SESSION TITLE: Lung Cancer Posters I
SESSION TYPE: Original Investigation Poster
PRESENTED ON: Wednesday, October 29, 2014 at 01:30 PM - 02:30 PM
PURPOSE: Novel multi-functional nanoparticles, porphysomes, have shown preferable accumulation in tumors after systemic administration and local photothermal tumor destruction using low-powered laser irradiation. The aim of this study is to optimize porphysome-enhanced photothermal therapy (PTT) of lung cancer for clinical translation.
METHODS: Both straight-cut and diffusing type laser fibers were used and compared. Porphysome-containing phantoms (90µg/g, 45µg/g, and control) were created and irradiated using either a 250 mW, 500 mW, or 750mW powered 670 nm diode laser for 10 minutes to reveal heat energy transmission within the phantoms using a thermal camera (n=3 in each). The concentration of 90µg/g came from the previous in vivo biodistribution in a rabbit VX2 lung tumor. The phantom dosimetry was validated in an orhtotopic rabbit VX2 lung tumor model, which was ablated transpleurally or transbronchially 48 hours post-porphysome injection using the aforementioned laser fibers (diffusing type at 500mW, and a straight-cut at 250mW, and 500mW). The viability of the tumor tissue was assessed by NADH metabolic activity staining.
RESULTS: The laser light was more effectively absorbed by higher porphysome concentrations in the phantoms. The phantoms with 90µg/g porphysomes showed a more than 20 degree temperature increase, which lead to cancer cell death regardless of the laser power. Both the fibers showed successful photothermal ablation of porphysome-containing lung tumors with significant difference in the ablated tissue volume when compared to control tumors and porphysome-containing lung parenchyma. The control rabbit demonstrated minimal ablation using the diffusing type fiber, however, the straight-cut fiber produced a small ablation volume due to the heat of the fiber itself.
CONCLUSIONS: Porphysome-enhanced PTT showed selective tumor destruction with less damage to the normal lung using both fiber types, in particular when using the diffusing type fiber. The diffusing type fiber appeared to be more practical than the straight-cut fiber for treating larger volumes while avoiding local tissue heating.
CLINICAL IMPLICATIONS: Porphysome-enhanced PTT is promising in the rabbit, and can be clinically translated into lung cancer treatment.
DISCLOSURE: The following authors have nothing to disclose: Hironobu Wada, Cheng Jin, Kentaro Hirohashi, Patrick McVeigh, Spencer Hu, Tatsuya Kato, Amir Khan, Takashi Anayama, Brian Wilson, Gang Zheng, Ichiro Yoshino, Kazuhiro Yasufuku
I will present about the development of photothermal therapy using systemic porphysome injection and low-powered laser irradiation.