In medical jargon, this is called a “laterality error”. In reality, these very rare events are very difficult to live with for those who are its victims. By trusting their doctor, their oncologist, their radiotherapist and all the practitioners around them, these sick people do not imagine for a second that they could be victims of such an obvious error, when the caregiver wrong side on the body. And yet. In recent years, “laterality errors” have been on the increase, warns the Nuclear Safety Authority.
The first victims are often women suffering from breast cancer, and who undergo multiple radiotherapy sessions… on the wrong breast. How are such errors possible? And why is ASN warning of their resurgence? According to specialists contacted by 20 Minutesthe reasons could be found in medical progress. This seems strange to you. Not so much.
Our file on breast cancer
At the beginning of 2024, a woman received 20 sessions of radiotherapy in the wrong breast at the Burgundy Cancer Institute, in Dijon. A few weeks later, a patient suffered the same trauma at the greater Montpellier cancer center. At the end of 2023, it was at the CHRU Bretonneau in Tours that a similar error was made, causing 25 sessions in the wrong zone. According to the profession, the health risk would be minimal for patients, who nevertheless remain very affected by these errors of human origin.
These three significant events in a few months alerted the Nuclear Safety Authority. “The volume is very low. We are talking about less than 10 events in 2023 and 2024. But it is the deterioration that worries us more than the number itself. Four or five years ago, we no longer had these events,” assures Emilie Jambu. Asked about the reasons for this progression, the head of the Nantes division at ASN admits that she does not have all the answers. “We know that there are sometimes staff shortages which lead to the cancellation of prior visits. But it’s just one idea.”
“Before, it was impossible to make a mistake”
If the recruitment of radiotherapy technicians is not simple, it would not be the origin of these errors, according to Dr Erik Monpetit. “In 2023, we carried out 216,000 radiotherapy patient treatments in France. And we have three events which have been the subject of reports. It’s very little. But I recognize that it is three too many,” explains the president of the National Union of Radiological Oncologists. For him, these errors are more due to the spectacular progress in the treatment of breast cancer. “Before, most women either had their breast removed or had a very visible scar. It was impossible to go wrong. But for three or four years, it has been increasingly difficult to see which breast has been operated on,” explains the practitioner based in Vannes (Morbihan).
The “tattoo point” which marked the breasts of treated women for life has also disappeared due to technological progress.
The rapid development of radiotherapy machines has also overtaken patients’ comments. Previously, women could alert the manipulator when they saw the device approach the wrong area or were made to raise the wrong arm. “Today, the patient no longer sees which breast we are going to treat because the machine is spinning around her,” continues Dr. Monpetit. Reducing the number of sessions also helped reduce redness linked to burns generated by the treatment. Progress that benefits the patient but forces practitioners to be even more vigilant. “All it takes is one error on a mammogram or a poorly written report. Before, these errors were detected. But today, we hardly see anything anymore,” assumes Professor Véronique Vendrely.
A small thread along the scar
Elected in January at the head of the French Society for Oncological Radiotherapy (SFRO), Professor Vendrely alerted his entire profession, calling for the greatest vigilance regarding these laterality errors. It could be inspired by the work carried out at the Saint-Yves oncology center in Vannes, where a discreet thread is placed along the patients’ scar, in order to make it more visible during their treatment. To limit the risk of error, it is also advisable to carry out multiple checks by different people.
A working group bringing together professionals from the sector and the Nuclear Safety Authority will also be created to analyze each of the failures.
