CT screening for lung cancer Assessing a regimen's diagnostic performance
Department of Radiology, Weill Medical College of Cornell University, New York, NY 10021, USA. Clinical Imaging
(Impact Factor: 0.81).
The purpose of this study was to characterize the diagnostic performance of a regimen of CT screening for lung cancer.
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.
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%.
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.
Available from: Marie-Christine Woronoff-Lemsi
- "Thus, many of the SPNs were incidental findings on chest CT. In the radiology literature, studies of SPN have been developed in the context of lung cancer screening programs [20,21,26]. However, subjects who undergo lung cancer screening in most countries are selected on the basis of age, substantial smoking history, absence of serious co-morbid disease, and willingness to participate in all necessary follow-up imaging and intervention. "
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ABSTRACT: The process of diagnosis and management of solitary pulmonary nodules (SPNs) between 1 and 3 cm is not standardized. This multicentre study investigated how diagnosis of newly discovered SPNs is managed in routine practice.
We examined 11,515 radiology reports of patients undergoing chest computed tomography (CT) at all 76 radiology centres in 18 French administrative districts covering 8,220,000 people. Information on diagnostic procedures and treatment administered from discovery to definitive diagnosis of SPN was collected prospectively.
We identified 152 cases of newly diagnosed SPNs. Follow-up was complete for 112 patients. The median number of diagnostic tests was 4 and the mean time to diagnosis was 41.4 days. Marked variability was observed in the sequence of diagnostic tests, and 8 diagnostic pathways were identified. Patients' characteristics and radiological features of SPNs influenced the number of tests performed. Referral by specialist, history of smoking and spiculated SPN predicted the performance of at least one invasive procedure (P < 0.01). Definitive diagnosis was a malignant disease in 30 patients (26%).
The diagnosis of SPN is a complex process that physicians approach in markedly different ways. Implementing practice guidelines for managing the diagnosis of SPN requires clarification.
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ABSTRACT: It has been widely recognized that the oft-quoted randomized clinical trials (RCTs) of lung cancer screening by chest radiography--studies that were interpreted as showing no benefit--were seriously flawed. We begin by describing the shortcomings of these trials and presenting an analysis of the problems typically encountered in performing RCTs in this area. Screening for lung cancer using computed tomography (CT) has shown that CT offers great superiority over chest radiography in diagnosing small lung cancers in the three studies that performed both CT and chest radiography on all patients. The Early Lung Cancer Action Project (ELCAP), showed that false-positive results can be kept reasonably low and are much less common on repeat screening, and that CT screening can be managed with no notable excess of percutaneous or surgical biopsies when following a well-defined regimen of screening. This regimen details the parameters of the initial CT, the definition of a positive result, and the subsequent work-up of positive results. Following the updated International (I)-ELCAP protocol, it has been further found that (1) the frequency of positive results is low: 15% for the baseline cycle of screening and 6% for the subsequent cycles. (2) The frequency of screen-diagnoses as compared with all diagnoses is 97% or higher. (3) The relative frequency of presurgical Stage I is well over 80%; the median diameter of the screen-diagnosed cases on repeat screening is 8 mm (versus 15 mm at baseline screening). (4) A high percentage of the screen-diagnosed cases were genuine cancers which led to death if not treated. (5) The estimated 8-year cure rate for resected baseline screen-diagnosed lung cancers without evidence of lymph node metastases is 95% and for resected annual repeat cancers is 98%. (6) CT screening appears to be highly cost-effective. These preliminary results of CT screening suggests that the cure rate of screen-diagnosed lung cancer, using the I-ELCAP regimen of screening, may be over 70% as compared with that of usual care of 10% and that of chest radiographic screening of 20%.
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