Study design in the evaluation of breast cancer imaging technologies.

RATIONALE AND OBJECTIVES: Bringing a new imaging technology to market is a complex process. Beyond conceptualization and proof of concept, obtaining U.S. Food and Drug Administration (FDA) approval for clinical use depends on the documented experimental establishment of safety and efficacy. In turn, safety and efficacy are evaluated in the context of the intended use of the technology. The purpose of this study was to examine a conceptual framework for technology development and evaluation, focusing on new breast imaging technologies as a highly visible and current case in point. MATERIALS AND METHODS: The FDA views technology development in terms of a preclinical and four clinical phases of assessment. With a concept of research and development as a learning model, this phased-assessment concept of regulatory review against intended use was integrated with a five-level version of a hierarchy-of-efficacy framework for evaluating imaging technologies. Study design and analysis issues are presented in this context, as are approaches to supporting expanded clinical indications and new intended uses after a new technology is marketed. CONCLUSION: Breast imaging technologies may be intended for use as replacements for standard-of-care technologies, as adjuncts, or as complementary technologies. Study designs must be appropriate to establish claims of superiority or equivalence to the standard for the intended use. Screening technologies are ultimately judged on their demonstrated effectiveness in decreasing cause-specific mortality through early detection, but they may be brought to market for other uses on the basis of lesser standards of efficacy (eg, sensitivity, specificity, positive and negative predictive value, and stage of disease detected).

Colposcopy, cervicography, speculoscopy and endoscopy. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial.

ISSUES: The colposcope was developed in 1925 and is well established in clinical gynecologic practice for defining and delineating cytologically detected lesions mainly of the cervix but also the vagina and vulva. Additionally, various endoscopic procedures in gastroenterology, pulmonary and urologic lesions enhance the cytologic detection and histologic verification of precancerous and cancerous lesions. The cost-effectiveness of all these devices and their applicability, particularly in countries with a limited health budget, is a major issue. This task force considered aspects of the present state of the art and the challenges in the 21st century. CONSENSUS POSITION: Automated cytology can interface with colposcopic examination in a number of significant ways. Automated cytologic analysis of conventional cervical smears can potentially direct colposcopic examination by predicting the nature of a lesion, assist in determining which patients should receive colposcopy and, in some settings, thereby reduce the number of colposcopies. Potentially, various combinations of automated cytology and colposcopy may be used to generate screening protocols that might result in more effective and inexpensive screening. The role of cervicography, or high-resolution cervical photography, as a screening device remains to be defined. Sensitivity for high grade lesions is generally no greater than that in cytology, and specificity appears lower. The interpretation of cervical photographs in triage of mildly abnormal cytology may prove to be useful in countries with established cytology programs. In areas of the world where cytology screening programs are not in place, the interpretation of cervical photographs may have its most dramatic effect. Cost-effectiveness analyses are needed. There are, at present, insufficient data for the evaluation of speculoscopy, a procedure using chemiluminescent illumination of the cervix for visualization of acetowhite areas. Basic training in colposcopy should be integrated into the residency programs of obstetrics and gynecology. Criteria for the adequate training of colposcopists should be developed. Continuing education programs in colposcopy should be developed when they are not already in existence. The cost-effectiveness of integrating colposcopy as a primary screening technique should be evaluated. Following a high-grade squamous intraepithelial lesion (HSIL) cytology result, colposcopically directed punch biopsy should be taken with or without endocervical curettage. This generally should precede the loop electrosurgical excision procedure (LEEP); however, in certain circumstances direct LEEP may be indicated. LEEP under colposcopic vision is an efficient way to treat an HSIL lesion of the cervix because the histologic extent and margins can be determined, unlike with laser surgery or cryosurgery. It is also more cost-effective than cold knife conization because general anesthesia and an operating room are unnecessary. Following LEEP, the endocervical canal should be examined colposcopically for any evidence of involvement. Lesions in the endocervix can then be removed with a different-shaped loop. Further research into Raman spectroscopy as a diagnostic aid in cervical pathology is needed, as is the use of micrococolpohysteroscopy for in vivo cytologic analyses, especially of the endocervical canal and transformation zone. Hysteroscopy is the most direct method for the diagnosis and treatment of intrauterine diseases. Hysteroscopic endometrial biopsy is more accurate than conventional biopsy methods. Cervical invasion of endometrial cancer can be detected by hysteroscopy. The depth of invasion, however, is more accurately determined by magnetic resonance imaging or computed tomography. ONGOING ISSUES: Many topics for ongoing research and/or implementation are mentioned under "Consensus Position," above. (ABSTRACT TRUNCATED)

Cell preparation methods and criteria for sample adequacy. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial.

