Radiotherapy Quality Assurance: Facilitation of Radiotherapy Research and Implementation of Technology

Hitting the Target: Developing High-quality Evidence for Proton Beam Therapy Through Randomised Controlled Trials

The National Health Service strategy for the delivery of proton beam therapy (PBT) in the UK provides a unique opportunity to deliver high-quality evidence for PBT through randomised controlled trials (RCTs). We present a summary of three UK PBT RCTs in progress, including consideration of their key design characteristics and outcome assessments, to inform and support future PBT trial development. The first three UK multicentre phase III PBT RCTs (TORPEdO, PARABLE and APPROACH), will compare PBT with photon radiotherapy for oropharyngeal squamous cell carcinoma, breast cancer and oligodendroglioma, respectively. All three studies were designed by multidisciplinary teams, which combined expertise from clinicians, clinical trialists and scientists with strong patient advocacy and guidance from national radiotherapy research networks and international collaborators. Consistent across all three studies is a focus on the reduction of long-term radiotherapy-related toxicities and an evaluation of patient-reported outcomes and health-related quality of life, which will address key uncertainties regarding the clinical benefits of PBT. Innovative translational components will provide insights into mechanisms of toxicity and help to frame the key future research questions regarding PBT. The UK radiotherapy research community is developing and delivering an internationally impactful PBT research portfolio. The combination of data from RCTs with prospectively collected data from a national PBT outcomes registry will provide an innovative, high-quality repository for PBT research and the platform to design and deliver future trials of PBT.

One versus three weeks hypofractionated whole breast radiotherapy for early breast cancer treatment: the FAST-Forward phase III RCT

Background

FAST-Forward aimed to identify a 5-fraction schedule of adjuvant radiotherapy delivered in 1 week that was non-inferior in terms of local cancer control and as safe as the standard 15-fraction regimen after primary surgery for early breast cancer. Published acute toxicity and 5-year results are presented here with other aspects of the trial.

Design

Multicentre phase III non-inferiority trial. Patients with invasive carcinoma of the breast (pT1-3pN0-1M0) after breast conservation surgery or mastectomy randomised (1 : 1 : 1) to 40 Gy in 15 fractions (3 weeks), 27 Gy or 26 Gy in 5 fractions (1 week) whole breast/chest wall (Main Trial). Primary endpoint was ipsilateral breast tumour relapse; assuming 2% 5-year incidence for 40 Gy, non-inferiority pre-defined as < 1.6% excess for 5-fraction schedules (critical hazard ratio = 1.81). Normal tissue effects were assessed independently by clinicians, patients and photographs.

Sub-studies

Two acute skin toxicity sub-studies were undertaken to confirm safety of the test schedules. Primary endpoint was proportion of patients with grade ≥ 3 acute breast skin toxicity at any time from the start of radiotherapy to 4 weeks after completion. Nodal Sub-Study patients had breast/chest wall plus axillary radiotherapy testing the same three schedules, reduced to the 40 and 26 Gy groups on amendment, with the primary endpoint of 5-year patient-reported arm/hand swelling.

Limitations

A sequential hypofractionated or simultaneous integrated boost has not been studied.

Participants

Ninety-seven UK centres recruited 4096 patients (1361:40 Gy, 1367:27 Gy, 1368:26 Gy) into the Main Trial from November 2011 to June 2014. The Nodal Sub-Study recruited an additional 469 patients from 50 UK centres. One hundred and ninety and 162 Main Trial patients were included in the acute toxicity sub-studies.

