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Sample records for modern radiotherapy techniques

  1. Second cancers in children treated with modern radiotherapy techniques

    International Nuclear Information System (INIS)

    Schneider, Uwe; Lomax, Antony; Timmermann, Beate

    2008-01-01

    Background and Purpose: The scattered radiation from the treatment volume might be more significant for children than for adults and, as a consequence, modern radiotherapy treatment techniques such as IMRT and passive proton therapy could potentially increase the number of secondary cancers. In this report, secondary cancer risk resulting from new treatment technologies was estimated for an adult prostate patient and a child. Material and methods: The organ equivalent dose (OED) concept with a linear-exponential, a plateau and a linear dose-response curve was applied to dose distributions of an adult prostate patient and a child with a rhabdomyosarcoma of the prostate. Conformal radiotherapy, IMRT with 6 MV photons and proton therapy were planned. OED (cancer risk) was estimated for the whole body, the rectum and the bladder. In addition, relative cumulative risk was calculated. Results: Secondary cancer risk in the adult is not more than 15% it increased when IMRT or passive proton therapy was compared to conventional treatment planning. In the child, risk remains practically constant or was even reduced for proton therapy. The cumulative risk in the child relative to that in the adult can be as large as 10-15. Conclusions: By a comparison between an adult patient and a child treated for a disease of the prostate, it was shown that modern radiotherapy techniques such as IMRT and proton therapy (active and passive) do not increase the risk for secondary cancers

  2. Ewing sarcoma in adults treated with modern radiotherapy techniques

    International Nuclear Information System (INIS)

    Casey, Dana L.; Meyers, Paul A.; Alektiar, Kaled M.; Magnan, Heather; Healey, John H.; Boland, Patrick J.; Wolden, Suzanne L.

    2014-01-01

    Background and purpose: To evaluate local control and survival outcomes in adults with Ewing sarcoma (ES) treated with radiotherapy (RT). Material and methods: Retrospective review of all 109 patients age ⩾18 treated for ES with RT to the primary site at Memorial Sloan Kettering Cancer Center between 1990 and 2011. RT was used as the definitive local control modality in 44% of patients, preoperatively for 6%, and postoperatively for 50%. Results: Median age at diagnosis was 27 years (range, 18–67). The 5-year local failure (LF) was 18%. Differences in LF were not identified when evaluated by modality of local control (RT versus combined surgery and RT), RT dose, fractionation, and RT technique. However, margin status at time of resection significantly predicted LF. The 5-year event-free survival and overall survival rates were 44% and 66% for patients with localized disease, compared with 16% and 26% for metastatic disease (p = 0.0005 and 0.0002). Tumor size, histopathologic response to chemotherapy, and treatment on or according to a protocol were also significantly associated with survival. Conclusions: This series of adults treated with modern chemotherapy and RT had prognostic factors and outcomes similar to adolescents with ES. All adults with ES should be treated with an aggressive, multidisciplinary approach

  3. Cost-effectiveness of modern radiotherapy techniques in locally advanced pancreatic cancer.

    Science.gov (United States)

    Murphy, James D; Chang, Daniel T; Abelson, Jon; Daly, Megan E; Yeung, Heidi N; Nelson, Lorene M; Koong, Albert C

    2012-02-15

    Radiotherapy may improve the outcome of patients with pancreatic cancer but at an increased cost. In this study, the authors evaluated the cost-effectiveness of modern radiotherapy techniques in the treatment of locally advanced pancreatic cancer. A Markov decision-analytic model was constructed to compare the cost-effectiveness of 4 treatment regimens: gemcitabine alone, gemcitabine plus conventional radiotherapy, gemcitabine plus intensity-modulated radiotherapy (IMRT); and gemcitabine with stereotactic body radiotherapy (SBRT). Patients transitioned between the following 5 health states: stable disease, local progression, distant failure, local and distant failure, and death. Health utility tolls were assessed for radiotherapy and chemotherapy treatments and for radiation toxicity. SBRT increased life expectancy by 0.20 quality-adjusted life years (QALY) at an increased cost of $13,700 compared with gemcitabine alone (incremental cost-effectiveness ratio [ICER] = $69,500 per QALY). SBRT was more effective and less costly than conventional radiotherapy and IMRT. An analysis that excluded SBRT demonstrated that conventional radiotherapy had an ICER of $126,800 per QALY compared with gemcitabine alone, and IMRT had an ICER of $1,584,100 per QALY compared with conventional radiotherapy. A probabilistic sensitivity analysis demonstrated that the probability of cost-effectiveness at a willingness to pay of $50,000 per QALY was 78% for gemcitabine alone, 21% for SBRT, 1.4% for conventional radiotherapy, and 0.01% for IMRT. At a willingness to pay of $200,000 per QALY, the probability of cost-effectiveness was 73% for SBRT, 20% for conventional radiotherapy, 7% for gemcitabine alone, and 0.7% for IMRT. The current results indicated that IMRT in locally advanced pancreatic cancer exceeds what society considers cost-effective. In contrast, combining gemcitabine with SBRT increased clinical effectiveness beyond that of gemcitabine alone at a cost potentially acceptable by

  4. Vertical mammaplasty associated with accelerated partial breast radiotherapy: how oncoplastic surgery techniques associated with modern techniques of radiotherapy can improve the aesthetic outcome in selected patients

    Energy Technology Data Exchange (ETDEWEB)

    Couto, Henrique Lima, E-mail: enriquecouto@hotmail.com [Santa Fe Women' s and Maternity Hospital, Belo Horizonte, MG (Brazil); Amorim, Washington Cancado; Guimaraes, Rodrigo [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Hospital Geral; Ramires, Leandro Cruz; Castilho, Marcus Simoes [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Fac. de Medicina; Dominguez, Lorena Lima Coto [Universidade Estacio de Sa (UNESA), Rio de Janeiro, EJ (Brazil)

    2014-07-15

    Breast cancer is the second most common type of cancer in the world, being the most common among women, responsible for 22% of new cases each year. It's surgical and radiation treatment evolved from radical procedures (Halsted radical mastectomy and total external breast radiotherapy) to less radical and more conservative procedures. With the use of modern oncoplastic surgery techniques and accelerated partial breast radiotherapy, selected patients can benefit with better aesthetic results, fewer side effects, and more comfortable and brief treatments. (author)

  5. Vertical mammaplasty associated with accelerated partial breast radiotherapy: how oncoplastic surgery techniques associated with modern techniques of radiotherapy can improve the aesthetic outcome in selected patients

    International Nuclear Information System (INIS)

    Couto, Henrique Lima; Amorim, Washington Cancado; Guimaraes, Rodrigo

    2014-01-01

    Breast cancer is the second most common type of cancer in the world, being the most common among women, responsible for 22% of new cases each year. It's surgical and radiation treatment evolved from radical procedures (Halsted radical mastectomy and total external breast radiotherapy) to less radical and more conservative procedures. With the use of modern oncoplastic surgery techniques and accelerated partial breast radiotherapy, selected patients can benefit with better aesthetic results, fewer side effects, and more comfortable and brief treatments. (author)

  6. Radiation-Induced Cancers From Modern Radiotherapy Techniques: Intensity-Modulated Radiotherapy Versus Proton Therapy

    International Nuclear Information System (INIS)

    Yoon, Myonggeun; Ahn, Sung Hwan; Kim, Jinsung; Shin, Dong Ho; Park, Sung Yong; Lee, Se Byeong; Shin, Kyung Hwan; Cho, Kwan Ho

    2010-01-01

    Purpose: To assess and compare secondary cancer risk resulting from intensity-modulated radiotherapy (IMRT) and proton therapy in patients with prostate and head-and-neck cancer. Methods and Materials: Intensity-modulated radiotherapy and proton therapy in the scattering mode were planned for 5 prostate caner patients and 5 head-and-neck cancer patients. The secondary doses during irradiation were measured using ion chamber and CR-39 detectors for IMRT and proton therapy, respectively. Organ-specific radiation-induced cancer risk was estimated by applying organ equivalent dose to dose distributions. Results: The average secondary doses of proton therapy for prostate cancer patients, measured 20-60cm from the isocenter, ranged from 0.4 mSv/Gy to 0.1 mSv/Gy. The average secondary doses of IMRT for prostate patients, however, ranged between 3 mSv/Gy and 1 mSv/Gy, approximately one order of magnitude higher than for proton therapy. Although the average secondary doses of IMRT were higher than those of proton therapy for head-and-neck cancers, these differences were not significant. Organ equivalent dose calculations showed that, for prostate cancer patients, the risk of secondary cancers in out-of-field organs, such as the stomach, lungs, and thyroid, was at least 5 times higher for IMRT than for proton therapy, whereas the difference was lower for head-and-neck cancer patients. Conclusions: Comparisons of organ-specific organ equivalent dose showed that the estimated secondary cancer risk using scattering mode in proton therapy is either significantly lower than the cases in IMRT treatment or, at least, does not exceed the risk induced by conventional IMRT treatment.

  7. Accuracy required and achievable in radiotherapy dosimetry: have modern technology and techniques changed our views?

    Science.gov (United States)

    Thwaites, David

    2013-06-01

    In this review of the accuracy required and achievable in radiotherapy dosimetry, older approaches and evidence-based estimates for 3DCRT have been reprised, summarising and drawing together the author's earlier evaluations where still relevant. Available evidence for IMRT uncertainties has been reviewed, selecting information from tolerances, QA, verification measurements, in vivo dosimetry and dose delivery audits, to consider whether achievable uncertainties increase or decrease for current advanced treatments and practice. Overall there is some evidence that they tend to increase, but that similar levels should be achievable. Thus it is concluded that those earlier estimates of achievable dosimetric accuracy are still applicable, despite the changes and advances in technology and techniques. The one exception is where there is significant lung involvement, where it is likely that uncertainties have now improved due to widespread use of more accurate heterogeneity models. Geometric uncertainties have improved with the wide availability of IGRT.

  8. Radiation dose verification using real tissue phantom in modern radiotherapy techniques

    International Nuclear Information System (INIS)

    Gurjar, Om Prakash; Mishra, S.P.; Bhandari, Virendra; Pathak, Pankaj; Patel, Prapti; Shrivastav, Garima

    2014-01-01

    In vitro dosimetric verification prior to patient treatment has a key role in accurate and precision radiotherapy treatment delivery. Most of commercially available dosimetric phantoms have almost homogeneous density throughout their volume, while real interior of patient body has variable and varying densities inside. In this study an attempt has been made to verify the physical dosimetry in actual human body scenario by using goat head as 'head phantom' and goat meat as 'tissue phantom'. The mean percentage variation between planned and measured doses was found to be 2.48 (standard deviation (SD): 0.74), 2.36 (SD: 0.77), 3.62 (SD: 1.05), and 3.31 (SD: 0.78) for three-dimensional conformal radiotherapy (3DCRT) (head phantom), intensity modulated radiotherapy (IMRT; head phantom), 3DCRT (tissue phantom), and IMRT (tissue phantom), respectively. Although percentage variations in case of head phantom were within tolerance limit (< ± 3%), but still it is higher than the results obtained by using commercially available phantoms. And the percentage variations in most of cases of tissue phantom were out of tolerance limit. On the basis of these preliminary results it is logical and rational to develop radiation dosimetry methods based on real human body and also to develop an artificial phantom which should truly represent the interior of human body. (author)

  9. Radiation dose verification using real tissue phantom in modern radiotherapy techniques

    Directory of Open Access Journals (Sweden)

    Om Prakash Gurjar

    2014-01-01

    Full Text Available In vitro dosimetric verification prior to patient treatment has a key role in accurate and precision radiotherapy treatment delivery. Most of commercially available dosimetric phantoms have almost homogeneous density throughout their volume, while real interior of patient body has variable and varying densities inside. In this study an attempt has been made to verify the physical dosimetry in actual human body scenario by using goat head as "head phantom" and goat meat as "tissue phantom". The mean percentage variation between planned and measured doses was found to be 2.48 (standard deviation (SD: 0.74, 2.36 (SD: 0.77, 3.62 (SD: 1.05, and 3.31 (SD: 0.78 for three-dimensional conformal radiotherapy (3DCRT (head phantom, intensity modulated radiotherapy (IMRT; head phantom, 3DCRT (tissue phantom, and IMRT (tissue phantom, respectively. Although percentage variations in case of head phantom were within tolerance limit (< ± 3%, but still it is higher than the results obtained by using commercially available phantoms. And the percentage variations in most of cases of tissue phantom were out of tolerance limit. On the basis of these preliminary results it is logical and rational to develop radiation dosimetry methods based on real human body and also to develop an artificial phantom which should truly represent the interior of human body.

  10. Left-sided breast cancer and risks of secondary lung cancer and ischemic heart disease. Effects of modern radiotherapy techniques

    Energy Technology Data Exchange (ETDEWEB)

    Corradini, Stefanie; Ballhausen, Hendrik; Weingandt, Helmut; Freislederer, Philipp; Schoenecker, Stephan; Niyazi, Maximilian; Belka, Claus [University Hospital, LMU Munich, Department of Radiation Oncology, Munich (Germany); Simonetto, Cristoforo; Eidemueller, Markus [Helmholtz Zentrum Muenchen, Institute of Radiation Protection, Neuherberg (Germany); Ganswindt, Ute [University Hospital, LMU Munich, Department of Radiation Oncology, Munich (Germany); Medical University, Department of Radiation Oncology, Innsbruck (Austria)

    2018-03-15

    Modern breast cancer radiotherapy techniques, such as respiratory-gated radiotherapy in deep-inspiration breath-hold (DIBH) or volumetric-modulated arc radiotherapy (VMAT) have been shown to reduce the high dose exposure of the heart in left-sided breast cancer. The aim of the present study was to comparatively estimate the excess relative and absolute risks of radiation-induced secondary lung cancer and ischemic heart disease for different modern radiotherapy techniques. Four different treatment plans were generated for ten computed tomography data sets of patients with left-sided breast cancer, using either three-dimensional conformal radiotherapy (3D-CRT) or VMAT, in free-breathing (FB) or DIBH. Dose-volume histograms were used for organ equivalent dose (OED) calculations using linear, linear-exponential, and plateau models for the lung. A linear model was applied to estimate the long-term risk of ischemic heart disease as motivated by epidemiologic data. Excess relative risk (ERR) and 10-year excess absolute risk (EAR) for radiation-induced secondary lung cancer and ischemic heart disease were estimated for different representative baseline risks. The DIBH maneuver resulted in a significant reduction of the ERR and estimated 10-year excess absolute risk for major coronary events compared to FB in 3D-CRT plans (p = 0.04). In VMAT plans, the mean predicted risk reduction through DIBH was less pronounced and not statistically significant (p = 0.44). The risk of radiation-induced secondary lung cancer was mainly influenced by the radiotherapy technique, with no beneficial effect through DIBH. VMAT plans correlated with an increase in 10-year EAR for radiation-induced lung cancer as compared to 3D-CRT plans (DIBH p = 0.007; FB p = 0.005, respectively). However, the EARs were affected more strongly by nonradiation-associated risk factors, such as smoking, as compared to the choice of treatment technique. The results indicate that 3D-CRT plans in DIBH pose the lowest

  11. Treatment of nasal cavity and paranasal sinus cancer with modern radiotherapy techniques in the postoperative setting-the MSKCC experience

    International Nuclear Information System (INIS)

    Hoppe, Bradford S.; Stegman, Lauren D.; Zelefsky, Michael J.; Rosenzweig, Kenneth E.; Wolden, Suzanne L.; Patel, Snehal G.; Shah, Jatin P.; Kraus, Dennis H.; Lee, Nancy Y.

    2007-01-01

    Purpose: To perform a retrospective analysis of patients with paranasal sinus (PNS) cancer treated with postoperative radiotherapy (RT) at Memorial Sloan-Kettering Cancer Center. Methods and Materials: Between January 1987 and July 2005, 85 patients with PNS and nasal cavity cancer underwent postoperative RT. Most patients had squamous cell carcinoma (49%; n = 42), T4 tumors (52%; n = 36), and the maxillary sinus (53%; n = 45) as the primary disease site. The median radiation dose was 63 Gy. Of the 85 patients, 76 underwent CT simulation and 53 were treated with either three-dimensional conformal RT (27%; n = 23) or intensity-modulated RT (35%; n = 30). Acute and late toxicities were scored according to the Radiation Therapy Oncology Group radiation morbidity scoring criteria. Results: With a median follow-up for surviving patients of 60 months, the 5-year estimates of local progression-free, regional progression-free, distant metastasis-free, disease-free, and overall survival rates were 62%, 87%, 82%, 55%, and 67%, respectively. On multivariate analysis, squamous cell histology and cribriform plate involvement predicted for an increased likelihood of local recurrence, and squamous cell histologic features predicted for worse overall survival. None of the patients who underwent CT simulation and were treated with modern techniques developed a Grade 3-4 late complication of the eye. Conclusion: Complete surgical resection followed by adjuvant RT is an effective and safe approach in the treatment of PNS cancer. Emerging tools, such as three-dimensional conformal treatment and, in particular, intensity-modulated RT for PNS tumors, may minimize the occurrence of late complications associated with conventional RT techniques. Local recurrence remains a significant problem

  12. Radiotherapy and Brachytherapy : Proceedings of the NATO Advanced Study Institute on Physics of Modern Radiotherapy & Brachytherapy

    CERN Document Server

    Lemoigne, Yves

    2009-01-01

    This volume collects a series of lectures presented at the tenth ESI School held at Archamps (FR) in November 2007 and dedicated to radiotherapy and brachytherapy. The lectures focus on the multiple facets of radiotherapy in general, including external radiotherapy (often called teletherapy) as well as internal radiotherapy (called brachytherapy). Radiotherapy strategy and dose management as well as the decisive role of digital imaging in the associated clinical practice are developed in several articles. Grouped under the discipline of Conformal Radiotherapy (CRT), numerous modern techniques, from Multi-Leaf Collimators (MLC) to Intensity Modulated RadioTherapy (IMRT), are explained in detail. The importance of treatment planning based upon patient data from digital imaging (Computed Tomography) is also underlined. Finally, despite the quasi- totality of patients being presently treated with gamma and X-rays, novel powerful tools are emerging using proton and light ions (like carbon ions) beams, bound to bec...

  13. Modern recording techniques

    CERN Document Server

    Huber, David Miles

    2013-01-01

    As the most popular and authoritative guide to recording Modern Recording Techniques provides everything you need to master the tools and day to day practice of music recording and production. From room acoustics and running a session to mic placement and designing a studio Modern Recording Techniques will give you a really good grounding in the theory and industry practice. Expanded to include the latest digital audio technology the 7th edition now includes sections on podcasting, new surround sound formats and HD and audio.If you are just starting out or looking for a step up

  14. Radiotherapy in prostate cancer. Innovative techniques and current controversies

    International Nuclear Information System (INIS)

    Geinitz, Hans

    2015-01-01

    Examines in detail the role of innovative radiation techniques in the management of prostate cancer, including IMRT, IGRT, BART, and modern brachytherapy. Explores a range of current controversies in patient treatment. Intended for both radiation oncologists and urologists. Radiation treatment is rapidly evolving owing to the coordinated research of physicists, engineers, computer and imaging specialists, and physicians. Today, the arsenal of ''high-precision'' or ''targeted'' radiotherapy includes multimodal imaging, in vivo dosimetry, Monte Carlo techniques for dose planning, patient immobilization techniques, intensity-modulated radiotherapy (IMRT), image-guided radiotherapy (IGRT), biologically adapted radiotherapy (BART), quality assurance methods, novel methods of brachytherapy, and, at the far end of the scale, particle beam radiotherapy using protons and carbon ions. These approaches are like pieces of a puzzle that need to be put together to provide the prostate cancer patient with high-level optimized radiation treatment. This book examines in detail the role of the above-mentioned innovative radiation techniques in the management of prostate cancer. In addition, a variety of current controversies regarding treatment are carefully explored, including whether prophylactic treatment of the pelvic lymphatics is essential, the magnitude of the effect of dose escalation, whether a benefit accrues from hypofractionation, and what evidence exists for the superiority of protons or heavy ions. Radiotherapy in Prostate Cancer: Innovative Techniques and Current Controversies is intended for both radiation oncologists and urologists with an interest in the up-to-date capabilities of modern radiation oncology for the treatment of prostate cancer.

  15. Radiotherapy in prostate cancer. Innovative techniques and current controversies

    Energy Technology Data Exchange (ETDEWEB)

    Geinitz, Hans [Krankenhaus der Barmherzigen Schwestern, Linz (Austria). Dept. of Radiation Oncology; Linz Univ. (Austria). Medical Faculty; Roach, Mack III [California Univ., San Francisco, CA (United States). Dept. of Radiation Oncology; Van As, Nicholas (ed.) [The Institute of Cancer Research, Sutton Surrey (United Kingdom)

    2015-04-01

    Examines in detail the role of innovative radiation techniques in the management of prostate cancer, including IMRT, IGRT, BART, and modern brachytherapy. Explores a range of current controversies in patient treatment. Intended for both radiation oncologists and urologists. Radiation treatment is rapidly evolving owing to the coordinated research of physicists, engineers, computer and imaging specialists, and physicians. Today, the arsenal of ''high-precision'' or ''targeted'' radiotherapy includes multimodal imaging, in vivo dosimetry, Monte Carlo techniques for dose planning, patient immobilization techniques, intensity-modulated radiotherapy (IMRT), image-guided radiotherapy (IGRT), biologically adapted radiotherapy (BART), quality assurance methods, novel methods of brachytherapy, and, at the far end of the scale, particle beam radiotherapy using protons and carbon ions. These approaches are like pieces of a puzzle that need to be put together to provide the prostate cancer patient with high-level optimized radiation treatment. This book examines in detail the role of the above-mentioned innovative radiation techniques in the management of prostate cancer. In addition, a variety of current controversies regarding treatment are carefully explored, including whether prophylactic treatment of the pelvic lymphatics is essential, the magnitude of the effect of dose escalation, whether a benefit accrues from hypofractionation, and what evidence exists for the superiority of protons or heavy ions. Radiotherapy in Prostate Cancer: Innovative Techniques and Current Controversies is intended for both radiation oncologists and urologists with an interest in the up-to-date capabilities of modern radiation oncology for the treatment of prostate cancer.

  16. Modern control techniques for accelerators

    International Nuclear Information System (INIS)

    Goodwin, R.W.; Shea, M.F.

    1984-01-01

    Beginning in the mid to late sixties, most new accelerators were designed to include computer based control systems. Although each installation differed in detail, the technology of the sixties and early to mid seventies dictated an architecture that was essentially the same for the control systems of that era. A mini-computer was connected to the hardware and to a console. Two developments have changed the architecture of modern systems: the microprocessor and local area networks. This paper discusses these two developments and demonstrates their impact on control system design and implementation by way of describing a possible architecture for any size of accelerator. Both hardware and software aspects are included

  17. Therapeutic Results of Radiotherapy in Rectal Carcinoma -Comparison of Sandwich Technique Radiotherapy with Postoperative Radiotherapy

    International Nuclear Information System (INIS)

    Huh, Gil Cha; Suh, Hyun Suk; Lee, Hyuk Sang; Kim, Re Hwe; Kim, Chul Soo; Kim, Hong Yong; Kim, Sung Rok

    1996-01-01

    Purpose : To evaluate the potential advantage for 'sandwich' technique radiotherapy compared to postoperative radiotherapy in respectable rectal cancer. Between January 1989 and May 1994, 60 patients with respectable rectal cancer were treated at Inje University Seoul and Sanggye Paik Hospital.Fifty one patients were available for analysis : 20 patients were treated with sandwich technique radiotherapy and 31 patients were treated with postoperative radiotherapy. In sandwich technique radiotherapy(RT), patients were treated with preoperative RT 1500 cGy/5fx followed by immediate curative resection. Patients staged as Astler-Coller B2, C were considered for postoperative RT with 2500-4500 cGy. In postoperative RT, total radiation dose of 4500-6120 cGy, 180 cGy daily at 4-6 weeks was delivered. Patients were followed for median period of 25 months. Results : The overall 5-year survival rates for sandwich technique RT group and postoperative RT group were 60% and 71%, respectively(p>0.05). The 5-year disease free survival rates for each group were 63%. There was no difference in local failure rate between two groups(11% versus 7%). Incidence of distant metastasis was 11%(2/20) in the sandwich technique RT group and 20%(6/31) in the postoperative RT group(p>0.05). The frequencies of acute and chronic complications were comparable in both groups. Conclusion : The sandwich technique radiotherapy group shows local recurrence and survival similar to those of postoperative RT alone group but reduced distant metastasis compared to postoperative RT group. But long term follow-up and large number of patients is needed to make an any firm conclusion regarding the value of this sandwich technique RT

  18. Modern indications for post-mastectomy radiotherapy application

    International Nuclear Information System (INIS)

    Parvanova, V.

