Elita DeFeo¹, Isabel Dittmann², Yannick Berker², Li Su³, Eugene Mark², David Christiani³, and Leo L. Cheng^4
1Pathology, Massachusetts General Hospital, Charlestown, MA, United States, ²Pathology, Massachusetts General Hospital, ³Environmental Health, Harvard School of Public Health, ⁴Radiology, Pathology, Massachusetts General Hospital

Despite lung cancer being the primary cause of cancer related death in both men and women in the United States, there is no early screening tool available to the general public. Due to the high costs and the radiation exposure of CT or PET, these technologies are not feasible as screening tools. Clinicians desperately need a new diagnostic tool to provide biochemical information that is essential for making early diagnoses and subsequent treatment decisions. In this study we are assessing the matched tissue and sera metabolomic profiles of lung cancer patients in hopes of discovering serum lung cancer metabolomic profiles that can provide patient triages for further tests.

Rob H Ireland^1,2, James A Swinscoe², Matthew Q Hatton², Helen Marshall¹, Salma Ajraoui¹, Juan Parra-Robles¹, and Jim M Wild^1
1Academic Radiology, University of Sheffield, Sheffield, S. Yorkshire, United Kingdom, ²Academic Clinical Oncology, University of Sheffield, Sheffield, S. Yorkshire, United Kingdom

This work demonstrates the feasibility of acquiring synchronous helium-3 lung ventilation and proton MRI in a single breath-hold imaging sequence for NSCLC patients. The availability of the concurrent proton MRI enables an automatic mutual information image registration of the helium-3 MRI to a lung CT. Such images could be valuable in the planning and evaluation of lung disease treatment.

Hatsuho Mamata^1,2, Junichi Tokuda^1,2, Ritu R Gill^1,2, Robert F Padera^2,3, Robert E Lenkinski^2,4, David J Sugarbaker^2,5, and Hiroto Hatabu^1,2
1Radiology, Brigham and Women's Hospital, Boston, MA, United States, ²Harvard Medical School, Boston, MA, United States, ³Pathology, Brigham and Women's Hospital, Boston, MA, United States, ⁴Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States, ⁵Thoracic surgery, Brigham and Women's Hospital, Boston, MA, United States

DCE-MRI indices and parameters were evaluated, especially focused on clinical application of pharmacokinetic analysis in solitary pulmonary nodules. kep value may be a potential biomarker to distinguish between malignant and benign tumors.

Cheng-Hung Chou¹, Yi-Fang Cheng¹, Amit Kumar¹, Konan Peck¹, and Chen Chang^1
1Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan

Signal peptide-CUB-EGF-like domain containing protein 3 (hSCUBE3) was found to be up-regulated in highly invasive lung cancer cell lines and in patients with poor prognosis; however the functions of hSCUBE3 in lung cancer progression is not clear yet. In this study, steady-state-contrast-enhanced MRI (SSCE-MRI) was used to evaluate the blood vessel structure in xenograft tumors in NOD-SCID mice transplanted with lung adenocarcinomar cells with and without hSCUBE3 knockdown.

Shonit Punwani¹, King Kenneth Cheung¹, Nicholas Skipper¹, Alan Bainbridge², Stuart Taylor¹, Ashley Groves³, Sharon Hain³, Simona Ben-Haim³, Michael Steward³, Ananth Shankar⁴, Stephen Daw⁴, Steve Halligan¹, and Paul Humphries^1
1Centre for Medical Imaging, University College London, London, United Kingdom, ²Department of Medical Physics and Bioengineering, University College London, ³Institute of Nuclear Medicine, University College London, ⁴Paediatrics, University College London Hospital

This study compares the accuracy of Short Tau Inversion Recovery - Half Fourier Single Shot Turbo Spin Echo (STIR-HASTE) MR imaging, STIR-HASTE + Dynamic Contrast Enhanced (DCE) MR, and Positron Emission Tomography / Computed Tomography (PET-CT) for detection of focal splenic lesions in lymphoma.

