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Kurz C, Nijhuis R, Reiner M, Ganswindt U, Thieke C, Belka C, Parodi K, Landry G. Feasibility of automated proton therapy plan adaptation for head and neck tumors using cone beam CT images. Radiat Oncol 2016; 11:64. [PMID: 27129305 PMCID: PMC4851791 DOI: 10.1186/s13014-016-0641-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 04/27/2016] [Indexed: 11/10/2022] Open
Abstract
Background Intensity modulated proton therapy (IMPT) of head and neck (H&N) tumors may benefit from plan adaptation to correct for the dose perturbations caused by weight loss and tumor volume changes observed in these patients. As cone beam CT (CBCT) is increasingly considered in proton therapy, it may be possible to use available CBCT images following intensity correction for plan adaptation. This is the first study exploring IMPT plan adaptation on CBCT images corrected and delineated by deformable image registration of the planning CT (pCT) to the CBCT, yielding a virtual CT (vCT). Methods A Morphons algorithm was used to deform the pCTs and corresponding delineations of 9 H&N cancer patients to a weekly CBCT acquired within ±3 days of a control replanning CT scan (rpCT). The IMPT treatment plans were adapted using the vCT and the adapted and original plans were recalculated on the rpCT for dose/volume parameter evaluation of the impact of adaptation. Results On the rpCT, the adapted plans were equivalent to the original plans in terms of target volumes D95 and V95, but showed a significant reduction of D2 in these volumes. OAR doses were mostly equivalent or reduced. In particular, the adapted plans did not reduce parotid gland Dmean, but the dose to the optical system. For three patients the spinal cord or brain stem received higher, though well below tolerance, maximum dose. Subsequent tightening of the treatment planning constraints for these OARs on new vCT-adapted plans did not degrade target coverage and yielded pCT equivalent plans on the vCT. Conclusions An offline automated procedure to generate an adapted IMPT plan on CBCT images was developed and investigated. When evaluating the adapted plan on a control rpCT we observed reduced D2 in target volumes as major improvement. OAR sparing was only partially improved by the procedure. Despite potential limitations in the accuracy of the vCT approach, an improved quality of the adapted plans could be achieved. Electronic supplementary material The online version of this article (doi:10.1186/s13014-016-0641-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Christopher Kurz
- Department of Radiation Oncology, LMU Munich, Munich, Germany.,Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Reinoud Nijhuis
- Department of Radiation Oncology, LMU Munich, Munich, Germany
| | - Michael Reiner
- Department of Radiation Oncology, LMU Munich, Munich, Germany
| | - Ute Ganswindt
- Department of Radiation Oncology, LMU Munich, Munich, Germany
| | | | - Claus Belka
- Department of Radiation Oncology, LMU Munich, Munich, Germany
| | - Katia Parodi
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Guillaume Landry
- Department of Radiation Oncology, LMU Munich, Munich, Germany. .,Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Munich, Germany.
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van Dijk LV, Steenbakkers RJHM, ten Haken B, van der Laan HP, van ‘t Veld AA, Langendijk JA, Korevaar EW. Robust Intensity Modulated Proton Therapy (IMPT) Increases Estimated Clinical Benefit in Head and Neck Cancer Patients. PLoS One 2016; 11:e0152477. [PMID: 27030987 PMCID: PMC4816406 DOI: 10.1371/journal.pone.0152477] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 03/15/2016] [Indexed: 12/25/2022] Open
Abstract
PURPOSE To compare the clinical benefit of robust optimized Intensity Modulated Proton Therapy (minimax IMPT) with current photon Intensity Modulated Radiation Therapy (IMRT) and PTV-based IMPT for head and neck cancer (HNC) patients. The clinical benefit is quantified in terms of both Normal Tissue Complication Probability (NTCP) and target coverage in the case of setup and range errors. METHODS AND MATERIALS For 10 HNC patients, PTV-based IMRT (7 fields), minimax and PTV-based IMPT (2, 3, 4, 5 and 7 fields) plans were tested on robustness. Robust optimized plans differed from PTV-based plans in that they target the CTV and penalize possible error scenarios, instead of using the static isotropic CTV-PTV margin. Perturbed dose distributions of all plans were acquired by simulating in total 8060 setup (±3.5 mm) and range error (±3%) combinations. NTCP models for xerostomia and dysphagia were used to predict the clinical benefit of IMPT versus IMRT. RESULTS The robustness criterion was met in the IMRT and minimax IMPT plans in all error scenarios, but this was only the case in 1 of 40 PTV-based IMPT plans. Seven (out of 10) patients had relatively large NTCP reductions in minimax IMPT plans compared to IMRT. For these patients, xerostomia and dysphagia NTCP values were reduced by 17.0% (95% CI; 13.0-21.1) and 8.1% (95% CI; 4.9-11.2) on average with minimax IMPT. Increasing the number of fields did not contribute to plan robustness, but improved organ sparing. CONCLUSIONS The estimated clinical benefit in terms of NTCP of robust optimized (minimax) IMPT is greater than that of IMRT and PTV-based IMPT in HNC patients. Furthermore, the target coverage of minimax IMPT plans in the presence of errors was comparable to IMRT plans.
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Affiliation(s)
- Lisanne V. van Dijk
- Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Institute for Biomedical Technology and Technical Medicine (MIRA), University of Twente, Enschede, The Netherlands
- * E-mail:
| | - Roel J. H. M. Steenbakkers
- Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Bennie ten Haken
- Institute for Biomedical Technology and Technical Medicine (MIRA), University of Twente, Enschede, The Netherlands
| | - Hans Paul van der Laan
- Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Aart A. van ‘t Veld
- Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Johannes A. Langendijk
- Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Erik W. Korevaar
- Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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Swisher-McClure S, Teo BKK, Kirk M, Chang C, Lin A. Comparison of Pencil Beam Scanning Proton- and Photon-Based Techniques for Carcinoma of the Parotid. Int J Part Ther 2016; 2:525-532. [PMID: 31772964 DOI: 10.14338/ijpt-15-00005.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 09/16/2015] [Indexed: 11/21/2022] Open
Abstract
Purpose To report the dosimetric advantages of a comparison between pencil beam scanning (PBS) proton therapy versus intensity-modulated radiation therapy (IMRT) for parotid gland cancers. Patients and Methods This was a retrospective, dosimetric comparison of 8 patients who received external beam radiation therapy at our institution between 2009 and 2011. Two separate plans were generated for each patient: 1 IMRT and 1 PBS plan. The prescription dose for each plan was 60 Gy for IMRT and 60 Gy (RBE) for PBS. We measured dose-volume relationships for target volumes and organs at risk with each treatment technique. Dosimetric comparisons for each organ at risk were made by using the Wilcoxon signed rank test. All tests were 2-tailed, with P values < .05 considered statistically significant. Results The mean patient planning target volume was 160.9 cm3 (SD 74.6). Pencil beam scanning, compared to IMRT, significantly reduced the mean dose to the following structures: ipsilateral temporal lobe (2.86 versus 9.59 Gy (RBE), P = .01), oral cavity (0.58 versus 13.48 Gy (RBE), P = .01), mandible (V50: 7.4% versus 12.8%, P = .01), contralateral parotid gland (0.003 versus 4.64 Gy (RBE), P = .01), ipsilateral submandibular gland (16.59 versus 38.94 Gy (RBE), P = .03), and contralateral submandibular gland (0.02 versus 5.34 Gy (RBE), P = .01). Pencil beam scanning also significantly reduced the maximum dose delivered to the brainstem (7.1 versus 30.9 Gy (RBE), P = .01). Conclusion Pencil beam scanning allows for superior normal tissue sparing while still maintaining excellent target coverage in patients with resected parotid gland cancers. These findings suggest that PBS may allow for an improved therapeutic index for these patients. Clinical outcomes with PBS should be evaluated prospectively, with a focus on disease outcomes as well as treatment-related toxicities and patient quality of life.
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Affiliation(s)
- Samuel Swisher-McClure
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Boon-Keng Kevin Teo
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Maura Kirk
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Chang Chang
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Alexander Lin
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Romesser PB, Cahlon O, Scher E, Zhou Y, Berry SL, Rybkin A, Sine KM, Tang S, Sherman EJ, Wong R, Lee NY. Proton beam radiation therapy results in significantly reduced toxicity compared with intensity-modulated radiation therapy for head and neck tumors that require ipsilateral radiation. Radiother Oncol 2016; 118:286-92. [PMID: 26867969 DOI: 10.1016/j.radonc.2015.12.008] [Citation(s) in RCA: 130] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 11/28/2015] [Accepted: 12/18/2015] [Indexed: 11/30/2022]
Abstract
BACKGROUND As proton beam radiation therapy (PBRT) may allow greater normal tissue sparing when compared with intensity-modulated radiation therapy (IMRT), we compared the dosimetry and treatment-related toxicities between patients treated to the ipsilateral head and neck with either PBRT or IMRT. METHODS Between 01/2011 and 03/2014, 41 consecutive patients underwent ipsilateral irradiation for major salivary gland cancer or cutaneous squamous cell carcinoma. The availability of PBRT, during this period, resulted in an immediate shift in practice from IMRT to PBRT, without any change in target delineation. Acute toxicities were assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. RESULTS Twenty-three (56.1%) patients were treated with IMRT and 18 (43.9%) with PBRT. The groups were balanced in terms of baseline, treatment, and target volume characteristics. IMRT plans had a greater median maximum brainstem (29.7 Gy vs. 0.62 Gy (RBE), P < 0.001), maximum spinal cord (36.3 Gy vs. 1.88 Gy (RBE), P < 0.001), mean oral cavity (20.6 Gy vs. 0.94 Gy (RBE), P < 0.001), mean contralateral parotid (1.4 Gy vs. 0.0 Gy (RBE), P<0.001), and mean contralateral submandibular (4.1 Gy vs. 0.0 Gy (RBE), P < 0.001) dose when compared to PBRT plans. PBRT had significantly lower rates of grade 2 or greater acute dysgeusia (5.6% vs. 65.2%, P<0.001), mucositis (16.7% vs. 52.2%, P=0.019), and nausea (11.1% vs. 56.5%, P=0.003). CONCLUSIONS The unique properties of PBRT allow greater normal tissue sparing without sacrificing target coverage when irradiating the ipsilateral head and neck. This dosimetric advantage seemingly translates into lower rates of acute treatment-related toxicity.
