There is increasing worldwide interest in exploring stereotactic ablative body radiotherapy (SABR) for treating metastases in men with prostate cancer, including for the treatment of oligoprogressive metastases. The latter applies to a situation whereby patients with widespread metastases undergoing systemic therapy present with a solitary or a few metastatic tumors that progress, while all other metastases are stable or responding. The usual practice would be to change systemic therapy at this point, but another approach is to locally ablate the "rogue" metastases and continue the same systemic therapy. SABR used in this scenario may delay the need to switch to another line of systemic therapy and improve progression-free survival while patients stay on the same systemic therapy.
ECOG performance status 0-1.
Histologic confirmation of prostate adenocarcinoma.
Documentation of metastatic, castration-resistant prostate cancer.
Patient being treated with abiraterone.
Patients presenting with unequivocal clinical progression, defined as one of the following: (i) cancer pain requiring the initiation of opioid therapy; (ii) immediate need for cytotoxic chemotherapy as per treating physician's discretion; or (iii) deterioration of performance status to grade ≥ 3 according to ECOG.
Evidence of spinal cord compression.
Prior malignancy within the past 5 years, excluding non-melanoma skin cancer, and in-situ cancer.