no significant change in the particle size distribution over a 6-hr period and all 99mTc-sulfur colloid preparations had a bimodal particle size distribution pattern. Importantly, heating the kit for shorter periods of times utilizing [99mTc]pertechnetate, which had a longer ingrowth of [99mTc]pertechnetate, produced a formulation which had the largest percentage of particles smaller than 0.03 microns. CONCLUSION: In our clinical setting, 99mTc-sulfur colloid prepared with the reduced heating protocol and utilizing [99mTc]pertechnetate, which has the highest ingrowth of [99mTc]pertechnetate has proved to be an excellent agent for lymphoscintigraphy studies. This preparation has demonstrated rapid movement of the particles from the primary site to the lymph nodes in over 97% (106/109) of the patients we have studied.

Humans↗
PubMed1995

Nuclear medicine.

Combined SPECT perfusion and PET fludeoxyglucose F 18 metabolic imaging is emerging as a method for determining appropriateness of revascularization. Fusion of SPECT images with images from computed tomography, magnetic resonance imaging, and PET is important for accurate localization of tumor foci, particularly for surgical decisions.

Humans↗
PubMed1995

Incorporation of right ventricular counts as a bullseye artifact.

Although extensive information regarding right ventricular uptake of thallium and a variety of bullseye artifacts exist, previous reports have not recognized a bullseye artifact due to right ventricular uptake of thallium. This case report again emphasizes the need for careful inspection of tomographic images while interpreting the bullseye. It is the first reported case of a bullseye artifact due to incorporation of right ventricular counts into the bullseye representation of left ventricular septal wall counts.

Aged↗
PubMed1995

Slowly progressive apraxia in Alzheimer's disease.

Slowly progressive apraxia due to Alzheimer's disease was encountered in a 66 year old, right handed man whose initial impairments included coordinated movements of the left hand and some features of the alien hand syndrome. Over four years, the patient developed progressively worsening deficits of memory and language. A biopsy of his right temporal lobe showed numerous plaques and neurofibrillary tangles. Pronounced right parietal lobe hypoperfusion on serial SPECT suggests involvement of this region in contralateral praxis.

Aged↗
PubMed1994

Left ventricular dilatation and multivessel coronary artery disease on thallium-201 SPECT are important prognostic indicators in patients with large defects in the left anterior descending distribution.

This study examines the importance of left ventricular (LV) dilatation, and evidence of multivessel coronary artery disease identified on thallium-201 (TI-201) single-photon emission computed tomographic (SPECT) scintigrams, for predicting long-term outcome in patients with an extensive left anterior descending (LAD) perfusion deficit. Impaired contractility of the left ventricle determined by low ejection fraction, elevated LV end-systolic volume, and dilatation of the left ventricle are known as major predictors of mortality after myocardial infarction. TI-201 single-photon emission computed tomography primarily reveals status of perfusion/redistribution, but also contains indirect information on LV function. To date, there are no TI-201 SPECT data on impaired function of the left ventricle (LV dilatation) and extent of perfusion deficits, discussed together as correlates of survival. Patient data were prospectively collected in the computer data base at Emory University. A large perfusion defect involving more than one third of the LAD territory was identified in 291 of 2,652 consecutive patients examined with TI-201 SPECT initial and 3-hour redistribution studies. Follow-up data were obtained for 284 patients (98%) at 38 +/- 14 months. Of the 291 patients, 58 died. The most powerful multivariate correlates of death were LV dilatation, multivessel disease, and the ratio of the LAD severity stress score to total severity of SDs stress score. Cox model analysis was used to determine correlates of survival. Three-year survival for patients with LV dilatation was 73% versus 89% without LV dilatation (p < 0.001). Three-year survival in patients with 1-vessel disease ("LAD only") was 94% versus 78% for multivessel disease (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Disease↗