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Wong SL, Alshaikhi J, Grimes H, Amos RA, Poynter A, Rompokos V, Gulliford S, Royle G, Liao Z, Sharma RA, Mendes R. Retrospective Planning Study of Patients with Superior Sulcus Tumours Comparing Pencil Beam Scanning Protons to Volumetric-Modulated Arc Therapy. Clin Oncol (R Coll Radiol) 2021; 33:e118-e131. [PMID: 32798157 PMCID: PMC7883303 DOI: 10.1016/j.clon.2020.07.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/30/2020] [Accepted: 07/22/2020] [Indexed: 12/25/2022]
Abstract
AIMS Twenty per cent of patients with non-small cell lung cancer present with stage III locally advanced disease. Precision radiotherapy with pencil beam scanning (PBS) protons may improve outcomes. However, stage III is a heterogeneous group and accounting for complex tumour motion is challenging. As yet, it remains unclear as to whom will benefit. In our retrospective planning study, we explored if patients with superior sulcus tumours (SSTs) are a select cohort who might benefit from this treatment. MATERIALS AND METHODS Patients with SSTs treated with radical radiotherapy using four-dimensional planning computed tomography between 2010 and 2015 were identified. Tumour motion was assessed and excluded if greater than 5 mm. Photon volumetric-modulated arc therapy (VMAT) and PBS proton single-field optimisation plans, with and without inhomogeneity corrections, were generated retrospectively. Robustness analysis was assessed for VMAT and PBS plans involving: (i) 5 mm geometric uncertainty, with an additional 3.5% range uncertainty for proton plans; (ii) verification plans at maximal inhalation and exhalation. Comparative dosimetric and robustness analyses were carried out. RESULTS Ten patients were suitable. The mean clinical target volume D95 was 98.1% ± 0.4 (97.5-98.8) and 98.4% ± 0.2 (98.1-98.9) for PBS and VMAT plans, respectively. All normal tissue tolerances were achieved. The same four PBS and VMAT plans failed robustness assessment. Inhomogeneity corrections minimally impacted proton plan robustness and made it worse in one case. The most important factor affecting target coverage and robustness was the clinical target volume entering the spinal canal. Proton plans significantly reduced the mean lung dose (by 21.9%), lung V5, V10, V20 (by 47.9%, 36.4%, 12.1%, respectively), mean heart dose (by 21.4%) and thoracic vertebra dose (by 29.2%) (P < 0.05). CONCLUSIONS In this planning study, robust PBS plans were achievable in carefully selected patients. Considerable dose reductions to the lung, heart and thoracic vertebra were possible without compromising target coverage. Sparing these lymphopenia-related organs may be particularly important in this era of immunotherapy.
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Affiliation(s)
- S-L Wong
- University College London Cancer Institute, London, UK; Department of Clinical Oncology, University College London Hospitals NHS Foundation Trust, London, UK.
| | - J Alshaikhi
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK; Department of Radiotherapy Physics, University College London Hospitals NHS Foundation Trust, London, UK; Saudi Particle Therapy Centre, Riyadh, Saudi Arabia
| | - H Grimes
- Department of Radiotherapy Physics, University College London Hospitals NHS Foundation Trust, London, UK
| | - R A Amos
- Department of Clinical Oncology, University College London Hospitals NHS Foundation Trust, London, UK; Department of Radiotherapy Physics, University College London Hospitals NHS Foundation Trust, London, UK; Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - A Poynter
- Department of Radiotherapy Physics, University College London Hospitals NHS Foundation Trust, London, UK
| | - V Rompokos
- Department of Radiotherapy Physics, University College London Hospitals NHS Foundation Trust, London, UK
| | - S Gulliford
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK; Department of Radiotherapy Physics, University College London Hospitals NHS Foundation Trust, London, UK
| | - G Royle
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Z Liao
- Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - R A Sharma
- University College London Cancer Institute, London, UK; Department of Clinical Oncology, University College London Hospitals NHS Foundation Trust, London, UK; NIHR University College London Hospitals Biomedical Research Centre, London, UK
| | - R Mendes
- Department of Clinical Oncology, University College London Hospitals NHS Foundation Trust, London, UK
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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.