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Affiliation(s)
- Paul B Romesser
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Oren Cahlon
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, United States; ProCure Proton Therapy Center, Somerset, United States
| | - Eli Scher
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, United States; Rowan University School of Osteopathic Medicine, Stratford, United States
| | - Ying Zhou
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Sean L Berry
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Alisa Rybkin
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Kevin M Sine
- ProCure Proton Therapy Center, Somerset, United States
| | - Shikui Tang
- ProCure Proton Therapy Center, Somerset, United States
| | - Eric J Sherman
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Richard Wong
- Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Nancy Y Lee
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, United States.
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Doyen J, Falk AT, Floquet V, Hérault J, Hannoun-Lévi JM. Proton beams in cancer treatments: Clinical outcomes and dosimetric comparisons with photon therapy. Cancer Treat Rev 2016; 43:104-12. [PMID: 26827698 DOI: 10.1016/j.ctrv.2015.12.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Revised: 12/24/2015] [Accepted: 12/29/2015] [Indexed: 12/25/2022]
Abstract
PURPOSE To review current evidence of the role of proton therapy (PT) in other tumors than skull base, sinusal/parasinusal, spinal and pediatric tumors; to determine medico-economic aspects raised by PT. MATERIAL AND METHODS A systematic review on Medline was performed with the following keywords: proton therapy, proton beam, protontherapy, cancer; publications with comparison between PT and photon-therapy were also selected. RESULTS In silico studies have shown superiority (better dose delivery to the target and/or to organs at risk) of PT toward photon-therapy in most of thoracic and abdominal malignant tumors. Potential benefits of PT could be: reduction of toxicities (including radiation-induced cancer), increase of tumor control through a dose-escalation approach, hypofractionation. Cost of treatment is always cited as an issue which actually can be managed by a precise patient selection making PT a cost-effective procedure. Comparison plan with photon therapy may be useful to determine the dosimetric and clinical advantages of PT (Normal Tissue Complications Probability). CONCLUSION PT may be associated with a great advantage compared to the best photon-therapies in various types of cancers. Accumulation of clinical data is on-going and will challenge the in silico data analysis. Some indications are associated with strong superiority of PT and may be discussed as a new standard within prospective observational studies.
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Affiliation(s)
- Jérôme Doyen
- Department of Radiation Oncology, Antoine Lacassagne Cancer Center, University of Nice-Sophia, Nice, France
| | - Alexander Tuan Falk
- Department of Radiation Oncology, Antoine Lacassagne Cancer Center, University of Nice-Sophia, Nice, France
| | - Vincent Floquet
- Department of Radiation Oncology, Antoine Lacassagne Cancer Center, University of Nice-Sophia, Nice, France
| | - Joël Hérault
- Department of Radiation Oncology, Antoine Lacassagne Cancer Center, University of Nice-Sophia, Nice, France
| | - Jean-Michel Hannoun-Lévi
- Department of Radiation Oncology, Antoine Lacassagne Cancer Center, University of Nice-Sophia, Nice, France.
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Lewis GD, Holliday EB, Kocak-Uzel E, Hernandez M, Garden AS, Rosenthal DI, Frank SJ. Intensity-modulated proton therapy for nasopharyngeal carcinoma: Decreased radiation dose to normal structures and encouraging clinical outcomes. Head Neck 2015; 38 Suppl 1:E1886-95. [DOI: 10.1002/hed.24341] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2015] [Indexed: 12/25/2022] Open
Affiliation(s)
- Gary D. Lewis
- Department of Radiation Oncology; University of Texas MD Anderson Cancer Center; Houston Texas
| | - Emma B. Holliday
- Department of Radiation Oncology; University of Texas MD Anderson Cancer Center; Houston Texas
| | - Esengul Kocak-Uzel
- Department of Radiation Oncology; University of Texas MD Anderson Cancer Center; Houston Texas
- Department of Radiotherapy; Beykent University; Istanbul Turkey
| | - Mike Hernandez
- Department of Biostatistics; University of Texas MD Anderson Cancer Center; Houston Texas
| | - Adam S. Garden
- Department of Radiation Oncology; University of Texas MD Anderson Cancer Center; Houston Texas
| | - David I. Rosenthal
- Department of Radiation Oncology; University of Texas MD Anderson Cancer Center; Houston Texas
| | - Steven J. Frank
- Department of Radiation Oncology; University of Texas MD Anderson Cancer Center; Houston Texas
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Abstract
External beam radiation therapy is a commonly utilized treatment modality in the management of head and neck cancer. Given the close proximity of disease to critical normal tissues and structures, the delivery of external beam radiation therapy can result in severe acute and late toxicities, even when delivered with advanced photon-based techniques, such as intensity-modulated radiation therapy. The unique physical characteristics of protons make it a promising option in the treatment of advanced head and neck cancer, with the potential to improve sparing of normal tissues and/or safely escalate radiation doses. Clinical implementation will require the continued development of advanced techniques such as intensity-modulated proton therapy, using pencil beam scanning, as well as rigorous methods of quality assurance and adaptive techniques to accurately adjust to changes in anatomy due to disease response. Ultimately, the widespread adaptation and implementation of proton therapy for head and neck cancer will require direct, prospective comparisons to standard techniques such as intensity-modulated radiation therapy, with a focus on measures such as toxicity, disease control, and quality of life.
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Effectiveness and toxicity of helical tomotherapy for patients with locally recurrent nasopharyngeal carcinoma. Clin Transl Oncol 2015; 17:925-31. [DOI: 10.1007/s12094-015-1328-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 06/09/2015] [Indexed: 10/23/2022]
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Tangsriwong K, Kirk M, Both S, Lin A. Potential Impact of Daily Setup Variation on Pencil-Beam Scanning for Head and Neck Cancer. Int J Part Ther 2015. [DOI: 10.14338/ijpt-15-00007.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Holliday EB, Garden AS, Rosenthal DI, Fuller CD, Morrison WH, Gunn GB, Phan J, Beadle BM, Zhu XR, Zhang X, Hanna E, Glisson BS, Hutcheson KA, El-Naggar AK, Hong JH, Hung TM, Uzel EK, Lewis G, Frank SJ. Proton Therapy Reduces Treatment-Related Toxicities for Patients with Nasopharyngeal Cancer: A Case-Match Control Study of Intensity-Modulated Proton Therapy and Intensity-Modulated Photon Therapy. Int J Part Ther 2015. [DOI: 10.14338/ijpt-15-00011.1] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Reducing the cost of proton radiation therapy: the feasibility of a streamlined treatment technique for prostate cancer. Cancers (Basel) 2015; 7:688-705. [PMID: 25920039 PMCID: PMC4491679 DOI: 10.3390/cancers7020688] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 04/03/2015] [Accepted: 04/15/2015] [Indexed: 01/05/2023] Open
Abstract
Proton radiation therapy is an effective modality for cancer treatments, but the cost of proton therapy is much higher compared to conventional radiotherapy and this presents a formidable barrier to most clinical practices that wish to offer proton therapy. Little attention in literature has been paid to the costs associated with collimators, range compensators and hypofractionation. The objective of this study was to evaluate the feasibility of cost-saving modifications to the present standard of care for proton treatments for prostate cancer. In particular, we quantified the dosimetric impact of a treatment technique in which custom fabricated collimators were replaced with a multileaf collimator (MLC) and the custom range compensators (RC) were eliminated. The dosimetric impacts of these modifications were assessed for 10 patients with a commercial treatment planning system (TPS) and confirmed with corresponding Monte Carlo simulations. We assessed the impact on lifetime risks of radiogenic second cancers using detailed dose reconstructions and predictive dose-risk models based on epidemiologic data. We also performed illustrative calculations, using an isoeffect model, to examine the potential for hypofractionation. Specifically, we bracketed plausible intervals of proton fraction size and total treatment dose that were equivalent to a conventional photon treatment of 79.2 Gy in 44 fractions. Our results revealed that eliminating the RC and using an MLC had negligible effect on predicted dose distributions and second cancer risks. Even modest hypofractionation strategies can yield substantial cost savings. Together, our results suggest that it is feasible to modify the standard of care to increase treatment efficiency, reduce treatment costs to patients and insurers, while preserving high treatment quality.
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Jakobi A, Bandurska-Luque A, Stützer K, Haase R, Löck S, Wack LJ, Mönnich D, Thorwarth D, Perez D, Lühr A, Zips D, Krause M, Baumann M, Perrin R, Richter C. Identification of Patient Benefit From Proton Therapy for Advanced Head and Neck Cancer Patients Based on Individual and Subgroup Normal Tissue Complication Probability Analysis. Int J Radiat Oncol Biol Phys 2015; 92:1165-1174. [PMID: 26194685 DOI: 10.1016/j.ijrobp.2015.04.031] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 04/13/2015] [Accepted: 04/17/2015] [Indexed: 12/25/2022]
Abstract
PURPOSE The purpose of this study was to determine, by treatment plan comparison along with normal tissue complication probability (NTCP) modeling, whether a subpopulation of patients with head and neck squamous cell carcinoma (HNSCC) could be identified that would gain substantial benefit from proton therapy in terms of NTCP. METHODS AND MATERIALS For 45 HNSCC patients, intensity modulated radiation therapy (IMRT) was compared to intensity modulated proton therapy (IMPT). Physical dose distributions were evaluated as well as the resulting NTCP values, using modern models for acute mucositis, xerostomia, aspiration, dysphagia, laryngeal edema, and trismus. Patient subgroups were defined based on primary tumor location. RESULTS Generally, IMPT reduced the NTCP values while keeping similar target coverage for all patients. Subgroup analyses revealed a higher individual reduction of swallowing-related side effects by IMPT for patients with tumors in the upper head and neck area, whereas the risk reduction of acute mucositis was more pronounced in patients with tumors in the larynx region. More patients with tumors in the upper head and neck area had a reduction in NTCP of more than 10%. CONCLUSIONS Subgrouping can help to identify patients who may benefit more than others from the use of IMPT and, thus, can be a useful tool for a preselection of patients in the clinic where there are limited PT resources. Because the individual benefit differs within a subgroup, the relative merits should additionally be evaluated by individual treatment plan comparisons.
