ESTRO-Elekta Brachytherapy Award

ESTRO 2025 Congress Report | Brachytherapy track

Patient identification errors in radiotherapy, though rare, can have serious consequences, especially in brachytherapy, in which high radiation doses are delivered over short distances with high accuracy. Despite the stakes, most brachytherapy departments rely on manual double-checks to catch errors such as patient- or treatment-plan mix-ups. Such mix-ups are easily preventable in theory — for example, by asking each patient to confirm their name and date of birth — but in practice, they still occur, typically due to workflow pressures, distractions, or lapses in routine procedures, and they will likely continue to occur. Our research set out to change that by developing an automated identification system that used the unique geometry of breast brachytherapy implants to verify each patient before treatment began.

The method is based on electromagnetic tracking (EMT), which is a technology already used in brachytherapy for tasks such as reconstructing applicators or guiding interstitial needle placement. We adapted EMT to capture the precise configuration of the catheters that had been implanted in a patient’s breast, with sub-millimetre accuracy and without dose exposure. The EMT sensor is seamlessly integrated into the afterloader check cable run — the mandatory safety step that is performed before every treatment fraction — so our system fits neatly into existing clinical workflows without causing major delays.

We evaluated this approach retrospectively using data from 75 breast cancer patients who had received brachytherapy either as a boost after whole breast irradiation or as accelerated partial breast irradiation. In total, we simulated 5,625 comparisons between patient-specific implants and treatment plans. Our goal was to see whether the system could correctly match the right implant to the right plan, and could identify when a mismatch occurred.

The results were very promising. With a universal comparison threshold, the system achieved 99.7% accuracy in identifying the correct patient, and the sensitivity was 81.5% at 0% false positives. That means it never falsely identified a wrong patient or plan as correct — a crucial requirement for clinical adoption.

What makes this approach particularly compelling is its simplicity and reliability. Each implant acts as a physical ‘ID card’ that is temporary and therefore data-protection-friendly, as it cannot be traced back to the patient after the treatment is complete. EMT gives us a way to read that card automatically. Our study shows that implant-based identification is not only feasible but highly effective, and it adds another layer to the safety net in a critical area of radiotherapy.

We believe this solution could set a new standard for patient verification in brachytherapy and potentially be extended to other forms of implant-based treatments in the future.

Dr Christopher Dürrbeck
Medical physicist and post-doc researcher
Department of Radiation Oncology, Universitätsklinikum Erlangen
Erlangen, Germany

Reference

Implant-based patient identification using electromagnetic tracking: a novel, automated solution to prevent patient mix-ups in breast brachytherapy

C. Dürrbeck, R. Fietkau, V. Strnad, C. Bert