Thomas Kwee¹, Erik Akkerman², Rob Fijnheer³, Marie Jose Kersten⁴, Joseph Zsiros⁵, Inge Ludwig⁶, Marc Bierings⁷, Jaap Stoker², and Rutger-Jan Nievelstein^1
1Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands, ²Department of Radiology, Academic Medical Center, Amsterdam, Netherlands,³Department of Hematology, Meander Medical Center, Amersfoort, Netherlands, ⁴Department of Hematology, Academic Medical Center, Amsterdam, Netherlands,⁵Department of Pediatric Oncology, Academic Medical Center, Amsterdam, Netherlands, ⁶Department of Hematology, University Medical Center Utrecht, Utrecht, Netherlands, ⁷Department of Pediatric Hematology, University Medical Center Utrecht, Utrecht, Netherlands

Whole-body MRI may be a valuable alternative to (FDG-PET/)CT for staging lymphoma. However, it is unknown whether a whole-body MRI protocol is necessary, or whether an MRI protocol that only has the usual CT coverage (i.e. head/neck and trunk) is comparable while less time-consuming. In this prospective study including 100 consecutive patients with newly diagnosed lymphoma, whole-body MRI did not detect any clinically relevant lesions outside the field of view of an MRI protocol that only includes the head/neck and trunk. Therefore, it may be sufficient to only include the head/neck and trunk when using MRI for staging lymphoma.

Shonit Punwani¹, Paul Humphries¹, Stuart Taylor¹, Stephen Daw², Ananth Shankar², Alan Bainbridge³, Ziauddin Zia Saad⁴, Ashley Groves⁴, and Steve Halligan^5
1Centre for Medical Imaging, University College London, London, United Kingdom, ²Paediatrics, University College London Hospital, ³Department of Medical Physics and Bioengineering, University College London, ⁴Institute of Nuclear Medicine, University College London, ⁵Centre for Medical Imaging, University College London

Chemotherapy effect has been related to initial tumour cellular density and metabolic activity. ADC is correlated with cellular density and PET SUV measurements to metabolic activity. This study investigates the relationship between pretreatment ADC / SUV values treatment response as determined by tumour volume reduction.

Seung-Cheol Lee¹, Harish Poptani¹, Hari Hariharan¹, Sunita Nasta², Jakub Svoboda², Stephen J Schuster², and Jerry D Glickson^1
1Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²Department of Medicine, Hematology Oncology Division, University of Pennsylvania, Philadelphia, PA, United States

1H MRS and MRI methods (Lactate, total choline and ADC) were applied to detect therapeutic response in non-Hodgkin's lymphoma patients. Recently developed Hadamard slice-encoded selective multiple quantum coherence chemical shift imaging sequence was used for localized detection of lactate. PRESS and diffusion-weighted EPI were used for tCho and ADC measurements. Lac and tCho decreased after treatment while ADC increased. A 3T scanner was used.

Wieland H Sommer¹, Steven Sourbron², Maximilian F Reiser¹, Karin A Herrmann¹, and Christoph Zech^1
1Department of Radiology, University Hospital Munich, Grosshadern Campus, Munich, Bavaria, Germany, ²University of Leeds, Leeds, United Kingdom

This study analyzes different perfusion parameters from dynamic-contrast-enhanced MRI of the liver in patients with hypervascularized liver metastases. The perfusion parameters are correlated with specific-uptake-values (SUV)derived from PET-CT which typically serve as the standard of reference for therapy monitoring. Especially the arterial plasma flow shows very high correlations with SUV and may therefore be a valuable tool for MRI-therapy monitoring especially in antiangiogenetic therapies.

Yonggang Lu¹, Jacobus F.A. Jansen², Hilda E. Stambuk¹, Yousef Tehrani-Mazaheri¹, Nancy Lee¹, Jason A. Koutcher¹, and Amita Shukla-Dave^1
1Memorial Sloan-Kettering Cancer Center, New York, NY, United States, ²Maastricht University Medical Center, Maastricht, Netherlands

In the present study, correlation of quantitative parameters derived from IVIM- and DCE- MRI techniques was performed in neck nodal metastases. The results showed that D* (pseudo-diffusion coefficient) is positively correlated to Ktrans (volume transfer constant), vp( blood plasma volume fraction) and ve (extravascular extracellular space volume fraction) are positively correlated to D* and ADC (apparent diffusion coefficient), respectively. These initial results show the feasibility of characterizing diffusion and perfusion parameters using IVIM- and DCE- MRI in neck nodal metastases. In future, these techniques may be useful in assessing early treatment response in head and neck cancer patients.

