Abstract P2-05-02: Optical Parameters of Breast Cancer before and after Chemotherapy

Objectives: To analyze optical parameters of cancer before and after chemotherapy in breast cancer patients.Patients and Methods: Absorption coefficient (µa) and reduced scattering coefficient (µs9) of cancer and contra-lateral normal region before and after chemotherapy were measured by using TRS-20SH (Hamamatsu Photonics K.K.). A pulsed laser of 760, 800, and 830 nm wave-length was irradiated at multiple sites in both breasts with time-resolved spectroscopy method and scattered light was analyzed by photon diffusion equation. A total of ten breast cancer patients who underwent neoadjuvant chemotherapy participated in the trial. Written informed consent was obtained from all of the patients.Results: Absorption coefficient (µa, 1/cm) of breast cancer was significantly higher than that of contra-lateral normal region before chemotherapy. In 800 nm wave-length, absorption coefficient of breast cancer decreased significantly after chemotherapy (before:0.0927, after;0.0498, p=0.002). Although absorption coefficient of contra-lateral normal region also decreased (before:0.0561, after;0.0437, p=0.006), cancer showed more significant decrease than contra-lateral normal region (cancer:-43.1%, normal region;-19.0%, P Figure 1. Absorption coefficient (p a , cm-1), at 800rim (cancer-normal) Similar results were observed in 760 and 830 nm wave-length. There was no difference in reduced scattering coefficient (µs9) between before and after chemotherapy in both breast cancer and contra-lateral normal region. Conclusion: The absorption coefficient of cancer was significantly higher than that of contra-lateral normal region before chemotherapy and decreased significantly after chemotherapy. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-05-02.