1
|
Botnariuc D, Court S, Lourenço A, Gosling A, Royle G, Hussein M, Rompokos V, Veiga C. Evaluation of monte carlo to support commissioning of the treatment planning system of new pencil beam scanning proton therapy facilities. Phys Med Biol 2024; 69:045027. [PMID: 38052092 DOI: 10.1088/1361-6560/ad1272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 12/05/2023] [Indexed: 12/07/2023]
Abstract
Objective. To demonstrate the potential of Monte Carlo (MC) to support the resource-intensive measurements that comprise the commissioning of the treatment planning system (TPS) of new proton therapy facilities.Approach. Beam models of a pencil beam scanning system (Varian ProBeam) were developed in GATE (v8.2), Eclipse proton convolution superposition algorithm (v16.1, Varian Medical Systems) and RayStation MC (v12.0.100.0, RaySearch Laboratories), using the beam commissioning data. All models were first benchmarked against the same commissioning data and validated on seven spread-out Bragg peak (SOBP) plans. Then, we explored the use of MC to optimise dose calculation parameters, fully understand the performance and limitations of TPS in homogeneous fields and support the development of patient-specific quality assurance (PSQA) processes. We compared the dose calculations of the TPSs against measurements (DDTPSvs.Meas.) or GATE (DDTPSvs.GATE) for an extensive set of plans of varying complexity. This included homogeneous plans with varying field-size, range, width, and range-shifters (RSs) (n= 46) and PSQA plans for different anatomical sites (n= 11).Main results. The three beam models showed good agreement against the commissioning data, and dose differences of 3.5% and 5% were found for SOBP plans without and with RSs, respectively. DDTPSvs.Meas.and DDTPSvs.GATEwere correlated in most scenarios. In homogeneous fields the Pearson's correlation coefficient was 0.92 and 0.68 for Eclipse and RayStation, respectively. The standard deviation of the differences between GATE and measurements (±0.5% for homogeneous and ±0.8% for PSQA plans) was applied as tolerance when comparing TPSs with GATE. 72% and 60% of the plans were within the GATE predicted dose difference for both TPSs, for homogeneous and PSQA cases, respectively.Significance. Developing and validating a MC beam model early on into the commissioning of new proton therapy facilities can support the validation of the TPS and facilitate comprehensive investigation of its capabilities and limitations.
Collapse
Affiliation(s)
- D Botnariuc
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, United Kingdom
- Metrology for Medical Physics Centre, National Physical Laboratory, Hampton Road, Teddington, TW11 0LW, United Kingdom
| | - S Court
- Radiotherapy Physics Services, University College London Hospitals NHS Foundation Trust, 250 Euston Road, London, NW1 2PG, United Kingdom
| | - A Lourenço
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, United Kingdom
- Metrology for Medical Physics Centre, National Physical Laboratory, Hampton Road, Teddington, TW11 0LW, United Kingdom
| | - A Gosling
- Radiotherapy Physics Services, University College London Hospitals NHS Foundation Trust, 250 Euston Road, London, NW1 2PG, United Kingdom
| | - G Royle
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, United Kingdom
| | - M Hussein
- Metrology for Medical Physics Centre, National Physical Laboratory, Hampton Road, Teddington, TW11 0LW, United Kingdom
| | - V Rompokos
- Radiotherapy Physics Services, University College London Hospitals NHS Foundation Trust, 250 Euston Road, London, NW1 2PG, United Kingdom
| | - C Veiga
- Department of Medical Physics and Biomedical Engineering, University College London, Gower Street, London, WC1E 6BT, United Kingdom
| |
Collapse
|
2
|