Results

Acute toxicity sub-studies evaluable patients: (1) acute grade 3 Radiation Therapy Oncology Group toxicity reported in 40 Gy/15 fractions 6/44 (13.6%); 27 Gy/5 fractions 5/51 (9.8%); 26 Gy/5 fractions 3/52 (5.8%). (2) Grade 3 common toxicity criteria for adverse effects toxicity reported for one patient. At 71-month median follow-up in the Main Trial, 79 ipsilateral breast tumour relapse events (40 Gy: 31, 27 Gy: 27, 26 Gy: 21); hazard ratios (95% confidence interval) versus 40 Gy were 27 Gy: 0.86 (0.51 to 1.44), 26 Gy: 0.67 (0.38 to 1.16). With 2.1% (1.4 to 3.1) 5-year incidence ipsilateral breast tumour relapse after 40 Gy, estimated absolute differences versus 40 Gy (non-inferiority test) were -0.3% (-1.0-0.9) for 27 Gy (p = 0.0022) and -0.7% (-1.3-0.3) for 26 Gy (p = 0.00019). Five-year prevalence of any clinician-assessed moderate/marked breast normal tissue effects was 40 Gy: 98/986 (9.9%), 27 Gy: 155/1005 (15.4%), 26 Gy: 121/1020 (11.9%). Across all clinician assessments from 1 to 5 years, odds ratios versus 40 Gy were 1.55 (1.32 to 1.83; p < 0.0001) for 27 Gy and 1.12 (0.94-1.34; p = 0.20) for 26 Gy. Patient and photographic assessments showed higher normal tissue effects risk for 27 Gy versus 40 Gy but not for 26 Gy. Nodal Sub-Study reported no arm/hand swelling in 80% and 77% in 40 Gy and 26 Gy at baseline, and 73% and 76% at 24 months. The prevalence of moderate/marked arm/hand swelling at 24 months was 10% versus 7% for 40 Gy compared with 26 Gy.

Interpretation

Five-year local tumour incidence and normal tissue effects prevalence show 26 Gy in 5 fractions in 1 week is a safe and effective alternative to 40 Gy in 15 fractions for patients prescribed adjuvant local radiotherapy after primary surgery for early-stage breast cancer.

Future work

Ten-year Main Trial follow-up is essential. Inclusion in hypofractionation meta-analysis ongoing. A future hypofractionated boost trial is strongly supported.

Trial registration

FAST-Forward was sponsored by The Institute of Cancer Research and was registered as ISRCTN19906132.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 09/01/47) and is published in full in Health Technology Assessment; Vol. 27, No. 25. See the NIHR Funding and Awards website for further award information.

Radiographer-led online image guided adaptive radiotherapy: A qualitative investigation of the therapeutic radiographer role

INTRODUCTION

Online MRI guided adaptive radiotherapy (MRIgRT) is resource intensive. To maintain and increase uptake traditional roles and responsibilities may need refining. This novel study aims to provide an in-depth understanding and subsequent impact of the roles required to deliver on-line adaptive MRIgRT by exploring the current skills and knowledge of radiographers.

METHOD

A purposive sampling approach was used to invite radiographers, clinicians and physicists from centres with experience of MRIgRT to participate. Focus Group Interviews were conducted with two facilitators using a semi-structure interview guide (Appendix 1). Four researchers independently familiarised themselves and coded the data using framework analysis. A consensus thematic framework of ptive Radiotherapy codes and categories was agreed and systematically applied.

RESULTS

Thirty participants took part (Radiographers: N = 18, Physicists: N = 9 and Clinicians: N = 3). Three key themes were identified: 'Current MRIgRT', 'Training' and 'Future Practice'. Current MRIgRT identified a variation in radiographers' roles and responsibilities with pathways ranging from radiographer-led, clinician-light-led and MDT-led. The consensus was to move towards radiographer-led with the need to have a robust on-call service heavily emphasised. Training highlighted the breadth of knowledge required by radiographers including MRI, contouring, planning and dosimetry, and treatment experience. Debate was presented over timing and length of training required. Future Practice identified the need to have radiographers solely deliver MRIgRT, to reduce staff present which was seen as a main driver, and time and resources to train radiographers seen as the main barriers.

CONCLUSION

Radiographer-led MRIgRT is an exciting development because of the potential radiographer role development. A national training framework created collaboratively with all stakeholders and professions involved would ensure consistency in skills and knowledge.

IMPLICATIONS FOR PRACTICE

Role development and changes in education for therapeutic radiographers.

