Yuko Nakamura1, Marcelino Bernardo1, Tadanobu Nagaya1, Kazuhide Sato1, Toshiko Harada1, Peter L. Choyke1, and Hisataka Kobayashi1
Near infrared photoimmunotherapy (NIR-PIT) is a new
cancer treatment that combines the specificity of antibodies for targeting
tumors with the toxicity induced by photon absorbers after irradiation with NIR
light.
The purpose of this study was to determine if MR imaging can detect changes in
the MR properties of tumor within several hours of NIR-PIT in an animal model. Prolongation of T2, reductions in apparent
diffusion coefficient (ADC) and increased enhancement using gadofosveset
are seen within 2 hours of NIR-PIT treatment of tumors. Thus, MRI can be a
useful imaging biomarker for detecting early therapeutic changes after NIR-PIT.