Rebecca E Thornhill¹, Greg O. Cron¹, Ian Cameron¹, Adnan Sheikh¹, Gina Di Primio¹, Joel Werier¹, Mark E Schweitzer¹, Jing Zhang², and Xiao Guang Cheng^2
1The Ottawa Hospital, Ottawa, Ontario, Canada, ²Beijing Ji Shui Tan Hospital, Beijing, China, People's Republic of

Musculoskeletal tumors comprise a diverse group of uncommon neoplasms. Conventional contrast-enhanced MRI techniques are inadequate for distinguishing malignant from benign masses. Quantitative dynamic contrast-enhanced (DCE-)MRI techniques followed by tracer kinetic modeling may offer improved diagnostic accuracy, but requires descriptors that can capture the spatial extent (‘shape’) and complexity (‘texture’) of tracer kinetic parameters like K^trans. We retrospectively evaluated both textural and shape features extracted from K^trans maps obtained from 86 patients with biopsy confirmed musculoskeletal tumors. This combined analysis achieved a sensitivity, specificity, and accuracy of 75%, 79%, and 77%, respectively for the discrimination of benign from malignant masses.

N. Jane Taylor¹, Ian C Simcock¹, J. James Stirling¹, Aftab Khan², Rob Glynne-Jones², Anwar R Padhani¹, and Vicky J Goh^1
1Paul Strickland Scanner Centre, Mount Vernon Hospital, Northwood, Middlesex HA6 2RN, United Kingdom, ²Cancer Centre, Mount Vernon Hospital, Northwood, Middlesex HA6 2RN, United Kingdom

Assessment of tumour vascularisation and angiogenesis may provide prognostic and predictive information. This may be evaluated in primary colorectal cancer using dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) and dynamic contrast enhanced computed tomography (DCE-CT). Test-retest agreement is highly relevant to clinical utility but has not been compared in the same patient cohort to date. This prospective study was performed to compare the test-retest agreement of DCE-MRI and DCE-CT. Test-retest agreement for both techniques was adequate for clinical practice, and slightly better for DCE-CT than DCE-MRI for blood flow.

Claudia Weidensteiner¹, Mehdi Ordikhani-Seyedlar², Anna Werres³, Nadja Osterberg³, Astrid Weyerbrock³, and Wilfried Reichardt^2
1MR Development and Application Center, University Medical Center Freiburg, Freiburg, Germany, ²Department of Radiology/Medical Physics, University Medical Center Freiburg, Freiburg, Germany, ³Department of Neurosurgery, University Medical Center Freiburg, Freiburg, Germany

The treatment effect of the chemotherapeutic drug temozolomide (TMZ) in combination with the nitric-oxide donor JS-K was investigated with DCE-MRI in rat gliomas in vivo. Nitric-oxide donors can enhance the transport of drugs to brain tumors. The acute effect of JS-K was an increase in permeability of the blood-tumor barrier and/or tumor perfusion. After 1 week of treatment there was a significant decrease in tumor permeability/perfusion and tumor size for TMZ and TMZ+JS-K as compared to control. JS-K alone had no effect. TMZ+JS-K led to an increased edema formation but showed otherwise no difference to TMZ alone.

Natalie J Serkova¹, Erica L Pierce², Kendra M Hasebroock¹, Andrea L Merz¹, Todd M Pitts², and Gail Eckhardt^2
1Anesthesiology, University of Colorado Denver, Aurora, CO, United States, ²Medical Oncology, University of Colorado Denver

The goal of this study was to establish functional (DW-MRI) and metabolic (PET and MRS) imaging end-points for therapy response to classic cytotoxic and novel cytostatic agents. A mouse colorecral cancer model was chosen to evaluate therapy response to a novel IGF1R tyrosine kinase inhibitor (cytostatic) and to irinotecan (cytotoxic). Specific multiparametric imaging end-points for therapeutic responses to a novel cytostatic STI (include ecreased glucose and choline uptake by PET as well as decreased lactate and choline metabolism by MRS). In contrast, cytotoxic effects of a chemotherapeutic agent result in increased ADC by DW-MRI and increased phospholipid and nucleotide breakdown.

