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Benson R, Rodgers J, Nelder C, Clough A, Pitt E, Parker J, Whiteside L, Davies L, Bailey R, McMahon J, Kolbe H, Cree A, Dubec M, Van Herk M, Choudhury A, Hoskin P, Eccles C. The impact of an educational tool in cervix image registration across three imaging modalities. Br J Radiol 2022; 95:20211402. [PMID: 35616660 PMCID: PMC10996960 DOI: 10.1259/bjr.20211402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 04/21/2022] [Accepted: 05/18/2022] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVES Accurate image registration is vital in cervical cancer where changes in both planning target volume (PTV) and organs at risk (OARs) can make decisions regarding image registration complicated. This work aims to determine the impact of a dedicated educational tool compared with experience gained in MR-guided radiotherapy (MRgRT). METHODS 10 therapeutic radiographers acted as observers and were split into two groups based on previous experience with MRgRT and Monaco treatment planning system. Three CBCT-CT, three MR-CT and two MR-MR registrations were completed per patient by each observer. Observers recorded translations, time to complete image registration and confidence. Data were collected in two phases; prior to and following the introduction of a cervix registration guide. RESULTS No statistically significant differences were noted between imaging modalities. Each group was assessed independently pre- and post-education, no statistically significant differences were noted in either CBCT-CT or MR-CT imaging. Group 1 MR-MR imaging showed a statistically significant reduction in interobserver variability (p=0.04), in Group 2, the result was not statistically significant (p=0.06). Statistically significant increases in confidence were seen in all three modalities (p≤0.05). CONCLUSIONS At The Christie NHS Foundation Trust, radiographers consistently registered images across three different imaging modalities regardless of their previous experience. The implementation of an image registration guide had limited impact on inter- and intraobserver variability. Radiographers' confidence showed statistically significant improvements following the use of the registration manual. ADVANCES IN KNOWLEDGE This work helps evaluate training methods for novel roles that are developing in MRgRT.
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Affiliation(s)
- Rebecca Benson
- Department of Radiotherapy, The Christie Hospital NHS
Trust, Manchester,
UK
| | - John Rodgers
- Department of Radiotherapy, The Christie Hospital NHS
Trust, Manchester,
UK
| | - Claire Nelder
- Department of Radiotherapy, The Christie Hospital NHS
Trust, Manchester,
UK
| | - Abigael Clough
- Department of Radiotherapy, The Christie Hospital NHS
Trust, Manchester,
UK
| | - Eleanor Pitt
- Department of Radiotherapy, The Christie Hospital NHS
Trust, Manchester,
UK
| | - Jacqui Parker
- Department of Radiotherapy, The Christie Hospital NHS
Trust, Manchester,
UK
| | - Lee Whiteside
- Department of Radiotherapy, The Christie Hospital NHS
Trust, Manchester,
UK
| | - Lucy Davies
- Department of Radiotherapy, The Christie Hospital NHS
Trust, Manchester,
UK
| | - Rachael Bailey
- Department of Radiotherapy, The Christie Hospital NHS
Trust, Manchester,
UK
| | - John McMahon
- Department of Radiotherapy, The Christie Hospital NHS
Trust, Manchester,
UK
| | - Hope Kolbe
- Department of Radiotherapy, The Christie Hospital NHS
Trust, Manchester,
UK
| | - Anthea Cree
- Department of Clinical Oncology, The Clatterbridge Cancer
Centre, Liverpool,
UK
| | - Michael Dubec
- Department of Medical Physics and Engineering, The Christie NHS
Foundation Trust, Manchester,
UK
| | - Marcel Van Herk
- Department of Clinical Oncology, The Christie NHS Foundation
Trust, Manchester,
UK
- Division of Cancer Sciences, School of Medical Sciences,
Faculty of Biology, Medicine and Health, University of Manchester,
Manchester Academic Health Science Centre,
Manchester, UK
| | - Ananya Choudhury
- Department of Clinical Oncology, The Christie NHS Foundation
