1101
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Moiseenko V, Song WY, Mell LK, Bhandare N. A comparison of dose-response characteristics of four NTCP models using outcomes of radiation-induced optic neuropathy and retinopathy. Radiat Oncol 2011; 6:61. [PMID: 21645390 PMCID: PMC3127783 DOI: 10.1186/1748-717x-6-61] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 06/06/2011] [Indexed: 12/25/2022] Open
Abstract
Background Biological models are used to relate the outcome of radiation therapy to dose distribution. As use of biological models in treatment planning expands, uncertainties associated with the use of specific models for predicting outcomes should be understood and quantified. In particular, the question to what extent model predictions are data-driven or dependent on the choice of the model has to be explored. Methods Four dose-response models--logistic, log-logistic, Poisson-based and probit--were tested for their ability and consistency in describing dose-response data for radiation-induced optic neuropathy (RION) and retinopathy (RIRP). Dose to the optic nerves was specified as the minimum dose, Dmin, received by any segment of the organ to which the damage was diagnosed by ophthalmologic evaluation. For retinopathy, the dose to the retina was specified as the highest isodose covering at least 1/3 of the retinal surface (D33%) that geometrically covered the observed retinal damage. Data on both complications were modeled separately for patients treated once daily and twice daily. Model parameters D50 and γ and corresponding confidence intervals were obtained using maximum-likelihood method. Results Model parameters were reasonably consistent for RION data for patients treated once daily, D50 ranging from 94.2 to 104.7 Gy and γ from 0.88 to 1.41. Similar consistency was seen for RIRP data which span a broad range of complication incidence, with D50 from 72.2 to 75.0 Gy and γ from 1.51 to 2.16 for patients treated twice daily; 72.2-74.0 Gy and 0.84-1.20 for patients treated once daily. However, large variations were observed for RION in patients treated twice daily, D50 from 96.3 to 125.2 Gy and γ from 0.80 to 1.56. Complication incidence in this dataset in any dose group did not exceed 20%. Conclusions For the considered data sets, the log-logistic model tends to lead to larger D50 and lower γ compared to other models for all datasets. Statements regarding normal tissue radiosensitivity and steepness of dose-response, based on model parameters, should be made with caution as the latter are not only model-dependent but also sensitive to the range of complication incidence exhibited by clinical data.
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Affiliation(s)
- Vitali Moiseenko
- University of Florida Health Sciences Center, Gainesville, FL 32610-0385, USA
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1102
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Lennernäs B, Castellanos E, Nilsson S, Levitt S. Four and five dimensional radiotherapy with reference to prostate cancer--definitions, state of the art and further directions--an overview. Acta Oncol 2011; 50 Suppl 1:104-10. [PMID: 21604949 DOI: 10.3109/0284186x.2010.530003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Radiotherapy (RT) always requires a compromise between tumor control and normal tissue side-effects. Technical innovation in radiation therapy (RT), such as three dimensional RT, is now established. Concerning prostate cancer (PC), it is reasonable to assume that RT of PC will increase in the future. The combination of small margins, a movable target (prostate), few fractions and high doses will probably demand dynamically positioning systems and in real time. This is called four dimensional radiotherapy (4DRT). Moreover, biological factors must be included in new treatments such as hypofractionation schedules. This new era is called five dimensional radiotherapy, 5DRT. In this paper we discuss new concepts in RT in respect to PC.
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Affiliation(s)
- Bo Lennernäs
- Department of Oncology, Sahlgrenska Hospital and Academy, University of Gothenburg, Gothenburg, Sweden.
