The following Abstracts were presented at the 2011 conference.

1. LDR Brachytherapy should be considered in Young Men with Prostate Cancer.
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2. Single fraction HDR boost. Report of toxicity from a single centre experience.
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3. Justification of pre-treatment correction of catheter movement in single fraction high dose-rate treatment of prostate cancer.
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4. Prostate Seed Brachytherapy - Can Ultrasound be used in Post Implant Dosimetry Analysis?
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5. UK Experience of Real Time Prostate Brachytherapy: A Report from Two Centres.
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6. Assessing the benefit of utilising higher activity seeds in larger prostate volumes.
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7. Overview of 11 Years Experience in I-125 Prostate Brachytherapy.
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The following abstracts were submitted and selected for poster presentation.

1. Sexually Transmitted Seeds?
   Read abstract >>
   
   
2. Moving with the times: Evolution of technique in prostate brachytherapy.
   Read abstract >>
   
   
3. A single institution’s experience of cytoreductive regimens prior to prostate brachytherapy.
   Read abstract >>

1. LDR Brachytherapy should be considered in Young Men with Prostate Cancer

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

Introduction
Brachytherapy achieves similar rates of biochemical control to radical prostatectomy in young men with prostate cancer. However, radical prostatectomy continues to be favoured in spite of known toxicity. The outcomes and toxicity for the only prospective UK series of young men treated by brachytherapy are presented.

Methods
Between 1999 and 2010, 118 out of 1700 patients treated by brachytherapy were <55 years old, Depending on MSKCC risk classification patients were treated with monotherapy (88), or with hormones (25) and/or EBRT (18). The implant technique has evolved with time from a 2-stage Seattle approach to a one-stage, real-time procedure. A bespoke, prospective database was used to collect clinical data.

Results
Overall survival was 100%. 76 patients had >3 years follow up, mean 76m. Of these 4 showed biochemical failure: 2 in low and 2 in high risk groups. Actuarial 8 year PSA free survival for the whole <55yrs group was 94% (cf. 84% for all ages). For the entire cohort, the median 5 year IPSS and QoL were 4 and 1.5 respectively.  Of the 75% patients potent pre-op, 81% retained potency (IIEF>11).  No secondary malignancies have been reported.

Conclusions
This is the first reported UK series of young men treated with LDR brachytherapy. The mature data demonstrates very effective tumour control and it is well tolerated.  When treatment is discussed with this patient group, LDR brachytherapy should be considered where appropriate.

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2. Single fraction HDR boost.  Report of toxicity from a single centre experience

JP Wylie, Christie Hospital, Manchester
P Mandall, Christie Hospital, Manchester
JP Logue, Christie Hospital, Manchester

Introduction

High dose rate (HDR) brachytherapy provides a convenient way of delivering high dose fractions of radiotherapy.  This is typically delivered as a boost in conjunction with a course of external beam radiotherapy and given in 2-3 fractions.  Multiple fractions erode the convenience of this modality to both the patient and treating team and may fail to fully exploit the low alpha beta ratio reported for prostate cancer.  We report our experience of delivering HDR brachytherapy as a single fraction of 12.5 -15 Gy prior to 37.5 Gy given via conventional conformal radiotherapy. 

Methods

Patient data was extracted from a prospective database sponsored by Nucletron.  Patient demographics are entered at the time of treatment and postal questionnaires detailing LENT SOMA, IPSS, EPIC QoL, catheter and alpha blocker usage were sent to the patient pre-treatment, 6 weeks after, then 6,12,18,24,36 and 48 months post treatment.  All patients received 3 months neo-adjuvant hormones followed by adjuvant hormones for 6-24 months dependant on perceived risk.

Results

Between July 2008 and February 2011 177 patients were treated.  Median age was 67 years (range 51-78), median Gleason score was 7 (range 6-10) and median initial PSA 16 (range 0.29-102).  Overall toxicity was modest.  IPSS peaked at 6 weeks and approached baseline at 6 months.  LENT SOMA bowel symptoms peaked at 6 months and approached baseline at 12 months.  There was no appreciable difference in reported toxicity between the initial cohort treated with 12.5 Gy and those receiving 15 Gy. 

Conclusions

Single fraction HDR boost appears a safe and convenient means of dose escalating.  A single fraction of 15 Gy is now our standard and has been adopted by several other U.K. brachytherapy centres.

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3. Justification of pre-treatment correction of catheter movement in single fraction high dose-rate treatment of prostate cancer.

