James Halama

Recommendations of the American Association of Physicists in Medicine on dosimetry, imaging, and quality assurance procedures for 90Y microsphere brachytherapy in the treatment of hepatic malignancies.

Yttrium-90 microsphere brachytherapy of the liver exploits the distinctive features of the liver anatomy to treat liver malignancies with beta radiation and is gaining more wide spread clinical use. This report provides a general overview of microsphere liver brachytherapy and assists the treatment team in creating local treatment practices to provide safe and efficient patient treatment. Suggestions for future improvements are incorporated with the basic rationale for the therapy and currently used procedures. Imaging modalities utilized and their respective quality assurance are discussed. General as well as vendor specific delivery procedures are reviewed. The current dosimetry models are reviewed and suggestions for dosimetry advancement are made. Beta activity standards are reviewed and vendor implementation strategies are discussed. Radioactive material licensing and radiation safety are discussed given the unique requirements of microsphere brachytherapy. A general, team-based quality assurance program is reviewed to provide guidance for the creation of the local procedures. Finally, recommendations are given on how to deliver the current state of the art treatments and directions for future improvements in the therapy.

AAPM Task Group 108: PET and PET/CT Shielding Requirements

The shielding of positron emission tomography (PET) and PET/CT (computed tomography) facilities presents special challenges. The 0.511 MeV annihilation photons associated with positron decay are much higher energy than other diagnostic radiations. As a result, barrier shielding may be required in floors and ceilings as well as adjacent walls. Since the patient becomes the radioactive source after the radiopharmaceutical has been administered, one has to consider the entire time that the subject remains in the clinic. In this report we present methods for estimating the shielding requirements for PET and PET/CT facilities. Information about the physical properties of the most commonly used clinical PET radionuclides is summarized, although the report primarily refers to fluorine-18. Typical PET imaging protocols are reviewed and exposure rates from patients are estimated including self-attenuation by body tissues and physical decay of the radionuclide. Examples of barrier calculations are presented for controlled and noncontrolled areas. Shielding for adjacent rooms with scintillation cameras is also discussed. Tables and graphs of estimated transmission factors for lead, steel, and concrete at 0.511 MeV are also included. Meeting the regulatory limits for uncontrolled areas can be an expensive proposition. Careful planning with the equipment vendor, facility architect, and a qualified medical physicist is necessary to produce a cost effective design while maintaining radiation safety standards.

Photodynamic therapy for intracranial neoplasms: investigations of photosensitizer uptake and distribution using indium-111 Photofrin-II single photon emission computed tomography scans in humans with intracranial neoplasms.

Photodynamic therapy is being investigated as an adjuvant treatment for intracranial neoplasms. The efficacy of this therapy is based on the uptake of photosensitizer by neoplastic tissue, its clearance from surrounding brain tissue, and the timing and placement of photoactivating sources. Photofrin-II is the photosensitizer most actively being investigated. We labeled Photofrin-II with Indium-111 and studied the uptake and distribution of this agent in 20 patients with intracranial neoplasms, using single photon emission computed tomography (SPECT) with volume rendering in three dimensions. Of these patients, 16 had malignant glial tumors, 2 had metastatic deposits, 1 had a chordoma, and 1 had a meningioma. Anatomical-spatial data correlated well between the SPECT images and contrast-enhanced computed tomography or magnetic resonance images. Regions of focal uptake on SPECT images correlated with the surgical histopathological findings of the neoplasm. The kinetics of photosensitizer uptake varied according to the tumors histological findings, the patients use of steroids, and among patients with similar types of tumor histology. Peak ratios of target-to-nontarget tissue varied from 24 to 72 hours after injection. The study data show that, to be most effective, photodynamic therapy may need to be tailored for each patient by correlating SPECT images with anatomical data produced by computed tomography or magnetic resonance images. Photoactivating sources then can be placed, using computer-assisted stereotactics, to activate a prescribed volume of photosensitized tumor at the optimal time for treatment.

