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Biomedical subjects

David F Yankelevitz

Publications and source records attributed to David F Yankelevitz.

36 records · Page 2Linked to original sources
PubMed2003

CT screening for lung cancer.

The Early Lung Cancer Action Project (ELCAP) recently demonstrated that earlier diagnosis of lung cancer can be achieved with CT, and these results have led to considerable demand for CT screening. The advisability of screening seems obvious, as screening has been shown to provide for lung cancer treatment at a relatively early stage, leading to a better chance to avert death from lung cancer than when treatment is prompted by symptoms and/or signs. There are, however, countervailing ideas that CT lung cancer screening has not yet been demonstrated to 'save lives.' Further, it has been stated that CT screening has a notable problem of "overdiagnosis," meaning that screening finds lesions that are not life threatening, leading to unnecessary surgery. These concerns have led to the argument that assessing 'lives saved,' as well as the effects of overdiagnosis, can only be achieved with a randomized, controlled trial comparing CT screening with no screening, using a mortality endpoint. To this end, the National Lung Screening Trial (NLST) has been funded. This randomized, controlled trial is the most expensive screening study ever proposed. It compares CT screening with chest X-ray screening, and its designers envision that it will provide an answer about the benefit of CT screening, or lack thereof, in about 10 years. We do not question the value of the randomized design of 'treatment' trials for comparing competing interventions (treatments), but we have serious concerns about the use of randomization in the evaluation of a diagnostic test, such as CT. We feel that randomization is not necessary for evaluating a diagnostic test and may generate misleading results. Rather, we feel that the desired information is how often and how early is the disease diagnosed using that test. The purpose of this article is to raise the general level of concern about the underpinnings of such randomized 'screening' trials, and to convey some of the evidence that led to our pessimism about the NLST.

Female↗
PubMed2003

Evaluation of screening for a cancer: annotated catechism of the Gold Standard creed.

Even non-scientific people are generally aware of, and commonly also personally affected by, the confusion and debates that arose from two recent systematic reviews and their associated meta-analyses of the published randomized controlled trials (RCTs) that had been designed to assess the usefulness of screening for breast cancer. With nothing about the principles of research on cancer screening learned from this debacle, an RCT on screening for lung cancer has just been launched in the same 'gold standard' framework; and so in about 10 years, and upon expenditure of hundreds of millions of dollars, we are said to be able to learn whether the screening saves lives and whether it thereby is justifiable as a matter of public policy. We here examine the core tenets and precepts in this 'gold standard' line of thinking, and we argue that they are matters of belief at variance with the dictates of reason.

Bias↗
PubMed2003

Computerized tomography screening for lung cancer: new findings and diagnostic work-up.

On computerized tomography (CT) screening for lung cancer within the Early Lung Cancer Action Project, both at baseline and repeat screening, we found not only solid but also subsolid nodules, which unlike solid ones do not completely obscure the lung parenchyma. We established that subsolid nodules represent approximately 20% of the nodules shown on screening and that they have a higher frequency of malignancy than solid nodules. Although we found growth of solid nodules to be a reliable indicator of malignancy, growth of subsolid nodules was more difficult to assess. On review of our results to date in screening, we have continued to refine our definition of a positive result of screening from that given in our initial publication on screening. We have also provided an updated screening regimen. It starts with the initial, low-dose CT test and for all those with positive results on this initial test, the regimen continues by specifying the work-up needed to rule-in a diagnosis of malignancy. In this regimen, we found growth assessed by high-resolution CT to be a useful indicator of malignancy and have developed image-processing tools to help in this assessment. Once growth is ascertained, we recommend fine-needle aspiration for confirmation of malignancy. It may be that once criteria for definitive growth are established and validated, fine-needle aspiration may become optional. However, in the meantime, in the context of screening, a more cautious approach is warranted.

Humans↗
PubMed2003

Three-dimensional segmentation and growth-rate estimation of small pulmonary nodules in helical CT images.

