Practice patterns of radiation therapy technology in Australia: results of a national audit

The assessment of the clinical impact of using a single set of radiotherapy planning data for two kilovoltage therapy units

Kilovoltage therapy units are used for superficial radiotherapy treatment delivery. Peer reviewed studies for MV linear accelerators describe tolerances to dosimetrically match multiple linear accelerators enabling patient treatment on any matched machine. There is an absence of literature on using a single planning data set for multiple kilovoltage units which have limited ability for beam adjustment. This study reviewed kilovoltage dosimetry and treatment planning scenarios to evaluate the feasibility of using ACPSEM annual QA tolerances to determine whether two units (of the same make and model) were dosimetrically matched. The dosimetric characteristics, such as measured half value layer (HVL), percentage depth dose (PDD), applicator factor and output variation with stand-off distance for each kV unit were compared to assess the agreement. Independent planning data based on the measured HVL for each beam energy from each kV unit was prepared. Monitor unit (MU) calculations were performed using both sets of planning data for approximately 200 clinical scenarios and compared with an overall agreement between units of < 2%. Additionally, a dosimetry measurement comparison was completed at each site for a subset of nine scenarios. All machine characterisation measurements were within the ACPSEM Annual QA tolerances, and dosimetric testing was within 2.5%. This work demonstrates that using a single set of planning data for two kilovoltage units is feasible, resulting in a clinical impact within published uncertainty.

‘Is the technology essential or emerging?’ Ways to keep radiation therapy curriculum agile amid rapidly advancing technology

Advancing technology in radiation therapy can significantly influence clinical practice and improvement of patient outcomes. In the process, innovations in technology require that changes to clinical practice are adopted within education settings. This commentary aims to describe the uptake of new technology and ways that academics provide an up-to-date curriculum when today's innovation is tomorrow's contemporary practice.

Modelling of a novel technique to improve the visualisation of implanted fiducial markers for intra-fraction MV imaging of prostate VMAT targets

Purpose. This study explored a novel technique to improve the MV imaging based fiducial visibility for a cohort of prostate radiotherapy patients, without compromising the original treatment plan. The study also compared these results to visibility using single MLC control points, as well as short arcs.Methods. Geometric data from 68 prostate radiotherapy treatments, each with implanted gold fiducials, was retrospectively analysed. Fiducials were contoured for each patient, and conventional and SBRT treatment plans were generated using a VMAT technique. Using an in-house script, fiducial contours were projected onto the VMAT MLC control points. Resulting data was assessed to determine whether the fiducial contours were theoretically visible for single MLC control points and groups of MLC control points (short arcs), both being surrogates for intra-fraction MV imaging. Using this data, a theoretical quadrant technique was investigated that assessed the region surrounding each fiducial to determine if visualisation would theoretically improve.Results. Using a conventional treatment type, mean fiducial visibility for single MLC control points across the patient cohort ranged from 2.5% up to 17.8%. For SBRT, fiducial visibility ranged from 1.8% up to 19.7%. For short arcs, fiducial visibility for conventional treatment types ranged from 5.9% up to 20.7%. For SBRT, fiducial visibility ranged from 4.6% up to 23.1%. When the novel fiducial quadrant technique was used, theoretical visibility improved two-fold, from 22.7% up to 52.5% and from 24.7% up to 55.3% for conventional and SBRT treatment types respectively.Conclusions. Fiducial visibility was assessed for a cohort of VMAT prostate patients. Using the novel quadrant technique, it was demonstrated that theoretical visualisation and localisation of the implanted fiducials could be improved two-fold, without sacrificing treatment plan quality.

Implementation of advanced radiotherapy technology to improve clinical outcomes in rural NSW

PROBLEM

Availability of advanced radiotherapy technology to treat cancer is limited in regional Australia. At Central West Cancer Care Centre, the utilisation rate of intensity-modulated radiotherapy and volumetric modulated arc therapy was significantly lower compared to other NSW public health services. Stereotactic ablative body radiotherapy treatment was not available at Central West Cancer Care Centre.

DESIGN

To increase the intensity-modulated radiotherapy/volumetric modulated arc therapy utilisation rate and to make stereotactic ablative body radiotherapy treatment available through quality improvement projects with multi-disciplinary collaboration.