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1103
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Bortfeld T, Jeraj R. The physical basis and future of radiation therapy. Br J Radiol 2011; 84:485-98. [PMID: 21606068 PMCID: PMC3473639 DOI: 10.1259/bjr/86221320] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 12/23/2010] [Accepted: 01/06/2011] [Indexed: 12/25/2022] Open
Abstract
The remarkable progress in radiation therapy over the last century has been largely due to our ability to more effectively focus and deliver radiation to the tumour target volume. Physics discoveries and technology inventions have been an important driving force behind this progress. However, there is still plenty of room left for future improvements through physics, for example image guidance and four-dimensional motion management and particle therapy, as well as increased efficiency of more compact and cheaper technologies. Bigger challenges lie ahead of physicists in radiation therapy beyond the dose localisation problem, for example in the areas of biological target definition, improved modelling for normal tissues and tumours, advanced multicriteria and robust optimisation, and continuous incorporation of advanced technologies such as molecular imaging. The success of physics in radiation therapy has been based on the continued "fuelling" of the field with new discoveries and inventions from physics research. A key to the success has been the application of the rigorous scientific method. In spite of the importance of physics research for radiation therapy, too few physicists are currently involved in cutting-edge research. The increased emphasis on more "professionalism" in medical physics will tip the situation even more off balance. To prevent this from happening, we argue that medical physics needs more research positions, and more and better academic programmes. Only with more emphasis on medical physics research will the future of radiation therapy and other physics-related medical specialties look as bright as the past, and medical physics will maintain a status as one of the most exciting fields of applied physics.
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Affiliation(s)
- T Bortfeld
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, 30 Fruit St., Boston, MA 02114, USA.
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1104
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Bruzzaniti V, Abate A, Pedrini M, Benassi M, Strigari L. IsoBED: a tool for automatic calculation of biologically equivalent fractionation schedules in radiotherapy using IMRT with a simultaneous integrated boost (SIB) technique. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2011; 30:52. [PMID: 21554675 PMCID: PMC3117739 DOI: 10.1186/1756-9966-30-52] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Accepted: 05/09/2011] [Indexed: 12/22/2022]
Abstract
Background An advantage of the Intensity Modulated Radiotherapy (IMRT) technique is the feasibility to deliver different therapeutic dose levels to PTVs in a single treatment session using the Simultaneous Integrated Boost (SIB) technique. The paper aims to describe an automated tool to calculate the dose to be delivered with the SIB-IMRT technique in different anatomical regions that have the same Biological Equivalent Dose (BED), i.e. IsoBED, compared to the standard fractionation. Methods Based on the Linear Quadratic Model (LQM), we developed software that allows treatment schedules, biologically equivalent to standard fractionations, to be calculated. The main radiobiological parameters from literature are included in a database inside the software, which can be updated according to the clinical experience of each Institute. In particular, the BED to each target volume will be computed based on the alpha/beta ratio, total dose and the dose per fraction (generally 2 Gy for a standard fractionation). Then, after selecting the reference target, i.e. the PTV that controls the fractionation, a new total dose and dose per fraction providing the same isoBED will be calculated for each target volume. Results The IsoBED Software developed allows: 1) the calculation of new IsoBED treatment schedules derived from standard prescriptions and based on LQM, 2) the conversion of the dose-volume histograms (DVHs) for each Target and OAR to a nominal standard dose at 2Gy per fraction in order to be shown together with the DV-constraints from literature, based on the LQM and radiobiological parameters, and 3) the calculation of Tumor Control Probability (TCP) and Normal Tissue Complication Probability (NTCP) curve versus the prescribed dose to the reference target.
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Affiliation(s)
- Vicente Bruzzaniti
- Laboratory of Medical Physics and Expert System, Regina Elena Cancer Institute, Rome, Italy.
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1105
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Boomsma MJ, Bijl HP, Langendijk JA. Radiation-induced hypothyroidism in head and neck cancer patients: a systematic review. Radiother Oncol 2011; 99:1-5. [PMID: 21459468 DOI: 10.1016/j.radonc.2011.03.002] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Revised: 02/20/2011] [Accepted: 03/10/2011] [Indexed: 12/25/2022]
Abstract
PURPOSE To review literature on the relationship between the dose distribution in the thyroid gland and the incidence of radiation-induced hypothyroidism in adults. MATERIAL AND METHODS Articles were identified through a search in MEDLINE, EMBASE and the Cochrane Library. Approximately 2449 articles were screened and selected by inclusion- and exclusion criteria. Eventually, there were five papers that fulfilled the eligibility criteria to be included in this review. RESULTS The sample sizes of the reviewed studies vary from 57 to 390 patients. The incidence of hypothyroidism was much higher (23-53%) than would be expected in a non-irradiated cohort. There was a large heterogeneity between the studies regarding study design, estimation of the dose to the thyroid gland and definition of endpoints. In general, the relationship between thyroid gland volume absorbing 10-70Gy (V10-V70), mean dose (Dmean), minimal dose (Dmin), maximum dose (Dmax) and point doses with hypothyroidism were analysed. An association between dose-volume parameters and hypothyroidism was found in two studies. CONCLUSIONS Hypothyroidism is frequently observed after radiation. Although the results suggest that higher radiation doses to the thyroid gland are associated with hypothyroidism, it was not possible to define a clear threshold radiation dose for the thyroid gland.
