# Evaluation of the Cellsway Microfluidic CTC Enrichment and Identification Platform for CTC Detection in Metastatic NSCLC

## TL;DR

This paper introduces a new microfluidic platform for efficiently isolating and identifying circulating tumor cells in non-small-cell lung cancer patients using a minimally invasive liquid biopsy approach.

## Contribution

The Cellsway platform uses inertial hydrodynamics for high-throughput, label-free CTC enrichment with high specificity and reproducibility.

## Key findings

- The platform achieved recovery rates of 91.9% for H1975 and 78.3% for A549 NSCLC cell lines in spiking experiments.
- CTCs were detected in 47% of stage IV NSCLC patients with a specificity of 95% at a cutoff of 1 CTC per 7.5 mL of blood.
- Patient-derived CTCs had smaller mean diameters than cultured cells but were effectively enriched using hydrodynamic tuning.

## Abstract

Lung cancer is the leading cause of cancer-related mortality worldwide, with non-small-cell lung cancer (NSCLC) accounting for the majority of cases. Standard tissue biopsies are invasive and unsuitable for repeated monitoring. Liquid biopsy technologies, particularly circulating tumor cell (CTC) analysis, offer a minimally invasive alternative for real-time disease tracking. To address the need for efficient and reproducible CTC isolation, we developed the Cellsway microfluidic CTC enrichment and identification platform, which employs inertial hydrodynamics in a spiral-shaped microfluidic channel comprising hydrofoil-shaped pillars to enable high-throughput, label-free enrichment of CTCs while preserving cell integrity, followed by an optimized CTC identification assay. Analytical performance assessed through spiking experiments using NSCLC cell lines demonstrated recovery rates of 91.9% for H1975 cells and 78.3% for A549 cells. Clinical validation was performed on blood samples from 51 stage IV NSCLC patients. A 7.5 mL volume of peripheral blood was processed with the SwayBox platform, and enriched CTCs were identified through an optimized multiplex immunofluorescence protocol. CTCs were detected in 47% of NSCLC patients, with counts ranging from 0 to 72 cells per 7.5 mL of blood. At a cutoff of 1 CTC per 7.5 mL, the assay achieved a specificity of 95%. Patient-derived CTCs exhibited smaller mean diameters compared to cultured NSCLC cell lines, yet were effectively enriched through hydro-dynamic tuning. These findings demonstrate that the Cellsway platform enables efficient and re-producible CTC isolation with high specificity, supporting its potential utility for clinical monitoring and precision oncology in NSCLC.