Tissue-mimicking phantom of liver with tunable optical properties for laser thermotherapy

Abstract

Laser ablation is a modern minimally invasive therapy technique used to treating tumors of the liver, kidneys, pancreas, brain, prostate, and skin 1–3. However, the efficiency of the procedure critically depends on precise tuning of irradiation parameters, exposure duration, and cooling conditions4-7. Although animal models are frequently employed for protocol testing, they present limitations — including tissue heterogeneity, mismatched optical properties relative to human tissues, and ethical concerns8 ¬¬¬— which reduce reproducibility and complicate clinical translation.
As an alternative, tissue-mimicking phantoms (TMPs) are utilized to replicate key optical, thermal, and mechanical properties of biological tissues. These phantoms are employed for device calibration, specialist training, and optimization of ablation protocols9-13. Nevertheless, current TMPs still exhibit significant shortcomings. For instance, agar- and gelatin-based phantoms degrade at temperatures exceeding 100 °C14, polyacrylamide phantoms contain toxic acrylamide monomers 15, and models based on polyvinyl alcohol or carrageenan fail to achieve the required combination of biocompatibility, thermal stability, and optical fidelity16. Consequently, no universal phantom currently exists that can accurately replicate the behavior of both healthy and pathological tissues under clinically relevant laser wavelengths.

In this study, we propose a novel sodium alginate-based TMP modified with Cu²⁺ ions and ovalbumin. Alginate provides high thermal stability (up to 200 °C) and biocompatibility; CuSO₄ enables tunable mechanical stiffness and optical absorption; and ovalbumin contributes to light scattering and mimics protein coagulation dynamics. The developed phantom successfully replicates the optical and density characteristics of liver tissue and, under irradiation with an Nd:YAG laser (1064 nm), produces ablation and coagulation zones comparable to those observed in ex vivo liver samples. These results confirm its suitability for optimizing laser ablation parameters and developing clinical protocols.

This work was supported by the Russian Science Foundation (Project № 25-79-30006).

Speaker

Mirzaeva Sophia
Prokhorov General Physics Institute of the Russian Academy of Sciences
Russia

Discussion

Ask question