Hedvig Hricak

Kirsten Margrete Selnæs^1,2, Mattijs Elschot¹, Brage Krüger-Stokke^1,3, Øystein Størkersen⁴, Dag Linthoe Halvorsen⁵, Elise Sandsmark¹, May-Britt Tessem^1,2, Sverre Langørgen³, Eirik Kjøbli⁵, Anders Angelsen¹, Frode Willoch^6,7, Helena Bertilsson^5,8, Siver Andreas Moestue^1,2, and Tone Frost Bathen^1,2
1Department of Sirculation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway, ²St. Olavs University Hospital, Trondheim, Norway, ³Clinic of Radiology and Nuclear Medicine, St. Olavs University Hospital, Trondheim, Norway, ⁴Clinic of Laboratory Medicine, St. Olavs University Hospital, Trondheim, Norway, ⁵Clinic of Surgery, St. Olavs University Hospital, Trondheim, Norway, ⁶Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway, ⁷Aleris Cancer Center, Oslo, Norway, ⁸Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway

The leucine amino acid analog 1-amino-3-fluorine 18-fluorocyclobutane-1-carboxylic acid (18F-FACBC) has shown promising results in assessment of primary and metastatic prostate cancer. In the present study a protocol for simultaneous 18F-FACBC PET and multiparametric MR was established and evaluated with respect to the diagnostic potential (N-stage and grade) in high risk prostate cancer patients. The preliminary results show that there is high tracer uptake in regions corresponding to tumor within the gland, however, areas of BPH has also been observed to have high uptake. Histopathologically verified lymph node metastasis also show high uptake of tracer.

N Jane Taylor¹, Kent Yip², Juliette Valentine², J James Stirling¹, Ian C Simcock¹, David J Collins³, James A d'Arcy³, Uma Patel², Andrew Gogbashian¹, Peter Hoskin², Anwar R Padhani¹, and Roberto Alonzi^2
1Paul Strickland Scanner Centre, Mount Vernon Hospital, London, United Kingdom, ²Marie Curie Research Wing, Mount Vernon Cancer Centre, London, United Kingdom, ³Cancer Research-UK-EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom

Hypoxia correction improves survival in patients treated with radiotherapy (RT) for some cancers. Previous studies have shown the existence of hypoxia in untreated prostate cancer (PCa) and hypoxia resolution following carbogen breathing. Androgen deprivation therapy (ADT) is normally given prior to RT. ADT is anti-angiogenic and causes tumour vascular disruption. It is not known whether the use of carbogen gas will still be effective in correcting hypoxia post ADT. This study has assessed this during hypoxia-modified RT.

Pelin Aksit Ciris^1,2, Robert V. Mulkern^2,3, Mukund Balasubramanian^2,3, Ravi T. Seethamraju⁴, Janice Fairhurst¹, Junichi Tokuda^1,2, Jonathan Scalera^1,2, Tobias Penzkofer^1,2, Fiona Fennessy^2,5, Ferenc A. Jolesz^1,2, Clare M. Tempany-Afdhal^1,2, Ehud Schmidt^1,2, and Kemal Tuncali^1,2
1Brigham and Women's Hospital, Boston, MA, United States, ²Harvard Medical School, Boston, MA, United States, ³Boston Children's Hospital, Boston, MA, United States, ⁴Siemens Healthcare, Boston, MA, United States, ⁵Dana-Farber Cancer Institute, MA, United States

Hypoxia is prevalent in prostate cancer, and may indicate cancer aggressiveness. Oxygenation, among many other factors, can influence gradient-echo signal decay in the prostate, appropriate characterization of which is essential for any potential quantitative use. A standard Mono-Exponential (ME) decay model has shown promise at 1.5T, however, we report that proper signal characterization requires a Gaussian Augmentation of the Mono-Exponential (GAME) decay model at 3T. GAME characterized signal decays better than or equivalent to ME everywhere in the prostate. This increases the potential for determining correlates of the fit parameters with biomarkers, such as of oxygenation status.

Harsh K Agarwal^1,2, Sandeep Sankineni², Marcelino Bernardo^2,3, Bradford Wood², Peter Pinto², Peter L Choyke², and Baris Turkbey^2
1Philips Research NA, Briarcliff Manor, New York, United States, ²National Institutes of Health, Bethesda, MD, United States, ³Frederic National Laboratory for Cancer Research, Leidos Biomedical Research Inc., Frederick, MD, United States

): Low mortality rate of indolent prostate cancer is motivating patients to choose active survelliance. However there are limited number of quantitative tools to monitor the patients on active survelliance with imaging. T2 contrast in prostate MRI has a potential to monitor the patient on active surveliance. This is study we have shown that Quantitative T2 histogram analysis can be potentially utilized as an efficient, and quick visual method of determining status of active surveillance with high negative predictive value for low-risk prostate cancer patients.

