Reconstruction errors in clinical intraoperative TRUS-based prostate HDR-BT detected using electromagnetic tracking.

Area of Science:

• Oncology
• Medical Physics
• Radiotherapy

Background:

• Prostate cancer high-dose-rate brachytherapy (HDR-BT) relies on accurate implant reconstruction.
• Transrectal ultrasound (TRUS)-based methods can introduce reconstruction errors.

Purpose of the Study:

• To investigate errors in TRUS-based implant reconstructions for prostate HDR-BT.
• To evaluate the utility of an afterloader-integrated electromagnetic tracking (EMT) system in identifying these errors.

Main Methods:

• Fourteen patients undergoing prostate HDR-BT had intraoperative EMT measurements.
• Euclidean distances between clinically reconstructed and EMT-measured dwell positions were calculated.
• Errors were stratified into severity levels and causes investigated.

Main Results:

• Median Euclidean distance between measured and reconstructed positions was 1.0 mm.
• 23% of reconstructions had minor or higher errors; 9% had major or severe errors.
• Error causes included incorrect needle/depth selection, artifacts, shadowing, and user errors.

Conclusions:

• A significant proportion of HDR-BT implant reconstructions contain errors.
• EMT can detect reconstruction errors without disrupting the clinical workflow.
• EMT offers a valuable tool for improving the accuracy of prostate HDR-BT.