An algorithm for managing the failure of external beam radiotherapy in prostate cancer

To present a management algorithm for men with prostate cancer recurring after external beam radiotherapy (EBRT), based on a review of published reports, to assist clinicians in identifying men who are suitable for salvage therapy and to help them to decide which type of salvage treatment is most likely to confer the desired outcome with the minimum of harm.

Men with radiorecurrent prostate cancer require special consideration; they tend to be older, have more comorbidity and have worse disease than their contemporaries having primary treatment. Salvage treatment is compromised by the irradiated pelvis, resulting in increased treatment toxicity. Using the Pubmed database and reference lists of key articles, we identified studies relating to the management of radiorecurrent prostate cancer; the findings were incorporated into a management algorithm and summary table of treatments.

The American Society for Therapeutic Radiology and Oncology criteria, which define biochemical failure has now been superseded by the Phoenix definition (nadir prostate-specific antigen [PSA] plus 2 ng/mL). Biochemical follow-up after EBRT should be 3-monthly until the PSA level has reached a stable nadir after withdrawing androgen suppression. Contrast-enhanced dynamic magnetic resonance imaging (MRI) is an accurate tool and can be used for both the diagnosis and staging of patients with prostate cancer, in conjunction with prostate biopsies. Prostate biopsies should only be considered >2 years after EBRT to avoid false-positive results. In addition to MRI, high-risk cases being considered for salvage therapy should be considered for laparoscopic lymph-node dissection to exclude micrometastases. Deferred androgen suppression, laparoscopic or open radical prostatectomy, cryotherapy and high-intensity focused ultrasound all seem reasonable salvage treatment approaches.

Through improved methods of detection, including frequent PSA measurements, modern imaging and carefully obtained biopsies, those with radiorecurrent disease can be identified before their disease has spread. Rigorous staging will exclude those with micrometastases. The minimally invasive salvage therapies seem to offer an advantage over salvage surgery to patients in whom the benefits and harms are so finely balanced.