Jun Chen¹, Kiaran P McGee¹, Yogesh K Mariappan¹, kevin j Glaser¹, Stephen M Ansell¹, Kay M Pelletier¹, Deanna M Grote¹, and Richard L Ehman^1
1Mayo Clinic, Rochester, MN, United States

In the treatment of cancer with chemotherapy, a key strategy is to identify as early as possible chemotherapy induced tumor response. Traditionally, therapeutic response is derived from imaging based volumetry, requiring a significant time delay from chemotherapy administration to response detection. This work describes the application of magnetic resonance elastography (MRE) based measurement of tumor stiffness to detect early response to chemotherapy. Results indicate that a statistically significant change in MRE-based tumor stiffness can be detected approximately four hours post therapy and suggests that this measure may be a new and highly sensitive biomarker of chemotherapy tumor response.

Mary E Loveless^1,2, Deborah Lawson³, Michael Collins³, Deborah Morosini³, Corinne Reimer³, Dennis Huszar³, Jane Halliday⁴, John C Waterton⁴, John C Gore^2,5, and Thomas E Yankeelov^2,5
1Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, ²Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, ³Cancer Bioscience, AstraZeneca, Boston, MA, United States, ⁴Translational Sciences: Imaging, AstraZeneca, Macclesfield, Cheshire, United Kingdom, ⁵Radiology and Radiological Science, Vanderbilt University, Nashville, TN, United States

AZD1480 is a novel small molecule inhibitor of Jak 1/2, which have been shown to be key mediators of Stat3 activation. Both DW-MRI and DCE-MRI have been widely used previously to monitor cancer treatment. Jak/Stat pathway inhibition has been shown to modulate tumor cell survival and tumor angiogenesis, so this work seeks to assess the utility of DW-MRI and DCE-MRI in assessing the efficacy of AZD1480 compared to the anti-angiogenic drug cediranib at early treatment time points. The results fo this study indicate that DW-MRI is more sensitive to the effects of AZD 1480 treatment compared to DCE-MRI measurements.

Kyung Won Kim¹, Jeong Min Lee¹, Ji Suk Park¹, Yong Sik Jeon¹, Joon Koo Han¹, and Byung Ihn Choi^1
1Radiology, Seoul National University Hospital, Seoul, Korea, Republic of

CKD-516 is a vascular disrupting agent that disrupts the tubulin cytoskeleton of proliferating neo-endothelial cells. This leads to the selective destruction of pre-existing tumor blood vessels. In rabbit VX2 tumor model, the vascular shutdown effect of CKD-516 was evaluated using free-breathing radial DCE-MRI on 3T clinical machine. Our results showed that a single dose of CKD-516 significantly diminished tumor DCE-MRI parameters (K-trans and iAUC) until 36 hours post-treatment. Tumors with high initial Ktrans values, indicative of well-developed pre-existing vasculature, showed greater reduction of DCE-MRI parameters after CDK-516 treatment.

Peter Gibbs¹, Arfan Ahmed¹, Martin Pickles¹, and Lindsay Turnbull^1
1Centre for MR Investigations, University of Hull, Hull, United Kingdom

Textural analysis, based on the spatial grey-level dependence matrix method, has been performed on 100 breast cancer patients prior to treatment with neoadjuvant chemotherapy. Texture parameters were calculated pre-contrast administration and 1, 2, 3, 4 and 5 minutes post-contrast injection. Significant differences in f2 (contrast) and f10 (difference variance) were noted between partial responders and non-responders. Significant differences were also noted in f6 (sum average) and f15 (cluster shade) between node positive and node negative patients. Textural analysis of dynamic contrast enhanced data may have a role in predicting treatment response.

Bogumil-Krystian Debski¹, Wolfgang Bogner¹, Marek Chmelik¹, Katja Pinker², Thomas Helbich², Siegfried Trattnig¹, and Stephan Gruber^1
1MR Centre of Excellence, Dept. Radiology, Medical University of Vienna, Vienna, Vienna, Austria, ²Dept. Radiology, Medical University of Vienna, Vienna, Vienna, Austria

In this study we evaluate the capability of 3D-MRSI to monitor the treatment response of neoadjuvant chemotherapy in breast cancer. Eleven patients with histology proven breast cancer were measured before and after chemotherapy on a 3T scanner. Mean SNR-values of choline decreased by 94%, 84% and 21% for excellent, good and poor/non responder, respectively. Further, the number of voxels which contained choline decreased by 92%, 70% and 38% for excellent, good and poor/non responder, respectively. Therefore, the number of choline containing voxels could be an additional marker for treatment response. In conclusion 3D-MRSI can be applied for monitoring treatment response in a clinically feasible measurement time.

