Exceeding of the maximum regulatory annual effective dose by a practitioner in interventional radiology – Montsouris Mutualistic Institute (Paris)

On 6th May 2013, the French nuclear regulatory body (ASN), was informed by the Head of the hospital “Institut Mutualiste Montsouris” that a radiologist performing radio-guided procedures^[1] had received an effective dose exceeding the maximum regulatory dose limit of 20 mSv (milliSievert) in twelve consecutive months.

ASN carried out an inspection on 17th May 2013 to examine the circumstances that led to this exceeding of the maximum effective dose.

The event was notified after the hospital's senior management received a report from the occupational physician on 29th April 2013 concerning repeated exceedances of the annual effective dose since July 2012 (effective dose of 22 mSv received between January and June 2012, rising to 35 mSv between January and September 2012, and finally totalling 48 mSv over the entire year 2012).

Further to these exceedances, the occupational physician issued a first medical opinion of unfitness for exposure to ionising radiation on 29th January 2013, which remained without effect and was issued for a second time on 22nd May 2013.

ASN reported this deficiency in the medical monitoring of the worker to the regional occupational medical inspector (MIRTMO in French) on 7th June 2013.

In the wake of this inspection, ASN asked the institute to suspend the radiologist from activity that would involve exposure to ionising radiation, in accordance with the opinion of unfitness issued by the occupational physician.

In addition to this, the inspectors observed that the radiologist, despite being excluded from activities involving exposure to ionising radiation since 29th January 2013, was still practising in regulated areas and was not wearing the active dosimeter provided by the employer. The radiologist also stated that he did not always wear the personal protective equipment at his disposal (protective apron and thyroid shield.

ASN underlines the importance of wearing personal protective equipment and considers that efforts must be made to optimise practices in order to reduce exposure to ionising radiation. ASN moreover observed that no complementary dosimetry measures were available, and asked the employer to review the workplace studies and to set up appropriate dosimetric monitoring where necessary.

Lastly, ASN underlines that all significant events have to be notified without delay.

Due to the exceeding of the annual regulatory limit of whole body exposure to ionising radiation for a worker, and the observed lack of radiation protection culture, ASN rated this event level 2 on the INES scale, which comprises 8 levels.

Press contact: Evangelia Petit, Head of the Press Department, tel: (+33) 1 46 16 41 42 evangelia.petit@asn.fr

[1] When performing medical procedures (intra-articular injections, for example), radiologists use X-ray emitting devices which enable the path of the needle to be viewed and help guide the practitioner's movements. Performing these procedures induces exposure to ionising radiation, particularly on the practitioner's hands. The levels of radiation - which can be substantial - vary according to individual practices, the radiological image acquisition parameters and the use of personal protective equipment.