    2002-01-01

    Before the effective adjuvant chemotherapy, post-mastectomy chemotherapy was usually used in breast cancer patients. The interest in this approach was revived after a number of studies were successful in identifying patient subgroups with 20 and 40 percent of locoregional relapses following mastectomy and chemotherapy. These subgroups including women presenting 4 and more positive lymph odes or an advanced primary tumor (measuring 5 cm or more, or a neoplasm invading skin or contiguous musculature) are taken to be the most likely to benefit from a course od post-mastectomy radiotherapy. Recent randomized trials demonstrate adequate tumor control and heightened overall survival rates when mastectomy is supplemented by radiotherapy. A currently performed meta-analysis of over 22000 women comparing groups with and without adjuvant radiotherapy point to an improvement in locoregional tumor control rates from 70 to 90 percent. The result of a 20-year follow-up study document a significant improvement of overall and disease-specific survivalship. These are findings lending support to the concept that improving locoregional tumor control rates in breast cancer may account for an increase of overall survivorship. Regardless of a rather short follow-up of women undergoing updated radiotherapy techniques, the preliminary results do not show increased incidence of vascular death, but pos-mastectomy radiotherapy continues to be associated with an elevated hand edema risk. For the time being, the role of post-mastectomy radiotherapy in women presenting 1 to 3 positive axillary lymph nodes remains not well enough clarified, and needs further evaluation in randomized clinical trials. (authors)

  19. Modern control techniques for accelerators

    International Nuclear Information System (INIS)

    Goodwin, R.W.; Shea, M.F.

    1984-05-01

    Beginning in the mid to late sixties, most new accelerators were designed to include computer based control systems. Although each installation differed in detail, the technology of the sixties and early to mid seventies dictated an architecture that was essentially the same for the control systems of that era. A mini-computer was connected to the hardware and to a console. Two developments have changed the architecture of modern systems: (a) the microprocessor and (b) local area networks. This paper discusses these two developments and demonstrates their impact on control system design and implementation by way of describing a possible architecture for any size of accelerator. Both hardware and software aspects are included

  20. Modern techniques of surface science

    CERN Document Server

    Woodruff, D Phil

    2016-01-01

    This fully revised, updated and reorganised third edition provides a thorough introduction to the characterisation techniques used in surface science and nanoscience today. Each chapter brings together and compares the different techniques used to address a particular research question, including how to determine the surface composition, surface structure, surface electronic structure, surface microstructure at different length scales (down to sub-molecular), and the molecular character of adsorbates and their adsorption or reaction properties. Readers will easily understand the relative strengths and limitations of the techniques available to them and, ultimately, will be able to select the most suitable techniques for their own particular research purposes. This is an essential resource for researchers and practitioners performing materials analysis, and for senior undergraduate students looking to gain a clear understanding of the underlying principles and applications of the different characterisation tec...

  1. Soil analysis. Modern instrumental technique

    International Nuclear Information System (INIS)

    Smith, K.A.

    1993-01-01

    This book covers traditional methods of analysis and specialist monographs on individual instrumental techniques, which are usually not written with soil or plant analysis specifically in mind. The principles of the techniques are combined with discussions of sample preparation and matrix problems, and critical reviews of applications in soil science and related disciplines. Individual chapters are processed separately for inclusion in the appropriate data bases

  2. Modern Surveying Techniques In National Infrastructural ...

    African Journals Online (AJOL)

    Journal of Research in National Development ... Modern Surveying Techniques In National Infrastructural Development: Case Study Of Roads ... Ways that Remote Sensing help to make highway construction easier were discussed.

  3. Principles of modern radar advanced techniques

    CERN Document Server

    Melvin, William

    2012-01-01

    Principles of Modern Radar: Advanced Techniques is a professional reference for practicing engineers that provides a stepping stone to advanced practice with in-depth discussions of the most commonly used advanced techniques for radar design. It will also serve advanced radar academic and training courses with a complete set of problems for students as well as solutions for instructors.

  4. Modern techniques of structural neutron diffraction

    International Nuclear Information System (INIS)

    Aksenov, V.L.; )

    1997-01-01

    Modern techniques of neutron diffraction for structural investigations are analyzed. The time-of-flight method and the reverse time-of-flight method are considered briefly. Characteristics of two-crystal and time-of-flight neutron diffractometers are compared. It is pointed that in the future, the great importance will be possessed the development of high-resolution Fourier neutron diffractometers [ru

  5. Long-term follow-up after modern radical prostate cancer radiotherapy

    DEFF Research Database (Denmark)

    Sander, Lotte

    that clinical target volumes are up to 30% smaller on MRI delineation compared to computer tomography delineation. The overall aim of the thesis was to explore the use of MRI target planning and a Nicle-Titanium prostate stent as fiducial marker for both MR-CT co-registration and image guided radiotherapy....... radiotherapy is a well established treatment modality for prostate cancer. Accuracy and precision are key words with regard to optimal survival and minimal toxicity in modern radiotherapy and are fundamentals in modern radiotherapy. Modern imaging has improved the ability to define radiotherapy target volumes......A significant increase in the prostate cancer incidence has made prostate cancer a major health problem in recent years. Because of the often but unfortunately not always indolent nature of the disease, over-diagnosis and over-treatment are relevant clinical and ethic dilemmas. External beam...

  6. Identification of Microorganisms by Modern Analytical Techniques.

    Science.gov (United States)

    Buszewski, Bogusław; Rogowska, Agnieszka; Pomastowski, Paweł; Złoch, Michał; Railean-Plugaru, Viorica

    2017-11-01

    Rapid detection and identification of microorganisms is a challenging and important aspect in a wide range of fields, from medical to industrial, affecting human lives. Unfortunately, classical methods of microorganism identification are based on time-consuming and labor-intensive approaches. Screening techniques require the rapid and cheap grouping of bacterial isolates; however, modern bioanalytics demand comprehensive bacterial studies at a molecular level. Modern approaches for the rapid identification of bacteria use molecular techniques, such as 16S ribosomal RNA gene sequencing based on polymerase chain reaction or electromigration, especially capillary zone electrophoresis and capillary isoelectric focusing. However, there are still several challenges with the analysis of microbial complexes using electromigration technology, such as uncontrolled aggregation and/or adhesion to the capillary surface. Thus, an approach using capillary electrophoresis of microbial aggregates with UV and matrix-assisted laser desorption ionization time-of-flight MS detection is presented.

  7. Timber Elements: Traditional and Modern Strengthening Techniques

    Directory of Open Access Journals (Sweden)

    Raluca Hohan

    2010-01-01

    Full Text Available The main idea of this paper is to analyse the means for the rehabilitation of our cultural heritage timber structures. Several methods together with their application techniques are described, and also, the reasons for what these strengthening operations become imminent at a point. First of all, the necessity of the timber structural elements strengthening is explained through a short presentation of the factors which are degrading the material. Then, certain precautions and strengthening procedures are presented, all involving the usage of traditional materials like wood, metal, or concrete, and of modern materials like fiber reinforced polymeric composite.

  8. Respiratory gated radiotherapy: current techniques and potential benefits

    International Nuclear Information System (INIS)

    Giraud, P.; Campana, F.; Rosenwald, J.C.; Cosset, J.M.; Reboul, F.; Garcia, R.; Clippe, S.; Carrie, C.; Dubray, B.

    2003-01-01

    Respiration-gated radiotherapy offers a significant potential for improvement in the irradiation of tumor sites affected by respiratory motion such as lung, breast and liver tumors. An increased conformality of irradiation fields leading to decreased complications rates of organs at risk (lung, heart...) is expected. Respiratory gating is in line with the need for improved precision required by radiotherapy techniques such as 3D conformal radiotherapy or intensity modulated radiotherapy. Reduction of respiratory motion can be achieved by using either breath hold techniques or respiration synchronized gating techniques. Breath-hold techniques can be achieved with active, in which airflow of the patient is temporarily blocked by a valve, or passive techniques, in which the patient voluntarily breath-hold. Synchronized gating techniques use external devices to predict the phase of the respiration cycle while the patient breaths freely. These techniques presently investigated in several medical centers worldwide. Although promising, the first results obtained in lung and liver cancer patients require confirmation. Physical, technical and physiological questions still remain to be answered. This paper describes the most frequently used gated techniques and the main published clinical reports on the use of respiration-gated radiotherapy in order to evaluate the impact of these techniques. (author)

  9. Cardiac dose sparing and avoidance techniques in breast cancer radiotherapy

    International Nuclear Information System (INIS)

    Shah, Chirag; Badiyan, Shahed; Berry, Sameer; Khan, Atif J.; Goyal, Sharad; Schulte, Kevin; Nanavati, Anish; Lynch, Melanie; Vicini, Frank A.

    2014-01-01

    Breast cancer radiotherapy represents an essential component in the overall management of both early stage and locally advanced breast cancer. As the number of breast cancer survivors has increased, chronic sequelae of breast cancer radiotherapy become more important. While recently published data suggest a potential for an increase in cardiac events with radiotherapy, these studies do not consider the impact of newer radiotherapy techniques commonly utilized. Therefore, the purpose of this review is to evaluate cardiac dose sparing techniques in breast cancer radiotherapy. Current options for cardiac protection/avoidance include (1) maneuvers that displace the heart from the field such as coordinating the breathing cycle or through prone patient positioning, (2) technological advances such as intensity modulated radiation therapy (IMRT) or proton beam therapy (PBT), and (3) techniques that treat a smaller volume around the lumpectomy cavity such as accelerated partial breast irradiation (APBI), or intraoperative radiotherapy (IORT). While these techniques have shown promise dosimetrically, limited data on late cardiac events exist due to the difficulties of long-term follow up. Future studies are required to validate the efficacy of cardiac dose sparing techniques and may use surrogates for cardiac events such as biomarkers or perfusion imaging

  10. Development of dose audits for complex treatment techniques in radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Stefanic, A. M.; Molina, L.; Vallejos, M.; Montano, G.; Zaretzky, A.; Saravi, M., E-mail: stefanic@cae.cnea.gov.ar [Centro Regional de Referencia con Patrones Secundarios para Dosimetria - CNEA, Presbitero Juan Gonzalez y Aragon 15, B1802AYA Ezeiza (Argentina)

    2014-08-15

    This work was performed in the frame of a Coordinated Research Project (CRP) with IAEA whose objective was to extend the scope of activities carried out by national TLD-based networks from dosimetry audit for rectangular radiation fields to irregular and small fields relevant to modern radiotherapy. External audit is a crucial element in QA programmes for clinical dosimetry in radiotherapy, therefore a methodology and procedures were developed and were made available for dose measurement of complex radiotherapy parameters used for cancer treatment. There were three audit steps involved in this CRP: TLD based dosimetry for irregular MLC fields for conformal radiotherapy, dosimetry in the presence of heterogeneities and 2D MLC shaped fields relevant to stereotactic radiotherapy and applicable to dosimetry for IMRT. In addition, a new development of film-based 2D dosimetry for testing dose distributions in small field geometry was included. The plan for each audit step involved a pilot study and a trial audit run with a few local hospitals. The pilot study focused on conducting and evaluation of the audit procedures with all participants. The trial audit run was the running of the audit procedures by the participants to test them with a few local radiotherapy hospitals. This work intends to provide audits which are much nearer clinical practice than previous audits as they involve significant testing of Tps methods, as well as verifications to determinate whether hospitals can correctly calculate dose delivery in radiation treatments. (author)

  11. Development of dose audits for complex treatment techniques in radiotherapy

    International Nuclear Information System (INIS)

    Stefanic, A. M.; Molina, L.; Vallejos, M.; Montano, G.; Zaretzky, A.; Saravi, M.

    2014-08-01

    This work was performed in the frame of a Coordinated Research Project (CRP) with IAEA whose objective was to extend the scope of activities carried out by national TLD-based networks from dosimetry audit for rectangular radiation fields to irregular and small fields relevant to modern radiotherapy. External audit is a crucial element in QA programmes for clinical dosimetry in radiotherapy, therefore a methodology and procedures were developed and were made available for dose measurement of complex radiotherapy parameters used for cancer treatment. There were three audit steps involved in this CRP: TLD based dosimetry for irregular MLC fields for conformal radiotherapy, dosimetry in the presence of heterogeneities and 2D MLC shaped fields relevant to stereotactic radiotherapy and applicable to dosimetry for IMRT. In addition, a new development of film-based 2D dosimetry for testing dose distributions in small field geometry was included. The plan for each audit step involved a pilot study and a trial audit run with a few local hospitals. The pilot study focused on conducting and evaluation of the audit procedures with all participants. The trial audit run was the running of the audit procedures by the participants to test them with a few local radiotherapy hospitals. This work intends to provide audits which are much nearer clinical practice than previous audits as they involve significant testing of Tps methods, as well as verifications to determinate whether hospitals can correctly calculate dose delivery in radiation treatments. (author)

  12. Development of three-dimensional radiotherapy techniques in breast cancer

    Science.gov (United States)

    Coles, Charlotte E.

    Radiotherapy following conservation surgery decreases local relapse and death from breast cancer. Currently, the challenge is to minimise the morbidity caused by this treatment without losing efficacy. Despite many advances in radiation techniques in other sites of the body, the majority of breast cancer patients are still planned and treated using 2-dimensional simple radiotherapy techniques. In addition, breast irradiation currently consumes 30% of the UK's radiotherapy workload. Therefore, any change to more complex treatment should be of proven benefit. The primary objective of this research is to develop and evaluate novel radiotherapy techniques to decrease irradiation of normal structures and improve localisation of the tumour bed. I have developed a forward-planned intensity modulated (IMRT) breast radiotherapy technique, which has shown improved dosimetry results compared to standard breast radiotherapy. Subsequently, I have developed and implemented a phase III randomised controlled breast IMRT trial. This National Cancer Research Network adopted trial will answer an important question regarding the clinical benefit of breast IMRT. It will provide DNA samples linked with high quality clinical outcome data, for a national translational radiogenomics study investigating variation in normal tissue toxicity. Thus, patients with significant late normal tissue side effects despite good dose homogeneity will provide the best model for finding differences due to underlying genetics. I evaluated a novel technique using high definition free-hand 3-dimensional (3D) ultrasound in a phantom study, and the results suggested that this is an accurate and reproducible method for tumour bed localisation. I then compared recognised methods of tumour bed localisation with the 3D ultrasound method in a clinical study. The 3D ultrasound technique appeared to accurately represent the shape and spatial position of the tumour cavity. This tumour bed localisation research

  13. The impact of induction chemotherapy on the dosimetric parameters of subsequent radiotherapy: an investigation of 30 consecutive patients with locally-advanced non-small cell lung cancer and modern radiation planning techniques

    International Nuclear Information System (INIS)

    Grant, Jonathan D; Sobremonte, Angela; Hillebrandt, Evangeline; Allen, Pamela K; Gomez, Daniel R

    2015-01-01

    To investigate the influence of induction chemotherapy (ICT) on dosimetric outcomes in patients with inoperable non-small cell lung cancer (NSCLC) treated with definitive chemoradiation (CRT). 30 patients with inoperable stage II-III NSCLC treated with 2–4 cycles of ICT followed by definitive CRT to ≥ 60 Gy were selected. Tumor response to chemotherapy was scored by RECIST criteria. Treatment plans based on tumor extent prior to chemotherapy were generated based on equivalent planning constraints and techniques as the original post-chemotherapy plans. Dosimetric parameters predictive of toxicity for lung, esophagus, heart, and spinal cord were compared amongst the pre- and post-ICT plans. The majority of patients (70%) experienced an overall reduction in GTV size between the pre-ICT imaging and the time of simulation. Comparing pre-and post-ICT diagnostic imaging, 5 patients met the RECIST criteria for response, 23 were classified as stable, and 2 experienced disease progression on diagnostic imaging. Despite a significantly reduced GTV size in the post-ICT group, no systematic improvements in normal tissue doses were seen amongst the entire cohort. This result persisted amongst the subgroup of patients with larger pre-ICT GTV tumor volumes (>100 cc 3 ). Among patients with RECIST-defined response, a significant reduction in lung mean dose (1.9 Gy absolute, median 18.2 Gy to 16.4 Gy, p = 0.04) and V 20, the percentage of lung receiving 20 Gy (3.1% absolute, median 29.3% to 26.3%, p = 0.04) was observed. In the non-responding group of patients, an increased esophageal V 50 was found post-chemotherapy (median 28.9% vs 30.1%, p = 0.02). For patients classified as having a response by RECIST to ICT, modest improvements in V 20 and mean lung dose were found. However, these benefits were not realized for the cohort as a whole or for patients with larger tumors upfront. Given the variability of tumor response to ICT, the a priori impact of induction chemotherapy to

  14. Radiotherapy

    International Nuclear Information System (INIS)

    Zedgenidze, G.A.; Kulikov, V.A.; Mardynskij, Yu.S.

    1984-01-01

    The technique for roentgenotopometric and medicamentous preparation of patients for radiotherapy has been reported in detail. The features of planning and performing of remote, intracavitary and combined therapy in urinary bladder cancer are considered. The more effective methods of radiotherapy have been proposed taking into account own experience as well as literature data. The comparative evaluation of treatment results and prognosis are given. Radiation pathomorphism of tumors and tissues of urinary bladder is considered in detail. The problems of diagnosis, prophylaxis and treatment of complications following radiodiagnosis and radiotherapy in patients with urinary bladder cancer are illustrated widely

  15. Technological advances in radiotherapy of rectal cancer

    DEFF Research Database (Denmark)

    Appelt, Ane L; Sebag-Montefiore, David

    2016-01-01

    PURPOSE OF REVIEW: This review summarizes the available evidence for the use of modern radiotherapy techniques for chemoradiotherapy for rectal cancer, with specific focus on intensity-modulated radiotherapy (IMRT) and volumetric arc therapy (VMAT) techniques. RECENT FINDINGS: The dosimetric...

  16. Dosimetric comparison of field in field intensity-modulated radiotherapy technique with conformal radiotherapy techniques in breast cancer

    International Nuclear Information System (INIS)

    Ercan, T.; Alco, G.; Zengin, F.; Atilla, S.; Dincer, M.; Igdem, S.; Okkan, S.

    2010-01-01

    The aim of this study was to be able to implement the field-in-field intensity-modulated radiotherapy (FiF) technique in our daily practice for breast radiotherapy. To do this, we performed a dosimetric comparison. Treatment plans were produced for 20 consecutive patients. FiF plans and conformal radiotherapy (CRT) plans were compared for doses in the planning target volume (PTV), the dose homogeneity index (DHI), doses in irradiated soft tissue outside the target volume (SST), ipsilateral lung and heart doses for left breast irradiation, and the monitor unit counts (MU) required for treatment. Averaged values were compared using Student's t-test. With FiF, the DHI is improved 7.0% and 5.7%, respectively (P<0.0001) over the bilateral and lateral wedge CRT techniques. When the targeted volumes received 105% and 110% of the prescribed dose in the PTV were compared, significant decreases are found with the FiF technique. With the 105% dose, the SST, heart, and ipsilateral lung doses and the MU counts were also significantly lower with the FiF technique. The FiF technique, compared to CRT, for breast radiotherapy enables significantly better dose distribution in the PTV. Significant differences are also found for soft tissue volume, the ipsilateral lung dose, and the heart dose. Considering the decreased MUs needed for treatment, the FiF technique is preferred over tangential CRT. (author)

  17. New quality assurance program integrating ''modern radiotherapy'' within the German Hodgkin Study Group

    Energy Technology Data Exchange (ETDEWEB)

    Kriz, J.; Haverkamp, U.; Eich, H.T. [University of Muenster, Department of Radiation Oncology, Muenster (Germany); Baues, C.; Marnitz-Schulze, S. [University of Cologne, Department of Radiation Oncology, Koeln (Germany); Engenhart-Cabillic, R. [University of Marburg, Department of Radiation Oncology, Marburg (Germany); Herfarth, K. [University of Heidelberg, Department of Radiation Oncology, Heidelberg (Germany); Lukas, P. [University of Innsbruck, Department of Radiation Oncology, Innsbruck (Austria); Schmidberger, H. [University of Mainz, Department of Radiation Oncology, Mainz (Germany); Fuchs, M.; Engert, A. [University of Cologne, Department of Internal Medicine, Koeln (Germany)

    2017-02-15

    Field design changed substantially from extended-field RT (EF-RT) to involved-field RT (IF-RT) and now to involved-node RT (IN-RT) and involved-site RT (IS-RT) as well as treatment techniques in radiotherapy (RT) of Hodgkin's lymphoma (HL). The purpose of this article is to demonstrate the establishment of a quality assurance program (QAP) including modern RT techniques and field designs within the German Hodgkin Study Group (GHSG). In the era of modern conformal RT, this QAP had to be fundamentally adapted and a new evaluation process has been intensively discussed by the radiotherapeutic expert panel of the GHSG. The expert panel developed guidelines and criteria to analyse ''modern'' field designs and treatment techniques. This work is based on a dataset of 11 patients treated within the sixth study generation (HD16-17). To develop a QAP of ''modern RT'', the expert panel defined criteria for analysing current RT procedures. The consensus of a modified QAP in ongoing and future trials is presented. With this schedule, the QAP of the GHSG could serve as a model for other study groups. (orig.) [German] Nicht nur die Zielvolumendefinitionen haben sich von der Extended-Field- (EF-RT) ueber die Involved-Field- (IF-RT) bis zur Involved-Node- (IN-RT) und Involved-Site-Radiotherapie (IS-RT) weiterentwickelt. Auch die Radiotherapie(RT)-Techniken in der Behandlung von Patienten mit Hodgkin-Lymphom haben Aenderungen erfahren. Wir moechten aufzeigen, wie die Arbeit des Qualitaetssicherungsprogramms (QAP) innerhalb der Deutschen Hodgkin Studiengruppe (German Hodgkin Study Group [GHSG]) in der Aera der ''modernen RT'' hinsichtlich intensitaetsmodulierter RT (IMRT) und bildgefuehrter RT (IGRT), aber auch hinsichtlich moderner Felddefinitionen wie bei der IN-RT angepasst wurde. In der Aera der ''modernen RT'' wurde das QAP vom radiotherapeutischen Expertenpanel der GHSG im Rahmen einiger

  18. Modern Cryptanalysis Techniques for Advanced Code Breaking

    CERN Document Server

    Swenson, Christopher

    2008-01-01

    As an instructor at the University of Tulsa, Christopher Swenson could find no relevant text for teaching modern cryptanalysis?so he wrote his own. This is the first book that brings the study of cryptanalysis into the 21st century. Swenson provides a foundation in traditional cryptanalysis, examines ciphers based on number theory, explores block ciphers, and teaches the basis of all modern cryptanalysis: linear and differential cryptanalysis. This time-honored weapon of warfare has become a key piece of artillery in the battle for information security.

  19. Combining Targeted Agents With Modern Radiotherapy in Soft Tissue Sarcomas

    Science.gov (United States)

    Wong, Philip; Houghton, Peter; Kirsch, David G.; Finkelstein, Steven E.; Monjazeb, Arta M.; Xu-Welliver, Meng; Dicker, Adam P.; Ahmed, Mansoor; Vikram, Bhadrasain; Teicher, Beverly A.; Coleman, C. Norman; Machtay, Mitchell; Curran, Walter J.

    2014-01-01

    Improved understanding of soft-tissue sarcoma (STS) biology has led to better distinction and subtyping of these diseases with the hope of exploiting the molecular characteristics of each subtype to develop appropriately targeted treatment regimens. In the care of patients with extremity STS, adjunctive radiation therapy (RT) is used to facilitate limb and function, preserving surgeries while maintaining five-year local control above 85%. In contrast, for STS originating from nonextremity anatomical sites, the rate of local recurrence is much higher (five-year local control is approximately 50%) and a major cause of death and morbidity in these patients. Incorporating novel technological advancements to administer accurate RT in combination with novel radiosensitizing agents could potentially improve local control and overall survival. RT efficacy in STS can be increased by modulating biological pathways such as angiogenesis, cell cycle regulation, cell survival signaling, and cancer-host immune interactions. Previous experiences, advancements, ongoing research, and current clinical trials combining RT with agents modulating one or more of the above pathways are reviewed. The standard clinical management of patients with STS with pretreatment biopsy, neoadjuvant treatment, and primary surgery provides an opportune disease model for interrogating translational hypotheses. The purpose of this review is to outline a strategic vision for clinical translation of preclinical findings and to identify appropriate targeted agents to combine with radiotherapy in the treatment of STS from different sites and/or different histology subtypes. PMID:25326640

  20. Predicting radiotherapy outcomes using statistical learning techniques

    International Nuclear Information System (INIS)

    El Naqa, Issam; Bradley, Jeffrey D; Deasy, Joseph O; Lindsay, Patricia E; Hope, Andrew J

    2009-01-01

    Radiotherapy outcomes are determined by complex interactions between treatment, anatomical and patient-related variables. A common obstacle to building maximally predictive outcome models for clinical practice is the failure to capture potential complexity of heterogeneous variable interactions and applicability beyond institutional data. We describe a statistical learning methodology that can automatically screen for nonlinear relations among prognostic variables and generalize to unseen data before. In this work, several types of linear and nonlinear kernels to generate interaction terms and approximate the treatment-response function are evaluated. Examples of institutional datasets of esophagitis, pneumonitis and xerostomia endpoints were used. Furthermore, an independent RTOG dataset was used for 'generalizabilty' validation. We formulated the discrimination between risk groups as a supervised learning problem. The distribution of patient groups was initially analyzed using principle components analysis (PCA) to uncover potential nonlinear behavior. The performance of the different methods was evaluated using bivariate correlations and actuarial analysis. Over-fitting was controlled via cross-validation resampling. Our results suggest that a modified support vector machine (SVM) kernel method provided superior performance on leave-one-out testing compared to logistic regression and neural networks in cases where the data exhibited nonlinear behavior on PCA. For instance, in prediction of esophagitis and pneumonitis endpoints, which exhibited nonlinear behavior on PCA, the method provided 21% and 60% improvements, respectively. Furthermore, evaluation on the independent pneumonitis RTOG dataset demonstrated good generalizabilty beyond institutional data in contrast with other models. This indicates that the prediction of treatment response can be improved by utilizing nonlinear kernel methods for discovering important nonlinear interactions among model

  1. Analysis of second malignancies after modern radiotherapy versus prostatectomy for localized prostate cancer

    International Nuclear Information System (INIS)

    Huang Jiayi; Kestin, Larry L.; Ye, Hong; Wallace, Michelle; Martinez, Alvaro A.; Vicini, Frank A.

