(PZ.011) in the 20-30 Gy, 30-40 Gy, and > 40 Gy ROIs, respectively. Conversely, the overall effect of age, gender, and use of chemotherapy were not significant. Conclusion: The significant reduction of femoral head CTh of up to 15% seen in patients receiving EBRT in the acute setting presents a possible mechanism for radiation induced fracture. This suggests CTh may be a potential marker for radiation induced PIF. Early CTh loss appears to be primarily affected by radiation exposure. Further research is needed evaluating the correlation between CTh and incidence of fracture. Author Disclosure: D.M. Randolph: None. C. Okoukoni: None. S. Isom: None. M.T. Munley: None. B.E. Lally: None. A. Blackstock: None. J. Willey: None. 3229 Acute and Chronic Complications After Abdominal/Pelvic Radiation in Patients With Inflammatory Bowel Disease R.M. Rhome, J. Axelrad, S. Itzkowitz, N. Harpaz, J.F. Colombel, C. Ang, and M. Buckstein; Icahn School of Medicine at Mount Sinai, New York, NY Purpose/Objective(s): There is limited data informing the safety of ra- diation therapy (RT) for cancer in patients with inflammatory bowel dis- ease (IBD). The purpose of this study was to compare the prevalence of at least grade 2 acute and long-term complications associated with abdom- inal/pelvic RT among IBD patients receiving RT, compared to RT-naive IBD patients being treated for similar malignancies. Materials/Methods: We identified 64 patients with IBD (47% ulcerative colitis, 53% Crohn’s disease) with an abdominal or pelvic malignancy treated with curative intent. The site of malignancy included prostate cancer (35.9%), rectal cancer (18.8%), anal cancer (17.2%), colon cancer (14.1%), hepatobiliary (6.3%), urologic cancers (4.7%), pancreatic cancer (1.6%), and cervical cancer (1.6%). External beam radiation therapy (EBRT) and select brachytherapy were included as treatment with RT. We looked at oncologic treatment regimens and acute/chronic IBD compli- cations. Only grade 2 or higher chronic toxicities were explored: new fistulas, strictures, IBD flares requiring hospitalization, or outpatient flares requiring medication escalation. Patients who received RT as part of their treatment course were compared to patients who did not receive radiation. Unpaired t-test and Fisher exact test were used to compare cohorts. Results: Of the 64 patients with IBD identified, 42 patients were treated with RT with curative intent for an invasive malignancy and 22 patients treated without (median age 65 vs. 63, respectively). A median EBRT dose of 5040 cGy was used. Median follow-up was 44.6 months for the RT group and 47.9 months in the non-RT group. Long-term complications are detailed in the table below. At the time of this analysis, 57 patients were still alive, and no patients died from complications related to IBD. In the RT group, the median dose in patients with any chronic IBD complication was not significantly different from those without IBD complications (pZNS). With respect to acute toxicities during RT, 23.3% of patients developed increased frequency of bowel movements requiring medication while on treatment. There was no difference in the median dose in patients with acute bowel toxicities and the dose in patients without acute bowel toxicity (PZNS). No acute toxicities required hospitalization. Conclusion: When compared to patients with similar malignancies not treated with radiation, the absolute rate of acute radiation toxicities and long-term IBD complications after RT does not appear to be significantly different. Radiation dose did not predict incidence of acute or long-term complications. Larger prospective trials are needed to validate these findings. Author Disclosure: R.M. Rhome: None. J. Axelrad: None. S. Itzkowitz: None. N. Harpaz: None. J. Colombel: None. C. Ang: None. M. Buck- stein: None. 3230 A Phase 1 Trial of Stereotactic Ablative Radiation Therapy (SABR) for Oligometastatic Cancer: Toxicity and Quality of Life D. Erler, 1 P. Cheung, 2 A. Sahgal, 2 