A randomised controlled study on SuperDimension versus fluoroscopy guided lung cryobiopsies.

<bold>BACKGROUND:</bold> When performing transbronchial cryobiopsies (TBCB) in the diagnostic setup for interstitial lung diseases, most centres use fluoroscopic guidance to find the most optimal placement for the probe, preferably in close proximity to the thoracic wall. This can be difficult when the biopsies are taken from posterior or dorsal parts, as fluoroscopy will not show if the probe is located close to pleura. Also, if the affected areas are limited to smaller areas, the precision of where to place the probe can be difficult. In this study, we compared using an electromagnetic navigation system, superDimension (SD), to conventional fluoroscopy when performing TBCB in areas difficult to reach. <bold>Methods:</bold> In this randomised controlled study, patients having TBCB performed from areas difficult to reach were randomised to either SD or conventional fluoroscopy guided TBCB. Frequency of pneumothorax and bleeding, and diagnostic yield was registrered. Final diagnosis was made at MDT where participants were blinded to the biopsy method used. <bold>Results:</bold> The results are based on an interim analysis including 21 patients (SD: 11, fluoroscopy: 10). There was no significant difference in rate of pneumothorax, or mild or moderate haemorrhage in the two groups. Diagnostic yield for TBCB was 70% in the fluoroscopy group and 91 % in the SD group (p=0.22). After MDT, one patient in the SD group (9%) and two patients in the fluoroscopy group were still unclassifiable (20%). This was not statistically significant (p=0.48). <bold>CONCLUSION:</bold> For selected patients, using SD for the TBCB procedure might increase the diagnostic yield. Complication rates were similar. A larger trial is required to investigate this further.