Metastasis-directed radiation therapy after radical cystectomy for bladder cancer

Purpose: Metastasis-directed radiation therapy (MDRT) may improve oncologic and quality of life outcomes in patients with metastatic cancer, but data on its use in metastatic bladder cancer is severely limited. We sought to review our institutional experience with MDRT in patients with metastatic bladder cancer following radical cystectomy. Materials and Methods: We reviewed records of patients who underwent radical cystectomy and subsequent MDRT at our institution between 2009 and 2020. Baseline demographic and clinical/pathologic factors were collected, as were details of treatment including systemic therapy and MDRT. Cases were categorized by treatment intent as consolidative (intended to prolong survival) and palliative (intended only to relieve symptoms). Response to treatment, survival, and toxicity outcomes were reviewed. Results: A total of 52 patients underwent MDRT following radical cystectomy. MDRT was categorized as consolidative in 40% of cases and palliative in 60%. Toxicity (CTCAE Grade ≥ 2) was reported in 15% of patients, none of which exceeded Grade 3. Most patients undergoing consolidative MDRT were treated with SBRT techniques (76%) and a majority (67%) received concurrent treatment with an immuno-oncology agent. Among patients treated with consolidative intent, 2-year progression-free and overall survival were 19% and 60%, respectively. Conclusion: MDRT is safe and well-tolerated by a majority of patients. A majority of patients treated with consolidative intent survived ≥ 2 years from treatment.