Purpose/Objective(s) Oligometastatic (≤5 lesions) lung cancers or synchronous primary lung tumors with associated co‐morbidities may not retain their treatment position during SBRT treatments when using multiple isocenters due to longer treatment times, back pain, or shortness of breath. Lung SBRT using SIMT VMAT plans with flattening filter free (FFF) beam can reduce treatment time, improve patient comfort, and improve clinic efficiency. Herein we present our clinical results for treating multiple primary or oligometastatic lung cancers using SIMT lung SBRT. Materials/Methods Sixty-two patients with synchronous primary lung cancers or oligometastatic lung lesions (two, n = 51; three, n = 6; four, n = 3; five n = 2; total tumors = 142) were simulated with 4D-CT based MIP images and/or abdominal compression and treated with highly conformal SIMT SBRT plans using co/non-coplanar VMAT geometry. Common prescriptions were 50-55 Gy in 5 fractions (50 pts), and 54 Gy in 3 fractions (12 pts), prescribed to each PTV margin with the 70-80% isodose line. Advanced Acuros-XB dose engine for 6FFF beam was used for tissue heterogeneity corrections. NRG RTOG-0618/0813 protocols criteria were used for plan quality evaluation and dose constraints to organs-at-risk (OAR). CBCT-guided SIMT treatment was delivered every other day with 6DOF PerfectPitch couch corrections, and overall treatment time was within 15 minutes. Reported outcomes includes tumor local control (LC) rates and toxicities profiles using CTCAE v5 guidelines. Results All SIMT lung SBRT plans met RTOG-0618/0813 requirements for target coverage and dose to OAR. Average PTV volume was 16.2 cc (range, 2.17–167.8 cc). Mean follow up after last fraction dose was 20 months (range 0–67.2 months). Of the 62 patients treated, 54 had an adequate post-treatment chest CT scan to assess LC. Among patients with treated and followed up tumors, LC was achieved in 51/54 (94.4%), and for toxicities, 33/54 (61%) of patients developed CTCAE grade 1 asymptomatic pneumonitis on chest CT in on average, 6.2 months after SIMT lung SBRT. No symptomatic pneumonitis, esophagitis, or rib fracture occurred. CTCAE grade 2 chest wall pain occurred in 1 patient with pre-existing neuropathic rib pain which was managed with gabapentin. Thirty-six patients had distant metastasis and 22 patients died from distant failure or a competing comorbidity. Conclusion Highly conformal SIMT lung SBRT for synchronous primary or oligometastatic lung cancers was safe, fast, and an effective treatment option demonstrating excellent tumor LC rates (>94%) with low treatment related toxicity. SIMT improved patients’ compliance and comfort for those who may not tolerate traditional extended treatment course/time and reduces isocenter shifts with repeated CBCT imaging for patient set up and verification. SIMT improves clinic workflow and potentially reduced intra-fractional set up errors. Kaplan-Meier estimate with longer clinical follow up in a larger patient cohort of SIMT lung SBRT is warranted.

SIML HyperArc Brain SRT for multiple brain metastases has excellent local control and low toxicity profile in our patients. It can significantly reduce treatment delivery time as compared to traditional multiple-isocenter brain SRT or chronologically separate treatment courses and thus, help to improve patient comfort, compliance, ease of care, and clinic workflow. Longer median follow up of SIML brain SRT on larger patient cohort is warranted.

