A system for at least partially filling and marking a cavity within a patient includes a delivery device. A quantity of marker forming fluid is located within the delivery device. The quantity of marker forming fluid is configured to at least partially fill the cavity and form therein a bioabsorbable body after delivery into the cavity from the delivery device. A radiopaque marker, separate from the quantity of marker forming fluid and releasably attached to a portion of the delivery device, is configured to be delivered into the quantity of marker forming fluid in the cavity from the delivery device and configured to remain in the bioabsorbable body upon the formation of the bioabsorbable body in the cavity.