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Affiliation(s)
- Annika Jakobi
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.
| | - Anna Bandurska-Luque
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Department of Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Kristin Stützer
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Robert Haase
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Steffen Löck
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Linda-Jacqueline Wack
- Section for Biomedical Physics, University Hospital for Radiation Oncology, Eberhard Karls Universät Tübingen, Germany
| | - David Mönnich
- Section for Biomedical Physics, University Hospital for Radiation Oncology, Eberhard Karls Universät Tübingen, Germany; German Cancer Research Center, Heidelberg, Germany; German Cancer Consortium, Tübingen, Germany
| | - Daniela Thorwarth
- Section for Biomedical Physics, University Hospital for Radiation Oncology, Eberhard Karls Universät Tübingen, Germany
| | - Damien Perez
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; German Cancer Research Center, Heidelberg, Germany; German Cancer Consortium, Dresden, Germany
| | - Armin Lühr
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; German Cancer Research Center, Heidelberg, Germany; German Cancer Consortium, Dresden, Germany
| | - Daniel Zips
- Department of Radiation Oncology, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Mechthild Krause
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Department of Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; German Cancer Research Center, Heidelberg, Germany; German Cancer Consortium, Dresden, Germany; Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology, Dresden, Germany
| | - Michael Baumann
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Department of Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; German Cancer Research Center, Heidelberg, Germany; German Cancer Consortium, Dresden, Germany; Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology, Dresden, Germany
| | - Rosalind Perrin
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Paul Scherrer Institute, Villigen, Switzerland
| | - Christian Richter
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Department of Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; German Cancer Research Center, Heidelberg, Germany; German Cancer Consortium, Dresden, Germany; Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology, Dresden, Germany
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Doyen J, Bondiau PY, Bénézéry K, Chand MÈ, Thariat J, Leysalle A, Gérard JP, Habrand JL, Hannoun-Lévi JM. [Current situation and perspectives of proton therapy]. Cancer Radiother 2015; 19:211-9; quiz 231-2, 235. [PMID: 25840776 DOI: 10.1016/j.canrad.2014.12.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 12/26/2014] [Indexed: 12/25/2022]
Abstract
Proton beam therapy is indicated as a treatment for some rare tumours and paediatric tumours because the technique allows a good local control with minimal toxicity; the growing number of centres that use proton beam therapy is associated with an increase of dosimetric and clinical data for other malignant tumours as well. This paper reviews potential indications of proton beam therapy. A systematic review on Medline was performed with the following keywords proton beam therapy, cancer, heavy particle, charged particle. No phase III trial has been published using proton beam therapy in comparison with the best photon therapy, but numerous retrospective and dosimetric studies have revealed an advantage of proton beam therapy compared to photons, above all in tumours next to parallel organs at risk (thoracic and abdominal tumours). This could be accompanied with a better safety profile and/or a better tumoural control; numerous phase 0, I, II, III and IV studies are ongoing to examine these hypotheses in more common cancers. Use of proton beam therapy is growing for common cancers within clinical trials but some indications could be applied sooner since in silico analysis showed major advantages with this technique.
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Affiliation(s)
- J Doyen
- Pôle de radiothérapie, centre Antoine-Lacassagne, université Nice-Sophia, 33, avenue de Valombrose, 06000 Nice, France
| | - P-Y Bondiau
- Pôle de radiothérapie, centre Antoine-Lacassagne, université Nice-Sophia, 33, avenue de Valombrose, 06000 Nice, France
| | - K Bénézéry
- Pôle de radiothérapie, centre Antoine-Lacassagne, université Nice-Sophia, 33, avenue de Valombrose, 06000 Nice, France
| | - M-È Chand
- Pôle de radiothérapie, centre Antoine-Lacassagne, université Nice-Sophia, 33, avenue de Valombrose, 06000 Nice, France
| | - J Thariat
- Pôle de radiothérapie, centre Antoine-Lacassagne, université Nice-Sophia, 33, avenue de Valombrose, 06000 Nice, France
| | - A Leysalle
- Pôle de radiothérapie, centre Antoine-Lacassagne, université Nice-Sophia, 33, avenue de Valombrose, 06000 Nice, France
| | - J-P Gérard
- Pôle de radiothérapie, centre Antoine-Lacassagne, université Nice-Sophia, 33, avenue de Valombrose, 06000 Nice, France
| | - J-L Habrand
- Département de radiothérapie, centre François-Baclesse, 3, avenue du Général-Harris, 14076 Caen cedex 05, France
| | - J-M Hannoun-Lévi
- Pôle de radiothérapie, centre Antoine-Lacassagne, université Nice-Sophia, 33, avenue de Valombrose, 06000 Nice, France.
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Characterization of volume and shape modifications of PET-positive nodes during Tomotherapy for head and neck cancer as assessed by MVCTs. Radiother Oncol 2015; 115:50-5. [DOI: 10.1016/j.radonc.2015.01.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Revised: 11/20/2014] [Accepted: 01/24/2015] [Indexed: 11/21/2022]
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Frank SJ, Cox JD, Gillin M, Mohan R, Garden AS, Rosenthal DI, Gunn GB, Weber RS, Kies MS, Lewin JS, Munsell MF, Palmer MB, Sahoo N, Zhang X, Liu W, Zhu XR. Multifield optimization intensity modulated proton therapy for head and neck tumors: a translation to practice. Int J Radiat Oncol Biol Phys 2014; 89:846-53. [PMID: 24867532 PMCID: PMC4171724 DOI: 10.1016/j.ijrobp.2014.04.019] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Revised: 03/06/2014] [Accepted: 04/11/2014] [Indexed: 12/30/2022]
Abstract
BACKGROUND We report the first clinical experience and toxicity of multifield optimization (MFO) intensity modulated proton therapy (IMPT) for patients with head and neck tumors. METHODS AND MATERIALS Fifteen consecutive patients with head and neck cancer underwent MFO-IMPT with active scanning beam proton therapy. Patients with squamous cell carcinoma (SCC) had comprehensive treatment extending from the base of the skull to the clavicle. The doses for chemoradiation therapy and radiation therapy alone were 70 Gy and 66 Gy, respectively. The robustness of each treatment plan was also analyzed to evaluate sensitivity to uncertainties associated with variations in patient setup and the effect of uncertainties with proton beam range in patients. Proton beam energies during treatment ranged from 72.5 to 221.8 MeV. Spot sizes varied depending on the beam energy and depth of the target, and the scanning nozzle delivered the spot scanning treatment "spot by spot" and "layer by layer." RESULTS Ten patients presented with SCC and 5 with adenoid cystic carcinoma. All 15 patients were able to complete treatment with MFO-IMPT, with no need for treatment breaks and no hospitalizations. There were no treatment-related deaths, and with a median follow-up time of 28 months (range, 20-35 months), the overall clinical complete response rate was 93.3% (95% confidence interval, 68.1%-99.8%). Xerostomia occurred in all 15 patients as follows: grade 1 in 10 patients, grade 2 in 4 patients, and grade 3 in 1 patient. Mucositis within the planning target volumes was seen during the treatment of all patients: grade 1 in 1 patient, grade 2 in 8 patients, and grade 3 in 6 patients. No patient experienced grade 2 or higher anterior oral mucositis. CONCLUSIONS To our knowledge, this is the first clinical report of MFO-IMPT for head and neck tumors. Early clinical outcomes are encouraging and warrant further investigation of proton therapy in prospective clinical trials.
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Affiliation(s)
- Steven J Frank
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
| | - James D Cox
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Michael Gillin
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Radhe Mohan
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Adam S Garden
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - David I Rosenthal
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - G Brandon Gunn
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Randal S Weber
- Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Merrill S Kies
- Department of Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Jan S Lewin
- Department of Head and Neck Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Mark F Munsell
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Matthew B Palmer
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Narayan Sahoo
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Xiaodong Zhang
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Wei Liu
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - X Ronald Zhu
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas
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Holliday EB, Frank SJ. Proton radiation therapy for head and neck cancer: a review of the clinical experience to date. Int J Radiat Oncol Biol Phys 2014; 89:292-302. [PMID: 24837890 DOI: 10.1016/j.ijrobp.2014.02.029] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 02/13/2014] [Accepted: 02/20/2014] [Indexed: 02/03/2023]
Abstract
Proton beam radiation has been used for cancer treatment since the 1950s, but recent increasing interest in this form of therapy and the construction of hospital-based and clinic-based facilities for its delivery have greatly increased both the number of patients and the variety of tumors being treated with proton therapy. The mass of proton particles and their unique physical properties (ie, the Bragg peak) allow proton therapy to spare normal tissues distal to the tumor target from incidental irradiation. Initial observations show that proton therapy is particularly useful for treating tumors in challenging locations close to nontarget critical structures. Specifically, improvements in local control outcomes for patients with chordoma, chonodrosarcoma, and tumors in the sinonasal regions have been reported in series using proton. Improved local control and survival outcomes for patients with cancer of the head and neck region have also been seen with the advent of improvements in better imaging and multimodality therapy comprising surgery, radiation therapy, and chemotherapy. However, aggressive local therapy in the proximity of critical normal structures to tumors in the head and neck region may produce debilitating early and late toxic effects. Great interest has been expressed in evaluating whether proton therapy can improve outcomes, especially early and late toxicity, when used in the treatment of head and neck malignancies. This review summarizes the progress made to date in addressing this question.
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Affiliation(s)
- Emma B Holliday
- Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Steven J Frank
- Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
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Yoon HI, Lee IJ, Han KH, Seong J. Improved oncologic outcomes with image-guided intensity-modulated radiation therapy using helical tomotherapy in locally advanced hepatocellular carcinoma. J Cancer Res Clin Oncol 2014; 140:1595-605. [PMID: 24809934 DOI: 10.1007/s00432-014-1697-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 04/24/2014] [Indexed: 01/12/2023]
Abstract
AIM To investigate whether image-guided intensity-modulated radiation therapy (IG-IMRT) improves survival in hepatocellular carcinoma (HCC) relative to 3-dimensional conformal radiotherapy (3D-CRT). METHODS Between 2006 and 2011, 187 HCC patients treated with definitive RT were reviewed. Median age was 53(range 51-83). All patients were stage III or IV-A. Concurrent chemoradiation was received by 178 patients (95.2 %). Overall actuarial survival (OS), progression-free survival (PFS), and infield-failure-free survival (IFFS) analyses were performed by Kaplan-Meier method. A Cox proportional hazards model was used for univariate and multivariate analysis. Pearson's chi-square test or Fisher's exact test was used to compare patient characteristics and treatment-related toxicity between the groups. RESULTS Sixty-five patients were treated with IG-IMRT and 122 patients with 3D-CRT. No significant differences were seen between the groups for all patient characteristics. IG-IMRT delivered higher doses than 3D-CRT (median biological effective dose 62.5 vs 53.1 Gy, P < 0.001). IG-IMRT showed significantly higher 3-year OS (33.4 vs 13.5 %, P < 0.001), PFS (11.1 vs 6.0 %, P = 0.004), and IFFS (46.8 vs 28.2 %, P = 0.007) than 3D-CRT. On univariate and multivariate analysis, RT modality was significant prognostic factor for OS (HR 2.18; 95 % CI 1.45-3.25; P < 0.001), PFS (HR 1.64; 95 % CI 1.17-2.29; P = 0.004). There was no significant difference between the two modalities for radiation-induced liver disease (P = 0.716). CONCLUSION Our findings suggest that IG-IMRT could be an effective treatment that provides survival benefit without increasing severe toxicity in locally advanced HCC.
