Primary studies that evaluated radial probe endobronchial ultrasound for diagnosis of peripheral pulmonary lesions in at least 30 patients and that confirmed the diagnosis by histology or close clinical follow-up of at least six months were eligible for inclusion.
Most included studies were prospective cohorts; retrospective audits and randomised controlled trials were included. In most studies, patient selection was based on referral for diagnosis of peripheral pulmonary lesions. Studies also included patients based on peripheral pulmonary lesions not visible at routine bronchoscopy, patients with peripheral pulmonary lesions less than 20mm with computed tomography and patients with confirmed lung cancer. Reference standards included histology by alternate means, surgical resection, radiologic surveillance and follow-up. Prevalence of malignancy across studies was 72%. Mean age, where reported, ranged from 46 to 72 years. Some studies used additional guidance devices.
Two reviewers independently assessed studies for inclusion. Disagreements were resolved through consensus.