Novel hybrid cryo‐radial method: an emerging alternative to CT‐guided biopsy in suspected lung cancer. A prospective case series and description of technique

Abstract

In diagnosing peripheral pulmonary lesions (PPL), radial endobronchial ultrasound (R‐EBUS) is emerging as a safer method in comparison to CT‐guided biopsy. Despite the better safety profile, the yield of R‐EBUS remains lower (73%) than CT‐guided biopsy (90%) due to the smaller size of samples. We adopted a hybrid method by adding cryobiopsy via the R‐EBUS Guide Sheath (GS) to produce larger, non‐crushed samples to improve diagnostic capability and enhance molecular testing. We report six prospective patients who underwent this procedure in our institution. R‐EBUS samples were obtained via conventional sampling methods (needle aspiration, forceps biopsy, and cytology brush), followed by a cryobiopsy. An endobronchial blocker was placed near the planned area of biopsy in advance and inflated post‐biopsy to minimize the risk of bleeding in all patients. A chest X‐ray was performed 1 h post‐procedure. All the PPLs were visualized with R‐EBUS. The mean diameter of cryobiopsy samples was twice the size of forceps biopsy samples. In four patients, cryobiopsy samples were superior in size and the number of malignant cells per high power filed and was the preferred sample selected for mutation analysis and molecular testing. There was no pneumothorax or significant bleeding to report. Cryobiopsy samples were consistently larger and were the preferred samples for molecular testing, with an increase in the diagnostic yield and reduction in the need for repeat procedures, without hindering the marked safety profile of R‐EBUS. Using an endobronchial blocker improves the safety of this procedure.

The value of using radial endobronchial ultrasound to guide transbronchial lung cryobiopsy

“…Herath et al (8) described the RP-EBUS TBLC technique for peripheral pulmonary masses. The subsegmental locations of the mass were identified prior to the procedure and airways close to the lesion were marked as the point of placement of the radial probe within the lesion.…”

“…Chang et al (18) reported no complications from 11 patients (1-3 RP-EBUS TBLC per patient), Rodas et al (24) described three moderate bleeds in ten patients, Torky et al (25) reported seven moderate bleeding for 22 patients and Herath et al reported no complications for six patients with unknown number of passes (8). Herath et al (8) got larger, non-crushed samples to improve diagnostic capability and enhance molecular testing. RP-EBUS samples were obtained via conventional sampling methods (needle aspiration, forceps biopsy, and cytology brush), followed by a cryobiopsy.…”

Safety and Usefulness of Cryobiopsy and Stamp Cytology for the Diagnosis of Peripheral Pulmonary Lesions

“…Accordingly, we anticipated that it would be useful for the immunohistochemical and molecular analysis of peripheral pulmonary lesions (PPLs), which are common in NSCLC. However, reports on the use and safety of this technique for the diagnosis of PPLs are few [15,16,17,18]. Furthermore, the collection of multiple samples via CB, which is not possible with FB, can present high risks and may be technologically difficult.…”

Diagnostic Yield of Combined Pulmonary Cryobiopsies and Electromagnetic Navigation in Small Pulmonary Nodules

“…On the other hand, the size of tissue samples obtained with standard forceps usually limits the diagnostic yield in small nodules especially in the era of immunohistochemical and molecular testing required for lung cancer targeted therapies [5]. Transbronchial lung cryobiopsy (TBLC) is an emerging technique that allows tissue samples larger than those obtained with standard TBB in the setting of interstitial lung diseases [6, 7] and has been shown to be feasible under EBUS guidance in the setting of pulmonary nodules [8, 9]. We thus hypothesized that TBLC could perform better than TBB in the workup of nodules smaller than 2 cm in diameter.…”