Day 2 :
- Track 3: PET/MRI versus PET/CT Hybrid
Session Introduction
Mark G Benz
Engineering Horizons International and Safer Pediatric Imaging, USA
Title: Improved spatial resolution and lower-dose pediatric CT imaging: a feasibility study to evaluate narrowing the x-ray photon energy spectrum
Biography:
Benz is a metallurgist and currently working on new technologies to reduce the cancer risk associated with the x-ray dose for pediatric CT. From 1961 to 2001 Dr. Benz was on the research staff of the GE Corporate Research and Development Center. Dr. Benz is a graduate of Middlebury College (AB in Chemistry), and the Massachusetts Institute of Technology (SM and ScD in Metallurgical Engineering). He is a recipient of the GE Coolidge Fellowship, a Fellow of ASM International, and a Member of the National Academy of Engineering. He has presented 98 papers and has received 123 patents.
Abstract:
This feasibility study has shown that improved spatial resolution and reduced radiation dose can be achieved in pediatric CT by narrowing the x-ray photon energy spectrum. The approach used to evaluate narrowing the spectrum was to place a hafnium filter between the x-ray generator and a pediatric abdominal phantom. The CT platform used for this study was a GE system originally manufactured in 1999 in the process of being refurbished. This system had the advantage that it provided easy access to the x-ray portion of the system to add the hafnium filter. The observational measurements taken with the hafnium filter in place at 120 kVp showed a Spatial Resolution Metric of 2.3 mm at the low dose of 12 mGY. This is to be compared to the higher dose of 32 mGy required when the hafnium filter was not used. Further improvements are anticipated with installation of modified noise reduction software, currently under development. The research team completing this study included: Mark G Benz ScD, metallurgist retired from GE, consultant for Engineering Horizons International and Safer Pediatric Imaging; Matthew W. Benz MD, pediatrician with Southboro Medical Group; Steven B. Birnbaum MD, radiologist with Dartmouth Hitchcock; Eric Chason PhD and Brian W. Sheldon ScD, materials scientists with Brown University; and Dale McGuire, Director of CT Operations at BC Technical, Inc. A complete description of this study is published in Pediatric Radiology
Biography:
Marsha Haley, MD is board-certified in radiation oncology. She received her medical degree from the University of Virginia School of Medicine in Charlottesville, Va., and completed a residency in radiation oncology at the University of Pittsburgh School of Medicine. She is an Assistant Professor of Radiation Oncology at Magee-Womens Hospital of UPMC. She specializes in the treatment of breast and gynecological cancers. Her research interests include gynecological brachytherapy and the public health effects of unconventional gas extraction. She is a member of the American Brachytherapy Society and the American Society for Radiation Oncology.
Abstract:
MRI is a valuable tool for the radiation oncologist. Pretreatment MRI can be utilized as a tool to help plan radiation treatment portals, by delineating the extent of disease prior to chemotherapy and/or surgery. MRI can also be used post-operatively to assist with treatment planning. Advantages include superior anatomic delineation of soft tissue structures, improvement in lymph node imaging detail, and improved inter observer planning for the boost volume. Care studies include a case locally advanced breast cancer and a case of radiation treatment planning.
Anat Biegon
Stony Brook University, USA
Title: High contrast visualization of breast cancer lesions with [11C] vorozole PET
Biography:
Anat Biegon is Professor of Neurology and Radiology at Stony Brook University School of Medicine. She received a PhD in Neurobiology from the Weizmann Institute of Science in Rehovot, Israel and had held research positions in academia and industry. Employing state of the art brain mapping techniques in human subjects including molecular imaging with positron emission tomography (PET), structural and functional MRI, as well as post mortem analysis of human and animal brain samples, she is engaged in studies of the brain mechanisms affected in brain injury, stroke, Alzheimer’s disease and neuroinflammation. Her work includes development and validation of novel radiotracers and drugs for improving diagnosis and treatment of brain disorders.