Provision of Organ at Risk Contouring Guidance in UK Radiotherapy Clinical Trials

AIMS

Accurate delineation of organs at risk (OAR) is vital to the radiotherapy planning process. Inaccuracies in OAR delineation arising from imprecise anatomical definitions may affect plan optimisation and risk inappropriate dose delivery to normal tissues. The aim of this study was to review the provision of OAR contouring guidance in National Institute of Health Research Clinical Research Network (NIHR CRN) portfolio clinical trials.

MATERIALS AND METHODS

The National Radiotherapy Quality Trials Assurance (RTTQA) Group carried out a two-round Delphi assessment to determine which OAR descriptions provided optimal guidance.

RESULTS

Eighty-four clinical trials involving radiotherapy quality assurance were identified as either in recruitment or in setup within the NIHR CRN portfolio. Fifty-nine trials mandated OAR contouring. In total there were 412 OAR; 171 were uniquely named; 159 OAR had more than one name associated with a single structure, with the greatest nomenclature variation seen for the femoral head ± neck, the parotid gland, and bowel. The two-round Delphi assessment determined 42 OAR descriptions as providing optimal contouring guidance.

CONCLUSIONS

This study identified the need for OAR nomenclature and contouring guidance consistency across clinical trials. In response to this study and in conjunction with the Global Quality Assurance of Radiation Therapy Clinical Trials Harmonisation Group, the RTTQA Group is in collaboration with international partners to provide consensus recommendations for OAR delineation in clinical trials.

Proton Beam Therapy - the Challenges of Delivering High-quality Evidence of Clinical Benefit

The use of proton beam therapy (PBT) offers the opportunity to improve greater conformality of radiotherapy treatment delivery in some patients. However, it is associated with a high capital cost and the need to build new dedicated facilities. We discuss how the global radiotherapy community can respond to the challenge of producing high-quality evidence of clinical benefit from PBT in adult patients. In the UK, the National Cancer Research Institute-funded Clinical and Radiotherapy Translational group has established the PBT Clinical Trial Strategy Group. An eight-point framework is described that can assist the development and delivery of high-quality clinical trials.

A new era for clinical trial quality assurance: A credentialing programme for RTT led adaptive radiotherapy

•A multi-centre QA programme incorporating adaptive plan selection has been developed.•This novel QA approach has been validated by 71 RTTs from ten UK centres.•A multidisciplinary approach is essential in the development of a credentialing programme.

Novel methodologies for dosimetry audits: Adapting to advanced radiotherapy techniques

With new radiotherapy techniques, treatment delivery is becoming more complex and accordingly, these treatment techniques require dosimetry audits to test advanced aspects of the delivery to ensure best practice and safe patient treatment. This review of novel methodologies for dosimetry audits for advanced radiotherapy techniques includes recent developments and future techniques to be applied in dosimetry audits. Phantom-based methods (i.e. phantom-detector combinations) including independent audit equipment and local measurement equipment as well as phantom-less methods (i.e. portal dosimetry, transmission detectors and log files) are presented and discussed. Methodologies for both conventional linear accelerator (linacs) and new types of delivery units, i.e. Tomotherapy, stereotactic devices and MR-linacs, are reviewed. Novel dosimetry audit techniques such as portal dosimetry or log file evaluation have the potential to allow parallel auditing (i.e. performing an audit at multiple institutions at the same time), automation of data analysis and evaluation of multiple steps of the radiotherapy treatment chain. These methods could also significantly reduce the time needed for audit and increase the information gained. However, to maximise the potential, further development and harmonisation of dosimetry audit techniques are required before these novel methodologies can be applied.

Quality assurance of the SCOPE 1 trial in oesophageal radiotherapy

BACKGROUND

SCOPE 1 was the first UK based multi-centre trial involving radiotherapy of the oesophagus. A comprehensive radiotherapy trials quality assurance programme was launched with two main aims: 1. To assist centres, where needed, to adapt their radiotherapy techniques in order to achieve protocol compliance and thereby enable their participation in the trial. 2. To support the trial's clinical outcomes by ensuring the consistent planning and delivery of radiotherapy across all participating centres.