David Inchley, Mount Vernon Cancer Centre
Gerry Lowe, Mount Vernon Cancer Centre
Clare Anderson, Mount Vernon Cancer Centre
Aled Parry, Mount Vernon Cancer Centre
David Polley, Mount Vernon Cancer Centre
Peter Hoskin, Mount Vernon Cancer Centre

Aim/Introduction:
Fractionated HDR prostate brachytherapy relies upon catheter positioning to achieve adequate tumour coverage whilst minimising dose to surrounding tissues. In multi-fraction treatments, peri-prostatic oedema may cause caudal displacement of the catheters relative to the prostate during the time between planning imaging and the subsequent fractions of treatment. A correction can be performed by moving the source positions within the needle (or physical advancement of the catheters).
We have extended this procedure to cover single fraction HDR prostate treatments.

Materials and Methods
To date 70 patients have been treated using a single fraction of HDR brachytherapy following EBRT to the prostate.
These patients were imaged for a planning scan as soon as possible after implantation. Before treatment, the CT imaging was repeated, and catheter movement correction applied. Treatment commenced as soon as possible after this CT.

Results
The mean time between planning and pre-treatment CT scans was 4 hours 12 minutes.
Movements were less than 3mm in 716 (51%) catheters. However, 213 (15%) catheters showed motion of greater than 5mm in the short time between planning and pre-treatment scans. Furthermore, in some cases (14%) catheter motion was in the opposite direction to that commonly seen after 24 hours, with 6% of these having moved more than 3mm.

Conclusion
There is already a literature justifying the need to perform catheter position correction between subsequent HDR fractions in multiple fraction treatments spanning a time greater than about 24 hours. Few groups, however, have looked at the first few hours after implantation.

This study has shown a different pattern of movements from that previously reported. There is clearly a need to perform correction for catheter displacement even if the treatment is delivered within a few hours of the planning scan, and this correction can be in either direction. Neglect of this has the potential to increase critical structure dose and decrease prostate coverage significantly.

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4. Prostate Seed Brachytherapy - Can Ultrasound be used in Post Implant Dosimetry Analysis?

Christopher Walker, St. Luke’s Radiation Oncology Network, Dublin.
Anysja Zuchora, University College Hospital, Galway
Frank Sullivan, University College Hospital, Galway
Margaret Moore. University College Hospital, Galway

Aims/Introduction:
AAPM recommendations (Nath et al. Med Phys. 2009 Nov;36(11):5310-22) state that post implant dosimetry of I-125 prostate seed brachytherapy be performed via CT guidance 30 ± 7 days after the procedure. This study attempts to determine whether TRUS based post-implant dosimetry parameters, determined on the day of the case, can be considered statistically equivalent to those acquired from a CT scan taken after 30 days.

Materials/Methods:
A retrospective study was performed, visually marking seeds on post-implant TRUS images for 43 patients using Varians Variseed™ software. Dosimetric parameters of D90, V100, and V150 for the prostate were determined for both TRUS and CT. A Paired Students T-Test and a Wilcoxon Paired Sample test were used to determine whether parameters based on these modalities could be considered statistically equivalent. Reproducibility tests were also carried out on the precision of the Variseed seed-finding software.

Results
Analysis showed that TRUS and CT D90 and V100 values could be considered statistically equivalent based on a significance level of 0.05, but V150 could not. For one patient, 100 iterations of the seed finder software on a post-implant CT image set yielded an average prostate D90 of (169.9 ± 2.2)Gy and V100 of (93.5 ± 0.7)%.

Conclusion:
The dosimetry parameters of D90 and V100 taken from a post-implant TRUS can be considered statistically equivalent to day-30 CT, however the V150 value cannot. This method has merit especially when natural gland motion occurs during the implant process or if artificial hips are present. The use of multiple iterations of the seed-finder on CT images is also suggested.

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5. UK Experience of Real Time Prostate Brachytherapy: A Report from Two Centres

Eleanor James, Berkshire Cancer Centre, Reading
Chris Elwell, Northampton Cancer Centre
Stuart Duggleby, Northampton Cancer Centre
Philip Camilleri, Northampton Cancer Centre
Andrew Doggart, Berkshire Cancer Centre
Paul Rogers, Berkshire Cancer Centre

Aims
Real-time prostate brachytherapy  has been used in a minority of UK centres since 2002. We report results from two UK centres prescribing to 160Gy for comparison with the pre-plan experience

Methods
Patients treated at Reading and Northampton Cancer Centres were prospectively registered on databases. Patient characteristics, PSA, staging, intra-operative and post-implant dosimetry, and follow-up data were recorded. Patients with a minimum of 12 months of follow were included. Toxicity, median 4-year PSA and 5-year bNED were calculated.

518 patients were registered between 2002 and 2010 (275 from Reading and 243 from Northampton). 79 (17.6%) patients with large prostates of 50-100mls were treated. Median follow up is 36 months (range 12 – 84). Patient and tumour characteristics were similar at both centres.