Lim PS, Rompokos V, Bizzocchi N, Gillies C, Gosling A, Royle G, Chang YC, Gaze MN, Gains JE. Pencil Beam Scanning Proton Therapy Case Selection for Paediatric Abdominal Neuroblastoma: Effects of Tumour Location and Bowel Gas. Clin Oncol (R Coll Radiol) 2021; 33:e132-e142. [PMID: 32962907 DOI: 10.1016/j.clon.2020.08.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/28/2020] [Indexed: 12/12/2022]
Abstract
AIMS Pencil beam scanning (PBS) proton therapy is an increasingly used radiation modality for childhood malignancies due to its ability to minimise dose to surrounding organs. However, the dosimetry is extremely sensitive to anatomical and density changes. The aims of this study were to investigate if there is a dosimetric benefit or detriment with PBS for paediatric abdominal neuroblastoma, assess gastrointestinal air variability and its dosimetric consequences, plus identify if there are factors that could assist case selection for PBS referral. MATERIALS AND METHODS Twenty neuroblastoma cases were double-planned with PBS and intensity-modulated arc therapy (IMAT). Cases were divided into unilateral, midline unilateral and midline bilateral locations in relation to the kidneys. Plans were recalculated after the gastrointestinal volume was simulated as air (Hounsfield Units -700) and water (Hounsfield Units 0), then compared with nominal plans (recalculated - nominal, ΔD). Forty-three weekly cone beam computed tomography scans were analysed to quantify gastrointestinal air variability during treatment. RESULTS PBS reduced the mean dose to normal tissues at all tumour locations, particularly unilateral tumours. However, 15% had better dosimetry with IMAT, all of which were midline tumours. Increased gastrointestinal air caused significant compromises to PBS versus IMAT plans for midline tumours [median/maximum ΔD95% clinical target volume (CTV) -2.4%/-15.7% PBS versus 1.4%/0% IMAT, P = 0.003], whereas minimal impact was observed for unilateral tumours (ΔD95% CTV -0.5%/-1.9% PBS versus 0.5%/-0.5% IMAT, P = 0.008). D95% CTV was significantly decreased in PBS plans if planning target volume (PTV) ≥400 cm3 (median -4.1%, P = 0.001) or PTV extension ≥60% anterior to vertebral body (-2.1%, P = 0.002). A larger variation in gastrointestinal air was observed in patients treated under general anaesthesia (median 38.4%) versus awake (11.5%); P = 0.004. CONCLUSION In this planning study, tumours at the unilateral location consistently showed improved dose reductions to normal tissue with minimal dose degradation from increased gastrointestinal air with PBS plans. Tumour location, PTV volume and anterior extension of PTV are useful characteristics in facilitating patient selection for PBS.
Collapse
Affiliation(s)
- P S Lim
- Department of Oncology, University College London Hospitals NHS Foundation Trust, London, UK; Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - V Rompokos
- Department of Radiotherapy Physics, University College London Hospitals NHS Foundation Trust, London, UK
| | - N Bizzocchi
- Centre for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
| | - C Gillies
- Department of Radiotherapy Physics, University College London Hospitals NHS Foundation Trust, London, UK
| | - A Gosling
- Department of Radiotherapy Physics, University College London Hospitals NHS Foundation Trust, London, UK
| | - G Royle
- Department of Oncology, University College London Hospitals NHS Foundation Trust, London, UK; Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Y-C Chang
- Department of Oncology, University College London Hospitals NHS Foundation Trust, London, UK
| | - M N Gaze
- Department of Oncology, University College London Hospitals NHS Foundation Trust, London, UK
| | - J E Gains
- Department of Oncology, University College London Hospitals NHS Foundation Trust, London, UK.