SETTING

Central West Cancer Care Centre is part of Western NSW Local health District. Central West Cancer Care Centre has two linear accelerators for delivering intensity-modulated radiotherapy, volumetric modulated arc therapy and stereotactic ablative body radiotherapy treatments, and a computed tomography simulator with 4D computed tomography capability.

KEY MEASURES FOR IMPROVEMENT

Intensity-modulated radiotherapy/volumetric modulated arc therapy utilisation rate increases to > 65% Stereotactic ablative body radiotherapy available to Central West Cancer Care Centre patients STRATEGY FOR CHANGE: A multi-disciplinary active of team radiation oncologists, medical physics specialists and radiation therapists developed an implementation plan for each treatment technique.

EFFECT OF CHANGE

There was a significant increase in use of advanced techniques. The impact on patients included the following: Fewer side effects and improved control of disease as the advanced techniques directed the dose to the tumour and reduced the radiation dose to organ at risk. Treatment completed sooner than conventional radiotherapy, as the required dose required fewer trips to the hospital. Rural and remote patients were not required to travel to a metropolitan centre to have stereotactic ablative body radiotherapy treatment.

LESSONS LEARNT

Strong commitment from a trained team and a collaborative approach is important for the implementation of advanced technology in regional centres.

Technical note: A modified gamma evaluation method for dose distribution comparisons

Purpose

In this work we have developed a novel method of dose distribution comparison, the inverse gamma (IG) evaluation, by modifying the commonly used gamma evaluation method.

Methods

The IG evaluation calculates the gamma criteria (dose difference criterion, ΔD, or distance‐to‐agreement criterion, Δd) that are needed to achieve a predefined pass rate or gamma agreement index (GAI). In‐house code for evaluating IG with a fixed ΔD of 3% was developed using Python (v3.5.2) and investigated using treatment plans and measurement data from 25 retrospective patient specific quality assurance tests (53 individual arcs).

Results

It was found that when the desired GAI was set to 95%, approximately three quarters of the arcs tested were able to achieve Δd within 1 mm (mean Δd: 0.7 ± 0.5 mm). The mean Δd required in order for all points to pass the gamma evaluation (i.e., GAI = 100%) was 4.5 ± 3.1 mm. The possibility of evaluating IG by fixing the Δd or ΔD/Δd, instead of fixing the ΔD at 3%, was also investigated.

Conclusion

The IG method and its indices have the potential to be implemented clinically to quantify the minimum dose and distance criteria based on a specified GAI. This method provides additional information to augment standard gamma evaluation results during patient specific quality assurance testing of individual treatment plans. The IG method also has the potential to be used in retrospective audits to determine an appropriate set of local gamma criteria and action levels based on a cohort of patient specific quality assurance plans.

Equipment, staffing, and provision of radiotherapy in Lombardy, Italy: Results of three surveys performed between 2012 and 2016

INTRODUCTION:

Several efforts are being implemented at the European level to measure provision of up-to-date radiation treatments across the continent.

METHODS:

A snapshot survey involving all radiation oncology centers within Lombardy, Italy, was performed in 2012 and repeated in 2014 and 2016, in cooperation with regional governmental officers. Centers were asked to provide detailed information concerning all individual patients being treated on the index day, and to report data on available local resources.

RESULTS:

We observed an increase in the number of centers and of megavoltage units (MVU) (from 76 to 87, i.e., 8.7 MVU per million inhabitants in 2016). Mean number of MVU per center was 2.5. Average age of MVU increased from 5.3 to 7.5 years and patients on the waiting list also increased. Conformal 3D radiotherapy (RT) treatments decreased from 56% to 42% and were progressively replaced by intensity-modulated RT treatments (from 39% to 49%). Waiting times were overall satisfactory. Radiation oncologists treated on average 152 and radiation therapists 100 RT courses per year. Average reimbursement per course was €4,879 (range €2,476-€8,014).

CONCLUSIONS:

The methodology of snapshot survey proved feasible and provided valuable information about radiation oncology provision and accessibility in Lombardy.