Trust, Manchester,
UK
- Division of Cancer Sciences, School of Medical Sciences,
Faculty of Biology, Medicine and Health, University of Manchester,
Manchester Academic Health Science Centre,
Manchester, UK
| | - Peter Hoskin
- Department of Clinical Oncology, The Christie NHS Foundation
Trust, Manchester,
UK
- Division of Cancer Sciences, School of Medical Sciences,
Faculty of Biology, Medicine and Health, University of Manchester,
Manchester Academic Health Science Centre,
Manchester, UK
| | - Cynthia Eccles
- Department of Radiotherapy, The Christie Hospital NHS
Trust, Manchester,
UK
- Division of Cancer Sciences, School of Medical Sciences,
Faculty of Biology, Medicine and Health, University of Manchester,
Manchester Academic Health Science Centre,
Manchester, UK
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Whiteside L, McDaid L, Hales RB, Rodgers J, Dubec M, Huddart RA, Choudhury A, Eccles CL. To see or not to see: Evaluation of magnetic resonance imaging sequences for use in MR Linac-based radiotherapy treatment. J Med Imaging Radiat Sci 2022; 53:362-373. [PMID: 35850925 DOI: 10.1016/j.jmir.2022.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 06/01/2022] [Accepted: 06/20/2022] [Indexed: 11/23/2022]
Abstract
BACKGROUND/PURPOSE This work evaluated the suitability of MR derived sequences for use in online adaptive RT workflows on a 1.5 Tesla (T) MR-Linear Accelerator (MR Linac). MATERIALS/METHODS Non-patient volunteers were recruited to an ethics approved MR Linac imaging study. Participants attended 1-3 imaging sessions in which a combination of DIXON, 2D and 3D volumetric T1 and T2 weighted images were acquired axially, with volunteers positioned using immobilisation devices typical for radiotherapy to the anatomical region being scanned. Images from each session were appraised by three independent reviewers to determine optimal sequences over six anatomical regions: head and neck, female and male pelvis, thorax (lung), thorax (breast/chest wall) and abdomen. Site specific anatomical structures were graded by the perceived ability to accurately contour a typical organ at risk. Each structure was independently graded on a 4-point Likert scale as 'Very Clear', 'Clear', 'Unclear' or 'Not visible' by observers, consisting of radiographers (therapeutic and diagnostic) and clinicians. RESULTS From July 2019 to September 2019, 18 non-patient volunteers underwent 24 imaging sessions in the following anatomical regions: head and neck (n=3), male pelvis (n=4), female pelvis (n=5), lung/oesophagus (n=5) abdomen (n=4) and chest wall/breast (n=3). T2 sequences were the most preferred for perceived ability to contour anatomy in both male and female pelvis. For all other sites T1 weighted DIXON sequences were most favourable. CONCLUSION This study has determined the preferential sequence selection for organ visualisation, as a pre-requisite to our institution adopting MR-guided radiotherapy for a more diverse range of disease sites.
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Affiliation(s)
- Lee Whiteside
- The Christie NHS Foundation Trust, Department of Radiotherapy, Manchester, United Kingdom.
| | - Lisa McDaid
- The Christie NHS Foundation Trust, Department of Radiotherapy, Manchester, United Kingdom
| | - Rosie B Hales
- The Christie NHS Foundation Trust, Department of Radiotherapy, Manchester, United Kingdom
| | - John Rodgers
- The Christie NHS Foundation Trust, Department of Radiotherapy, Manchester, United Kingdom
| | - Michael Dubec
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom; Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, United Kingdom
| | - Robert A Huddart
- The Institute of Cancer Research, London UK; The Royal Marsden, London, United Kingdom
| | - Ananya Choudhury
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom; Department of Clinical Oncology, The Christie NHS Foundation Trust, United Kingdom
| | - Cynthia L Eccles
- The Christie NHS Foundation Trust, Department of Radiotherapy, Manchester, United Kingdom; Division of Cancer Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.
