Departments: Interventional Pulmonology in Other Journals
Standard Pleural Biopsy Versus CT-Guided Cutting-Needle Biopsy for Diagnosis of Malignant Disease in Pleural Effusions: A Randomised Controlled Trial
Lancet. 2003;361:1326–1330. Maskell NA, Gleeson FV, Davies RJ. Respiratory Trials Unit, Oxford Centre for Respiratory Medicine, Churchill Hospital, Oxford Radcliffe NHS Trust, Oxford.
This prospective, parallel, randomized trial of 50 consecutive patients with cytologically negative suspected malignant pleural effusions was designed to assess whether computed tomography (CT)-guided biopsy is an improvement over standard pleural biopsy. Inclusion criteria for the trial included: 1) unilateral pleural effusion with clinical suspicion of malignant pleural disease, and 2) at least one negative pleural fluid cytology. Exclusion criteria were: 1) bilateral pleural effusions; 2) transudative pleural effusions (pleural fluid protein <35 g/dL) associated with heart failure or hypoalbuminemia such that the clinical prior probability of a hydrostatic effusion was high; 3) any pleural fluid cytology positive for malignant cells; 4) bleeding diathesis sufficient to make pleural biopsy unusually hazardous; 5) inability to give informed consent; and 6) age <18 years. All patients had a contrast-enhanced thoracic CT scan to assess pleural thickening. Patients were randomly allocated, stratified by baseline pleural thickening, to either Abrams' pleural biopsy (n = 25) or CT-guided cutting-needle biopsy (n = 25). Sensitivity for pleural malignancy from the biopsy specimen was the primary end point, with the patient's clinical outcome after 1 year being the diagnostic gold standard. Abrams' needle obtained 4 to 6 biopsy specimens from the upper surface of the rib below the entry site. The CT-guided procedure generally required only one biopsy pass, but a second pass was done if the initial sample was deemed macroscopically unsatisfactory, and no more than 2 biopsy passes were made in any patient. Of the 50 patients, 3 did not undergo biopsy. Pleural tissue for histologic analysis was obtained in all 23 patients who underwent CT-guided biopsy and in 23 of 24 undergoing Abrams' biopsy. Abrams' biopsy correctly diagnosed malignancy in 8 of 17 patients (sensitivity 47%, specificity 100%, negative predictive value 44%, and positive predictive value 100%). CT-guided biopsy correctly diagnosed malignancy in 13 of 15 (sensitivity 87%, specificity 100%, negative predictive value 80%, positive predictive value 100%; difference in sensitivity between Abrams' and CT-guided 40%, 95% confidence interval 10–69, P = 0.02). The diagnosis of malignant mesothelioma was made in 19 patients (8 CT-guided biopsy group and 11 in the Abrams' biopsy group). Thus, the diagnostic advantage was similar in patients proving to have mesothelioma. No complications were reported in the group receiving CT-guided biopsy, and one moderate-sized subcutaneous hematoma was seen in the Abrams' biopsy group (needing conservative treatment only). The authors interpreted these results to indicate that the primary use of CT-guided biopsy would avoid doing at least one Abrams' biopsy for every 2.5 CT-guided biopsies, and in cytology-negative suspected malignant pleural effusions, CT-guided pleural biopsy is a better diagnostic test than Abrams' pleural biopsy. Considering that over 200,000 malignant pleural effusions occur in the United States (175,000) and the United Kingdom (40,000) annually, it is important to identify the best diagnostic method to document malignant pleural effusion. Large-scale studies have shown that cytologic analysis of pleural fluid is able to diagnose malignancy in approximately 60% of malignant effusions. Even the addition of closed-needle pleural biopsy adds only a slight increase (7–25%) in the diagnostic yield (Mayo Clin Proc. 1985;60:158–164). In patients with malignant mesothelioma, the pleural fluid cytology yields the diagnosis in less than 40% of patients (Chest. 1997;111:106–109; Br J Cancer. 1999;79:666–672). Therefore, pleural biopsy might have a better role in the diagnosis malignant mesothelioma. Closed pleural biopsy, without CT guidance, can be performed using Abrams' needle, Cope needle, Raja needle, or other modifications. CT-guided needle biopsy uses different needles. Observational studies with nonrandomized groups of patients have shown that CT-guided needle biopsy provides a diagnostic sensitivity of approximately 80% in documenting pleural malignancy. However, the study by Maskell and associates is the first trial to compare the diagnostic yields between Abrams' needle biopsy and CT-guided needle biopsy. These authors have shown that CT-guided pleural biopsy is more effective than standard Abrams' biopsy in the diagnosis of malignant pleural disease (87% vs. 47%, respectively). To reiterate the learning point of the study, CT-guided biopsy as the initial procedure would avoid doing repeated biopsy in 40% of patients compared with current practice, equating to one avoided biopsy procedure for every 2.5 CT-guided procedures done. Although thoracoscopy and thoracotomy are the more definitive procedures to obtain larger samples of pleural specimens for analysis, consideration should be given to CT-guided needle biopsy so that more invasive procedures can be obviated.