ISSUES: Cell Preparation Methods Standardized fixation and optimal staining Sampling of cervix, sampling error, homogenization of sample, subsampling Assessment of liquid-based preparations: efficacy and economic impact Training and transitional procedures before full implementation of new technologies Criteria for Sample Adequacy Clinician responsibility for collecting and providing representative sample to laboratory Collection instruments, number of slides Cellular content of samples: evidence of transformation zone (TZ) sampling, number of squamous cells present, obscuring factors Screening issues CONSENSUS POSITION The conventional cervical smear remains the standard method of cervical cancer screening but has limitations in individual test sensitivity and specificity. Sample takers should: (1) receive appropriate training in sample collection, (2) be held responsible for providing the laboratory with appropriate samples, and (3) have their performance monitored. The instruments used for sampling should collect cells from both the ectocervix and endocervix; optimally, TZ sampling, represented by the presence of endocervical or squamous metaplastic cells, should be identifiable in samples other than atrophic specimens. The adequacy of a specimen (as judged microscopically) does not guarantee that it is representative of the cervix. Each cytology report should include a comment on cellular content/adequacy of the specimen. Liquid-based preparations may overcome many of the inherent problems with the conventional cervical smear. ONGOING ISSUES: We need further data on the cost-effectiveness of making two slides from cervical specimens and/or using two samplers rather than a single one. Do we have enough information to make recommendations as to the appropriate type of sampler to be used in particular situations, such as routine screening? What is the best method of screening for/detecting endocervical glandular neoplasia? How are such terms as unsatisfactory and inadequate defined in cervical cytology classifications other than the Bethesda System? What number and types of epithelial cells should be present (visualized) in a cervical smear or liquid-based preparation for it to be considered adequate? Do we need to have evidence of TZ sampling in specimens taken during the follow-up period after treatment of squamous intraepithelial lesion or after detection of endocervical glandular neoplasia? What criteria for obscuring factors, such as blood and inflammation, should be used in assessing adequacy? Cost-benefit analyses of utilizing liquid-based preparations are needed. Should we inform women about the technical details of the test methods available or chosen by the laboratory? Are women in a position to decide which method is the most appropriate to assess their cervical scrape sample? We need to obtain more information about the properties of proprietary liquid fixative/transport media with respect to inactivation of viral pathogens, tuberculosis and other bacterial pathogens and suitability for immunobiologic and molecular tests, etc. We need to obtain more information on the use of stoichiometric stains and the limitations of Papanicolaou stain for image analysis systems. The use of liquid-based preparations for nongynecologic cytopathology and ancillary tests must be considered, including criteria for adequacy. We need to obtain more information on the time required for and best methods of training experienced cytotechnologists to become competent at assessing liquid-based cervical preparations.

Computerized screening devices and performance assessment: development of a policy towards automation. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial.

