Sensor technology advancement enhancing exhaled breath portability: Device set up and pilot test in the longitudinal study of lung cancer

Abstract

User-friendliness of exhaled breath sampling procedure and portability of the collected samples are strategic key-points for disease monitoring in unstructured environments. These issues have been addressed by collecting exhaled breath on adsorbing cartridges; many samplers on cartridge have been used in clinical experiments through exhalate collection, including our patented Pneumopipe (European patent 12425057.2). Increasing the operative functionality of the sampling device enhances collection effectiveness and the representativity of the specimen. These features become of paramount importance when a minimal amount of disease needs to be detected with preventive approach in screening and follow-up. The primary endpoint was aimed at achieving Pneumopipe optimization (Pneumopipe II). The secondary endpoint was to investigate through a pilot longitudinal study focused on monitoring recurrence after lung cancer surgical resection and the evolution of the breath fingerprint before and after surgery. A quartz crystal-based gas sensor array, named BIONOTE-V was used to measure the breath fingerprint. Cross-validated Partial Least Square Discriminant Analysis and Principal component analysis were used to study the time evolution of the breath fingerprint before and after surgery. Thirty-five patients had the breath fingerprint collected before and after surgery, with fifteen having at least two more measurements for each timepoint (at least two before and two after surgery). (Primary endpoint) At isoprene lab tests, Pneumopipe has shown to preserve its effectiveness in collecting volatile mixture in a representative sample. (Secondary endpoint) Cancer recurrence was observed in 8 patients. Postoperative breath fingerprint detected lung cancer recurrence with an accuracy of 91 %, a sensitivity of 75 %, a specificity of 96 %, a PPV of 86 % and a NPV of 93 %. Effectiveness of exhalate collection and portability of the sampler are preserved with Pneumopipe II.