| |
Collapse
|
3
|
Lowe M, Gosling A, Nicholas O, Underwood T, Miles E, Chang YC, Amos RA, Burnet NG, Clark CH, Patel I, Tsang Y, Sisson N, Gulliford S. Comparing Proton to Photon Radiotherapy Plans: UK Consensus Guidance for Reporting Under Uncertainty for Clinical Trials. Clin Oncol (R Coll Radiol) 2020; 32:459-466. [PMID: 32307206 DOI: 10.1016/j.clon.2020.03.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/11/2020] [Accepted: 03/30/2020] [Indexed: 12/11/2022]
Abstract
In the UK, the recent introduction of high-energy proton beam therapy into national clinical practice provides an opportunity for new clinical trials, particularly those comparing proton and photon treatments. However, comparing these different modalities can present many challenges. Although protons may confer an advantage in terms of reduced normal tissue dose, they can also be more sensitive to uncertainty. Uncertainty analysis is fundamental in ensuring that proton plans are both safe and effective in the event of unavoidable discrepancies, such as variations in patient setup and proton beam range. Methods of evaluating and mitigating the effect of these uncertainties can differ from those approaches established for photon therapy treatments, such as the use of expansion margins to assure safety. These differences should be considered when comparing protons and photons. An overview of the effect of uncertainties on proton plans is presented together with an introduction to some of the concepts and terms that should become familiar to those involved in proton therapy trials. This report aims to provide guidance for those engaged in UK clinical trials comparing protons and photons. This guidance is intended to take a pragmatic approach considering the tools that are available to practising centres and represents a consensus across multidisciplinary groups involved in proton therapy in the UK.
Collapse
Affiliation(s)
- M Lowe
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK; Division of Cancer Sciences, School of Medical Sciences, The University of Manchester, Manchester, UK.
| | - A Gosling
- Department of Radiotherapy Physics, University College London Hospitals NHS Foundation Trust, London, UK
| | - O Nicholas
- South West Wales Cancer Centre, Swansea Bay NHS Trust, Swansea, UK; Swansea University Medical School, Swansea University, Swansea, UK; National Radiotherapy Trials Quality Assurance Group, Velindre Cancer Centre, Cardiff, UK
| | - T Underwood
- Division of Cancer Sciences, School of Medical Sciences, The University of Manchester, Manchester, UK
| | - E Miles
- National Radiotherapy Trials Quality Assurance Group, Mount Vernon Hospital, Northwood, Middlesex, UK
| | - Y-C Chang
- Department of Radiotherapy, University College London Hospitals NHS Foundation Trust, London, UK
| | - R A Amos
- Proton and Advanced Radiotherapy Group, Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - N G Burnet
- Division of Cancer Sciences, School of Medical Sciences, The University of Manchester, Manchester, UK; The Christie NHS Foundation Trust, Manchester, UK
| | - C H Clark
- National Radiotherapy Trials Quality Assurance Group, Mount Vernon Hospital, Northwood, Middlesex, UK
| | - I Patel
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK; Division of Cancer Sciences, School of Medical Sciences, The University of Manchester, Manchester, UK
| | - Y Tsang
- National Radiotherapy Trials Quality Assurance Group, Mount Vernon Hospital, Northwood, Middlesex, UK
| | - N Sisson
- National Radiotherapy Trials Quality Assurance Group, The Clatterbridge Cancer Centre NHS Foundation Trust, Bebington, Wirral, UK
| | - S Gulliford
- Department of Radiotherapy Physics, University College London Hospitals NHS Foundation Trust, London, UK; Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| |
Collapse
|
4
|
Greig K, Gosling A, Collins CJ, Boocock J, McDonald K, Addison DJ, Allen MS, David B, Gibbs M, Higham CFW, Liu F, McNiven IJ, O'Connor S, Tsang CH, Walter R, Matisoo-Smith E. Complex history of dog (Canis familiaris) origins and translocations in the Pacific revealed by ancient mitogenomes. Sci Rep 2018; 8:9130. [PMID: 29904060 PMCID: PMC6002536 DOI: 10.1038/s41598-018-27363-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 05/31/2018] [Indexed: 11/22/2022] Open
Abstract
Archaeological evidence suggests that dogs were introduced to the islands of Oceania via Island Southeast Asia around 3,300 years ago, and reached the eastern islands of Polynesia by the fourteenth century AD. This dispersal is intimately tied to human expansion, but the involvement of dogs in Pacific migrations is not well understood. Our analyses of seven new complete ancient mitogenomes and five partial mtDNA sequences from archaeological dog specimens from Mainland and Island Southeast Asia and the Pacific suggests at least three dog dispersal events into the region, in addition to the introduction of dingoes to Australia. We see an early introduction of dogs to Island Southeast Asia, which does not appear to extend into the islands of Oceania. A shared haplogroup identified between Iron Age Taiwanese dogs, terminal-Lapita and post-Lapita dogs suggests that at least one dog lineage was introduced to Near Oceania by or as the result of interactions with Austronesian language speakers associated with the Lapita Cultural Complex. We did not find any evidence that these dogs were successfully transported beyond New Guinea. Finally, we identify a widespread dog clade found across the Pacific, including the islands of Polynesia, which likely suggests a post-Lapita dog introduction from southern Island Southeast Asia.
