“…The modern era of cryosurgery was inspired by Cooper's landmark paper in 1963 in which he described using a closed liquid nitrogen probe system to freeze liver tumors in lab animals [52]. In the early 1970s, there were more reports describing the use of cryosurgery to treat liver tumors in lab animals [53,54]. During this same period, Zhou et al began treating primary hepatomas with surface cryosurgical probes [55].…”