Small pulmonary nodules are a common radiographic finding that presents an important diagnostic challenge in contemporary medicine. While pulmonary nodules are the major radiographic indicator of lung cancer, they may also be signs of a variety of benign conditions. Measurement of nodule growth rate over time has been shown to be the most promising tool in distinguishing malignant from nonmalignant pulmonary nodules. In this paper, we describe three-dimensional (3-D) methods for the segmentation, analysis, and characterization of small pulmonary nodules imaged using computed tomography (CT). Methods for the isotropic resampling of anisotropic CT data are discussed. 3-D intensity and morphology-based segmentation algorithms are discussed for several classes of nodules. New models and methods for volumetric growth characterization based on longitudinal CT studies are developed. The results of segmentation and growth characterization methods based on in vivo studies are described. The methods presented are promising in their ability to distinguish malignant from nonmalignant pulmonary nodules and represent the first such system in clinical use.

Algorithms↗
PubMed2002

Mammographic screening: no reliable supporting evidence?

Much confusion is being generated by the conclusion of a recent review that "there is no reliable evidence that screening for breast cancer reduces mortality." In that review, however, there was no appreciation of the appropriate mortality-related measure of screening's usefulness; and correspondingly, there was no estimation of the magnitude of this measure. We take this measure to be the proportional reduction in case-fatality rate, and studied its magnitude on the basis of the only valid and otherwise suitable trial. We found reliable evidence of fatality reduction, apparently substantial in magnitude.

Breast Neoplasms↗
PubMed2002

Computed tomography screening for lung cancer.

The development of CT technology reopened the lung cancer screening debate. Computed tomography screening for lung cancer certainly meets all the criteria required for an appropriate screening test. First and perhaps most importantly, the disease for which the screening is being performed should have a significant prevalence in the population being studied and be a significant health risk for those afflicted with it. Lung cancer is the leading cause of cancer death in both men and women, and one of the most lethal of all cancers.

Adenocarcinoma↗
PubMed2002

CT screening for lung cancer: frequency and significance of part-solid and nonsolid nodules.

OBJECTIVE: In the Early Lung Cancer Action Project (ELCAP), we found not only solid but also part-solid and nonsolid nodules in patients at both baseline and repeat CT screening for lung cancer. We report the frequency and significance of part-solid and nonsolid nodules in comparison with solid nodules. MATERIALS AND METHODS: We reviewed all instances of a positive finding in patients at baseline (from one to six noncalcified nodules) and annual repeat screenings (from one to six newly detected noncalcified nodules with interim growth) to classify each of the nodules as solid, part-solid, or nonsolid. We defined a solid nodule as a nodule that completely obscures the entire lung parenchyma within it. Part-solid nodules are those having sections that are solid in this sense, and nonsolid nodules are those with no solid parts. Chi-square statistics were used to test for differences in the malignancy rates. RESULTS: Among the 233 instances of positive results at baseline screening, 44 (19%) involved a part-solid or nonsolid largest nodule (16 part-solid and 28 nonsolid). Among these 44 cases of positive findings, malignancy was diagnosed in 15 (34%) as opposed to a 7% malignancy rate for solid nodules (p = 0.000001). The malignancy rate for part-solid nodules was 63% (10/16), and the rate for nonsolid nodules was 18% (5/28). Even after standardizing for nodule size, the malignancy rate was significantly higher for part-solid nodules than for either solid ones (p = 0.004) or nonsolid ones (p = 0.03). The malignancy type in the part-solid or nonsolid nodules was predominantly bronchioloalveolar carcinoma or adenocarcinoma with bronchioloalveolar features, contrasting with other subtypes of adenocarcinoma found in the solid nodules (p = 0.0001). At annual repeat screenings, only 30 instances of positive test results have been obtained; seven of these involved part-solid or nonsolid nodules. CONCLUSION: In CT screening for lung cancer, the detected nodule commonly is either only part-solid or nonsolid, but such a nodule is more likely to be malignant than a solid one, even when nodule size is taken into account.

