Prostate Brachytherapy UK & Ireland 11-12 June 2026

Oral & Poster Presentation – Abstracts Archive

UK & Ireland Prostate Brachytherapy Conference 2013

Abstract number 2

Comparison of Day-0 Ultrasound Real-time Dosimetry with Day 0 and Day 30 CT-based Dosimetry for Permanent Prostate Implants Using 125I Single Seeds-Initial Study

Louise Fahy
University Hospital Galway
Anysja Zuchora
University Hospital Galway
Jamsari Khalid
University Hospital Galway
Frank Sullivan
University Hospital Galway

Aims/Introduction: Day 30 CT-based dosimetry is the gold standard for final verification of prostate permanent implantation quality.  This initial study will investigate whether clinically significant changes in the dose to the prostate and critical adjacent structures occur between Day 0(CT-0) and 30 (CT-30). This is achieved using CT-based Dosimetry. Differences between Day-0 Ultrasound (US-I) and CT-0 are also analysed.

Materials/Methods: Dosimetry for 29 patients with permanent prostate implants using 125I seeds were evaluated using intraoperative US Day 0, CT imaging Day 0 and Day 30.

The dose received by 90% of the target volume (prostate D90), percentage of volume receiving 100%, 150% and 200% of prescribed dose (prostate V100, V150, V200), urethra D30 and D10, and rectal V2cc dose and prostate volume were analysed using Paired Student T-test. Differences were regarded as statistically significant at p < 0.05.

Results: This initial study shows significant differences between the CT-0 and CT-30 dosimetric parameters analysed. D90, V150 and V200 prostate and V2cc rectum mean values were higher for CT-30 than CT-0 and US-I.  US-I and CT-0 urethral and rectal dosimetric parameters showed no significant differences.  

Conclusions: Early verification of dosimetric parameters using CT-0 is desirable as sub-standard implants can be identified.  It is more convenient for the patient and allows verification of urethra dosimetry.

Based on this initial study, with limited patient numbers, CT-0 cannot replace CT-30 as the gold standard for final verification of prostate permanent implantation quality.