Poster Abstracts Archive

UK & Ireland Prostate Brachytherapy Conference 2011

Abstract number 9

Moving with the times: Evolution of technique in prostate brachytherapy

Eliot Chadwick, Royal Surrey County Hospital
Robert W Laing, Royal Surrey County Hospital
Stephen EM Langley, Royal Surrey County Hospital

Aim/Introduction: LDR prostate brachytherapy has been performed in Guildford since 1999. Innovation, and the availability of new technology, has brought about improvements in technique and outcomes. This evolution of technique is described here.

Methods: In 1999, the modified Seattle technique was used. At implantation, loose seeds were placed in the central prostate, using pre-loaded needles. Peripherally, stranded seeds were used. CT was initially performed at Day 28, but more latterly at Days 1 or 0.
From 2005, a novel approach was developed in response to concern regarding potency and catheterisation rates. Loose seeds used centrally were implanted individually, extending around the margins of the apex, avoiding the rectum, urethra and penile bulb. Peripheral stranded seeds were used as previously.
By 2008 a one stage technique incorporating real-time planning was developed. Patients undergo TRUS volume estimation in the clinic. A nomogram for seed ordering has been developed based on this measurement. After the peripheral seeds have been implanted, a plan is created to determine the number and placement of the central loose seeds.

Results: The 4 year bRFS was 94.8% vs. 94.5% for the novel vs. previous techniques. There was an improvement in dosimetry (D90 155Gy vs. 147Gy, p<0.05; V100 92% vs. 90%, p<0.05). This was also associated with an improvement in potency from 61.7 to 83.3% at 2 years (p<0.05). Post-implant catheter use fell from 17% to 2.6%. In 1999, the duration of anaesthesia for implant was 30-45mins, whereas in 2010, the same time is taken for a one-stage procedure.

Conclusions: A brachytherapy technique has been developed that is convenient to both the patient and clinician. Improved toxicity has been achieved without detriment to efficacy.