ACPSEM position paper on ROMP scope of practice and staffing levels for magnetic resonance linear accelerators.

The purpose of this position paper is to outline the ACPSEM recommendations on Medical Physicist scope of practice and staffing levels, as they relate to the use of dedicated MRI-Linacs in the treatment of patients. A core function of Medical Physicists is to safely implement changes in medical practice via the introduction of new technology and to ensure high quality radiation oncology services are provided to patients. Determining the feasibility of MRI-Linacs in any existing setting, or in establishing a new site, mandates the knowledge and services of Radiation Oncology Medical Physicists (ROMPs) as the Qualified Experts within this setting. ROMPs are key members of the multi-disciplinary team which will be required to steer the successful establishment of MRI Linac infrastructure within departments. To support efficient implementation, ROMPs must be embedded in the process from the start, including any feasibility study, initiation of the project, and development of the business case. ROMPs must be retained throughout all stages of acquisition, service development, and ongoing clinical use and expansion. The number of MRI-Linacs in Australia and New Zealand is growing. This expansion is occurring in parallel with rapid technological evolution, expanding tumour stream applications, and increasing consumer uptake. Growth and applications of MRI-Linac therapy will continue to occur beyond current known horizons, via development on the MR-Linac platform itself and through the migration of learning from this platform to conventional Linacs (known horizons for example include the use of daily, online image guided adaptive radiotherapy and MRI data informing decision making for planning and treatment before and throughout treatment courses). Clinical use, research and development will be a significant component of expanding patient access to MRI-Linac treatment and there will be an ongoing need to attract and retain ROMPs to initially establish services and in particular to drive service development and delivery for the life of the Linacs. MRI and Linac technologies mean it is necessary to perform a specialized workforce assessment for these devices, distinct from those employed for conventional Linacs and associated services. MRI-Linacs are complex, have a heightened risk profile compared to standard Linacs, and are unique in their treatment of patients. Accordingly, the workforce needs for MRI-Linacs are greater than for standard Linacs. To ensure safe and high-quality Radiation Oncology patient services are provided, it is recommended that staffing levels should be based on the 2021 ACPSEM Australian Radiation Workforce model and calculator using the MRI-Linac specific ROMP workforce modelling guidelines outlined in this paper. The ACPSEM workforce model and calculator are closely aligned with other Australian/New Zealand and international benchmarks.

Victoria (Australia) radiotherapy response to working through the first and second wave of COVID-19: Strategies and staffing.

INTRODUCTION: The COVID-19 pandemic demanded a rapid response within Radiation Oncology services to minimise the risk of infection to patients and workforce. This study aimed to assess whether the operational changes put in place to reduce infection risks were effective in engaging and supporting staff. METHODS: Our service's response saw staff and patients split into morning or afternoon shifts without overlap. Changes included extended clinic hours, modified treatment regimens, expanded online/electronic communication and remote working. Staff were invited to respond to an electronic questionnaire in September 2020, just after the peak of the second COVID-19 wave in Victoria. Responses captured demographic data, parental status, profession, happiness levels, fear of COVID-19 and e-communication efficacy. RESULTS: A 57% response rate was achieved. 69% of respondents were female; 40% were aged 45+ and 35% had school-aged children. Staff aged 45+ showed a significantly greater fear of COVID-19 than younger staff. 36% of respondents reported feeling nervous or anxious watching news reports about COVID-19. 92% of staff were happy with their work arrangements; staff with children were happier than staff without children with their shifts. Online chat/channels were reported as the preferred e-communication method between colleagues. CONCLUSION: Staff provided predominantly positive feedback to the changes made in response to the pandemic, reporting high levels of happiness and willingness to continue with the changes implemented during COVID-19. The strategies adopted worked well and the overall high levels of staff satisfaction will allow our service to quickly pivot should further surges, or another pandemic, arise.

A phantom study to contrast and compare polymer and gold fiducial markers in radiotherapy simulation imaging.

To assess visibility and artifact characteristics of polymer fiducials compared to standard gold fiducials for radiotherapy CT and MRI simulation. Three gold and three polymer fiducials were inserted into a CT and MRI tissue-equivalent phantom that approximated the prostate cancer radiotherapy configuration. The phantom and fiducials were imaged on CT and MRI. Images were assessed in terms of fiducial visibility and artifact. ImageJ was employed to quantify the pixel gray-scale of each fiducial and artifact. Fiducial gray-scale histograms and profiles were generated for analysis. Objective measurements of the contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and artifact index (AI) were calculated. The CT images showed that the gold fiducials are visually brighter, with greater contrast than the polymer. The higher peak values illustrate this in the line profiles. However, they produce bright radiating and dark shadowing artifacts. This is depicted by the greater width of line profiles and the disruption of phantom area profiles. Quantitatively this results in greater percentile ranges of the histograms. Furthermore, for CT, gold had a higher CNR than polymer, relative to the phantom. However, the gold CNR and SNR were degraded by the greater artifact and thus AI. Both fiducials were visible on MRI and had similar histograms and profiles that were also reflected in comparable CNR, SNR and AI. Polymer fiducials were well visualized in a phantom on CT and MR and produce less artifact than the gold fiducials. Polymer markers could enhance the quality and accuracy of radiotherapy co-registration and planning but require clinical confirmation.

Assessing the impact of FDG-PET in the management of anal cancer.

PURPOSE: To assess the utility of FDG-PET in anal cancer for staging and impact on radiotherapy planning (RTP), response and detection of recurrent disease. METHODS AND MATERIALS: Fifty histopathological anal cancer patients were reviewed between 1996 and 2006. The median age was 58 years (range 36-85) with 19 males:31females. Clinical assessment with CT was compared to PET. Impact on management, disease response, recurrence and metastases was evaluated. RESULTS: The non-PET staging was Stage I(8), Stage II(18), Stage III(22), and Stage IV(2)s. The primary was strongly FDG avid in 98% with non-excised tumors compared to CT (58%). PET upstaged 17% with unsuspected pelvic/inguinal nodal disease. Pre-treatment PET identified 11 additional by involved nodal groups in 48 patients causing RTP amendments in 19%. Post-treatment PETs at median 17 weeks (range 9-28) showed complete responses in 20 (80%) and 5 (20%) partial responses (PR). PRs were biopsy positive in 2 and negative in 3. Fifteen had follow-up scans of which all nine PETs detected recurrences were pathologically confirmed. CONCLUSIONS: Anal cancer is FDG-PET avid. PET upstages 17% and changes the RTP in 19%. PET can aid in anal cancer staging and identification of residual disease, recurrent/metastatic disease but warrants further prospective studies.

Orbital lymphoma: a simple treatment using electrons.

Previous papers have discussed the successful treatment of orbital lymphoid tumors using a low-vacuum contact lens placed directly on the eye and the use of a lead bar suspended over the eye with a retort stand. In this paper, a novel approach using a cerrobend bar attached to an electron shield for the treatment of a conjunctival lymphoma is presented. With this approach, the entire eye, excluding the lens, may be treated with a single field. Isodose distributions measured in a water phantom are compared with those planned on a 3D radiotherapy treatment planning system, where the effects of an external eye bar can be shown. The clinical outcome of the treatment is also shown.