Supplementary Material for: Diagnosis of peripheral pulmonary lesions using forceps and 1.1 or 1.7 mm cryoprobes. A randomised trial.

Introduction: Lung cancer screening has increased the detection of peripheral pulmonary lesions (PPLs). Accurate diagnosis for therapy and prognosis is crucial but challenging. Our study compares the safety and efficacy of transbronchial cryobiopsy with two probe diameters and forceps biopsy.
Methods: This single-centre, investigator-initiated, open-label, randomised trial included patients with PPLs who required flexible bronchoscopy with radial endobronchial ultrasound-guided biopsy for histopathological diagnosis. Patients received a forceps biopsy and were randomly assigned to a cryobiopsy with a 1.1 mm (freezing time 7-10 sec) or a 1.7mm cryoprobe (freezing time 4-6 sec), respectively. The primary outcome was the diagnostic yield; secondary outcomes included total biopsy size, the proportion of malignant tissue, artefact-free alveolar space percentage, molecular pathology of the specimen and safety.
Results: Fifty-four patients (66.52±9.81 years; 48.1% male) with a median nodule size of 24mm [IQR 19 to 30] were included. The overall diagnostic yield was similar in the 1.1 mm and 1.7 mm groups (75.9% vs. 88.0%, p=0.261), and the specimens obtained with the two different cryoprobes were equal in size, quality, and information about molecular pathology. There was no difference in procedural-related bleeding between the groups (p=0.847). Compared to forceps biopsies, cryobiopsies had a superior overall diagnostic yield (75.9% vs. 48.1%, p=0.001) and were better suited for further molecular analysis (p=0.001).
Conclusion: The 1.1 mm and 1.7 mm cryoprobes displayed comparable diagnostic yield, ability to provide molecular pathology information, and safety. Forceps biopsy was inferior to cryobiopsy in all aspects except safety.