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Affiliation(s)
- Marjolein J Boomsma
- Department of Radiation Oncology, University Medical Center Groningen, The Netherlands.
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1106
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Myerson RJ. Normal tissue dose conformality measures to guide radiotherapy fractionation decisions. Med Phys 2011; 38:1799-805. [DOI: 10.1118/1.3560417] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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1107
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New approach for treatment of vertebral metastases using intensity-modulated radiotherapy. Strahlenther Onkol 2011; 187:108-13. [PMID: 21293837 DOI: 10.1007/s00066-010-2187-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Accepted: 11/11/2010] [Indexed: 12/25/2022]
Abstract
PURPOSE To perform aggressive radiotherapy for vertebral metastases. Using very steep dose gradients from intensity-modulated radiotherapy (IMRT), a protocol based on the concept of partial volume dose to the spinal cord was evaluated. PATIENTS AND METHODS 50 patients with vertebral metastases were treated using IMRT. In previously unirradiated cases, where a prescribed dose of 80 Gy (BED10) was delivered, the constraint to the spinal cord should be less than 100 Gy (BED2). For previously irradiated cases, on the other hand, the dose is the same as in the previously unirradiated case; however, constraints for the spinal cord are a cumulative BED2 of less than 150 Gy, BED2 of less than 100 Gy in each instance, and a treatment gap of more than 6 months. There were 6 patients considered for a partial volume dose to the spinal cord. They all received higher BED2, ranging from 51-157 Gy of D1cc. RESULTS Among the 24 patients who survived longer than 1 year, there was 1 case of transient radiation myelitis. There were no other cases of spinal cord sequelae. CONCLUSION Based on the present results, we recommend a BED2 of 100 Gy or less at D1cc as a constraint for the spinal cord in previously unirradiated cases, and a cumulative BED2 of 150 Gy or less at D1cc in previously irradiated cases, when the interval was not shorter than 6 months and the BED2 for each session was 100 Gy or less. The prescribed BED10 of 80 Gy could be safely delivered to the vertebral lesions.
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1108
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Kirkpatrick JP, Marks LB, Mayo CS, Lawrence YR, Bhandare N, Ryu S. Estimating normal tissue toxicity in radiosurgery of the CNS: application and limitations of QUANTEC. JOURNAL OF RADIOSURGERY AND SBRT 2011; 1:95-107. [PMID: 29296303 PMCID: PMC5675466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 05/23/2011] [Indexed: 06/07/2023]
Abstract
Minimizing radiation-induced normal tissue damage in the central nervous system (CNS) is a key objective and primary impetus for stereotactic radiosurgery and radiotherapy. The recently published Quantitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC) study provides updated dose/volume/ outcome data on normal tissue tolerance for sixteen anatomic sites, including the CNS. Most of the data used to develop the relationship between dose, volume and normal tissue toxicity derived from large field, conventionally fractionated regimens, and quantitative dose/volume/outcome data at high doses per fraction to limited volumes is much sparser. Nonetheless, QUANTEC provides some limited recommendations for dose constraints in stereotactic radiosurgery/ radiotherapy of the CNS. This paper critically reviews the findings, recommendations and limitations of QUANTEC as they apply to radiosurgery of the CNS, as well as presenting suggestions to establish and validate clinically meaningful dose/volume/toxicity relationships in this setting.