    2011-01-01

    Purpose: To clarify the risk of developing second primary cancers (SPCs) after radiotherapy (RT) versus prostatectomy for localized prostate cancer (PCa) in the modern era. Methods: The RT cohort consisted of 2120 patients matched on a 1:1 basis with surgical patients according to age and follow-up time. RT techniques consisted of conventional or two-dimensional RT (2DRT, 36%), three-dimensional conformal RT and/or intensity modulated RT (3DCRT/IMRT, 29%), brachytherapy (BT, 16%), and a combination of 2DRT and BT (BT boost, 19%). Results: The overall SPC risk was not significantly different between the matched-pair (HR 1.14, 95% CI 0.94-1.39), but the risk became significant >5 years or >10 years after RT (HR 1.86, 95% CI 1.36-2.55; HR 4.94, 95% CI 2.18-11.2, respectively). The most significant sites of increased risk were bladder, lymphoproliferative, and sarcoma. Of the different RT techniques, only 2DRT was associated with a significantly higher risk (HR 1.76, 95% CI 1.32-2.35), but not BT boost (HR 0.83, 95% CI 0.50-1.38), 3DCRT/IMRT (HR 0.81, 95% CI 0.55-1.21), or BT (HR 0.53, 95% CI 0.28-1.01). Conclusions: Radiation-related SPC risk varies depending on the RT technique and may be reduced by using BT, BT boost, or 3DCRT/IMRT.

  2. Real analysis modern techniques and their applications

    CERN Document Server

    Folland, Gerald B

    1999-01-01

    An in-depth look at real analysis and its applications-now expanded and revised.This new edition of the widely used analysis book continues to cover real analysis in greater detail and at a more advanced level than most books on the subject. Encompassing several subjects that underlie much of modern analysis, the book focuses on measure and integration theory, point set topology, and the basics of functional analysis. It illustrates the use of the general theories and introduces readers to other branches of analysis such as Fourier analysis, distribution theory, and probability theory.This edi

  3. Proceedings of the International Conference on Modern Radiotherapy. Advances and Challenges in Radiation Protection of Patients

    International Nuclear Information System (INIS)

    2009-12-01

    The use of ionizing radiation in medicine has led to major improvements in the diagnosis and treatment of human diseases. While bringing new benefits for cancer treatment, modern radiotherapy also poses new challenges in terms of radiation protection of patients. Prevention of radiotherapy incidents and accidents is a major issue in this area. In December 2009, the French Nuclear Safety Authority (ASN) organised the 1. international conference on radiation protection of patients in radiotherapy. The major objective of the conference was to provide a platform for exchanging experience, and reviewing the actions implemented to improve the radiation safety in radiotherapy both at national and international level. The expected result was: - to reach a consensus about the necessity to strengthen existing international actions for prevention of incidents and accidents, - to set up an international cooperation to improve management for overexposed patients, - to outline a strategy for strengthening regulation, - to contribute to the elaboration of an international scale to rate patient related events for communication and reporting purpose. 360 delegates from 50 countries across the world participated at the 3-day conference. 41 presentations were made and 67 posters were displayed. The conference brought together a broad spectrum of expertise: scientists, health professionals, medical devices manufacturers, risk management specialists, radiation protection experts, representatives from Radiation Protection and Health Authorities as well as patient's associations. The programme covered both scientific and medical issues, such as patient sensitivity to ionising radiation and the treatment of complications. It also provided scope to discuss the benefits and risks of modern radiotherapy and to explore treatment safety issues from various perspectives, including human resources, expertise, education and training along with control and prevention strategies. The conference

  4. Radiotherapy

    International Nuclear Information System (INIS)

    Wannenmacher, M.; Debus, J.; Wenz, F.

    2006-01-01

    The book is focussed on the actual knowledge on the clinical radiotherapy and radio-oncology. Besides fundamental and general contributions specific organ systems are treated in detail. The book contains the following contributions: Basic principles, radiobiological fundamentals, physical background, radiation pathology, basics and technique of brachytherapy, methodology and technique of the stereotactic radiosurgery, whole-body irradiation, operative radiotherapy, hadron therapy, hpyerthermia, combined radio-chemo-therapy, biometric clinical studies, intensity modulated radiotherapy, side effects, oncological diagnostics; central nervous system and sense organs, head-neck carcinomas, breast cancer, thorax organs, esophagus carcinoma, stomach carcinoma, pancreas carcinoma, heptabiliary cancer and liver metastases, rectal carcinomas, kidney and urinary tract, prostate carcinoma, testicular carcinoma, female pelvis, lymphatic system carcinomas, soft tissue carcinoma, skin cancer, bone metastases, pediatric tumors, nonmalignant diseases, emergency in radio-oncology, supporting therapy, palliative therapy

  5. Compensation techniques in NIRS proton beam radiotherapy

    International Nuclear Information System (INIS)

    Akanuma, A.; Majima, H.; Furukawa, S.

    1982-01-01

    Proton beam has the dose distribution advantage in radiation therapy, although it has little advantage in biological effects. One of the best advantages is its sharp fall off of dose after the peak. With proton beam, therefore, the dose can be given just to cover a target volume and potentially no dose is delivered thereafter in the beam direction. To utilize this advantage, bolus techniques in conjunction with CT scanning are employed in NIRS proton beam radiation therapy planning. A patient receives CT scanning first so that the target volume can be clearly marked and the radiation direction and fixation method can be determined. At the same time bolus dimensions are calculated. The bolus frames are made with dental paraffin sheets according to the dimensions. The paraffin frame is replaced with dental resin. Alginate (a dental impression material with favorable physical density and skin surface contact) is now employed for the bolus material. With fixation device and bolus on, which are constructed individually, the patient receives CT scanning again prior to a proton beam treatment in order to prove the devices are suitable. Alginate has to be poured into the frame right before each treatments. Further investigations are required to find better bolus materials and easier construction methods

  6. Compensation techniques in NIRS proton beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Akanuma, A. (Univ. of Tokyo, Japan); Majima, H.; Furukawa, S.

    1982-09-01

    Proton beam has the dose distribution advantage in radiation therapy, although it has little advantage in biological effects. One of the best advantages is its sharp fall off of dose after the peak. With proton beam, therefore, the dose can be given just to cover a target volume and potentially no dose is delivered thereafter in the beam direction. To utilize this advantage, bolus techniques in conjunction with CT scanning are employed in NIRS proton beam radiation therapy planning. A patient receives CT scanning first so that the target volume can be clearly marked and the radiation direction and fixation method can be determined. At the same time bolus dimensions are calculated. The bolus frames are made with dental paraffin sheets according to the dimensions. The paraffin frame is replaced with dental resin. Alginate (a dental impression material with favorable physical density and skin surface contact) is now employed for the bolus material. With fixation device and bolus on, which are constructed individually, the patient receives CT scanning again prior to a proton beam treatment in order to prove the devices are suitable. Alginate has to be poured into the frame right before each treatments. Further investigations are required to find better bolus materials and easier construction methods.

  7. Parotid gland sparing radiotherapy technique using 3-D conformal radiotherapy for nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Lim, Ji Hoon; Kim, Gwi Eon; Keum, Ki Chang; Suh, Chang Ok; Lee, Sang Wook; Park, Hee Chul; Cho, Jae Ho; Chang, Sei Kyung; Loh, Juhn Kyu

    2000-01-01

    Although using the high energy photon beam with conventional parallel-opposed beams radio-therapy for nasopgaryngeal carcinoma, radiation-induced xerostomia is a troublesome problem for patients. We conducted this study to explore a new parotid gland sparing technique in 3-D conformal radiotherapy (3-DCRT) in an effort to prevent the radiation-induced xerostomia. We performed three different planning for four clinically node-negative nasopharyngeal cancer patients with different location of tumor(intracranial extension, nasal cavity extension, oropharyngeal extension, parapharyngeal extension), and intercompared the plans. Total prescription dose was 70.2 Gy to the isocenter. For plan-A, 2-D parallel opposing fields, a conventional radiotherapy technique, were employed. For plan-B, 2-D parallel opposing fields were used up until 54 Gy and afterwards 3-D non-coplanar beams were used. For plan-C, the new technique, 54Gy was delivered by 3-D conformal 3-port beams (AP and both lateral ports with wedge compensator, shielding both superficial lobes of parotid glands at the AP beam using BEV) from the beginning of the treatment and early spinal cord block (at 36 Gy) was performed. And bilateral posterior necks were treated with electron after 36 Gy. After 54 Gy, non-coplanar beams were used for cone-down plan. We intercompared dose statistics (Dmax, Dmin, Dmean, D95, D05, V95, V05, Volume receiving 46 Gy) and dose volume histograms (DVH) of tumor and normal tissues and NTCP values of parotid glands for the above three plans. For all patients, the new technique (plan-C) was comparable or superior to the other plans in target volume isodose distribution and dose statistics and it has more homogenous target volume coverage. The new technique was most superior to the other plans in parotid glands sparing (volume receiving 46 Gy: 100, 98, 69% for each plan-A, B and C). And it showed the lowest NTCP value of parotid glands in all patients (range of NTCP; 96-100%, 79-99%, 51

  8. Evaluation of conformal radiotherapy techniques through physics and biologic criteria

    International Nuclear Information System (INIS)

    Bloch, Jonatas Carrero

    2012-01-01

    In the fight against cancer, different irradiation techniques have been developed based on technological advances and aiming to optimize the elimination of tumor cells with the lowest damage to healthy tissues. The radiotherapy planning goal is to establish irradiation technical parameters in order to achieve the prescribed dose distribution over the treatment volumes. While dose prescription is based on radiosensitivity of the irradiated tissues, the physical calculations on treatment planning take into account dosimetric parameters related to the radiation beam and the physical characteristics of the irradiated tissues. To incorporate tissue's radiosensitivity into radiotherapy planning calculations can help particularize treatments and establish criteria to compare and elect radiation techniques, contributing to the tumor control and the success of the treatment. Accordingly, biological models of cellular response to radiation have to be well established. This work aimed to study the applicability of using biological models in radiotherapy planning calculations to aid evaluating radiotherapy techniques. Tumor control probability (TCP) was studied for two formulations of the linear-quadratic model, with and without repopulation, as a function of planning parameters, as dose per fraction, and of radiobiological parameters, as the α/β ratio. Besides, the usage of biological criteria to compare radiotherapy techniques was tested using a prostate planning simulated with Monte Carlo code PENELOPE. Afterwards, prostate planning for five patients from the Hospital das Clinicas da Faculdade de Medicina de Ribeirao Preto, USP, using three different techniques were compared using the tumor control probability. In that order, dose matrices from the XiO treatment planning system were converted to TCP distributions and TCP-volume histograms. The studies performed allow the conclusions that radiobiological parameters can significantly influence tumor control

  9. Integration of molecular imaging in treatment planning and delivery of modern radiotherapy

    International Nuclear Information System (INIS)

    Jacob, V.; Wilkens, J.J.

    2011-01-01

    Among various imaging modalities currently available, positron emission tomography (PET) has the potential to visualize processes on a molecular level. Molecular imaging, often also referred to as functional or biological imaging, brought a new dimension to diagnostics and therapy of cancer by providing images of metabolism and other processes in the human body and in tumours. PET was first applied for diagnostics and staging of various tumours with high diagnostic precision. Modern radiotherapy asks increasingly for individualized treatment strategies, taking molecular imaging into account. Technical developments over the last years, in particular methods to register various imaging modalities within software packages for treatment planning and target delineation, facilitated the use of PET imaging in radiotherapy. In order to exploit the full potential of modern high-precision radiotherapy, exact imaging procedures are necessary, for example for precise target volume definition. In the long run, concepts employing an inhomogeneous dose prescription based on biological imaging may become routine in clinical applications, leading to individualized, biologically adaptive therapy. (orig.)

  10. Modern insect control: Nuclear techniques and biotechnology

    International Nuclear Information System (INIS)

    1988-01-01

    The Symposium dealt primarily with genetic methods of insect control, including sterile insect technique (SIT), F 1 sterility, compound chromosomes, translocations and conditional lethals. Research and development activities on various aspects of these control technologies were reported by participants during the Symposium. Of particular interest was development of F 1 sterility as a practical method of controlling pest Lepidoptera. Genetic methods of insect control are applicable only on an area wide basis. They are species specific and thus do not reduce populations of beneficial insects or cause other environmental problems. Other papers presented reported on the potential use of radiation as a quarantine treatment for commodities in international trade and the use of radioisotopes as ''tags'' in studying insects

  11. The progress in radiotherapy techniques and it's clinical implications

    International Nuclear Information System (INIS)

    Reinfuss, M.; Walasek, T.; Byrski, E.; Blecharz, P.

    2011-01-01

    Three modem radiotherapy techniques were introduced into clinical practice at the onset of the 21 st century - stereotactic radiation therapy (SRT), proton therapy and carbon-ion radiotherapy. Our paper summarizes the basic principles of physics, as well as the technical reqirements and clinical indications for those techniques. SRT is applied for intracranial diseases (arteriovenous malformations, acoustic nerve neuromas, brain metastases, skull base tumors) and in such cases it is referred to as stereotactic radiosurgery (SRS). Techniques used during SRS include GammaKnife, CyberKnife and dedicated linacs. SRT can also be applied for extracranial disease (non-small cell lung cancer, lung metastases, spinal and perispinal tumors, primary liver tumors, breast cancer, pancreatic tumors, prostate cancer, head and neck tumors) and in such cases it is referred to as stereotactic body radiation therapy (SBRT). Eye melanomas, skull base and cervical spine chordomas and chordosarcomas, as well as childhood neoplasms, are considered to be the classic indications for proton therapy. Clinical trials are currently conducted to investigate the usefulness of proton beam in therapy of non-small cell lung cancer, prostate cancer, head and neck tumors, primary liver and oesophageal cancer Carbon-ion radiotherapy is presumed to be more advantageous than proton therapy because of its higher relative biological effectiveness (RBE) and possibility of real-time control of the irradiated volume under PET visualization. The basic indications for carbon-ion therapy are salivary glands neoplasms, selected types of soft tissue and bone sarcomas, skull base chordomas and chordosarcomas, paranasal sinus neoplasms, primary liver cancers and inoperable rectal adenocarcinoma recurrences. (authors)

  12. Current role of the radiographers in imaging diagnostics, nuclear medicine and radiotherapy in modern departments

    International Nuclear Information System (INIS)

    Karidova, S.; Velkova, K.; Panamska, K.; Petkova, K.

    2006-01-01

    Full text: In the communication we set out to focus the attention of the medical staff and the public on the place and the constantly growing role (relative burden) of the radiographers in imaging diagnostics, nuclear medicine and radiotherapy in the field of modern medicine. The advanced radiographers level and rapid development of the contemporary equipment and apparatuses used in imaging diagnostics, nuclear medicine and radiotherapy, as well as the methods of their utilization, presuppose very good and constantly improving theoretical and practical training of the imaging technician. The radiographer fulfills responsible tasks under the guidance of the physician or independently and bears specific responsibilities. Having mastered the fundamentals of radiation protection, the imaging technician protects both himself and the patient from the impact of ionizing radiation. To be able to fulfill his/her constantly increasing duties and obligations, the imaging radiographer has acquired wide knowledge of general education subjects, subjects of general medicine and special subjects. The radiographer has a good knowledge of Latin and a modern foreign language, and he is also computer literate so as to be able to cope with the widely spread visualizing methods. The radiographer acquires additional post-graduate training to work in narrowly specialized fields as well as to improve his/her qualifications

  13. Dosimetric comparison of intensity modulated radiotherapy techniques and standard wedged tangents for whole breast radiotherapy

    International Nuclear Information System (INIS)

    Fong, Andrew; Bromley, Regina; Beat, Mardi; Vien, Din; Dineley, Jude; Morgan, Graeme

    2009-01-01

    Full text: Prior to introducing intensity modulated radiotherapy (IMRT) for whole breast radiotherapy (WBRT) into our department we undertook a comparison of the dose parameters of several IMRT techniques and standard wedged tangents (SWT). Our aim was to improve the dose distribution to the breast and to decrease the dose to organs at risk (OAR): heart, lung and contralateral breast (Contra Br). Treatment plans for 20 women (10 right-sided and 10 left-sided) previously treated with SWT for WBRT were used to compare (a) SWT; (b) electronic compensators IMRT (E-IMRT); (c) tangential beam IMRT (T-IMRT); (d) coplanar multi-field IMRT (CP-IMRT); and (e) non-coplanar multi-field IMRT (NCP-IMRT). Plans for the breast were compared for (i) dose homogeneity (DH); (ii) conformity index (CI); (iii) mean dose; (iv) maximum dose; (v) minimum dose; and dose to OAR were calculated (vi) heart; (vii) lung and (viii) Contra Br. Compared with SWT, all plans except CP-IMRT gave improvement in at least two of the seven parameters evaluated. T-IMRT and NCP-IMRT resulted in significant improvement in all parameters except DH and both gave significant reduction in doses to OAR. As on initial evaluation NCP-IMRT is likely to be too time consuming to introduce on a large scale, T-IMRT is the preferred technique for WBRT for use in our department.

  14. Quality assurance patient positioning and immobilization techniques for radiotherapy

    International Nuclear Information System (INIS)

    Wadhawan, G.S.; Negi, P.S.; Anand, A.K.; Munjal, R.K.; Sinha, S.N.

    2007-01-01

    Over the last decade the ability to precisely deliver radiotherapy (RT) treatments has advanced dramatically. Imaging technology has evolved to facilitate better target delineation during treatment planning. Treatment delivery techniques have advanced to enable intensity modulated RT (IMRT) treatments that provide radiation doses, tightly conforming to the target volumes. These advancements have been driven by the dual goals of maximizing the radiation dose to the tumor volume while minimizing the radiation dose to the surrounding normal tissue. The ability to expand the use of these techniques to deliver higher doses in fewer fractions is now largely limited by changes in the tumor position from day to day and even during treatment and so the ability to precisely locate the tumor throughout the course of RT has become a topic of concern

  15. Respiratory gating and multi field technique radiotherapy for esophageal cancer

    International Nuclear Information System (INIS)

    Ohta, Atsushi; Kaidu, Motoki; Tanabe, Satoshi

    2017-01-01

    To investigate the effects of a respiratory gating and multi field technique on the dose-volume histogram (DVH) in radiotherapy for esophageal cancer. Twenty patients who underwent four-dimensional computed tomography for esophageal cancer were included. We retrospectively created the four treatment plans for each patient, with or without the respiratory gating and multi field technique: No gating-2-field, No gating-4-field, Gating-2-field, and Gating-4-field plans. We compared the DVH parameters of the lung and heart in the No gating-2-field plan with the other three plans.Result In the comparison of the parameters in the No gating-2-field plan, there are significant differences in the Lung V 5Gy , V 20Gy , mean dose with all three plans and the Heart V 25Gy -V 40Gy with Gating-2-field plan, V 35Gy , V 40Gy , mean dose with No Gating-4-field plan and V 30Gy -V 40Gy , and mean dose with Gating-4-field plan. The lung parameters were smaller in the Gating-2-field plan and larger in the No gating-4-field and Gating-4-field plans. The heart parameters were all larger in the No gating-2-field plan. The lung parameters were reduced by the respiratory gating technique and increased by the multi field technique. The heart parameters were reduced by both techniques. It is important to select the optimal technique according to the risk of complications. (author)

  16. Daily-diary evaluated side-effects of conformal versus conventional prostatic cancer radiotherapy technique

    International Nuclear Information System (INIS)

    Widmark, A.; Fransson, P.; Franzen, L.; Littbrand, B.; Henriksson, R.

    1997-01-01

    Conventional 4-field box radiotherapy technique induces high morbidity for patients with localized prostatic cancer. Using a patient daily diary, the present study compared side-effects after conventional radiotherapy with conformal radiotherapy for prostate cancer. Fifty-eight patients treated with the conventional technique (with or without sucralfate) were compared with 72 patients treated with conformal technique. The patient groups were compared with an age-matched control population. Patients treated with conformal technique were also evaluated regarding acute and late urinary problems. Results showed that patients treated with conformal technique reported significantly fewer side-effects as compared with conventional technique. Patients treated with sucralfate also showed slightly decreased intestinal morbidity in comparison to non-sucralfate group. Acute and late morbidity evaluated by the patients was decreased after conformal radiotherapy as compared with the conventional technique. Sucralfate may be of value if conformal radiotherapy is used for dose escalation in prostatic cancer patients. (orig.)

  17. Prospective approaches for risk analysis in modern radiotherapy: the Italian experience and the contribution of medical physicists

    International Nuclear Information System (INIS)

    Begnozzi, L.; Cantone, M.C.; Veronese, I.; Longobardi, B.

    2014-01-01

    In the last few years there has been significant development of radiation therapy (RT) equipment with advanced imaging and delivery techniques, as well as treatment planning systems. From this perspective, proactive approaches for risk assessment were identified as a powerful tool in modern radiation oncology. A multidisciplinary working group (WG) has been established in the framework of the Italian association for medical physics (AIFM) to promote the use of prospective approaches in the radiotherapy scientific community. This paper describes the main actions carried out by the WG in order to collect information about the engagement of Italian medical physicists in the risk management process, in reporting possible incidents in RT and in the procedures of collecting and analysing near misses. In particular, the main scope of the study was to evaluate the actual level of experience in use of proactive risk analysis tools in modern RT by medical physicists. Finally, the measures implemented by the WG in order to promote the use of such approaches, and consequently to contribute to enhancing safety and radiation protection culture in radiation oncology are described. (authors)

  18. Cardiac avoidance in breast radiotherapy: a comparison of simple shielding techniques with intensity-modulated radiotherapy

    International Nuclear Information System (INIS)

    Landau, David; Adams, Elizabeth J.; Webb, Steve; Ross, Gillian

    2001-01-01

    Background and purpose: Adjuvant breast radiotherapy (RT) is now part of the routine care of patients with early breast cancer. However, analysis of the Early Breast Cancer Trialists' Collaborative suggests that patients with the lowest risk of dying of breast cancer are at significant risk of cardiac mortality due to longer relapse-free survival. Patients with a significant amount of heart in the high-dose volume have been shown to be at risk of fatal cardiac events. This study was designed to assess whether conformal planning or intensity-modulated radiotherapy (IMRT) techniques allow reduced cardiac irradiation whilst maintaining full target coverage. Material and methods: Ten patients with early breast cancer were available for computed tomography (CT) planning. Each had at least 1 cm maximum heart depth within the posterior border of conventional tangents. For each patient, plans were generated and compared using dose volume histograms for planning target volume (PTV) and organs at risk. The plans included conventional tangents with and without shielding. The shielding was designed to either completely spare the heart or to shield as much heart as possible without compromising PTV coverage. IMRT plans were also prepared using two- and four-field tangential and six-field arc-like beam arrangements. Results: PTV homogeneity was better for the tangential IMRT techniques. For all patients, cardiac irradiation was reduced by the addition of partial cardiac shielding to conventional tangents, without compromise of PTV coverage. The two- and four-field IMRT techniques also reduced heart doses. The average percentage volume of heart receiving >60% of the prescription dose was 4.4% (range 1.0-7.1%) for conventional tangents, 1.5% (0.2-3.9%) for partial shielding, 2.3% (0.5-4.6%) for the two-field IMRT technique and 2.2% (0.4-5.6%) for the four-field IMRT technique. For patients with larger maximum heart depths the four-field IMRT plan achieved greater heart sparing

  19. Modern techniques for condition monitoring of railway vehicle dynamics

    International Nuclear Information System (INIS)

    Ngigi, R W; Pislaru, C; Ball, A; Gu, F

    2012-01-01

    A modern railway system relies on sophisticated monitoring systems for maintenance and renewal activities. Some of the existing conditions monitoring techniques perform fault detection using advanced filtering, system identification and signal analysis methods. These theoretical approaches do not require complex mathematical models of the system and can overcome potential difficulties associated with nonlinearities and parameter variations in the system. Practical applications of condition monitoring tools use sensors which are mounted either on the track or rolling stock. For instance, monitoring wheelset dynamics could be done through the use of track-mounted sensors, while vehicle-based sensors are preferred for monitoring the train infrastructure. This paper attempts to collate and critically appraise the modern techniques used for condition monitoring of railway vehicle dynamics by analysing the advantages and shortcomings of these methods.

