E40
International Journal of Radiation Oncology Biology Physics
(DBM) were calculated using Kaplan-Meier estimates. A patient was counted as having a local recurrence if any of their treated lesions had a recurrence. Results: Median follow up was 6.8 months and median survival was 15.8 months. Eleven lesions received post-operative SRS to a surgical cavity and twenty-seven lesions received definitive SRS to a metastasis. Thirteen of the nineteen patients had either squamous cell carcinoma or undifferentiated carcinoma tumor histology. The median dose prescribed was 18Gy. One-year actuarial rate for LC was 77.3% (CI 44%-92%) while oneyear and two-year rates of OS were 52.9% (CI 28%-73%) and 31.7% (CI 11%-55%) respectively. The median time to develop DBM was 8.4 months with one-year actuarial rate of new BM being 64.9% (CI 39%-89%). Three patients (16%) underwent repeat SRS following development of new BM and three patients (16%) underwent salvage whole brain radiotherapy (WBRT). Conclusion: SRS may be utilized in the treatment of patients with primary head and neck malignancies metastasized to the brain with high efficacy. Those patients with well-controlled systemic disease and good performance status may benefit the most from definitive SRS while avoiding WBRT.
incorporate RT as a secondary intervention. Joinpoint regression modeling determined the rate of change of the introduction of new trials over time. Results: 340 trials met inclusion criteria. The majority were phase 2 (220 [64.7%]) and funded in combination by institutions and collaborative groups (nZ121[35.6%]). Monoclonal antibodies (mAb) were the most common immunotherapy (nZ152[44.7%]), with EGFR (nZ92[42.0%]) and checkpoint inhibitors (nZ66[30.1%]) being the most common. Seventy-five (22.1%) trials included radiation as a primary intervention, with 64 (85.3%) of these utilizing stereotactic body radiation (SBRT). All ITRT trials increased at a rate of 44.2% per year. Primary RT trials were more likely to utilize checkpoint inhibitors (p<0.01) and SBRT (p<0.01), and more likely to involve lung (p<0.01) or metastatic sites (p<0.01). Primary RT trials increased steadily at a rate of 25.2% per year and trended toward higher use of checkpoint inhibitors and SBRT in later years. Secondary RT trials had an inflection point in 2006, increasing 50.1% per year prior to 2006 and decreasing 4.9% per year afterwards. Conclusion: The rate of new ITRT clinical trials is increasing over time, with trials evaluating RT as the experimental intervention increasing significantly. Checkpoint inhibitors and SBRT are important components among new ITRT trials.
(P091) Stereotactic Body Radiation Therapy for Adrenal Gland Metastases Kristin A. Plichta, MD, PhD, Nathaniel B. Camden, BS, Bryan G. Allen, MD, PhD, and John M. Buatti, MD; University of Iowa Hospitals and Clinics
(P093) Palliative Radiation for Bone Metastases From Hepatocellular Carcinoma: Practice Patterns and the Implications of Fraction Scheme on the Amount of Remaining Life Spent Receiving Treatment Ryan K. Schmid, BS, Abdulrahman Y. Hammad, MD, Candice Johnstone, MD, MPH, T.C. Gamblin, MD, MS, and Jared R. Robbins, MD; Medical College of Wisconsin
The adrenal gland is a common site for metastatic disease, and recent reports have suggested stereotactic body radiation therapy (SBRT) to the adrenal gland is safe and well-tolerated. To further investigate the use of SBRT for adrenal metastases, we evaluated outcomes from relevant patients at our institution. Eleven patients received SBRT to adrenal metastases between 2006-2016. Patients eligible for SBRT included those with limited metastatic disease and those with otherwise controlled metastatic disease and uncontrolled adrenal metastases. Local control, disease free survival, overall survival, toxicity and relief from pain were evaluated. One patient died from an unrelated cause during SBRT. Of the ten remaining patients, median overall survival was 9.9 months, and median disease free survival was 3.4 months. 70% of patients achieved local control in the adrenal gland. In terms of toxicity, four patients developed nausea, two patients developed fatigue and one patient report loose stools. One patient developed a GI bleed three months after completion of SBRT. Four patients reported back and/or flank pain prior to treatment, and all four reported decreased pain after SBRT. SBRT appears to be a safe and effective means to treat adrenal tumors, with satisfactory local control, a limited side effect profile and good pain control with treatment. However, serious adverse events can occur, and overall survival appears to be short. Further large scale studies are needed to determine the acceptable dose parameters in terms of efficacy and toxicity. (P092) A Comprehensive Analysis of Clinical Trials Including Both Radiation Therapy and Immunotherapy Dustin Boothe, MD,1 Michael Christensen,2 and Shane Lloyd, MD1; 1 University of Utah, Department of Radiation Oncology, 2University of Utah, School of Medicine Purpose: Preclinical data suggest that radiation therapy (RT) may enhance the response to cancer immunotherapies. However, clinical trial data will be needed to validate this new paradigm. The purpose of this study was to investigate recent trends in clinical trials that combine immunotherapy and radiation therapy (ITRT). Methods: We queried clinicaltrials.gov for ITRT clinical trials initiated since 2002 using both radiation and immunotherapy in tandem as mandated interventions. We designated the trials that examine the specific aspects of RT or its abscopal properties as “primary RT” trials. Chi-squared analysis determined differences between primary RT trials and those that
Background: Palliative radiation therapy (RT) for bone metastases is a common practice. Countless studies show palliative equipoise between single and multiple fraction regimens. We examine practice trends in the use of palliative RT to bone and the impact of dose scheme on outcomes in hepatocellular carcinoma (HCC) patients. Methods: Patients with HCC metastases to the bone who received RT were identified from the National Cancer Database (2004-2013). The percentage of remaining life spent receiving RT (PRLSRT) was calculated by dividing the elapsed days of RT by the number of days they survive from starting RT to death. Results: A total of 1331 patients met the inclusion criteria. Median patient age was 61 years (20-90). Treated metastasis sites included the spine (62.3%), hip/pelvis (18.5%) and shoulder/extremity (10.5%). Common dose fractionations included: 30 Gy in 10 fractions (36.3%), 35 Gy in 14 fractions (7.43%), 37.5 Gy in 15 fractions (7.13%), 20 Gy in 5 fractions (4.73%) and 8 Gy in 1 fraction (1.95%). Just 3.7% of patients received 1 fraction, while 34% received >10 fractions. ASTRO approved regimens were administered in 43%. For this entire cohort, median OS after palliative RT was 2.87 months. After RT 30.8% died within 1 month. By fraction number, the median overall survival, and the mean and median PRLSRT were as follows: 1 fraction (1.1 months, 8.9%, and 3%), 2-5 fractions (0.6 months, 32.3%, and 23.5%), 6-10 fractions (2.8 months, 27.3%, and 15.9%) and >10 fractions (4.5 months, 24.4%, and 14.4%). Conclusion: Despite no palliative benefit for multiple fraction regimens, there was a vast underutilization of single fraction treatments, which resulted in a significant PRLSRT for many patients. A realistic understanding of prognosis and the implications of dose scheme may help ensure patients do not spend the majority of their limited days receiving unwarranted palliative treatments.
(P094) Financial Conflicts of Interest Are Correlated With Publication Productivity Among Academic Radiation Oncologists Nicholas G. Zaorsky,1 Awad A. Ahmed, MD,2 Clifton D. Fuller, MD,3 Charles R. Thomas, Jr, MD,4 and Emma B. Holliday, MD3; 1Fox Chase Cancer Center, 2University of Miami, 3The University of Texas MD