Stereotactic Body Radiotherapy for Oligoprogression in Castration-Resistant Prostate Cancer: Early Toxicity Analysis...

Area of Science:

• Oncology
• Radiation Oncology
• Prostate Cancer Research

Background:

• Metastatic castrate-resistant prostate cancer (CRPC) patients on androgen receptor targeted agents (ARTA) can develop oligoprogressive disease (OPD).
• Stereotactic body radiotherapy (SBRT) is a potential treatment for limited metastatic sites.

Purpose of the Study:

• To evaluate the toxicity and impact on quality of life of SBRT for OPD in CRPC patients receiving ARTA.
• To assess if SBRT to OPD sites improves progression-free survival.

Main Methods:

• Phase II clinical trial enrolling CRPC patients with ≤ 2 oligoprogressive lesions on abiraterone or enzalutamide.
• Patients received SBRT (30 Gy in 5 fractions) to OPD sites while continuing ARTA.
• Toxicity assessed via Common Terminology Criteria for Adverse Events (CTCAE) and Radiation Therapy Oncology Group (RTOG) criteria; quality of life via visual analogue scale (VAS) and EQ-5D.

Main Results:

• Twenty percent (8/40) of patients experienced grade ≥ 3 toxicity, with only 2.5% (1/40) possibly related to SBRT.
• No significant difference was observed in mean EQ-5D or VAS scores from baseline to post-SBRT timepoints (p = 0.449).

Conclusions:

• SBRT for OPD in CRPC patients on ARTA is associated with low rates of severe toxicity.
• SBRT treatment did not discernibly alter patient-reported quality of life.
• Further follow-up is ongoing to report final progression-free survival and toxicity data.