Abstract:
More than a half of breast tumors are known to overexpress estrogen synthase (aromatase, Cyp19A gene product); and aromatase inhibitors are the mainstay of current hormonal adjuvant therapy in breast cancer. Vorozole is a potent aromatase inhibitor which was labeled with carbon11 and recently used to image aromatase with PET in healthy men and women. Here we describe the first case of breast cancer to be imaged with this tracer. A 68 year old woman recently diagnosed with stage 4 invasive lobular carcinoma was given 7.3 mCi [11C]vorozole intravenously. Forty minutes after injection, she was positioned in the prone position in a high resolution PET/CT (Siemens) scanner; with both breasts in the field of view. PET emission data were collected over a 50 minute period. The PET images revealed a large area of very high intensity in the left breast; corresponding in location and size to the diagnostic mammography; and multiple smaller regions with high intensity in the sternum and thoracic spine. The dynamic study included 5 frames of 10 min. duration each. Regions of interest (ROIs) were drawn with PMOD over the first frame and the corresponding time-activity curves were obtained. ROIs were placed in 2 locations of the carcinoma, in the breast adjacent to the tumor and in the contralateral breast. The ratio of tracer uptake in the tumor to the uptake in the same location in the contralateral breast ranged from 4.8 to 7.2 in the first frame (40-50 min). Both absolute uptake and ratio of tumor to contralateral breast decreased over time between 50 and 90 minutes post injection; suggesting a short (10-20min) acquisition may be sufficient. The [11C]vorozole PET image compares favorably with other imaging studies performed on the same patient, including FDG and MRI; supporting further investigation and optimization of this tracer in breast cancer.
Radim Jancalek
St. Anne’s University Hospital Brno, Brno, Czech Republic
Title: Developing role of advanced MRI techniques for diagnosis of glioblastoma relapse after complex oncology treatment
Biography:
Radim Jancalek has completed his PhD at the Masaryk University, Brno, Czech Republic. He started to be specialized in neurooncology, functional neurosurgery, and neuroimaging. He is the head of the Department of Neurosurgery, St. Anne’s University Hospital, Brno, Czech Republic, and the leader of the Neurooncology Research Group, St. Anne’s University Hospital. He has published more than 32 papers in reputed journals and has been serving as an editorial board member of repute.
Abstract:
Glioblastoma (GBM) is the most common primary brain tumor of adults. Despite a multidisciplinary approach, GBM frequently recurs as a new gadolinium-enhanced MRI lesion at or near the site of the original tumor; thus, at the site of high-dose target volume for radiotherapy. An early differentiation between GBM relapse and changes in connection with oncology treatment (pseudoprogression) is still problematic by common imaging techniques. The project goal was to verify whether the combination of apparent diffusion coefficient (ADC) and MR spectroscopy increases specificity of a structural MRI for early differentiation between HGG relapse and pseudoprogression. Patients (n=24) with GBM and structural progression on MRI after neurosurgical resection and chemo-radiotherapy underwent DWI (ADC map) and 1H MR spectroscopy focused on N-acetylaspartate (NAA), choline (Cho), creatine (Cr), lactate (Lac), and lipids (Lip). The etiology of a lesion was established by a subsequent MRI or biopsy and correlated with results of the MR techniques. Compared to pseudoprogression, HGG relapse was characterized by a significantly lower ADC value, lower NAA concentration, and appearance of Lac+Lip spectra. We found very high sensitivity and specificity of ADC value (≤1300x10-6 mm2/s) and Cho/NAA ratio (≥1.4) to designate the MRI lesion with gadolinium uptake as GBM relapse. ADC value and MRS (mainly Cho/NAA ratio) have ability for the early non-invasive differentiation of GBM relapse from pseudoprogression after oncology treatment.