Nishat Bharwani¹, Marc E Miquel², Thomas Powles³, Redha Boubertakh², Anju Sahdev¹, Rodney H Reznek¹, and Andrea G Rockall^1
1Radiology, Barts and The London NHS Trust, London, United Kingdom, ²Medical Physics, Barts and The London NHS Trust, London, United Kingdom, ³Medical Oncology, Barts and The London NHS Trust, London, United Kingdom

In recent years there has been a shift in the treatment options available for metastatic renal cell carcinoma (RCC). There is a clinical need for early identification of subsets of patients who will respond to these new targeted therapies. To our knowledge, our work with sequential diffusion weighted MRI (DW-MRI) is the first to demonstrate that dynamic changes occur with sunitinib therapy. Correlation of these changes with overall survival is required to establish their prognostic significance. This work may therefore lead to the first steps towards individualized therapy in metastatic RCC.

Mark Alan Rosen¹, Yiqun Xue¹, Sarah Englander¹, Daniel Heitjian², Hyunseon S Kang¹, Anna Fagan¹, Naomi Haas³, William Lee³, William Carley⁴, Hee Kwon Song¹, Stephen Keefe³, and Yu Jiangsheng^1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, PA, United States,³Medicine, University of Pennsylvania, Philadelphia, PA, United States, ⁴Pfizer, Inc., Collegeville, PA, United States

Acquisition of hybrid radial projection DCE-MRI allows for large volume perfusional imaging with rapid temporal resolution in human tumor studies. We studied ten patients with metastatic RCC before and early after initiation of therapy with Sunitinib. Tumor Ktrans, kep and Ve were all significantly decreased after therapy. Inclusion of intra-tumoral vascular volume significantly altered the magnitude of tumor DCE-MRI metrics, and provided evidence of therapy-induced reductions in both tumor vascular permeability and tumor vascular volume.

Stephanie Hemmingson¹, Kelly Perlewitz², Megan Holtorf², Ian Tagge¹, William Woodward¹, Christopher Ryan², Charles Springer¹, and Wei Huang^1
1Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, United States, ²Medicine, Oregon Health & Science University, Portland, OR, United States

The ÄKtrans DCE-MRI parametric biomarker was tested on the first three soft-tissue sarcoma patients undergoing a phase I trial of antiangiogenic potentiatiated preoperative chemoradiotherapy. DCE-MRI data were acquired before therapy, after two weeks of antiangiogenic therapy only, and after eight more weeks of antiangiogenic therapy plus chemoradiotherapy. The % changes in tumor ROI and histogram median ÄKtrans values after two weeks provided superior early prediction of therapy pathologic response compared to those in tumor size and other kinetic parameters. Median ÄKtrans value after two weeks exhibited a linear relationship with the % necrosis of surgical specimens after ten weeks.

Junyu Guo¹, John O. Glass¹, Qing Ji¹, Catherine A. Billups², Najat C. Daw³, and Wilburn E. Reddick^1
1Translational Imaging Research, Radiological Sciences, St Jude Children's Research Hospital, Memphis, TN, United States, ²Biostatistics, St Jude Children's Research Hospital, Memphis, TN, United States, ³Division of Pediatrics, MD Anderson Cancer Center, Houston, TX, United States

We investigated the role of DCE-MRI in evaluating tumor histological response to preoperative chemotherapy and predicting overall and event-free survival (EFS) of pediatric patients with newly diagnosed nonmetastatic osteosarcoma in an international, multi-institutional trial. We found that DCE-MRI parameters K^trans and v_p at week 9 of neoadjuvant therapy could serve as surrogate biomarker for histological response. And DCE-MRI parameter v_e, the difference of v_e between outer and inner 50% of tumor at week 0, may be a true early prognostic factor for EFS and overall survival, which eventually could contribute to the development of risk-adapted therapy.

Rafal M Kedzierski¹, and Paul T. Weatherall^2
1Radiology, John Peter Smith Hospital, Fort Worth, Texas, United States, ²Radiology, Univ. of Texas Southwestern Medical Center, Dallas, Texas, United States

Assessment of the 3-Dimensional shape of bone lesions alone, frequently provides useful diagnostic information. Our data strongly supports the conclusion that a bone lesion that has a highly elliptical shape is very unlikely to represent a metastasis, if centrally located or otherwise unimpeded in its growth directions. This limited study showed a highly significant difference (p<0.01) in bone metastasis shape depending on the degree of contact with the cortical barrier of vertebral bodies.

