With the technological cryoprobe advancements in the 1960s, came wider acceptance and practice of cryotherapy. Since the 1960s, liver, prostate, breast, bone, and other cancers were being treated with cryoablation in many parts of the world. Japanese physician Dr. Tanaka began treating metastatic breast cancer cryoablation in 1968. For the next three decades, Dr. Tanaka successfully treated small and localized as well as advanced and unresectable breast cancer with minimally invasive cryoablation. All of Dr. Tanaka's breast cancer cases were considered incurable: advanced, unresectable, and resistant to radiotherapy, chemotherapy, and endocrine therapy. At the same time, physicians, including Dr. Ablin and Dr. Gage, started utilizing cryoablation for the treatment of prostate and bone cancer. Dr. Paul J. Wang MD and Dr. Peter L. Friedman MD, PhD invented cryoablation for the heart and cardiac arrhythmia in 1988. Their patents were for the cryoablation catheter and cryogenic mapping (US Patents 5147355A and 5423807A).