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Affiliation(s)
- John P. Kirkpatrick
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, USA
| | - Lawrence B. Marks
- Department of Radiation Oncology, University of North Carolina, Chapel Hill, NC, USA
| | - Charles S. Mayo
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota, USA
| | - Yaacov R. Lawrence
- Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Niranjan Bhandare
- Departments of Radiation Oncology and Otolaryngology, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Samuel Ryu
- Department of Radiation Oncology, Henry Ford Hospital, Detroit, MI, USA
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1109
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De Ruysscher D, Faivre-Finn C, Nestle U, Hurkmans CW, Le Péchoux C, Price A, Senan S. European Organisation for Research and Treatment of Cancer Recommendations for Planning and Delivery of High-Dose, High-Precision Radiotherapy for Lung Cancer. J Clin Oncol 2010; 28:5301-10. [DOI: 10.1200/jco.2010.30.3271] [Citation(s) in RCA: 203] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Purpose To derive recommendations for routine practice and clinical trials for techniques used in high-dose, high-precision thoracic radiotherapy for lung cancer. Methods A literature search was performed to identify published articles considered both clinically relevant and practical to use. Recommendations were categorized under the following headings: patient selection, patient positioning and immobilization, tumor motion, computed tomography and [18F]fluorodeoxyglucose–positron emission technology scanning, generating target volumes, radiotherapy treatment planning, treatment delivery, and scoring of response and toxicity. The American College of Chest Physicians grading of recommendations was used. Results Recommendations were identified for each of the recommendation categories. Although most of the recommended techniques have not been evaluated in multicenter clinical trials, their use in high-precision thoracic radiotherapy and stereotactic body radiotherapy (SBRT) appears to be justified on the basis of available evidence. Conclusion Recommendations to facilitate the clinical implementation of high-precision conformal radiotherapy and SBRT for lung tumors were identified from the literature. Some techniques that are considered investigational at present were also highlighted.
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Affiliation(s)
- Dirk De Ruysscher
- From the Maastricht University Medical Center, GROW Research Institute, Maastricht; Free University Medical Center, Amsterdam; and Catharina Hospital, Eindhoven, the Netherlands; the Christie, Manchester; and Edinburgh Cancer Centre, Western General Hospital, Edinburgh, United Kingdom; Freiburg University Medical Center, Freiburg, Germany; and Gustave Roussy Institute, Villejuif, France
| | - Corinne Faivre-Finn
- From the Maastricht University Medical Center, GROW Research Institute, Maastricht; Free University Medical Center, Amsterdam; and Catharina Hospital, Eindhoven, the Netherlands; the Christie, Manchester; and Edinburgh Cancer Centre, Western General Hospital, Edinburgh, United Kingdom; Freiburg University Medical Center, Freiburg, Germany; and Gustave Roussy Institute, Villejuif, France
| | - Ursula Nestle
- From the Maastricht University Medical Center, GROW Research Institute, Maastricht; Free University Medical Center, Amsterdam; and Catharina Hospital, Eindhoven, the Netherlands; the Christie, Manchester; and Edinburgh Cancer Centre, Western General Hospital, Edinburgh, United Kingdom; Freiburg University Medical Center, Freiburg, Germany; and Gustave Roussy Institute, Villejuif, France
| | - Coen W. Hurkmans
- From the Maastricht University Medical Center, GROW Research Institute, Maastricht; Free University Medical Center, Amsterdam; and Catharina Hospital, Eindhoven, the Netherlands; the Christie, Manchester; and Edinburgh Cancer Centre, Western General Hospital, Edinburgh, United Kingdom; Freiburg University Medical Center, Freiburg, Germany; and Gustave Roussy Institute, Villejuif, France
| | - Cécile Le Péchoux
- From the Maastricht University Medical Center, GROW Research Institute, Maastricht; Free University Medical Center, Amsterdam; and Catharina Hospital, Eindhoven, the Netherlands; the Christie, Manchester; and Edinburgh Cancer Centre, Western General Hospital, Edinburgh, United Kingdom; Freiburg University Medical Center, Freiburg, Germany; and Gustave Roussy Institute, Villejuif, France
| | - Allan Price
- From the Maastricht University Medical Center, GROW Research Institute, Maastricht; Free University Medical Center, Amsterdam; and Catharina Hospital, Eindhoven, the Netherlands; the Christie, Manchester; and Edinburgh Cancer Centre, Western General Hospital, Edinburgh, United Kingdom; Freiburg University Medical Center, Freiburg, Germany; and Gustave Roussy Institute, Villejuif, France
| | - Suresh Senan
- From the Maastricht University Medical Center, GROW Research Institute, Maastricht; Free University Medical Center, Amsterdam; and Catharina Hospital, Eindhoven, the Netherlands; the Christie, Manchester; and Edinburgh Cancer Centre, Western General Hospital, Edinburgh, United Kingdom; Freiburg University Medical Center, Freiburg, Germany; and Gustave Roussy Institute, Villejuif, France