e20638 Background: Patients with stage I (T1/T2a, N0) SCLC have a 5-year survival of 48% after surgical resection. Unfortunately, 70% of limited stage patients are inoperable and thus reliant on definitive radiation. The use of SBRT has increased 16-fold from 2004-2013 with continued widespread acceptance due to its safety and projected efficacy; however, there is no category one evidence to support this practice. Currently NCCN guidelines cite experience of SBRT in 117 patients from two studies. The impact of SBRT versus EBRT with or without chemotherapy is not yet well defined and requires more evidence to influence treatment decisions. Methods: We used National Cancer Database (NCDB) to identify 4,012 patients with clinical stage I SCLC treated with surgery, or EBRT with chemotherapy, or SBRT with or without chemotherapy from 2011 to 2020. The primary outcome analyzed was overall survival (OS). Secondary analyses evaluated differences amongst age, gender, race, institution, and Charlson Comorbidity Index (CCI). Kaplan-Meier (KM) plots were used to examine survival outcomes and descriptive analysis was performed to examine the characteristics of clinical variables by the different treatment modalities. Cox regression analysis was used to identify factors associated with OS. Results: The utilization of surgery and SBRT in stage I SCLC has increased over the last fifteen years. As of 2020, SBRT volume has increased 657-fold and is combined with chemotherapy in more than 50% of cases. From 2010-2019, those who were treated with surgery-based therapy had a survival advantage (HR 0.64 95%CI 0.58-0.71, p < 0.01) compared to multimodality radiotherapy techniques. For those treated with definitive radiation, there was no significant difference between EBRT with chemotherapy and SBRT with or without chemotherapy (HR 1.11 95%CI 0.97-1.28, p = 0.135). Patients treated with SBRT alone experienced a significantly shorter median OS of 20.4 months compared to those who received SBRT with chemotherapy (median OS 34.3 months, HR 1.74 95%CI 1.38-2.20, p < 0.01). Multivariate analysis revealed better OS for patients under the age of 64 (HR 0.51 95%CI 0.44-0.58, p <0.01) and those with lower CCI (CCI 0, HR 0.82 95%CI 0.70-0.90, p< 0.01); worse OS for males (HR 1.26 95%CI 1.16-1.37, p < 0.01); and no difference between academic or non-academic institutions (HR 0.92 95%CI 0.84-1.01, p= 0.094), white versus black (HR 0.84 95%CI 0.71-1.00, p = 0.054) or non-white patients (HR 1.06 95%CI 0.75-1.50, p = 0.736). Conclusions: Our preliminary results suggest surgery-based multimodality therapy is associated with a higher survival for medically operable patients. There was no survival advantage of EBRT with chemotherapy compared to SBRT especially when chemotherapy is given. Further statistical analysis is underway to confirm these trends and survival differences.

SIML lung SBRT for synchronous primary lung cancers or multiple lung metastases can be used as a variant to traditional multiple isocenter SBRT or chronologically separate treatment courses, and has excellent local control rates and low toxicity profile in our patient population. It can help improve comfort and compliance of the patients who have difficulty lying still for an extended treatment course, and significantly reduces treatment time via isocenter shifts/repeated CBCTs for image guidance, thus improving clinic efficiency.

Purpose/Objective(s) Due to large, irregular and superficial spread of the complex target, conventional radiotherapy via photon and electron beams matching technique for angiosarcoma of total scalp irradiation (TSI) presents major technical and dosimetric challenges. To increase superficial target coverage, reduce normal brain dose, and eliminate the difficulty of patient set up and fields matching, we propose two novel irradiation methods: fully-automated non-coplanar HyperArc VMAT and co-planar Halcyon delivery platform utilizing a 3D-printed 1 cm scalp bolus. Materials/Methods The technical and dosimetric performance of the proposed two novel methods was simulated using nine previously treated TSI patients in our institution. HyperArc plans utilized 6MV-FFF beam (800 MU/min) on SBRT-dedicated Linac with fully-automated HyperArc module and 1 cm 3D-printed scalp bolus for dose build up to the superficial target to deliver a prescription dose of 70 Gy in 35 fractions. For comparison, these plans were re-planned via 4 full-arcs on recently installed fast rotating co-planar Halcyon Linac equipped with 6MV-FFF (800 MU/min) with lower mean energy of 1.3 MeV and nominal depth of maximum dose at 1.3 cm. Identical isocenter location and similar planning parameters and objectives, were used on both Linac platforms. Plan quality, including BED10 and treatment delivery accuracy and efficacy, was compared. Results Both platforms generated highly conformal, homogenous TSI plans and showed statistically insignificant differences on target coverage, mean target dose, conformity, and dose homogeneity. The average BED10 of the mean target dose was 92.0 ± 1.4 Gy (HyperArc) vs 93.4 ± 0.9 Gy (Halcyon) (p = 0.06). HyperArc provided mean brain dose and V60Gy of 8.1 ± 1.5 Gy and 0.8 ± 0.9 cc respectively, compared to 8.5 ± 1.4 Gy (p > 0.05) and 1.4 ± 0.7 cc (p = 0.04), on Halcyon. For both platforms, significantly lower maximal dose of < 5 Gy was observed in organs at risk (OARs), including spinal cord, brainstem, optic pathway, hippocampi, eyes and lenses, and cochlea (p > 0.05 for all OARs). Halcyon plan complexity slightly decreased as seen in the average decreases of total monitor units, modulation factor and beam-on time by 119, 0.6, and 0.6 min respectively, and the estimated overall treatment time was reduced by an average of 2.4 min. Treatment time for both platforms was less than 15 minutes. Portal dosimetry quality assurance results of HyperArc and the corresponding Halcyon plans were 99.8% and 100%, demonstrating comparable treatment delivery accuracy. Conclusion We demonstrated that both Halcyon and HyperArc platforms can deliver an accurate and efficient treatment of greater than 90 Gy BED10 to large, complex and superficial angiosarcoma of the scalp and face with significantly lower mean brain dose of less than 10 Gy. Clinical use of these platforms is underway in our center and highly recommended to other centers, including community centers, expanding the use of Halcyon Linac to underserved patient cohort.

