ABSTRACT
The use of dedicated PET scanners is becoming more widespread throughout Australia and the world. PET imaging utilizes short-lived (approximately 108 min), high-energy (511 keV) gamma-ray emitters that could result in a high radiation dose being received by staff. As part of a larger staff and area monitoring project, this paper discusses the personal dose equivalent, H(p)(10), received by PET staff working in a dedicated PET center. The typical H(p)(10) received by staff was approximately 1 microSv per minute of close contact with patients, which resulted in an average daily dose for nuclear medicine technologists of approximately 31 microSv. The average daily administered activity to patients at Austin Health was 1,280 MBq.
Subject(s)
Positron-Emission Tomography/methods , Radiometry/standards , Humans , Occupational Exposure/statistics & numerical data , Positron-Emission Tomography/standards , Radiation Dosage , Radiometry/methods , Thermoluminescent DosimetryABSTRACT
Interventional radiological procedures have significantly increased the probability for the expression of deterministic detriment to the patient. It is the responsibility of the consulting medical physicist to undertake the responsibility that (i) appropriate equipment is specified and purchased; (ii) the equipment purchased produces the best possible image quality for the minimum dose; (iii) accurate dosimetry is measured, calculated and recorded; (iv) interventional physicians and surgeons are adequately trained in the fundamental techniques that will minimize the dose to both patients and staff, while maintaining high image quality; and (v) interventional protocols, record keeping and patient follow-up, in the case of deterministic doses, are appropriately implemented.
Subject(s)
Health Physics/organization & administration , Quality Assurance, Health Care , Radiology, Interventional , Humans , Patient Care Team , Radiology, Interventional/education , Radiology, Interventional/instrumentation , Radiology, Interventional/standards , RoleABSTRACT
A suggested protocol for the in-air calibration of 192Ir High Dose Rate (HDR) Brachytherapy sources is presented. The protocol was constructed using Nucletron-Oldelft HDR brachytherapy equipment and should be transportable to any High Dose Rate Brachytherapy Afterloader system.
Subject(s)
Brachytherapy/instrumentation , Iridium Radioisotopes/therapeutic use , CalibrationABSTRACT
Proposed methods for the initial source installation tests, acceptance testing and a continuing quality assurance program are presented for a Nucletron-Odelft High Dose-Rate Brachytherapy Afterloader system.
Subject(s)
Brachytherapy/instrumentation , Iridium Radioisotopes/therapeutic use , Quality Assurance, Health Care , Brachytherapy/standards , Radiotherapy DosageABSTRACT
A physical map of the chromosome of N. meningitidis Z2491 (serogroup A, subgroup IV-1) has been constructed. Z2491 DNA was digested with NheI, SpeI, SgfI, PacI, BglII, or PmeI, resulting in a limited number of fragments that were resolved by contour-clamped homogeneous electric field (CHEF) electrophoresis. The estimated genome size for this strain was 2,226 kb. To construct the map, probes corresponding to single-copy genes or sequences were used on Southern blots of chromosomal DNA digested with the different mapping enzymes and subjected to CHEF electrophoresis. By determining which fragments from different digests hybridized to each specific probe, it was possible to walk back and forth between digests to form a circular macrorestriction map. The intervals between mapped restriction sites range from 10 to 143 kb in size. A total of 117 markers have been placed on the map; 75 represent identified genes, with the remaining markers defined by anonymous cloned fragments of neisserial DNA. Comparison of the arrangement of genetic loci in Z2491 with that in gonococcal strain FA1090, for which a physical map was previously constructed, revealed complex genomic rearrangements between the two strains. Although gene order is generally conserved over much of the chromosome, a region of approximately 500 kb shows translocation and/or inversion of multiple blocks of markers between the two strains. Even within the relatively conserved portions of the maps, several genetic markers are in different positions in Z2491 and FA1090.
Subject(s)
Chromosomes, Bacterial , Gene Rearrangement , Neisseria gonorrhoeae/genetics , Neisseria meningitidis/genetics , Restriction Mapping , Base Sequence , Chromosome Inversion , Chromosome Walking/methods , DNA Probes , Deoxyribonucleases, Type II Site-Specific , Electrophoresis, Gel, Pulsed-Field , Genetic Markers , Molecular Sequence Data , Translocation, GeneticABSTRACT
The Radiotherapy Department at Heidelberg Repatriation Hospital has purchased the first Digital Portal Imaging System (DPIS) in Australia. The DPIS has a demountable armature attached to a Philips SL15 6MV X-ray therapy unit. The SRI-100 captures' images which can then be printed, stored or processed for image enhancement. The component sections of the DPIS are image detection, conversion, processing, control and display. All sections are made up from original equipment manufacturer modules that should provide for ease of access to spare parts and technical support. Computer control is provided from a Compaq 386-SX PC using DOS version 3.3 and a GEM desktop environment. The imaging software is user friendly and provides the operator with a comparatively easy environment in which to write dedicated image processing procedures as the need arises. The standard software provides a large number of image processing routines including filters, statistical functions, grey-scale manipulation and image housekeeping. A daily QA program has been implemented using system software to check camera noise and image saturation, with a monthly imaging QA program using the RMI Portal Film Phantom. The systems strengths and weaknesses are discussed along with suggested hardware and software improvements and upgrades.
Subject(s)
Radiographic Image Enhancement , Radiotherapy Planning, Computer-Assisted , Australia , Equipment Design , Models, Structural , Quality Assurance, Health Care , Radiographic Image Enhancement/instrumentation , Radiographic Image Enhancement/standards , Radiotherapy Planning, Computer-Assisted/instrumentation , Radiotherapy Planning, Computer-Assisted/standards , Radiotherapy, High-Energy , Software , X-Ray FilmABSTRACT
A 69 year old male was treated with an ablative dose of 3.7 GBq (100 mCi) of I131 for carcinoma of the thyroid and died 10 days after administration. The requirement for an autopsy and the level of radiation still present in the body necessitated the intervention of Radiation Safety Personnel to minimise support staff radiation exposure and area contamination. Preventative measures were taken in accordance with the ALARA principle and a detailed procedure is presented as a suggested model for any future occurrence.
