Electronic Poster The VIP Cancer MR Session Exhibition Hall Monday, May 9, 2016: 10:45 - 11:45 2635 Longitudinal Diတusion MRI for Treatment Response Assessment: Preliminary Experience using an MRI-Guided tri-Cobalt 60 Computer #1 Radiotherapy System Yingli Yang1, Minsong Cao1, Ke Sheng1, Yu Gao2, Allen M Chen1, Mitchell Kamrava1, Percy Lee1, Nzhde Agazaryan1, James Lamb1, David H Thomas1, Daniel A Low1, and Peng Hu2 1Radiation Oncology, University of California, Los Angeles, Los Angeles, CA, United States, 2Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, United States Diတusion weighted MRI is promising for early prediction of response to radiotherapy 1, 2, and for adaptive radiotherapy, wherein the treatment plan is adapted during treatment based on patients’ response assessed by imaging. Currently DWI-based adaptive radiotherapy is not widely adopted because of scientiတāc and practical challenges. Most importantly, the timing for DWI imaging is not well studied without longitudinal diတusion MRI data at a တāner time interval (every 2-5 days) throughout the course of treatment. A recently commercialized MRI-guided radiotherapy system (ViewRay) may eliminate the current challenges and bring diတusion MRI- guided adaptive radiation therapy closer to clinical utility. 2636 MR T1ρ imaging study on normal-appearing brain in patients with nasopharyngeal carcinoma after radiotherapy Computer #2 Xiang Xiao1, Yikai Xu1, Yuankui Wu1, Yingjie Mei2, and Queenie Chan3 1Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, China, People's Republic of, 2Philips Healthcare, Guangzhou, China, People's Republic of, 3Philips Healthcare, HongKong, China, People's Republic of Radiation induced encephalopathy is one of the most serious complications of radiotherapy (RT) for treatment of nasopharyngeal carcinoma (NPC). In order to detect early radiation-induced changes in gray matter (GM) and white matter (WM) of NPC patients after RT, we recruited NPC patients before RT and after RT with normal-appearing brain for MR T1ρ examination. We found abnormal microstructure changes of WM had already happened in NPC patients after RT even when routine MRI တāndings are negative. MR T1ρ imaging can be used to detect early radiation-induced changes of WM following RT for NPC patients. 2637 Targeted MRI contrast guided drug delivery: Magnevist and doxorubicin encapsulated into liposomes for detection and treatment of Computer #3 glioma Xiaoli Liu1, A. B. Madhankumar2, Patti A. Miller1, Becky Webb2, James R. Connor2, and Qing X. Yang1 1Radiology, College of Medicine Penn State University, Hershey, PA, United States, 2Neurosurgery, College of Medicine Penn State University, Hershey, PA, United States Glioma in its early stage is hard to detect and treat because MRI contrast agent and chemotoxin are not able to cross the blood brain barrier (BBB). The conventional MRI contrast agent such as Magnevist (GD-DTPA) is limited to the cases where the BBB is signiတācantly compromised by the tumor. Present study reports the development of a novel theranostic tool, interleukin-13-liposomes-Magnevist- doxorubicine (IL-13-lip-magnevist-dox) for detection and treatment of glioma. Our results demonstrated that IL-13-lip-magnevist-dox own the potential to speciတācally target, concomitantly detect and treat glioma in its early stage when BBB is still intact. 2638 Early Prediction and Evaluation of Breast Cancer Response to Neoadjuvant Chemotherapy Using Quantitative DCE-MRI Computer #4 Alina Tudorica1, Karen Y Oh1, Stephen Y-C Chui1, Nicole Roy1, Megan L Troxell1, Arpana Naik1, Kathleen Kemmer1, Yiyi Chen1, Megan L Holtorf1, Aneela Afzal1, Charles S Springer, Jr1, Xin Li 1, and Wei Huang1 1Oregon Health & Science University, Portland, OR, United States DCE-MRI was performed in 28 breast cancer patients (29 tumors) before, during, and after neoadjuvant chemotherapy (NACT). Several DCE-MRI pharmacokinetic (PK) parameters were found to be good early predictors of pathologic complete response (pCR) vs. non-pCR after only one NACT cycle. In addition, several PK parameters and tumor size were signiတācantly correlated with pathologically measured residual cancer burden (RCB). 