Clinical Program: Medical Physics Group 2001

• Seattle Cancer Care Alliance: The radiation equipment at the SCCA was commissioned and routine physics support of the clinic was implemented.
• RTOG: Provided physics support for RTOG application, which was accepted.
• Virtual Compensators: Multiple beam segments designed to produce uniform target doses were implemented. The primary application has been in treatment of breast cancer. This work required a number of new algorithms be implemented, new QA procedures, and the implementation of DICOM-RT (see below).
• Intravascular Brachytherapy: Working with the Cardiology Department, we started performing IVB for coronary restonosis.
• Pediatric TBI: The joint agreement between Children's Hospital, FHCRC, and UWMC means that we are now responsible for a certain number of pediatric TBI cases. A patient positioning stand was designed and built, and the dosimetry was commissioned.
• Total Skin Electrons: Total skin irradiations with electrons had been performed on the Cl 2500. This technique was re-commissioned on the SL20C using a re-designed patient positioning stand.
• In Vivo Dosimetry: Direct measurement of the dose delivered to the surface of the patient for each field was instituted by means of a multiple diode dosimetry system. This replaces a manual inspection of data entered into the SL20 computer to verify that the correct machine parameters have been set up for each different field.
• Direct Treatment Data Transfer: The DICOM-RT protocol for transferring data from Prism to the Elekta linacs was implemented in Prism. The software made use of the programming innovations that arose from our earlier development of the DICOM image transfer protocol that was implemented in Prism. In addition to increasing the quality of data transfer, it also paved the way for the introduction of more complex treatment techniques, such as compensated fields and IMRT.
• Prism: During this past year, a number of enhancements were included in Prism. In addition to many small improvements designed to make dosimetrists' life easier, major innovations included:
  • implementation of planning tools to calculate "virtual" compensators by means of multiple segmented beams (implemented for treatment of breast cancer);
  • inclusion of OpenGL support for enhanced image manipulation and display;
  • development and implementation of DICOM-RT code for direct Prism to linac plan setup;
  • inclusion of electron dose calculations (currently, the data are being inspected before clinical release).
• Computer Security/Administration: Mark Wagner was hired (jointly with Radiology Dept.) to improve computer security and administration.
• Provided clinical support: As part of our routine work, we provided clinical support for the following programs at UWMC and at the Seattle Cancer Care Alliance.
  • External beam therapy (x-rays, electrons, neutrons)
  • Intra-operative radiation therapy with electrons
  • Total body irradiation
  • Total skin electron irradiation
  • Intravascular brachytherapy
  • Stereotactic radiotherapy
  • Stereotactic radiosurgery
  • General brachytherapy
  • Eye Plaques
  • High Dose Rate brachytherapy
  • Permanent prostate implant brachytherapy
  • Permament implant brachytherapy for other sites
• Provided quality assurance and maintanence support: As part of our routine work, we provided quality assurance and maintanence support for the following UWMC and/or SCCA systems:
  • Linear accelerators
  • Cyclotron
  • Gamma Knife
  • Radiocamera system
  • High dose rate afterloader
  • Intravascular brachytherapy device
  • Brachytherapy systems (high and low dose rate)
  • Treatment planning systems:
  • External beam therapy with x-rays and neutrons (Prism)
  • Stereotactic radiosurgery
  • Stereotactic radiotherapy
  • High dose rate brachytherapy
  • Permanent prostate implant brachytherapy
  • Departmental computers for research and treatment planning
• Operations and upgrades of the neutron therapy system (with Ruedi Risler, David Reid, Robert Emery James Kuan, Eric Dorman, Jon Jacky):
  • Provided neutron beam for ongoing neutron therapy
  • Provided proton beam for PET radionuclide production
  • Provided alpha beam once a month for 211-Astatine production
  • Operated and maintained the clinical cyclotron with less than 1% of the scheduled patient sessions cancelled for technical reasons
  • Upgraded both Modicon programmable logic controllers to the latest Quantum processors
  • Changed the connection from the therapy control computer to the two Modicon controllers to Ethernet using our private network
  • Continued changing therapy motion controls from the original relay controls to a new combination of Modicon and relay control.
  • Replaced two thirds of the original 500 series I/O modules of Modicon 1 by Quantum type modules.
  • Continued preparations for a major seismic upgrade by re-routing control area cabling, getting equipment stabilization brackets manufactured and getting holes drilled into the equipment for the installation of hold-down anchors.
  • Increased the alpha beam output to 60 uA on the first Faraday cup
  • Replaced several quadrupole power supplies by new units which can be digitally controlled in the future
  • Continued preparation work for a future move of the cyclotron and beam line controls away from the PDP 11/23
  • Continued the investigation of neutron production targets for a therapy beam with enhanced boron neutron capture capabilities by building and characterizing 6 more target assemblies