摘要:

Washington University has produced radioisotopes for medical application since the early 1960s. In order to serve seven PET scanners and to meet more stringent government regulations we have installed a new PET pharmacy based on our past years of experiences. The new pharmacy was installed at the site of the 3.7 MeV tandem cascade accelerator that was decommissioned in April of 2001. The pharmacy consists of a production lab, quality control lab, reagent preparation lab, shipping and storage area and an office. Security and safety was a main consideration in the design of this PET pharmacy. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619901

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Development of a Cyclotron manufacturing facility begins with a business plan. Geographics, the size and activity of the medical community, the growth potential of the modality being served, and other business connections are all considered. This business used the customer base established by NuTech, Inc., an independent centralized nuclear pharmacy founded by Danny Allen. With two pharmacies in operation in Tyler and College Station and a customer base of 47 hospitals and clinics the existing delivery system and pharmacist staff is used for the cyclotron facility. We then added cyclotron products to contracts with these customers to guarantee a supply. We partnered with a company in the process of developing PET imaging centers. We then built an independent imaging center attached to the cyclotron facility to allow for the use of short‐lived isotopes. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619902

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Commercial cyclotron systems used for 18F−production through 18O (p, n) 18F reaction face several conflicting requirements that include: reliability/uptime, quantity of consumables, safety, cost and yield. With commercialization of PET tracer distribution, higher yield has become one of the most important requirements. Maximizing yield for commercial cyclotrons require engineering trade‐off amongst several requirements, and often, to be conservative, significant design margin is kept while field feedback is collected. With maturing of technology, substantial experience has been obtained for a commercial cyclotron (PETtrace, GE Medical Systems), which is in use for several years. In this paper, we describe key elements of PETtrace commercial cyclotron technology undergoing enhancements, and share our works‐in‐progress experiments in performing critical engineering trade‐offs to improve 18F−yield. Three key parameters were tuned in this study within the design margin of the current equipment. First, we designed a second‐generation target assembly with optimized 18O water volume for accepting increased beam currents while maintaining cooling performance. Second, we increased the beam current of the ion source. And finally, a new RF driver amplifier was designed to enhance the RF power ratings to enable higher beam currents. Initial tests performed in the factory indicate substantially higher yield performance (> 50&percent;) reaching a peak yield of over 4 Ci per hour of bombardment in the new target. On dual targets, this extrapolates to 13.5 Ci/2hr of bombardment for a total target current of 120 &mgr;A. A target current of 100 &mgr;A is available in the existing design thus providing an 18F−production capacity exceeding 11 Ci/2hr. The preliminary experimental results are promising and illustrate successful exploitation of design margin to achieve increased yield for a commercial cyclotron. Long‐term studies to assess impact on life of ion source are underway along with a dedicated effort for achieving target currents in the excess of 120&mgr;A. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619903

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Beam scanning in proton therapy is a medical technique to lower the dose to healthy tissue while irradiating a tumor volume. Scanned proton beams for proton radiation therapy require small beam sizes at the tumor location. In beam scanning, a small beam usually less than 1 cm diameter is swept across the tumor volume with two magnets located several meters upstream of the patient. In general, all proton beams in a therapy facility must be transported from the accelerator to the treatment rooms where the scanning systems are located. This paper addresses the problem of transporting the beam without losses to the patient and achieving a small beam at the tumor location in the patient. The strengths of the beam line quadrupoles were allowed to vary to produce the desired beam sizes along the beam lines. Quadrupole strengths were obtained using the beam simulation program TRANSPORT originally from Stanford Linear Accelerator Center in Palo Alto, CA. An enhanced version of the original program by Accel Soft Inc. in San Diego, CA has been used for these studies. Beam size measurements were used for comparison with TRANSPORT to verify the predictions of TRANSPORT calculations. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619904

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

The escalating clinical application of Positron Emission Tomography results from the novel radiotracers which are available to monitor specific biochemical or physiologic processes. Future developments of the technique will require an increasing availability of additional unique radioligands and radionuclides. Iodine‐124, a radionuclide whose potential for both diagnostic and therapeutic applications is widely recognized, has been prepared at Memorial Sloan‐Kettering Cancer Center on a weekly basis for several years (1). With its characteristic 4.18 day half life and complex decay scheme (2) which includes positron emission (22.0 ± 0.5&percent;) and electron capture (78 ± 0.5&percent;), this radionuclide has been shown to be appropriate for radiotracers describing slow physiologic processes with the clearance of non‐specific radioactivity. The refinements and modifications being engineered into the cyclotron target system to increase the absolute yield of recoverable radioactivity from each irradiation and its chemical processing of the reusable solid target matrix are described.. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619905

