First in human measurements of abscess cavity optical properties and methylene blue uptake prior to photodynamic therapy by in vivo diffuse reflectance spectroscopy.
J Biomed Opt
; 29(2): 027002, 2024 Feb.
Article
em En
| MEDLINE
| ID: mdl-38414658
ABSTRACT
Significance:
Efficacious photodynamic therapy (PDT) of abscess cavities requires personalized treatment planning. This relies on knowledge of abscess wall optical properties, which we report for the first time in human subjects.Aim:
The objective was to extract optical properties and photosensitizer concentration from spatially resolved diffuse reflectance measurements of abscess cavities prior to methylene blue (MB) PDT, as part of a phase 1 clinical trial.Approach:
Diffuse reflectance spectra were collected at the abscess wall of 13 human subjects using a custom fiber-optic probe and optical spectroscopy system, before and after MB administration. A Monte Carlo lookup table was used to extract optical properties.Results:
Pre-MB abscess wall absorption coefficients at 665 nm were 0.15±0.1 cm-1 (0.03 to 0.36 cm-1) and 10.74±15.81 cm-1 (0.08 to 49.3 cm-1) post-MB. Reduced scattering coefficients at 665 nm were 8.45±2.37 cm-1 (4.8 to 13.2 cm-1) and 5.6±2.26 cm-1 (1.6 to 9.9 cm-1) for pre-MB and post-MB, respectively. Oxygen saturations were found to be 58.83%±35.78% (5.6% to 100%) pre-MB and 36.29%±25.1% (0.0001% to 76.4%) post-MB. Determined MB concentrations were 71.83±108.22 µM (0 to 311 µM).Conclusions:
We observed substantial inter-subject variation in both native wall optical properties and MB uptake. This underscores the importance of making these measurements for patient-specific treatment planning.Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Fotoquimioterapia
/
Azul de Metileno
Limite:
Humans
Idioma:
En
Revista:
J Biomed Opt
Assunto da revista:
ENGENHARIA BIOMEDICA
/
OFTALMOLOGIA
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Estados Unidos