Effect of Silicone Gluteal Implant on Bone Mineral Density Evaluation by DXA Scan

Aamna Hassan,* Erin Grady, Joseph Ringelstein, James R. Halama, Alaleh Mazhari, and Nicholas C. Friedman Department of Nuclear Medicine, Hines VA Medical Center, Hines, IL, USA; Department of Nuclear Medicine, Loyola University Medical Center, Maywood, IL, USA; Department of Radiology, Section of Nuclear Medicine, Loyola University Medical Center, Maywood, IL, USA; and Department of Endocrinology, Loyola University Medical Center, Maywood, IL, USA

Proof of Concept: Design and Initial Evaluation of a Device to Measure Gastrointestinal Transit Time

Chronic constipation and gastrointestinal motility disorders constitute a large part of a gastroenterology practice and have a significant impact on a patients quality of life and lifestyle. In most cases, medications are prescribed to alleviate symptoms without there being an objective measurement of response. Commonly used investigations of gastrointestinal transit times are currently limited to radiopaque markers or electronic capsules. Repeated use of these techniques is limited because of the radiation exposure and the significant cost of the devices. We present the proof of concept for a new device to measure gastrointestinal transit time using commonly available and inexpensive materials with only a small amount of radiotracer. Methods: We assembled gelatin capsules containing a 67Ga-citrate–radiolabeled grain of rice embedded in paraffin for use as a point-source transit device. It was tested for stability in vitro and subsequently was given orally to 4 healthy volunteers and 10 patients with constipation or diarrhea. Imaging was performed at regular intervals until the device was excreted. Results: The device remained intact and visible as a point source in all subjects until excretion. When used along with a diary of bowel movement times and dates, the device could determine the total transit time. The device could be visualized either alone or in combination with a barium small-bowel follow-through study or a gastric emptying study. Conclusion: The use of a point-source transit device for the determination of gastrointestinal transit time is a feasible alternative to other methods. The device is inexpensive and easy to assemble, requires only a small amount of radiotracer, and remains inert throughout the gastrointestinal tract, allowing for accurate determination of gastrointestinal transit time. Further investigation of the device is required to establish optimum imaging parameters and reference values. Measurements of gastrointestinal transit time may be useful in managing patients with dysmotility and in selecting the appropriate pharmaceutical treatment.

Managing Written Directives: A Software Solution to Streamline Workflow

A written directive is required by the U.S. Nuclear Regulatory Commission for any use of 131I above 1.11 MBq (30 μCi) and for patients receiving radiopharmaceutical therapy. This requirement has also been adopted and must be enforced by the agreement states. As the introduction of new radiopharmaceuticals increases therapeutic options in nuclear medicine, time spent on regulatory paperwork also increases. The pressure of managing these time-consuming regulatory requirements may heighten the potential for inaccurate or incomplete directive data and subsequent regulatory violations. To improve on the paper-trail method of directive management, we created a software tool using a Health Insurance Portability and Accountability Act (HIPAA)–compliant database. This software allows for secure data-sharing among physicians, technologists, and managers while saving time, reducing errors, and eliminating the possibility of loss and duplication. Methods: The software tool was developed using Visual Basic, which is part of the Visual Studio development environment for the Windows platform. Patient data are deposited in an Access database on a local HIPAA-compliant secure server or hard disk. Once a working version had been developed, it was installed at our institution and used to manage directives. Updates and modifications of the software were released regularly until no more significant problems were found with its operation. Results: The software has been used at our institution for over 2 y and has reliably kept track of all directives. All physicians and technologists use the software daily and find it superior to paper directives. They can retrieve active directives at any stage of completion, as well as completed directives. Conclusion: We have developed a software solution for the management of written directives that streamlines and structures the departmental workflow. This solution saves time, centralizes the information for all staff to share, and decreases confusion about the creation, completion, filing, and retrieval of directives.