Huyen Thanh Nguyen^1,2, Guang Jia¹, Zarine K Shah¹, Kamal S Pohar³, Amir Mortazavi⁴, Daniel Clark¹, Mitva Patel¹, Debra L. Zynger⁵, and Michael V Knopp^1,2
1Wright Center of Innovation in Biomedical Imaging and Department of Radiology, The Ohio State University, Columbus, OH, United States, ²Biophysics Program, The Ohio State University, Columbus, OH, United States, ³Department of Urology, The Ohio State University, Columbus, OH, United States, ⁴Department of Internal Medicine, The Ohio State University, Columbus, OH, United States, ⁵Department of Pathology, The Ohio State University, Columbus, OH, United States

The aim of this on-going study is to evaluate the usefulness of DCE-MRI in the assessment of neoadjuvant chemotherapeutic response of bladder cancer. A linear two-compartment pharmacokinetic model was used to calculate pharmacokinetic parameters and their maps. The results showed that DCE-MRI was able to increase significantly the accuracy of the assessment from 67% to 92%, reveal the changes in perfusion characteristics of bladder tumor due to the chemotherapy, and map out the responsive and non-responsive regions of bladder tumor. These promising results indicated that DCE-MRI is a reliable and powerful tool to assess and predict the neoadjuvant chemotherapeutic response of bladder cancer.

Yonggang Lu¹, Jacobus F.A. Jansen², Hilda E Stambuk¹, Nancy Lee¹, Jason A. Koutcher¹, and Amita Shukla-Dave^1
1Memorial Sloan-Kettering Cancer Center, New York, NY, United States, ²Maastricht University Medical Center, Maastricht, Netherlands

This study proposes to develop and implement a multi-parametric response mapping (mPRM) method by combining DWI, DCE MRI and T2 mapping in head and neck cancers. The method employs multiple MRI derived parameters to generate an integrated voxel-by-voxel response map. In this study, ADC (apparent diffusion coefficient), Ktrans (volume transfer constant) and T2 values (transverse relaxation time) were used to construct mPRM to assess early therapeutic efficacy. The parametric response indices provided from mPRM were compared with WHO response criterion. mPRM may provide more comprehensive information than the use of a single parameter for early assessment of treatment response.

Christina Messiou¹, Matthew Orton¹, David J Collins¹, Veronica A Morgan¹, Dorothy Mears², Isabel Castellano², Dionysis Papadatospastos³, Andre Brunetto³, Jooern Ang³, Helen Mann⁴, Jean Tessier⁴, Helen Young⁴, Stan Kaye³, Johann de Bono³, Martin O Leach¹, and Nandita M deSouza^1
1CRUK & EPSRC Cancer Imaging Centre, Institute of Cancer Research & Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom, ²Radiology, Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom, ³Dept of Medicine, Institute of Cancer Research & Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom, ⁴AstraZeneca, United Kingdom

The aim of this study was to establish within patient variability of DCE-MRI vs. DCE-CT in the same patients and compare their ability to measure changes in tumour blood flow and permeability in these patients when treated with the VEGFR tyrosine kinase inhibitor cediranib. Image parameters were reproducible-most were in the range 15-25%. The most reproducible parameter was DCE-MRI EF followed by DCE-MRI Ktrans and iAUC60, and DCE-CT PEI. DCE-MRI and DCE-CT were comparable when assessing changes from baseline in vascular physiology. There was generally a higher percentage change from baseline for parameters measuring area under the curve (iAUC60, PEI).

Martijn Intven¹, Onne Reerink¹, and Marielle E P. Philippens^1
1Radiotherapy, University Medical Centre, Utrecht, Netherlands

After neo-adjuvant radiochemotherapy (RCT) for locally advanced rectal cancer good pathological response correlates with good long term outcome. Reliable pathological response prediction is needed to enable safe omission of surgery in good responders. Diffusion weighted imaging showed already promising results in pathological response prediction. In this study tumour response was assessed with both fast and slow apparent diffusion coefficient (ADC) component analysis, which reflects the perfusion and diffusion contribution in the ADC value, respectively. 8 patients were analysed pre- and post-RCT. In both the fast and slow ADC values a larger increase correlated with a good pathological response.