VersantCast Podcast

VersantCast Podcast

Featured Episode: Global Oncology with Dr. John Schreiner

Episode 5 | Recorded february 19, 2021


Global Oncology

With Dr. John schreiner, phd, fccpm, fcomp, faapm




With Dr. Alan Fellman, Ph.D., CHP

Radiation in Space



With Dr. Darrell fisher, Nuclear Medicine Physicist

Our Goals and Vision

Radiation in Space. An in-depth look at MIRD. What is radiation safety and why is it important? Versant Physics’ host Dr. Eric Ramsay converses with leading experts in the healthcare, medical and health physics, and radiation safety fields. We dive into the important topics that make up our industry’s current culture and showcase the impact the field has on the world. We hope that these conversations will inform, inspire, and educate our listeners.

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Dr. L. John Schreiner



Dr. L. John Schreiner has been a radiation therapy physicist since 1986 when he joined the Medical Physics Unit directed by Dr. Ervin Podgorsak at McGill University in Montreal. In 1997, after 10 years at McGill and the Montreal General Hospital, and about 2 years at the Vancouver Island Cancer Centre, he became the Chief Medical Physicist at the Cancer Centre of Southeastern Ontario in Kingston, Ontario. He is cross appointed as Adjunct Full Professor in the Departments of Oncology and Physics, Engineering Physics and Astronomy and has an appointment to the School of Computing at Queen’s University. He has been board certified by the Canadian College of Physicists in Medicine (CCPM) as both a member (MCCPM) and fellow (FCCPM).

John’s research at the University of Waterloo (Ph.D., 1985) was in nuclear magnetic resonance studies of various tissue model systems under the mentorship of Prof. Mic Pintar. Over his career he combined his biophysics work in magnetic resonance relaxation measurements with his career in radiation therapy through the development of three-dimensional (3D) gel dosimetry. In 1999 he was an original organizer for what developed into 10 biannual International Conferences on Gel Dosimetry (IC3Ddose). He edited two of the ICD3Ddose conference proceedings and has been on the Scientific Organizing Committee for all 10 conferences. These meetings have been sanctioned by Canadian Organization of Medical Physicists (COMP), the American Association of Physicists in Medicine (AAPM) and the Commission on the Accreditation of Medical Physics Education Programs (CAMPEP).

From 1991 to 1993 John was the editor for the joint COMP and Canadian College of Physicists in Medicine (CCPM) Newsletter. He served on the CCPM Board from 1997 to 2004, three years of which he was CCPM President. He continues to serve regularly on CCPM examination committees and, since 2013, has been a member of COMP’s Quality Assurance and Radiation Safety Advisory Committee. In 2009 he was asked to lecture on gel dosimetry at the AAPM Summer School on Clinical Dosimetry Measurements in Radiotherapy, and in 2010 he was invited by the International Atomic Energy Agency to lecture for one week on regulatory issues for radiation safety in hospitals (Vilnius, Lithuania). He has served on the editorial committees for Medical Physics (for which he is a senior associate editor) and the Journal of Medical Physics (India). In 2013 he was invested as FCOMP, a Fellow of COMP for contributions to Canadian medical physics. In 2017 he was awarded the distinction of FAAPM, Fellowship in the American Association of Physicists in Medicine for contributions to the field. That year he was also made a University of Waterloo, Faculty of Science Alumni of Honour for University’s 60th Anniversary, in recognition of outstanding vision, professional dedication and commitment to excellence. He is currently leading an effort to establish a virtual medical physics mentoring program linking experienced medical physics mentors with mentees in low-and-medical income countries.

In his research, he and collaborators at Queen’s University has proposed new radiochromic materials for 3D dosimetry, developed less toxic dosimeters for improved polymer gel dosimeters for clinical applications, advanced open source analysis software tools for film and gel dosimetry, and developed clinical protocols for their use using optical detection methods. He is the originator of the cobalt-60 advanced radiation delivery research program in Kingston, having initiated both the dose delivery and the Co-60 computed tomography (CT) imaging research. This work is unique to Kingston.

John is particularly proud of two aspects of his career: 1) he introduced scientists across North America to the field of 3D gel dosimetry, a field in which Canada is a major player; and 2) he has supervised over 120 trainees from the undergraduate to post-doctoral/clinical resident levels, introducing them to radiation therapy medical physics. The majority of these trainees have gone on to very successful careers in the field; 5 former graduate students are Chief Physicists in various centres across the USA and Canada. They also enabled John to publish research in a number of areas (reported in ~110 peer reviewed publications). His work is currently or was recently funded through grants from the Canadian Institutes of Health Research (CIHR), Natural Sciences and Engineering Research Council (NSERC) and the Ontario Research Fund Excellence Program (through OCAIRO, the Ontario Consortium of Adaptive Interventions in Radiation Oncology.)

John is an avid paddler who enjoys being on the water and camping with his three lovely daughters and very patient wife.


113 scientific articles published or in press in refereed journals, 8 book chapters/refereed conference proceedings

11 manuscripts in preparation/submitted to refereed journals, 44 publications in conference proceedings

148 published abstracts, 107 invited presentations


1976: B.Sc. Honours Physics | McGill University

1978: M.Sc. Physics/Biophysics | University of Waterloo

1985: Ph.D. Physics/Biophysics | University of Waterloo