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Affiliation(s)
- Hong In Yoon
- Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University Health System, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Republic of Korea
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Vernat SS, Ali D, Messina C, Pommier P, Dussart S, Puyraveau M, Viard R, Lacornerie T, Lisbona A, Fenoglietto P, Mazurier J, Garcia R, Hangard G, Zefkili S, Makovicka L, Giraud P. Intensity Modulated Arc Therapy in Bilaterally Irradiated Head and Neck Cancer: A Comparative and Prospective Multicenter Planning Study. Cancer Invest 2014; 32:159-67. [DOI: 10.3109/07357907.2014.889705] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Farace P, Piras S, Porru S, Massazza F, Fadda G, Solla I, Piras D, Deidda MA, Amichetti M, Possanzini M. Preventive sparing of spinal cord and brain stem in the initial irradiation of locally advanced head and neck cancers. J Appl Clin Med Phys 2014; 15:4399. [PMID: 24423836 PMCID: PMC5711237 DOI: 10.1120/jacmp.v15i1.4399] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2013] [Revised: 10/02/2013] [Accepted: 08/30/2013] [Indexed: 11/23/2022] Open
Abstract
Since reirradiation in recurrent head and neck patients is limited by previous treatment, a marked reduction of maximum doses to spinal cord and brain stem was investigated in the initial irradiation of stage III/IV head and neck cancers. Eighteen patients were planned by simultaneous integrated boost, prescribing 69.3 Gy to PTV1 and 56.1 Gy to PTV2. Nine 6 MV coplanar photon beams at equispaced gantry angles were chosen for each patient. Step‐and‐shoot IMRT was calculated by direct machine parameter optimization, with the maximum number of segments limited to 80. In the standard plan, optimization considered organs at risk (OAR), dose conformity, maximum dose <45 Gy to spinal cord and <50 Gy to brain stem. In the sparing plans, a marked reduction to spinal cord and brain stem were investigated, with/without changes in dose conformity. In the sparing plans, the maximum doses to spinal cord and brain stem were reduced from the initial values (43.5±2.2 Gy and 36.7±14.0 Gy), without significant changes on the other OARs. A marked difference (−15.9±1.9 Gy and −10.1±5.7 Gy) was obtained at the expense of a small difference (−1.3%±0.9%) from initial PTV195% coverage (96.6%±0.9%). Similar difference (−15.7±2.2 Gy and −10.2±6.1 Gy) was obtained compromising dose conformity, but unaffecting PTV195% and with negligible decrease in PTV295% (−0.3%±0.3% from the initial 98.3%±0.8%). A marked spinal cord and brain stem preventive sparing was feasible at the expense of a decrease in dose conformity or slightly compromising target coverage. A sparing should be recommended in highly recurrent tumors, to make potential reirradiation safer. PACS number: 87.55.D
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Liu W, Frank SJ, Li X, Li Y, Park PC, Dong L, Ronald Zhu X, Mohan R. Effectiveness of robust optimization in intensity-modulated proton therapy planning for head and neck cancers. Med Phys 2013; 40:051711. [PMID: 23635259 DOI: 10.1118/1.4801899] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Intensity-modulated proton therapy (IMPT) is highly sensitive to uncertainties in beam range and patient setup. Conventionally, these uncertainties are dealt using geometrically expanded planning target volume (PTV). In this paper, the authors evaluated a robust optimization method that deals with the uncertainties directly during the spot weight optimization to ensure clinical target volume (CTV) coverage without using PTV. The authors compared the two methods for a population of head and neck (H&N) cancer patients. METHODS Two sets of IMPT plans were generated for 14 H&N cases, one being PTV-based conventionally optimized and the other CTV-based robustly optimized. For the PTV-based conventionally optimized plans, the uncertainties are accounted for by expanding CTV to PTV via margins and delivering the prescribed dose to PTV. For the CTV-based robustly optimized plans, spot weight optimization was guided to reduce the discrepancy in doses under extreme setup and range uncertainties directly, while delivering the prescribed dose to CTV rather than PTV. For each of these plans, the authors calculated dose distributions under various uncertainty settings. The root-mean-square dose (RMSD) for each voxel was computed and the area under the RMSD-volume histogram curves (AUC) was used to relatively compare plan robustness. Data derived from the dose volume histogram in the worst-case and nominal doses were used to evaluate the plan optimality. Then the plan evaluation metrics were averaged over the 14 cases and were compared with two-sided paired t tests. RESULTS CTV-based robust optimization led to more robust (i.e., smaller AUCs) plans for both targets and organs. Under the worst-case scenario and the nominal scenario, CTV-based robustly optimized plans showed better target coverage (i.e., greater D95%), improved dose homogeneity (i.e., smaller D5% - D95%), and lower or equivalent dose to organs at risk. CONCLUSIONS CTV-based robust optimization provided significantly more robust dose distributions to targets and organs than PTV-based conventional optimization in H&N using IMPT. Eliminating the use of PTV and planning directly based on CTV provided better or equivalent normal tissue sparing.
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Affiliation(s)
- Wei Liu
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.
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Liu W, Frank SJ, Li X, Li Y, Zhu RX, Mohan R. PTV-based IMPT optimization incorporating planning risk volumes vs robust optimization. Med Phys 2013; 40:021709. [PMID: 23387732 DOI: 10.1118/1.4774363] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Robust optimization leads to intensity-modulated proton therapy (IMPT) plans that are less sensitive to uncertainties and superior in terms of organs-at-risk (OARs) sparing, target dose coverage, and homogeneity compared to planning target volume (PTV)-based optimized plans. Robust optimization incorporates setup and range uncertainties, which implicitly adds margins to both targets and OARs and is also able to compensate for perturbations in dose distributions within targets and OARs caused by uncertainties. In contrast, the traditional PTV-based optimization considers only setup uncertainties and adds a margin only to targets but no margins to the OARs. It also ignores range uncertainty. The purpose of this work is to determine if robustly optimized plans are superior to PTV-based plans simply because the latter do not assign margins to OARs during optimization. METHODS The authors retrospectively selected from their institutional database five patients with head and neck (H&N) cancer and one with prostate cancer for this analysis. Using their original images and prescriptions, the authors created new IMPT plans using three methods: PTV-based optimization, optimization based on the PTV and planning risk volumes (PRVs) (i.e., "PTV+PRV-based optimization"), and robust optimization using the "worst-case" dose distribution. The PRVs were generated by uniformly expanding OARs by 3 mm for the H&N cases and 5 mm for the prostate case. The dose-volume histograms (DVHs) from the worst-case dose distributions were used to assess and compare plan quality. Families of DVHs for each uncertainty for all structures of interest were plotted along with the nominal DVHs. The width of the "bands" of DVHs was used to quantify the plan sensitivity to uncertainty. RESULTS Compared with conventional PTV-based and PTV+PRV-based planning, robust optimization led to a smaller bandwidth for the targets in the face of uncertainties {clinical target volume [CTV] bandwidth: 0.59 [robust], 3.53 [PTV+PRV], and 3.53 [PTV] Gy (RBE)}. It also resulted in higher doses to 95% of the CTV {D(95%): 60.8 [robust] vs 59.3 [PTV+PRV] vs 59.6 [PTV] Gy (RBE)}, smaller D(5%) (doses to 5% of the CTV) minus D(95%) {D(5%) - D(95%): 13.2 [robust] vs 17.5 [PTV+PRV] vs 17.2 [PTV] Gy (RBE)}. At the same time, the robust optimization method irradiated OARs less {maximum dose to 1 cm(3) of the brainstem: 48.3 [robust] vs 48.8 [PTV+PRV] vs 51.2 [PTV] Gy (RBE); mean dose to the oral cavity: 22.3 [robust] vs 22.9 [PTV+PRV] vs 26.1 [PTV] Gy (RBE); maximum dose to 1% of the normal brain: 66.0 [robust] vs 68.0 [PTV+PRV] vs 69.3 [PTV] Gy (RBE)}. CONCLUSIONS For H&N cases studied, OAR sparing in PTV+PRV-based optimization was inferior compared to robust optimization but was superior compared to PTV-based optimization; however, target dose robustness and homogeneity were comparable in the PTV+PRV-based and PTV-based optimizations. The same pattern held for the prostate case. The authors' data suggest that the superiority of robust optimization is not due simply to its inclusion of margins for OARs, but that this is due mainly to the ability of robust optimization to compensate for perturbations in dose distributions within target volumes and normal tissues caused by uncertainties.
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Affiliation(s)
- Wei Liu
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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van de Water S, Kraan AC, Breedveld S, Schillemans W, Teguh DN, Kooy HM, Madden TM, Heijmen BJM, Hoogeman MS. Improved efficiency of multi-criteria IMPT treatment planning using iterative resampling of randomly placed pencil beams. Phys Med Biol 2013; 58:6969-83. [PMID: 24029721 DOI: 10.1088/0031-9155/58/19/6969] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This study investigates whether 'pencil beam resampling', i.e. iterative selection and weight optimization of randomly placed pencil beams (PBs), reduces optimization time and improves plan quality for multi-criteria optimization in intensity-modulated proton therapy, compared with traditional modes in which PBs are distributed over a regular grid. Resampling consisted of repeatedly performing: (1) random selection of candidate PBs from a very fine grid, (2) inverse multi-criteria optimization, and (3) exclusion of low-weight PBs. The newly selected candidate PBs were added to the PBs in the existing solution, causing the solution to improve with each iteration. Resampling and traditional regular grid planning were implemented into our in-house developed multi-criteria treatment planning system 'Erasmus iCycle'. The system optimizes objectives successively according to their priorities as defined in the so-called 'wish-list'. For five head-and-neck cancer patients and two PB widths (3 and 6 mm sigma at 230 MeV), treatment plans were generated using: (1) resampling, (2) anisotropic regular grids and (3) isotropic regular grids, while using varying sample sizes (resampling) or grid spacings (regular grid). We assessed differences in optimization time (for comparable plan quality) and in plan quality parameters (for comparable optimization time). Resampling reduced optimization time by a factor of 2.8 and 5.6 on average (7.8 and 17.0 at maximum) compared with the use of anisotropic and isotropic grids, respectively. Doses to organs-at-risk were generally reduced when using resampling, with median dose reductions ranging from 0.0 to 3.0 Gy (maximum: 14.3 Gy, relative: 0%-42%) compared with anisotropic grids and from -0.3 to 2.6 Gy (maximum: 11.4 Gy, relative: -4%-19%) compared with isotropic grids. Resampling was especially effective when using thin PBs (3 mm sigma). Resampling plans contained on average fewer PBs, energy layers and protons than anisotropic grid plans and more energy layers and protons than isotropic grid plans. In conclusion, resampling resulted in improved plan quality and in considerable optimization time reduction compared with traditional regular grid planning.