Aged↗
PubMedDate not supplied

CT screening for lung cancer Assessing a regimen's diagnostic performance.

PURPOSE: The purpose of this study was to characterize the diagnostic performance of a regimen of CT screening for lung cancer. METHODS: Using a common protocol/regimen of screening, 2968 asymptomatic persons at high risk for lung cancer were enrolled in two studies [Early Lung Cancer Action Projects (ELCAP) I and II] for baseline and annual repeat screening. A total of 4538 annual repeat screenings were performed. The regimen's diagnostic performance was characterized in terms of frequency of positive result of the initial CT as well as of screen-diagnosis and Stage I screen-diagnosis among all diagnoses (interim-diagnoses included), all separately for baseline and annual repeat screenings. RESULTS: The proportions with positive result of the initial CT were 12% and 6% in the baseline and repeat screenings, respectively. The proportions of screen-diagnoses among all diagnoses (interim-diagnoses included) were 97% and 99% in the baseline and repeat cycles, respectively. The corresponding proportions of pre-surgical Stage I screen-diagnoses were 95% and 93%. CONCLUSION: The performance of the ELCAP regimen is quite satisfactory in avoiding over many positive results of the initial CT, and it produces highly promising diagnostic results as for the attainment of cure by early intervention.

Aged↗
PubMedDate not supplied

CT screening for lung cancer: significance of diagnoses in its baseline cycle.

PURPOSE: The aim of this study was to assess the significance of Stage I diagnoses of lung cancer in the baseline cycle of screening for this disease, with special reference to the potential for overdiagnosis. METHODS: We reviewed all 69 cases of Stage I lung cancer diagnosis resulting from our baseline CT screening. Among these 69 cases of lung cancer, 24 presented as solid, 30 as part-solid, and 15 as nonsolid nodules. The extent to which these represented genuine malignancy was assessed by a panel of experts on lung pathology, and the "aggressiveness" of these cases was addressed by the criterion of the tumor's volume doubling time being less than 400 days. RESULTS: The expert panel confirmed all 69 cases as representing genuine malignancy. Among the 69 cases without evidence of metastases, the proportion that satisfied the aggressiveness criterion was 60/69=87%. The corresponding proportions by presentation as solid, part-solid, and nonsolid nodule were 23/24 (96%), 27/30 (90%), and 10/15 (67%), respectively. CONCLUSIONS: In baseline CT screening for lung cancer, overdiagnosis of the disease is uncommon, with cases presenting as a nonsolid nodule a possible exception to this.

False Positive Reactions↗
PubMedDate not supplied

Frequency of coronary artery calcification on low-dose computed tomography screening for lung cancer.

PURPOSE: The purpose of this study was to determine the frequency of coronary artery calcification (CAC) in high-risk people undergoing computed tomography (CT) screening for lung cancer. METHODS: Between 1999 and 2004, we performed CT screening for lung cancer on 4250 participants, all without documented prior cardiovascular disease, using multidetector-row (MD) CT. Of the patients, 1102 underwent imaging with a four-detector-row CT at 120 kVp and 40 mA, with pitch 1.5 and collimation of 2.5 mm in a single breath hold of 15-20 seconds, and 3148 did with an eight-detector-row CT at the same kVp, mA, and pitch settings but with collimation of 1.25 mm. Visualized CACs in each coronary artery (main, left anterior descending, circumflex, and right) were scored separately as 0 (absent), 1 (mild), 2 (moderate), or 3 (severe), yielding a possible score of 0-12 for each person. Frequency distributions by gender, age, and pack-years of smoking were determined. Odds ratios (ORs) were calculated using logistic regression analysis of the prevalence of CAC as a joint function of gender, age, pack-years of smoking, and presence of diabetes. RESULTS: Among the subjects younger than 50 years, positive CAC scores were three times more frequent for men than for women (22% vs. 7%); among those older than 50 years, the frequency increased for both men and women but the increase for women was greater than that for men. The frequency of positive CAC scores increased with increasing pack-years of smoking; it was always higher for men than for women. The ORs were 2.6 for male gender (P<.0001), 3.7 and 9.6 for ages 60-69 years and 70 years or older, respectively, for increasing age (P<.0001 for both), 1.6 and 2.3 for 30-59 pack-years and 60 pack-years or longer, respectively, for increasing pack-years of smoking (P<.0001 for both), and 1.6 for having diabetes (P=.016). CONCLUSION: The CAC score can be derived from ungated low-dose MDCT images. This information can contribute to risk stratification and management of coronary artery disease.

