A system and a method of performing a frameless image-guided biopsy uses imaging, a six-dimensional robotic couch system, a laser guidance system, an optical distance indicator, and a needle control apparatus. A planning CT scan is made of the patient with stereotactic fiduciary markers to localize and produce digitally reconstructed radiographs. Two stereoscopic images are generated using an imaging device to visualize and identify a target tumor. The images are fused with the digitally reconstructed radiographs of the planning CT scan to process tumor location. The tumor location data are communicated to the movable robotic couch to position the target tumor of the patient at a known isocenter location. A biopsy needle is guided with a laser alignment mechanism towards the isocenter at the determined depth using a needle positioning apparatus and an Optical Distance Indicator, and a biopsy sample of the target tumor is obtained.