We constructed a small prototype system to demonstrate proof-of-principle for OPAL applications in oncologic procedures. A white light-emitting diode (LED) light source (KL200 LED, Leica, Buffalo Grove, Illinois) provided illumination continuously during all procedures. Excitation light for fluorescence was provided by high power 760-nm LED (M780L2 and LEDD1B, Thorlabs, Maryland) with band-pass filter (FF01-769/41, Semrock, Rochester, New York). A 0.33-MP monochrome complementary metal-oxide semiconductor (CMOS) camera (Firefly MV FMVU-03MTM-CS, Point Grey Research, Canada) with 16-mm fixed focal lens [17HD (2/3” 16 mm F/1,4 C-Mount, Tamron, Japan)] and 785-nm long-pass edge filter (BLP01-785R, Semrock) was used for fluorescence detection. A 20 lumen, resolution pico projector kit (DLP Lightcrafter™, Texas Instruments, Dallas, Texas) was used to project images.