Non-invasive measurements of tumor mechanical forces using fiber Bragg grating sensors

Area of Science:

• * Biomedical Engineering
• * Cancer Research
• * Biomechanics

Background:

• * Mechanical forces significantly influence solid tumor progression, invasion, and treatment response.
• * Current methods for quantifying tumor mechanical forces are invasive and rely on indirect estimations via mathematical modeling.
• * There is a need for direct, non-invasive techniques to measure in vivo tumor mechanics.

Purpose of the Study:

• * To introduce a novel non-invasive method for in vivo measurement of macroscopic mechanical forces in solid tumors and surrounding tissues.
• * To reconstruct 2D spatial force distributions without mathematical modeling.
• * To provide a clinically translatable framework for longitudinal monitoring of tumor mechanics.

Main Methods:

• * Development of a multi-sensor tactile imaging system utilizing fiber Bragg grating sensors (FBGs).
• * Application of the system to orthotopic 4T1 and E0771 murine breast tumor models at four progression time points.
• * Quantification of forces and reconstruction of 2D spatial force distributions in tumor and normal tissue.

Main Results:

• * Successful quantification of mechanical forces in both tumor and surrounding normal tissue.
• * Reconstruction of spatial force distributions revealing heterogeneous mechanical responses.
• * Higher force levels detected at tumor sites, correlating with tumor volume and stiffness, consistent with computational predictions.

Conclusions:

• * The developed FBG-based tactile imaging system offers a direct, non-invasive method for in vivo tumor force measurement.
• * This technique provides a clinically translatable strategy for studying tumor mechanobiology.
• * Findings support the role of solid-stress accumulation in growing tumors and offer potential for improved cancer diagnosis and therapy monitoring.