published_or_final_version / Public Health / Master / Master of Public Health

D. Litt et Phil. / It is well known that high levels of anxiety and/or depression often accompany the diagnosis and treatment of cancer. Literature from various sources, but in particular from the fairly new field of research, Psychoneuroimmunology, also provides ample evidence that excessive anxiety and/or depression can be immunosuppressive. It makes sense, therefore, that any intervention restoring balance to the immuno-regulatory system, thereby allowing the body’s innate healing processes to focus on eliminating cancer, is highly desirable. In line with current thinking based on the mind-body connection as well as cognitive behavioural techniques utilised in many therapeutic settings, various psychological interventions have been found to help the patient gain a better sense of control over distressing symptoms and side-effects of cancer. Some of these include: basic cognitive restructuring, hypnotherapy, relaxation-meditation techniques, art and music therapy, and guided imagery. Substantial international research illustrates the beneficial effect that relaxation and/or guided imagery provides in such diverse settings including work, sport and health. In this regard, it was decided to run a pilot study to ascertain whether a customised tape recording with a relaxation and guided imagery dialogue aimed at helping patients manage and cope with negative symptoms of cancer, could significantly reduce anxiety levels in patients with cancer receiving radiotherapy. To operationalise the above, 30 men and women, aged between 20 and 80, with Stages 1, 2 or 3 breast, prostrate, gynaecological cancers, and head and neck cancers, who were about to commence radical (minimum 25 fractions) radiotherapy, were randomly selected to an experimental and a control group. A consecutive sample, pre-test post-test experimental design was applied to this study in which the experimental and control groups were subjected to pre- and post radiotherapy Hospital Anxiety & Depression (HAD) Scale, Institute for Personality Assessment and Training (IPAT) Anxiety Scale and blood pressure measurements during their 1st, 3rd, 6th week cycle of treatments, as well as a final measurement 12 weeks after commencement of therapy. The main hypothesis of this pilot study was that there would be statistically significant decreases in levels of anxiety as a result of the intervention of guided imagery tape recording in patients with non-metastatic cancer undergoing curative radiotherapy. For the intervention, each experimental participant was taught a relaxation technique and then following an interview a customised guided imagery dialogue developed for the participant’s sole use. The participant was requested to listen to this tape at least once a day. The control group had the same pre- and post tests as the experimental group, but did not receive any intervention. Statistical analysis of the data revealed that the experimental group showed a tendency towards decreased blood pressure and anxiety over the course of radiotherapy. The most significant change, however, was noted in terms of diastolic blood pressure, suggesting that the intervention corresponded to a physiological decrease in anxiety. There was not a statistically significant difference in terms of the measured psychological variables. A general conclusion to this pilot study suggests that whilst guided imagery may contribute to a lowering of anxiety, additional cognitive intervention would probably affect a more substantial and sustained change in the patient. Although this pilot study revealed some methodological weaknesses the results are sufficiently encouraging to warrant further in-depth research regarding the use of guided imagery as a cost-effective, easy method for individuals to learn and utilise as part of their integrative cancer treatment programme.

Bibliography: leaves 241-250. A multileaf collimator for radiation therapy has been designed that splits each leaf bank into two vertically displaced assemblies or levels with each level consisting of alternate leaves and leaf spaces. The radiation profiles transmitted for image formation through the collimator design were investigated to examine their dependence on the collimator design features.

The measurement of productivity in health care is difficult. Studies in various specialty disciplines of medicine have identified that the variation in complexities (casemix) between departments or hospitals will vary and therefore will affect any basic productivity statistics that are produced. Radiation oncology is a discipline of medicine where no such studies into radiotherapy casemix variations and the effect that these may have on productivity measures have been performed, despite the high capital expenditure involved in the delivery of radiotherapy. Radiation oncology productivity on linear accelerators is currently measured by the number of patients treated or number of treatment fields treated per unit time (usually per hour). These statistics have been collected for many years and productivity assessments were made on the variations in these statistics that exist between departments. However, these statistics do not consider the variations in casemix that occur between departments. These complexity differences may be quite marked and therefore may strongly influence the ability of a department to achieve a high patient or treatment field throughput. This may be seen as 'reduced productivity' with no consideration of the complexity of the caseload seen in the department. In addition, future technological changes that improve patient outcome may be introduced. These changes may make treatment more complex. Using older measures of productivity such as fields per hour or patients per hour will not consider these technological changes and the subsequent changes in complexity and hence departments may be seen as less productive in the future using current methods of analysis unless a more valid measure of productivity that considers complexity variations is introduced. There have only been 3 previous attempts at developing measures of linear accelerator productivity. Each of these models have been developed empirically and have not been clinically validated. No previous attempts have been made in determining a scientifically-derived complexity model that considers the variations in treatment technique. This thesis describes research performed between 1995 and 2001. This research study???s primary aims were to study the factors that affect radiotherapy treatment time and treatment complexity and to develop a model of linear accelerator productivity that does consider complexity variations in radiotherapy treatment delivery. This model is called the Basic Treatment Equivalent (B.T.E.). This series of trials examines the old models of linear accelerator productivity, describes the derivation and validation of the BTE model both in Australasia and the United Kingdom, identifies the factors that contribute to treatment time and treatment complexity, describes the development of a pilot model of productivity of gynaecological brachytherapy and outpatient chemotherapy using similar BTE methodology, discusses the potential uses of the BTE model, recent independent reviews of BTE by other groups, and the advantages and disadvantages of using such a model. This research has shown that it is possible to identify the various factors that contribute to treatment time and treatment complexity and to derive a model of linear accelerator productivity that considers the variations in complexity. The BTE model has been clinically validated in Australia, New Zealand and a couple of departments in the United Kingdom and Canada and has been adopted as a new measure by various groups. It requires regular updating to maintain currency particularly as there are frequent improvements in radiation treatment technology. Future studies should identify the differences these technological enhancements make to productivity. The BTE derived from outpatient chemotherapy delivery and gynaecological brachytherapy delivery shows promise although these models require further research with the assistance of other departments.

