755 Background: Patients with metastatic colorectal cancer undergoing systemic therapy may enter an oligoprogressive state. Traditionally, local ablative therapy (LAT) has been limited to symptom palliation. We hypothesize that LAT for oligoprogressive lesions with stereotactic body radiation therapy (SBRT) is a feasible alternative to surgical interventions and may delay progression of disease. Methods: An IRB-approved retrospective review of patients with oligoprogressive, metastatic colorectal cancer who were treated with SBRT at Georgetown University Hospital from 2012-2016 was performed. Results: 40 patients with 41 metastatic lesions of the lung (n = 11), liver (n = 10), lymph nodes (n = 8), soft tissue (n = 6), and bone (n = 6) were reviewed. Median follow-up, overall survival, and freedom from distant progression were 10.6, 17.3, and 6.4 months, respectively. Crude one year local control and overall survival were 82.9% and 75%, respectively. First site of progression was distally in 63.4% of patients. Patients treated with SBRT in the liver were significantly more likely to locally progress than other treated sites (13.18 vs. 39.81 months, p = 0.007). On univariate analysis, non-lymph node treated tumors (p = 0.046), larger CEA change at 6 month follow-up (p = 0.048), and right sided primary tumors (p = 0.004) were associated with local failure within 1 year. On multivariate analysis, only right sided primary tumors were significantly more likely to locally progress (p = 0.009). Conclusions: Patients with oligoprogressive colorectal cancer can be effectively treated with SBRT to achieve acceptable rates of local control and potentially delay progression of disease.
Considerations in Orbital Exenteration
