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EF 1 - Radiation incidents and accidents in medical imaging and their management (part I)

Friday, March 3, 08:30 - 10:00 Room: G Session Type: EFOMP Workshop: Radiation incidents and accidents in medical imaging: can we prevent them? Topics: Nuclear Medicine, Radiographers, EuroSafe Imaging, Physics in Medical Imaging Digital Evaluation: Open Digital Evaluation for this Session Moderators: J. Damilakis (Iraklion/GR), A. Torresin (Milan/IT) Add session to my schedule In your schedule (remove)

A-414

Chairman's introduction

J. Damilakis; Iraklion/GR

Learning Objectives

1. To learn about the common reasons for radiation incidents and accidents in CT and interventional suites.
2. To learn about the common reasons for accidental exposure during pregnancy.
3. To be informed about the EU BSS requirements on radiation incidents and accidents in medical imaging and their management.

Abstract

There are radiation incidents involving the exposure of a patient to a dose much greater than intended. Main reasons for these very high doses are a) lack of knowledge in medical radiation protection, b) poor equipment knowledge and c) use of inappropriate protocols. Accidental irradiation of pregnant patients during the first post-conception weeks leads to unnecessary termination of pregnancies. To avoid these radiation accidents, proper pregnancy screening is needed. In fluoroscopically guided interventional procedures with very long screening time, there is a possibility of cell killing sufficient to result in radiation-induced injuries in certain tissues of patients. There are also other causes of accidental exposure, for example, failure of staff to properly check the identity of patients. This may lead to radiation exposure of a patient who undergoes an x-ray procedure intended for another patient. Accidental medical exposures are a source of continuing concern. All measures should be taken to minimise the probability of accidental or unintended exposures of individuals subject to medical exposure.

A-415

Radiation incidents and accidents in CT

M. Mahesh; Baltimore/US

Learning Objectives

1. To give an overview of radiation incidents and accidents in CT.
2. To discuss the lessons learnt from these incidents and accidents.
3. To learn how to manage incidents and accidents in CT.

Abstract

Radiation incidents in diagnostic radiology are rare and may not be as life threatening as in radiation oncology, yet it is equally important to devise plans of action to address radiation incidents in diagnostic radiology. This talk will discuss various measures medical physicists can do to address such situations with focus on CT studies. Radiation incidents/accidents can lead to deterministic effects such as hair loss or skin erythema, which are rare but possible in CT scans (CT perfusion studies) due to incorrect settings or improper scanning. When radiation incidents occur, a physicist can do the following. First, physicist should record details of scan settings that have led to the radiation incident. Next, assess and make necessary changes to avoid future incidents. This should be followed by detail assessment of radiation exposure to patients (skin dose and organ dose) and work with the radiologists and other physicians to address the radiation events. Further, medical physicists can take precautions to avoid such incidents in future. Recently introduced ‘CT dose alert’ can be customized for each CT protocol such that incorrect settings that could lead to unintended high radiation exposure can be flagged prior to CT scan. In addition, features such as CT dose notification can further assist in periodic CT dose audits. This presentation will discuss in detail about the CT dose alert and CT dose notifications, which are key to avoid unintended radiation exposure to patients undergoing CT studies.

A-416

Radiation incidents and accidents in interventional suites

R. W. R. Loose; Nürnberg/DE

Learning Objectives

1. To give an overview of radiation incidents and accidents in interventional radiology.
2. To discuss the lessons learnt from these incidents and accidents.
3. To learn how to manage incidents and accidents in interventional radiology.

Abstract

The majority of radiation incidents and accidents in interventional suites are related to patients. Radiation accidents of staff members are very rare but may occur under specific circumstances. For example, staff members are at risk if parts of their body are for too long in the primary beam or if safety measures for new practices like SIRT with 90-Y are inadequate. A radiation accident to a patient means normally a deterministic injury - in most cases of the skin. Depending on the individual patient condition the threshold dose for accidents with skin injuries is above 2-5 Gy. Incidents may be unintended overexposures in the dose range of stochastic effects without injuries or “near miss” events without patient exposure. Incidents and accidents during interventional procedures can be avoided by precise and comprehensive standard operating procedures (SOP) and extensive training of all staff members involved. Every incident or accident should trigger a workup of the team to minimize the risk of a second occurrence. After a patient injury the patient and/or his relatives and the referring physician should be informed about recommendations for follow-up of possible lesions. The time delay in the occurrence of lesions may be in the range between 2 weeks and one year. Until February 6th 2018, the Council Directive 2013/59/Euratom has to be transposed into national regulations of member states requiring a recording and reporting of accidental and unintended exposures. Up to now, the approach of this transposition is unclear for many member states.

A-417

Accidental exposure during pregnancy

J. Damilakis; Iraklion/GR

Learning Objectives

1. To provide information about the frequency of accidental exposure of pregnant patients in imaging departments.
2. To learn how cases of accidental exposure of pregnant patients in imaging departments can be reduced.
3. To learn how to manage pregnant patients in case of accidental exposure to x-rays.

Abstract

Accidental irradiation of pregnant patients occurs during the first weeks of gestation. During the first 2 weeks postconception, radiation will terminate pregnancy or the embryo will either recover completely (all or nothing effect). From the 3rd to 8th week postconception, the most possible form of damage is organ malformations. However, these effects are not likely to be observed after diagnostic imaging. After accidental exposure of pregnant patients, conceptus dose estimation is needed. CODE (COnceptus Dose Estimation) is a free web-based software tool for the estimation of embryo dose from radiography, diagnostic fluoroscopy, CT and fluoroscopically guided procedures. For more information about CODE, please visit embryodose.med.uoc.gr. Careful screening is needed to avoid accidental irradiation during pregnancy. X-ray departments must have posters in the waiting area asking female patients to inform the radiographer or radiologist about a possible pregnancy. According to ICRP publication 84, ‘investigation of the reproductive status of a female of childbearing age prior to x-ray imaging’ is needed. Article 62 of the new EU BSS states that ‘Member States shall ensure that the referrer or the practitioner, as appropriate, inquire, as specified by Member States, whether the individual subject to medical exposure is pregnant or breastfeeding, unless it can be ruled out for obvious reasons or is not relevant to the radiological procedure’.