Systems and methods for guiding tissue resection

A patient-specific device for guiding resection of a tumor located in a tissue of a patient, comprising:

• a locator form having a locator-form surface matching a surface of the tissue near the tumor's location when the tissue is imaged in a first position of the patient in which the surface of the tissue has a first shape, such that the locator form, when fit to the surface of the tissue when the patient is in a second position in which the surface of the tissue has a second shape, restores the tissue to the first shape;
• and
• a surgical guidance cue integrally formed with the locator form and based on images including only images of the tissue in the first position, to indicate a spatial property of the tumor in the first position;
• wherein the second position differs from the first position, and the second shape differs from the first shape.