Patients' characteristics informing practice: improving individualized nursing care in the radiation oncology setting

PURPOSE

A large number of patients attend for radiotherapy daily. Primary nurses in the study settings aim to individualize care for their patients. The individual characteristics of patients may determine their perceptions of nursing care, and provide guidance in tailoring their care. This study aimed to assess patients' personal characteristics on their perceptions of individualized care (IC) provided by nurses during a course of radiotherapy, and to determine predictor variables that may inform nursing practice.

METHODS

This cross-sectional, exploratory study was conducted in three radiotherapy departments in Australia. Patients (n = 250) completed the Individualized Care Scale_Patient (ICS_P). Data were analyzed using descriptive and inferential statistics, univariate analysis, and multiple regression analysis.

RESULTS

Males reported significantly higher perceptions of IC than females in 7/9 subscales. Patients with head and neck and prostate cancer, as well as those requiring hospitalization during radiotherapy, scored significantly higher in 5/9 subscales. Courses > 30 days, those not receiving chemotherapy, and partnered patients reported greater IC across all subscales. Gender and hospitalization were the main predictor variables for IC.

CONCLUSION

Patients reported moderately high levels of IC during their radiotherapy; however, standard demographic information may provide limited insight into improving care for the individual. Patient characteristics routinely chosen, such as age, gender, and education may not predict how patients perceive their care or support the tailoring of interventions to improve IC. Researching a range of related patient characteristics may prove a more useful concept for future nursing studies aiming to predict outcomes to tailor nursing practice.

National survey on image-guided radiotherapy practice in New Zealand

INTRODUCTION

This survey aimed to assess the use of image-guided radiotherapy (IGRT) within New Zealand (NZ) and evaluate the quality of IGRT delivery.

METHOD

All nine centres in NZ were invited to participate in an online survey in November 2015. Questions were asked on type of IGRT technologies available, IGRT use by tumour site and frequency of imaging. In addition, questions were asked in reference to the American Society for Radiation Oncology (ASTRO) White Paper recommendations on safe practice of IGRT.

RESULTS

Seven of the nine centres (78%) responded. Kilovoltage cone-beam CT (CBCT), kilovoltage planar imaging and megavoltage electronic portal imaging were the most commonly used IGRT technologies. CBCT was most frequently used in gynaecology (100%), genitourinary (86%) and head and neck (86%) sites. Despite the availability of similar IGRT technologies, there was significant variation in their application between centres. All centres used online IGRT; however, the frequency of imaging varied across the tumour sites and individual centres. Daily online IGRT use ranged from 43% to 86% across the tumour sites. Overall, there was good compliance by the NZ centres to the White Paper recommendations, with at least 71% reached for each element. However, the compliance rates for the individual centres ranged between 50% and 100%. The most commonly identified barrier to IGRT use was lack of guidelines/education (43%).

CONCLUSION

Image-guided radiotherapy is widely used in NZ; however, there is a wide variation in its application between centres. Detailed tumour site-specific, imaging modality-specific national guidelines will allow standardization of IGRT practices.

Radiation therapy staffing model 2014

INTRODUCTION

In 2001, the Radiation Therapy Advisory Panel (RTAP) of the Australian Society of Medical Imaging and Radiation Therapy (ASMIRT) (formerly known as Australian Institute of Radiography) published a model for radiation therapist staffing in Australian radiation oncology departments. Between 2012-2013, the model was reviewed to ensure it reflected current radiation therapy practice, technology, and to facilitate forward planning of the radiation therapy workforce.

METHOD

Twenty-four sites from all states participated and provided data on megavoltage simulation, planning and treatment delivery. For simulation and planning activity, the length of time to complete was collected against relevant Medicare Benefits Schedule (MBS) items. For treatment delivery, time to complete activities was collected against a common set of activities. Modelling assumptions are clearly identified in the methodology.

RESULTS

A new model was developed retaining the essential model parameter of full-time equivalent (FTE) radiation therapists (RTs) per linear accelerator operating hour as in the 2001 model but based on contemporary practice and data. The model also includes significant refinements that improve the model's overall utility and flexibility for both workforce planning purposes and for individual services to use the model according to their own organisational needs and service delivery profiles.

CONCLUSION

The ASMIRT believes that the 2014 RT staffing model provides the utility and flexibility for radiation oncology services to best plan RT staffing establishments according to their needs and reflecting the diversity between services and within the sector. It should also provide a robust and valid basis for governments and service planners to use as a guide in workforce planning into the future.

