What is the chance of cure with Whole Pelvic Radiation Therapy (WPRT) for oligometastatic prostate cancer after Radical Prostatectomy (RP)?

From the Guidelines

The chance of cure with Whole Pelvic Radiation Therapy (WPRT) for oligometastatic prostate cancer after Radical Prostatectomy (RP) is low to moderate, with a reported 6-year biochemical progression-free survival rate of around 32% to 48% in selected patients with low pre-salvage radiation PSA levels [ 1 ].

Key Factors Influencing Cure Rates

• Pre-salvage radiation PSA level: Lower levels (< 0.5 ng/ml) are associated with better outcomes [ 1 ]
• Gleason score: Higher scores (8-10) are associated with poorer outcomes [ 1 ]
• Surgical margins: Positive margins are associated with increased risk of biochemical recurrence [ 1 ]
• PSA doubling time: Shorter doubling times (< 10 months) are associated with poorer outcomes [ 1 ]

Treatment Considerations

• Salvage radiotherapy: Should be considered for patients with PSA or local recurrence after RP, in the absence of distant metastatic disease [ 1 ]
• Adjuvant radiotherapy: May be beneficial for patients with adverse pathologic features, such as positive margins or extracapsular extension [ 1 ]
• Androgen deprivation therapy (ADT): May be considered for patients with high-risk features or evidence of metastatic disease [ 1 ]

From the Research

Whole Pelvic Radiation Therapy (WPRT) for Oligometastatic Prostate Cancer

• The chance of cure with WPRT for oligometastatic prostate cancer after Radical Prostatectomy (RP) is supported by several studies 2, 3, 4, 5.
• A study published in 2023 found that WPRT improves survival free from relapse, and no recurrences were observed in the pelvis, although the trial was closed early due to poor enrollment 2.
• Another study from 2007 compared WPRT to prostate bed RT (PBRT) after radical prostatectomy and found that WPRT resulted in superior biochemical relapse-free survival (bRFS) compared to PBRT, particularly for high-risk patients 3.
• A systematic review and meta-analysis published in 2021 found that WPRT significantly improved 5-year biochemical failure-free survival (BFFS) and progression-free survival (PFS) compared to prostate-only radiotherapy (PORT) 4.
• A retrospective study from 2024 investigated the use of dose-escalated salvage WPRT with the simultaneous integrated boost (SIB) technique in patients with biochemical recurrence after radical prostatectomy for high-risk prostate cancer and found a 5-year biochemical progression-free survival rate of 72% 5.

Toxicity Associated with WPRT

• The studies also reported on the toxicity associated with WPRT, including increased risk of acute and late gastrointestinal (GI) toxicity 2, 4 and genitourinary (GU) toxicity 4, 5.
• However, the majority of toxicities were grade 2 or lower, and the incidence of grade 3 or higher toxicities was relatively low 2, 4, 5.

Oligometastatic Prostate Cancer Treatment

• The treatment of oligometastatic prostate cancer is a complex and multifaceted issue, and the role of WPRT in this setting is still being defined 6.
• A study from 2019 noted that oligometastatic prostate cancer may be considered as the last border of possibly curable disease, and that a multimodal approach, including surgery and radiation therapy, may offer opportunities to eradicate the tumor or delay its progression 6.