Health and Lifestyle Factors of Australian Medical Radiation Workers: A Pilot Study Using Nuclear Medicine Technologists.

The health effects of chronic low-dose radiation exposure are a subject of worldwide debate. These effects are difficult to assess because all low-dose exposure mechanisms must be accounted for, including background exposure, personal medical examinations, and environmental exposure such as aviation, as well as lifestyle choices contributing to disease. The current literature recommends investigation of lifestyle factors to fill in these gaps. The aim of this study was to pilot-test a survey developed to assess health and lifestyle factors for Australian medical radiation workers. Methods: A cohort of nuclear medicine technologists (NMTs) was selected to test the survey. The survey consisted of 53 questions relating to demographics, employment, lifestyle, and health. Data from the 2017-2018 Australian National Health Survey were used to compare the lifestyle choices and health of the participants with those of the Australian general population. Results: In total, 101 participants pilot-tested the survey. Overall, Australian NMTs make better lifestyle choices (more exercise, more vegetable intake, lower rates of smoking and alcohol consumption) resulting in lower rates of obesity than the Australian general population. NMTs had a higher reported health status than the Australian population, with lower levels of psychologic distress. Given the low age of NMTs participating in the study, the cancer incidence rate may be higher than that reported for the Australian general population; however, a larger sample size is required to provide more definitive results. Conclusion: This pilot study demonstrated the feasibility of conducting a widespread survey to assess health and lifestyle factors for the Australian medical radiation worker cohort. Comparison of survey results with data for the entire Australian population have highlighted the potential to increase the number of lifestyle questions.

Development of consensus statements for pregnancy screening in diagnostic nuclear medicine: a Delphi study.

UNLABELLED: Current radiation protection recommendations do not provide clear guidelines or advice on pregnancy screening strategies for diagnostic nuclear medicine procedures. Previous studies have reported on variations in current practice for pregnancy screening before diagnostic nuclear medicine procedures. The development of consensus statements aims to provide a consistent approach and assist nuclear medicine personnel to confidently question patients about their pregnancy status. METHODS: The Delphi technique was chosen for the research design. A panel consisting of 10 experienced nuclear medicine personnel from Australia and New Zealand was recruited. Panel members were provided with a summary of existing research. Consensus agreement was predefined as 80%. Questionnaires were developed and distributed to the panel members, with iterative analysis and feedback between survey rounds. Three survey rounds were conducted online using SurveyMonkey between December 2013 and June 2014. The round 1 questionnaire was developed from the results of a previous survey. It consisted of 30 questions designed to gather the opinions of the expert panel. After analysis of the round 1 responses, consensus statements were developed for round 2 and revised in round 3. RESULTS: Consensus was achieved for 16 statements. The statements recommend using verbal questioning with patient signature, defining the age range for questioning as 12-55 y, providing advice on the use of pregnancy testing, and questioning potentially difficult groups such as teenagers. A flowchart was included for comment in round 3. CONCLUSION: This was the first Australian study to develop consensus statements and a flowchart to assist nuclear medicine personnel in consistently and confidently questioning patients about their pregnancy status before diagnostic procedures. Implementation of these statements into clinical practice guidelines should reduce the possibility of inadvertent fetal irradiation.

Comparing four volumetric modulated arc therapy beam arrangements for the treatment of early-stage prostate cancer.

INTRODUCTION: This study compared four different volumetric modulated arc therapy (VMAT) beam arrangements for the treatment of early-stage prostate cancer examining plan quality and the impact on a radiotherapy department's resources. METHODS: Twenty prostate cases were retrospectively planned using four VMAT beam arrangements (1) a partial arc (PA), (2) one arc (1A), (3) one arc plus a partial arc (1A + PA) and (4) two arcs (2A). The quality of the dose distributions generated were compared by examining the overall plan quality, the homogeneity and conformity to the planning target volume (PTV), the number of monitor units and the dose delivered to the organs at risk. Departmental resources were considered by recording the planning time and beam delivery time. RESULTS: Each technique produced a plan of similar quality that was considered adequate for treatment; though some differences were noted. The 1A, 1A + PA and 2A plans demonstrated a better conformity to the PTV which correlated to improved sparing of the rectum in the 60-70 Gy range for the 1A + PA and 2A techniques. The time needed to generate the plans was different for each technique ranging from 13.1 min for 1A + PA to 17.8 min for 1A. The PA beam delivery time was fastest with a mean time of 0.9 min. Beam-on times then increased with an increase in the number of arcs up to an average of 2.2 min for the 2A technique. CONCLUSION: Which VMAT technique is best suited for clinical implementation for the treatment of prostate cancer may be dictated by the individual patient and the availability of departmental resources.

The quality assurance of volumetric modulated arc therapy (VMAT) plans for early stage prostate cancer: a technical note.

