A medical guidance apparatus (100) includes a base assembly (110) configured to be attached to a subject and a guide (150) configured to be removably mated with the base assembly (110). The base assembly (110) has an opening (160), and the guide (150) includes a rotatable ring (152) and an arc member (154). The arc member (154) includes a first end (162) and a second end (164), the first end of the arc member is connected to the rotatable ring (152) and the second end extends diametrically opposite to the first end across the rotatable ring. A probe holder (600) is mounted on the arc member (154) so as to hold a needle-like instrument (2161) at a desired angle relative to an axis (Ax) of the rotatable ring (152). In some embodiments, the arc member is monolithically integrated with the rotatable ring. In other embodiments, the arc member is pivotable and/or completely removable from the rotating ring.