Title: Making real-time adaptive radiotherapy possible
Funder: Health Education England

Abstract: Advances in technology, such as image-guided radiotherapy (IGRT) and intensity-modulated radiotherapy (IMRT) have enabled us to deliver increasing dose to the tumour whilst minimising dose to normal tissues and, thus, improve patient outcomes. Adaptive radiotherapy (ART) has the potential to further improve patient outcomes by delivering radiotherapy according to, not only the position of the patient and tumour at the time of treatment, but also the shape of the tumour and the relative positions of healthy organs. Tumours in the pelvic region (prostate, bladder, cervix and rectum) can change significantly in both position and shape during a course of radiotherapy because of changes in bladder, rectal and small bowel volumes. Real-time ART would require many professionals to be present, which would be resource-intensive and time-consuming, but this is currently the only option.The hypothesis driving my proposal is that radiographers, with the aid of a decision tool and training, can deliver high quality ART, with minimum use of multi-disciplinary resources, in a time that is acceptable to patients and the radiotherapy department. The work will be undertaken in 5 inter-related work packages (WP). WP1: Using a training needs assessment methodology, I will first establish the knowledge and criteria that clinicians use to make the decision to re-plan by using an Analytical Hierarchical Process. Using the key and core criteria identified I will quantify baseline knowledge of the radiographers and use a mixed methods approach to determine any gaps in knowledge. I will address the knowledge gaps by creating a training programme which will be evaluated with pre- and post-test assessment. The output will be a training programme for the delivery of ART. WP2: I will use statistical classifier approaches to create computer algorithms and flowcharts that will embody the decision-making logic and processes. Using the flowcharts or computer algorithms I will create a novel methodology for a workflow to deliver ART. The output will be a decision tool to enable the delivery of ART WP3: I will determine the feasibility of the training programme and workflow by establishing concordance between radiographer and doctors' decision to re-plan off-line. I will assess the potential impact of ART by comparing the dose received using standard of care treatment and ART .WP4: I will establish the feasibility on-line and determine radiographer and doctor concordance at the time of treatment. I will use a randomised controlled cross over trial to determine the concordance of doctors decisions with radiographers using the tool. The cost effectiveness of the workflow will be established using discrete event simulation. WP5: I will test the generalisability in other centres. The results of this work will establish national/international guidelines for radiographers' training needs to deliver ART.

Lay abstract: Aim: To investigate how doctors decide to adjust radiotherapy to account for changes in position and shape of the patient's body and the cancer and so create a guide for radiographers to make the same decision. The result will be a safe, precise and effective radiotherapy treatment, in a less time consuming manner for the patient. Background: Radiotherapy uses high energy X-Rays to kill cancer cells and is delivered daily by radiographers. The treatment process begins when the patient attends for a radiotherapy planning CT scan. The radiographers help the patient into a position for radiotherapy, and CT images are taken, which are used to create a patient treatment plan. The treatment plan is created on a computer which maps where the radiation needs to be directed so that the cancer receives a radiation dose sufficient to kill the tumour, while normal parts of the body receive much lower doses. The doctor approves the treatment plan. This preparatory phase involves physicists, radiographers and doctors and takes two weeks or more On the day of treatment, the radiographers help the patient into the same position as they were in when the planning CT scan was performed. The radiographers take treatment images to check if the patient's body contour and the position of the cancer have changed since planning. If so, the treatment bed can be moved so the patient is in a better position and the treatment is delivered. This is called image-guided radiotherapy (IGRT). The same treatment plan is used every day, unless something major changes, in which case the patient has to go back to CT and the treatment is re-planned from scratch. Changing practice: A new era is beginning which will improve treatment by allowing precise adjustments to be made each day of treatment. The additional adjustments will account for changes in the shape of the cancer and the patient's body contour. This is called 'adaptive radiotherapy' (ART). Currently any ART adjustments have to be made by the doctor and planning staff, which delays the treatment by 3-4 days. In the meantime, treatment proceeds using the original, unmodified plan. What next?: The benefits of ART would be much greater if changes could be made before the treatment every day. The radiation dose would be sculpted around the shape of the cancer which could cause less damage to the normal parts of the body and allow precise treatment to the cancer. This would require radiographers, physicists, and, critically, doctors to be present at the treatment unit at the same time. This would be a time-consuming process; taking 30-50mins compared to the usual practice of 10-20mins and would mean fewer patients would be treated each day. This has been identified as a major challenge to ART in other countries, and it represents a potential roadblock to its adoption in the UK. This project will pursue the real-time delivery of ART, with radiographers trained to make decisions on adjustments to treatment. I will collaborate with experts in computing, economics and education. I will investigate how the doctors make the decisions, and create a decision guide, with a training package, to help the radiographers to make the decisions. I will test the guide and training package using images taken of previously treated patients. I will test it at the time of treatment to explore if radiographers can make the same decisions as doctors. The patients will also be asked about their experience of each method of treatment. I will then test it in other radiotherapy centres to make sure it can be used throughout the NHS.

Research activity codes: 6.5 RADIOTHERAPY AND OTHER NON-INVASIVE THERAPIES
Health categories: CANCER AND NEOPLASMS