As radiation therapy transitions from intensity modulated radiation therapy (IMRT) to volumetric modulated arc therapy (VMAT) it is important to consider the quality assurance (QA) of VMAT plans in light of what has previously been learned and developed in IMRT QA. This technical note assesses if IMRT based plan QA software, which has reduced the need in IMRT for phantom dose measurements on the linear accelerator, can be incorporated into VMAT QA processes. Twenty prostate cases were retrospectively planned using VMAT with one arc to deliver a prescription of 74 Gy in 37 fractions. A plan QA was performed using both IMSure (version 3.3), a software-based IMRT QA program, and ArcCHECK (version 6.2.3.5713), a phantom-based VMAT QA tool. Outcomes assessed included the time needed to perform the QA of both the IMSure and ArcCHECK QA methods, and agreement between planned dose and QA measured dose. On average per case, the ArcCHECK technique needed 31.5 min to perform the VMAT plan QA, while IMSure required 3.5 min to perform the same QA. All 20 cases passed dosimetric QA using ArcCHECK. However, using IMSure, three cases failed dosimetric QA using the departments existing IMRT QA criteria. This research has demonstrated that the IMRT QA software IMSure may be incorporated into the QA of VMAT plans, however the criteria to assess the dosimetry of the VMAT plans may need to be different to that for IMRT cases. The implication of this research for radiation therapists is to be critically aware of the differences between the plan QA requirements and methods for IMRT and those required for VMAT.

Pregnancy screening strategies for potentially challenging patients before diagnostic nuclear medicine procedures: qualitative survey analysis.

UNLABELLED: Because of the ionizing radiation used in diagnostic nuclear medicine procedures, it is recommended that all female patients of childbearing age be questioned about their pregnancy status before the procedure begins. Several patient groups have been identified as potentially difficult to question: teenagers, unconscious or sedated patients, patients with language or cultural barriers, and patients with mental disability. Our aim was to capture the thoughts and opinions of nuclear medicine personnel in Australia and New Zealand regarding pregnancy screening strategies before diagnostic imaging procedures. METHODS: Members of the Australian and New Zealand Society of Nuclear Medicine were invited to complete an online survey. Section 4 consisted of open-response questions asking participants to describe the strategies they use to question a patient about pregnancy status in 4 potentially difficult clinical scenarios. The content of the responses was analyzed. RESULTS: For each question, 232 responses were recorded. The most commonly used strategies included questioning teenage girls away from their parents, referring to medical notes for unconscious patients, using an interpreter and visual aids for patients with language barriers, and asking a caregiver or relative of mentally disabled patients. Pregnancy testing was used when there was doubt about the patient's pregnancy status. Personal questions about menstrual and sexual history were often asked to determine the risk of pregnancy. CONCLUSION: The study revealed that a variety of strategies are used by nuclear medicine personnel in Australia and New Zealand to determine the pregnancy status of patients. A standardized practice guideline may be useful to ensure a consistent approach to questioning that would optimize the accuracy of pregnancy assessment and reduce the possibility of fetal irradiation.

Pregnancy screening strategies for diagnostic nuclear medicine: survey results from Australia and New Zealand.

UNLABELLED: The ionizing radiation used in diagnostic nuclear medicine procedures has the potential to cause biologic harm to a fetus. Although the risks are relatively small, it is recommended that all female patients of childbearing age be questioned regarding their pregnancy status before administration of the radiopharmaceutical. This can be a sensitive situation especially for certain types of patients, such as teenagers. Currently, there are no guidelines that detail how to question the patient. Previous studies have revealed the lack of a consistent approach in this area. The aim of this study was to investigate current practice for pregnancy screening before diagnostic nuclear medicine procedures in Australia and New Zealand and to determine whether a standardized practice guideline is required. METHODS: An online survey was administered via SurveyMonkey from October to December 2011. Members of the Australian and New Zealand Society of Nuclear Medicine were invited to participate. The survey consisted of 30 questions divided into 4 sections: demographics, policy and regulations, current practice, and open-ended clinical scenarios. RESULTS: Three hundred thirty-five responses were recorded from participants in all states and territories of Australia and New Zealand; 90% were nuclear medicine technologists. Participants reported a low awareness of radiation policy and regulations but demonstrated good knowledge of the relative risk to the fetus from commonly performed procedures. The most common minimum and maximum age to question patients was 12 y (32%) and 55 y (42%), respectively, although the range was from 10 to 60 y. Verbal questioning (44%) was the most commonly used approach. Pregnancy testing was used by 72%, usually if the patient indicated she was unsure of her pregnancy status. Responses to clinical scenarios were varied, and these will be discussed in a subsequent paper. CONCLUSION: The survey revealed a lack of awareness of government regulations and departmental policy regarding radiation protection. The study demonstrated wide variety in pregnancy screening strategies used to determine the pregnancy status of patients before diagnostic nuclear medicine procedures, indicating that a standardized practice guideline is required for Australia and New Zealand.

A retrospective planning analysis comparing intensity modulated radiation therapy (IMRT) to volumetric modulated arc therapy (VMAT) using two optimization algorithms for the treatment of early-stage prostate cancer.