Purpose/Objective(s) Cone-beam CT (CBCT) based organs-at-risk (OARs) delineation is the prerequisite of online adaptive therapy (ART) which can be time-consuming and inefficient. Auto-segmentation on CBCT would reduce the extra clinical resources required, however, it is labor-intensive to retrain the deep-learning auto-segmentation (DLAS) with CBCT contours that need to be labeled. Over standard CBCT, iterative CBCT (iCBCT) yields higher quality images with reduced noise and artifacts. This study aimed to comprehensively evaluate the feasibility of DLAS software trained with planning CT for iCBCT based online adaptive prostate treatment. Materials/Methods Total 25 male pelvis iCBCTs from corresponding prostate patients were selected for this study. An automated treatment planning process was established to simulate the online ART procedure by combining CT-based commercial DLAS software (i.e., trained with planning CT) and knowledge-based treatment planning used to eliminate human bias. Prostate and surrounding critical structures (i.e., bladder, rectum, and femoral heads) were delineated on iCBCT by a CT-based DLAS and by manual modification from corresponding planning CT registration. The geometrics metrics of OARs were computed between DLAS contours and manual contours. The prostate, considered as the gross tumor volume (GTV), was manually modified from DLAS to pursue accurate target dose coverage. For each iCBCT, two VMAT plans of 70 Gy with two full arcs were generated using the manual contour sets and DLAS contour sets respectively, which share the same modified prostate contour. Both plans were normalized to 100% of the prescription dose to cover 98% of the planning target volume (PTV) derived from GTV. The dose distributions from two plans were evaluated on the manual structure sets. The clinical appropriateness was evaluated by assessing D15(Gy), D25 (Gy), D35(Gy), and D50 (Gy) of critical structures following the RTOG-0815. The time required for the automated treatment planning process was recorded. Results Average dice agreement for bladder, rectum, femoral head_L and femoral head_R were 0.87 ± 0.10, 0.82 ± 0.08, 0.91 ± 0.12, and 0.93 ±0.07 respectively. DLAS generated a statistically significant of 0.39 Gy greater on bladder D25 than its counterpart. No statistically significant differences were found in other OARs dosimetric metrics. All unmodified OARs satisfied the dose constraints of RTOG-0815 even with some artifact cases involved. The average time needed for the automated treatment planning process simulating ART was 11.85 minutes including DLAS generated time (0.69 minutes), GTV modified time (0.9 minutes), and plan generated time on CPU (10.26 minutes). Conclusion The proposed DLAS trained with planning CT is a promising contouring solution for iCBCT-based intact prostate online ART in the clinic with labor shortage. Without modification needed, it can generate clinically acceptable OARs segmentation on iCBCT images within a limited time.