  20. Evaluation of Modern Irrigation Techniques with Brackish Water

    OpenAIRE

    Aboulila, Tarek Selim

    2012-01-01

    Modern irrigation techniques are becoming increasingly important in water-scarce countries especially in arid and semiarid regions. Higher crop production and better water use efficiency are usually achieved by drip irrigation as compared to other irrigation methods. Furthermore, by using drip irrigation simultaneously with brackish irrigation water, some of the water stress due to shortage of fresh water resources can be managed. The objective of the current study was to investigate the infl...

  1. Osteonecrosis of the sesamoid bone: contribution of modern imaging techniques

    International Nuclear Information System (INIS)

    Leleu, J.P.; Heno, P.; Rispal, P.; Joullie, M.; Laurent, F.

    1990-01-01

    We report a case of osteonecrosis of the sesamoid bone or Renander disease in a young male serviceman. Modern imaging techniques proved useful for identifying the lesion. CT scan and above all magnetic resonance imaging established the accurate diagnosis. The combination of a hypointense signal from the sesamoid bone with an effusion in the first metatarsophalangeal joint should be considered as characteristic of osteonecrosis of the sesamoid bone [fr

  2. Potential of modern sonographic techniques in paediatric uroradiology

    Energy Technology Data Exchange (ETDEWEB)

    Riccabona, Michael E-mail: michael.riccabona@kfunigraz.ac.at

    2002-08-01

    Objective: To describe the potential of modern sonographic techniques in paediatric uroradiology. Method: Ultrasound (US)--now being the primary imaging tool--has revolutionised imaging diagnostic in the urinary tract. Constant developments and technical refinements have secured the role of US in uroradiology. Colour Doppler Sonography (CDS) and innovative applications such as the transperineal approach or application of m-mode US to the urinary tract have helped to develop US from just a basic tool to a sophisticated and respected method. The ongoing introduction of new and even more sophisticated methods further enhance the sonographic potential, which shall be demonstrated by a more detailed discussion of these methods. Results: Harmonic imaging, extended field of view US, amplitude coded CDS, echo-enhanced US, and three-dimensional US as the most recent new sonographic techniques are successfully applicable to paediatric urinary tract disease. They improve sonographic diagnosis in many conditions, such as detection of vesico-ureteral reflux, renal parenchymal volume assessment, comprehensive visualisation of hydronephrosis and complex pathology, evaluation of renal perfusional disturbances or defects, superior documentation with improved comparability for follow-up, or simply by offering clearer tissue delineation and differentiation. Conclusion: Modern US techniques are successfully applicable to neonates, infants, and children, further boosting the value of US in the paediatric urinary tract. However, as handling became more sophisticated, and artefacts have to be considered, modern urosonography became not only a more powerful, but also a more demanding method, with the need for expert knowledge and dedicated training.

  3. Potential of modern sonographic techniques in paediatric uroradiology

    International Nuclear Information System (INIS)

    Riccabona, Michael

    2002-01-01

    Objective: To describe the potential of modern sonographic techniques in paediatric uroradiology. Method: Ultrasound (US)--now being the primary imaging tool--has revolutionised imaging diagnostic in the urinary tract. Constant developments and technical refinements have secured the role of US in uroradiology. Colour Doppler Sonography (CDS) and innovative applications such as the transperineal approach or application of m-mode US to the urinary tract have helped to develop US from just a basic tool to a sophisticated and respected method. The ongoing introduction of new and even more sophisticated methods further enhance the sonographic potential, which shall be demonstrated by a more detailed discussion of these methods. Results: Harmonic imaging, extended field of view US, amplitude coded CDS, echo-enhanced US, and three-dimensional US as the most recent new sonographic techniques are successfully applicable to paediatric urinary tract disease. They improve sonographic diagnosis in many conditions, such as detection of vesico-ureteral reflux, renal parenchymal volume assessment, comprehensive visualisation of hydronephrosis and complex pathology, evaluation of renal perfusional disturbances or defects, superior documentation with improved comparability for follow-up, or simply by offering clearer tissue delineation and differentiation. Conclusion: Modern US techniques are successfully applicable to neonates, infants, and children, further boosting the value of US in the paediatric urinary tract. However, as handling became more sophisticated, and artefacts have to be considered, modern urosonography became not only a more powerful, but also a more demanding method, with the need for expert knowledge and dedicated training

  4. Validation of an online replanning technique for prostate adaptive radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Peng Cheng; Chen Guangpei; Ahunbay, Ergun; Wang Dian; Lawton, Colleen; Li, X Allen, E-mail: ali@mcw.edu [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States)

    2011-06-21

    We have previously developed an online adaptive replanning technique to rapidly adapt the original plan according to daily CT. This paper reports the quality assurance (QA) developments in its clinical implementation for prostate cancer patients. A series of pre-clinical validation tests were carried out to verify the overall accuracy and consistency of the online replanning procedure. These tests include (a) phantom measurements of 22 individual patient adaptive plans to verify their accuracy and deliverability and (b) efficiency and applicability of the online replanning process. A four-step QA procedure was established to ensure the safe and accurate delivery of an adaptive plan, including (1) offline phantom measurement of the original plan, (2) online independent monitor unit (MU) calculation for a redundancy check, (3) online verification of plan-data transfer using an in-house software and (4) offline validation of actually delivered beam parameters. The pre-clinical validations demonstrate that the newly implemented online replanning technique is dosimetrically accurate and practically efficient. The four-step QA procedure is capable of identifying possible errors in the process of online adaptive radiotherapy and to ensure the safe and accurate delivery of the adaptive plans. Based on the success of this work, the online replanning technique has been used in the clinic to correct for interfractional changes during the prostate radiation therapy.

  5. Validation of an online replanning technique for prostate adaptive radiotherapy

    International Nuclear Information System (INIS)

    Peng Cheng; Chen Guangpei; Ahunbay, Ergun; Wang Dian; Lawton, Colleen; Li, X Allen

    2011-01-01

    We have previously developed an online adaptive replanning technique to rapidly adapt the original plan according to daily CT. This paper reports the quality assurance (QA) developments in its clinical implementation for prostate cancer patients. A series of pre-clinical validation tests were carried out to verify the overall accuracy and consistency of the online replanning procedure. These tests include (a) phantom measurements of 22 individual patient adaptive plans to verify their accuracy and deliverability and (b) efficiency and applicability of the online replanning process. A four-step QA procedure was established to ensure the safe and accurate delivery of an adaptive plan, including (1) offline phantom measurement of the original plan, (2) online independent monitor unit (MU) calculation for a redundancy check, (3) online verification of plan-data transfer using an in-house software and (4) offline validation of actually delivered beam parameters. The pre-clinical validations demonstrate that the newly implemented online replanning technique is dosimetrically accurate and practically efficient. The four-step QA procedure is capable of identifying possible errors in the process of online adaptive radiotherapy and to ensure the safe and accurate delivery of the adaptive plans. Based on the success of this work, the online replanning technique has been used in the clinic to correct for interfractional changes during the prostate radiation therapy.

  6. Modern techniques for studying biofilm-influenced corrosion

    International Nuclear Information System (INIS)

    Beech, I.B.

    1998-01-01

    In natural and made-made environments the presence of biofilms on surfaces of metals and their alloys influences electrochemistry at the biofilm/substratum interface, enhancing or inhibiting corrosion reactions. Due to the complexity of the biocorrosion phenomenon a range of techniques is commonly employed to study mechanisms involved. In addition to traditional methods of corrosion investigation such as electrochemical measurements and light and scanning electron microscopy observations coupled with energy dispersive X-ray analysis (EDXA) and X-ray diffraction (XRD). Modern techniques of surface science proved to be very useful in elucidating biofilm/metal interactions. Recent applications of Environmental Scanning Electron Microscopy (ESEM), Atomic Force Microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) to biocorrosion studies allowed better understanding of the biologically influenced metal deterioration process. The scope and promise of these latter techniques will be discussed and their use illustrated on practical examples. (Author)

  7. Radiotherapy

    International Nuclear Information System (INIS)

    Prosnitz, L.R.; Kapp, D.S.; Weissberg, J.B.

    1983-01-01

    This review highlights developments over the past decade in radiotherapy and attempts to summarize the state of the art in the management of the major diseases in which radiotherapy has a meaningful role. The equipment, radiobiology of radiotherapy and carcinoma of the lung, breast and intestines are highlighted

  8. Side effects after radiotherapy of age-related macular degeneration with the Nijmegen technique.

    NARCIS (Netherlands)

    Hoyng, C.B.; Tromp, A.I.; Meulendijks, C.F.M.; Leys, A.; Maazen, R.W.M. van der; Deutman, A.F.; Vingerling, J.R.

    2002-01-01

    BACKGROUND: In a randomized trial concerning radiotherapy for age-related macular degeneration, fluorescein angiograms were taken of controls and patients. In this study the frequency of side effects in eyes receiving radiotherapy with the Nijmegen technique is compared with the findings in the eyes

  9. Basic prediction techniques in modern video coding standards

    CERN Document Server

    Kim, Byung-Gyu

    2016-01-01

    This book discusses in detail the basic algorithms of video compression that are widely used in modern video codec. The authors dissect complicated specifications and present material in a way that gets readers quickly up to speed by describing video compression algorithms succinctly, without going to the mathematical details and technical specifications. For accelerated learning, hybrid codec structure, inter- and intra- prediction techniques in MPEG-4, H.264/AVC, and HEVC are discussed together. In addition, the latest research in the fast encoder design for the HEVC and H.264/AVC is also included.

  10. Selection of the optimal radiotherapy technique for locally advanced hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Lee, Ik-Jae; Seong, Jinsil; Koom, Woong-Sub; Kim, Yong-Bae; Jeon, Byeong-Chul; Kim, Joo-Ho; Han, Kwang-Hyub

    2011-01-01

    Various techniques are available for radiotherapy of hepatocellular carcinoma, including three-dimensional conformal radiotherapy, linac-based intensity-modulated radiotherapy and helical tomotherapy. The purpose of this study was to determine the optimal radiotherapy technique for hepatocellular carcinoma. Between 2006 and 2007, 12 patients underwent helical tomotherapy for locally advanced hepatocellular carcinoma. Helical tomotherapy computerized radiotherapy planning was compared with the best computerized radiotherapy planning for three-dimensional conformal radiotherapy and linac-based intensity-modulated radiotherapy for the delivery of 60 Gy in 30 fractions. Tumor coverage was assessed by conformity index, radical dose homogeneity index and moderated dose homogeneity index. Computerized radiotherapy planning was also compared according to the tumor location. Tumor coverage was shown to be significantly superior with helical tomotherapy as assessed by conformity index and moderated dose homogeneity index (P=0.002 and 0.03, respectively). Helical tomotherapy showed significantly lower irradiated liver volume at 40, 50 and 60 Gy (V40, V50 and V60, P=0.04, 0.03 and 0.01, respectively). On the contrary, the dose-volume of three-dimensional conformal radiotherapy at V20 was significantly smaller than those of linac-based intensity-modulated radiotherapy and helical tomotherapy in the remaining liver (P=0.03). Linac-based intensity-modulated radiotherapy showed better sparing of the stomach compared with helical tomotherapy in the case of separated lesions in both lobes (12.3 vs. 24.6 Gy). Helical tomotherapy showed the high dose-volume exposure to the left kidney due to helical delivery in the right lobe lesion. Helical tomotherapy achieved the best tumor coverage of the remaining normal liver. However, helical tomotherapy showed much exposure to the remaining liver at the lower dose region and left kidney. (author)

  11. Interstitial radiotherapy

    International Nuclear Information System (INIS)

    Scardino, P.T.; Bretas, F.

    1987-01-01

    The authors now have 20 years of experience with modern techniques of brachytherapy. The large number of patients treated in medical centers around the world and the widespread use of this type of radiotherapy have provided us with substantial information about the indications and contraindications, advantages and disadvantages, pitfalls and complications, as well as the results of these techniques. Although the focus of this review is the experience at Baylor using the combined technique of gold seed implantation plus external beam irradiation, the alternative forms of brachytherapy will be described and compared. The authors' intention is to provide the busy clinician with a succinct and informative review indicating the status of modern interstitial radiotherapy and describing day-to-day approach and results

  12. Proceedings of the International Conference on Modern Radiotherapy. Advances and Challenges in Radiation Protection of Patients; Actes de la conference internationale sur la radiotherapie moderne. Defis et progres dans le domaine de la radioprotection des patients

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-12-15

    The use of ionizing radiation in medicine has led to major improvements in the diagnosis and treatment of human diseases. While bringing new benefits for cancer treatment, modern radiotherapy also poses new challenges in terms of radiation protection of patients. Prevention of radiotherapy incidents and accidents is a major issue in this area. In December 2009, the French Nuclear Safety Authority (ASN) organised the 1. international conference on radiation protection of patients in radiotherapy. The major objective of the conference was to provide a platform for exchanging experience, and reviewing the actions implemented to improve the radiation safety in radiotherapy both at national and international level. The expected result was: - to reach a consensus about the necessity to strengthen existing international actions for prevention of incidents and accidents, - to set up an international cooperation to improve management for overexposed patients, - to outline a strategy for strengthening regulation, - to contribute to the elaboration of an international scale to rate patient related events for communication and reporting purpose. 360 delegates from 50 countries across the world participated at the 3-day conference. 41 presentations were made and 67 posters were displayed. The conference brought together a broad spectrum of expertise: scientists, health professionals, medical devices manufacturers, risk management specialists, radiation protection experts, representatives from Radiation Protection and Health Authorities as well as patient's associations. The programme covered both scientific and medical issues, such as patient sensitivity to ionising radiation and the treatment of complications. It also provided scope to discuss the benefits and risks of modern radiotherapy and to explore treatment safety issues from various perspectives, including human resources, expertise, education and training along with control and prevention strategies. The

  13. Radiotherapy

    Directory of Open Access Journals (Sweden)

    Rema Jyothirmayi

    1999-01-01

    Full Text Available Purpose. Conservative treatment in the form of limited surgery and post-operative radiotherapy is controversial in hand and foot sarcomas, both due to poor radiation tolerance of the palm and sole, and due to technical difficulties in achieving adequate margins.This paper describes the local control and survival of 41 patients with soft tissue sarcoma of the hand or foot treated with conservative surgery and radiotherapy. The acute and late toxicity of megavoltage radiotherapy to the hand and foot are described. The technical issues and details of treatment delivery are discussed. The factors influencing local control after radiotherapy are analysed.

  14. Application of modern reliability database techniques to military system data

    International Nuclear Information System (INIS)

    Bunea, Cornel; Mazzuchi, Thomas A.; Sarkani, Shahram; Chang, H.-C.

    2008-01-01

    This paper focuses on analysis techniques of modern reliability databases, with an application to military system data. The analysis of military system data base consists of the following steps: clean the data and perform operation on it in order to obtain good estimators; present simple plots of data; analyze the data with statistical and probabilistic methods. Each step is dealt with separately and the main results are presented. Competing risks theory is advocated as the mathematical support for the analysis. The general framework of competing risks theory is presented together with simple independent and dependent competing risks models available in literature. These models are used to identify the reliability and maintenance indicators required by the operating personnel. Model selection is based on graphical interpretation of plotted data

  15. Special set-up and treatment techniques for the radiotherapy of pediatric malignancies

    International Nuclear Information System (INIS)

    Martinez, A.; Donaldson, S.S.; Bagshaw, M.A.

    1977-01-01

    The prevention of serious and long term complications of treatment have become as important a consideration in the therapy of children with malignant disease as the goal of tumor control. This balance requires meticulous treatment planning and attention to the treatment preparation and immobilization techniques when radiotherapy is administered to children. Accurate localization of tumor volume and daily reproducibility is essential for delivering precise irradiation. Four special set-up and treatment techniques which have a specific usefulness in radiotherapy for pediatric malignancies are defined and illustrated with the aid of clinical cases. They include the three point set-up, the split beam technique, the isocentric technique, and the strinking field technique

  16. External beam radiotherapy (EBRT) techniques used in breast cancer treatment to reduce cardiac exposure

    International Nuclear Information System (INIS)

    Fung, Esther; Hendry, Julie

    2013-01-01

    Radiotherapy in breast cancer treatment has been shown to reduce local recurrence and improve survival rates. However, there is a concern that breast radiotherapy can cause an increase in cardiac mortality, particularly in patients being treated for left-sided breast cancer. This review aims to investigate how cardiac exposure is minimised in breast radiotherapy and determine an optimal method for reducing cardiac dose, using literature from ScienceDirect, Medline and CINAHL. IMRT and breathing-adapted radiotherapy both reduce cardiac exposure but IMRT also increases the irradiated volume at low dose. Several issues were reported with regards to the clinical implementation of these techniques. It is suggested that inspiration breath-hold radiotherapy, is the preferred solution to minimising cardiac exposure but more research is warranted to confirm this. Long-term follow-up is required to determine dose–response relationships. Research needs to focus on breast cancer treatment as a whole in order to effectively reduce cardiac mortality.

  17. Modern trends: analytical chemistry - techniques and application to biodetection

    International Nuclear Information System (INIS)

    Khurshid, S.J.

    1993-01-01

    Microorganism isolated from specimens are usually identified by conventional bacterial identification procedures of morphological evaluation and cultural techniques. These complex methods of studying organisms are extremely tedious and time consuming. This causes serious problems by delaying the decision concerning the presence of pathogens and therefore the adequate drug therapy. Frequently, the decision about the presence of pathogens has to be made prior to the results of microbiological tests. In order to overcome these conditions, workers explored new instrumental methods for characterization, rapid acquisition, high reproducibility, computer aided data recording and interpretation of microorganisms. This article brief reviews application of these modern instrumental approaches such as Infrared Spectroscopy (IR), Gas Chromatography (GC), Fluorescence Spectroscopy, Bioluminescence, Chemiluminescence, FLow Cytometry, Micro calorimetry, GC-MASS Spectrometry, Electrical Impedance, Bio sensors and Radiometry. These techniques have increased the capacity of doing basic research with a major impact on both the clinical laboratories and industry. The radiometric procedure is being used for research and biological quality control of radiopharmaceuticals in our laboratory at PINSTECH. (author)

  18. A multi-modality concept for radiotherapy planning with imaging techniques

    International Nuclear Information System (INIS)

    Schultze, J.

    1993-01-01

    The reported multi-modality concept of radiotherapy planning in the LAN can be realised in any hospital with standard equipment, although in some cases by way of auxiliary configurations. A software is currently developed as a tool for reducing the entire planning work. The heart of any radiotherapy planning is the therapy simulator, which has to be abreast with the requirements of modern radiotherapy. Integration of tomograpy, digitalisation, and electronic data processing has added important modalities to therapy planning which allow more precise target volume definition, and better biophysical planning. This is what is needed in order to achieve well differentiated radiotherapy for treatment of the manifold tumors, and the quality standards expected by the supervisory quality assurance regime and the population. At present, the CT data still are transferred indirect, on storage media, to the EDP processing system of the radiotherapy planning system. Based on the tomographic slices given by the imaging data, the contours and technical problem solutions are derived automatically, either for multi-field radiotherapy or moving field irradiation, depending on the anatomy or the targets to be protected from ionizing radiation. (orig./VHE) [de

  19. SU-F-P-09: A Global Medical Physics Collaboration for Implementation of Modern Radiotherapy in Botswana

    International Nuclear Information System (INIS)

    Makufa, R; Bvochora-Nsingo, M; Karumekayi, T; Schneider, RJ; Efstathiou, JA; Gierga, DP; Dryden-Peterson, S; Odom, A; Shulman, A; Pipman, Y

    2016-01-01

    Purpose: The global burden of cancer is considerable, particularly in low and middle-income countries. Massachusetts General Hospital (MGH) and Botswana-Harvard AIDS Institute have partnered with the oncology community and government of Botswana to form BOTSOGO (BOTSwana Oncology Global Outreach) to address the rising burden of cancer in Botswana. Currently, radiation therapy (RT) is only available at a single linear accelerator (LINAC) in Gaborone Private Hospital (GPH). BOTSOGO worked to limit the absence of RT during a LINAC upgrade and ensure a safe transition to modern radiotherapy techniques. Methods: The existing Elekta Precise LINAC was decommissioned in November 2015 and replaced with a new Elekta VERSA-HD with IMRT/VMAT/CBCT capability. Upgraded treatment planning and record-and-verify systems were also installed. Physicists from GPH and MGH collaborated during an intensive on-site visit in Botswana during the commissioning process. Measurements were performed using newly purchased Sun Nuclear equipment. Photon beams were matched with an existing model to minimize the time needed for beam modeling and machine down time. Additional remote peer review was also employed. Independent dosimetry was performed by irradiating OSLDs, which were subsequently analyzed at MGH. Results: Photon beam quality agreed with reference data within 0.2%. Electron beam data agreed with example clinical data within 3%. Absolute dose calibration was performed using both IAEA and AAPM protocols. Absolute dose measurements with OSLDs agreed within 5%. Quentry cloud-based software was installed to facilitate remote review of treatment plans. Patient treatments resumed in February 2016. The time without RT was reduced, therefore likely resulting in reduced patient morbidity/mortality. Conclusion: A global physics collaboration was utilized to commission a modern LINAC in a resource-constrained setting. This can be a useful model in other areas with limited resources. Further use of

  20. SU-F-P-09: A Global Medical Physics Collaboration for Implementation of Modern Radiotherapy in Botswana

    Energy Technology Data Exchange (ETDEWEB)

    Makufa, R; Bvochora-Nsingo, M; Karumekayi, T [Gaborone Private Hospital, Gaborone (Botswana); Schneider, RJ [Massachusetts General Hospital, Boston, MA (United States); Efstathiou, JA; Gierga, DP [Massachusetts General Hospital, Boston, MA (United States); Harvard Medical School, Boston, MA (United States); Dryden-Peterson, S [Harvard Medical School, Boston, MA (United States); Brigham and Women’s Hospital, Boston, MA (United States); Odom, A [Associates in Medical Physics, Louisville, KY (United States); Shulman, A [Hamad Medical Corporation, Shelbyville, TN (United States); Pipman, Y [Forest Hills, NY (United States)

    2016-06-15

    Purpose: The global burden of cancer is considerable, particularly in low and middle-income countries. Massachusetts General Hospital (MGH) and Botswana-Harvard AIDS Institute have partnered with the oncology community and government of Botswana to form BOTSOGO (BOTSwana Oncology Global Outreach) to address the rising burden of cancer in Botswana. Currently, radiation therapy (RT) is only available at a single linear accelerator (LINAC) in Gaborone Private Hospital (GPH). BOTSOGO worked to limit the absence of RT during a LINAC upgrade and ensure a safe transition to modern radiotherapy techniques. Methods: The existing Elekta Precise LINAC was decommissioned in November 2015 and replaced with a new Elekta VERSA-HD with IMRT/VMAT/CBCT capability. Upgraded treatment planning and record-and-verify systems were also installed. Physicists from GPH and MGH collaborated during an intensive on-site visit in Botswana during the commissioning process. Measurements were performed using newly purchased Sun Nuclear equipment. Photon beams were matched with an existing model to minimize the time needed for beam modeling and machine down time. Additional remote peer review was also employed. Independent dosimetry was performed by irradiating OSLDs, which were subsequently analyzed at MGH. Results: Photon beam quality agreed with reference data within 0.2%. Electron beam data agreed with example clinical data within 3%. Absolute dose calibration was performed using both IAEA and AAPM protocols. Absolute dose measurements with OSLDs agreed within 5%. Quentry cloud-based software was installed to facilitate remote review of treatment plans. Patient treatments resumed in February 2016. The time without RT was reduced, therefore likely resulting in reduced patient morbidity/mortality. Conclusion: A global physics collaboration was utilized to commission a modern LINAC in a resource-constrained setting. This can be a useful model in other areas with limited resources. Further use of

  1. Hippocampal-Sparing Whole-Brain Radiotherapy: A 'How-To' Technique Using Helical Tomotherapy and Linear Accelerator-Based Intensity-Modulated Radiotherapy

    International Nuclear Information System (INIS)

    Gondi, Vinai; Tolakanahalli, Ranjini; Mehta, Minesh P.; Tewatia, Dinesh; Rowley, Howard; Kuo, John S.; Khuntia, Deepak; Tome, Wolfgang A.