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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
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Gutierrez A, Rompokos V, Li K, Gillies C, D’Souza D, Solda F, Fersht N, Chang YC, Royle G, Amos RA, Underwood T. The impact of proton LET/RBE modeling and robustness analysis on base-of-skull and pediatric craniopharyngioma proton plans relative to VMAT. Acta Oncol 2019; 58:1765-1774. [PMID: 31429359 PMCID: PMC6882303 DOI: 10.1080/0284186x.2019.1653496] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 08/04/2019] [Indexed: 11/04/2022]
Abstract
Purpose: Pediatric craniopharyngioma, adult base-of-skull sarcoma and chordoma cases are all regarded as priority candidates for proton therapy. In this study, a dosimetric comparison between volumetric modulated arc therapy (VMAT) and intensity modulated proton therapy (IMPT) was first performed. We then investigated the impact of physical and biological uncertainties. We assessed whether IMPT plans remained dosimetrically superior when such uncertainty estimates were considered, especially with regards to sparing organs at risk (OARs).Methodology: We studied 10 cases: four chondrosarcoma, two chordoma and four pediatric craniopharyngioma. VMAT and IMPT plans were created according to modality-specific protocols. For IMPT, we considered (i) variable RBE modeling using the McNamara model for different values of (α/β)x, and (ii) robustness analysis with ±3 mm set-up and 3.5% range uncertainties.Results: When comparing the VMAT and IMPT plans, the dosimetric advantages of IMPT were clear: IMPT led to reduced integral dose and, typically, improved CTV coverage given our OAR constraints. When physical robustness analysis was performed for IMPT, some uncertainty scenarios worsened the CTV coverage but not usually beyond that achieved by VMAT. Certain scenarios caused OAR constraints to be exceeded, particularly for the brainstem and optical chiasm. However, variable RBE modeling predicted even more substantial hotspots, especially for low values of (α/β)x. Variable RBE modeling often prompted dose constraints to be exceeded for critical structures.Conclusion: For base-of-skull and pediatric craniopharyngioma cases, both physical and biological robustness analyses should be considered for IMPT: these analyses can substantially affect the sparing of OARs and comparisons against VMAT. All proton RBE modeling is subject to high levels of uncertainty, but the clinical community should remain cognizant possible RBE effects. Careful clinical and imaging follow-up, plus further research on end-of-range RBE mitigation strategies such as LET optimization, should be prioritized for these cohorts of proton patients.
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Affiliation(s)
- A. Gutierrez
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - V. Rompokos
- Department of Radiotherapy Physics, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - K. Li
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - C. Gillies
- Department of Radiotherapy Physics, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - D. D’Souza
- Department of Radiotherapy Physics, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - F. Solda
- Department of Clinical Oncology, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - N. Fersht
- Department of Clinical Oncology, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Y.-C. Chang
- Department of Clinical Oncology, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - G. Royle
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - R. A. Amos
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - T. Underwood
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
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Ranger A, Dunlop A, Hutchinson K, Convery H, Maclennan MK, Chantler H, Twyman N, Rose C, McQuaid D, Amos RA, Griffin C, deSouza NM, Donovan E, Harris E, Coles CE, Kirby A. A Dosimetric Comparison of Breast Radiotherapy Techniques to Treat Locoregional Lymph Nodes Including the Internal Mammary Chain. Clin Oncol (R Coll Radiol) 2018; 30:346-353. [PMID: 29483041 DOI: 10.1016/j.clon.2018.01.017] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [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: 11/16/2017] [Revised: 01/02/2018] [Accepted: 01/03/2018] [Indexed: 10/17/2022]
Abstract
