Role of computed tomographic scanning of the thorax prior to bronchoscopy in the investigation of suspected lung cancer

Background-Fibreoptic bronchoscopy (FOB) is the usual initial investigation of choice in patients with suspected endobronchial carcinoma, but it is of ten nondiagnostic. Once a positive diagnosis has been made, many patients u ndergo staging by computed tomographic (CT) scanning to assess the extent o f the disease and its suitability for radical treatment. To determine wheth er initial CT scanning before FOB is a cost effective way of reducing subse quent unnecessary or unhelpful invasive diagnostic procedures, a study was undertaken in 171 patients with suspected endobronchial carcinoma. Methods-A randomised two group study was performed with all patients underg oing an initial CT staging scan. In group A the CT scans were reviewed befo re FOB, allowing cancellation or a change to an alternative invasive proced ure if considered appropriate. In group B all patients proceeded to FOB wit h the bronchoscopist blinded to the result of the CT scan until after the p rocedure. Results-In group A six of 90 patients (7%) required no further investigatio ns as the CT scan was either normal, consistent with benign disease, or con sistent with widespread metastatic disease. Of the remainder, bronchoscopy was diagnostic in 50 of 68 (73%) in group A compared with 44 of 81 (54%) in group B (p = 0.015). Overall, a positive diagnosis was made after a single invasive investigation in 64 of 84 patients (76%) in group A compared with only 45 of 81 patients (55%) in group B (p = 0.005). Only seven of 90 pati ents (8%) in group A required more than one invasive investigation compared with 15 of 81 patients (18.5%) in group B. In patients with malignancy, br onchoscopy was more likely to be diagnostic in group A (50 of 56 patients ( 89%)) than in group B (44 of 62 (71%); p = 0.012), and the diagnosis was mo re frequently made on the initial invasive investigation (group A, 63 of 70 (90%); group B, 44 of 62 (71%); p = 0.004). Because of the lower number of invasive procedures performed in group A than in group B, the cost of perf orming CT scans before FOB in all patients in group A would have equated to a projected cost of performing CT scans in 60% of patients after FOB in gr oup B. Conclusions-Performing initial CT thoracic scans before bronchoscopy in pat ients with suspected endobronchial malignancy is a cost effective way of im proving diagnostic yield from invasive diagnostic procedures and occasional ly may obviate the need for any further investigation.