Purpose/Objective(s) To demonstrate the clinical feasibility of a novel inverse planning algorithm via dose optimizer (DO) on a treatment planning system (TPS)for generating high-quality treatment plans with significantly faster planning times for Stereotactic Radiosurgery (SRS) of the complex and difficult cases of arteriovenous malformation (AVM) and pituitary adenomas. Materials/Methods After completing the in-house end-to-end phantom testing and independent dose verification of recently upgraded DO on TPS using one institution's IROC anthropomorphic SRS head phantom irradiation credentialing, twenty previously treated SRS patients (10 AVM, average volume 3.61 cc) and (10 pituitary adenomas, average volume 0.86 cc) who underwent manual forward planning on TPS were retrospectively re-planned via DO under IRB protocol. DO finds the target curvature boundary by well formulated linear programming objectives, and inversely optimize SRS plan by isocenter placement, optimization, and sequencing. For identical tumor dose, the DO and original manual plans were compared for target conformity, gradient index, dose to critical organs, and surrounding normal brain. Additionally, various treatment delivery parameters including beam on time were recorded. Results For both patient cohorts, DO provided similar target coverage with better dose conformity, tighter radiosurgical dose distribution with lower value of gradient indices (all p < 0.001), and lower dose to critical organs. For AVM, significant reduction of normal brain V10, V12 and V14 by 4.74 cc, 3.67 cc, and 2.67 cc (all p < 0.001), on average via DO was observed at the cost of as many as twice the numbers of shots (p < 0.001), and relatively longer beam on time (p = 0.012) by a factor of 1.44, compared to the clinical manual plans. For pituitary adenoma, DO provided systematically lower values of V10, V12 and V14 by 1.08 cc, 0.86 cc and 0.68 cc (all p < 0.001), on average and lower maximal dose to optic pathway by 0.7 Gy (p = 0.005), but had almost twice the numbers of shots (p < 0.001) and increased beam on time (p = 0.005) by a factor of 1.2, compared to the original manual plans. However, for both patient groups, average planning time for the DO was < 5 minutes, compared to estimated 30-60 min of manual planning times. Conclusion SRS treatment via new inverse DO provided highly conformal target coverage, steep dose gradient, spared critical organs, and significantly reduced normal brain dose for complex targets who presented with very irregular nidus or pituitary adenoma. DO generated high quality treatment plans and could yield significant time saving in planning the treatment, particularly for inexperienced SRS users–improving patient compliance, and clinic workflow. If available, DO algorithm is suggested for validation and clinical use for irregular, complex and difficult SRS cases in the future.

The DLSEG model for prostate contouring tested demonstrates similar performance in terms of accuracy compared with expert ROs.

L. Downes: None. D. Pokhrel: None. L. Critchfield: None. M.E. Bernard: None. M.E. Randall: None. R.C. McGarry: None.

The 3D MLC-based forward planned GRID therapy enhanced target dose for bulky masses including deep-seated large tumors while protecting skin and adjacent critical organs. This same day MLC-GRID treatment provides safe, effective, and convenient treatment by eliminating the risk to therapists and patient of heavy gantry-mounted physical GRID-block. This rapid 3D MLC-GRID planning and treatment can be easily adopted by any radiation clinics on the same day eliminating the need of longer plan optimization and patient-specific quality assurance. MLC-GRID provides all the dosimetry information in the planning system and potentially allow escalating dose to the bulky masses. It may allow for debulking of unresectable large tumors-opening an avenue for a neoadjuvant treatment option. Clinical follow up of these patients is ongoing.

Transfer learning is a promising approach to incorporate the existing segmentation on prior CT to improve the segmentation accuracy in the adaptive or re-treatment settings.

The investigated auto-segmentation model for prostate anatomy provides compatible performance to manually delineated contours by a Radiation Oncologist.

