Dr Callaghan qualified as a Radiation Oncologist in 1993. He served his period as a registrar at Addington Hospital in Durban and entered private practice in 1994. During this time he continued to work as a part-time consultant in the public sector. He also acted as Part time lecturer and examiner/moderator for the Department of Radiography, Technikon, Natal

He moved to establish an independent practice in 1995. In 2008 he, together with Dr Greg Landers, purchased the house at 535 Peter Mokaba Road and organised the refurbishment that has resulted in The Oncology Centre

Dr Callaghan has been active in the SASRO (South African Society of Radiation Oncologists) for many years. He participates in trial work and has presented several papers at congresses and meetings. He is recognised as an expert in cranial stereotactic radiotherapy (the treatment of small lesions within the brain).He also performs the highly specialised prostate Brachytherapy treatments in conjunction with a urologist and a physicist. Here a minute radioactive pellet is inserted directly into the prostate to treat small, localised lesions.

Chemotherapy is administered on site in Dr Callaghan’s rooms by a team of specialist oncology sisters. Dr Callaghan also conducts clinics and administers chemotherapy at Netcare Umhlanga Hospital in Umhlanga Rocks, Durban and Netcare Alberlito Hospital in Ballito on the KwaZulu-Natal North coast

Dr Callaghan has an associate oncologist in his practice – Dr Ingrid Craig. He will be joined by a second associate early in 2011. This ensures 24 hour service to patients of The Centre.