Room: Exhibit Hall
Purpose: To evaluate the novel Uronav Therapy system from Philips that integrates real-time electromagnetic (EM) tracking for intra-op US-guided HDR prostate brachytherapy.
Methods: The system was commissioned based on AAPM TG53, TG56 and TG128 recommendations for brachytherapy systems. First the ultrasound (US) QA phantom (CIRS - model 045A) was used to evaluate the image quality. Distances, volumes, and dimensions of the structures inside the phantom were measured and compared to the actual values. EM calibration was evaluated using a specifically designed QA tool mounted on the US probe and immersed in a water tank. Implementation of TG43 dose calculation for the Ir-192 Flexisource was validated by the comparison of the along-away dose table to data from AAPM/ESTRO 2012 consensus (HEBD group). Finally, simple geometry dose calculations were compared to OncentraBrachy (OCB) V4.5.2 (Elekta).
Results: US image quality evaluation showed differences with actual dimensions (lengths, widths and distances) smaller than 0.5% and differences in volume sizes smaller than 5%. The calibration of the EM stylet was performed and residual errors below 1 mm were observed for EM tracking in transverse and sagittal directions. The Flexisource model was evaluated and along-away normalized dose rate results from Uronav Therapy were compared to AAPM/ESTRO consensus data; results were in perfect agreement. Finally, dose calculations for simple geometries were also compared to OCB and observed differences were smaller than 1.5% except for point located inside the source were the error was higher.
Conclusion: The Uronav Therapy investigational system was commissioned and evaluated for clinical trial use. US images are accurate and no distortion was observed. The EM feature of the system was proven to be precise, opening the way for automated catheter reconstruction. TG43 implementation is in agreement with the ESTRO/AAPM HEBD consensus and finally, dose calculations were similar to OCB results.
Funding Support, Disclosures, and Conflict of Interest: This work is supported by Philips Healthcare