METHODS

A detailed information package was provided and centres were required to complete a benchmark case in which the delineated target volumes and organs at risk, dose distribution and completion of a plan assessment form were assessed prior to recruiting patients into the trial. Upon recruiting, the quality assurance (QA) programme continued to monitor the outlining and planning of radiotherapy treatments. Completion of a questionnaire was requested in order to gather information about each centre's equipment and techniques relating to their trial participation and to assess the impact of the trial nationally on standard practice for radiotherapy of the oesophagus. During the trial, advice was available for individual planning issues, and was circulated amongst the SCOPE 1 community in response to common areas of concern using bulletins.

RESULTS

36 centres were supported through QA processes to enable their participation in SCOPE1. We discuss the issues which have arisen throughout this process and present details of the benchmark case solutions, centre questionnaires and on-trial protocol compliance. The range of submitted benchmark case GTV volumes was 29.8-67.8cm3; and PTV volumes 221.9-513.3 cm3. For the dose distributions associated with these volumes, the percentage volume of the lungs receiving 20Gy (V20Gy) ranged from 20.4 to 33.5%. Similarly, heart V40Gy ranged from 16.1 to 33.0%. Incidence of incorrect outlining of OAR volumes increased from 50% of centres at benchmark case, to 64% on trial. Sixty-five percent of centres, who returned the trial questionnaire, stated that their standard practice had changed as a result of their participation in the SCOPE1 trial.

CONCLUSIONS

The SCOPE 1 QA programme outcomes lend support to the trial's clinical conclusions. The range of patient planning outcomes for the benchmark case indicated, at the outset of the trial, the significant degree of variation present in UK oesophageal radiotherapy planning outcomes, despite the presence of a protocol. This supports the case for increasingly detailed definition of practice by means of consensus protocols, training and peer review. The incidence of minor inconsistencies of technique highlights the potential for improved QA systems and the need for sufficient resource for this to be addressed within future trials. As indicated in questionnaire responses, the QA exercise as a whole has contributed to greater consistency of oesophageal radiotherapy in the UK via the adoption into standard practice of elements of the protocol.

TRIAL REGISTRATION

The SCOPE1 trial is an International Standard Randomized Controlled Trial, ISRCTN47718479 .

What is the degree of innovation routinely implemented in Dutch radiotherapy centres? A multicentre cross-sectional study

Objective:

To study the implementation of innovation activities in Dutch radiotherapy (RT) centres in a broad sense (product, technological, market and organizational innovations).

Methods:

A descriptive cross-sectional study was conducted in 15 Dutch RT centres. A list of innovations implemented from 2011 to 2013 was drawn up for each centre using semi-structured interviews. These innovations were classified into innovation categories according to previously defined innovation indicators. Where applicable, each innovation was rated by each centre on the effort required to implement it and on its expected effects, to get an impression of how far reaching and radical the innovations were and to be able to compare the number of innovations between centres.

Results:

The participating RT centres in the Netherlands implemented 12 innovations per year on average (range 5–25); this number was not significantly different for academic (n = 13) or non-academic centres (n = 10). Several centres were dealing with the same innovations at the same time. The average required effort and expected output did not differ significantly between product, technological and organizational innovation or between academic and non-academic centres.

Conclusion:

The number of innovations observed per centre varied across a large range, with a large overlap in terms of the type of innovations that were implemented. Registering innovations using the innovation indicators applied in our study would make it possible to improve collaboration between centres, e.g. with common training modules, to avoid duplication of work.

Advances in knowledge:

This study is the first of its kind investigating innovation implementation in RT in a broad sense.

Radiotherapy for Prostate Cancer: is it 'what you do' or 'the way that you do it'? A UK Perspective on Technique and Quality Assurance

AIMS

The treatment of prostate cancer has evolved markedly over the last 40 years, including radiotherapy, notably with escalated dose and targeting. However, the optimal treatment for localised disease has not been established in comparative randomised trials. The aim of this article is to describe the history of prostate radiotherapy trials, including their quality assurance processes, and to compare these with the ProtecT trial.