To present a novel and clinically useful 3D MLC-based forward planning technique for GRID therapy that provides fast, safe, and effective treatment delivery of larger ablative doses to deep-seated bulky tumors. Seven patients (3 head and neck, 1 chest, 1 breast, 1 para-spinal, 1 pelvis) with 7.0 to 12.0 cm diameter tumor sizes were treated using our novel MLC-based 3D-GRID therapy in our clinic. Standard Millenium120 MLC leaves were fitted to gross tumor volume (GTV) to generate 1 cm diameter holes and 2 cm center-to-center distance (at isocenter) mimicking traditional GRID-block pattern using an in-house algorithm. For a single-dose of 15 Gy, 3D MLC-based GRID plans were generated using 6-coplanar gantry positions at 60o spacing (210 o to 150 o) with 90o collimator rotation for a differentially-weighted 6–18MV beams. This MLC fitting algorithm in treatment planning system generates brachytherapy-like dose tunneling distributions without post-processing GTV-contour. Advanced Acuros-based dose was calculated. Dosimetric parameters evaluated include: GTVD50%, GTVD10% (hottest 10% of the GTV), GTV dose heterogeneities (peak-to-valley dose ratio, PVDR), skin dose, dose to immediately adjacent critical structures, and maximal dose 2 cm away from the GTV (D2cm). Additionally, planning time and delivery efficiency was recorded. All 3D-MLC GRID plans exhibited excellent target dose with mean GTVD50%, GTVD10% of 15 Gy being 7.5 ± 0.4 Gy (range: 7.4–8.3 Gy) and 12.4 ± 0.4 Gy (range: 11.2–12.9 Gy) or higher, respectively. Average PVDR and D2cm was 2.9 ± 0.5 (range: 2.5–3.8) and 64 ± 11% (range: 53–78%), respectively. Maximal and dose to 5 cc of skin were 10.6 ± 3.6 Gy (range: 5.5–13.1 Gy) and 6.5 ± 3.2 Gy (range: 2.6–10.5 Gy), on average, respectively. Immediately adjacent critical organs were spared: spinal cord (< 5.2 Gy), heart (< 5.7 Gy), femoral head (< 6.7 Gy) and small bowel (< 4.5 Gy). Average total monitor units and beam-on time was 1975 ± 93 and 3.3 ± 0.2 min, respectively. Overall treatment planning time was about an hour. This novel and clinically useful 3D MLC-based forward planning approach for GRID-therapy resulted in enhanced target dose for deep-seated bulky tumors, low skin toxicity and low doses to adjacent critical organs. This simple and fast MLC-based GRID therapy can be easily adopted by any radiotherapy clinic. It provides detailed dosimetry information and a safe and effective treatment option by eliminating physically heavy traditional single-field GRID-block and could provide same day treatment (by eliminating days of IMRT or Tomotherapy plan optimization and patient-specific quality assurance time) for debunking unresectable large tumors. It also allows for a greater chance for ablative doses for large tumors to provide optimal palliation and optimize local control with immunotherapy. Clinical follow up of these patients is underway and prospective clinical trial with escalated tumor-dose to bulky tumors is highly anticipated.

Radiation pneumonitis (RP) is a dose-limiting toxicity associated with radiotherapy in the treatment of non-small cell lung cancer (NSCLC). Several studies have linked diabetes as a risk factor for development of radiation-induced lung injury and statin medications as a protective parameter. We aimed to further investigate these findings and explore other metabolic risk factors for the development of RP. After IRB approval, we retrospectively evaluated 162 patients with stage III NSCLC treated with definitive chemoradiation at our institution between 2001 and 2014. Chemotherapy was delivered as couplet therapy with the majority of patients receiving carboplatin-paclitaxel (141/162, 87.2%). Patient information including age, gender, comorbidities, medications, serum glucose values, toxicities, disease, and treatment parameters were collected from patients' medical records. Serum glucose values spanning from 90 days prior to 90 days post-radiation therapy (n=2870) were collected. We then categorized values into pre-, during, and post-radiotherapy; defined as within 90 days prior to, during, and within 90 days post-radiotherapy. Patients were then stratified into groups achieving serum glucose values ≥150, ≥175, and ≥200 mg/dL at each of the preceding time points. Chi-Squared analyses were used to analyze the effect categorical variables had on the development of RP in our study population. Parameters achieving significance were selected for analysis against pulmonary toxicity grade. We further used a binary logistic regression model to assess how continuous variables may affect the development of RP. The median prescribed dose was 72 Gy (range= 54-84). The overall rate of RP was 17.9% (n=29). In our dataset, 3/46 (6.5%) diabetic patients developed RP vs. 22/101 (21.8%) patients without diabetes (p=0.022). The rate of radiation-induced lung injury in insulin users was 3/42 (7.1%) vs. 22/105 (21.0%) in non-users (p=0.044). Both diabetes (2.2% vs. 14.9%, p=0.022) and insulin (2.4% vs. 14.3%, p=0.036) were associated with lower incidence of RP requiring medical intervention (grade ³2). Diabetes was further correlated with reduced incidence of grade ³3 RP (0% vs. 9.1%, p=0.037). Serum glucose values at the aforementioned time points were not associated with RP. Neither statins nor other diabetic medications correlated with RP risk. Gross tumor volume (GTV), planning target volume (PTV), radiation technique, radiation dose, dose per fraction, and treatment duration were not significant predictors of our primary endpoints. Finally, patients who developed RP had similar rates of mortality, loco-regional recurrence, and distant metastasis to those without. In contrast to prior data, we identify both diabetes and insulin therapy as protective factors against the development of RP in the treatment of NSCLC. These results should be confirmed by subsequent high-quality prospective studies.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with a notoriously poor prognosis and limited treatment options. Stereotactic body radiation therapy (SBRT) has emerged as a potential treatment modality for local tumor control of unresectable pancreatic adenocarcinoma. We aimed to evaluate the safety, efficacy, and feasibility of SBRT in unresected pancreatic cancer patients while also identifying prognostic factors. After institutional review board approval, we retrospectively reviewed patients treated with SBRT for unresectable/medically inoperable PDAC at our institution from 2004 to 2014. Our primary study endpoints included overall survival (OS) and local-progression-free survival (LPFS). Secondary endpoints included distant-progression-free-survival (DPFS), regional-progression-free-survival (RPFS), and radiation toxicity. Study endpoints were analyzed with the Kaplan-Meier method. Follow-up was calculated using the Kaplan-Meier method. Cox proportional hazard models were utilized to study the association between survival endpoints and risk factors. Logistic regression was used to assess clinical and dosimetric risk factors for grade 3+ toxicity. We identified 155 patients treated for PDAC at our institution with a median age of diagnosis of 72.2 (range, 36.7-90.3). SBRT was delivered either as a single (32.3%) or multifraction (67.7%) regimen with a median dose of 36 Gy (range, 24-36). There were 12 patients (7.7%) with stage IV disease at diagnosis and 16 that received prior radiation (10.3%). The majority of patients (71.0%) received chemotherapy, with the predominate regimen being gemcitabine based (72.8%). With a median follow-up time from SBRT of 7.4 months (95% CI, 6.7-8.1) the Kaplan-Meier estimates from treatment to 1-year post-SBRT were as follows: OS 31.6%; LPFS 63.0%; RPFS 86.8%; DPFS 54.4%. On multivariate analysis (MVA), pre-SBRT CA 19-9 [p=0.025, HR 1.0002 (95% CI, 1.00003-1.0004)] and prior irradiation [p<0.001, HR 14.038 (95% CI 3.186-61.857)] were significantly associated with OS. On MVA for OS from SBRT we identified prior radiation [p<0.001, HR 53.909 (95% CI 6.210-467.975)] and PTV [p=0.038, HR 1.047 (95% CI 0.038)] as risk factors. Pre-SBRT CA 19-9 and post-SBRT CA 19-9 were also identified as risk factors for distant metastases and local failure on MVA, respectively. At 1-month post-SBRT the rate of grade 3+ was 14.7%. Toxicities were predominantly GI related; including enteritis, duodenal stricture, and gastric outlet obstruction. Of these, enteritis was the most common (n=3). On logistic regression only pre-SBRT CA 19-9 [p=0.045, OR 1.0004 (95% CI 1.000-1.001)] was associated with increased incidence of grade 3+ toxicity. This review demonstrates that SBRT is safe and feasible for unresected pancreatic cancer. We identify pre-SBRT CA 19-9 and prior radiation as predictive of overall survival. Finally, we show low toxicities associated with SBRT in this cohort.

