Stereotactic ablative radiotherapy (SABR) may help improve progression-free survival (PFS) and delay the need for systemic therapy in men with oligometastatic prostate cancer, according to a study presented at the Genitourinary Cancers Symposium in San Francisco.
Investigators conducted a study with 18 patients with relapsed oligometastatic prostate cancer and found that SABR may be beneficial and improve quality of life.
“Metastases-directed therapy (MDT) is one of the hottest topics in the management of advanced prostate cancer. The question is, can we do more to improve disease control, quality of life, and maybe cure some of the patients who relapse with few metastatic sites, up to three sites in this study,” said study investigator Ahmed El-Modir, MD, consultant oncologist at University Hospital Birmingham and Birmingham University, Birmingham, United Kingdom.
Dr. El-Modir and colleagues assessed both the efficacy and toxicity of SABR for oligometastatic recurrence. The oligometastatic state is considered an intermediate stage of cancer spread between localized disease and widespread metastases. The retrospective analyses looked at local control, biochemical progression-free survival (b-PFS), toxicity, and systemic therapy-free survival. Among the 18 patients, 26 lesions were treated with SABR, delivered using both CyberKnife and volumetric-modulated arc therapy.
In this cohort, clinicians used doses of 24 Gy in two or three fractions for spine and 30-40 Gy in three fractions for lymph nodes and other bony metastases. All patients were imaged prior to treatment and responses were determined by PSA testing and repeat scanning. The authors prospectively recorded acute and late toxicities using the Common Terminology Criteria for Adverse Events.