New era of electronic brachytherapy

Area of Science:

• Medical Physics
• Oncology
• Radiotherapy

Background:

• Brachytherapy involves placing radioactive sources on or inside cancerous tissues.
• Electronic brachytherapy utilizes miniaturized X-ray sources, differing from traditional radionuclide methods.
• Key advantages include lower doses to organs at risk and reduced exposure for staff.

Discussion:

• Electronic brachytherapy systems typically operate between 50 and 100 kVp, ideal for skin cancer treatment.
• Systems like Intrabeam and Xoft are used for intra-operative radiotherapy, including breast treatments.
• The rapid dose fall-off of low-energy X-rays minimizes radiation to surrounding normal tissues.

Key Insights:

• The Xoft Axxent system, using a 2.25 mm X-ray tube, is unique for cervical cancer treatment.
• Its dose rate approximates that of the Ir-192 source.
• The primary limitation for interstitial brachytherapy is the source dimension.

Outlook:

• Advancements in miniaturized X-ray tube design are expected.
• Future designs may approach the dimensions of Ir-192 wires, enabling wider interstitial applications.
• A new era of electronic brachytherapy is anticipated with these technological developments.