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Affiliation(s)
- S van de Water
- Department of Radiation Oncology, Erasmus MC-Daniel den Hoed Cancer Center, Groene Hilledijk 301, 3075 EA Rotterdam, The Netherlands
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Kandula S, Zhu X, Garden AS, Gillin M, Rosenthal DI, Ang KK, Mohan R, Amin MV, Garcia JA, Wu R, Sahoo N, Frank SJ. Spot-scanning beam proton therapy vs intensity-modulated radiation therapy for ipsilateral head and neck malignancies: a treatment planning comparison. Med Dosim 2013; 38:390-4. [PMID: 23916884 DOI: 10.1016/j.meddos.2013.05.001] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 02/24/2013] [Accepted: 05/01/2013] [Indexed: 11/13/2022]
Abstract
Radiation therapy for head and neck malignancies can have side effects that impede quality of life. Theoretically, proton therapy can reduce treatment-related morbidity by minimizing the dose to critical normal tissues. We evaluated the feasibility of spot-scanning proton therapy for head and neck malignancies and compared dosimetry between those plans and intensity-modulated radiation therapy (IMRT) plans. Plans from 5 patients who had undergone IMRT for primary tumors of the head and neck were used for planning proton therapy. Both sets of plans were prepared using computed tomography (CT) scans with the goals of achieving 100% of the prescribed dose to the clinical target volume (CTV) and 95% to the planning TV (PTV) while maximizing conformity to the PTV. Dose-volume histograms were generated and compared, as were conformity indexes (CIs) to the PTVs and mean doses to the organs at risk (OARs). Both modalities in all cases achieved 100% of the dose to the CTV and 95% to the PTV. Mean PTV CIs were comparable (0.371 IMRT, 0.374 protons, p = 0.953). Mean doses were significantly lower in the proton plans to the contralateral submandibular (638.7 cGy IMRT, 4.3 cGy protons, p = 0.002) and parotid (533.3 cGy IMRT, 48.5 cGy protons, p = 0.003) glands; oral cavity (1760.4 cGy IMRT, 458.9 cGy protons, p = 0.003); spinal cord (2112.4 cGy IMRT, 249.2 cGy protons, p = 0.002); and brainstem (1553.52 cGy IMRT, 166.2 cGy protons, p = 0.005). Proton plans also produced lower maximum doses to the spinal cord (3692.1 cGy IMRT, 2014.8 cGy protons, p = 0.034) and brainstem (3412.1 cGy IMRT, 1387.6 cGy protons, p = 0.005). Normal tissue V10, V30, and V50 values were also significantly lower in the proton plans. We conclude that spot-scanning proton therapy can significantly reduce the integral dose to head and neck critical structures. Prospective studies are underway to determine if this reduced dose translates to improved quality of life.
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Affiliation(s)
- Shravan Kandula
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
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Sasportas LS, Hosford DN, Sodini MA, Waters DJ, Zambricki EA, Barral JK, Graves EE, Brinton TJ, Yock PG, Le QT, Sirjani D. Cost-effectiveness landscape analysis of treatments addressing xerostomia in patients receiving head and neck radiation therapy. Oral Surg Oral Med Oral Pathol Oral Radiol 2013; 116:e37-51. [PMID: 23643579 PMCID: PMC4018820 DOI: 10.1016/j.oooo.2013.02.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 11/30/2012] [Accepted: 02/20/2013] [Indexed: 12/11/2022]
Abstract
Head and neck (H&N) radiation therapy (RT) can induce irreversible damage to the salivary glands thereby causing long-term xerostomia or dry mouth in 68%-85% of the patients. Not only does xerostomia significantly impair patients' quality-of-life (QOL) but it also has important medical sequelae, incurring high medical and dental costs. In this article, we review various measures to assess xerostomia and evaluate current and emerging solutions to address this condition in H&N cancer patients. These solutions typically seek to accomplish 1 of the 4 objectives: (1) to protect the salivary glands during RT, (2) to stimulate the remaining gland function, (3) to treat the symptoms of xerostomia, or (4) to regenerate the salivary glands. For each treatment, we assess its mechanisms of action, efficacy, safety, clinical utilization, and cost. We conclude that intensity-modulated radiation therapy is both the most widely used prevention approach and the most cost-effective existing solution and we highlight novel and promising techniques on the cost-effectiveness landscape.
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Affiliation(s)
- Laura S Sasportas
- Department of Bioengineering, Biodesign Innovation Program, Stanford University, Stanford, CA 94305, USA.
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Van Gestel D, Verellen D, Van De Voorde L, de Ost B, De Kerf G, Vanderveken O, Van Laer C, Van den Weyngaert D, Vermorken JB, Gregoire V. The potential of helical tomotherapy in the treatment of head and neck cancer. Oncologist 2013; 18:697-706. [PMID: 23723331 PMCID: PMC4063397 DOI: 10.1634/theoncologist.2012-0424] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 03/27/2013] [Indexed: 12/28/2022] Open
Abstract
A decade after its first introduction into the clinic, little is known about the clinical impact of helical tomotherapy (HT) on head and neck cancer (HNC) treatment. Therefore, we analyzed the basics of this technique and reviewed the literature regarding HT's potential benefit in HNC. The past two decades have been characterized by a huge technological evolution in photon beam radiotherapy (RT). In HNC, static beam intensity-modulated radiotherapy (IMRT) has shown superiority over three-dimensional conformal RT in terms of xerostomia and is considered the standard of care. However, the next-generation IMRT, the rotational IMRT, has been introduced into the clinic without any evidence of superiority over static beam IMRT other than being substantially faster. Of these rotational techniques, HT is the first system especially developed for IMRT in combination with image-guided RT. HT is particularly promising for the treatment of HNC because its sharp dose gradients maximally spare the many radiosensitive organs at risk nearby. In addition, HT's integrated computed tomography scan assures a very precise dose administration and allows for some adaptive RT. Because HT is specifically developed for IMRT in combination with (integrated) image-guidance, it allows for precise dose distribution ("dose painting"), patient setup, and dose delivery. As such, it is an excellent tool for difficult HNC irradiation. The literature on the clinical results of HT in HNC all show excellent short-term (≤2 years) results with acceptable toxicity profiles. However, properly designed trials are still warranted to further substantiate these results.
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Affiliation(s)
- Dirk Van Gestel
- Department of Radiotherapy, University Radiotherapy Antwerp, Antwerp, Belgium.
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Clemente S, Cozzolino M, Oliviero C, Fiorentino A, Chiumento C, Fusco V. Impact of machines on plan quality: volumetric modulated arc therapy and intensity modulated radiation therapy. Clin Transl Oncol 2013; 16:141-6. [PMID: 23645162 DOI: 10.1007/s12094-013-1049-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 04/18/2013] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate the impact of different machines on plan quality using both intensity modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) techniques. MATERIALS AND METHODS Eight patients with squamous cell carcinoma of the oropharynx were selected at random. Plans were computed for IMRT and VMAT Smart Arc, using Pinnacle TPS for an Elekta (IMRT-E, VMAT-E) and Varian linac (IMRT-V, VMAT-V). A three-dose level prescription was used to deliver 70, 63 and 58.1 Gy to regions of macroscopic, microscopic high- and low-risk disease, respectively. All doses were given in 35 fractions. Comparisons were performed on dose-volume histogram data, monitor units (MU), and delivery time. RESULTS VMAT-E plans resulted slightly MU efficient (-24 % p < 0.05) compared to VMAT-V while IMRT-V shortened delivery time (-19 % p < 0.05) compared to IMRT-E. All the delivery techniques resulted in equivalent target coverage in terms of D(98) % and D(2) %. For VMAT technique, a significant improvement of 7 % in homogeneity index (HI) for PTV58.1 was observed for Varian machine. A slight improvement in OARs sparing was observed with Elekta machine both for IMRT and VMAT techniques. CONCLUSION Similar plan quality was observed for Elekta and Varian linacs, significant differences were observed in delivery efficiency, as MU number and delivery times, in favor of Elekta and Varian, respectively.
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Affiliation(s)
- S Clemente
- Department of Radiation Oncology, IRCCS CROB, Via Padre Pio n.1, 85028, Rionero in Vulture, PZ, Italy,
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Stuschke M, Kaiser A, Abu-Jawad J, Pöttgen C, Levegrün S, Farr J. Re-irradiation of recurrent head and neck carcinomas: comparison of robust intensity modulated proton therapy treatment plans with helical tomotherapy. Radiat Oncol 2013; 8:93. [PMID: 23601204 PMCID: PMC3648492 DOI: 10.1186/1748-717x-8-93] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 04/09/2013] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND To test the hypothesis that the therapeutic ratio of intensity-modulated photon therapy using helical tomotherapy (HT) for retreatment of head and neck carcinomas can be improved by robust intensity-modulated proton therapy (IMPT). METHODS Comparative dose planning with robust IMPT was performed for 7 patients retreated with HT. RESULTS On average, HT yielded dose gradients steeper in a distance ≤ 7.5 mm outside the target (p<0.0001, F-test) and more conformal high dose regions down to the 50% isodose than IMPT. Both methods proved comparably robust against set-up errors of up to 2 mm, and normal tissue exposure was satisfactory. The mean body dose was smaller with IMPT. CONCLUSIONS IMPT was found not to be uniformly superior to HT and the steeper average dose fall-off around the target volume is an argument pro HT under the methodological implementations used. However, looking at single organs at risk, the normal tissue sparing of IMPT can surpass tomotherapy for an individual patient. Therefore, comparative dose planning is recommended, if both methods are available.