INTRODUCTION: The primary aim of this study is to compare intensity modulated radiation therapy (IMRT) to volumetric modulated arc therapy (VMAT) for the radical treatment of prostate cancer using version 10.0 (v10.0) of Varian Medical Systems, RapidArc radiation oncology system. Particular focus was placed on plan quality and the implications on departmental resources. The secondary objective was to compare the results in v10.0 to the preceding version 8.6 (v8.6). METHODS: Twenty prostate cancer cases were retrospectively planned using v10.0 of Varian's Eclipse and RapidArc software. Three planning techniques were performed: a 5-field IMRT, VMAT using one arc (VMAT-1A), and VMAT with two arcs (VMAT-2A). Plan quality was assessed by examining homogeneity, conformity, the number of monitor units (MUs) utilized, and dose to the organs at risk (OAR). Resource implications were assessed by examining planning and treatment times. The results obtained using v10.0 were also compared to those previously reported by our group for v8.6. RESULTS: In v10.0, each technique was able to produce a dose distribution that achieved the departmental planning guidelines. The IMRT plans were produced faster than VMAT plans and displayed improved homogeneity. The VMAT plans provided better conformity to the target volume, improved dose to the OAR, and required fewer MUs. Treatments using VMAT-1A were significantly faster than both IMRT and VMAT-2A. Comparison between versions 8.6 and 10.0 revealed that in the newer version, VMAT planning was significantly faster and the quality of the VMAT dose distributions produced were of a better quality. CONCLUSION: VMAT (v10.0) using one or two arcs provides an acceptable alternative to IMRT for the treatment of prostate cancer. VMAT-1A has the greatest impact on reducing treatment time.

Determining the pregnancy status of patients before diagnostic nuclear medicine procedures: the Australian experience.

UNLABELLED: Ionizing radiation used in diagnostic nuclear medicine procedures has the potential to have biologic effects on a fetus. Nuclear medicine technologists (NMTs) therefore have a responsibility to ensure that they question all patients of childbearing age about their pregnancy status before starting any procedure, to avoid unnecessary fetal irradiation. In Australia, there are no clearly defined practice guidelines to assist NMTs in determining whom to question or how to question their patients. METHODS: Semistructured interviews were conducted with chief NMTs and staff NMTs in 8 nuclear medicine departments in Australia. Questions were based around 5 areas: regulations and policy, fetal radiation exposure, questioning of the patient, difficulties in determining pregnancy status, and the impact of the use of hybrid imaging. Audio files of the interviews were transcribed and coded. RESULTS: Topics were coded into 5 themes: policy and awareness of guidelines, questioning the patient, radiation knowledge, decisions and assumptions made by NMTs, and the use of pregnancy testing. There was a wide variation in practice between and within departments. NMTs demonstrated a lack of knowledge and awareness of the possible biologic effects of radiation. CONCLUSION: This study identified a need in Australia for nuclear medicine to arrive at a consensus approach to verifying a patient's pregnancy status so that NMTs can successfully question patients about their pregnancy status. Continuing education programs are also required to keep NMTs up to date in their knowledge.

An Introduction to the Intensity-modulated Radiation Therapy (IMRT) Techniques, Tomotherapy, and VMAT.

The goal of radiation therapy is to administer a therapeutic dose of radiation to a target while limiting the side effects caused by delivering the dose to surrounding tissues and vital organs. The ongoing pursuit to achieve an optimal dose distribution has prompted the radiation therapy profession to develop new techniques that incorporate advances in technology. In radiation therapy today, modern techniques that include three-dimensional conformal radiation therapy (3D-CRT) and intensity-modulated radiation therapy (IMRT) are routinely used in the treatment of cancers. Compared with 3D-CRT, IMRT is capable of producing dose distributions that conform to the planning treatment volume and deliver a reduced dose to surrounding tissues and vital organs. This has come with the cost of increased treatment time and a larger volume of normal tissue receiving low radiation doses. Most recently, there has been considerable interest in the rotating gantry IMRT techniques, tomotherapy and volumetric-modulated arc therapy (VMAT). Tomotherapy is a dedicated treatment system that is best described as a combination of a computed tomography scanner and a linear accelerator. In tomotherapy, treatment is delivered using a rotating fan beam. A therapeutic dose is delivered when a patient is translated smoothly through the bore of the machine as its gantry continuously rotates. Tomotherapy is capable of producing high-quality plans that increasingly spare dose to surrounding organs at risk. In VMAT, treatment is delivered on a linear accelerator using a cone beam that rotates around the patient. The cone beam is modulated by dynamic multileaf collimation, variable dose rate and variable gantry speed to generate IMRT-quality dose distributions in a single optimized arc around the patient. VMAT treatments can significantly reduce the time and monitor units required to deliver a patient's treatment. Conventional IMRT, tomotherapy and VMAT typically produce dose distributions of similar quality. Which technique is most suited to treat a patient will depend on considerations such as the availability of the specific treatment type and its impact on the utilization of departmental planning and treatment resources.