Collapse
Affiliation(s)
- K Greig
- Department of Anthropology and Archaeology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand.
| | - A Gosling
- Department of Anatomy, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
| | - C J Collins
- Department of Anatomy, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
| | - J Boocock
- Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, 90024, United States of America
| | - K McDonald
- Department of Anatomy, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
| | - D J Addison
- Archaeology Department, American Samoa Power Authority, PO Box 2545, Pago Pago, AS 96799, American Samoa, USA
| | - M S Allen
- Anthropology, School of Social Sciences, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | - B David
- Monash Indigenous Studies Centre, Monash University, 20 Chancellors Walk, Clayton, VIC, 3800, Australia.,ARC Centre of Excellence for Australian Biodiversity & Heritage, Acton, ACT, 2601, Australia
| | - M Gibbs
- School of Humanities, University of New England, Armidale, NSW, 2351, Australia
| | - C F W Higham
- Department of Anthropology and Archaeology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
| | - F Liu
- Institute of History and Philology, Academia Sinica, 128 Academia Rd, Taipei City 115, Taiwan
| | - I J McNiven
- Monash Indigenous Studies Centre, Monash University, 20 Chancellors Walk, Clayton, VIC, 3800, Australia.,ARC Centre of Excellence for Australian Biodiversity & Heritage, Acton, ACT, 2601, Australia
| | - S O'Connor
- Archaeology & Natural History, School of Culture History & Language, College of Asia & the Pacific, Australian National University, Acton, ACT, 2601, Australia.,ARC Centre of Excellence for Australian Biodiversity & Heritage, Acton, ACT, 2601, Australia
| | - C H Tsang
- Institute of History and Philology, Academia Sinica, 128 Academia Rd, Taipei City 115, Taiwan
| | - R Walter
- Department of Anthropology and Archaeology, University of Otago, PO Box 56, Dunedin, 9054, New Zealand
| | - E Matisoo-Smith
- Department of Anatomy, University of Otago, PO Box 56, Dunedin, 9054, New Zealand.
| |
Collapse
|
5
|
Merriman T, Gosling A, Boocock J, Dalbeth N, Stamp L, Stahl E, Choi H, Matisoo-Smith L. OP0158 Mitochondrial Genetic Variation and Susceptibility To Gout in Polynesians. Ann Rheum Dis 2016. [DOI: 10.1136/annrheumdis-2016-eular.4476] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
6
|
Zbar AP, Aslam M, Gold DM, Gatzen C, Gosling A, Kmiot WA. Parameters of the rectoanal inhibitory reflex in patients with idiopathic fecal incontinence and chronic constipation. Dis Colon Rectum 1998; 41:200-8. [PMID: 9556245 DOI: 10.1007/bf02238249] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE The rectoanal inhibitory reflex is a response of the internal anal sphincter to rectal distention, reflecting the functional nature of the anal sampling mechanism of rectal discrimination. The aim of this study was to assess the parameters of the rectoanal inhibitory reflex in healthy volunteers and incontinent and symptomatically constipated patients. METHODS The rectoanal inhibitory reflex was recorded in 42 patients using reproducible threshold volumes. Excitatory and inhibitory latencies, maximum excitatory and inhibitory pressures, amplitude, and slope of inhibition, slope and time of pressure recovery, and area under the inhibitory curve were estimated. Pudendal nerve terminal motor latency and endoanal magnetic resonance imaging were performed in all incontinent patients. RESULTS Significant linear trends were found for most parameters at each sphincter level when analyzed. Recovery time and area under the inhibitory curve differed between the sphincter levels and patient groups, with the most rapid recovery occurring in the distal sphincter of incontinent patients (P < 0.001). These pressure findings were not accounted for by differences in excitation between patient groups. CONCLUSION A coordinated response by the internal anal sphincter to rectal distention with recovery of anal pressure from the distal to the proximal sphincter is suggested. Continence may rely on the character of internal anal sphincter inhibition, and recovery and preoperative assessment of rectoanal inhibitory reflex parameters may be important for predicting functional result following low anastomosis.
