An Australian study presented at the 2019 ERS Congress has shown high levels of agreement between transbronchial lung cryobiopsy and surgical lung biopsy for ILD diagnosis.
Although cryobiopsy has already been adopted in many centres, the findings support its clinical utility as an alternative to surgery in patients requiring lung tissue for their ILD diagnosis.
The COLDICE study, published concurrently in The Lancet Respiratory Medicine, involved 65 patients across nine sites who each had the two procedures performed sequentially under a single general anaesthetic.
Dr Lauren Troy, from the Royal Prince Alfred Hospital and University of Sydney, told the Congress there was a high level of agreement – about 70% – between paired cryobiopsy and surgical lung biopsy specimens when reviewed for histopathological pattern.
De-identified clinical and radiological details from patients were also presented to a panel of experts who each formed their initial individual diagnosis and then reached consensus diagnosis.
The 130 tissue specimens were then added to the diagnostic process and again considered by the panel for final individual and consensus diagnosis.
The level of the agreement between paired samples was nearly 77%.
Just over half of the final diagnoses were idiopathic pulmonary fibrosis and about a quarter were hypersensitivity pneumonitis. The range of other diagnosis included small numbers of sarcoidosis, smoking-related ILD, connective tissue disease-ILD, lymphangioleiomyomatosis, unclassifiable ILD and non-ILD.
Dr Troy said when considering definite and high confidence diagnoses at multidisciplinary discussions (MDD), the agreement between cryobiopsy and surgical lung biopsy was excellent at 95%.
And in low confidence cases generated at MDD with cryobiopsy, the majority were still in agreement with surgical lung biopsies.
Of the eight discordant cases, only four were reclassified by the surgical lung biopsy to an alternative high confidence or definite diagnosis.
In the unclassifiable group on cryobiopsy only two were reclassified to an alternative high confidence diagnosis with surgical biopsy
“So if I could distill all of the study findings down to one sentence, it is that in this cohort, the larger tissue specimens generated by surgical biopsy really only added meaningful information to the diagnostic process in 1 in 10 patients,” she said.
Dr Troy said the due to the design of the study, they were unable to do a head to head analysis of safety endpoints but no new safety signals for cryobiopsy were observed.
Mild-to-moderate airway bleeding was observed in 22% of cryobiopsies but there were no cases of severe airway bleeding. There were two cases of acute exacerbation in IPF leading to one death.