20 Prostate Cancer

Prostate Cancer

3

THE GEC ESTRO HANDBOOK OF BRACHYTHERAPY | Part II: Clinical Practice Version 1 - 01/12/2014

20 Prostate Cancer

Peter Hoskin, György Kovacs, Marco van Vulpen, Dimos Baltas

1. Summary 2. Introduction

3 3 4 5 5 6 7 8

9. Treatment planning

10 10 13 14 16 18 18

10. Dose, dose rate, fractionation

3. Anatomical Topography

11. Monitoring

4. Pathology 5. Work Up

12. Results

13. Adverse side effects 14. Key messages

6. Indications and Contraindications

7. Target Volume 8. Technique

15. References

1. SUMMARY

indolent and therefore not clinically significant. The recent PIV- OT trial [2] demonstrated in men with localized prostate cancer that radical prostatectomy did not significantly reduce all-cause or prostate-cancer mortality, as compared with observation, through at least 12 years of follow-up. However, subgroup analy- ses did reveal that radical prostatectomy improved all cause mor- tality for patients with a PSA >10 ng/ml and there was a trend for improved all cause survival for intermediate and high risk patients [2]. This study suggests that overtreatment occurs for patients with low risk prostate cancer. Due to the psychological burden of the disease, many patients prefer treatment and will accept potential toxicity. In recent years, there have been signifi- cant improvements in the management of localized prostate can- cer using brachytherapy, external beam radiotherapy or surgery but the optimal treatment remains undefined. In the absence of prospective clinical trials, survival and biochemical control data are difficult to assess and quality of life issues have consequent- ly gained increasing importance in the choice of interventional therapy for individual patients. Brachytherapy has the potential advantages of convenience, effectiveness, and relatively low mor- bidity. has been established in low, intermediate and high risk dis- ease in combination with external beam radiotherapy. HDR brachytherapy alone in prostate cancer is gaining ground with increasing evidence for its efficacy in all risk groups. Recognised side effects include acute urinary outflow symp- toms with a 5-10% incidence of short term catheterization, erectile dysfunction in around 30% and late urethral strictures in 5-8%. Compared to radical prostatectomy brachytherapy results suggest lower incidences of urinary symptoms and erectile dysfunction and compared to external beam radio- therapy very low bowel toxicity and no incidence of second malignancies. New developments in prostate brachytherapy include its use in salvage treatment following relapse in patients who re- ceived prior radiotherapy and focal brachytherapy either as an integrated boost to subvolumes within the CTV or as true focal therapy of localized tumour within the gland.

2. INTRODUCTION Prostate cancer is a disease of ageing men being rare under the age of 45 years but with an incidence which rises with age, post mortem series showing malignant changes in up to 100% of men over 80 [1]. It is more common in urban than rural communi- ties; it has been related to a high fat and meat diet and is more common in married men than never married men. The risk is increased up to three fold in men with a first degree relative hav- ing prostate cancer and there is a five fold risk in carriers of the BRCA-2 gene. Other genetic changes have been identified asso- ciated with prostate cancer of which the most common is meth- ylation of the promoter GSTP1 involved in carcinogen detoxifi- cation. The overall incidence of prostate cancer is rising, partly attributed to an ageing population and increased measurement of PSA levels in asymptomatic men, despite the absence of good evidence to support screening. Especially favourable risk prostate cancer is common in elderly men in developed countries. These cancers are often biologically Brachytherapy is now established as an effective treatment for prostate cancer alongside radical prostatectomy and exter- nal beam radiotherapy. The ultrasound guided transperineal approach has been developed to combine real time imaging of the implantation with one step dosimetry ensuring con- sistently high standards of implant quality which is related to outcome. Brachytherapy has the physical advantage of being able to concentrate a high radiation dose in the target with high conformality minimizing doses to organs at risk. HDR brachytherapy delivered in large doses per fraction also ex- ploits the low alpha beta ratio of prostate cancer delivering very high equi-effective doses in excess of 100Gy (EQD2). Low dose rate permanent implants give best outcomes with low and intermediate risk prostate cancer and in combina- tion with external beam radiotherapy are effective for high risk disease. HDR temporary afterloading brachytherapy