A support apparatus (100, 2100) configured to support a patient's anatomy, the support apparatus (100, 2100) comprising: at least one support (10, 12, 2112, 2110) configured to support a patient's anatomy, the at least one support (10, 12, 2112, 2110) comprising: at least one top portion; and at least one base portion; at least one locator configured to removably locate the support apparatus (100, 2100) to a patient table of a target modality; at least one directional guide having a set distance of travel; at least one shuttle coupled to the at least one support (10, 12, 2112, 2110), the shuttle being configured to slidably adjust the support (10, 12, 2112, 2110) along the at least one directional guide; at least one releasable lock configured to restrict movement of the at least one shuttle along the at least one directional guide in a first engaged configuration, and enable movement of the at least one shuttle along the at least one directional guide in a second disengaged configuration; wherein a gross position of the support apparatus (100, 2100) is selected by locating the at least one locator to a corresponding structure on the patient table of the target modality and wherein a position of the support apparatus (100, 2100) may be finely adjusted in discrete increments along the set distance of travel of the at least one directional guide; and wherein the base portion is removably attached to the at least one top portion, and is additionally coupled to the at least one directional guide, the at least one locator, the at least one shuttle, and the at least one releasable lock, wherein the at least one base portion is configured to be oriented in at least a first orientation and a second orientation, and wherein the at least one base portion is configured such that it will be at a first height in the first orientation and at a second height in the second orientation. at least one top portion; and at least one base portion; at least one locator configured to removably locate the support apparatus (100, 2100) to a patient table of a target modality; at least one directional guide having a set distance of travel; at least one shuttle coupled to the at least one support (10, 12, 2112, 2110), the shuttle being configured to slidably adjust the support (10, 12, 2112, 2110) along the at least one directional guide; at least one releasable lock configured to restrict movement of the at least one shuttle along the at least one directional guide in a first engaged configuration, and enable movement of the at least one shuttle along the at least one directional guide in a second disengaged configuration; wherein a gross position of the support apparatus (100, 2100) is selected by locating the at least one locator to a corresponding structure on the patient table of the target modality and wherein a position of the support apparatus (100, 2100) may be finely adjusted in discrete increments along the set distance of travel of the at least one directional guide; and wherein the base portion is removably attached to the at least one top portion, and is additionally coupled to the at least one directional guide, the at least one locator, the at least one shuttle, and the at least one releasable lock, wherein the at least one base portion is configured to be oriented in at least a first orientation and a second orientation, and wherein the at least one base portion is configured such that it will be at a first height in the first orientation and at a second height in the second orientation.