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MRI-guided Radiotherapy (MRgRT) for treatment of Oligometastases: Review of clinical applications and challenges. Int J Radiat Oncol Biol Phys 2022; 114:950-967. [PMID: 35901978 DOI: 10.1016/j.ijrobp.2022.07.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 07/18/2022] [Accepted: 07/19/2022] [Indexed: 11/23/2022]
Abstract
PURPOSE Early clinical results on the application of magnetic resonance imaging (MRI) coupled with a linear accelerator to deliver MR-guided radiation therapy (MRgRT) have demonstrated feasibility for safe delivery of stereotactic body radiotherapy (SBRT) in treatment of oligometastatic disease. Here we set out to review the clinical evidence and challenges associated with MRgRT in this setting. METHODS AND MATERIALS We performed a systematic review of the literature pertaining to clinical experiences and trials on the use of MRgRT primarily for the treatment of oligometastatic cancers. We reviewed the opportunities and challenges associated with the use of MRgRT. RESULTS Benefits of MRgRT pertaining to superior soft-tissue contrast, real-time imaging and gating, and online adaptive radiotherapy facilitate safe and effective dose escalation to oligometastatic tumors while simultaneously sparing surrounding healthy tissues. Challenges concerning further need for clinical evidence and technical considerations related to planning, delivery, quality assurance (QA) of hypofractionated doses, and safety in the MRI environment must be considered. CONCLUSIONS The promising early indications of safety and effectiveness of MRgRT for SBRT-based treatment of oligometastatic disease in multiple treatment locations should lead to further clinical evidence to demonstrate the benefit of this technology.
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Zhang W, Li X, Lin T, Ma F, Ma X, Wu X, Sun Y, Sun X. A model to guide the management and decision of re-planning during radiotherapy for cervical cancer. Transl Cancer Res 2021; 10:5352-5363. [PMID: 35116382 PMCID: PMC8797880 DOI: 10.21037/tcr-21-2545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 12/17/2021] [Indexed: 12/24/2022]
Abstract
BACKGROUND To establish a model to predict whether re-planning is needed in the process of cervical cancer radiotherapy. METHODS We collected the clinical indexes of 132 patients diagnosed with cervical cancer receiving concurrent chemotherapy and radiotherapy, including 33 factors about tumor markers [carcinoembryonic antigen (CEA), cancer antigen 125 (CA-125), squamous cell carcinoma antigen (SCC)], tumor volume, rectal volume, bladder volume, volumes receiving 30-50 Gy in organs-at-risk (OARs), and the maximum dose (Dmax) received by 1-2 cc in OARs. We established a multivariate model for re-planning evaluation via principal component analysis, and then verified the model based on the internal data. RESULTS We identified the dose index (P1), tumor size index (P2), and volumes receiving 30-50 Gy in OARs and the tumor (P3) as the three most weighted factors of the re-planning model. We set the cut-off for the re-planning modification requirement at 1. The model was consistent with R = 0.12P1 + 0.21P2 + 0.31P3, and it performed accurately that area under the test set characteristics curve (AUC) =0.826]. CONCLUSIONS Our proposed method can help to reduce image re-examination during treatment, decrease toxicities in OARs, shorten the radiotherapy course, lessen oncologists' efforts, and save medical resources.
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Affiliation(s)
- Wei Zhang
- Department of Radiation Oncology, Affiliated People’s Hospital of Inner Mongolia Medical University, Hohhot, China
| | - Xiuhua Li
- Department of Gynaecology, Fujian Cancer Hospital, The Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Tingting Lin
- Department of Radiation and Medical Oncology, Affiliated Sanming First Hospital of Fujian Medical University, Sanming, China
| | - Fang Ma
- Department of Radiation Oncology, Affiliated Hospital of Inner Mongolia Medical University, Hohhot, China
| | - Xiaoyu Ma
- Department of Radiation Oncology, Affiliated Hospital of Inner Mongolia Medical University, Hohhot, China
| | - Xiaoli Wu
- Department of Radiation Oncology, Affiliated Hospital of Inner Mongolia Medical University, Hohhot, China
| | - Yingming Sun
- Department of Radiation and Medical Oncology, Affiliated Sanming First Hospital of Fujian Medical University, Sanming, China
| | - Xiaoge Sun
- Department of Radiation Oncology, Affiliated Hospital of Inner Mongolia Medical University, Hohhot, China
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Low dose cone beam CT for paediatric image-guided radiotherapy: Image quality and practical recommendations. Radiother Oncol 2021; 163:68-75. [PMID: 34343544 DOI: 10.1016/j.radonc.2021.07.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 07/22/2021] [Accepted: 07/25/2021] [Indexed: 12/25/2022]