Sangeeta Taneja
Indraprastha Apollo Hospitals, India
Title: Simultaneous whole body 18F-FDG PET-MRI in primary staging of breast cancer
Biography:
Sangeeta Taneja, completed her Masters in Radio-diagnosis in Jan 2003; a visiting fellow at Seattle Cancer care alliance (2008) & MSK, NY (2012), distinguished herself as a pioneering figure in MR Breast Imaging in India with largest cumulated experience & first to start MR guided breast interventions at Rajiv Gandhi Cancer Institute Delhi, has more than 25 scientific publications in reputed journal and reviewer to national and international journals, presently placed as Sr. consultant in Department of Molecular Imaging and Nuclear Medicine and an active member in the PET MRI project at Indraprastha Apollo Hospitals Delhi India.
Abstract:
Accurate initial staging in breast cancer is important for treatment planning and prognostication. The purpose of this study was to assess the utility of whole body simultaneous 18F-FDG PET-MRI in initial staging of breast carcinoma. Methods 36 patients of IDC of breast on histology underwent initial staging with whole body 18F-FDG PET-MRI on Biograph mMR (Siemens). Primary lesion, nodes and metastases were evaluated on PET, MRI and PET-MRI for lesion count and diagnostic confidence (DC). Kappa co relation analysis was done to assess agreement between PET and MRI. Histopathology, clinical/ imaging follow-up served as the reference standard. Results: 25 of 36 patients (37 index lesions) underwent surgery and 11 received NACT. Highest diagnostic confidence (DC=5) for index lesions obtained with PET MRI compared to PET and MRI alone. 2/36 (5.5%) patients were found to have synchronous contralateral cancer. MRI detected multifocality/multicentricity in 21 patients & 47 satellite lesions of which 23 were FDG avid. Sensitivity for axillary node detection was 60% and 93.3% with false negative rate of 40% and 6.7 % on PET and MRI respectively, and specificity for both was 91%. Distant metastases were found in 8/36 (22%) patients with 91 metastatic lesions on PET (DC>=4) and 105 on MRI (DC>=4) and found statistically significant (P=0.001). Overall PET-MRI led to a change in management in 12 (33.3%) patients. Conclusion: Simultaneous whole body18F-FDG PET-MR, has been found to be comprehensive single session examination in the initial staging of breast cancer.
Saira Naz Sufian
The Aga Khan University Hospital, Pakistan
Title: Accuracy of M.R.I in pretreatment lymph node assessment in gynecological malignancies
Biography:
Saira Naz Sufian is an Assistant Professor of Radiation Oncology at The Aga Khan University Hospital. She specializes in the treatment of breast and gynecological cancers. Her research interests include Evaluation of common risk factors related with Breast Carcinoma in females.
Abstract:
Objective: To determine the accuracy of MRI in detection of metastasis in pelvic and para-aortic lymph nodes from different gynecological malignancies. Place of study: Department of Diagnostic Radiology, Aga Khan University Hospital, Karachi Pakistan. Duration of study: From January 2011 to December 2012. Materials & Methods: It was a retrospective cross sectional analytic study. A sample of 48 women, age range between 20-79 years, fulfilling inclusion criteria were included. All patients had histopathologically proven gynecological malignancies including cervix, endometrium or ovaries and presented for a pretreatment MRI to our radiology department. Results: MRI is 100% sensitive and has 100 % positive predictive value to detect lymph node metastasis in lymph nodes with spiculated margins and it is 100 % sensitive and has 75 % positive predictive value to detect lymph node metastasis in a lymph node with lobulated margins. The sensitivity and positive predictive value of MRI to detect heterogeneous nodal enhancement were 100 % and 75 % respectively. Conclusion: Our study results reinforce that MRI should be used as a modality of choice in the pretreatment assessment of lymph node in proven gynaecological malignancies in order to determine the line of patient’s management, distinguishing surgical from non –surgical cases.
Biography:
Jacob Horsager is a 5th year medical student. He has finished a research year project and has recently published ‘Metabolic liver function measured in vivo by dynamic 18F-FDGal PET/CT without arterial blood sampling’ in EJNMMI Research.