Results
5-year ASTRO bNED was 95.3% for low risk (NCCN definition), and 84.4% for intermediate risk. The median 4-year PSA was 0.1.  None of the large prostates have relapsed to date.

Intraoperative urethral D10 median was 202.9Gy (range 126.7-320.9), with a postoperative rise to 230Gy (118.5-395.9). Strictures occurred in 7 patients (1.4%). Re-catheterisation occurred in 1.4%, resulting in 3 TURPS (0.6%). Median IPSS pre-procedure was 4, peaked at 3 months to 11, and was settled at 5 by 12 months.

Median intraoperative D90 was 189.0Gy (162.6-214.7) at Reading and 188.0Gy (161.0-212.0) at Northampton; post-operative D90s were 173.3Gy (range 137.0-222.3), 170.0Gy (116.0-226.0) respectively, a median reduction in dose of 8.3% and 9.6%. 

Conclusion
The quality of the brachytherapy implant is an important predictor of long term outcome for both real-time and pre-plan techniques.
Real-time gives favourable post-implant D90s, with an 8.3% reduction in post-implant values, compared with 25-33% for pre-plan techniques. It is well tolerated, and allows successful treatment of larger prostates.

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6. Assessing the benefit of utilising higher activity seeds in larger prostate volumes

Wood D, Specialised Brachytherapy Radiographer, The Christie Hospital, Manchester
Morrissey N, Specialised Brachytherapy Radiographer, The Christie Hospital, Manchester
Logue J, Clinical Director, Clinical Oncology, The Christie Hospital, Manchester
Wylie J, Consultant, Clinical Oncology, The Christie Hospital, Manchester
Elliot PA, Consultant, Clinical Oncology, The Christie Hospital, Manchester

Introduction
The incidence of acute urinary morbidity following brachytherapy is higher with larger prostate volumes.  Although multi-factorial it is associated with the number of needles inserted (1) and the localised trauma of peri-urethral needle insertion and manipulation (2).  Our standard practise is to utilise a seed activity between 0.356-0.3609 mCi irrespective of pre-planned prostatic volume.  Although satisfactory for prostate volumes <50cc, to achieve acceptable dose distribution for prostates >50cc a much larger number of seeds and needles are required with the potential for heightened urinary morbidity.  We therefore explored the degree of needle sparing achieved when using a commonly available higher activity seed of 0.536 mCi in prostates >50cc.

Methods
Twenty patients with trans-rectal ultrasound measured prostate volumes between 50-69cc were retrospectively re-planned and checked by two independent radiographers using the increased activity I-125 seed. Patients were chosen based on chronological order of referral for prostate brachytherapy.  Needle number and prostate V100, V150, V200, rectal d100 and urethral d150 were specified and recorded as per current departmental protocol and compared against the actual delivered plan using our standard seed activity.

Results
By utilising the higher activity seed the mean needle number was reduced by 25% with no adverse effects on prostate V100, V150 and V200. Mean needle number was 32 with 0.356-0.369mCi seeds (range 26-35) compared to 24 with 0.536mCi (range 22-29).  The mean prostate V100 was 99.74% with 0.536mCi seeds compared to 99.56% with 0.356-0.369mCi seeds.  Urethral and rectal doses were slightly increased with higher activity seeds but remained within departmental limits.

Conclusions
Increasing seed activity to 0.536mCi resulted in far fewer needles being required to deliver the required PTV dose without exceeding dose constraints.  This simple manoeuvre may help reduce urinary morbidity when treating larger prostates. 

References
1) Lee N,et al; Int.J RadOncBioPhys2000 Dec1 485),1457-60
2) Eapen et al;RadOncBioPhysics2004 (0360-0316)59:51392-94

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7. Overview of 11 Years Experience in I-125 Prostate Brachytherapy.

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

Aim
The 11 year experience of I-125 LDR prostate brachytherapy in a UK centre is described.

Methods
Between March 1999 and September 2010, over 1700 patients underwent prostate brachytherapy, either as monotherapy or in combination with external beam radiotherapy (EBRT) and neoadjuvant hormones (NAH). Data were recorded on a bespoke prospective database. Survival analyses were performed on patients treated at least 3 years ago (n=1113). Outcomes were analysed by MSKCC risk grouping, treatment modality, PSA nadir and dosimetry. Biochemical relapse free survival (bRFS) was measured by the nadir+2 definition.