2639 The USPIO GEH121333 as a dual R1 and R2 Contrast Agent for Imaging Response to Anti-angiogenic Therapy Computer #5 Jana Cebulla1, Eugene Kim1, Dan E Meyer2, Karina Langseth3, Tone F Bathen1, Siver A Moestue1, and Else Marie Huuse1,4 1Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway, 2Diagnostics, Imaging and Biomedical Technologies, Niskayuna, NY, United States, 3GE Healthcare AS, Oslo, Norway, 4Department of Medical Imaging, St. Olavs University Hospital, Trondheim, Norway Preclinical-phase iron oxide particles (GEH121333), with a high r1 /r 2 ratio compared to other iron oxide nanoparticles, were used for monitoring vascular response to bevacizumab treatment in ovarian cancer xenografts. Susceptibility contrast MRI using T2 and T 2 * mapping revealed a treatment induced decrease in blood volume and vessel density, but not in vessel size. Additionally, DCE-MRI using gadodiamide detected a decrease in perfusion and/or permeability. In combination, these two methods provide a comprehensive assessment of anti-angiogenic treatment eတects. Lastly, GEH121333 particles induced a strong signal increase in T1 w images, which shows promise for its use also as a positive contrast agent. 2640 Assessment of anti-angiogenic e†ȁcacy of targeted ECO/siHIF-1α nanoparticles with DCE-MRI and a biodegradable macromolecular Computer #6 contrast agent Anthony Malamas1 and Zheng-Rong Lu1 1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States To apply DCE-MRI with a biodegradable macromolecular contrast agent in assessment of the e†ȁcacy of targeted ECO/siRNA nanoparticles for silencing HIF-1α expression for cancer therapy in a mouse colon cancer model. DCE-MRI non-invasively revealed that the treatment resulted in over 70% reduction in average tumor blood တāow (Fp), permeability-surface area product (PS), and plasma volume fraction (Vp) in the treatment group as compared to the saline control group (p < 0.05). The treatment was eတective to inhibit tumor angiogenesis and proliferation. 2641 Inhibiting 2-hydroxyglutarate production reverses some, but not all, of the MRS-detectable metabolic markers of mutant IDH1 in glioma Computer #7 Pavithra Viswanath1, Russell Pieper2, and Sabrina M Ronen1 1Radiology, University of California San Francisco, San Francisco, CA, United States, 2Neurological Surgery, University of California San Francisco, San Francisco, CA, United States Mutations in IDH1 are predominant in low-grade gliomas, and inhibitors of the mutant IDH1 enzyme are under investigation as therapeutic agents. Beyond 2-HG production, the IDH1 mutation also induces a broader pattern of 1H-MRS-detectable metabolic alterations. In this study, we investigated whether inhibiting mutant IDH1 using AGI-5198 reverses the metabolic reprogramming observed in IDH1 mutant glioma cells. Our results indicate that AGI-5198 treatment, while completely inhibiting 2-HG production, nevertheless only partially reverses other metabolic alterations and results in a moderate eတect on clonogenicity of IDH1 mutant cells. 2642 Assessment of R1 Relaxation Rate Error in DCE-MRI Using Bookend Measurements Computer #8 Michael Josef Dubec1 and Lucy Elizabeth Kershaw1,2 1CMPE, The Christie NHS Foundation Trust, Manchester, United Kingdom, 2Institute of Cancer Sciences, University Of Manchester, Manchester, United Kingdom Dynamic contrast enhanced MRI (DCE-MRI) allows quantitative assessment of tumour status. The addition of a relaxation rate (R1 ) measurement following the dynamic acquisition in DCE-MRI studies allows the uncertainty in the conversion from signal intensity (S) to R1 to be assessed. In this work the eတect of errors in တāip angle and pre-contrast signal estimation on the S(t) to1 R (t) conversion were evaluated. Results indicated that uncertainty in the measurement of Spre had greater eတect than realistic တāip angle variations on the S(t) to R1 (t) conversion, and that the error was tissue dependent. 2643 Spatial Overlapping between the Subvolumes with Elevated CBV and with Hypercellularity in Glioblastoma Computer #9 Hemant Parmar1, Daniel Wahl2, Priyanka Pramanik2, Michelle Kim2, Theodore S Lawrence2, and Yue Cao1,2 1Radiology, University of Michigan, Ann Arbor, MI, United States, 2Radiation Oncology, University of Michigan, Ann Arbor, MI, United States Standard imaging for glioblastoma relies on post-contrast T1 and T2 FLAIR MRI sequences, which do not accurately reတāect tumor biology. Advanced MRI techniques can deတāne biologically relevant and prognostic features of glioblastoma including perfusion-based volumes with high cerebral blood volume (VhCBV ) and high b-value diတusion-based hypercellular subvolume (HCV). We deတānedhCBV V and HCV in 24 patients with glioblastoma prior to undergoing chemoradiation. Surprisingly, there was little overlap between VhCBV and HCV within individual patients, which suggests that these volumes represent distinct aspects of tumor biology and may be independently prognostic. Analysis of failure patterns and prognostic relevance is ongoing. 2644 Ultrahigh-တāeld (9.4T and 17.6T) magnetic resonance imaging of retinoblastoma: ex vivo evaluation of microstructural anatomy and Computer #10 disease extent Marcus Christiaan de Jong1, Pim de Graaf1,