Photodynamic therapy outcome modelling for patients with spinal metastases: a simulation-based study

Area of Science:

• Oncology
• Medical Physics
• Biomedical Engineering

Background:

• Spinal metastases significantly impact patient quality of life, necessitating effective treatments.
• Photodynamic therapy (PDT) offers a minimally invasive, non-thermal oncology treatment option.
• Predictive algorithms are crucial for optimizing PDT in spinal metastases and minimizing spinal cord damage.

Purpose of the Study:

• To present a framework for photodynamic therapy (PDT) modeling and planning for spinal metastases.
• To simulate the feasibility of BPD-MA mediated PDT for treating bone metastases at 690 nm and 565 nm wavelengths.
• To evaluate light diffuser configurations and power allocation for optimal tumor destruction versus spinal cord damage.

Main Methods:

• Utilized the open-source software PDT-SPACE for PDT planning and simulation.
• Simulated treatment on CT images from three patients with spinal metastases.
• Evaluated different light diffuser types (cut-end, cylindrical) and optimized power allocation.

Main Results:

• The 565 nm wavelength demonstrated potential to treat 90% of metastatic lesions with <17% spinal cord damage, but required infeasible treatment times.
• The 690 nm wavelength offered feasible treatment times but risked severe spinal cord damage when targeting 90% of the lesion.
• PDT-SPACE simulation platform can optimize PDT delivery for metastatic spine treatment.

Conclusions:

• This work provides a prospective methodology for analyzing PDT feasibility in spinal tumor ablation.
• Further preclinical studies are necessary to determine spinal cord damage extent and functional impairments.
• Clinical trials require comprehensive understanding of PDT dose-response and safety profiles.