IOMP Webinar: Radiation Doses and Risk in Imaging – to Know or Neglect?

Radiation Doses and Risk in Imaging – to Know or Neglect?
Tuesday, 20th June 2023 at 12 pm GMT; Duration 1 hour

Organizer: Prof Magdalena Stoeva
Moderator: Prof Arun Chougule
Speakers: Prof Dr Anchali Krisanachinda and Prof Dr Tomas Kron

Title: Imaging doses in radiotherapy: to know or neglect?
Speaker: Prof Dr Tomas Kron
Tomas Kron was born and educated in Germany. After his PhD he migrated to Australia in 1989 where he commenced his career in radiotherapy physics. From 2001 to 2005 he moved to Canada where he worked at the London Regional Cancer Centre on the commissioning of one of the first tomotherapy units. In 2005, Tomas became principal research physicist at Peter MacCallum Cancer Centre in Melbourne, Australia where he now is Director of Physical Sciences. He holds academic appointments at Wollongong, RMIT and Melbourne Universities. Tomas has an interest in education of medical physicists, dosimetry of ionising radiation, image guidance and clinical trials demonstrated by 100 invited conference presentations and 330 papers in refereed journals. He has received many awards over the years including an Order of Australia Medal (2014), Fellowship of IOMP and IUPESM and Life Membership of the TransTasman Radiation Oncology Group (TROG) in 2020.

Abstract:
Radiotherapy is one of the main treatment modalities for cancer patient. It uses target doses in excess of 50 Gy to eradicate tumour cells. In the context of this high dose many people consider dose from imaging procedures that allow for treatment planning and delivery verification to be negligible, a position reflected in the lack of education about imaging dose optimisation for radiotherapy physicists and scant dose reduction methods available on commercial radiotherapy equipment. This presentation argues that this is a mistake not only because the framework of radiation protection urges us to justify and optimise all radiation doses. The number and complexity of imaging procedures is increasing and the volume of the patient irradiated and dose distribution in imaging is fundamentally different form the high dose region in therapy. As such a recently formed task group of ICRP is dealing with imaging dose in radiotherapy. This and experience of managing imaging dose in a large radiotherapy centre will be subject of the presentation.


Title: Radiation-induced Cancer Risk in Medical Imaging: To know or Neglect?
Speaker: Prof Dr Anchali Krisanachinda
Anchali Krisanachinda graduated her B.Sc.(Hons) in Physics, M.Sc. (Radiation Physics) from University of London, UK, and Ph.D. (Medical Radiation Physics) from University of Health Science, North Chicago, Ill, USA. She was a Director of Medical Physics Graduate Program, Mahidol University, Bangkok, Thailand. She established Medical Imaging/Medical Physics, graduate programs, M.Sc. and Ph.D. at Chulalongkorn University and became Chairperson of both programs. She established Thai Medical Physicist Society (TMPS) in 2002, started the clinical training of medical physicists in 2007 and obtained Clinically Qualified Medical Physicist, CQMP, in radiation oncology, ROMP in 2009, DRMP in 2012 and NMMP in 2015. Then all 3 branches in medical physics clinical training were started at the same time using AMPLE (Advanced Medical Physics Learning Environment). Medical Physicists in South-East Asia join AMPLE sharing Thai Clinical Supervisors in ROMP and NMMP. The Ministry of Public Health of Thailand approved the medical physics national license in 2022, more than ten years after she requested. Hopefully, in 2023, there will be 300 Thai medical physicist with national license in medical physics. Continue Professional Development in medical physics will be later established. She has received many awards from her Faculty of Medicine and Chulalongkorn University, South-East Asian Federation of Organizations for Medical Physics (SEAFOMP), Asia-Oceania Federation of Organizations of Medical Physics (AFOMP), IOMP and IUPESM.

Abstract:
The risk model, the cancer sites, dose and dose rate effectiveness factor (DDREF) and mathematical models will be described presenting differences among the models. These models take into account parameters such as sex, age-at-exposure, attained age and time since exposure.
Patient dose from a chest X-rays is about 0.1 mSv, whole-body CT scan is about 10 mSv. The effective doses from diagnostic CT procedures may be associated with an increase in the possibility of fatal cancer of approximately 1 chance in 2000. This increase in the possibility of a fatal cancer from radiation can be compared to the natural incidence of fatal cancer in the U.S. population, about 1 chance in 5 (400 chances in 2000). In other words, for any one person the risk of radiation-induced cancer is much smaller than the natural risk of cancer. If the natural risk of a fatal cancer is combined to the estimated risk from a 10 mSv CT scan, the total risk may increase from 400 chances in 2000 to 401 chances in 2000.