AIMS Radiotherapy target volumes in early breast cancer treatment increasingly include the internal mammary chain (IMC). In order to maximise survival benefits of IMC radiotherapy, doses to the heart and lung should be minimised. This dosimetry study compared the ability of three-dimensional conformal radiotherapy, arc therapy and proton beam therapy (PBT) techniques with and without breath-hold to achieve target volume constraints while minimising dose to organs at risk (OARs). MATERIALS AND METHODS In 14 patients' datasets, seven IMC radiotherapy techniques were compared: wide tangent (WT) three-dimensional conformal radiotherapy, volumetric-modulated arc therapy (VMAT) and PBT, each in voluntary deep inspiratory breath-hold (vDIBH) and free breathing (FB), and tomotherapy in FB only. Target volume coverage and OAR doses were measured for each technique. These were compared using a one-way ANOVA with all pairwise comparisons tested using Bonferroni's multiple comparisons test, with adjusted P-values ≤ 0.05 indicating statistical significance. RESULTS One hundred per cent of WT(vDIBH), 43% of WT(FB), 100% of VMAT(vDIBH), 86% of VMAT(FB), 100% of tomotherapy FB and 100% of PBT plans in vDIBH and FB passed all mandatory constraints. However, coverage of the IMC with 90% of the prescribed dose was significantly better than all other techniques using VMAT(vDIBH), PBT(vDIBH) and PBT(FB) (mean IMC coverage ± 1 standard deviation = 96.0% ± 4.3, 99.8% ± 0.3 and 99.0% ± 0.2, respectively). The mean heart dose was significantly reduced in vDIBH compared with FB for both the WT (P < 0.0001) and VMAT (P < 0.0001) techniques. There was no advantage in target volume coverage or OAR doses for PBT(vDIBH) compared with PBT(FB). CONCLUSIONS Simple WT radiotherapy delivered in vDIBH achieves satisfactory coverage of the IMC while meeting heart and lung dose constraints. However, where higher isodose coverage is required, VMAT(vDIBH) is the optimal photon technique. The lowest OAR doses are achieved by PBT, in which the use of vDIBH does not improve dose statistics.
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Affiliation(s)
- A Ranger
- The Royal Marsden NHS Foundation Trust, London, UK; The Institute of Cancer Research, London, UK.
| | - A Dunlop
- The Royal Marsden NHS Foundation Trust, London, UK; The Institute of Cancer Research, London, UK
| | - K Hutchinson
- Cambridge University Hospitals NHS Trust, Cambridge, UK
| | - H Convery
- The Royal Marsden NHS Foundation Trust, London, UK; The Institute of Cancer Research, London, UK
| | | | - H Chantler
- Cambridge University Hospitals NHS Trust, Cambridge, UK
| | - N Twyman
- Cambridge University Hospitals NHS Trust, Cambridge, UK
| | - C Rose
- Cambridge University Hospitals NHS Trust, Cambridge, UK
| | - D McQuaid
- The Royal Marsden NHS Foundation Trust, London, UK; The Institute of Cancer Research, London, UK
| | - R A Amos
- University College London, London, UK
| | - C Griffin
- Clinical Trials and Statistics Unit, The Institute of Cancer Research, London, UK
| | - N M deSouza
- The Royal Marsden NHS Foundation Trust, London, UK; The Institute of Cancer Research, London, UK
| | - E Donovan
- CVSSP, University of Surrey, Guildford, UK
| | - E Harris
- The Royal Marsden NHS Foundation Trust, London, UK; The Institute of Cancer Research, London, UK
| | - C E Coles
- University of Cambridge, Cambridge, UK
| | - A Kirby
- The Royal Marsden NHS Foundation Trust, London, UK; The Institute of Cancer Research, London, UK
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Wang X, Zhang X, Li X, Amos RA, Shaitelman SF, Hoffman K, Howell R, Salehpour M, Zhang SX, Sun TL, Smith B, Tereffe W, Perkins GH, Buchholz TA, Strom EA, Woodward WA. Accelerated partial-breast irradiation using intensity-modulated proton radiotherapy: do uncertainties outweigh potential benefits? Br J Radiol 2013; 86:20130176. [PMID: 23728947 PMCID: PMC3755395 DOI: 10.1259/bjr.20130176] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 05/22/2013] [Accepted: 05/29/2013] [Indexed: 11/07/2022] Open
Abstract