ISSUES: The extension of automation to the diagnostic assessment of clinical materials raises issues of professional responsibility, on the part of both the medical professional and designer of the device. The International Academy of Cytology (IAC) and other professional cytology societies should develop a policy towards automation in the diagnostic assessment of clinical cytologic materials. CONSENSUS POSITION: The following summarizes the discussion of the initial position statement at the International Expert Conference on Diagnostic Cytology Towards the 21st Century, Hawaii, June 1997. 1. The professional in charge of a clinical cytopathology laboratory continues to bear the ultimate medical responsibility for diagnostic decisions made at the facility, whether automated devices are involved or not. 2. The introduction of automated procedures into clinical cytology should under no circumstances lead to a lowering of standards of performance. A prime objective of any guidelines should be to ensure that an automated procedure, in principle, does not expose any patient to new risks, nor should it increase already-existing, inherent risks. 3. Automated devices should provide capabilities for the medical professional to conduct periodic tests of the appropriate performance of the device. 4. Supervisory personnel should continue visual quality control screening of a certain percentage of slides dismissed at primary screening as within normal limits (WNL), even when automated procedures are employed in the laboratory. 5. Specifications for the design of primary screening devices for the detection of cervical cancer issued by the IAC in 1984 were reaffirmed. 6. The setting of numeric performance criteria is the proper charge of regulatory agencies, which also have the power of enforcement. 7. Human expert verification of results represents the "gold standard" at this time. Performance characteristics of computerized cytology devices should be determined by adherence to defined and well-considered protocols. Manufacturers should not claim a new standard of care; this is the responsibility of the medical community and professional groups. 8. Cytology professionals should support the development of procedures that bring about an improvement in diagnostic decision making. Advances in technology should be adopted if they can help solve problems in clinical cytology. The introduction of automated procedures into diagnostic decision making should take place strictly under the supervision and with the active participation and critical evaluation by the professional cytology community. ONGOING ISSUES: Guidelines should be developed for the communication of technical information about the performance of automated screening devices by the IAC to governmental agencies and national societies. Also, guidelines are necessary for the official communication of IAC concerns to industry, medicolegal entities and the media. Procedures and guidelines for the evaluation of studies pertaining to the performance of automated devices, performance metrics and definitions for evaluation criteria should be established.

Quality assurance/control issues. International Academy of Cytology Task Force summary. Diagnostic Cytology Towards the 21st Century: An International Expert Conference and Tutorial.

ISSUES: General definitions of quality assurance and quality control (QA/C) have existed in many forms for decades, and a new discipline guides their application to diverse industrial and recently medical processes without much fanfare. However, in the field of cervical cytology screening, the range of QA/C options has recently broadened and become controversial. With the advent of new systems of terminology, larger-scale laboratories and new technologies--plus strong governmental and legal pressures in some nations--the range of extremely difficult and sometimes expensive QA/C choices our community faces is greater than ever. CONSENSUS POSITION: At our conference, the basic definitions of QA/C posed little difficulty. Presentation of the range of methods in use today and of those based on new technologies where use is proposed or has just begun also was achieved with little or no dispute. However, there was lack of consensus on exactly how QA/C methods are to be assessed. Indeed, there was little consistency in the use of different outcome measures with which we can judge success or failure of specific QA/C options. In addition, the tension between pressure to adopt sometimes uncertain or expensive method enhancements and pressure to maintain affordability and the widest possible access for populations that most need cervical cytology screening is greater than ever. ONGOING ISSUES: More data are required that would enable assessment of QA/C options with the clearest possible understanding of cost/benefits and current or new assumptions of risk. Other task forces, such as medicolegal, cost/benefit and those devoted to new technologies, are our essential partners in meeting the challenges described above.

Necrotizing arteritis in uncorrected tetralogy of Fallot with pulmonary artery.

A 10-year-old girl with uncorrected tetralogy of Fallot with pulmonary atresia presented with fevers of unknown origin and left lung infiltrates. At autopsy, necrotizing vascular changes resembling those of severe pulmonary hypertension (grade VI in the Health-Edwards classification) were confined to the left lung. Pulmonary blood flow and pressure were greater in the left lung and were provided by an enlarged collateral artery arising directly from the descending thoracic aorta. To our knowledge, this is the first report of necrotizing arteritis of the pulmonary arteries in uncorrected tetralogy of Fallot with pulmonary atresia.

Effect of aging on aortic morphology in populations with high and low prevalence of hypertension and atherosclerosis. Comparison between occidental and Chinese communities.