    2010-01-01

    Purpose: Sparing the hippocampus during cranial irradiation poses important technical challenges with respect to contouring and treatment planning. Herein we report our preliminary experience with whole-brain radiotherapy using hippocampal sparing for patients with brain metastases. Methods and Materials: Five anonymous patients previously treated with whole-brain radiotherapy with hippocampal sparing were reviewed. The hippocampus was contoured, and hippocampal avoidance regions were created using a 5-mm volumetric expansion around the hippocampus. Helical tomotherapy and linear accelerator (LINAC)-based intensity-modulated radiotherapy (IMRT) treatment plans were generated for a prescription dose of 30 Gy in 10 fractions. Results: On average, the hippocampal avoidance volume was 3.3 cm 3 , occupying 2.1% of the whole-brain planned target volume. Helical tomotherapy spared the hippocampus, with a median dose of 5.5 Gy and maximum dose of 12.8 Gy. LINAC-based IMRT spared the hippocampus, with a median dose of 7.8 Gy and maximum dose of 15.3 Gy. On a per-fraction basis, mean dose to the hippocampus (normalized to 2-Gy fractions) was reduced by 87% to 0.49 Gy 2 using helical tomotherapy and by 81% to 0.73 Gy 2 using LINAC-based IMRT. Target coverage and homogeneity was acceptable with both IMRT modalities, with differences largely attributed to more rapid dose fall-off with helical tomotherapy. Conclusion: Modern IMRT techniques allow for sparing of the hippocampus with acceptable target coverage and homogeneity. Based on compelling preclinical evidence, a Phase II cooperative group trial has been developed to test the postulated neurocognitive benefit.

  2. Radiotherapy of degenerative joint disorders. Indication, technique and clinical results

    International Nuclear Information System (INIS)

    Keilholz, L.; Sauer, R.; Seegenschmiedt, M.H.; Alfred-Krupp-Krankenhaus, Essen

    1998-01-01

    From 1984 to 1994, 85 patients with painful osteoarthritis were treated. The mean follow-up was 4 (1 to 10) years. Seventy-three patients (103 joints) were available for long-term analysis: 17 patients (27 joints) with omarthrosis, 19 (20 joints) with rhizarthrosis, 31 (49 joints) with osteoarthritis of the knee and 6 patients (7 joints) with osteoarthritis of the hip. All patients were intensively pretreated over long time. Mean symptom duration prior to radiotherapy was 4 (1 to 10) years. Orthovoltage or linac photons were applied using some technical modifications depending upon the joint. Two radiotherapy series (6 x 1 Gy, total dose: 12 Gy, 3 weekly fractions) were prescribed. The interval between the 2 series was 6 weeks. The subjective pain profil was assessed prior to and 6 months after radiotherapy and at last follow-up. Forty-six (63%) patients (64 joints) achieved a reduction of pain symptoms; 16 of those had a 'major pain relief' and 14 'complete pain relief'. Large joints - knee and hip - responded better (64% each) than the rhizarthrosis (53%). All pain categories and grades and their combined pain score were significantly reduced. The pain reduction was mostly pronounced for the symptom 'pain at rest'. The orthopedic score correlated well with the subjective response of the patients. The thumb score improved in 11 (57%) joints, the shoulder score of Constant and Murley in 16 (59%), the Japonese knee score of Sasaki et al. in 33 (67%), the hip score of Harris in 5 (71%) joints. Only 9 of 19 patients which were treated to avoid surgery, had to be operated, and 3 of those received a total arthroplasty of the hip or knee. In multivariate analysis for the endpoint 'complete' or 'major pain relief' only the criterion 'symptom duration ≥2 years prior to radiotherapy' was an independent negative prognostic parameter. (orig./MG) [de

  3. Characterization of pre-hispanic pigments by modern analytical techniques

    International Nuclear Information System (INIS)

    Ortega A, M.

    2003-01-01

    In this work, the study of mural painting pigments from two archaeological sites (The Great Temple in Mexico city and Cacaxtla) was performed to know their materials composition, identify their structural characteristics and properties by using modern analytical techniques. Blue, ochre, red and black pigments of Mexica culture (1325-1521 a.C. / late Post Classic period); blue, ochre, red, brown, pink, green and white of Olmeca- Xicalanca culture (700-900 a.C. / Epiclassic period) were studied. Data about materials used, technological evolution, mineralogical background, cultural interchange and origin was obtained. Environmental exposition of these paintings since their discovering has produced changes and damage on their materials. Therefore, stability of some pigments has been notorious, ''Maya Blue'' specially presents extraordinary resistance to diluted and concentrated acids and alkalis including boiling condition, acqua regia, solvents, oxidant and reducing agents, moderate heat and biocorrosi6n; for that reason its study was emphasized. ''Maya Blue'' pigment was synthesized in laboratory using the processes described by historic sources (with indigophera suffruticosa leaves and synthetic indigo) up to obtain a stable pigment including acqua regia action. Clay matrix sorbs nearly 0.4 weight percent of organic dye, which cover 79% of palygorskita surface area. (Author)

  4. Modern Radar Techniques for Geophysical Applications: Two Examples

    Science.gov (United States)

    Arokiasamy, B. J.; Bianchi, C.; Sciacca, U.; Tutone, G.; Zirizzotti, A.; Zuccheretti, E.

    2005-01-01

    The last decade of the evolution of radar was heavily influenced by the rapid increase in the information processing capabilities. Advances in solid state radio HF devices, digital technology, computing architectures and software offered the designers to develop very efficient radars. In designing modern radars the emphasis goes towards the simplification of the system hardware, reduction of overall power, which is compensated by coding and real time signal processing techniques. Radars are commonly employed in geophysical radio soundings like probing the ionosphere; stratosphere-mesosphere measurement, weather forecast, GPR and radio-glaciology etc. In the laboratorio di Geofisica Ambientale of the Istituto Nazionale di Geofisica e Vulcanologia (INGV), Rome, Italy, we developed two pulse compression radars. The first is a HF radar called AIS-INGV; Advanced Ionospheric Sounder designed both for the purpose of research and for routine service of the HF radio wave propagation forecast. The second is a VHF radar called GLACIORADAR, which will be substituting the high power envelope radar used by the Italian Glaciological group. This will be employed in studying the sub glacial structures of Antarctica, giving information about layering, the bed rock and sub glacial lakes if present. These are low power radars, which heavily rely on advanced hardware and powerful real time signal processing. Additional information is included in the original extended abstract.

  5. Degradation of glass artifacts: application of modern surface analytical techniques.

    Science.gov (United States)

    Melcher, Michael; Wiesinger, Rita; Schreiner, Manfred

    2010-06-15

    A detailed understanding of the stability of glasses toward liquid or atmospheric attack is of considerable importance for preserving numerous objects of our cultural heritage. Glasses produced in the ancient periods (Egyptian, Greek, or Roman glasses), as well as modern glass, can be classified as soda-lime-silica glasses. In contrast, potash was used as a flux in medieval Northern Europe for the production of window panes for churches and cathedrals. The particular chemical composition of these potash-lime-silica glasses (low in silica and rich in alkali and alkaline earth components), in combination with increased levels of acidifying gases (such as SO(2), CO(2), NO(x), or O(3)) and airborne particulate matter in today's urban or industrial atmospheres, has resulted in severe degradation of important cultural relics, particularly over the last century. Rapid developments in the fields of microelectronics and computer sciences, however, have contributed to the development of a variety of nondestructive, surface analytical techniques for the scientific investigation and material characterization of these unique and valuable objects. These methods include scanning electron microscopy in combination with energy- or wavelength-dispersive spectrometry (SEM/EDX or SEM/WDX), secondary ion mass spectrometry (SIMS), and atomic force microscopy (AFM). In this Account, we address glass analysis and weathering mechanisms, exploring the possibilities (and limitations) of modern analytical techniques. Corrosion by liquid substances is well investigated in the glass literature. In a tremendous number of case studies, the basic reaction between aqueous solutions and the glass surfaces was identified as an ion-exchange reaction between hydrogen-bearing species of the attacking liquid and the alkali and alkaline earth ions in the glass, causing a depletion of the latter in the outermost surface layers. Although mechanistic analogies to liquid corrosion are obvious, atmospheric

  6. Radiotherapy.

    Science.gov (United States)

    Krause, Sonja; Debus, Jürgen; Neuhof, Dirk

    2011-01-01

    Solitary plasmocytoma occurring in bone (solitary plasmocytoma of the bone, SBP) or in soft tissue (extramedullary plasmocytoma, EP) can be treated effectively and with little toxicity by local radiotherapy. Ten-year local control rates of up to 90% can be achieved. Patients with multiple myeloma often suffer from symptoms such as pain or neurological impairments that are amenable to palliative radiotherapy. In a palliative setting, short treatment schedules and lower radiation doses are used to reduce toxicity and duration of hospitalization. In future, low-dose total body irradiation (TBI) may play a role in a potentially curative regimen with nonmyeloablative conditioning followed by allogenic peripheral blood stem cell transplantation.

  7. [Technique of complex mammary irradiation: Mono-isocentric 3D conformational radiotherapy and helical tomotherapy].

    Science.gov (United States)

    Vandendorpe, B; Guilbert, P; Champagne, C; Antoni, T; Nguyen, T D; Gaillot-Petit, N; Servagi Vernat, S

    2017-12-01

    To evaluate the dosimetric contribution of helical tomotherapy for breast cancers compared with conformal radiotherapy in mono-isocentric technique. For 23 patients, the dosimetric results in mono-isocentric 3D conformational radiotherapy did not satisfy the constraints either of target volumes nor organs at risk. A prospective dosimetric comparison between mono-isocentric 3D conformational radiotherapy and helical tomotherapy was therefore carried out. The use of helical tomotherapy showed a benefit in these 23 patients, with either an improvement in the conformity index or homogeneity, but with an increase in low doses. Of the 23 patients, two had pectus excavatum, five had past thoracic irradiation and two required bilateral irradiation. The other 14 patients had a combination of morphology and/or indication of lymph node irradiation. For these patients, helical tomotherapy was therefore preferred to mono-isocentric 3D conformational radiotherapy. Tomotherapy appears to provide better homogeneity and tumour coverage. This technique of irradiation may be justified in the case of morphological situations such as pectus exavatum and in complex clinical situations. In other cases, conformal radiotherapy in mono-isocentric technique remains to be favoured. Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  8. Voluntary Breath-hold Technique for Reducing Heart Dose in Left Breast Radiotherapy

    Science.gov (United States)

    Bartlett, Frederick R.; Colgan, Ruth M.; Donovan, Ellen M.; Carr, Karen; Landeg, Steven; Clements, Nicola; McNair, Helen A.; Locke, Imogen; Evans, Philip M.; Haviland, Joanne S.; Yarnold, John R.; Kirby, Anna M.

    2014-01-01

    Breath-holding techniques reduce the amount of radiation received by cardiac structures during tangential-field left breast radiotherapy. With these techniques, patients hold their breath while radiotherapy is delivered, pushing the heart down and away from the radiotherapy field. Despite clear dosimetric benefits, these techniques are not yet in widespread use. One reason for this is that commercially available solutions require specialist equipment, necessitating not only significant capital investment, but often also incurring ongoing costs such as a need for daily disposable mouthpieces. The voluntary breath-hold technique described here does not require any additional specialist equipment. All breath-holding techniques require a surrogate to monitor breath-hold consistency and whether breath-hold is maintained. Voluntary breath-hold uses the distance moved by the anterior and lateral reference marks (tattoos) away from the treatment room lasers in breath-hold to monitor consistency at CT-planning and treatment setup. Light fields are then used to monitor breath-hold consistency prior to and during radiotherapy delivery. PMID:25046661

  9. Comparison of 3DCRT,VMAT and IMRT techniques in metastatic vertebra radiotherapy: A phantom Study

    Directory of Open Access Journals (Sweden)

    Gedik Sonay

    2017-01-01

    Full Text Available Vertebra metastases can be seen during the prognosis of cancer patients. Treatment ways of the metastasis are radiotherapy, chemotherapy and surgery. Three-dimensional conformal therapy (3D-CRT is widely used in the treatment of vertebra metastases. Also, Intensity Modulated Radiotherapy (IMRT and Volumetric Arc Therapy (VMAT are used too. The aim of this study is to examine the advantages and disadvantages of the different radiotherapy techniques. In the aspect of this goal, it is studied with a randophantom in Uludag University Medicine Faculty, Radiation Oncology Department. By using a computerized tomography image of the phantom, one 3DCRT plan, two VMAT and three IMRT plans for servical vertebra and three different 3DCRT plans, two VMAT and two IMRT plans for lomber vertebra are calculated. To calculate 3DCRT plans, CMS XiO Treatment System is used and to calculate VMAT and IMRT plans Monaco Treatment Planning System is used in the department. The study concludes with the dosimetric comparison of the treatment plans in the spect of critical organ doses, homogeneity and conformity index. As a result of this study, all critical organ doses are suitable for QUANTEC Dose Limit Report and critical organ doses depend on the techniques which used in radiotherapy. According to homogeneity and conformity indices, VMAT and IMRT plans are better than one in 3DCRT plans in servical and lomber vertebra radiotherapy plans.

  10. Increasing the reliability of ecological models using modern software engineering techniques

    Science.gov (United States)

    Robert M. Scheller; Brian R. Sturtevant; Eric J. Gustafson; Brendan C. Ward; David J. Mladenoff

    2009-01-01

    Modern software development techniques are largely unknown to ecologists. Typically, ecological models and other software tools are developed for limited research purposes, and additional capabilities are added later, usually in an ad hoc manner. Modern software engineering techniques can substantially increase scientific rigor and confidence in ecological models and...

  11. Radiotherapy

    International Nuclear Information System (INIS)

    Pistenma, D.A.

    1980-01-01

    The need for radiotherapy research is exemplified by the 100,000 cancer patients who will fail treatment locally and/or regionally annually for the next several years but who would benefit from better local treatment modalities. Theoretically, all of the areas of investigation discussed in this projection paper have the potential to significantly improve local-regional treatment of cancer by radiotherapy alone or in combination with other modalities. In many of the areas of investigation discussed in this paper encouraging results have been obtained in cellular and animal tumor studies and in limited studies in humans as well. In the not too distant future the number of patients who would benefit from better local control may increase by tens of thousands if developments in chemotherapy and/or immunotherapy provide a means to eradicate disseminated microscopic foci of cancer. Thus the efforts to improve local-regional control take on even greater significance

  12. Breast radiotherapy in the lateral decubitus position: A technique to prevent lung and heart irradiation

    International Nuclear Information System (INIS)

    Campana, Francois; Kirova, Youlia M.; Rosenwald, Jean-Claude; Dendale, Remi; Vilcoq, Jacques R.; Dreyfus, Helene; Fourquet, Alain

    2005-01-01

    Purpose: To present an original technique for breast radiotherapy, with the aim of limiting lung and heart irradiation, satisfying quality assurance criteria. Methods and Material: An original radiotherapy technique for breast irradiation has been developed at the Institute Curie in January 1996. It consists of isocentric breast irradiation in the lateral decubitus position (isocentric lateral decubitus [ILD]). This technique is indicated for voluminous or pendulous breasts needing breast irradiation only. Thin carbon fiber supports and special patient positioning devices have been developed especially for this technique. In vivo measurements were performed to check the dose distribution before the routine use of the technique. Results: ILD has been successfully implemented in routine practice, and 500 patients have been already treated. Breast radiotherapy is performed using a dose of 50 Gy at ICRU point in 25 fractions. ILD shows good homogeneity of the dose in breast treatment volume, treatment fields are perpendicular to the skin ensuring its protection, and extremely low dose is delivered to the underlying lung and heart. Conclusion: In cases of voluminous breasts or patients with a history of lung and heart disease, our technique provides several advantages over the conventional technique with opposing tangential fields. This technique improves the dose homogeneity according to the ICRU recommendations

  13. modern devices/techniques in the protection of transformers

    African Journals Online (AJOL)

    The development of modern power systems has resulted in the design of wide range of transformers with ... step down this 330KV voltage to 132KV and then to distribution level of 33KV, which is ..... effect of the loss of the transformer and the.

  14. Modern possibilities of radiotherapy in the complex and single treatment of panaris

    International Nuclear Information System (INIS)

    Kolipiliev, V.; Momchev, M.

    1979-01-01

    Results are reported of the treatment of 282 patients with different forms of panaris: 39 per cent received radiotherapy alone, in the remaining radiotherapy was combined with surgical management, antibiotics and local treatment. Two different radiotherapy schemes were attempted: 49% of the patients received rather high single (50-80 rad) and total (300-600 rad) doses in the local site at a regimen of superficial (100 kV, 4 mm Al) or deep (180-200 kV, 0.5-1 mm Cu) roentgentherapy, with size of field 4/4 cm or 4/6 cm and 30-40 cm distance. In the remaining 51% of patients radiotherapy was characterized by dynamic fractionation and longer duration of procedures with significantly lower single (30-40 rad) and total (160-320 rad) doses. In recent years the second scheme has been preferred and has gain wide acceptance. Irradiation dose and rate invariably conformed to the type of inflammatory process. Patients with panaritium paronychium and panaritium subcutaneum admitted for treatment in the first few days of development of the digital infection required only several procedures on alternate days to achieve complete cure in a week. In the event of pus collection, 1 or 2 irradiation procedures accelerated abscess formation; this was followed by surgical intervention with postoperative radiotherapy to hasten the granulation process. Treatment of bone-and-joint forms of panaris was complex with initially higher single doses, followed by lower ones, applied up to twice weekly. The following advantages of the method are pointed out: shortening of treatment, respectively of the disability period; easy to perform, painless and practically innocuous manipulation. Complete cure could not be achieved only in advanced, torpid cases. (A.B.)

  15. If additional shielding required for the linear accelerator room when modern treatment techniques are intensively used

    International Nuclear Information System (INIS)

    Miller, Albert V.; Atkocius, Vydmantas; Aleknavicius, Eduardas

    2001-01-01

    Full text: Introduction - When the new linear accelerator is to be installed in radiotherapy department the responsible personnel should perform necessary estimations and calculations of the protective barriers for the accelerator treatment room. These methods are described in details in literature. However, if modern treatment techniques are planned to be intensively used on this machine, additional concern rises regarding adequacy of these calculations. The new Saturne-43 linear accelerator with three photon energies of 8, 15 and 25 MV recently installed at our department was, planned to be used for conventional treatment techniques as well as for conformal and total body treatments. The method of conformal therapy generally employs more small fields per one treated patient than conventional techniques. It leads to the use of more linear accelerator monitor units for the average treatment. It was estimated that 'beam on' time of an accelerator to deliver the same dose to the tumor is up to 3 times more than for conventional methods. The total body technique contribute to the extra time on of an accelerator because of extended distance to the dose prescription point. Altogether intensive clinical use of these modern techniques will noticeably increase 'beam on' time of an accelerator and rise question regarding validity of the traditionally calculated shielding of the treatment room. Materials and methods - IAEA-TECDOC-1040 and NCRP Report No 49 suggest considering three main components incident on the protective barriers: direct radiation, scatter radiation and leakage radiation. The formulas for these components are similar and dose equivalent limits are proportional to the workload. For the conventional treatments workloads of direct, scattered and leakage radiation are equal and calculated by the division of total prescribed dose (for all treated per week patients) to the machine isocenter to average tissue maximum ratio. These workloads for conformal and TBI

  16. Modern Theory of Gratings Resonant Scattering: Analysis Techniques and Phenomena

    CERN Document Server

    Sirenko, Yuriy K

    2010-01-01

    Diffraction gratings are one of the most popular objects of analysis in electromagnetic theory. The requirements of applied optics and microwave engineering lead to many new problems and challenges for the theory of diffraction gratings, which force us to search for new methods and tools for their resolution. In Modern Theory of Gratings, the authors present results of the electromagnetic theory of diffraction gratings that will constitute the base of further development of this theory, which meet the challenges provided by modern requirements of fundamental and applied science. This volume covers: spectral theory of gratings (Chapter 1) giving reliable grounds for physical analysis of space-frequency and space-time transformations of the electromagnetic field in open periodic resonators and waveguides; authentic analytic regularization procedures (Chapter 2) that, in contradistinction to the traditional frequency-domain approaches, fit perfectly for the analysis of resonant wave scattering processes; paramet...

  17. Inside out: modern imaging techniques to reveal animal anatomy.

    OpenAIRE

    Henrik Lauridsen; Kasper Hansen; Tobias Wang; Peter Agger; Jonas L Andersen; Peter S Knudsen; Anne S Rasmussen; Lars Uhrenholt; Michael Pedersen

    2011-01-01

    Animal anatomy has traditionally relied on detailed dissections to produce anatomical illustrations, but modern imaging modalities, such as MRI and CT, now represent an enormous resource that allows for fast non-invasive visualizations of animal anatomy in living animals. These modalities also allow for creation of three-dimensional representations that can be of considerable value in the dissemination of anatomical studies. In this methodological review, we present our experiences using MRI,...

  18. [Inheritance and evolution of acupuncture manipulation techniques of Zhejiang acupuncture masters in modern times].

    Science.gov (United States)

    Yu, Daxiong; Ma, Ruijie; Fang, Jianqiao

    2015-05-01

    There are many eminent acupuncture masters in modern times in the regions of Zhejiang province, which has developed the acupuncture schools of numerous characteristics and induces the important impacts at home and abroad. Through the literature collection on the acupuncture schools in Zhejiang and the interviews to the parties involved, it has been discovered that the acupuncture manipulation techniques of acupuncture masters in modern times are specifically featured. Those techniques are developed on the basis of Neijing (Internal Classic), Jinzhenfu (Ode to Gold Needle) and Zhenjiu Dacheng (Great Compendium of Acupuncture and Moxibustion). No matter to obey the old maxim or study by himself, every master lays the emphasis on the research and interpretation of classical theories and integrates the traditional with the modern. In the paper, the acupuncture manipulation techniques of Zhejiang acupuncture masters in modern times are stated from four aspects, named needling techniques in Internal Classic, feijingzouqi needling technique, penetrating needling technique and innovation of acupuncture manipulation.

  19. Hippocampal sparing radiotherapy for pediatric medulloblastoma: impact of treatment margins and treatment technique.

    Science.gov (United States)

    Brodin, N Patrik; Munck af Rosenschöld, Per; Blomstrand, Malin; Kiil-Berthlesen, Anne; Hollensen, Christian; Vogelius, Ivan R; Lannering, Birgitta; Bentzen, Søren M; Björk-Eriksson, Thomas

    2014-04-01

    We investigated how varying the treatment margin and applying hippocampal sparing and proton therapy impact the risk of neurocognitive impairment in pediatric medulloblastoma patients compared with current standard 3D conformal radiotherapy. We included 17 pediatric medulloblastoma patients to represent the variability in tumor location relative to the hippocampal region. Treatment plans were generated using 3D conformal radiotherapy, hippocampal sparing intensity-modulated radiotherapy, and spot-scanned proton therapy, using 3 different treatment margins for the conformal tumor boost. Neurocognitive impairment risk was estimated based on dose-response models from pediatric CNS malignancy survivors and compared among different margins and treatment techniques. Mean hippocampal dose and corresponding risk of cognitive impairment were decreased with decreasing treatment margins (P < .05). The largest risk reduction, however, was seen when applying hippocampal sparing proton therapy-the estimated risk of impaired task efficiency (95% confidence interval) was 92% (66%-98%), 81% (51%-95%), and 50% (30%-70%) for 3D conformal radiotherapy, intensity-modulated radiotherapy, and proton therapy, respectively, for the smallest boost margin and 98% (78%-100%), 90% (60%-98%), and 70% (39%-90%) if boosting the whole posterior fossa. Also, the distance between the closest point of the planning target volume and the center of the hippocampus can be used to predict mean hippocampal dose for a given treatment technique. We estimate a considerable clinical benefit of hippocampal sparing radiotherapy. In choosing treatment margins, the tradeoff between margin size and risk of neurocognitive impairment quantified here should be considered.