Results
The mean age was 64.1 (44-83) years. Median PSA follow up was 48(0-134) months. bRFS at 8 years was 84%. bRFS at 8 years for low, intermediate and high risk disease were 87%, 84% and 75% respectively. The use of EBRT did not influence bRFS in any risk group. The use of hormone therapy did not influence bRFS in low and intermediate risk groups. No significant association was seen with a D90 threshold of 130 or 140Gy, and bRFS. PSA nadir >0.5 was associated with decreased bRFS (p<0.0001). Baseline PSA and Gleason score were significant predictors of failure (HR 1.7, p<0.05 for both). Clinical stage was not a predictor of failure.

Conclusions
PSA nadir is a strong predictor of biochemical failure whether or not NAH were used. Patients with high risk disease remain biochemically controlled beyond any influence of hormonal therapy by combining EBRT with BXT. Monotherapy can be offered to selected intermediate risk patients. A durable relapse-free survival has been achieved in all risk groups by careful consideration of treatment strategy when assessing patients.

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The following abstracts were submitted and selected for poster presentation.

1. Sexually Transmitted Seeds?

Sarah Aldridge, Brachytherapy Physicist, Department of Medical Physics, Guy’s & St Thomas’ NHS Foundation Trust
David Gallacher, Radiation Protection Advisor, Guy’s & St Thomas’ NHS Foundation Trust
Janette Kinsella, Prostate Cancer Clinical Nurse Specialist, Guy’s & St Thomas’ NHS Foundation Trust
Ronald Beaney, Clinical Oncologist, Guy’s & St Thomas’ NHS Foundation Trust

Introduction:
Our centre offers prostate brachytherapy as a day case procedure. All patients treated receive radiation protection advice prior to their implant and also take home a card summarising this advice after the implant.
Recently a patient contacted our prostate cancer nurse specialist three weeks after implant informing her a lady he had been intimate with had reported symptoms of vaginal bleeding and a sore throat. He had not used a condom as advised during sexual activities and could this be a result of an implanted seed being transferred?

Method:
The patient and lady in question were asked to attend clinic the following day. Physics carried out a mini experiment to ascertain if a single seed could be detected within a person. This was done with a remaining seed from the batch used for the patients implant, several sheets of tissue equivalent material and a handheld scintillation radiation monitor, to determine the expected count rate at the surface of the body.

Results:
The lady attended clinic and after the team discussed the situation with her our brachytherapy physicist carried out a sweep of her body with the selected radiation monitor. No seed was detected with a high degree of certainty. Due to the small risk of ingestion of radioactive iodine from a compromised seed due to swallowing, a urine sample was also taken and measured in our gamma counter. No radiation was detected above background levels within the sample.

Conclusion:
The lady was referred to her GP for follow-up. The oncologist informed her GP by letter detailing the incident. This incident raised the issue of signed consent and we have since amended our signed patient consent form to specifically detail radiation advice given and understood. We have also updated our patient information leaflet to explain the responsibilities patients have for others after implant.

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2. 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.

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3. A single institution’s experience of cytoreductive regimens prior to prostate brachytherapy.

Roisin Connolly, Galway University Hospital
Aisling Barry,  Galway University Hospital
Frank Sullivan, Galway University Hospital

Aims/ Introduction:
Our study aimed to assess the percentage reduction in prostate volume with cytoreductive hormonal manipulation for patients who had prostate volumes of greater than 50mls prior to brachytherapy.

Materials/Methods:
Since 2008, Galway University Hospital has treated over 200 patients with prostate brachytherapy. From our hospital records we did a retrospective analysis comparing pre- and post-hormone prostate volumes in 23 patients who required cytoreductive treatment prior to brachytherapy. Therapeutic options used either alone or in combination were a 5-alpha reductase inhibitor (dutasteride), an anti-androgen (biclutamide) and a LHRH analogue (triptorelin). Treatment decisions were made at an individual patient level but in general LHRH analogues were avoided in patients who had moderately enlarged prostates (i.e. 50-75mls).

Results:
The greatest percentage volume reduction (median 37.5%) was seen in the triptorelin alone group, with the average pre-treatment volume for these patients being higher, at 67.78, than that of patients whose hormone regimen did not include triptorelin (59.94 ml). Our results indicated that patients whose cytoreductive regimen included triptorelin experienced greater problems with erectile dysfunction than the other groups. Patients who were treated with dutasteride and bicalutamide (n=8) achieved a satisfactory reduction in prostate volume in most cases (median 27.06%), with a shorter duration of treatment than the other groups (median 98 days). Of note, 2 patients did not have any reduction in volume with hormonal treatment.

Conclusion:
Our institution recommends the use of combination 5-alpha reductase inhibitor and anti-androgen therapy for volumes of 50-75mls. For those with prostate volumes of above 75mls, we advocate the use of a LHRH analogue alone or in combination.