Abstract
PURPOSE Cone beam CT (CBCT) is used in paediatric image-guided radiotherapy (IGRT) for patient setup and internal anatomy assessment. Adult CBCT protocols lead to excessive doses in children, increasing the risk of radiation-induced malignancies. Reducing imaging dose increases quantum noise, degrading image quality. Patient CBCTs also include 'anatomical noise' (e.g. motion artefacts), further degrading quality. We determine noise contributions in paediatric CBCT, recommending practical imaging protocols and thresholds above which increasing dose yields no improvement in image quality. METHODS AND MATERIALS Sixty CBCTs including the thorax or abdomen/pelvis from 7 paediatric patients (aged 6-13 years) were acquired at a range of doses and used to simulate lower dose scans, totalling 192 scans (0.5-12.8 mGy). Noise measured in corresponding regions of each patient and a 10-year-old phantom were compared, modelling total (including anatomical) noise, and quantum noise contributions as a function of dose. Contrast-to-noise ratio (CNR) was measured between fat/muscle. Soft tissue registration was performed on the kidneys, comparing accuracy to the highest dose scans. RESULTS Quantum noise contributed <20% to total noise in all cases, suggesting anatomical noise is the largest determinant of image quality in the abdominal/pelvic region. CNR exceeded 3 in over 90% of cases ≥ 1 mGy, and 57% of cases at 0.5 mGy. Soft tissue registration was accurate for doses > 1 mGy. CONCLUSION Anatomical noise dominates quantum noise in paediatric CBCT. Appropriate soft tissue contrast and registration accuracy can be achieved for doses as low as 1 mGy. Increasing dose above 1 mGy holds no benefit in improving image quality or registration accuracy due to the presence of anatomical noise.
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Brooks RL, McCallum HM, Pearson RA, Pilling K, Wyatt J. Are cone beam CT image matching skills transferrable from planning CT to planning MRI for MR-only prostate radiotherapy? Br J Radiol 2021; 94:20210146. [PMID: 33914617 PMCID: PMC8248228 DOI: 10.1259/bjr.20210146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Objectives: Treatment verification for MR-only planning has focused on fiducial marker matching, however, these are difficult to identify on MR. An alternative is using the MRI for soft-tissue matching with cone beam computed tomography images (MR-CBCT). However, therapeutic radiographers have limited experience of MRI. This study aimed to assess transferability of therapeutic radiographers CT-CBCT prostate image matching skills to MR-CBCT image matching. Methods: 23 therapeutic radiographers with 3 months–5 years’ experience of online daily CT-CBCT soft-tissue matching prostate cancer patients participated. Each observer completed a baseline assessment of 10 CT-CBCT prostate soft-tissue image matches, followed by 10 MR-CBCT prostate soft-tissue image match assessment. A MRI anatomy training intervention was delivered and the 10 MR-CBCT prostate soft-tissue image match assessment was repeated. Limits of agreement were calculated as the disagreement of the observers with mean of all observers. Results: Limits of agreement at CT-CBCT baseline were 2.8 mm, 2.8 mm, 0.7 mm (vertical, longitudinal, lateral). MR-CBCT matches prior to training were 3.3 mm, 3.1 mm, 0.9 mm, and after training 2.6 mm, 2.4 mm, 1.1 mm (vertical, longitudinal, lateral). Results show similar limits of agreement across the assessments, and variation reduced following the training intervention. Conclusion: This suggests therapeutic radiographers’ prostate CBCT image matching skills are transferrable to a MRI planning scan, since MR-CBCT matching has comparable observer variation to CT-CBCT matching. Advances in knowledge: This is the first publication assessing interobserver MR-CBCT prostate soft tissue matching in an MR-only pathway.
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Affiliation(s)
- Rachel L Brooks
- Northern Centre for Cancer Care, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Hazel M McCallum
- Northern Centre for Cancer Care, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.,Centre for Cancer, Newcastle University, Newcastle upon Tyne, UK
| | - Rachel A Pearson
- Northern Centre for Cancer Care, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.,Centre for Cancer, Newcastle University, Newcastle upon Tyne, UK
| | - Karen Pilling
- Northern Centre for Cancer Care, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Jonathan Wyatt
- Northern Centre for Cancer Care, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.,Centre for Cancer, Newcastle University, Newcastle upon Tyne, UK
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