OBJECTIVE Passive scattering proton beam (PSPB) radiotherapy for accelerated partial-breast irradiation (APBI) provides superior dosimetry for APBI three-dimensional conformal photon radiotherapy (3DCRT). Here we examine the potential incremental benefit of intensity-modulated proton radiotherapy (IMPT) for APBI and compare its dosimetry with PSPB and 3DCRT. METHODS Two theoretical IMPT plans, TANGENT_PAIR and TANGENT_ENFACE, were created for 11 patients previously treated with 3DCRT APBI and were compared with PSPB and 3DCRT plans for the same CT data sets. The impact of range, motion and set-up uncertainties as well as scanned spot mismatching between fields of IMPT plans was evaluated. RESULTS IMPT plans for APBI were significantly better regarding breast skin sparing (p<0.005) and other normal tissue sparing than 3DCRT plans (p<0.01) with comparable target coverage (p=ns). IMPT plans were statistically better than PSPB plans regarding breast skin (p<0.002) and non-target breast (p<0.007) in higher dose regions but worse or comparable in lower dose regions. IMPT plans using TANGENT_ENFACE were superior to that using TANGENT_PAIR in terms of target coverage (p<0.003) and normal tissue sparing (p<0.05) in low-dose regions. IMPT uncertainties were demonstrated for multiple causes. Qualitative comparison of dose-volume histogram confidence intervals for IMPT suggests that numeric gains may be offset by IMPT uncertainties. CONCLUSION Using current clinical dosimetry, PSPB provides excellent dosimetry compared with 3DCRT with fewer uncertainties compared with IMPT. ADVANCES IN KNOWLEDGE As currently delivered in the clinic, PSPB planning for APBI provides as good or better dosimetry than IMPT with less uncertainty.
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Affiliation(s)
- X Wang
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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Dvorak CA, Schmitz WD, Poon DJ, Pryde DC, Lawson JP, Amos RA, Meyers AI. The Synthesis of Streptogramin Antibiotics: (-)-Griseoviridin and Its C-8 Epimer Financial support has been provided by the National Institutes of Health (NIH). We thank the NIH for financial support of this study and Drs. Russell Linderman, Donald Walker, Ronald Spohn, and Enrico Marcantoni for their assistance in various stages of this effort. Angew Chem Int Ed Engl 2000; 39:1664-1666. [PMID: 10820470 DOI: 10.1002/(sici)1521-3773(20000502)39:9<1664::aid-anie1664>3.0.co;2-#] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- CA Dvorak
- Department of Chemistry, Colorado State University Fort Collins, CO 80523 (USA)
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Dunkirk SG, Gregg SL, Duran LW, Monfils JD, Haapala JE, Marcy JA, Clapper DL, Amos RA, Guire PE. Photochemical coatings for the prevention of bacterial colonization. J Biomater Appl 1991; 6:131-56. [PMID: 1779411 DOI: 10.1177/088532829100600203] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Biomaterials are being used with increasing frequency for tissue substitution. Implantable, prosthetic devices are instrumental in the saving of patients' lives and enhancing the quality of life for many others. However, the greatest barrier to expanding the use of biomedical devices is the high probability of bacterial adherence and proliferation, causing very difficult and often untreatable medical-device centered infections. The difficulty in treating such infections results in great danger to the patient, and usually retrieval of the device with considerable pain and suffering. Clearly, development of processes that make biomedical devices resistant to bacterial adherence and colonization would have widespread application in the field of biomedical technology. A photochemical surface modification process is being investigated as a generic means of applying antimicrobial coatings to biomedical devices. The photochemical process results in covalent immobilization of coatings to all classes of medical device polymers. A discussion of the photochemical surface modification process and preliminary results demonstrating the success of photochemical coatings in formulating microbial-resistant surfaces are presented in this paper.
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Affiliation(s)
- S G Dunkirk
- Department of Biochemistry, North Dakota State University, Fargo 58105
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Richardson RJ, Hupp EW, Amos RA. Changes in creatinine output and the physical condition of college women enrolled in a program of conditioning exercises. J Sports Med Phys Fitness 1968; 8:191-7. [PMID: 5717720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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