Post-prostatectomy radiation therapy: Consensus guidelines of the Australian and New Zealand Radiation Oncology Genito-Urinary Group

doi:10.1016/j.radonc.2008.05.006

Radiotherapy and Oncology

Volume 88, Issue 1, July 2008, Pages 10-19

https://doi.org/10.1016/j.radonc.2008.05.006 Get rights and content

Abstract

Background and purpose

Three randomised trials have demonstrated the benefit of adjuvant post-prostatectomy radiotherapy (PPRT) for high risk patients. Data also documents the effectiveness of salvage radiotherapy following a biochemical relapse post-prostatectomy. The Radiation Oncology Genito-Urinary Group recognised the need to develop consensus guidelines on to whom, when and how to deliver PPRT.

Materials and methods

Draft guidelines were developed and refined at a consensus conference in June 2006 attended by 63 delegates where urological, radiotherapy and diagnostic imaging experts spoke on aspects of PPRT. Unresolved issues were further developed by working parties and redistributed until consensus was reached.

Results

Central to the recommendations is that patients with positive surgical margins, seminal vesicle invasion and/or extracapsular extension have a high risk of residual local disease and should be informed of the options of either immediate adjuvant radiotherapy or active surveillance with early salvage in the event of biochemical recurrence. Salvage radiotherapy should be instituted at the earliest confirmation of biochemical recurrence. Detailed contouring guidelines have been developed, defining the regions at risk of residual microscopic disease which should be included in the clinical target volume. The recommended doses are 60–64 Gy for adjuvant, and 60–66 Gy for salvage radiotherapy. The role of hormone therapy in conjunction with PPRT is yet to be defined.

Conclusions

These consensus guidelines have been developed to give clinical and technical guidance to radiation oncologists and urologists in the management of high risk post-prostatectomy patients.

Section snippets

Materials and methods

Specialists in radiation oncology, urology, radiation therapy and medical physics from Australia, New Zealand and Singapore were invited to attend a two days consensus workshop. The radiation oncologists were also invited to complete a survey of their current post-prostatectomy practice. Selected international and local expert speakers from the disciplines of radiation oncology, urology and radiology presented data on topics relevant to post-prostatectomy radiotherapy. Prior to the conference,

Results

The consensus workshop convened on 2nd and 3rd June 2006 in Kingscliff, New South Wales. The workshop was attended by 63 delegates comprising representatives from radiation oncology, urology, radiology, medical physics and radiation therapy. Consensus was achieved on most issues, however, further development of the technical specifications of the radiotherapy target volumes was required and this was further developed by a working party after the workshop. The final consensus guideline

Discussion

A radical prostatectomy is an effective oncological procedure in appropriately staged patients, resulting in cancer control for most men with organ confined prostate cancer so treated [9], [10]. Despite this, approximately 15–40% of men treated by radical prostatectomy will experience a biochemical recurrence within 10 years after surgery [11], [12], [13]. A number of perioperative factors have been identified which prognosticate the risk of biochemical failure following a prostatectomy [14],

Conclusion

Collaborative trial groups in the United Kingdom [55] and Australia/New Zealand [56] are each conducting randomised trials to investigate which approach, immediate adjuvant or early salvage radiotherapy, is superior in the post-prostatectomy setting for patients with adverse pathological factors. The UK RADICALS trial is also investigating the role of androgen deprivation therapy in this setting. Until these trials are completed, patients should be made aware of the respective benefits and

Acknowledgements

The authors thank Tom Pickles, Peter Swindle and Alain Lavoipierre for their invaluable contribution to the development of the guidelines.

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The European Association of Urology (EAU) proposed a risk stratification (high vs. low risk) for patients with biochemical recurrence (BR) following radical prostatectomy (RP). Here we investigated whether this stratification accurately predicts outcome, particularly in patients staged with PSMA-PET.
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The median follow-up time after SRT was 31.0 months. The 3-year biochemical progression-free survival (BPFS) was 85.7 % in EAU low-risk versus 69.4 % in high-risk patients (p = 0.002). The 3-year metastasis-free survival (MFS) was 94.4 % in low-risk versus 87.6 % in high-risk patients (p = 0.005). The 3-year overall survival (OS) was 99.0 % in low-risk versus 99.6 % in high-risk patients (p = 0.925). In multivariate analysis, EAU risk group remained a statistically significant predictor of BPFS (p = 0.003, HR 2.022, 95 % CI 1.262–3.239) and MFS (p = 0.013, HR 2.986, 95 % CI 1.262–7.058).
Our data support the EAU risk group definition. EAU risk grouping for BCR reliably predicted outcome in patients staged lymph node-negative after RP and with PSMA-PET before SRT. To our knowledge, this is the first study validating the EAU risk grouping in patients treated with PSMA-PET-planned SRT.
Prostate-Specific Membrane Antigen Positron Emission Tomography/Computed Tomography-Based Clinical Target Volume Delineation Guideline for Postprostatectomy Salvage Radiation Therapy: The PERYTON Guideline
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Prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) scan is the standard imaging procedure for biochemical recurrent prostate cancer postprostatectomy because of its high detection rate at low serum prostate-specific antigen levels. However, existing guidelines for clinical target volume (CTV) in prostate bed salvage external beam radiation therapy (sEBRT) are primarily based on experience-based clinical consensus and have been validated using conventional imaging modalities. Therefore, this study aimed to optimize CTV definition in sEBRT by using PSMA PET/CT–detected local recurrences (LRs).
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After central review, 93 LRs were identified on 83 PSMA PET/CTs. The proposed CTV definition improved the coverage of PSMA PET/CT–detected LRs from 67% to 96% compared with the GFRU-CTV, while reducing the GFRU-CTV by 25%. The new CTV was highly reproducible, with a mean DSC of 0.82 (range, 0.81-0.83).
This study contributes to the optimization of CTV definition in postprostatectomy sEBRT by using the pattern of LR detected on PSMA PET/CT. The PERYTON-CTV is highly reproducible across the participating centers and ensures coverage of 96% LRs while reducing the GFRU-CTV by 25%.
Development of Prostate Bed Delineation Consensus Guidelines for Magnetic Resonance Image-Guided Radiotherapy and Assessment of Its Effect on Interobserver Variability
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Prostate-specific membrane antigen positron emission tomography leads to management changes in one-third of patients receiving salvage radiotherapy for post-radical prostatectomy biochemical recurrence of prostate cancer.

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GuidelinesPost-prostatectomy radiation therapy: Consensus guidelines of the Australian and New Zealand Radiation Oncology Genito-Urinary Group

Abstract

Background and purpose

Materials and methods

Results

Conclusions

Section snippets

Materials and methods

Results

Discussion

Conclusion

Acknowledgements

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Guidelines
Post-prostatectomy radiation therapy: Consensus guidelines of the Australian and New Zealand Radiation Oncology Genito-Urinary Group