Proffered Presentations Archive

UK & Ireland Prostate Brachytherapy Conference 2024

Abstract number 22 

Commissioning for HDR prostate Brachytherapy: Early Clinical Experience

Rissa Cunningham, Emma Jones, Regina Gonzalez Vaz, Ben Scarlet
Guy’s and St Thomas’ NHS Foundation Trust 

Purpose: To outline the comprehensive commissioning process for High Dose Rate (HDR) prostate brachytherapy and present our early clinical experience. At Guy’s and St Thomas’, we implemented a CT and MR based HDR prostate treatment technique by inserting catheters into the prostate using ultrasound guidance [1]. This method involves CT and MR scans, image fusion, planning and treatment delivery. A final verification CT is taken before the patient is treated to check for catheter displacement. 

Methods: An anthropomorphic phantom was used to ascertain the most efficient treatment planning pathway in Oncentra (V4.6), including optimal catheter reconstruction, inverse planning algorithm class solution [2] and fusion technique. Dosimetry verification measurements were performed in a mini water phantom fitted with an in-house manufactured jig that allowed mimicking an interstitial prostate HDR treatment delivery whilst measuring with two different detectors, namely a PTW pinpoint chamber and TLDs. 

Results: The commissioning process confirmed a good agreement between the calculated dose on the TPS against the measurements taken with the water tank. The results showed the favourable detector to verify the TPS dose were using TLDs, as a result of an energy dependence on the ionisation chamber. The anthropomorphic phantom was successfully utilised to design a complete pathway to deliver accurate and safe treatment in an optimal timeframe. Since the service has gone clinical, we have successfully treated 3 patients. 

Conclusion: Our HDR prostate BT commissioning followed a well streamlined process providing an efficient, effective and robust foundation for the implementation of this treatment modality in clinical practice. Our early clinical experience suggests that HDR prostate brachytherapy is an effective option for prostate cancer patients, with favourable treatment outcomes. 

References: 

1. PJ Hoskin et al. Radiother Oncol. GEC/ESTRO recommendations on high dose rate afterloading brachytherapy for localised prostate cancer: An update – 2013, 05, 01; 107:3 
2. S Giannouli and D Baltas. White Paper. Hybrid Inverse Planning Optimization for Brachytherapy Treatment Planning – 2014