Postoperative radiation therapy after radical prostatectomy

Prostate cancer is the most diagnosed cancer in men, with its incidence mainly dependent on age.  Clinically localised prostate cancer can be treated with radical prostatectomy or radiation therapy and in Australia surgery is more common. After prostatectomy treatment there is always some risk of local recurrence and this is greater among men with extraprostatic extension, high-grade cancer, seminal vesicle invasion and/or positive surgical margins.

The treatment options for men who have undergone a radical prostatectomy and have a high-risk of recurrence include post operative ‘adjuvant’ radiation therapy to the prostate bed in men with high-risk pathological features and no detectable PSA or, alternatively, observation with early salvage radiation therapy to the prostate bed in men with a rising or detectable PSA.

• Adjuvant radiation therapy: defined as post-operative radiation therapy in men who receive radiation therapy as an ‘adjunct’ to the primary surgery, because of these high-risk pathological features, prior to a detectable increasing PSA. Adjuvant radiation therapy is usually administered within four to six months following radical prostatectomy after the return of acceptable urinary control. 
• Early salvage radiation therapy: defined as men who receive post-operative radiation therapy following progressing PSA (commonly defined as PSA greater or equal to 0.2ng/mL), without importantly, a specific PSA threshold does not need to be met prior to starting treatment. Once the decision for early salvage radiation therapy has been made, treatment should be given as soon as possible.  

Routine adjuvant radiation therapy is no longer the preferred practice for men with high-risk of recurrence post radical prostatectomy, rather it appears men have a similar chance of cancer control if they are followed up after surgery and early salvage radiation therapy is administered only if a rise in PSA is detected.

Evidence suggests this change in practice avoids approximately 50% of men receiving unnecessary postoperative radiation therapy, sparing them from potential radiation therapy-related side effects.

Early salvage radiation therapy is the standard of care for patients following radical prostatectomy when PSA 0.1-0·20 ng/mL. A specific PSA threshold does not need to be met prior to starting treatment. Once the decision for early salvage radiotherapy has been made, treatment should be given as soon as possible because studies show a clear relationship between commencing radiation therapy at higher PSA levels (>0.2) and lower disease control rates. 

PSA surveillance intervals post radical prostatectomy

PSA should be measured every 3 months in the first year following prostatectomy, then every 6 months until 3 years, and yearly thereafter.

Adjuvant radiation post radical prostatectomy remains a treatment option in highly selected patients with at least two out of three high-risk pathological features, including:

• pT3: extends through prostate capsule, PT3a Extracapsular extension (unilateral or bilateral), pT3b Tumour invades seminal vesicle(s)  
• R1: positive surgical margins   

• ISUP > 3:   

• International Society of Urological Pathology (ISUP) 2014 system for grading of prostate cancer   
• 1 (least aggressive) to 5 (most aggressive) 

Routine administration of adjuvant radiation for men with high-risk pathological features post radical prostatectomy is no longer standard practice. 

Early salvage radiation therapy is recommended for patients following radical prostatectomy when there is a rising PSA. 

Adjuvant radiation following radical prostatectomy may still be considered for select patients at particularly high risk of PSA recurrence.

Guidance supplement

Guidance development is underpinned by the Safer Care Victoria evidence-based guidance strategy. This guidance supplement details the rigorous guidance development methodology. 

Clinicians and patients/carers should discuss and decide on the most appropriate method(s) of treatment.    

Where possible, telehealth and shared-care arrangements with the patient’s local GP should be made available. 

Patients with a rising PSA following radical prostatectomy should be referred for early discussion with a radiation oncologist. The opportunity to discuss the benefits and limitations of salvage radiation therapy may reduce unwarranted variations in care.

1. Australian Institute Health and Welfare. 2021. Cancer Data in Australia. http://www.aihw.gov.au/  
2. European Association of Urology. Prostate Cancer Guidelines. 2021. https://uroweb.org/guideline/prostate-cancer/#6_2   
3. Vale CL, et al. ARTISTIC Meta-analysis Group. Adjuvant or early salvage radiotherapy for the treatment of localised and locally advanced prostate cancer: a prospectively planned systematic review and meta-analysis of aggregate data. 2020. Lancet. 396(10260):1422-1431. https://pubmed.ncbi.nlm.nih.gov/33002431/ 
4. Kneebone, Fraser-Browne et al. Adjuvant radiotherapy versus early salvage radiotherapy following radical prostatectomy (TROG 08.03/ANZUP RAVES): a randomised, controlled, phase 3, non-inferiority trial. 2020. The Lancet Oncology. 21(10), 1331–1340.  
5. Abugharib, A. et al. Very early salvage radiotherapy improves distant metastasis-free survival. 2017 (Mar) Journal of Urology. https://doi.org/10.1016/j.juro.2016.08.106