A comparative morphologic study of aortic changes with aging was conducted in different populations in an attempt to separate the effects of hypertension and atherosclerosis. Chinese and the occidental populations were chosen, as they are known to have a high prevalence of hypertension and atherosclerosis, respectively. Aortic tissue was collected from occidental (American and Australian) and Chinese populations from three geographic locations. Postmortem specimens were obtained from four fixed locations: ascending aorta (A), descending thoracic aorta (B), and abdominal aorta (suprarenal [C] and above the aortic bifurcation [D]). Histologic sections were used to measure aortic circumference, medial thickness, intimal thickness, and grade of atherosclerosis. Kidney sections were used to confirm the presence or absence of hypertension. A total of 302 cases (age range, 19 to 104 years; Male-to-female ration, 2:1) were studied: 112 Americans, 80 Australians, and 110 Chinese. Cases were divided into three age groups: 19 to 44; 45 to 64; and 65 years and older. The aortic circumference progressively decreased from sites A to D in all populations and age groups. The aortic circumference increased with age, and the increase was independent of the aortic location. When the populations were separated, however, the greater increase was at location A in the Chinese (P = .008) and locations D in the occidental (P = .13), a population contrast that was significant only in location A. Intimal thickness increased with advancing age and was maximal in the abdominal aorta. The population differences also were significant for intimal thickness and were significantly greater in the occidental population in B, C, and D locations, whereas for atherosclerosis significance was only seen in location D. Hypertension (as defined by the morphologic changes in the kidney) after adjusting for age, height, and weight resulted in no statistical significant effect on aortic circumference or on intimal thickness, but did show a significant increase in atherosclerosis score at locations B, C, and D. Also after adjusting for age, height, and weight, the Chinese had a significantly larger aortic circumference in location A compared with the occidental population, whereas in location D the occidentals with hypertension had a significantly larger circumference compared with Chinese, probably due to an interaction of atherosclerosis and hypertension. After similar adjustments, the medial thickness in locations A and C, the intimal thickness in B, C, and D, and atherosclerosis score in D were significantly greater in occidental than Chinese populations.(ABSTRACT TRUNCATED AT 400 WORDS)

Serial sectioning and multiple level examination of endomyocardial biopsies for the diagnosis of myocarditis.

To determine if serial sectioning and multiple level evaluation increase the sensitivity of endomyocardial biopsy for the detection of myocarditis, we prospectively studied all diagnostic endomyocardial biopsies between 1986 and 1989. Biopsies were embedded in paraffin, serially sectioned, and every 4-microns section was mounted in ribbons on glass slides. Every fifth slide was stained with hematoxylin and eosin and examined for myocarditis by the Dallas criteria (myocyte necrosis and inflammatory cells). Of a total of 153 biopsies, 20 cases (13%) were diagnostic of myocarditis on at least one section. Four biopsies (25%) were positive at slide Level 1, and 15 (75%) by slide Level 5; in five cases (25%), diagnostic foci were present only at or after slide Level 10. Multiple levels should be performed in the histologic evaluation of endomyocardial biopsies to increase the sensitivity of endomyocardial biopsy in the evaluation of myocarditis.

Percutaneous transluminal coronary angioplasty guidewire-induced coronary artery dissection without balloon inflation.

A case of arterial dissection of the right coronary artery secondary to angioplasty guidewire manipulation is presented. No balloon inflation was performed. The histologic appearance of the involved arterial segment was similar to that found in the left anterior descending coronary artery, which had undergone successful balloon dilatation. Both arteries demonstrated medial disruption and fibrointimal proliferation. The pathologic features of angioplasty-induced vascular injury may occur with or without balloon inflation.

Eosinophilic products lead to myocardial damage.

Eosinophils have been associated with endomyocardial fibrosis. However, their effect on the myocardium and the reactions they elicit have not been emphasized. We describe four patients with extensive myocardial eosinophilic infiltration with and without endomyocardial fibrosis. Patients with a short duration of disease had eosinophilic infiltrates, myocardial eosinophilic abscesses containing granular eosinophilic material, and/or Charcot-Leyden crystals with and without profuse histiocytic and giant cell reaction with granuloma formation. In the early phase, the granular eosinophilic material can be visualized by the Luna stain and/or by electron microscopic examination. In patients with a long duration of symptoms, well-developed granulomas and profuse fibrosis are seen and eosinophilic material may not be visualized. Toxic eosinophil granular protein may be involved in the development of these lesions.

Recently diagnosed idiopathic dilated cardiomyopathy: incidence of myocarditis and efficacy of prednisone therapy.