  20. Dosimetric study of volumetric arc modulation with RapidArc and intensity-modulated radiotherapy in patients with cervical cancer and comparison with 3-dimensional conformal technique for definitive radiotherapy in patients with cervical cancer

    Energy Technology Data Exchange (ETDEWEB)

    Guy, Jean-Baptiste [Department of Radiation Oncology, Institut de Cancérologie de la Loire Lucien Neuwirth, Saint-Priest en Jarez (France); Falk, Alexander T. [Department of Radiation Oncology, Centre Antoine Lacassagne, Nice (France); Auberdiac, Pierre [Department of Radiation Oncology, Clinique Claude Bernard, Albi (France); Cartier, Lysian; Vallard, Alexis [Department of Radiation Oncology, Institut de Cancérologie de la Loire Lucien Neuwirth, Saint-Priest en Jarez (France); Ollier, Edouard [Department of Pharmacology-Toxicology, Centre Hospitalier Universitaire de Saint-Etienne, Saint-Priest en Jarez (France); Trone, Jane-Chloé; Khodri, Moustapha [Department of Radiation Oncology, Institut de Cancérologie de la Loire Lucien Neuwirth, Saint-Priest en Jarez (France); Chargari, Cyrus [Department of Radiation Oncology, Hôpital d’instruction de Armées du Val-de-Grâce, Paris (France); Magné, Nicolas, E-mail: nicolas.magne@icloire.fr [Department of Radiation Oncology, Institut de Cancérologie de la Loire Lucien Neuwirth, Saint-Priest en Jarez (France)

    2016-04-01

    Introduction: For patients with cervical cancer, intensity-modulated radiation therapy (IMRT) improves target coverage and allows dose escalation while reducing the radiation dose to organs at risk (OARs). In this study, we compared dosimetric parameters among 3-dimensional conformal radiotherapy (3D-CRT), “step-and-shoot” IMRT, and volumetric intensity-modulated arc radiotherapy (VMAT) in a series of patients with cervical cancer receiving definitive radiotherapy. Computed tomography (CT) scans of 10 patients with histologically proven cervical cancer treated with definitive radiation therapy (RT) from December 2008 to March 2010 at our department were selected for this study. The gross tumor volume (GTV) and clinical target volume (CTV) were delineated following the guidelines of the Gyn IMRT consortium that included cervix, uterus, parametrial tissues, and the pelvic nodes including presacral. The median age was 57 years (range: 30 to 85 years). All 10 patients had squamous cell carcinoma with Federation of Gynecology and Obstetrics (FIGO) stage IB-IIIB. All patients were treated by VMAT. OAR doses were significantly reduced for plans with intensity-modulated technique compared with 3D-CRT except for the dose to the vagina. Between the 2 intensity-modulated techniques, significant difference was observed for the mean dose to the small intestine, to the benefit of VMAT (p < 0.001). There was no improvement in terms of OARs sparing for VMAT although there was a tendency for a slightly decreased average dose to the rectum: − 0.65 Gy but not significant (p = 0.07). The intensity modulation techniques have many advantages in terms of quality indexes, and particularly OAR sparing, compared with 3D-CRT. Following the ongoing technologic developments in modern radiotherapy, it is essential to evaluate the intensity-modulated techniques on prospective studies of a larger scale.

  1. Methodology of shooting training using modern IT techniques

    Science.gov (United States)

    Gudzbeler, Grzegorz; Struniawski, Jarosław

    2017-08-01

    Mastering, improvement, shaping and preservation of skills of safe, efficient and effective use of the firearm requires the use of relevant methodology of conducting the shooting training. However reality of police trainings does not usually allow for intensive training shooting with the use of ammunition. An alternative solution is the use of modern training technologies. Example of this is the "Virtual system of improvement tactics of intervention services responsible for security and shooting training." Introduction of stimulator to police trainings will enable complete stuff preparation to achieve its tasks, creating potential of knowledge and experience in many areas, far exceeding the capabilities of conventional training.

  2. Modern EMC analysis techniques II models and applications

    CERN Document Server

    Kantartzis, Nikolaos V

    2008-01-01

    The objective of this two-volume book is the systematic and comprehensive description of the most competitive time-domain computational methods for the efficient modeling and accurate solution of modern real-world EMC problems. Intended to be self-contained, it performs a detailed presentation of all well-known algorithms, elucidating on their merits or weaknesses, and accompanies the theoretical content with a variety of applications. Outlining the present volume, numerical investigations delve into printed circuit boards, monolithic microwave integrated circuits, radio frequency microelectro

  3. The new advances in radiotherapy technique challenges of quality assurance

    International Nuclear Information System (INIS)

    Hegazy, M.; Lecturer of Medical Physics Cairo University, Egypt

    2010-01-01

    What is Quality Assurance (QA)? This is all those planned and systematic actions necessary to provide confidence that a product or service will satisfy given requirements for quality. ISO 9000. It is the overall process which is supported by quality control activities. While, quality control describes the actual mechanisms and procedures by which one can assure quality. Consequences for radiotherapy A good acceptance testing and commissioning program is fundamental for any QA activities QA applies to both physical and clinical aspects of the treatment Treatment records must be kept of all relevant aspects of the treatment - including -Session and Summary Record information -Records all treatment parameters -Dose Calculations -Dose Measurements Particular emphasis is placed on QA of dosimetry A QA system itself and its outcomes must be critically reviewed. External audits are recommended to verify that the checks are not only done but that they also achieve what they are supposed to do Every good system requires an independent look at times A Comprehensive QA Program typically comprises Quality Assurance Committee, Policies and Procedures Manual, Quality Assurance team, Quality audit, Resources Introduction,..OBI in general. The On-Board Imager system is designed to correct for motion and setup errors of patients undergoing radiation therapy. It provides three imaging modes: Two-dimensional 2-D radiographic acquisition, Fluoroscopic image acquisition, and Three-dimensional 3-D cone-beam computed tomography CBCT acquisition. The fluoroscopic images are used to verify the gating thresholds of the respiratory gating system to account for intra-fraction i.e. respiratory motion. The radiographic images manage inter-fractional motion and setup errors. Using the 2D2DMatch and 3D3DMatch analysis tools a user can register the acquired kV or CBCT images with their associated reference image like DRR or planning CT for CBCT. Couch corrections are then downloaded to the linear

  4. Transformer ageing modern condition monitoring techniques and their interpretations

    CERN Document Server

    Purkait, Prithwiraj

    2017-01-01

    This book is a one-stop guide to state-of-the-art research in transformer ageing, condition monitoring and diagnosis. It is backed by rigorous research projects supported by the Australian Research Council in collaboration with several transmission and distribution companies. Many of the diagnostic techniques and tools developed in these projects have been applied by electricity utilities and would appeal to both researchers and practicing engineers. Important topics covered in this book include transformer insulation materials and their ageing behaviour, transformer condition monitoring techniques and detailed diagnostic techniques and their interpretation schemes. It also features a monitoring framework for smart transformers as well as a chapter on biodegradable oil.

  5. Power system stabilizers based on modern control techniques

    Energy Technology Data Exchange (ETDEWEB)

    Malik, O P; Chen, G P; Zhang, Y; El-Metwally, K [Calgary Univ., AB (Canada). Dept. of Electrical and Computer Engineering

    1994-12-31

    Developments in digital technology have made it feasible to develop and implement improved controllers based on sophisticated control techniques. Power system stabilizers based on adaptive control, fuzzy logic and artificial networks are being developed. Each of these control techniques possesses unique features and strengths. In this paper, the relative performance of power systems stabilizers based on adaptive control, fuzzy logic and neural network, both in simulation studies and real time tests on a physical model of a power system, is presented and compared to that of a fixed parameter conventional power system stabilizer. (author) 16 refs., 45 figs., 3 tabs.

  6. The effect on esophagus after different radiotherapy techniques for early stage Hodgkin's lymphoma

    DEFF Research Database (Denmark)

    Jørgensen, Anni; Maraldo, M.; Brodin, Nils Patrik

    2013-01-01

    The cure rate of early stage Hodgkin's lymphoma (HL) is excellent; investigating the late effects of treatment is thus important. Esophageal toxicity is a known side effect in patients receiving radiotherapy (RT) to the mediastinum, although little is known of this in HL survivors. This study inv...... investigates the dose to the esophagus in the treatment of early stage HL using different RT techniques. Estimated risks of early esophagitis, esophageal stricture and cancer are compared between treatments....

  7. Modern techniques in galaxy kinematics : Results from planetary nebula spectroscopy

    NARCIS (Netherlands)

    Romanowsky, AJ; Douglas, NG; Kuijken, K; Arnaboldi, M; Gerssen, J; Merrifield, MR; Kwok, S; Dopita, M; Sutherland, R

    2003-01-01

    We have observed planetary nebulae (PNe) in several early-type galaxies using new techniques on 4- to 8-meter-class telescopes. We obtain the first large data sets (greater than or similar to 100 velocities each) of PN kinematics in galaxies at greater than or similar to 15 Mpc, and present some

  8. Selected methods of waste monitoring using modern analytical techniques

    International Nuclear Information System (INIS)

    Hlavacek, I.; Hlavackova, I.

    1993-11-01

    Issues of the inspection and control of bituminized and cemented waste are discussed, and some methods of their nondestructive testing are described. Attention is paid to the inspection techniques, non-nuclear spectral techniques in particular, as employed for quality control of the wastes, waste concentrates, spent waste leaching solutions, as well as for the examination of environmental samples (waters and soils) from the surroundings of nuclear power plants. Some leaching tests used abroad for this purpose and practical analyses by the ICP-AES technique are given by way of example. The ICP-MS technique, which is unavailable in the Czech Republic, is routinely employed abroad for alpha nuclide measurements; examples of such analyses are also given. The next topic discussed includes the monitoring of organic acids and complexants to determine the degree of their thermal decomposition during the bituminization of wastes on an industrial line. All of the methods and procedures highlighted can be used as technical support during the monitoring of radioactive waste properties in industrial conditions, in the chemical and radiochemical analyses of wastes and related matter, in the calibration of nondestructive testing instrumentation, in the monitoring of contamination of the surroundings of nuclear facilities, and in trace analysis. (author). 10 tabs., 1 fig., 14 refs

  9. Pastoral Techniques in the Modern Danish Educational System

    Science.gov (United States)

    Nielsen, Klaus; Dalgaard, Susanne; Madsen, Sarah

    2011-01-01

    In recent years, therapeutic techniques have played an increasingly significant role in Danish educational thinking. One way in which this therapeutic thinking discloses itself is in the ever-growing use of educational-therapeutic games as part of the educational practice. Inspired by Foucault, we argue that educational-therapeutic games can be…

  10. Multicentre dosimetric comparison of photon-junctioning techniques in head and neck radiotherapy

    International Nuclear Information System (INIS)

    Kron, T.

    2003-01-01

    Because many head and neck radiotherapy treatment techniques rely on a junction between X-ray fields, it was the aim of the present study to investigate the use of different junctioning techniques and the affect on the dose across the junction. Techniques in use at nine radiotherapy centres in Australia were investigated using thermoluminescence dosimetry (TLD). The techniques could broadly be divided into two groups: (i) use of the light field to match the fields after moving the patient; and (ii) use of asymmetric collimation to create a single isocentre located in the junction. The mean dose at the junction and its reproducibility was studied in five consecutive treatments in each centre using 25 TLD chips placed throughout the junction in an anthropomorphic phantom. There was a tendency for the mono-isocentric technique to deliver a lower, more accurate mean dose at the junction (Group I: 1.22 Gy (n = 8) vs Group II: 0.96 Gy (n = 5) for 1 Gy planned, some centres contributed to both technique) with greater reproducibility (Group I: 9.6%, Group II: 5.1 % of the mean dose). We conclude that a mono-isocentric treatment technique has the potential to deliver a more accurate and reproducible dose distribution at the field junction of photon beams in head and neck treatment. Copyright (2003) Blackwell Science Pty Ltd

  11. Modernized Techniques for Dealing with Quality Data and Derived Products

    Science.gov (United States)

    Neiswender, C.; Miller, S. P.; Clark, D.

    2008-12-01

    "I just want a picture of the ocean floor in this area" is expressed all too often by researchers, educators, and students in the marine geosciences. As more sophisticated systems are developed to handle data collection and processing, the demand for quality data, and standardized products continues to grow. Data management is an invisible bridge between science and researchers/educators. The SIOExplorer digital library presents more than 50 years of ocean-going research. Prior to publication, all data is checked for quality using standardized criterion developed for each data stream. Despite the evolution of data formats and processing systems, SIOExplorer continues to present derived products in well- established formats. Standardized products are published for each cruise, and include a cruise report, MGD77 merged data, multi-beam flipbook, and underway profiles. Creation of these products is made possible by processing scripts, which continue to change with ever-evolving data formats. We continue to explore the potential of database-enabled creation of standardized products, such as the metadata-rich MGD77 header file. Database-enabled, automated processing produces standards-compliant metadata for each data and derived product. Metadata facilitates discovery and interpretation of published products. This descriptive information is stored both in an ASCII file, and a searchable digital library database. SIOExplorer's underlying technology allows focused search and retrieval of data and products. For example, users can initiate a search of only multi-beam data, which includes data-specific parameters. This customization is made possible with a synthesis of database, XML, and PHP technology. The combination of standardized products and digital library technology puts quality data and derived products in the hands of scientists. Interoperable systems enable distribution these published resources using technology such as web services. By developing modernized

  12. Possibilities and problems of modern dosimetry techniques in dentistry

    International Nuclear Information System (INIS)

    Regulla, D.F.

    Basic requirement for an optimized application of radiation in dentistry is a qualified dosimetry. The paper introduces into new dosimetry techniques based on solid state phenomena, such as luminescence an exoelectron emission, which, in case of dentistry, appear superior to conventional methods such as film and ionization chamber dosimetry. Advantages of the TLDs dosimeters, such as miniature detector volume, dynamic detection range, tissue equivalence etc., and their dosimetric possibilities are described together with hints on operational problems with respect to achieving high dosimetric measurement accuracy. (orig.) [de

  13. Modern techniques of explosive power in foothall-footballers

    Directory of Open Access Journals (Sweden)

    Bezyazichny B.I.

    2011-12-01

    Full Text Available The influence of plyometric training techniques in the process of athletes. The experiment involved 28 athletes (age 17-19 years. The duration of the experiment is 12 weeks. It is shown that for the gradual development of motor qualities necessary to implement integrated training. In training must be connected anaerobic and aerobic modes of loading. It is recommended that athletes training exercises include jump systems with vertical and horizontal overcoming obstacles, jumps into the depths. In one lesson, it is recommended to perform a series of 3.4 with a three-minute rest interval.

  14. Modern disposal techniques for sewage sludge and municipal waste; Moderne Entsorgungsverfahren fuer Klaerschlamm und Hausmuell

    Energy Technology Data Exchange (ETDEWEB)

    Garlipp, G. [Lurgi Energie und Umwelt GmbH, Frankfurt am Main (Germany); Maczek, K. [Lurgi Energie und Umwelt GmbH, Frankfurt am Main (Germany); Steinkamp, H. [Lurgi Energie und Umwelt GmbH, Frankfurt am Main (Germany)

    1996-05-01

    Since the passing of the technical code on municipal waste, the issue of the disposal of sewage sludge and municipal waste has become more and more important in Germany. Increasingly, the possibility is made use of to burn industrial and municipal sewage sludge and municipal waste. For such thermal disposal, a great number of techniques are nowadays available. (orig.) [Deutsch] Seit der Verabschiedung der TA Siedlungsabfall gewinnt die Problematik der Entsorgung von Klaerschlamm und Hausmuell in Deutschland zunehmend an Bedeutung. Von der Moeglichkeit, industrielle und kommunale Klaerschlaemme und Hausmuell zu verbrennen, wird in zunehmendem Masse Gebrauch gemacht. Zur thermischen Entsorgung von Klaerschlaemmen und Hausmuell stehen heute eine Vielzahl von Verfahren zur Verfuegung. (orig.)

  15. Modern machine learning techniques and their applications in cartoon animation research

    CERN Document Server

    Yu, Jun

    2013-01-01

    The integration of machine learning techniques and cartoon animation research is fast becoming a hot topic. This book helps readers learn the latest machine learning techniques, including patch alignment framework; spectral clustering, graph cuts, and convex relaxation; ensemble manifold learning; multiple kernel learning; multiview subspace learning; and multiview distance metric learning. It then presents the applications of these modern machine learning techniques in cartoon animation research. With these techniques, users can efficiently utilize the cartoon materials to generate animations

  16. ANALYSIS OF ANDROID VULNERABILITIES AND MODERN EXPLOITATION TECHNIQUES

    Directory of Open Access Journals (Sweden)

    Himanshu Shewale

    2014-03-01

    Full Text Available Android is an operating system based on the Linux kernel. It is the most widely used and popular operating system among Smartphones and portable devices. Its programmable and open nature attracts attackers to take undue advantage. Android platform allows developers to freely access and modify source code. But at the same time it increases the security issue. A user is likely to download and install malicious applications written by software hackers. This paper focuses on understanding and analyzing the vulnerabilities present in android platform. In this paper firstly we study the android architecture; analyze the existing threats and security weaknesses. Then we identify various exploit mitigation techniques to mitigate known vulnerabilities. A detailed analysis will help us to identify the existing loopholes and it will give strategic direction to make android operating system more secure.

  17. [Positioning errors of CT common rail technique in intensity-modulated radiotherapy for nasopharyngeal carcinoma].

    Science.gov (United States)

    Tian, Fei; Xu, Zihai; Mo, Li; Zhu, Chaohua; Chen, Chaomin

    2012-11-01

    To evaluate the value of CT common rail technique for application in intensity-modulated radiotherapy for nasopharyngeal carcinoma (NPC). Twenty-seven NPC patients underwent Somatom CT scans using the Siemens CTVision system prior to the commencement of the radiotherapy sessions. The acquired CT images were registered with the planning CT images using the matching function of the system to obtain the linear set-up errors of 3 directions, namely X (left to right), Y (superior to inferior), and Z (anterior to posterior). The errors were then corrected online on the moving couch. The 27 NPC patients underwent a total of 110 CT scans and the displacement deviations of the X, Y and Z directions were -0.16∓1.68 mm, 0.25∓1.66 mm, and 0.33∓1.09 mm, respectively. CT common rail technique can accurately and rapidly measure the space error between the posture and the target area to improve the set-up precision of intensity-modulated radiotherapy for NPC.

  18. Optimization of Stereotactic Radiotherapy Treatment Delivery Technique for Base-Of-Skull Meningiomas

    International Nuclear Information System (INIS)

    Clark, Brenda G.; Candish, Charles; Vollans, Emily; Gete, Ermias; Lee, Richard; Martin, Monty; Ma, Roy; McKenzie, Michael

    2008-01-01

    This study compares static conformal field (CF), intensity modulated radiotherapy (IMRT), and dynamic arcs (DA) for the stereotactic radiotherapy of base-of-skull meningiomas. Twenty-one cases of base-of-skull meningioma (median planning target volume [PTV] = 21.3 cm 3 ) previously treated with stereotactic radiotherapy were replanned with each technique. The plans were compared for Radiation Therapy Oncology Group conformity index (CI) and homogeneity index (HI), and doses to normal structures at 6 dose values from 50.4 Gy to 5.6 Gy. The mean CI was 1.75 (CF), 1.75 (DA), and 1.66 (IMRT) (p 3 , the CI (IMRT) was always superior to CI (DA) and CI (CF). At PTV sizes below 25 cm 3 , there was no significant difference in CI between each technique. There was no significant difference in HI between plans. The total volume of normal tissue receiving 50.4, 44.8, and 5.6 Gy was significantly lower when comparing IMRT to CF and DA plans (p 3 , due to improved conformity and normal tissue sparing, in particular for the brain stem and ipsilateral temporal lobe

  19. FXG dosimeter response for three-dimensional conformal radiotherapy using different evaluation techniques

    International Nuclear Information System (INIS)

    Cavinato, Christianne C.; Campos, Leticia L.; Souza, Benedito H.; Carrete Junior, Henrique; Daros, Kellen A.C.; Medeiros, Regina B.; Giordani, Adelmo J.

    2011-01-01

    This work aims to compare the dose-response of the Fricke xylenol gel (FXG) dosimeter developed at IPEN using 270 Bloom gelatin from porcine skin made in Brazil evaluated using the magnetic resonance imaging (MRI) technique with the dosimetric response evaluated using the optical absorption (OA) spectrophotometry technique, in order to verify the possibility of quality assurance (QA) and reproducibility of FXG dosimeter to be carried out routinely using the OA technique for three-dimensional conformal radiotherapy (3DCRT) application using a 6 MV photons linear accelerator. The response in function of the absorbed dose of FXG dosimeter developed at IPEN presents linear behavior in clinical interest dose range when irradiated with Co-60 gamma radiation and 6 MV photons and evaluated using the MRI and OA techniques. The results indicate that the optical technique can be used for QA of FXG dosemeter when used in the possible application in QA of 3DCRT. (author)

  20. FXG dosimeter response for three-dimensional conformal radiotherapy using different evaluation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Cavinato, Christianne C.; Campos, Leticia L., E-mail: ccavinato@ipen.b, E-mail: lcrodri@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Souza, Benedito H.; Carrete Junior, Henrique; Daros, Kellen A.C.; Medeiros, Regina B., E-mail: bhsouza@unifesp.b, E-mail: daros.kellen@unifesp.b, E-mail: rbitel-li.ddi@epm.b [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Dept. de Diagnostico por Imagem; Giordani, Adelmo J. [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Servico de Radioterapia

    2011-07-01

    This work aims to compare the dose-response of the Fricke xylenol gel (FXG) dosimeter developed at IPEN using 270 Bloom gelatin from porcine skin made in Brazil evaluated using the magnetic resonance imaging (MRI) technique with the dosimetric response evaluated using the optical absorption (OA) spectrophotometry technique, in order to verify the possibility of quality assurance (QA) and reproducibility of FXG dosimeter to be carried out routinely using the OA technique for three-dimensional conformal radiotherapy (3DCRT) application using a 6 MV photons linear accelerator. The response in function of the absorbed dose of FXG dosimeter developed at IPEN presents linear behavior in clinical interest dose range when irradiated with Co-60 gamma radiation and 6 MV photons and evaluated using the MRI and OA techniques. The results indicate that the optical technique can be used for QA of FXG dosemeter when used in the possible application in QA of 3DCRT. (author)

  1. Californium-252: isotope for modern radiotherapy of cervix, uterine and vaginal carcinomas

    International Nuclear Information System (INIS)

    Maruyama, J.; Beach, J.L.; Nagell, J.R. van

    1984-01-01

    Cf-252 is an isotope that can easily be afterloaded into available gynecological applicators and used for bulky cervix, uterus or vaginal cancer therapy. It is economical, time and cost effective in use, and can be applied to the therapy of many patients throughout the world. It is more effective for neutron therapy than machine fast neutron therapy and is the only form of neutron therapy producing consistent complication-free 5-year cure of advanced cancers currently available. Cf-252 is an isotope for modern gynecological tumor therapy for the future. Isodose curves for Cf-252 implants revealed dose distributions conforming well to tumor. (orig.) [de

  2. Modern integral equation techniques for quantum reactive scattering theory

    International Nuclear Information System (INIS)

    Auerbach, S.M.

    1993-11-01

    Rigorous calculations of cross sections and rate constants for elementary gas phase chemical reactions are performed for comparison with experiment, to ensure that our picture of the chemical reaction is complete. We focus on the H/D+H 2 → H 2 /DH + H reaction, and use the time independent integral equation technique in quantum reactive scattering theory. We examine the sensitivity of H+H 2 state resolved integral cross sections σ v'j',vj (E) for the transitions (v = 0,j = 0) to (v' = 1,j' = 1,3), to the difference between the Liu-Siegbahn-Truhlar-Horowitz (LSTH) and double many body expansion (DMBE) ab initio potential energy surfaces (PES). This sensitivity analysis is performed to determine the origin of a large discrepancy between experimental cross sections with sharply peaked energy dependence and theoretical ones with smooth energy dependence. We find that the LSTH and DMBE PESs give virtually identical cross sections, which lends credence to the theoretical energy dependence

  3. Modern

    Directory of Open Access Journals (Sweden)

    A.V. Bagrov

    2014-06-01

    Full Text Available The article gives an overview of the most important problems of modern meteoric astronomy and briefly describes ways and methods of their solutions. Particular attention is paid to the construction and arrangement of meteoric video cameras intended for registration of the meteoric phenomena as the main method of obtaining reliable and objective observational data on the basis of which the solution of the described tasks is possible.

  4. Paperless and paper-based processes in the modern radiotherapy department

    Energy Technology Data Exchange (ETDEWEB)

    Middleton, M. [Radiation Oncology Queensland, 280 North Street, Toowoomba 4350 (Australia)], E-mail: mark.middleton@roq.net.au; Bradford, C. [Harley St. Cancer Centre, London (United Kingdom); Frantzis, J. [Radiation Oncology Queensland, 280 North Street, Toowoomba 4350 (Australia); Ambler, A. [Harley St. Cancer Centre, London (United Kingdom); Sisson, T. [Radiation Oncology Queensland, 280 North Street, Toowoomba 4350 (Australia); Montgomerie, D. [Harley St. Cancer Centre, London (United Kingdom); Martin, J. [Radiation Oncology Queensland, 280 North Street, Toowoomba 4350 (Australia)

    2009-11-15

    Purpose: To assess the implications on workflow and efficiency in a paperless environment versus a traditional paper-based environment. This paper summarises the comparison of specific workflow practices conducted in a paperless and paper-based approach, comparing time taken, potential advantages and disadvantages of each approach, and the cost-effectiveness of a paperless approach. Methods and materials: A time study was undertaken on three specific workflow areas for 5 patients with breast and prostate cancer respectively, and comparison made between paperless and paper-based methodology. The workflow areas analysed were electronic treatment record (ETR) versus treatment sheet preparation, digital history check process versus paper-based and digital image and trend analysis versus paper-based. The cost-effectiveness of a paperless approach was then analysed. Additionally a staff questionnaire was undertaken, assessing Information Technology (IT) skills of staff and comfort levels pertaining to a paperless environment. Results: There was on average a 50% reduction in workload when comparing an ETR versus a paper-based treatment sheet, a 50% reduction in workload by utilising a paperless history check process and a 70% reduction in workload with a paperless image and trend analysis process. There was also significant cost savings by introducing a paperless workflow. The survey showed a higher level of comfort with information technology in the paperless environment, and less frustration with aspects of working in the paper-based centre. Conclusion: The digital radiotherapy department offers highly significant improvements in efficiency. These potentially translate into major financial savings and increased job satisfaction.