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Affiliation(s)
- Martin Stuschke
- Department of Radiotherapy, University Duisburg-Essen, 45147 Essen, Germany
- Westdeutsches Protonentherapiezentrum Essen, 45147 Essen, Germany
| | - Andreas Kaiser
- Westdeutsches Protonentherapiezentrum Essen, 45147 Essen, Germany
| | - Jehad Abu-Jawad
- Department of Radiotherapy, University Duisburg-Essen, 45147 Essen, Germany
| | - Christoph Pöttgen
- Department of Radiotherapy, University Duisburg-Essen, 45147 Essen, Germany
| | - Sabine Levegrün
- Department of Radiotherapy, University Duisburg-Essen, 45147 Essen, Germany
| | - Jonathan Farr
- Westdeutsches Protonentherapiezentrum Essen, 45147 Essen, Germany
- Current address: Department of Radiologic Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA
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79
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Proton beam therapy for malignancy in Bloom syndrome. Strahlenther Onkol 2013; 189:335-8. [DOI: 10.1007/s00066-012-0274-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 11/08/2012] [Indexed: 12/21/2022]
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80
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Zhang L, Chen QY, Liu H, Tang LQ, Mai HQ. Emerging treatment options for nasopharyngeal carcinoma. DRUG DESIGN DEVELOPMENT AND THERAPY 2013; 7:37-52. [PMID: 23403548 PMCID: PMC3565571 DOI: 10.2147/dddt.s30753] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Nasopharyngeal carcinoma is endemic in Asia and is etiologically associated with Epstein–Barr virus. Radiotherapy is the primary treatment modality. The role of systemic therapy has become more prominent. Based on multiple phase III studies and meta-analyses, concurrent cisplatin-based chemoradiotherapy is the current standard of care for locally advanced disease (American Joint Committee on Cancer manual [7th edition] stages II–IVb). The reported failure-free survival rates from phase II trials are encouraging for induction + concurrent chemoradiotherapy. Data from ongoing phase III trials comparing induction + concurrent chemoradiotherapy with concurrent chemoradiotherapy will validate the results of these phase II studies. Intensity-modulated radiotherapy techniques are recommended if the resources are available. Locoregional control exceeding 90% and reduced xerostomia-related toxicities can now be achieved using intensity-modulated radiotherapy, although distant control remains the most pressing research problem. The promising results of targeted therapy and Epstein–Barr virus-specific immunotherapy from early clinical trials should be validated in phase III clinical trials. New technology, more effective and less toxic chemotherapy regimens, and targeted therapy offer new opportunities for treating nasopharyngeal carcinoma.
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Affiliation(s)
- Lu Zhang
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, People's Republic of China
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81
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Dose to the developing dentition during therapeutic irradiation: organ at risk determination and clinical implications. Int J Radiat Oncol Biol Phys 2013; 86:108-13. [PMID: 23332385 DOI: 10.1016/j.ijrobp.2012.11.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 11/26/2012] [Accepted: 11/27/2012] [Indexed: 11/20/2022]
Abstract
PURPOSE Irradiation of pediatric facial structures can cause severe impairment of permanent teeth later in life. We therefore focused on primary and permanent teeth as organs at risk, investigating the ability to identify individual teeth in children and infants and to correlate dose distributions with subsequent dental toxicity. METHODS AND MATERIALS We retrospectively reviewed 14 pediatric patients who received a maximum dose >20 Gy(relative biological effectiveness, RBE) to 1 or more primary or permanent teeth between 2003 and 2009. The patients (aged 1-16 years) received spot-scanning proton therapy with 46 to 66 Gy(RBE) in 23 to 33 daily fractions for a variety of tumors, including rhabdomyosarcoma (n=10), sarcoma (n=2), teratoma (n=1), and carcinoma (n=1). Individual teeth were contoured on axial slices from planning computed tomography (CT) scans. Dose-volume histogram data were retrospectively obtained from total calculated delivered treatments. Dental follow-up information was obtained from external care providers. RESULTS All primary teeth and permanent incisors, canines, premolars, and first and second molars were identifiable on CT scans in all patients as early as 1 year of age. Dose-volume histogram analysis showed wide dose variability, with a median 37 Gy(RBE) per tooth dose range across all individuals, and a median 50 Gy(RBE) intraindividual dose range across all teeth. Dental follow-up revealed absence of significant toxicity in 7 of 10 patients but severe localized toxicity in teeth receiving >20 Gy(RBE) among 3 patients who were all treated at <4 years of age. CONCLUSIONS CT-based assessment of dose distribution to individual teeth is feasible, although delayed calcification may complicate tooth identification in the youngest patients. Patterns of dental dose exposure vary markedly within and among patients, corresponding to rapid dose falloff with protons. Severe localized dental toxicity was observed in a few patients receiving the largest doses of radiation at the youngest ages; however, multiple factors including concurrent chemotherapy confounded the dose-effect relationship. Further studies with larger cohorts and appropriate controls will be required.
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Abstract
In this article, we focus on the current and emerging treatments in nasopharyngeal cancer (NPC). A detailed evolution of the current standard of care, and new techniques and treatment options will be reviewed. Intergroup 0099 established the role for chemoradiotherapy (chemo-RT) in the treatment of nasopharyngeal carcinoma. Multiple randomized Phase III trials have shown the benefit of chemo-RT; however, none of these studies utilized modern radiotherapy (RT) techniques of intensity-modulated radiation therapy (IMRT). IMRT has the ability to deliver high doses of radiation to the target structures while sparing adjacent bystander healthy tissues, and has now become the preferred RT treatment modality. Chemotherapy also has had a shifting paradigm of induction and/or adjuvant chemotherapy combined with RT alone, to the investigation with concurrent chemo-RT. New treatment options including targeted monoclonal antibodies and small molecule tyrosine kinase inhibitors are being studied in NPC. These new biologic therapies have promising in vitro activity for NPC, and emerging clinical studies are beginning to define their role. RT continues to expand its capabilities, and since IMRT and particle therapy, specifically intensity-modulated proton therapy (IMPT), has reports of impressive dosimetric efficacy in-silica. Adaptive RT is attempting to reduce toxicity while maintaining treatment efficacy, and the clinical results are still in their youth. Lastly, Epstein– Barr virus (EBV) DNA has recently been studied for prediction of tumor response and its use as a biomarker is increasingly promising to aid in early detection as well as supplementing the current staging system. RT with or without chemotherapy remains the standard of care for nasopharyngeal carcinoma. Advances in RT technique, timing of chemotherapy, biologically targeted agents, particle therapy, adaptive RT, and the incorporation of EBV DNA as a biomarker may aid in the current and future treatment of nasopharyngeal cancer.
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Affiliation(s)
- Daniel E Spratt
- Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
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83
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Abstract
Management of nasopharyngeal carcinoma is one of the greatest clinical challenges. Appropriate detection is not easy because of its anatomical location; sensitive biomarkers in addition to endoscopic and radiological examinations would be valuable. One useful biomarker (particularly for nonkeratinizing carcinoma) is the plasma level of Epstein-Barr viral deoxyribonucleic acid, and its role as a tool for prognostication and monitoring disease progress is presented. Radiotherapy is the primary treatment modality, and using radiation therapy in combination with chemotherapy is recommended for the treatment of locoregionally advanced tumors. Intensity-modulated radiotherapy techniques with image guidance to ensure setup precision are recommended if resources allow; adaptive replanning should be considered if major deviations from the intended dose distribution occur during the treatment course. Most contemporary series have reported encouraging results, with locoregional control exceeding 90%; the key problem is distant failure. The therapeutic margin is extremely narrow. Although significant reduction of some toxicities (eg, xerostomia) and better quality of life is now achievable especially for early stages, the risk of major late toxicities remains substantial. This review will focus on the primary treatment: the current consensus and controversies in the treatment strategy for different stages, the choice of chemotherapy regimen, and the key factors for improving the therapeutic ratio of radiotherapy will be discussed. Summary of the current achievement and direction for future improvement will be presented.
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84
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Alexander A, Soisson E, Renaud MA, Seuntjens J. Direct aperture optimization for FLEC-based MERT and its application in mixed beam radiotherapy. Med Phys 2012; 39:4820-31. [DOI: 10.1118/1.4736423] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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85
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Lee IJ, Seong J. The optimal selection of radiotherapy treatment for hepatocellular carcinoma. Gut Liver 2012; 6:139-48. [PMID: 22570744 PMCID: PMC3343153 DOI: 10.5009/gnl.2012.6.2.139] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Accepted: 07/18/2011] [Indexed: 12/20/2022] Open
Abstract
The majority of patients who present with hepatocellular carcinoma (HCC) are already at an advanced stage, and the tumors are unresectable. Radiotherapy (RT) technology can safely provide focused high-dose irradiation to these patients. A wide spectrum of RT technologiesis currently available, including internal RT consisting of Yttrium-90 ((90)Y), Iodine-131 ((131)I) anti-ferritin antibody and Homium-199 ((199)Ho) and external RT, such as three-dimensional conformal RT, intensity-modulated RT, helical tomotherapy, stereotactic body RT, and image-guided RT. However, it may be difficult for physicians to understand all of the available options and to select the optimal RT treatment. Physicians frequently query radiation oncologists on the practical indications of RT for managing patients with HCC. According to the Korean Liver Cancer Study Group practice guidelines, RT is considered appropriate for unresectable, locally advanced HCC without extrahepatic metastasis, a Child-Pugh class A or B, and tumors that occupy less than two-thirds of the liver with level II evidence. In this review, we discuss the application of various RT modalities based on disease status and the detailed indications for RT according to the Barcelona Clinic Liver Cancer staging system.