Fifty-two patients with recently diagnosed idiopathic dilated cardiomyopathy were studied to determine the incidence of myocarditis; patients were randomly assigned to receive either conventional therapy alone or conventional therapy plus prednisone to assess possible therapeutic efficacy with regard to survival. Inflammatory criteria were present in 23% of the population studied with 13% having overt myocarditis according to the Dallas criteria. The addition of prednisone to conventional therapy did not improve survival in a homogeneous population with new-onset dilated cardiomyopathy. Furthermore, the diagnosis of myocarditis by endomyocardial biopsy did not influence 2-year survival once dilated cardiomyopathy had developed. Biopsy-documented myocarditis resolved in all patients, according to results of 3-month follow-up endomyocardial biopsies, regardless of treatment group. There was a trend for patients with a left ventricular ejection fraction less than 20% to show reduced survival at 2 years compared to the group with a higher ejection fraction (p = 0.07). Right ventricular dysfunction determined at catheterization was present in 20 of 52 patients and was the most significant predictor of survival. Patients with preserved right ventricular function had a 95% 24-month survival rate compared to 47% for patients with right ventricular diastolic dysfunction (right ventricular end-diastolic pressure greater than or equal to 11 mm Hg) (p = 0.005).

Ventricular/vascular coupling and regional arterial dynamics in the chronically hypertensive baboon: correlation with cardiovascular structural adaptation.

Ventricular/vascular coupling dynamics and regional hemodynamics of five hypertensive baboons with concentric left ventricular (LV) hypertrophy (mean arterial pressure +/- SD, 148 +/- 16 mm Hg; LV mass/body weight ratio 3.42 +/- 0.8) were compared with five normotensive controls (mean arterial pressure 89 +/- 3 mm Hg; LV mass/body wt ratio 2.73 +/- 0.5) at different mean arterial pressures. Ventricular/vascular dynamics were assessed by aortic input impedance, pulsatile/total power ratio, effective arterial elastance and compliance from a three-element Windkessel "lumped" model of the circulation. Regional arterial dynamics were assessed by pulse-wave velocities and local reflection coefficients. Systemic arterial compliance was similarly decreased with elevated pressure in both groups but was significantly more reduced for the hypertensive group compared with control animals at control (0.49 +/- 0.16 vs. 0.96 +/- 0.09 ml/mm Hg; p less than 0.05) and acutely lowered arterial pressure (0.62 +/- 0.26 vs. 1.41 +/- 0.24 ml/mm Hg, respectively). Changes in compliance were paralleled by differences in effective arterial elastance derived from cineventriculographic pressure-volume ratios. Regional foot-foot and apparent phase pulse-wave velocities were significantly increased for distal aortic segments of the hypertensive animals during elevated pressures compared with controls (cff, 17.5 +/- 7.5 vs. 8.7 +/- 3.0 m/sec; p less than 0.05). Histology of the aorta revealed significant increases in collagen content (microgram/mg dry wt) from proximal to distal aortic segments (27 +/- 2 vs. 38 +/- 6; p less than 0.005) in hypertensive animals but not in controls (27 +/- 2 vs. 32 +/- 6; NS). With pharmacological normalization of systemic arterial pressures, hypertensive baboons developed aortic wave speeds similar to controls but manifested significantly reduced compliance compared with controls. In contrast, with acute elevations of pressure, systemic arterial aortic compliances were similar for both groups, but distal pulse-wave velocities were significantly increased for hypertensive animals compared with controls. We conclude that measures of ventricular/vascular coupling and arterial dynamics are determined by both the level of arterial pressure and the physical characteristics of the cardiovascular system in chronic systemic hypertension and pressure overload ventricular hypertrophy.

Early and late healing responses of normal canine artery to excimer laser irradiation.