  5. Paperless and paper-based processes in the modern radiotherapy department

    International Nuclear Information System (INIS)

    Middleton, M.; Bradford, C.; Frantzis, J.; Ambler, A.; Sisson, T.; Montgomerie, D.; Martin, J.

    2009-01-01

    Purpose: To assess the implications on workflow and efficiency in a paperless environment versus a traditional paper-based environment. This paper summarises the comparison of specific workflow practices conducted in a paperless and paper-based approach, comparing time taken, potential advantages and disadvantages of each approach, and the cost-effectiveness of a paperless approach. Methods and materials: A time study was undertaken on three specific workflow areas for 5 patients with breast and prostate cancer respectively, and comparison made between paperless and paper-based methodology. The workflow areas analysed were electronic treatment record (ETR) versus treatment sheet preparation, digital history check process versus paper-based and digital image and trend analysis versus paper-based. The cost-effectiveness of a paperless approach was then analysed. Additionally a staff questionnaire was undertaken, assessing Information Technology (IT) skills of staff and comfort levels pertaining to a paperless environment. Results: There was on average a 50% reduction in workload when comparing an ETR versus a paper-based treatment sheet, a 50% reduction in workload by utilising a paperless history check process and a 70% reduction in workload with a paperless image and trend analysis process. There was also significant cost savings by introducing a paperless workflow. The survey showed a higher level of comfort with information technology in the paperless environment, and less frustration with aspects of working in the paper-based centre. Conclusion: The digital radiotherapy department offers highly significant improvements in efficiency. These potentially translate into major financial savings and increased job satisfaction.

  6. Application of Modern Experimental Technique to Solve Morphological Complexity in Plants Taxonomy

    Directory of Open Access Journals (Sweden)

    SURANTO

    2000-07-01

    Full Text Available Modern taxonomy has two approaches, i.e. classical and experimental taxonomy. Classical taxonomy uses morphological characters, while experimental taxonomy uses broader methods including chemistry, physics and mathematics, in the form of laboratory data that are revealed together with the progress of optical technique (microscope, chemistry methods (chromatography, electrophoresis, etc. Modern taxonomy tends to use series of interrelated data. More data used would result in more validity and give better clarification of taxonomic status. A lot of modern taxonomic data such as palynology, cytotaxonomy (cytology, chemical constituent (chemotaxonomy, isozyme and DNA sequencing were used recently.

  7. Optimum radiotherapy schedule for uterine cervical cancer based-on the detailed information of dose fractionation and radiotherapy technique

    International Nuclear Information System (INIS)

    Cho, Jae Ho; Kim, Hyun Chang; Suh, Chang Ok

    2005-01-01

    The best dose-fractionation regimen of the definitive radiotherapy for cervix cancer remains to be clearly determined. It seems to be partially attributed to the complexity of the affecting factors and the lack of detailed information on external and intra-cavitary fractionation. To find optimal practice guidelines, our experiences of the combination of external beam radiotherapy (EBRT) and high-dose-rate intracavitary brachytherapy (HDR-ICBT) were reviewed with detailed information of the various treatment parameters obtained from a large cohort of women treated homogeneously at a single institute. The subjects were 743 cervical cancer patients (Stage IB 198, IIA 77, IIB 364, IIIA 7, IIIB 89 and IVA 8) treated by radiotherapy alone, between 1990 and 1996. A total external beam radiotherapy (EBRT) dose of 23.4 ∼ 59.4 Gy (Median 45.0) was delivered to the whole pelvis. High-dose-rate intracavitary brachytherapy (HDR-ICBT) was also performed using various fractionation schemes. A Midline block (MLB) was initiated after the delivery of 14.4∼ 43.2 Gy (Median 36.0) of EBRT in 495 patients, while in the other 248 patients EBRT could not be used due to slow tumor regression or the huge initial bulk of tumor. The point A, actual bladder and rectal doses were individually assessed in all patients. The biologically effective dose (BED) to the tumor (α / β = 10) and late-responding tissues (α /β = 3) for both EBRT and HDR-ICBT were calculated. The total BED values to point A, the actual bladder and rectal reference points were the summation of the EBRT and HDR-ICBT. In addition to all the details on dose-fractionation, the other factors (i.e. the overall treatment time, physicians preference) that can affect the schedule of the definitive radiotherapy were also thoroughly analyzed. The association between MD-BED Gy 3 and the risk of complication was assessed using serial multiple logistic regressions models. The associations between R-BED Gy 3 and rectal complications

  8. A comparison of different three-dimensional treatment planning techniques for localized radiotherapy of prostate cancer

    International Nuclear Information System (INIS)

    Koswig, S.; Dinges, S.; Buchali, A.; Boehmer, D.; Salk, J.; Rosenthal, P.; Harder, C.; Schlenger, L.; Budach, V.

    1999-01-01

    Purpose: Four different three-dimensional planning techniques for localized radiotherapy of prostate cancer were compared with regard to dose homogeneity within the target volume and dose to organs at risk, dependent upon tumor stage. Patients and Methods: Six patients with stage T1, 7 patients with stage T2 and 4 patients with stage T3 were included in this study. Four different 3D treatment plans (rotation, 4-field, 5-field and 6-field technique) were calculated for each patient. Dose was calculated with the reference point at the isocenter (100%). The planning target volume was encompassed within the 95% isodose surface. All the techniques used different shaped portal for each beam. Dose volume histograms were created and compared for the planning target volume and the organs at risk (33%, 50%, 66% volume level) in all techniques. Results: The 4 different three-dimensional planning techniques revealed no differences concerning dose homogeneity within the planning target volume. The dose volume distribution at organs at risk show differences between the calculated techniques. In our study the best protection for bladder and rectum in stage T1 and T2 was achieved by the 6-field technique. A significant difference was achieved between 6-field and 4-field technique only in the 50% volume of the bladder (p=0.034), between the 6-field and rotation technique (all volume levels) and between 5-field and rotation technique (all volume levels). In stage T1, T2 6-field and 4-field technique in 50% (p-0.033) and 66% (p=0.011) of the rectum volume. In stage T3 a significant difference was not observed between the 4 techniques. The best protection of head of the femur was achieved by the rotation technique. Conclusion: In the localized radiotherapy of prostate cancer in stage T1 or T2 the best protection for bladder and rectum was achieved by a 3D-planned conformal 6-field technique. If the seminal vesicles have been included in the target volume and in the case of large

  9. Three-Dimensional Conformal Simultaneously Integrated Boost Technique for Breast-Conserving Radiotherapy

    International Nuclear Information System (INIS)

    Laan, Hans Paul van der; Dolsma, Wil V.; Maduro, John H.; Korevaar, Erik W.; Hollander, Miranda; Langendijk, Johannes A.

    2007-01-01

    Purpose: To compare the target coverage and normal tissue dose with the simultaneously integrated boost (SIB) and the sequential boost technique in breast cancer, and to evaluate the incidence of acute skin toxicity in patients treated with the SIB technique. Methods and Materials: Thirty patients with early-stage left-sided breast cancer underwent breast-conserving radiotherapy using the SIB technique. The breast and boost planning target volumes (PTVs) were treated simultaneously (i.e., for each fraction, the breast and boost PTVs received 1.81 Gy and 2.3 Gy, respectively). Three-dimensional conformal beams with wedges were shaped and weighted using forward planning. Dose-volume histograms of the PTVs and organs at risk with the SIB technique, 28 x (1.81 + 0.49 Gy), were compared with those for the sequential boost technique, 25 x 2 Gy + 8 x 2 Gy. Acute skin toxicity was evaluated for 90 patients treated with the SIB technique according to Common Terminology Criteria for Adverse Events, version 3.0. Results: PTV coverage was adequate with both techniques. With SIB, more efficiently shaped boost beams resulted in smaller irradiated volumes. The mean volume receiving ≥107% of the breast dose was reduced by 20%, the mean volume outside the boost PTV receiving ≥95% of the boost dose was reduced by 54%, and the mean heart and lung dose were reduced by 10%. Of the evaluated patients, 32.2% had Grade 2 or worse toxicity. Conclusion: The SIB technique is proposed for standard use in breast-conserving radiotherapy because of its dose-limiting capabilities, easy implementation, reduced number of treatment fractions, and relatively low incidence of acute skin toxicity

  10. Radiotherapy physics

    International Nuclear Information System (INIS)

    Chen, G.T.Y.; Collier, J.M.; Lyman, J.T.; Pitluck, S.

    1982-01-01

    The Radiotherapy Physics Group works on the physical and biophysical aspects of charged particle radiotherapy. Our activities include the development of isosurvival beams (beams of uniform biological effect), computerized treatment planning development for charged particle radiotherapy, design of compensation to shape dose distributions, and development of dosimetry techniques to verify planned irradiations in both phantoms and patients

  11. Use of Collage Technique in Modern Art Perceptions of Visual Arts Teacher Candidates: Action Research

    Directory of Open Access Journals (Sweden)

    Görkem Utku ALPARSLAN

    2018-01-01

    Full Text Available The purpose of the research is to demonstrate the contribution of the collage technique to modern art perceptions of visual arts teacher candidates. Research has been designed in the form of an action research from qualitative research methods. The study was conducted for eight weeks. The data of the study, the student journals and the pictures of the students before, during and after the application were collected and evaluated by rubric. In the study, it was found that students 'pictures of rubbing their images with rubbing techniques developed as a result of modern formal intellectual and formative reflection and as a result of the descriptive analysis of qualitative data, students' awareness of modern visual intellectual and formal foundations and collage technique increased. As a result of the research, the level of skill of expressing modern formal expression was observed in the students' work and it was determined that the awareness of students about the formal and intellectual structure of modern picture and collage technique increased in the frame of originality, criticism and creativity.

  12. Radiological techniques in X-ray diagnosis and radiotherapy. 2. enlarged ed.

    International Nuclear Information System (INIS)

    Koecher, E.; Kriester, A.

    1990-01-01

    Since this textbook's first edition appeared in 1981 (INIS:14(13):764471, EDB:83(15):134474), there has been sweeping change in the field of radiological techniques. This is evident from the refinements made to visualisation techniques already used in the past, the development of further methods of imaging and the important role increasingly assumed by innovative computerized procedures. In view of this fact, the relevant curricula and the textbook were thoroughly revised, to keep abreast of the most recent trends. As a result, the new version offers additional contributions on numerous subject groups like 'Transportable X-Ray Units', 'X-Ray Units for Stomatology', 'Fundamentals of Digital Technique' and 'Ultrasound Tomography' as well as sections dealing with quality assurance and electric safety measures. On the other hand, physical and methodological aspects of radiology and radiotherapy, which had been given ample coverage in the first edition, were deliberately neglected here. (orig./HP) With 136 figs., 20 tabs [de

  13. Markerless gating for lung cancer radiotherapy based on machine learning techniques

    International Nuclear Information System (INIS)

    Lin Tong; Li Ruijiang; Tang Xiaoli; Jiang, Steve B; Dy, Jennifer G

    2009-01-01

    In lung cancer radiotherapy, radiation to a mobile target can be delivered by respiratory gating, for which we need to know whether the target is inside or outside a predefined gating window at any time point during the treatment. This can be achieved by tracking one or more fiducial markers implanted inside or near the target, either fluoroscopically or electromagnetically. However, the clinical implementation of marker tracking is limited for lung cancer radiotherapy mainly due to the risk of pneumothorax. Therefore, gating without implanted fiducial markers is a promising clinical direction. We have developed several template-matching methods for fluoroscopic marker-less gating. Recently, we have modeled the gating problem as a binary pattern classification problem, in which principal component analysis (PCA) and support vector machine (SVM) are combined to perform the classification task. Following the same framework, we investigated different combinations of dimensionality reduction techniques (PCA and four nonlinear manifold learning methods) and two machine learning classification methods (artificial neural networks-ANN and SVM). Performance was evaluated on ten fluoroscopic image sequences of nine lung cancer patients. We found that among all combinations of dimensionality reduction techniques and classification methods, PCA combined with either ANN or SVM achieved a better performance than the other nonlinear manifold learning methods. ANN when combined with PCA achieves a better performance than SVM in terms of classification accuracy and recall rate, although the target coverage is similar for the two classification methods. Furthermore, the running time for both ANN and SVM with PCA is within tolerance for real-time applications. Overall, ANN combined with PCA is a better candidate than other combinations we investigated in this work for real-time gated radiotherapy.

  14. Pencilbeam irradiation technique for whole brain radiotherapy: technical and biological challenges in a small animal model.

    Science.gov (United States)

    Schültke, Elisabeth; Trippel, Michael; Bräuer-Krisch, Elke; Renier, Michel; Bartzsch, Stefan; Requardt, Herwig; Döbrössy, Máté D; Nikkhah, Guido

    2013-01-01

    We have conducted the first in-vivo experiments in pencilbeam irradiation, a new synchrotron radiation technique based on the principle of microbeam irradiation, a concept of spatially fractionated high-dose irradiation. In an animal model of adult C57 BL/6J mice we have determined technical and physiological limitations with the present technical setup of the technique. Fifty-eight animals were distributed in eleven experimental groups, ten groups receiving whole brain radiotherapy with arrays of 50 µm wide beams. We have tested peak doses ranging between 172 Gy and 2,298 Gy at 3 mm depth. Animals in five groups received whole brain radiotherapy with a center-to-center (ctc) distance of 200 µm and a peak-to-valley ratio (PVDR) of ∼ 100, in the other five groups the ctc was 400 µm (PVDR ∼ 400). Motor and memory abilities were assessed during a six months observation period following irradiation. The lower dose limit, determined by the technical equipment, was at 172 Gy. The LD50 was about 1,164 Gy for a ctc of 200 µm and higher than 2,298 Gy for a ctc of 400 µm. Age-dependent loss in motor and memory performance was seen in all groups. Better overall performance (close to that of healthy controls) was seen in the groups irradiated with a ctc of 400 µm.

  15. A mono isocentric radiotherapy technique for craniospinal irradiation using asymmetric jaws

    International Nuclear Information System (INIS)

    Isin, G; Oezyar, E.; Guerdalli, S.; Arslan, G.; Uzal, D.; Atahan, I. L.

    1995-01-01

    Dose distribution across the junction of matching of craniospinal fields (lateral cranial fields and posterior spinal field) is important as severe complications may result if the beams overlap or disease may recurs if the gapping is too conservative. Various techniques have been used to achieve an effective transverse plane match and half-beam block technique is one of these techniques. Here, we describe a mono isocentric technique for the treatment of craniospinal fields using the asymmetric jaws of our linear accelerator (Philips SL-25). Before the clinical application of this non-standard technique, basic dosimetry parameters are evaluated. Asymmetric collimator dose distributions for various asymmetric field sizes were obtained and compared with symmetric dose distributions for 6 MV x-ray. A computerized 3-D water phantom with a pair of ionization chambers (reference and field) was used for dose profiles, isodose distributions and Percentage Depth Dose (PDD) for various asymmetric field sizes and different off axis distances. The measured values of off axis ratios for the interested depths were used in MU calculations. This new mono isocentric technique provides an ideal dose distribution at match-line as there is no need to move the patient during treatment. Use of heavy secondary cerrobend blocks (beam splitters) is eliminated. This technique provides the ease of consequent daily set-up's and fulfills the requirements for a conformal radiotherapy

  16. Applications of Modern Analysis Techniques in Searching back Ancient Art Ceramic Technologies

    Directory of Open Access Journals (Sweden)

    Nguyen Quang Liem

    2011-12-01

    Full Text Available This report highlights the promising applications of modern analysis techniques such as Scanning Electron Microsopy, X-ray fluorescence, X-ray diffraction, Raman scattering spectroscopy, and thermal expansion measurement in searching back the ancient art ceramics technologies.

  17. Transfer of physics detector models into CAD systems using modern techniques

    International Nuclear Information System (INIS)

    Dach, M.; Vuoskoski, J.

    1996-01-01

    Designing high energy physics detectors for future experiments requires sophisticated computer aided design and simulation tools. In order to satisfy the future demands in this domain, modern techniques, methods, and standards have to be applied. We present an interface application, designed and implemented using object-oriented techniques, for the widely used GEANT physics simulation package. It converts GEANT detector models into the future industrial standard, STEP. (orig.)

  18. Speech Impact Realization via Manipulative Argumentation Techniques in Modern American Political Discourse

    OpenAIRE

    Zarine Avetisyan

    2015-01-01

    The present paper presents the discussion of scholars concerning speech impact, peculiarities of its realization, speech strategies and techniques in particular. Departing from the viewpoints of many prominent linguists, the paper suggests that manipulative argumentation be viewed as a most pervasive speech strategy with a certain set of techniques which are to be found in modern American political discourse. The precedence of their occurrence allows us to regard them as ...

  19. Application of metabonomic analytical techniques in the modernization and toxicology research of traditional Chinese medicine.

    Science.gov (United States)

    Lao, Yong-Min; Jiang, Jian-Guo; Yan, Lu

    2009-08-01

    In the recent years, a wide range of metabonomic analytical techniques are widely used in the modern research of traditional Chinese medicine (TCM). At the same time, the international community has attached increasing importance to TCM toxicity problems. Thus, many studies have been implemented to investigate the toxicity mechanisms of TCM. Among these studies, many metabonomic-based methods have been implemented to facilitate TCM toxicity investigation. At present, the most prevailing methods for TCM toxicity research are mainly single analysis techniques using only one analytical means. These techniques include nuclear magnetic resonance (NMR), gas chromatography-mass spectrometry (GC-MS), and liquid chromatography-mass spectrometry (LC-MS), etc.; with these techniques, some favourable outcomes have been gained in the toxic reaction studies of TCM, such as the action target organs assay, the establishment of action pattern, the elucidation of action mechanism and the exploration of action material foundation. However, every analytical technique has its advantages and drawbacks, no existing analytical technique can be versatile. Multi-analysed techniques can partially overcome the shortcomings of single-analysed techniques. Combination of GC-MS and LC-MS metabolic profiling approaches has unravelled the pathological outcomes of aristolochic acid-induced nephrotoxicity, which can not be achieved by single-analysed techniques. It is believed that with the further development of metabonomic analytical techniques, especially multi-analysed techniques, metabonomics will greatly promote TCM toxicity research and be beneficial to the modernization of TCM in terms of extending the application of modern means in the TCM safety assessment, assisting the formulation of TCM safety norms and establishing the international standards indicators.

  20. Conventional and conformal technique of external beam radiotherapy in locally advanced cervical cancer: Dose distribution, tumor response, and side effects

    Science.gov (United States)

    Mutrikah, N.; Winarno, H.; Amalia, T.; Djakaria, M.

    2017-08-01

    The objective of this study was to compare conventional and conformal techniques of external beam radiotherapy (EBRT) in terms of the dose distribution, tumor response, and side effects in the treatment of locally advanced cervical cancer patients. A retrospective cohort study was conducted on cervical cancer patients who underwent EBRT before brachytherapy in the Radiotherapy Department of Cipto Mangunkusumo Hospital. The prescribed dose distribution, tumor response, and acute side effects of EBRT using conventional and conformal techniques were investigated. In total, 51 patients who underwent EBRT using conventional techniques (25 cases using Cobalt-60 and 26 cases using a linear accelerator (LINAC)) and 29 patients who underwent EBRT using conformal techniques were included in the study. The distribution of the prescribed dose in the target had an impact on the patient’s final response to EBRT. The complete response rate of patients to conformal techniques was significantly greater (58%) than that of patients to conventional techniques (42%). No severe acute local side effects were seen in any of the patients (Radiation Therapy Oncology Group (RTOG) grades 3-4). The distribution of the dose and volume to the gastrointestinal tract affected the proportion of mild acute side effects (RTOG grades 1-2). The urinary bladder was significantly greater using conventional techniques (Cobalt-60/LINAC) than using conformal techniques at 72% and 78% compared to 28% and 22%, respectively. The use of conformal techniques in pelvic radiation therapy is suggested in radiotherapy centers with CT simulators and 3D Radiotherapy Treatment Planning Systems (RTPSs) to decrease some uncertainties in radiotherapy planning. The use of AP/PA pelvic radiation techniques with Cobalt-60 should be limited in body thicknesses equal to or less than 18 cm. When using conformal techniques, delineation should be applied in the small bowel, as it is considered a critical organ according to RTOG

  1. Efficient CT simulation of the four-field technique for conformal radiotherapy of prostate carcinoma

    International Nuclear Information System (INIS)

    Valicenti, Richard K.; Waterman, Frank M.; Croce, Raymond J.; Corn, Benjamin; Suntharalingam, Nagalingam; Curran, Walter J.

    1997-01-01

    Purpose: Conformal radiotherapy of prostate carcinoma relies on contouring of individual CT slices for target and normal tissue localization. This process can be very time consuming. In the present report, we describe a method to more efficiently localize pelvic anatomy directly from digital reconstructed radiographs (DRRs). Materials and Methods: Ten patients with prostate carcinoma underwent CT simulation (the spiral mode at 3 mm separation) for conformal four-field 'box' radiotherapy. The bulbous urethra and bladder were opacified with iodinated contrast media. On lateral and anteroposterior DRRs, the volume of interest (VOI) was restricted to 1.0-1.5 cm tissue thickness to optimize digital radiograph reconstruction of the prostate and seminal vesicles. By removing unessential voxel elements, this method provided direct visualization of those structures. For comparison, the targets of each patient were also obtained by contouring CT axial slices. Results: The method was successfully performed if the target structures were readily visualized and geometrically corresponded to those generated by contouring axial images. The targets in 9 of 10 patients were reliable representations of the CT-contoured volumes. One patient had 18 mm variation due to the lack of bladder opacification. Using VOIs to generate thin tissue DRRs, the time required for target and normal tissue localization was on the average less than 5 min. Conclusion: In CT simulation of the four-field irradiation technique for prostate carcinoma, thin-tissue DRRs allowed for efficient and accurate target localization without requiring individual axial image contouring. This method may facilitate positioning of the beam isocenter and provide reliable conformal radiotherapy

  2. Difference in temporal lobe dose between two radiotherapy techniques in the treatment of NPC with anterior nasal involvement

    International Nuclear Information System (INIS)

    Wu, V.W.C.; Luk, J.H.Y.; Wong, S.F.T.; Lam, E.C.H.; Fung, M.C.Y.; Tong, S.M.; Ku, I.K.M.

    1997-01-01

    Nasopharyngeal carcinoma with anterior extension are treated with special radiotherapy techniques. The purpose of this study is to investigate the difference of temporal lobe dose between two radiotherapy techniques (A and B) which are commonly used in the treatment of such condition in Hong Kong. The study is carried out by performing radiation treatments to a humanoid phantom under simulated conditions of the two techniques. The dose measurement is done by thermoluminescent dosimeters (TLD) which are placed inside the phantom. Both techniques employ a '3-field' arrangement: a heavy-weighted anterior facial fields with two lateral opposing facial fields. The main difference lies in the anterior facial field in which technique A uses electron beam throughout while technique B uses a mixture of photon and electron beams. The results demonstrates that technique A delivers higher dose to temporal lobe than technique B. In a course of radical external beam radiotherapy (66 Gy), the mean dose to inferior temporal lobe are 59.29 Gy in technique A and 34.06 Gy in technique B respectively (p < 0.0001). Furthermore, it is found that the temporal lobe dose difference between the two techniques is mainly due to their phase I treatment. (p < 0.0001 for phase I and p = 0.078 for phase II). (authors)

  3. Difference in temporal lobe dose between two radiotherapy techniques in the treatment of NPC with anterior nasal involvement

    Energy Technology Data Exchange (ETDEWEB)

    Wu, V.W.C.; Luk, J.H.Y.; Wong, S.F.T.; Lam, E.C.H.; Fung, M.C.Y.; Tong, S.M.; Ku, I.K.M. [Hong Kong Polytechnic University, Hong Kong, (Hong Kong). Department of Radiography and Optometry

    1997-04-01

    Nasopharyngeal carcinoma with anterior extension are treated with special radiotherapy techniques. The purpose of this study is to investigate the difference of temporal lobe dose between two radiotherapy techniques (A and B) which are commonly used in the treatment of such condition in Hong Kong. The study is carried out by performing radiation treatments to a humanoid phantom under simulated conditions of the two techniques. The dose measurement is done by thermoluminescent dosimeters (TLD) which are placed inside the phantom. Both techniques employ a `3-field` arrangement: a heavy-weighted anterior facial fields with two lateral opposing facial fields. The main difference lies in the anterior facial field in which technique A uses electron beam throughout while technique B uses a mixture of photon and electron beams. The results demonstrates that technique A delivers higher dose to temporal lobe than technique B. In a course of radical external beam radiotherapy (66 Gy), the mean dose to inferior temporal lobe are 59.29 Gy in technique A and 34.06 Gy in technique B respectively (p < 0.0001). Furthermore, it is found that the temporal lobe dose difference between the two techniques is mainly due to their phase I treatment. (p < 0.0001 for phase I and p = 0.078 for phase II). (authors). 14 refs., 3 tabs., 6 figs.

