Radiation therapists' and radiation oncology medical physicists' perceptions of work and the working environment in Australia: a qualitative study.

Workforce recruitment and retention are issues in radiation oncology. The working environment is likely to have an impact on retention; however, there is a lack of research in this area. The objectives of this study were to: investigate radiation therapists' (RTs) and radiation oncology medical physicists' (ROMPs) perceptions of work and the working environment; and determine the factors that influence the ability of RTs and ROMPs to undertake their work and how these factors affect recruitment and retention. Semi-structured interviews were conducted and thematic analysis was used. Twenty-eight RTs and 21 ROMPs participated. The overarching themes were delivering care, support in work, working conditions and lifestyle. The overarching themes were mostly consistent across both groups; however, the exemplars reflected the different roles and perspectives of RTs and ROMPs. Participants described the importance they placed on treating patients and improving their lives. Working conditions were sometimes difficult with participants reporting pressure at work, large workloads and longer hours and overtime. Insufficient staff numbers impacted on the effectiveness of staff, the working environment and intentions to stay. Staff satisfaction is likely to be improved if changes are made to the working environment. We make recommendations that may assist departments to support RTs and ROMPs.

Utilitarian prioritization of radiation oncology patients based on maximization of population tumour control.

An objective method for establishing patient prioritization in the context of a radiotherapy waiting list is investigated. This is based on a utilitarian objective, being the greatest probability of local tumour control in the population of patients. A numerical simulation is developed and a clinical patient case-mix is used to determine the influence of the characteristics of the patient population on resulting optimal patient scheduling. With the utilitarian objective, large gains in tumour control probability (TCP) can be achieved for individuals or cohorts by prioritizing patients for that fraction of the patient population with relatively small sacrifices in TCP for a smaller fraction of the population. For a waiting list in steady state with five patients per day commencing treatment and leaving the list (and so with five patients per day entering the list), and a mean wait time of 35 days and a maximum of 90 days, optimized wait times ranged from a mean of one day for patients with tumour types with short effective doubling times to a mean of 66.9 days for prostate cancer patients. It is found that, when seeking the optimal daily order of patients on the waiting list in a constrained simulation, the relative rather than absolute value of TCP is the determinant of the resulting optimal waiting times. An increase in the mean waiting time mostly influences (increases) the optimal waiting times of patients with fast-growing tumours. The proportional representation of groups (separated by tumour type) in the patient population has an influence on the resulting distribution of optimal waiting times for patients in those groups, though has only a minor influence on the optimal mean waiting time for each group.

Comparison of DVH data from multiple radiotherapy treatment planning systems.

This study examined the variation of dose-volume histogram (DVH) data sourced from multiple radiotherapy treatment planning systems (TPSs). Treatment plan exports were obtained from 33 Australian and New Zealand centres during a dosimetry study. Plan information, including DVH data, was exported from the TPS at each centre and reviewed in a digital review system (SWAN). The review system was then used to produce an independent calculation of DVH information for each delineated structure. The relationships between DVHs extracted from each TPS and independently calculated were examined, particularly in terms of the influence of CT scan slice and pixel widths, the resolution of dose calculation grids and the TPS manufacturer. Calculation of total volume and DVH data was consistent between SWAN and each TPS, with the small discrepancies found tending to increase with decreasing structure size. This was significantly influenced by the TPS model used to derive the data. For target structures covered with relatively uniform dose distributions, there was a significant difference between the minimum dose in each TPS-exported DVH and that calculated independently.

Acute radiation toxicity assessment of a 3-D conformal head and neck radiation treatment technique.

Patients undergoing radiation treatment for head and neck cancer have many critical structures within or adjacent to the treatment area. Avoiding these critical structures is more efficient and easier using 3-D conformal planning. At Sir Charles Gairdner Hospital an investigation into the acute radiation toxicity was undertaken when the head and neck treatment technique was changed from the conventional 2-D plan to the conformal 3-D plan. Although the primary target volume (PTV), fraction size and overall dose remain the same for the two techniques, differing beam configurations mean that treatment fields enter and exit through different parts of the head and neck. Ten patients were initially assessed to gain a baseline appearance of their head and neck region, and then graded weekly according to the toxicity criteria during treatment and at 4, 8 and 12 weeks after treatment. The results of the assessment indicate that there is no increase in toxicity as a result of treating using the conformal head and neck technique.