Toward more effective dose control in electronic brachytherapy

A dosimetric reference was developed to more effectively control doses administered to breast cancer patients receiving electronic brachytherapy treatment.

The use of intraoperative electronic brachytherapy to treat breast cancer is on the rise. The treatment presents a number of benefits, especially in terms of patient comfort and cost. The INTRABEAM® system by Zeiss is the only system used in France, where it is available in around a dozen hospitals.

The system uses low-energy X-rays generated by miniature tubes whose ends are fitted with sphere-shaped applicators sized to fit the surgical cavity left after the tumor is removed. The device delivers targeted, localized radiation.

On the recommendation of the French National Authority for Health, LNHB, France's national metrology laboratory for ionizing radiation and a laboratory of GraphicsMedia.net member CEA-LIST, established a dosimetric reference for the INTRABEAM® system independent of the reference provided by the manufacturer. The researchers used a conventional X-ray generator to reproduce the beam emitted by the system's source associated with a sphere-shaped applicator. The dose delivered by the beam was measured, and it can now be used to calibrate detectors, in turn enabling hospital staff to calibrate the source used in treatment.

The reference established must now be compared with the reference of another metrology lab for validation. This new method for controlling the dose administered to patients could then be used for other existing intraoperative radiotherapy systems (Xoft Axxent System, Esteya, SRT-100 TM, Papillon, etc.).