Nikolaos Dikaios^1,2, Jokha Alkalbani², Alex Kirkham³, Clare Allen³, Hashim Ahmed⁴, Mark Emberton⁴, Alex Freeman⁵, Steve Halligan², Stuart Taylor², David Atkinson², and Shonit Punwani^2
1Medical Physics, UCL, London, Greater London, United Kingdom, ²Centre of Medical Imaging, UCL, Greater London, United Kingdom, ³Radiology, UCL, Greater London, United Kingdom, ⁴Urology, UCL, Greater London, United Kingdom, ⁵Histopathology, UCL, Greater London, United Kingdom

Multi-parametric MRI (mp-MRI) facilitates identification of transition zone cancers, yet its overall diagnostic accuracy is likely lower in this part of the prostate compared with the peripheral zone. Benign hyperplastic nodules within the transition zone likely make the localisation of cancer difficult. Logistic regression (LR) models1 for classifying transition zone (TZ) prostate cancer (PCa) on mp-MRI were previously derived and validated. Here we explore whether the application of support vector machine (SVM) neural network (SVNN) algorithms can improve classification accuracy. The proposed SVNN algorithm is trained on 70 patients and temporally validated on a second independent cohort of 85 patients.

Raisa Z Freidlin¹, Harsh K Agarwal², Sandeep Sankineni³, Anna M Brown³, Marcelino Bernardo^3,4, Peter A Pinto³, Bradford J Wood³, Deborah E Citrin³, Peter L Choyke³, and Baris Turkbey^3
1NIH/CIT, Bethesda, Maryland, United States, ²Philips Research, New York, United States, ³NIH/NCI, Maryland, United States, ⁴Leidos, Maryland, United States

Existing studies using diffusion MRI models for prostate cancer (PCa) detection have not used an unsupervised approach. Our proof-of-concept study introduces a novel unsupervised multi-characteristic framework for localizing PCa. Our framework calculates voxel-based parameters from the IVIM and kurtosis models and identifies “tumor” and “tumor suspicious” voxels using patient-specific thresholds. Ten patients with moderate-high clinicopathological risk for PCa underwent 3T prostate MRI and subsequent biopsy. The index lesion was identified in all patients (100% patient-based detection rate). Of the 25 framework-identified lesions, 14 were true positives (56% lesion-based detection rate). This novel framework shows promise for identifying index PCa lesions.

Radka Stoyanova¹, Sakhi Abraham¹, Adrian Breto¹, Zheng Ao², Anthony Williams², Jorge Torres-Munoz², Ram Datar², Richard Cote², Yosef Zeidan¹, Adrian Ishkanian¹, Matthew Abramowitz¹, and Alan Pollack^1
1Radiation Oncology, University of Miami, Miami, Florida, United States, ²Pathology, University of Miami, Miami, Florida, United States

Circulating tumor cells (CTC) are rare malignant cells found in the peripheral blood of patients with a wide range of solid tumors. In this study we investigated the correlation of CTC counts with the prostate tumor volume, tissue perfusion and diffusion properties, estimated from multiparametric (MP)-MRI. These imaging biomarkers were related to CTC counts in patients enrolled in a contemporary randomized clinical trial for definitive radiotherapy of prostate cancer. This is, to our knowledge, the first study comparing CTC counts with in vivo measurements of tumor volume, perfusion and diffusion.

Hsin-Yu Chen^1,2, Peder E.Z. Larson^1,2, Robert A. Bok², Cornelius von Morze², Romelyn Delos Santos², Renuka Sriram², Justin Delos Santos², John Kurhanewicz^1,2, and Daniel B. Vigneron^1,2
1Graduate Program in Bioengineering, UCSF and UC Berkeley, San Francisco, California, United States, ²Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, United States

A major challenge in the clinical management of prostate cancer is the differentiation of aggressive cancer from indolent disease. We developed a novel protocol using dynamic 3D compressed sensing EPSI to quantitatively assess aggressive prostate cancer on transgenic mouse model of prostate cancer (TRAMP) using dual agent hyperpolarized [C13]-pyruvate & [C13]-urea for simultaneous metabolic and perfusion MR. The dynamic HP [C13] results demonstrated significantly (P<.001) higher rates of lactate production and lower perfusion (P<.003) in high grade tumors versus low grade.

Nassim Tayari¹, Isabell K. Steinseifer¹, Cai Xia Fu², Elisabeth Weiland³, Jack J.A. van Asten¹, Tom W.J. Scheenen⁴, Marnix C Maas¹, and Arend Heerschap^1
1Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, Netherlands, ²Siemens Shenzhen Magnetic Resonance Ltd., China, ³Siemens Healthcare, Erlangen, Germany, ⁴Department of Radiology and Nuclear Medicine, Radboud university medical center, Nijmegen, Netherlands

The use of an endorectal coil (ERC) in MR of the prostate is time consuming and uncomfortable for patients. In this work we demonstrate that robust 1H MRSI of the prostate can be performed without ERC by a semi-LASER sequence with GOIA-WURST(16,4) refocusing pulses. This sequence has an excellent performance as reflected by high citrate signals and minor lipid contamination. Furthermore, acquisition times can be shortened to 5 min (TR = 630 ms), which is clinically valuable. For the detection of the choline signal, a TR of about 900 ms is more favorable, to avoid too much signal saturation.