Medical Physics

Ian Paddick

Chief Physicist

Ian began his career as a Medical Physicist in 1989, working at the Hammersmith hospital, London. Since 1998 he has worked almost exclusively with the Gamma Knife using the B, 4C, Perfexion and Icon Gamma Knife models.

He is a regular speaker and moderator at Radiosurgery conferences, teaching on training courses and helping start up new Gamma Knife centres worldwide.

His publications in Radiosurgery have established him as an authority in Radiosurgery dose planning. In 2003, Ian became a freelance physicist, providing physics services to Gamma Knife centres, as well as the manufacturers of the Gamma Knife; Elekta Instruments. In 2009 he published “Radiosurgery Treatment Planning”, the first book covering practical techniques of dose planning.

He currently serves as President of the International Stereotactic Radiosurgery Society and Vice President of the British Stereotactic Radiosurgery Society.

Alexis Dimitriadis

Senior Radiosurgery Physicist
Alex graduated with a BSc (Hons) in Radiotherapy and Oncology in 2010 from the University of Hertfordshire, having completed three years of clinical placements at Imperial College NHS Trust hospitals. He then went on to study for an MSc in Human Anatomy at the University of Edinburgh where he developed a keen interest in neuroanatomy and chose it as the subject of his dissertation. He was awarded with an MSc in 2011 and subsequently in the same year he joined Poole Hospital NHS Trust as a radiographer. In 2012 he joined the Royal Surrey County Hospital NHS Trust where he worked as a radiographer. He then gravitated towards radiotherapy physics and took a post in the radiotherapy physics department of the same hospital, working predominantly in prostate seed brachytherapy and in performing in-vivo dosimetry for patients undergoing external beam radiotherapy. Parallel to that, he developed an interest in radiosurgery physics and started conducting research in 2012 as part of his PhD studies at the University of Surrey. As part of his PhD work, Alex developed a method for assessing the dosimetric and geometric accuracy of stereotactic radiosurgery. His method was used to conduct a national audit of all 32 radiosurgery centres in the UK, the results of which were utilised in an assessment performed by NHS England to commission SRS services. This work was also endorsed the Radiotherapy Trials and Quality Assurance group as the dosimetric study required for the CORE and SARON clinical trials. Alex has presented his research findings in several national and international conferences and has also produced a number of publications in peer-reviewed journals. Since the completion of his PhD studies in 2016, he joined Medical Physics Limited and provides Radiosurgery physics services to Queen Square Radiosurgery Centre, Thornbury Radiosurgery Centre, Cromwell GammaKnife Centre and London GammaKnife Centre at Barts. He continues conducting research in radiosurgery physics and is an active member of the national, European and international radiosurgery and oncology societies.

Phil Tapper

Senior Radiosurgery Physicist
After graduating in Physics & Astrophysics from Queen Elizabeth College, London Phil trained in Radiation Physics at the Medical College of St Bartholomew’s Hospital which led to the award of an MSc in 1985. He then worked for a number of years in the NHS before moving into the private sector, eventually becoming Head of the Medical Physics Department including the London Gammaknife Centre at the Harley Street Cancer Centre. Since 2008 he has been providing radiosurgical physics support as a consultant, to Gamma Knife Centres.

After working in Radiation Protection for about 2 years he transferred to Radiotherapy at The Middlesex Hospital in 1988. He worked there for 5 years before moving on to the Royal Marsden NHS Trust in Fulham where he spent a further 6 years in Radiotherapy. These NHS posts gave Phil a thorough grounding in all aspects of radiotherapy physics within large teaching hospital environments.

In 1999, Phil moved into the private sector as Deputy Chief Physicist at The Harley Street Cancer Centre, a facility of the HCA International group of hospitals. Within a year he had been promoted to Chief Physicist and carried on to head the Medical Physics Department for a further 8 years. During his time at HSCC he oversaw the expansion of prostate seed brachytherapy and radionuclide therapy as well as the development of the Radiotherapy Department into a nationally recognised site of clinical excellence. More pertinently, in 2006, HCA International took over the London Gamma Knife Centre, and Phil’s department provided the physics support to this new facility.