Abstract:
Measurement of hepatic metabolic function by the Galactose Elimination Capacity (GEC) is a clinically valuable prognostic liver test for patients with acute as well as chronic liver disease. The GEC test is based on nearly exclusive hepatic metabolism of galactose by the galacto-kinase enzyme and gives a measure of the total hepatic metabolic function but no information on regional variations. Based on the principles of GEC, we developed a PET/CT method with the radio-labeled galactose analog 18F-FDGal for 3D-quantification of regional hepatic metabolic function in vivo. The 18F-FDGal PET/CT method comprises a 20-min dynamic PET recording of the liver with intravenous administration of 100MBq 18F-FDGal. 3D images of the metabolic capacity, in terms of hepatic systemic clearance of 18F-FDGal, are created using a model of irreversible metabolism of the tracer in liver tissue (measured by PET) and arterial blood 18F-FDGal concentration as input. Recently, we refined the method by developing a method for replacing arterial blood sampling by an image-derived input function extracted from the abdominal aorta. Using the method, we demonstrated low metabolic capacity as well as increased metabolic heterogeneity in cirrhosis. These findings demonstrate the importance of estimating regional variation in liver function in order to spare well-functioning liver tissue, e.g. in patients with liver tumors undergoing stereotactic radiotherapy or partial liver resection. The method is easy to implement, as 18F-FDGal is produced using commercially available equipment used for routine production of the common glucose tracer 18F-FDG.
Biography:
Heba Nabil, is a MD candidate, he got his Master degree of radio-diagnosis at Faculty of Medicine, Ain Shams University in 2008. He did his first part of MD in 2012 and first part of FRCR in 2013. He has published two papers named: Follow up in chest tumors: Value of integrated PET/CT and Role of PET/CT in management of chest tumors. He is working as a Radiology Specialist at Nasser Institute for research and treatment, Cairo, Egypt.
Abstract:
To identify the value of PET-CT in follow up of chest tumors. PATIENTS AND METHODS: Whole body PET/CT studies were performed on 29 patients of variable primary & secondary chest tumors. RESULTS: Our findings indicate that FDG PET/CT has an important impact on follow up of chest tumors, as it delineated the metabolic activity of the disease in 21 patients (72.41 %), outlined the metabolic activity of the tumoral residue in 4 patients postoperatively (13.79%), delineated the metabolic activity of the disease for preparing for BMT in 2 patient (6.89%). differentiated between tumoral residue & post irradiation pneumonitis in 1 patient (3.44%), and in 1 patient Initial assessment of the metabolic activity of the disease before determination line of treatment CONCLUSION: Integrated PET/CT imaging, which combines both functional and morphologic imaging in a single examination, has shown how the initial staging and subsequent follow-up of patients with chest tumors can supersede the traditional methods of evaluation in terms of diagnostic accuracy and has an impact on the management. Limitations which must be kept in mind are the subcentimetric pulmonary nodules that below 7 or 8 mm (beyond PET resolution).
Shivraj BahadurSingh
University of the West Indies, Trinidad and Tobago
Title: Mammographic Screening: Is it relevant to developing countries?
Biography:
Shivraj BahadurSingh is currently working on new technologies to reduce the cancer risk associated with the x-ray dose for pediatric CT and Mammographic Screening. He is currently working at University of the West Indies which is based at Trinidad and Tobago.
Abstract:
In the First world Mammogram screening for breast cancer is well established, its value, however, continues to be questionable. Multiple recent studies have shown that mammogram screening programs lead to increased costs and unnecessary further testing with no benefit to the patient. In developing countries clinical breast examination can be equally useful and more cost effective than mammograms, as shown by Mittra in 1995. Breast cancer presents at a later stage and in the pre-menapausal age group in the developing world. The unreliability of this modality as a screening tool is well recognized in this population thus further questioning its suitability. In many third world countries mammograms are costly and unavailable to the general population thus hindering screening. The different characteristics of breast cancer presentation in the third world coupled with cost and availability issues suggest that mammographic screening may not be beneficial in developing countries. Financial resources may be better directed to managing other aspects of the disease.