SU-E-T-236: Brachytherapy for Breast Cancer Patients with Implanted Pacemeker, Using Multi Lumen Partial Breast...

Area of Science:

• Oncology
• Medical Physics
• Radiotherapy

Background:

• Implanted pacemakers pose a challenge for breast cancer radiotherapy, particularly Accelerated Partial Breast Irradiation (APBI).
• High-dose-rate brachytherapy requires careful planning to avoid overdosing sensitive implanted devices.

Purpose of the Study:

• To discuss the optimized use of a Strut-Adjusted Volume Implant (SAVI) applicator for APBI in patients with pacemakers.
• To ensure effective tumor coverage without exceeding the dose limit for the pacemaker and its leads.

Main Methods:

• A patient with a right-sided pacemaker underwent breast-conserving surgery and High Dose Rate (HDR) brachytherapy using an Ir-192 source.
• A seven-catheter SAVI device was implanted, and a 3D treatment plan was generated using the Oncentra Brachy system.
• Optimization tools, including Inverse Planning Simulated Annealing (IPSA), were used to minimize the dose to the pacemaker.

Main Results:

• The SAVI device allowed for the delivery of APBI while keeping the pacemaker/lead dose below the 2Gy threshold.
• Achieved target coverage: V100=90.1%, V95=95.5%, V90=98.5%.
• The average dose to the pacemaker assembly over ten fractions was 140cGy, with no observed change in pacemaker function.

Conclusions:

• Optimized HDR brachytherapy with a SAVI applicator is a safe and effective treatment option for breast cancer patients with implanted pacemakers.
• Advanced planning and optimization tools enable the delivery of radiation without compromising pacemaker functionality.