Acute in vitro histologic studies have shown that the pulsed xenon chloride excimer laser causes precise microablation without the surrounding thermal tissue injury associated with frequently used continuous-wave lasers such as the argon, carbon dioxide, and neodymium:yttrium aluminum garnet lasers. However, the in vivo healing response of artery wall to excimer laser injury is not known. Accordingly, a xenon chloride excimer laser (308 nm, 40 nsec pulse width, 39 mJ/mm2/pulse) was transmitted via a 600 micron fused silica fiber to create 420 craters of varying depths (30 to 270 micron) in 21 normal canine femoral and carotid arteries. At 2 hours, 2 days, 10 days, and 42 days after excimer laser ablation, the artery segments were perfusion fixed in situ and analyzed by light, scanning, and transmission electron microscopy. At 2 hours, craters were covered by a carpet of platelets and entrapped red blood cells. Fibrin and exposed collagen fibers were seen at the crater base. There was a sharp demarcation of the crater-artery wall interface without lateral laser tissue injury. At 2 days, adherent platelets persisted with thrombus covering the base of the craters. Early healing responses were present, consisting of polymorphonucleated leukocytes and new endothelial cells, which extended over the crater rims. At 10 days, no thrombi were seen, and healing continued with almost complete reendothelialization. Macrophages, fibroblasts, fibrin, and entrapped red blood cells were present below the reendothelialized surface. At 42 days, healing was complete with obliteration of the craters by fibrointimal ingrowth. The surface was completely covered by a smooth monolayer of axially aligned endothelial cells. There were no aneurysms or surface hyperplastic responses. These favorable healing responses in normal canine arteries suggest that pulsed lasers with high tissue absorption coefficients, such as the xenon chloride excimer laser, may be suitable energy sources for clinical laser angioplasty procedures. However, further studies in atherosclerotic animals are required before human clinical responses can be accurately predicted.

Cardiovascular effects of cocaine: an autopsy study of 40 patients.

From September 1983 through November 1986, autopsies were performed on 6810 patients at the Office of the Maryland Medical Examiners; of these 40 had detectable cocaine, its metabolites, or both in body fluids. These patients were divided into two groups: natural cocaine-associated deaths (31 patients, mean age 28 +/- 5 years, blood level of cocaine 5.3 +/- 8.1 mg/L) and homicide deaths with detectable cocaine (nine patients, mean age 33 +/- 8 years, blood level of cocaine 0.3 +/- 0.3 mg/L). Cocaine-associated deaths were compared to a control group of 27 victims of sudden traumatic death (mean age 34 +/- 5 years). Total thrombotic occlusion of the left anterior descending coronary artery overlying mild coronary atherosclerosis occurred in one patient with cocaine-associated death. Results of histologic examination showed myocarditis (mononuclear infiltrate) in 8 of 40 (20%) patients dying with detectable cocaine in body fluids compared to 1 of 27 victims of sudden traumatic death (3.7%, p less than or equal to 0.05). Contraction band necrosis occurred in 25% of cocaine-associated deaths compared to a 41% incidence among victims of sudden traumatic death. We conclude that myocarditis occurs frequently in patients dying of cocaine abuse and may represent microvascular injury.

Prevalent myocarditis at necropsy in the acquired immunodeficiency syndrome.

The prevalence of myocarditis was retrospectively evaluated in 71 consecutive necropsy patients who died from acquired immunodeficiency syndrome (AIDS) between 1982 and 1986. Myocarditis was found in 37 cases (52%). Biventricular dilation at necropsy was present in seven cases (10%) and was accompanied by myocarditis in each case; fatal congestive heart failure occurred in four of these seven cases. Although viral, protozoan, bacterial, fungal and mycobacterial opportunistic pathogens were present in myocardial sections of 7 of 37 myocarditis cases, the etiology of myocarditis in the majority of these patients with AIDS remained idiopathic. Thus, myocarditis is a frequent finding at necropsy in patients with AIDS and may contribute to the development of biventricular dilation.

Coronary artery atherosclerosis revisited in Korean war combat casualties.

To confirm earlier studies of a high prevalence of coronary atherosclerosis in combat casualties of the Korean and Vietnam wars, we examined previously uncut coronary arteries from the hearts of 94 American male combat casualties (mean age, 20.5 years) from the Korean War using computerized planimetry and microscopic evaluation. Six (6.4%) men had severe atherosclerosis (75% to 90% cross-sectional area luminal narrowing) in one or more coronary arteries; five of the six had fibrous plaques, and one had a complicated plaque. Our prevalence is similar to that reported previously (5%). Therefore, to determine whether the decrease in the incidence of severe coronary atherosclerosis today is the result of decreased plaque formation in the young, we will need to examine at least 772 men to detect a 50% decline with 85% to 90% confidence.