Collapse
Affiliation(s)
- A P Zbar
- Academic Department of Colorectal Surgery, Hammersmith Hospital, London, United Kingdom
| | | | | | | | | | | |
Collapse
|
7
|
Handen BL, Breaux AM, Janosky J, McAuliffe S, Feldman H, Gosling A. Effects and noneffects of methylphenidate in children with mental retardation and ADHD. J Am Acad Child Adolesc Psychiatry 1992; 31:455-61. [PMID: 1592777 DOI: 10.1097/00004583-199205000-00011] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Stimulant medication efficacy was evaluated in 14 children with attention-deficit hyperactivity disorder and IQs of 48 to 74 in a double-blind crossover study of two methylphenidate doses and placebo. Dependent measures included behavioral ratings, work output, measures of learning, attention and impulsivity, and direct observation of peer social interactions. Nine children (64%) were methylphenidate-responders, based upon the Conners Hyperactivity Index. Significant gains in on-task behavior and attentional skills were noted with methylphenidate in comparison to placebo. No improvement on measures of learning or social interactions were observed. Results extend and replicate previous research conducted by the authors.
Collapse
Affiliation(s)
- B L Handen
- University of Pittsburgh School of Medicine, Department of Pediatrics, PA
| | | | | | | | | | | |
Collapse
|
8
|
Abstract
The adverse side effects of methylphenidate were evaluated in 27 children with attention deficit hyperactivity disorder and IQs of 48 to 74 who participated in a double-blind study of two doses of methylphenidate and placebo. A checklist of 13 side effects, generated from the Physician's Desk Reference, was completed by teachers. Rates of irritability, anxiety, moodiness, and activity level decreased significantly when comparing the placebo with drug conditions. However, medication for six (22%) of the children was discontinued because of the appearance of motor tics (three children) and severe social withdrawal (two children), suggesting that mentally retarded children with attention deficit hyperactivity disorder may be at a greater risk for developing these side effects than the nonretarded population.
Collapse
Affiliation(s)
- B L Handen
- University of Pittsburgh School of Medicine, Department of Pediatrics, PA
| | | | | | | | | |
Collapse
|
9
|
Handen BL, Breaux AM, Gosling A, Ploof DL, Feldman H. Efficacy of methylphenidate among mentally retarded children with attention deficit hyperactivity disorder. Pediatrics 1990; 86:922-30. [PMID: 2135682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Twelve children with IQ scores of 50 to 74 (educable mental retardation) who met rigorous diagnostic criteria for attention deficit hyperactivity disorder participated in a double-blind crossover study of the efficacy of two doses of methylphenidate compared with placebo. Dependent measures included behavioral ratings, classroom work output, laboratory measures of attention and learning, and direct observations of social behavior. Improvement with medication on the Conners Hyperactivity Index was observed in 75% of subjects. Significant increases in work output, on-task behavior, and attentional skills were associated with methylphenidate. However, gains in measures of attention were not associated with improvement in learning, as measured by a paired associate learning task. Additionally, no significant increases in appropriate social interactions during free play were associated with methylphenidate. The results suggest that mentally retarded children with attention deficit hyperactivity disorder respond to methylphenidate at similar rates and in similar domains to that of the nonretarded population.
Collapse
Affiliation(s)
- B L Handen
- University of Pittsburgh School of Medicine, Pennsylvania
| | | | | | | | | |
Collapse
|