Proffered Presentations Archive

UK & Ireland Prostate Brachytherapy Conference 2024

Abstract number 21 

Using ProKnow to set up an inter Trust database of post implant dosimetry for prostate iodine-125 implants.

Daniel Emmens
Maidstone and Tunbridge Wells NHS Trust 

Purpose: An inter-Trust collection of post implant LDR brachytherapy prostate patients has been set up in ProKnow to: (i) Assess how dosimetry across multiple centres compares against RCR minimum guidelines [1]. (ii) Acquire insights into how different techniques could affect dosimetry. (iii) Evaluate ProKnow for reporting post implant dosimetry. 

Methods: Participating Trusts within NHS England exported post-implant DICOM data from their treatment planning system (TPS) to an organisation collection in ProKnow where the data is effectively anonymised. Patients were implanted in 2023 and prescribed 145 Gy. A dosimetric scorecard was attached to the collection based on RCR minimum guidelines, including D90% prostate > 130.5 Gy and D2cc rectum < 145 Gy [1]. Additional implant information was acquired using custom metrics and a questionnaire. ProKnow uses the dose cube to recalculate dose-volume parameters. Centres compared calculated parameters in ProKnow and their TPS for a minimum of 10 patients. 

Results: There are 340 patients in the ProKnow collection from eight Trusts. Data collection is ongoing. 95% received D90% prostate > 130.5 Gy and 91% received D2cc rectum < 145 Gy. Mean values were 164 ± 18 Gy for D90% prostate and 108 ± 29 Gy for D2cc rectum. Between Trusts the mean D90% prostate varied from 153 Gy to 177 Gy and the mean D2cc rectum varied from 88 Gy to 130 Gy. Mean differences between ProKnow and TPS calculations of D90% prostate ranged from -2.8% to 4.5% depending on Trust and TPS system. 

Conclusion: The tools in Proknow enable individual Trusts to compare their LDR prostate post implant results and discuss/investigate results locally. At least 90% patients met the RCR minimum requirements. The data collected would be useful to new centres starting LDR. 

References: 

1. The Royal College of Radiologists. Quality assurance practice guidelines for transperineal LDR permanent seed brachytherapy of prostate cancer. London: The Royal College of Radiologists, 2012