H.T. Chung, 3 I. Poon, 2 W. Chu, 1 L. Zhang, 1 G. Bedard, 1 N. Pulenzas, 4 and E. Chow 5 ; 1 Sunnybrook Health Sciences Centre-Odette Cancer Centre, Toronto, ON, Canada, 2 Sunnybrook Health Science Centre, Odette Cancer Centre, Toronto, ON, Canada, 3 Sunnybrook Health Sciences Centre-Odette Cancer Centre, Toronto, ON, Canada, 4 Sunnybrook Health Sciences Centre, Toronto, ON, Canada, 5 University of Toronto, Toronto, ON, Canada Purpose/Objective(s): Stereotactic ablative radiation therapy (SABR) is increasingly being used to treat patients with oligometastatic cancer, but there is a paucity of prospective studies. The purpose of this study was to measure toxicities and patients’ quality of life (QOL) after SABR was used to treat patients with up to 5 metastases. Materials/Methods: Patients with  5 metastases confined to the lung, liver, brain, and/or bone, with no more than 3 metastases in any one organ system, were eligible for the study; SABR was delivered according to established institutional protocols. Acute and late toxicities were pro- spectively recorded using Common Terminology Criteria for Adverse Events v 4.0 at baseline, on last day of treatment, 1 week after treatment, every month until 3 months, and then every 3 months for 2 years. Quality of life was assessed using the EORTC QLQ-C30 instrument at the same time intervals. Results: From 2010-2012, 43 patients were enrolled in the study with a median age of 70 (range 43-86). Twenty-three of the patients were female (53.5%), and 20 were male (46.5%); 41 patients completed their treatment, 17 (41.5%) to a single site and 24 (58.5%) to multiple sites. For those who received treatment to multiple sites, 19 (79.2%) had 2 sites treated with SABR, 4 (16.7%) had 3 sites and 1 (4.1%) had 4 sites treated with SABR. There were 6 (16%) patients with grade 2 as their worst toxicity, reporting 12 toxicities in total. No patient had acute grade  3 toxicity. There were 13 patients (46%) with grade 2 as their worst late toxicity, reporting 19 toxicities in total. There were also no grade  3 late toxicities. The impact on patients’ quality of life was variable over time with a more positive impact seen in the short-term. At the 1 week and 1 month time, 4 patients (12.9%) had a meaningful increase in their physical functioning from baseline, while 22 (71%) were stable. In terms of role functioning during the same period, 8 patients (25%) had a meaningful increase, and 17 (53.1%) were stable. This is in contrast to no patients having a meaningful increase in physical functioning at 6 months and 11 (42.3%) reporting a decrease. A similar trend is seen with role functioning where 3 patients (11.5%) had a meaningful increase at 6 months compared to 9 (34.6%) who decreased; overall global health status was maintained 6 months after treatment with 3 patients (11.5%) reporting an improvement and 12 (46.2%) remaining stable, which is very similar to what was seen at 1 week with 3 (9.4%) patients reporting an improvement and 18(56.3%) remaining stable. Conclusion: The toxicity profile after treating up to 4 sites of metastatic disease with SABR is quite favorable with no grade  3 toxicity recorded in this prospective study. The impact on the patients’ QOL is variable, but global health status is preserved after treatment. Author Disclosure: D. Erler: None. P. Cheung: None. A. Sahgal: None. H.T. Chung: None. I. Poon: None. W. Chu: None. L. Zhang: None. G. Bedard: None. N. Pulenzas: None. E. Chow: None. 3231 Changes and Dosimetric Correlates of Health-Related Quality of Life After Stereotactic Ablative Radiation Therapy for Liver Metastases J. Helou, 1 , 2 I. Thibault, 1,2 D. Earler, 1 W. Chu, 1,2 R. Korol, 1,2 M.T. Davidson, 1,2 L. Zhang, 1 K. Chan, 1 E. Chow, 1,2 and H.T. Chung 1,2 ; Poster Viewing Abstracts 3229; Table 1 RT group (%) Non-RT group (%) P-value Stricture 4.8 0.0 NS Flare 2.4 4.5 NS Fistula 2.4 9.0 NS IBD Med Escalation 0.0 4.5 NS International Journal of Radiation Oncology  Biology  Physics E492