Introduction: A growing body of preclinical data suggests that statins may exert potent antitumor effects, yet the interactions of these medications with standard therapies and clinical outcomes in this population is less clear. We assessed the impact of statin use on outcomes in patients with advanced-stage pancreatic adenocarcinoma undergoing various treatments. Materials and Methods: After institutional review board approval, we conducted a retrospective-cohort study consisting of 303 newly diagnosed advanced-stage pancreatic adenocarcinoma patients to determine the impact of statin use on outcomes. Univariate and multivariable Cox proportional hazard regression models were utilized to estimate hazard ratios (HRs). Time-to-event was estimated using Kaplan-Meier survival analysis for overall survival, distant metastasis, and locoregional failure. Baseline and active statin usage were assessed and to mitigate risk of immortal time bias, subanalysis excluding patients with under 6 months of follow-up was conducted. Results: Both prior (P=0.021) and active (P=0.030) statin usage correlated with improved survival in this cohort. Surgery, chemoradiation, and statin use improved 2-year survival rates (84.1% vs. 55.0%; P<0.001). On multivariable analysis, statin exposure was associated with overall survival (HR, 0.662; P=0.027) and trended to significance for freedom from distant metastasis (HR, 0.577; P=0.060). Comorbid conditions were not significantly associated with outcomes. Conclusions: Statin use was associated with improved overall survival in advanced-stage pancreatic adenocarcinoma patients. This data supports previous findings in early-stage pancreatic adenocarcinoma and other cancer sites. To our knowledge this is the first report to examine the efficacy of statin use as a supplementary treatment option in advanced-stage pancreatic adenocarcinoma patients.