MO‐AB‐206‐02: Testing Gamma Cameras Based On TG177 WG Report

This education session will cover the physics and operation principles of gamma cameras and PET scanners. The first talk will focus on PET imaging. An overview of the principles of PET imaging will be provided, including positron decay physics, and the transition from 2D to 3D imaging. More recent advances in hardware and software will be discussed, such as time-of-flight imaging, and improvements in reconstruction algorithms that provide for options such as depth-of-interaction corrections. Quantitative applications of PET will be discussed, as well as the requirements for doing accurate quantitation. Relevant performance tests will also be described. LEARNING OBJECTIVES 1. Be able to describe basic physics principles of PET and operation of PET scanners. 2. Learn about recent advances in PET scanner hardware technology. 3. Be able to describe advances in reconstruction techniques and improvements 4. Be able to list relevant performance tests. The second talk will focus on gamma cameras. The Nuclear Medicine subcommittee has charged a task group (TG177) to develop a report on the current state of physics testing of gamma cameras, SPECT, and SPECT/CT systems. The report makes recommendations for performance tests to be done for routine quality assurance, annual physics testing, and acceptance tests, and identifies those needed satisfy the ACR accreditation program and The Joint Commission imaging standards. The report is also intended to be used as a manual with detailed instructions on how to perform tests under widely varying conditions. LEARNING OBJECTIVES At the end of the presentation members of the audience will: 1. Be familiar with the tests recommended for routine quality assurance, annual physics testing, and acceptance tests of gamma cameras for planar imaging. 2. Be familiar with the tests recommended for routine quality assurance, annual physics testing, and acceptance tests of SPECT systems. 3. Be familiar with the tests of a SPECT/CT system that include the CT images for SPECT reconstructions. 4. Become knowledgeable of items to be included in annual acceptance testing reports including CT dosimetry and PACS monitor measurements. T. Turkington, GE Healthcare.

TU‐A‐342‐01: Quality Assurance Testing of Gamma Camera and SPECT Systems

Routine maintenance, calibration, and quality control of gamma camera and SPECTimaging systems is crucial for providing the nuclear physician or radiologistimages of high quality without artifact. This lecture will provide an overview of the gamma camera and SPECTcalibrations, performance measurements, and quality assurance tests, whether they are for routine quality control or annual physics surveys as defined by the ACR accreditation program. A discussion of common artifacts and how to avoid and correct them will be included. Gamma camera and SPECT performance measurements are well defined in documents published by MITA/NEMA and in AAPM Task Group reports. Unfortunately, many of the specified tests cannot be easily done on installed systems in the field. Modifications become necessary, and as a result performance measurements and quality assurancetesting of gamma camera and SPECT systems have been quite variable. Not included in the published documents are calibration procedures that are vendor specific. Improper calibrations, particularly uniformity calibration, also lead to unwanted artifacts. It is the burden of the physicist to know which performance tests are critical in the field and to also become familiar with specific calibration procedures of our gamma camera and SPECT systems. Educational Objectives: 1. Learn the basic gamma camera and SPECT performance measurements and quality assurance test procedures. 2. Become familiar with calibration procedures of current systems. 3. Become familiar with the test procedures and the frequency of testing prescribed by the ACR accreditation programs. 4. Be able to identify common gamma camera and SPECTimage artifacts and how to correct them.

TU‐A‐M100J‐01: Quality Assurance and Acceptance Testing of Gamma Camera and SPECT Systems

The general purpose gamma camera and those configured for SPECT are the bread‐and‐butter imaging instruments in nuclear medicine, and remains the principle component in systems specifically designed for cardiacSPECT. Routine maintenance, calibration, and quality control of these imaging systems is crucial for providing the nuclear physician or radiologist images of high quality without artifact, the bane of nuclear medicine imaging. Acceptance testing, for the most part, provides baseline measurements that are used as reference data for future comparisons. Performance measurements and quality assurancetesting of gamma camera and SPECT have been quite variable. The vendors are very specific about calibration procedures that are done one site, but the quality assurancetesting by the customer are left up to the individual laboratories that vary to a large part based on the expertise of the staff. Federal and state radiation safety regulatory agencies purposely do not include any gamma cameraquality assurancetesting in their regulations. There are now two nuclear medicine accreditation programs, one by the American College of Radiology (ACR) and the other by the Intersocietal Commission for Accreditation of Nuclear Medicine Laboratories (ICANL), that have sought to standardize nuclear medicine imaging and quality assurance procedures performed. Also specified are the qualifications of the personnel who perform and interpret the imaging results. This lecture will provide an overview of the gamma camera and SPECTcalibrations, performance measurements, and quality assurance tests, whether they are for acceptance testing or routine quality control. NEMA, ACR and ICANL accreditation program documents, and AAPM Task Group reports will be used as a backdrop for the presentation. A discussion of common image artifacts and how to avoid and correct them will also be included. Educational Objectives: 1. Learn the basic gamma camera and SPECT performance measurements and quality assurance test procedures. 2. Become familiar with the test procedures and the frequency of testing prescribed by the ACR and ICANL accreditation programs. 3. Be able to identify common gamma camera and SPECTimage artifacts and how to correct them.