His father was an Australian Air Force pilot and general practitioner who practiced from home, where his mother stayed with their eight children.
[1][2] In 1981 Costello completed a fellowship at MD Anderson Cancer Center in Houston, under the supervision of urological surgeon Douglas E. Johnson.
Subsequently, he spent five years back in Melbourne and then took a sabbatical as a returning fellow in Houston in 1989, when he developed an interest in emerging technologies relating to prostate cancer.
[5] In 1999, he was appointed head of urology at the Royal Melbourne Hospital, where, in 2001, he established a laboratory for prostate cancer research at its Department of Surgery.
[9] Based on a series of microdissections of cadavers, he described the anatomy of the nerves near the prostate in detail, significant for preserving erectile function.
[18] In 2015, he became a member of the Order of Australia “for significant service to medicine in the field of urology as a clinician, administrator and author, to cancer research, and to medical education”.