Anchored Transponder Guided Lung Radiation Therapy

Area of Science:

• Medical Devices
• Pulmonology
• Radiation Oncology

Background:

• Lung cancer treatment requires precise tumor targeting for effective radiation therapy.
• Traditional localization methods can face challenges with respiratory motion.
• The Calypso Beacon transponder was modified with a nitinol anchor for improved positional stability during bronchoscopic implantation.

Purpose of the Study:

• To evaluate the feasibility and safety of implanting anchored transponders in the lung via bronchoscopy.
• To assess the accuracy and reliability of lung target localization and tracking using the Calypso system with anchored transponders.
• To confirm the positional stability of the nitinol-anchored transponders during radiation therapy.

Main Methods:

• Patients with lung cancer (primary or metastatic) undergoing external beam radiation therapy were enrolled.
• Three anchored transponders were implanted into small airways (2-2.5 mm) using flexible bronchoscopy.
• The Calypso system was used for patient alignment and anchored transponder position tracking during radiation delivery.

Main Results:

• Anchored transponder placement was performed in 69 patients, with all 207 implants visible on CT scans.
• Localization was successful in 98.5% of patients (66 out of 67) during the first week of treatment, meeting the primary endpoint.
• Five potentially device-related adverse events occurred (pneumonia, pleural abscess, pneumothorax); anesthesia-related events were also noted.

Conclusions:

• Anchored transponders are a safe and effective tool for lung tumor localization and monitoring.
• The nitinol anchor feature provides positional stability, enhancing the reliability of tracking during radiation therapy.
• This technology demonstrates significant potential for improving the precision of lung cancer radiotherapy.