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1110
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Yoo DS, Wong TZ, Brizel DM. The Role of Adaptive and Functional Imaging Modalities in Radiation Therapy: Approach and Application from a Radiation Oncology Perspective. Semin Ultrasound CT MR 2010; 31:444-61. [DOI: 10.1053/j.sult.2010.10.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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1111
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Forquer JA. Thymic neoplasms. Curr Probl Cancer 2010; 34:328-66. [PMID: 21112444 DOI: 10.1016/j.currproblcancer.2010.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Jeffrey A Forquer
- Department of Radiation Oncology, The University of Toledo Medical Center, Toledo, Ohio, USA
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1112
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de Crevoisier R, Fiorino C, Dubray B. Radiothérapie prostatique : prédiction de la toxicité tardive à partir des données dosimétriques. Cancer Radiother 2010; 14:460-8. [DOI: 10.1016/j.canrad.2010.07.225] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Accepted: 07/12/2010] [Indexed: 12/25/2022]
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1113
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Abstract
With the introduction of new biologically based imaging possibilities, a higher degree of individualisation and adaptation of radiotherapy will be possible. Better knowledge of the biology of the target and its sub-volumes will enable dose prescriptions tailored to the individual patients, tissues and sub-volumes. Repeated imaging during the course of treatment will in addition enable adaptation of the treatment to cope with anatomical, as well as biological changes of the patient and of the target tissues. To translate these bright future perspectives into significant improvements in clinical outcome, advanced tools to tailor the physical dose distributions are needed. The most conformal radiotherapy technique known to mankind and clinically available today is proton therapy; in particular Intensity Modulated Proton Therapy (IMPT) with active spot scanning can not only tailor the dose to the desired target, but also effectively avoid sensitive structures in the proximity of the target to a degree far better than other conformal techniques such as Intensity Modulated Radiotherapy with photons (IMRT). The development of IMPT is now mature enough for clinical introduction on a broad scale. Proton therapy is still more expensive than conventional radiotherapy, but with the present rapid increase in the number of proton facilities worldwide and new initiatives to improve efficiency, the difference in affordability will continue to decrease and in comparison with the benefits, soon diminish even further. Contrary to what is sometimes claimed, the demands for better physical dose distributions and better avoidance of non-target tissue, has never been higher. Prolonged expected survival in many groups of patients emphasises the need to reduce late toxicities. The success of concomitant systemic therapies, with their tendency to cause higher morbidity stresses even further the increased need for subtle dose-sculpting methodologies and tools. There is no contradiction between striving for better physical dose distributions and a more biologically based approach. On the contrary, physical dose distributions are the tools to which achieve a treatment that can meet the biological demands.
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1114
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Roelofs E, Persoon L, Qamhiyeh S, Verhaegen F, De Ruysscher D, Scholz M, Iancu G, Engelsman M, Rasch C, Zijp L, Meerleer GD, Coghe M, Langendijk J, Schilstra C, Pijls-Johannesma M, Lambin P. Design of and technical challenges involved in a framework for multicentric radiotherapy treatment planning studies. Radiother Oncol 2010; 97:567-71. [PMID: 20864198 DOI: 10.1016/j.radonc.2010.08.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 04/06/2010] [Accepted: 08/12/2010] [Indexed: 12/25/2022]
Abstract
This report introduces a framework for comparing radiotherapy treatment planning in multicentric in silico clinical trials. Quality assurance, data incompatibility, transfer and storage issues, and uniform analysis of results are discussed. The solutions that are given provide a useful guide for the set-up of future multicentric planning studies or public repositories of high quality data.
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Affiliation(s)
- Erik Roelofs
- Department of Radiation Oncology (MAASTRO), Maastricht University Medical Centre, The Netherlands
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1115
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Facteurs de radiosensibilité tardive des tissus sains. Cancer Radiother 2010; 14:250-4. [DOI: 10.1016/j.canrad.2010.04.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Accepted: 04/08/2010] [Indexed: 12/25/2022]
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