Adult↗
PubMedDate not supplied

Bronchioloalveolar carcinoma and adenocarcinoma with bronchioloalveolar features presenting as ground-glass opacities on CT.

OBJECTIVE: As bronchioloalveolar carcinoma (BAC) is noninvasive but, in its later stages, has a worse prognosis than adenocarcinoma with bronchioloalveolar features (ACB), early identification and differentiation is important for therapeutic and prognostic purposes. We wanted to identify features of BAC, which differentiated it from ACB when both presented as ground-glass opacities (GGOs) on CT. MATERIALS AND METHODS: We reviewed all pathologic specimens of patients who were diagnosed with BAC and ACB in the lung from 1991 to 1999 in our institution and whose malignancy presented as a GGO on CT. This yielded 29 patients, 15 with BAC and 14 with ACB with GGOs on CT. Both univariate frequency table and multivariate logistic regression approaches were used to analyze the CT characteristics of these GGOs (location, GGO pattern, size, shape, margin, presence and type of air bronchogram and pseudocavitation). RESULTS: BAC most frequently had a "GGO halo" around a solid opacity, often was a GGO "mixed with consolidation" with the smallest BACs being "pure GGO." Air bronchograms were frequently present in the largest GGOs. Pseudocavitations were rare. ACB, on the other hand, most frequently presented as a GGO "mixed with consolidation," less frequently with a "GGO halo" and rarely with "superimposed lymphangitis." The air bronchograms, frequently present, were usually tortuous and ectatic. Pseudocavitation was present in about one-third of the cases. The most useful CT features of GGO in separating those due to BAC from those due to ACB were pure (uniform) ground-glass attenuation and absence of lymphangitis. CONCLUSION: The CT features of BAC and ACB presenting as GGO reflect the histologic descriptions of these carcinomas.

Adenocarcinoma↗
PubMedDate not supplied

Percutaneous needle biopsy in single lung patients.

The occurrence of complications such as pneumothorax after a transthoracic needle biopsy is well known. This event may be life threatening in patients with a single aerated lung, thus altering the risk/benefit assessment of the physician when considering whether to attempt an otherwise indicated biopsy. We review our results in 6 single-lung patients who underwent a transthoracic needle biopsy for pulmonary nodules.

Aged↗
PubMedDate not supplied

CT screening for lung cancer: the first ten years.

This article reviews the current state of knowledge regarding computed tomography (CT) screening for lung cancer. The initial 3 studies have demonstrated the superiority of CT-based screening for lung cancer over traditional radiography. Furthermore, false-positive tests common on baseline screening were manageable without notable excess of biopsies or thoracotomies. Differences and similarities of various screening regimens are discussed in relation to reported study results. When comparing the various studies, the focus should be placed on the diagnostic distribution achieved under annual repeat screening, as it is this distribution which is obtained year after year of repeat screening and this distribution and the curability of these repeat screen-diagnosed lung cancer which determine the usefulness of the screening regimen. To date, these studies demonstrate a consistent shift to over 80% of the cancer being diagnosed in Stage IA. This marked shift suggest that the curability of screen-detected lung cancers will be markedly improved.

Follow-Up Studies↗