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Lung clearance of51CR and125I iododeoxyuridine (IUDR) labeled cancer cells assess NK cell activity. It is desirable to develop noninvasive imaging technique to assess NK activity in mice. We labeled target YAC‐1 tumor cells with125I,111In,99mTc, or67Ga and injected I.V. into three groups of BALB/c mice. Animals were treated with medium (group I), 300mg/kg cyclophosmamide (CY) to kill NK cell (group II), or anti‐LY49C/1) (ab’)2mAb to augment NK function (group III). Lungs were removed 15 min or 2 h later for tissue counting. Control and treated mice were imaged every 5 min with a scintillating camera for 1 h after 15 min of infusion of the111In labeled cells. Lung clearance increased after 15 min (lodging: 60–80&percent;) and (2 h retention: 3–7&percent;). Similar results were obtained with all the isotopes studied. Images distinguished the control and treated mice for lung activity. Cells labeled with111In,99mTc or67Ga are cleared similar to those labeled with51Cr or125I. NK cell destruction of tumor cells may be assessed by noninvasive imaging method either by SPECT (99mTc,111In,67Ga) or by PET (68Ga). © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619906

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Approximately 10 ml of O‐18 water was loaded in an apparatus containing a 5 ml storage vessel, pump, silver target attached to a cyclotron, filter, backpressure regulator, conductivity meter, several valves and ion exchange cartridges. The water was continuously pumped through the target during proton bombardment at a rate 5 ml/min. Continuous irradiation with beam current ranging from 10 to 50 uA was conducted while pressure, temperature and conductivity were continuously monitored. The results indicate that recirculating of the target water can increase production of F‐18 in relation to consumed O‐18 water material. It can also increase productivity by eliminating idle periods for re‐filling the target. A backpressure regulator can precisely control target pressure. This method also allows for continuous monitoring of the target material temperature, pressure, conductivity and accumulated radioactivity. Results of these observations provide important information about target performance and physical processes taking place inside the target. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619907

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Several alpha emitting isotopes have been proposed for radioimmunotherapy. To produce these nuclides reliably and in quantities needed, unique manufacturing approaches will be required. This paper describes the approaches that are being developed for the manufacture of225Actinium (225Ac) that decays to213Bismuth (213Bi) and the commercial manufacturing approaches. Oak Ridge National Laboratory (ORNL) currently supplies the actinium used for research and medical use. Today the ORNL233U stockpiles only provide sufficient material for research quantities of213Bi. At the Institute for Transuranium Elements (ITU), in Karlsruhe, researchers have also developed a method of irradiating radium‐226 with protons in a cyclotron to produce actinium‐ 225 through the reaction226Ra (p, 2n)225Ac. Researchers from the Missouri University (MU), the Missouri University Research Reactor (MURR), MedActinium, Inc. and Los Alamos National Laboratory (LANL) are working on a collaborative effort to benchmark and optimize the production of213Bi via neutron bombardment of226Ra. MedActinium, Inc., in collaboration with commercial and institutional investigators at PG Research Foundation (PGRF) and Memorial Sloan Kettering Cancer Center (MSKCC), is developing commercial approaches to manufacturing these unique radioimmunotherapeutic drugs. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619908

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

The Indiana University Cyclotron Facility (IUCF) is in the process of designing and building the Midwest Proton Radiation Institute (MPRI) [1]. The design process includes the development of several patient treatment systems. This paper discusses the use of two such systems that provide for the high precision positioning of a patient. They are the Patient Positioner System and the X‐ray system. The Patient Positioner System positions an immobilized patient on a support device to a treatment position based on a prescribed Treatment Plan. The X‐ray system uses an industrial robot arm to position a Digital Radiography Panel to acquire an X‐ray image to verify the location of the prescribed treatment volume in a patient by comparing the acquired images with reference images obtained from the patient’s Treatment plan. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619909

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

The Heavy Ion Medical Accelerator in Chiba (HIMAC) is the world’s first heavy ion accelerator complex dedicated to medical use in a hospital environment. Heavy ions have superior depth‐dose distribution and greater cell‐killing ability. In June 1994, clinical research for the treatment of cancer was begun using carbon ions generated by HIMAC. Until August 2002, a total of 1,297 patients were enrolled in clinical trials. Most of the patients had locally advanced and/or medically inoperable tumors. Tumors radio‐resistant and/or located near critical organs were also included. The clinical trials revealed that carbon ion radiotherapy provided definite local control and offered a survival advantage without unacceptable morbidity in a variety of tumors that were hard to cure by other modalities. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1619910

出版商:AIP    

年代:1903

数据来源: AIP