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Affiliation(s)
- Ik Jae Lee
- Department of Radiation Oncology, Yonsei Liver Cancer Clinic, Yonsei University College of Medicine, Seoul, Korea
| | - Jinsil Seong
- Department of Radiation Oncology, Yonsei Liver Cancer Clinic, Yonsei University College of Medicine, Seoul, Korea
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86
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Widesott L, Lomax AJ, Schwarz M. Is there a single spot size and grid for intensity modulated proton therapy? Simulation of head and neck, prostate and mesothelioma cases. Med Phys 2012; 39:1298-308. [DOI: 10.1118/1.3683640] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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87
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van de Water TA, Lomax AJ, Bijl HP, Schilstra C, Hug EB, Langendijk JA. Using a Reduced Spot Size for Intensity-Modulated Proton Therapy Potentially Improves Salivary Gland-Sparing in Oropharyngeal Cancer. Int J Radiat Oncol Biol Phys 2012; 82:e313-9. [DOI: 10.1016/j.ijrobp.2011.05.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 02/27/2011] [Accepted: 05/10/2011] [Indexed: 10/18/2022]
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van der Schaaf A, Xu CJ, van Luijk P, Van't Veld AA, Langendijk JA, Schilstra C. Multivariate modeling of complications with data driven variable selection: guarding against overfitting and effects of data set size. Radiother Oncol 2012; 105:115-21. [PMID: 22264894 DOI: 10.1016/j.radonc.2011.12.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Revised: 11/03/2011] [Accepted: 12/12/2011] [Indexed: 11/27/2022]
Abstract
PURPOSE Multivariate modeling of complications after radiotherapy is frequently used in conjunction with data driven variable selection. This study quantifies the risk of overfitting in a data driven modeling method using bootstrapping for data with typical clinical characteristics, and estimates the minimum amount of data needed to obtain models with relatively high predictive power. MATERIALS AND METHODS To facilitate repeated modeling and cross-validation with independent datasets for the assessment of true predictive power, a method was developed to generate simulated data with statistical properties similar to real clinical data sets. Characteristics of three clinical data sets from radiotherapy treatment of head and neck cancer patients were used to simulate data with set sizes between 50 and 1000 patients. A logistic regression method using bootstrapping and forward variable selection was used for complication modeling, resulting for each simulated data set in a selected number of variables and an estimated predictive power. The true optimal number of variables and true predictive power were calculated using cross-validation with very large independent data sets. RESULTS For all simulated data set sizes the number of variables selected by the bootstrapping method was on average close to the true optimal number of variables, but showed considerable spread. Bootstrapping is more accurate in selecting the optimal number of variables than the AIC and BIC alternatives, but this did not translate into a significant difference of the true predictive power. The true predictive power asymptotically converged toward a maximum predictive power for large data sets, and the estimated predictive power converged toward the true predictive power. More than half of the potential predictive power is gained after approximately 200 samples. Our simulations demonstrated severe overfitting (a predicative power lower than that of predicting 50% probability) in a number of small data sets, in particular in data sets with a low number of events (median: 7, 95th percentile: 32). Recognizing overfitting from an inverted sign of the estimated model coefficients has a limited discriminative value. CONCLUSIONS Despite considerable spread around the optimal number of selected variables, the bootstrapping method is efficient and accurate for sufficiently large data sets, and guards against overfitting for all simulated cases with the exception of some data sets with a particularly low number of events. An appropriate minimum data set size to obtain a model with high predictive power is approximately 200 patients and more than 32 events. With fewer data samples the true predictive power decreases rapidly, and for larger data set sizes the benefit levels off toward an asymptotic maximum predictive power.
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Affiliation(s)
- Arjen van der Schaaf
- Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
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89
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Chatterjee S, Willis N, Locks SM, Mott JH, Kelly CG. Dosimetric and radiobiological comparison of helical tomotherapy, forward-planned intensity-modulated radiotherapy and two-phase conformal plans for radical radiotherapy treatment of head and neck squamous cell carcinomas. Br J Radiol 2011; 84:1083-90. [PMID: 22101580 PMCID: PMC3473826 DOI: 10.1259/bjr/53812025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 08/20/2010] [Accepted: 08/24/2010] [Indexed: 12/25/2022] Open
Abstract
OBJECTIVES The usual radical radiotherapy treatment prescribed for head and neck squamous cell carcinoma (HNSCC) is 70 Gy (in 2 Gy per fraction equivalent) administered to the high-risk target volume (TV). This can be planned using either a forward-planned photon-electron junction technique (2P) or a single-phase (1P) forward-planned technique developed in-house. Alternatively, intensity-modulated radiotherapy (IMRT) techniques, including helical tomotherapy (HT), allow image-guided inversely planned treatments. This study was designed to compare these three planning techniques with regards to TV coverage and the dose received by organs at risk. METHODS We compared the dose-volume histograms and conformity indices (CI) of the three planning processes in five patients with HNSCC. The tumour control probability (TCP), normal tissue complication probability (NTCP) and uncomplicated tumour control probability (UCP) were calculated for each of the 15 plans. In addition, we explored the radiobiological rationality of a dose-escalation strategy. RESULTS The CI for the high-risk clinical TV (CTV1) in the 5 patients were 0.78, 0.76, 0.82, 0.72 and 0.81 when HT was used; 0.58, 0.56, 0.47, 0.35 and 0.60 for the single-phase forward-planned technique and 0.46, 0.36, 0.29, 0.22 and 0.49 for the two-phase technique. The TCP for CTV1 with HT were 79.2%, 85.2%, 81.1%, 83.0% and 53.0%; for single-phase forward-planned technique, 76.5%, 86.9%, 73.4%, 81.8% and 31.8% and for the two-phase technique, 38.2%, 86.2%, 42.7%, 0.0% and 3.4%. Dose escalation using HT confirmed the radiobiological advantage in terms of TCP. CONCLUSION TCP for the single-phase plans was comparable to that of HT plans, whereas that for the two-phase technique was lower. Centres that cannot provide IMRT for the radical treatment of all patients could implement the single-phase technique as standard to attain comparable TCP. However, IMRT produced better UCP, thereby enabling the exploration of dose escalation.
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Affiliation(s)
- S Chatterjee
- Northern Centre for Cancer Care, Freeman Hospital, Newcastle upon Tyne, UK.
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90
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Zhang M, Westerly DC, Mackie TR. Introducing an on-line adaptive procedure for prostate image guided intensity modulate proton therapy. Phys Med Biol 2011; 56:4947-65. [PMID: 21772078 DOI: 10.1088/0031-9155/56/15/019] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
With on-line image guidance (IG), prostate shifts relative to the bony anatomy can be corrected by realigning the patient with respect to the treatment fields. In image guided intensity modulated proton therapy (IG-IMPT), because the proton range is more sensitive to the material it travels through, the realignment may introduce large dose variations. This effect is studied in this work and an on-line adaptive procedure is proposed to restore the planned dose to the target. A 2D anthropomorphic phantom was constructed from a real prostate patient's CT image. Two-field laterally opposing spot 3D-modulation and 24-field full arc distal edge tracking (DET) plans were generated with a prescription of 70 Gy to the planning target volume. For the simulated delivery, we considered two types of procedures: the non-adaptive procedure and the on-line adaptive procedure. In the non-adaptive procedure, only patient realignment to match the prostate location in the planning CT was performed. In the on-line adaptive procedure, on top of the patient realignment, the kinetic energy for each individual proton pencil beam was re-determined from the on-line CT image acquired after the realignment and subsequently used for delivery. Dose distributions were re-calculated for individual fractions for different plans and different delivery procedures. The results show, without adaptive, that both the 3D-modulation and the DET plans experienced delivered dose degradation by having large cold or hot spots in the prostate. The DET plan had worse dose degradation than the 3D-modulation plan. The adaptive procedure effectively restored the planned dose distribution in the DET plan, with delivered prostate D(98%), D(50%) and D(2%) values less than 1% from the prescription. In the 3D-modulation plan, in certain cases the adaptive procedure was not effective to reduce the delivered dose degradation and yield similar results as the non-adaptive procedure. In conclusion, based on this 2D phantom study, by updating the proton pencil beam energy from the on-line image after realignment, this on-line adaptive procedure is necessary and effective for the DET-based IG-IMPT. Without dose re-calculation and re-optimization, it could be easily incorporated into the clinical workflow.
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Affiliation(s)
- M Zhang
- Department of Medical Physics, University of Wisconsin, Madison, WI 53705, USA.
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91
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SmartArc-Based Volumetric Modulated Arc Therapy for Oropharyngeal Cancer: A Dosimetric Comparison With Both Intensity-Modulated Radiation Therapy and Helical Tomotherapy. Int J Radiat Oncol Biol Phys 2011; 80:1248-55. [DOI: 10.1016/j.ijrobp.2010.08.007] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Revised: 07/03/2010] [Accepted: 08/17/2010] [Indexed: 11/18/2022]
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Park PC, Zhu XR, Lee AK, Sahoo N, Melancon AD, Zhang L, Dong L. A beam-specific planning target volume (PTV) design for proton therapy to account for setup and range uncertainties. Int J Radiat Oncol Biol Phys 2011; 82:e329-36. [PMID: 21703781 DOI: 10.1016/j.ijrobp.2011.05.011] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2010] [Revised: 04/19/2011] [Accepted: 05/10/2011] [Indexed: 12/20/2022]
Abstract
PURPOSE To report a method for explicitly designing a planning target volume (PTV) for treatment planning and evaluation in heterogeneous media for passively scattered proton therapy and scanning beam proton therapy using single-field optimization (SFO). METHODS AND MATERIALS A beam-specific PTV (bsPTV) for proton beams was derived by ray-tracing and shifting ray lines to account for tissue misalignment in the presence of setup error or organ motion. Range uncertainties resulting from inaccuracies in computed tomography-based range estimation were calculated for proximal and distal surfaces of the target in the beam direction. The bsPTV was then constructed based on local heterogeneity. The bsPTV thus can be used directly as a planning target as if it were in photon therapy. To test the robustness of the bsPTV, we generated a single-field proton plan in a virtual phantom. Intentional setup and range errors were introduced. Dose coverage to the clinical target volume (CTV) under various simulation conditions was compared between plans designed based on the bsPTV and a conventional PTV. RESULTS The simulated treatment using the bsPTV design performed significantly better than the plan using the conventional PTV in maintaining dose coverage to the CTV. With conventional PTV plans, the minimum coverage to the CTV dropped from 99% to 67% in the presence of setup error, internal motion, and range uncertainty. However, plans using the bsPTV showed minimal drop of target coverage from 99% to 94%. CONCLUSIONS The conventional geometry-based PTV concept used in photon therapy does not work well for proton therapy. We investigated and validated a beam-specific PTV method for designing and evaluating proton plans.