Survey of image-guided radiotherapy use in Australia

INTRODUCTION

This study aimed to evaluate the current use of imaging technologies for planning and delivery of radiotherapy (RT) in Australia.

METHODS

An online survey was emailed to all Australian RT centres in August 2015. The survey inquired about imaging practices during planning and treatment delivery processes. Participants were asked about the types of image-guided RT (IGRT) technologies and the disease sites they were used for, reasons for implementation, frequency of imaging and future plans for IGRT use in their department.

RESULTS

The survey was completed by 71% of Australian RT centres. All respondents had access to computed tomography (CT) simulators and regularly co-registered the following scans to the RT: diagnostic CT (50%), diagnostic magnetic resonance imaging (MRI) (95%), planning MRI (34%), planning positron emission tomography (PET) (26%) and diagnostic PET (97%) to aid in tumour delineation. The main reason for in-room IGRT implementation was the use of highly conformal techniques, while the most common reason for under-utilisation was lack of equipment capability. The most commonly used IGRT modalities were kilovoltage (kV) cone-beam CT (CBCT) (97%), kV electronic portal image (EPI) (89%) and megavoltage (MV) EPI (75%). Overall, participants planned to increase IGRT use in planning (33%) and treatment delivery (36%).

CONCLUSIONS

IGRT is widely used among Australian RT centres. On the basis of future plans of respondents, the installation of new imaging modalities is expected to increase for both planning and treatment.

What are the current and future requirements for magnetic resonance imaging interpretation skills in radiotherapy? A critical review

Purpose

Increasing usage of magnetic resonance imaging (MRI) in radiotherapy (RT) and the advent of MRI-based image-guided radiotherapy (IGRT) suggests a need for additional training within the RT profession. This critical review aimed to identify potential gaps in knowledge by evaluating the current skill base in MRI among therapeutic radiographers as evidenced by published research.

Methods

Papers related to MRI usage were retrieved. Topic areas included outlining, planning and IGRT; diagnosis, follow-up and staging-related papers were excluded. After selection and further text analysis, papers were grouped by tumour site and year of publication.

Results

The literature search and filtering resulted in a total of 123 papers, of which 66 were related to ‘outlining’, 37 to ‘planning’ and 20 to ‘IGRT’. The main sites of existing MRI expertise in RT were brain, central nervous system, prostate, and head and neck tumours. Expertise was clearly related to regions where MRI offered improved soft-tissue contrast. MRI studies within RT have been published from 2007 onwards at a steadily increasing rate.

Conclusion

Current use of MRI in RT is mainly restricted to sites where MRI offers a considerable imaging advantage over computed tomography. Given the changing use of MRI for image guidance, emerging therapeutic radiographers will require training in MRI interpretation across a wider range of anatomical regions.

Practice patterns of radiation therapy technology in Australia: results of a national audit

INTRODUCTION

This article presents the results of a single-day census of radiation therapy (RT) treatment and technology use in Australia. The primary aim of the study was to ascertain patterns of RT practice and technology in use across Australia. These data were primarily collated to inform curriculum development of academic programs, thereby ensuring that training is matched to workforce patterns of practice.

METHODS

The study design was a census method with all 59 RT centres in Australia being invited to provide quantitative summary data relating to patient case mix and technology use on a randomly selected but common date. Anonymous and demographic-free data were analysed using descriptive statistics.

RESULTS

Overall data were provided across all six Australian States by 29 centres of a possible 59, yielding a response rate of 49% and representing a total of 2743 patients. Findings from this study indicate the increasing use of emerging intensity-modulated radiotherapy (IMRT), image fusion and image-guided radiation therapy (IGRT) technology in Australian RT planning and delivery phases. IMRT in particular was used for 37% of patients, indicating a high uptake of the technology in Australia when compared to other published data. The results also highlight the resource-intensive nature of benign tumour radiotherapy.

CONCLUSIONS

In the absence of routine national data collection, the single-day census method offers a relatively convenient means of measuring and tracking RT resource utilisation. Wider use of this tool has the potential to not only track trends in technology implementation but also inform evidence-based guidelines for referral and resource planning.