A method, system, and program product are provided for user-steered, on-the fly path planning in an image-guided endoscopic procedure, comprising: presenting, on a display, a 2D sectional image showing a region of interest from a preoperative CT scan； defining a control point on the 2D sectional image within a patient's body lumen responsive to a first user input； centering the control point； adjusting a viewing angle about the control point to show a longitudinal section of the body lumen responsive to a second user input； identifying a second point on a planned path within the body lumen responsive to a third user input； extending a planned path connecting the control point and the second point； redefining the second point as a new control point； and repeating the presenting adjusting, identifying, extending, and the redefining steps until the planned path reaches a procedure starting point within the patient's body.