MATERIALS AND METHODS

The UK ProtecT randomised trial compares external beam conformal radiotherapy, surgery and active monitoring for clinically localised prostate cancer and will report on the primary outcome (disease-specific mortality) in 2016 following recruitment between 1999 and 2009. The embedded quality assurance programme consists of on-site machine dosimetry at the nine trial centres, a retrospective review of outlining and adherence to dose constraints based on the trial protocol in 54 participants (randomly selected, around 10% of the total randomised to radiotherapy, n = 545). These quality assurance processes and results were compared with prostate radiotherapy trials of a comparable era.

RESULTS

There has been an increasingly sophisticated quality assurance programme in UK prostate radiotherapy trials over the last 15 years, reflecting dose escalation and treatment complexity. In ProtecT, machine dosimetry results were comparable between trial centres and with the UK RT01 trial. The outlining review showed that most deviations were clinically acceptable, although three (1.4%) may have been of clinical significance and were related to outlining of the prostate. Seminal vesicle outlining varied, possibly due to several prostate trials running concurrently with different protocols. Adherence to dose constraints in ProtecT was considered acceptable, with 80% of randomised participants having two or less deviations and planning target volume coverage was excellent.

CONCLUSION

The ProtecT trial quality assurance results were satisfactory and comparable with trials of its era. Future trials should aim to standardise treatment protocols and quality assurance programmes where possible to reduce complexities for centres involved in multiple trials.

Clinical impact of IMPORT HIGH trial (CRUK/06/003) on breast radiotherapy practices in the United Kingdom

OBJECTIVE

IMPORT HIGH is a multicentre randomized UK trial testing dose-escalated intensity-modulated radiotherapy (IMRT) after tumour excision in females with early breast cancer and higher than average local recurrence risk. A survey was carried out to investigate the impact of this trial on the adoption of advanced breast radiotherapy (RT) techniques in the UK.

METHODS

A questionnaire was sent to all 26 IMPORT HIGH recruiting RT centres to determine whether the trial has influenced non-trial breast RT techniques in terms of volume delineation, dosimetry, treatment delivery and verification. In order to compare the clinical practice of breast RT between IMPORT HIGH and non-IMPORT HIGH centres, parts of the Royal College of Radiologists (RCR) breast RT audit result were used in this study.

RESULTS

26/26 participating centres completed the questionnaire. After joining the trial, the number of centres routinely using tumour bed clips to guide whole-breast RT rose from 5 (19%) to 21 (81%). 20/26 (77%) centres now contour target volumes and organs at risk (OARs) in some or all patients compared with 14 (54%) before the trial. 14/26 (54%) centres offer inverse-planned IMRT for selected non-trial patients with breast cancer, and 10/14 (71%) have adopted the IMPORT HIGH trial protocol for target volume and OARs dose constraints. Only 2/26 (8%) centres used clip information routinely for breast treatment verification prior to IMPORT HIGH, a minority that has since risen to 7/26 (27%). Data on 1386 patients was included from the RCR audit. This suggested that more cases from IMPORT HIGH centres had surgical clips implanted (83 vs 67%), were treated using CT guided planning with full three-dimensional dose compensation (100 vs 75%), and were treated with photon boost RT (30 vs 8%).

CONCLUSION

The study suggests that participation in the IMPORT HIGH trial has played an important part in providing the guidance and support networks needed for the safe integration of advanced RT techniques, where appropriate, as a standard of care for breast cancer patients treated at participating cancer centres.

ADVANCES IN KNOWLEDGE

We investigated the impact of the IMPORT HIGH trial on the adoption of advanced breast RT techniques in the UK and the trial has influenced non-trial breast RT techniques in terms of volume delineation, dosimetry, treatment delivery and verification.

Inter-departmental dosimetry audits - development of methods and lessons learned

External dosimetry audits give confidence in the safe and accurate delivery of radiotherapy. In the United Kingdom, such audits have been performed for almost 30 years. From the start, they included clinically relevant conditions, as well as reference machine output. Recently, national audits have tested new or complex techniques, but these methods are then used in regional audits by a peer-to-peer approach. This local approach builds up the radiotherapy community, facilitates communication, and brings synergy to medical physics.