Obtaining a tissue sample to diagnose a PPL suspected of cancerous origin is of utmost
importance. The current gold standard; Transthoracic CT guided needle biopsy approach with a
success rate of >90% comes at the expense of an increased side effect profile.
Given that most lung cancers originate in the bronchus, hence named "bronchogenic carcinoma",
it would be rational to think that endobronchial route should provide the best route of
sampling with the least amount of side effects. Radial EBUS has become popular during the
last decade as an endobronchial modality in diagnosing PPL with minimal side effects.
However, the yield is still not satisfactory in comparison to CT guided biopsy with only 73%
success rate in a meta-analysis. There is also with wide variation in different centres.
Use of a new biopsy method called cryo-biopsy using the R-EBUS guide sheath may bridge the
gap and increase the diagnostic yield of PPL.
Cryo biopsy had been proven to give larger sample sizes and reduced crush artefact compared
to the conventional radial EBUS biopsies.
However, there have been no head to head trials comparing Cryo-probe biopsy vs. the gold
standard: CT guided biopsy.
Cryo-biopsy has very favourable side effect profile without any pneumothorax occurrence. If
the yield were to be non-inferior to CT guided biopsy this would certainly be the preferred
choice of biopsy for PPL in the future.
Methodology All patients with a PPL requiring a diagnostic biopsy will be eligible for
recruitment to the trial. The recruited patients will be randomly allocated to either CT
guided core biopsy or radial EBUS guided cryobiopsy.
Study design Multi centre intervetional,randomised control trial.
Patients diagnosed with a PPL that requires a biopsy.
If the patient is randomised to the cryo biopsy arm:
The procedure will be done under the usual guidelines and practice of the centre as for a
flexible bronchoscopy procedure.
Once flexible bronchoscopy is introduced the pre-determined desired segment, the R-EBUS is
inserted covered by the GS.
Once the R EBUS locates the lesion, the GS is left in situ and the USS probe is retracted.
The cryoprobe is then inserted through the GS to the desired location. Flexible Cryoprobe
(outer diameter 1.9mm) will be applied for 4 seconds for each biopsy. The cryogen gas used
will be Co2.
The probe will be retracted together with the GS and the bronchoscope en masse after each
biopsy. A minimum of 1 and maximum of 3 samples will be taken.
A CXR is taken within 1 hour post procedure to access for pneumothorax. Adverse events during
the procedure will be recorded. If a chest tube placement, other investigations due to side
effects or overnight hospital stay were to be required; all costs will be calculated
retrospectively. Minor bleeding will not be considered an additional cost as this occurs with
If the patient is randomised to the CT biopsy arm:
A CT guided core biopsy will be performed as per usual practice of that centre. 2-6 passes
will be performed for each PPL.
A CXR 1hour post procedure will be performed to assess for pneumothorax or procedure related
If a chest tube placement, other investigations due to side effects or overnight hospital
stay were to be required all costs will be calculated retrospectively.
At the pathology:
All samples will be assessed for the size of the sample and the suitability for molecular
testing. An independent pathologist will assess samples.
For both procedures: Both direct and indirect costs will be calculated. The main aim of cost
analysis is to calculate the cost of side effect management in each arm to determine the most
cost-effective method of sampling a PPL.