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Affiliation(s)
- Peter C Park
- Medical Physics Program, Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, TX, USA
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93
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Fiorino C, Maggiulli E, Broggi S, Liberini S, Cattaneo GM, Dell'oca I, Faggiano E, Di Muzio N, Calandrino R, Rizzo G. Introducing the Jacobian-volume-histogram of deforming organs: application to parotid shrinkage evaluation. Phys Med Biol 2011; 56:3301-12. [PMID: 21558590 DOI: 10.1088/0031-9155/56/11/008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The Jacobian of the deformation field of elastic registration between images taken during radiotherapy is a measure of inter-fraction local deformation. The histogram of the Jacobian values (Jac) within an organ was introduced (JVH-Jacobian-volume-histogram) and first applied in quantifying parotid shrinkage. MVCTs of 32 patients previously treated with helical tomotherapy for head-neck cancers were collected. Parotid deformation was evaluated through elastic registration between MVCTs taken at the first and last fractions. Jac was calculated for each voxel of all parotids, and integral JVHs were calculated for each parotid; the correlation between the JVH and the planning dose-volume histogram (DVH) was investigated. On average, 82% (±17%) of the voxels shrinks (Jac < 1) and 14% (±17%) shows a local compression >50% (Jac < 0.5). The best correlation between the DVH and the JVH was found between V10 and V15, and Jac < 0.4-0.6 (p < 0.01). The best constraint predicting a higher number of largely compressing voxels (Jac0.5<7.5%, median value) was V15 ≥ 75% (OR: 7.6, p = 0.002). Jac and the JVH are promising tools for scoring/modelling toxicity and for evaluating organ/contour variations with potential applications in adaptive radiotherapy.
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Affiliation(s)
- Claudio Fiorino
- Medical Physics, San Raffaele Scientific Institute, Milano, Italy.
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94
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Liu H, Chang JY. Proton therapy in clinical practice. CHINESE JOURNAL OF CANCER 2011; 30:315-26. [PMID: 21527064 PMCID: PMC4013396 DOI: 10.5732/cjc.010.10529] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Revised: 12/16/2010] [Accepted: 03/23/2011] [Indexed: 11/17/2022]
Abstract
Radiation dose escalation and acceleration improves local control but also increases toxicity. Proton radiation is an emerging therapy for localized cancers that is being sought with increasing frequency by patients. Compared with photon therapy, proton therapy spares more critical structures due to its unique physics. The physical properties of a proton beam make it ideal for clinical applications. By modulating the Bragg peak of protons in energy and time, a conformal radiation dose with or without intensity modulation can be delivered to the target while sparing the surrounding normal tissues. Thus, proton therapy is ideal when organ preservation is a priority. However, protons are more sensitive to organ motion and anatomy changes compared with photons. In this article, we review practical issues of proton therapy, describe its image-guided treatment planning and delivery, discuss clinical outcome for cancer patients, and suggest challenges and the future development of proton therapy.
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Affiliation(s)
- Hui Liu
- Sun Yat-sen University Cancer Center, Guangzhou, Guangdong 510060, P. R. China;
| | - Joe Y. Chang
- Radiation Oncology Department, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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95
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Lee IJ, Seong J, Koom WS, Kim YB, Jeon BC, Kim JH, Han KH. Selection of the Optimal Radiotherapy Technique for Locally Advanced Hepatocellular Carcinoma. Jpn J Clin Oncol 2011; 41:882-9. [DOI: 10.1093/jjco/hyr053] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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96
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van de Water TA, Bijl HP, Schilstra C, Pijls-Johannesma M, Langendijk JA. The potential benefit of radiotherapy with protons in head and neck cancer with respect to normal tissue sparing: a systematic review of literature. Oncologist 2011; 16:366-77. [PMID: 21349950 PMCID: PMC3228110 DOI: 10.1634/theoncologist.2010-0171] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Accepted: 01/07/2011] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Clinical studies concerning head and neck cancer patients treated with protons reporting on radiation-induced side effects are scarce. Therefore, we reviewed the literature regarding the potential benefits of protons compared with the currently used photons in terms of lower doses to normal tissue and the potential for fewer subsequent radiation-induced side effects, with the main focus on in silico planning comparative (ISPC) studies. MATERIALS AND METHODS A literature search was performed by two independent researchers on ISPC studies that included proton-based and photon-based irradiation techniques. RESULTS Initially, 877 papers were retrieved and 14 relevant and eligible ISPC studies were identified and included in this review. Four studies included paranasal sinus cancer cases, three included nasopharyngeal cancer cases, and seven included oropharyngeal, hypopharyngeal, and/or laryngeal cancer cases. Seven studies compared the most sophisticated photon and proton techniques: intensity-modulated photon therapy versus intensity-modulated proton therapy (IMPT). Four studies compared different proton techniques. All studies showed that protons had a lower normal tissue dose, while keeping similar or better target coverage. Two studies found that these lower doses theoretically translated into a significantly lower incidence of salivary dysfunction. CONCLUSION The results of ISPC studies indicate that protons have the potential for a significantly lower normal tissue dose, while keeping similar or better target coverage. Scanned IMPT probably offers the most advantage and will allow for a substantially lower probability of radiation-induced side effects. The results of these ISPC studies should be confirmed in properly designed clinical trials.
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Affiliation(s)
- Tara A van de Water
- Department of Radiation Oncology, University Medical Center Groningen, 9700 RB Groningen, The Netherlands.
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97
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Sher DJ. Cost-effectiveness studies in radiation therapy. Expert Rev Pharmacoecon Outcomes Res 2011; 10:567-82. [PMID: 20950072 DOI: 10.1586/erp.10.51] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The field of radiation therapy has made dramatic technical advances over the past 20 years. 3D conformal radiotherapy, intensity-modulated radiation therapy and proton beam therapy have all been developed in an attempt to improve the therapeutic ratio: higher cure rates with lower toxicity. Unfortunately, although the costs of radiation therapy are certainly increasing, it is unclear whether its clinical benefit has also improved. Cost-effectiveness analyses are designed to formally evaluate the cost of a treatment relative to an associated change in quality-adjusted survival. As the cost of oncologic care is increasing, it is critically important to assess the cost-effectiveness of radiation therapy. This article will describe the issues surrounding the delivery and cost of radiation therapy, and it will summarize the work that has been done to evaluate the use of cost-effectiveness in radiation oncology.
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Affiliation(s)
- David J Sher
- Department of Radiation Oncology & Center for Outcomes and Policy Research, Dana-Farber Cancer Institute, Boston, MA 02115, USA.
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98
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Hill-Kayser CE, Both S, Tochner Z. Proton Therapy: Ever Shifting Sands and the Opportunities and Obligations within. Front Oncol 2011; 1:24. [PMID: 22655235 PMCID: PMC3355860 DOI: 10.3389/fonc.2011.00024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Accepted: 08/11/2011] [Indexed: 12/25/2022] Open
Abstract
Proton therapy is associated with significant benefit in terms of normal tissue sparing and potential radiation dose escalation for many patients with malignant diseases. Due to recognition of these qualities, the availability of this technology is increasing rapidly, both through increased availability of large centers, and with the possibility of smaller, lower cost proton therapy centers. Such expansion is associated with increased opportunity to provide this beneficial technology to larger numbers of patients; however, the importance of careful treatment planning and delivery, deliberate patient selection, rigorous scientific investigation including comparison to other technologies when possible, and mindfulness of ethical issues and cost effectiveness must not be forgotten. The obligation to move forward responsibly rests on the shoulders of radiation oncologists around the world. In this article, we discuss current use of proton therapy worldwide, as well as many of the factors that must be taken into account during rapid expansion of this exciting technology.
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Affiliation(s)
- Christine E Hill-Kayser
- Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania Philadelphia, PA, USA
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99
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Sangalli G, Passoni P, Cattaneo GM, Broggi S, Bettinardi V, Reni M, Slim N, Muzio ND, Calandrino R. Planning design of locally advanced pancreatic carcinoma using 4DCT and IMRT/IGRT technologies. Acta Oncol 2011; 50:72-80. [PMID: 20482224 DOI: 10.3109/0284186x.2010.484425] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND AND PURPOSE to study the impact of the 4DCT imaging technique on radiotherapy planning for pancreatic carcinoma. To evaluate the possibility of IMRT/IGRT to increase the dose to PTV subvolume. MATERIAL AND METHODS contrast-enhanced 4DCT scans of 15 patients (PTs) with unresectable pancreatic cancer were acquired. A 4DCT based PTV (4D-PTV) was created by the convolution of contours and then expanded for geometric uncertainties; a standard PTV (STD-PTV) was derived from a single CTV plus conventional margins. Two 3D conformal treatment (3DCRT) plans and one Helical Tomotherapy (HT) plan were generated with a prescription of 60 Gy. Regarding the 3DCRT plans, the 4D-PTV was considered as the target volume for one, and the STD-PTV for the other; the HT plans were performed only for 4D-PTV. Twelve of 15 PTs were admitted to a Phase I hypofractionated study (15 fractions). The prescribed dose was 44.25 Gy to the 4D-PTV and the PTV subvolume around vascular involvement was boosted from 50 to 55 Gy; before treatment, daily patient position was corrected using MVCT. RESULTS 4D-PTVs were smaller than STD-PTVs with a volume reduction equal to 37%. 3DCRT plans on 4D-PTV showed a significant sparing of most OARs, the use of IMRT allowed a further significant dose reduction. In the Phase I study the PTV subvolume received up to 55 Gy with modest increase in dose to OARs. CONCLUSIONS the 4DCT procedure decreases the overlap between PTV and OARs. HT technique, compared with 3DCRT, allows efficient dose sparing in particular for the duodenum. The IMRT/IGRT approach allows a safe dose escalation to PTV subvolume.
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Affiliation(s)
- Giulia Sangalli
- Medical Physics Department, San Raffaele Scientific Institute, Milan, Italy
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100
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Vissink A, Mitchell JB, Baum BJ, Limesand KH, Jensen SB, Fox PC, Elting LS, Langendijk JA, Coppes RP, Reyland ME. Clinical management of salivary gland hypofunction and xerostomia in head-and-neck cancer patients: successes and barriers. Int J Radiat Oncol Biol Phys 2010; 78:983-91. [PMID: 20970030 DOI: 10.1016/j.ijrobp.2010.06.052] [Citation(s) in RCA: 224] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Revised: 06/12/2010] [Accepted: 06/20/2010] [Indexed: 12/22/2022]
Abstract
The most significant long-term complication of radiotherapy in the head-and-neck region is hyposalivation and its related complaints, particularily xerostomia. This review addresses the pathophysiology underlying irradiation damage to salivary gland tissue, the consequences of radiation injury, and issues contributing to the clinical management of salivary gland hypofunction and xerostomia. These include ways to (1) prevent or minimize radiation injury of salivary gland tissue, (2) manage radiation-induced hyposalivation and xerostomia, and (3) restore the function of salivary gland tissue damaged by radiotherapy.
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Affiliation(s)
- Arjan Vissink
- Department of Oral and Maxillofacial Surgery, University Medical Center Groningen, University of Groningen, Grongingen, The Netherlands
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