published_or_final_version / Nursing Studies / Master / Master of Nursing in Advanced Practice

published_or_final_version / Surgery / Master / Master of Surgery

No description available.

No description available.

The linear attenuation coefficient and buildup factor are a few of the important characteristics that need to be studied and determined prior to using a material clinically in radiation treatment and protection. The linear attenuation coefficient and buildup factor, as well as several other properties, will be determined for MCP-96 alloy to assess its use in radiation therapy. A narrow collimated beam of γ-rays from sources with varying energies will pass through various thicknesses of MCP-96 alloy. The attenuation in the intensity of the beam will be determined for each varying thickness of the alloy. Plotting the thickness of the alloy versus the corresponding logarithmic intensity of the beam will allow calculation of the linear attenuation coefficient. The narrow beam geometry will then be replaced by the broad beam geometry to determine the buildup factor. Additional radiation is obtained through the broad beam geometry as a result of scattering and secondary radiation. Comparing the broad beam geometry to the narrow beam geometry allows determination of the buildup factor. Since the buildup factor depends upon the thickness of the MCP-96 attenuator, the energy of the beam, and the source-to-attenuator (STA) distance, it will be calculated using three parameters. It will be calculated as a function of thickness of MCP-96 alloy by using various thicknesses of the alloy; as a function of the energy of the incident radiation beam by using several sources with different beam energies; and finally, as a function of the source-to-attenuator distance by changing the position of the MCP-96 attenuators. / Department of Physics and Astronomy

The measurement of productivity in health care is difficult. Studies in various specialty disciplines of medicine have identified that the variation in complexities (casemix) between departments or hospitals will vary and therefore will affect any basic productivity statistics that are produced. Radiation oncology is a discipline of medicine where no such studies into radiotherapy casemix variations and the effect that these may have on productivity measures have been performed, despite the high capital expenditure involved in the delivery of radiotherapy. Radiation oncology productivity on linear accelerators is currently measured by the number of patients treated or number of treatment fields treated per unit time (usually per hour). These statistics have been collected for many years and productivity assessments were made on the variations in these statistics that exist between departments. However, these statistics do not consider the variations in casemix that occur between departments. These complexity differences may be quite marked and therefore may strongly influence the ability of a department to achieve a high patient or treatment field throughput. This may be seen as 'reduced productivity' with no consideration of the complexity of the caseload seen in the department. In addition, future technological changes that improve patient outcome may be introduced. These changes may make treatment more complex. Using older measures of productivity such as fields per hour or patients per hour will not consider these technological changes and the subsequent changes in complexity and hence departments may be seen as less productive in the future using current methods of analysis unless a more valid measure of productivity that considers complexity variations is introduced. There have only been 3 previous attempts at developing measures of linear accelerator productivity. Each of these models have been developed empirically and have not been clinically validated. No previous attempts have been made in determining a scientifically-derived complexity model that considers the variations in treatment technique. This thesis describes research performed between 1995 and 2001. This research study???s primary aims were to study the factors that affect radiotherapy treatment time and treatment complexity and to develop a model of linear accelerator productivity that does consider complexity variations in radiotherapy treatment delivery. This model is called the Basic Treatment Equivalent (B.T.E.). This series of trials examines the old models of linear accelerator productivity, describes the derivation and validation of the BTE model both in Australasia and the United Kingdom, identifies the factors that contribute to treatment time and treatment complexity, describes the development of a pilot model of productivity of gynaecological brachytherapy and outpatient chemotherapy using similar BTE methodology, discusses the potential uses of the BTE model, recent independent reviews of BTE by other groups, and the advantages and disadvantages of using such a model. This research has shown that it is possible to identify the various factors that contribute to treatment time and treatment complexity and to derive a model of linear accelerator productivity that considers the variations in complexity. The BTE model has been clinically validated in Australia, New Zealand and a couple of departments in the United Kingdom and Canada and has been adopted as a new measure by various groups. It requires regular updating to maintain currency particularly as there are frequent improvements in radiation treatment technology. Future studies should identify the differences these technological enhancements make to productivity. The BTE derived from outpatient chemotherapy delivery and gynaecological brachytherapy delivery shows promise although these models require further research with the assistance of other departments.