  4. A Dosimetric Evaluation of Conventional Helmet Field Irradiation Versus Two-Field Intensity-Modulated Radiotherapy Technique

    International Nuclear Information System (INIS)

    Yu, James B.; Shiao, Stephen L.; Knisely, Jonathan

    2007-01-01

    Purpose: To compare dosimetric differences between conventional two-beam helmet field irradiation (external beam radiotherapy, EBRT) of the brain and a two-field intensity-modulated radiotherapy (IMRT) technique. Methods and Materials: Ten patients who received helmet field irradiation at our institution were selected for study. External beam radiotherapy portals were planned per usual practice. Intensity-modulated radiotherapy fields were created using the identical field angles as the EBRT portals. Each brain was fully contoured along with the spinal cord to the bottom of the C2 vertebral body. This volume was then expanded symmetrically by 0.5 cm to construct the planning target volume. An IMRT plan was constructed using uniform optimization constraints. For both techniques, the nominal prescribed dose was 3,000 cGy in 10 fractions of 300 cGy using 6-MV photons. Comparative dose-volume histograms were generated for each patient and analyzed. Results: Intensity-modulated radiotherapy improved dose uniformity over EBRT for whole brain radiotherapy. The mean percentage of brain receiving >105% of dose was reduced from 29.3% with EBRT to 0.03% with IMRT. The mean maximum dose was reduced from 3,378 cGy (113%) for EBRT to 3,162 cGy (105%) with IMRT. The mean percent volume receiving at least 98% of the prescribed dose was 99.5% for the conventional technique and 100% for IMRT. Conclusions: Intensity-modulated radiotherapy reduces dose inhomogeneity, particularly for the midline frontal lobe structures where hot spots occur with conventional two-field EBRT. More study needs to be done addressing the clinical implications of optimizing dose uniformity and its effect on long-term cognitive function in selected long-lived patients

  5. Clinical results of a concomitant boost radiotherapy technique for muscle-invasive bladder cancer

    Energy Technology Data Exchange (ETDEWEB)

    Piet, A H.M.; Hulshof, M C.C.M.; Pieters, B R; Koning, C C.E. [Dept. of Radiation Oncology, Academic Medical Center, Univ. of Amsterdam (Netherlands); Pos, F J [Dept. of Radiation Oncology, The Netherlands Cancer Inst., Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Reijke, T.M. de [Dept. of Urology, Academic Medical Center, Univ. of Amsterdam (Netherlands)

    2008-06-15

    Purpose: to update the results of external radiotherapy with a focal concomitant boost technique on local control and bladder function in patients with muscle-invasive bladder cancer. Patients and methods: the authors retrospectively evaluated 92 elderly or disabled patients with localized T2-4 N0-1 M0 transitional cell carcinoma of the bladder and a median age of 79 years, not suitable for radical surgery and treated between 1994 and 2005. Treatment consisted of a dose of 40 Gy/2 Gy to the small pelvis with a daily concomitant boost of 0.75 Gy to the tumor. Total dose was 55 Gy in 4 weeks. Results: complete remission rate after evaluation by means of cystoscopy at 3 months was 78%. 3-year local control rate amounted to 56%, and 3-year overall survival to 36%. The posttreatment bladder capacity was comparable with the pretreatment capacity and was {>=} 200 ml in 81% of the cases. Mean bladder capacity did not deteriorate at longer follow-up. Conclusion: the local control rate after external beam radiotherapy in elderly patients with a focal concomitant boost for localized muscle-invasive bladder cancer was 56% at 3 years. Functional bladder outcome was good. (orig.)

  6. Clinical results of a concomitant boost radiotherapy technique for muscle-invasive bladder cancer

    International Nuclear Information System (INIS)

    Piet, A.H.M.; Hulshof, M.C.C.M.; Pieters, B.R.; Koning, C.C.E.; Pos, F.J.; Reijke, T.M. de

    2008-01-01

    Purpose: to update the results of external radiotherapy with a focal concomitant boost technique on local control and bladder function in patients with muscle-invasive bladder cancer. Patients and methods: the authors retrospectively evaluated 92 elderly or disabled patients with localized T2-4 N0-1 M0 transitional cell carcinoma of the bladder and a median age of 79 years, not suitable for radical surgery and treated between 1994 and 2005. Treatment consisted of a dose of 40 Gy/2 Gy to the small pelvis with a daily concomitant boost of 0.75 Gy to the tumor. Total dose was 55 Gy in 4 weeks. Results: complete remission rate after evaluation by means of cystoscopy at 3 months was 78%. 3-year local control rate amounted to 56%, and 3-year overall survival to 36%. The posttreatment bladder capacity was comparable with the pretreatment capacity and was ≥ 200 ml in 81% of the cases. Mean bladder capacity did not deteriorate at longer follow-up. Conclusion: the local control rate after external beam radiotherapy in elderly patients with a focal concomitant boost for localized muscle-invasive bladder cancer was 56% at 3 years. Functional bladder outcome was good. (orig.)

  7. Assessment of improved organ at risk sparing for advanced cervix carcinoma utilizing precision radiotherapy techniques

    Energy Technology Data Exchange (ETDEWEB)

    Georg, D.; Georg, P.; Hillbrand, M.; Poetter, R.; Mock, U. [Dept. of Radiotherapy, Medical Univ. AKH, Vienna (Austria)

    2008-11-15

    Purpose: to evaluate the potential benefit of proton therapy and photon based intensity-modulated radiotherapy in comparison to 3-D conformal photon radiotherapy (3D-CRT) in locally advanced cervix cancer. Patients and methods: in five patients with advanced cervix cancer 3D-CRT (four-field box) was compared with intensity modulated photon (IMXT) and proton therapy (IMPT) as well as proton beam therapy (PT) based on passive scattering. Planning target volumes (PTVs) included primary tumor and pelvic and para-aortic lymph nodes. Dose-volume histograms (DVHs) were analyzed for the PTV and various organs at risk (OARs) (rectal wall, bladder, small bowel, colon, femoral heads, and kidneys). In addition dose conformity, dose inhomogeneity and overall volumes of 50% isodoses were assessed. Results: all plans were comparable concerning PTV parameters. Large differences between photon and proton techniques were seen in volumes of the 50% isodoses and conformity indices. DVH for colon and small bowel were significantly improved with PT and IMPT compared to IMXT, with D{sub mean} reductions of 50-80%. Doses to kidneys and femoral heads could also be substantially reduced with PT and IMPT. Sparing of rectum and bladder was superior with protons as well but less pronounced. Conclusion: proton beam RT has significant potential to improve treatment related side effects in the bowel compared to photon beam RT in patients with advanced cervix carcinoma. (orig.)

  8. Assessment of improved organ at risk sparing for advanced cervix carcinoma utilizing precision radiotherapy techniques

    International Nuclear Information System (INIS)

    Georg, D.; Georg, P.; Hillbrand, M.; Poetter, R.; Mock, U.

    2008-01-01

    Purpose: to evaluate the potential benefit of proton therapy and photon based intensity-modulated radiotherapy in comparison to 3-D conformal photon radiotherapy (3D-CRT) in locally advanced cervix cancer. Patients and methods: in five patients with advanced cervix cancer 3D-CRT (four-field box) was compared with intensity modulated photon (IMXT) and proton therapy (IMPT) as well as proton beam therapy (PT) based on passive scattering. Planning target volumes (PTVs) included primary tumor and pelvic and para-aortic lymph nodes. Dose-volume histograms (DVHs) were analyzed for the PTV and various organs at risk (OARs) (rectal wall, bladder, small bowel, colon, femoral heads, and kidneys). In addition dose conformity, dose inhomogeneity and overall volumes of 50% isodoses were assessed. Results: all plans were comparable concerning PTV parameters. Large differences between photon and proton techniques were seen in volumes of the 50% isodoses and conformity indices. DVH for colon and small bowel were significantly improved with PT and IMPT compared to IMXT, with D mean reductions of 50-80%. Doses to kidneys and femoral heads could also be substantially reduced with PT and IMPT. Sparing of rectum and bladder was superior with protons as well but less pronounced. Conclusion: proton beam RT has significant potential to improve treatment related side effects in the bowel compared to photon beam RT in patients with advanced cervix carcinoma. (orig.)

  9. External radiotherapy in macular degeneration: Our technique, dosimetric calculation, and preliminary results

    International Nuclear Information System (INIS)

    Akmansu, M.; Dirican, Bahar; Oeztuerk, Berrin; Egehan, Ibrahim; Subasi, Mahmut; Or, Meral

    1998-01-01

    Purpose: This study was performed to determine the toxicity and efficacy of external-beam radiotherapy in patients with age-related subfoveal neovascularization. Methods and Materials: Between January 1996 and September 1996, 25 patients with a mean age of 70.5 (60-84) years were enrolled. All patients underwent fluorescein angiographic evaluation and documentation of their neovascular disease prior to irradiation. A total of 25 patients were treated with a total dose of 12 Gy in 6 fractions over 8 days. We used a lens-sparing technique and patients were treated with a single lateral 6-MV photon beam. To assess the risk of radiation carcinogenesis after treatment of age-related subfoveal neovascularization, we estimated the effective dose for a standard patient on the basis of tissue-weighting factors as defined by the International Commission on Radiological Protection (ICRP). The calculations were made with TLD on a male randophantom. The lens dose was found to be 0.217 Gy per fraction. Results: No significant acute morbidity was noted. Visual acuity was maintained or improved in 76% and 80% of treated patients at their 1- and 3-month follow-up examinations, respectively. On angiographic imaging, there was stabilization of subfoveal neovascular membranes in 23 patients (92%) at 3 months after irradiation. Conclusion: Our observations on these 25 patients in this study indicate that many patients will have improved or stable vision after radiotherapy treatment with low-dose irradiation

  10. Three dimensional conformal radiotherapy for synchronous bilateral breast irradiation using a mono iso-center technique

    Science.gov (United States)

    Mani, Karthick Raj; Basu, Saumen; Bhuiyan, Md Anisuzzaman; Ahmed, Sharif; Sumon, Mostafa Aziz; Haque, Kh Anamul; Sengupta, Ashim Kumar; Un Nabi, Md Rashid; Das, K. J. Maria

    2017-06-01

    Objective: The purpose of this study is to demonstrate the synchronous bilateral breast irradiation radiotherapy technique using a single isocenter. Materials and Methods: Six patients of synchronous bilateral breast were treated with single isocenter technique from February 2011 to June 2016. All the patients underwent a CT-simulation using appropriate positioning device. Target volumes and critical structures like heart, lung, esophagus, thyroid, etc., were delineated slice by slice in the CT data. An isocenter was placed above the sternum on the skin and both medial tangential and lateral tangential of the breast / chest wall were created using asymmetrical jaws to avoid the beam divergence through the lung and heart. The field weighting were adjusted manually to obtain a homogenous dose distribution. The planning objectives were to deliver uniform doses around the target and keep the doses to the organ at risk within the permissible limit. The beam energy of 6 MV or combination of 6 MV and 15 MV photons were used in the tangential fields according to the tangential separation. Boluses were used for all the mastectomy patients to increase the doses on the chest wall. In addition to that enhanced dynamic wedge and field in field technique were also used to obtain a homogenous distribution around the target volume and reduce the hot spots. The isocenter was just kept on the skin, such that the beam junctions will be overlapped only on the air just above the sternum. Acute toxicity during the treatment and late toxicity were recorded during the patient's follow-up. Results: During the radiotherapy treatment follow-up there were no acute skin reactions in the field junctions, but one patient had grade 1 esophagitis and two patients had grade 2 skin reactions in the chest wall. With a median follow-up of 38.5 months (range: 8 - 49 months), no patients had a local recurrence, but one patients with triple negative disease had a distant metastases in brain and died

  11. Quality Assurance Needs for Modern Image-Based Radiotherapy: Recommendations From 2007 Interorganizational Symposium on 'Quality Assurance of Radiation Therapy: Challenges of Advanced Technology'

    International Nuclear Information System (INIS)

    Williamson, Jeffrey F.; Dunscombe, Peter B.; Sharpe, Michael B.; Thomadsen, Bruce R.; Purdy, James A.; Deye, James A.

    2008-01-01

    This report summarizes the consensus findings and recommendations emerging from 2007 Symposium, 'Quality Assurance of Radiation Therapy: Challenges of Advanced Technology.' The Symposium was held in Dallas February 20-22, 2007. The 3-day program, which was sponsored jointly by the American Society for Therapeutic Radiology and Oncology (ASTRO), American Association of Physicists in Medicine (AAPM), and National Cancer Institute (NCI), included >40 invited speakers from the radiation oncology and industrial engineering/human factor communities and attracted nearly 350 attendees, mostly medical physicists. A summary of the major findings follows. The current process of developing consensus recommendations for prescriptive quality assurance (QA) tests remains valid for many of the devices and software systems used in modern radiotherapy (RT), although for some technologies, QA guidance is incomplete or out of date. The current approach to QA does not seem feasible for image-based planning, image-guided therapies, or computer-controlled therapy. In these areas, additional scientific investigation and innovative approaches are needed to manage risk and mitigate errors, including a better balance between mitigating the risk of catastrophic error and maintaining treatment quality, complimenting the current device-centered QA perspective by a more process-centered approach, and broadening community participation in QA guidance formulation and implementation. Industrial engineers and human factor experts can make significant contributions toward advancing a broader, more process-oriented, risk-based formulation of RT QA. Healthcare administrators need to appropriately increase personnel and ancillary equipment resources, as well as capital resources, when new advanced technology RT modalities are implemented. The pace of formalizing clinical physics training must rapidly increase to provide an adequately trained physics workforce for advanced technology RT. The specific

  12. Quality assurance needs for modern image-based radiotherapy: recommendations from 2007 interorganizational symposium on "quality assurance of radiation therapy: challenges of advanced technology".

    Science.gov (United States)

    Williamson, Jeffrey F; Dunscombe, Peter B; Sharpe, Michael B; Thomadsen, Bruce R; Purdy, James A; Deye, James A

    2008-01-01

    This report summarizes the consensus findings and recommendations emerging from 2007 Symposium, "Quality Assurance of Radiation Therapy: Challenges of Advanced Technology." The Symposium was held in Dallas February 20-22, 2007. The 3-day program, which was sponsored jointly by the American Society for Therapeutic Radiology and Oncology (ASTRO), American Association of Physicists in Medicine (AAPM), and National Cancer Institute (NCI), included >40 invited speakers from the radiation oncology and industrial engineering/human factor communities and attracted nearly 350 attendees, mostly medical physicists. A summary of the major findings follows. The current process of developing consensus recommendations for prescriptive quality assurance (QA) tests remains valid for many of the devices and software systems used in modern radiotherapy (RT), although for some technologies, QA guidance is incomplete or out of date. The current approach to QA does not seem feasible for image-based planning, image-guided therapies, or computer-controlled therapy. In these areas, additional scientific investigation and innovative approaches are needed to manage risk and mitigate errors, including a better balance between mitigating the risk of catastrophic error and maintaining treatment quality, complimenting the current device-centered QA perspective by a more process-centered approach, and broadening community participation in QA guidance formulation and implementation. Industrial engineers and human factor experts can make significant contributions toward advancing a broader, more process-oriented, risk-based formulation of RT QA. Healthcare administrators need to appropriately increase personnel and ancillary equipment resources, as well as capital resources, when new advanced technology RT modalities are implemented. The pace of formalizing clinical physics training must rapidly increase to provide an adequately trained physics workforce for advanced technology RT. The specific

  13. External radiotherapy for circumscribed choroidal haemangiomas using a modified retinoblastoma technique

    International Nuclear Information System (INIS)

    Eide, N.; Syrdalen, P.; Tausjoe, J.; Tveraa, K.

    1995-01-01

    This report describes two cases of circumscribed choroidal haemangiomas involving the fovea, complicated by serous retinal detachment. Laser photocoagulation, generally accepted as the treatment of choice for choroidal haemangioma, was considered either to be of no visual benefit or a risk for jeopardizing vision further due to the subfoveolar lesions. Fractionated radiotherapy using a lens-sparing, modified retinoblastoma technique, was given, using circular fields of 15 mm diameter. The dose was 24 Gy in 8 fractions. In both eyes the retina reattached completely. The visual acuity improved markedly in the first, and was restored to the prior level in the second. Normalization of a high intraocular pressure was also achieved in the second case. We believe this method to be a reasonable and effective therapy for some choroidal haemangiomas after careful individual consideration. (au) 17 refs

  14. Determination of the optimal method for the field-in-field technique in breast tangential radiotherapy

    International Nuclear Information System (INIS)

    Tanaka, Hidekazu; Hayashi, Shinya; Hoshi, Hiroaki

    2014-01-01

    Several studies have reported the usefulness of the field-in-field (FIF) technique in breast radiotherapy. However, the methods for the FIF technique used in these studies vary. These methods were classified into three categories. We simulated a radiotherapy plan with each method and analyzed the outcomes. In the first method, a pair of subfields was added to each main field: the single pair of subfields method (SSM). In the second method, three pairs of subfields were added to each main field: the multiple pairs of subfields method (MSM). In the third method, subfields were alternately added: the alternate subfields method (ASM). A total of 51 patients were enrolled in this study. The maximum dose to the planning target volume (PTV) (Dmax) and the volumes of the PTV receiving 100% of the prescription dose (V100%) were calculated. The thickness of the breast between the chest wall and skin surface was measured, and patients were divided into two groups according to the median. In the overall series, the average V100% with ASM (60.3%) was significantly higher than with SSM (52.6%) and MSM (48.7%). In the thin breast group as well, the average V100% with ASM (57.3%) and SSM (54.2%) was significantly higher than that with MSM (43.3%). In the thick breast group, the average V100% with ASM (63.4%) was significantly higher than that with SSM (51.0%) and MSM (54.4%). ASM resulted in better dose distribution, regardless of the breast size. Moreover, planning for ASM required a relatively short time. ASM was considered the most preferred method. (author)

  15. Hyperfractionated Radiotherapy with Concomitant Boost Technique for Unresectable Non-Small Cell Carcinoma of the Lung

    International Nuclear Information System (INIS)

    Chun, Ha Chung; Lee, Myung Za

    1991-01-01

    Twenty five patients with unresectable non-small cell carcinoma of the lung have been treated with hyperfractionated radiotherapy with concomitant boost technique since September, 1989. Those patients with history of previous surgery or chemotherapy, pleural effusion or significant weight loss (greater than 10% of body weight) were excluded from the study. Initially, 27 Gy were delivered in 15 fractions in 3 weeks to the large field. Thereafter, large field received 1.8 Gy and cone down boost field received 1.4Gy with twice a day fractinations up to 49.4Gy. After 49.4Gy, only boost field was treated twice a day with 1.8 and 1.4 Gy. Total tumor doses were 62.2Gy for 12 patients and 65.4Gy for remaining 13 patients. Follow up period was ranged from 6 to 24 month. Actuarial survival rates at 6, 12, and 18 month were 88%, 62%, and 38%, respectively. Corresponding disease free survival rates were 88%, 41%, and 21%, respectively. Actuarial cumulative local failure rates at 9,12 and 15 month were 36%, 42%, and 59%, respectively. No significant increase of acute or late complications including radiation pneumonitis was noted with maximum follow up of 24 month. Although the longer follow up is needed, it is worthwhile to try the prospective randomized study to evaluate the efficacy of hyperfractionated radiotherapy with concomitant boost technique for unresectable non-small cell lung cancers in view of excellent tolerance of this treatment. In the future, further increase of total radiation dose might be necessary to improve local control for non-small cell lung cancer

  16. Is modern external beam radiotherapy with androgen deprivation therapy still a viable alternative for prostate cancer in an era of robotic surgery and brachytherapy: a comparison of Australian series

    International Nuclear Information System (INIS)

    Wilcox, Shea W.; Last, Andrew J.; Aherne, Noel J.; McLachlan, Craig S.; McKay, Michael J.; Shakespeare, Thomas P.

    2015-01-01

    We compare the results of modern external-beam radiotherapy (EBRT), using combined androgen deprivation and dose-escalated intensity-modulated radiotherapy with MRI-CT fusion and daily image guidance with fiducial markers (DE-IG-IMRT), with recently published Australian series of brachytherapy and surgery. Five-year actuarial biochemical disease-free survival (bDFS), metastasis-free survival (MFS) and prostate cancer-specific survival (PCaSS) were calculated for 675 patients treated with DE-IG-IMRT and androgen deprivation therapy (ADT). Patients had intermediate-risk (IR) and high-risk (HR) disease. A search was conducted identifying Australian reports from 2005 onwards of IR and HR patients treated with surgery or brachytherapy, reporting actuarial outcomes at 3 years or later. With a median follow-up of 59 months, our 5-year bDFS was 93.3% overall: 95.5% for IR and 91.3% for HR disease. MFS was 96.9% overall (99.0% IR, 94.9% HR), and PCaSS was 98.8% overall (100% IR, 97.7% HR). Prevalence of Grade 2 genitourinary and gastrointestinal toxicity at 5 years was 1.3% and 1.6%, with 0.3% Grade 3 genitourinary toxicity and no Grade 3 gastrointestinal toxicity. Eight reports of brachytherapy and surgery were identified. The HDR brachytherapy series' median 5-year bDFS was 82.5%, MFS 90.0% and PCaSS 97.9%. One surgical series reported 5-year bDFS of 65.5% for HR patients. One LDR series reported 5-year bDFS of 85% for IR patients. Modern EBRT is at least as effective as modern Australian surgical and brachytherapy techniques. All patients considering treatment for localised prostate cancer should be referred to a radiation oncologist to discuss EBRT as an equivalent option.

  17. Is modern external beam radiotherapy with androgen deprivation therapy still a viable alternative for prostate cancer in an era of robotic surgery and brachytherapy: a comparison of Australian series.

    Science.gov (United States)

    Wilcox, Shea William; Aherne, Noel J; McLachlan, Craig Steven; McKay, Michael J; Last, Andrew J; Shakespeare, Thomas P

    2015-02-01

    We compare the results of modern external-beam radiotherapy (EBRT), using combined androgen deprivation and dose-escalated intensity-modulated radiotherapy with MRI-CT fusion and daily image guidance with fiducial markers (DE-IG-IMRT), with recently published Australian series of brachytherapy and surgery. Five-year actuarial biochemical disease-free survival (bDFS), metastasis-free survival (MFS) and prostate cancer-specific survival (PCaSS) were calculated for 675 patients treated with DE-IG-IMRT and androgen deprivation therapy (ADT). Patients had intermediate-risk (IR) and high-risk (HR) disease. A search was conducted identifying Australian reports from 2005 onwards of IR and HR patients treated with surgery or brachytherapy, reporting actuarial outcomes at 3 years or later. With a median follow-up of 59 months, our 5-year bDFS was 93.3% overall: 95.5% for IR and 91.3% for HR disease. MFS was 96.9% overall (99.0% IR, 94.9% HR), and PCaSS was 98.8% overall (100% IR, 97.7% HR). Prevalence of Grade 2 genitourinary and gastrointestinal toxicity at 5 years was 1.3% and 1.6%, with 0.3% Grade 3 genitourinary toxicity and no Grade 3 gastrointestinal toxicity. Eight reports of brachytherapy and surgery were identified. The HDR brachytherapy series' median 5-year bDFS was 82.5%, MFS 90.0% and PCaSS 97.9%. One surgical series reported 5-year bDFS of 65.5% for HR patients. One LDR series reported 5-year bDFS of 85% for IR patients. Modern EBRT is at least as effective as modern Australian surgical and brachytherapy techniques. All patients considering treatment for localised prostate cancer should be referred to a radiation oncologist to discuss EBRT as an equivalent option. © 2015 The Royal Australian and New Zealand College of Radiologists.

  18. Comparative study of different Al_2O_3:C dosimeters using OSL technique for dosimetry on Volumetric Modulated Arc Radiotherapy Treatment (VMAT)

    International Nuclear Information System (INIS)

    Villani, Daniel; Campos, LetIcia L.; Mancini, Anselmo; Haddad, Cecilia M.K.

    2016-01-01

    In modern radiotherapy, the VMAT technique has become a successful treatment alternative. Due to its complexity, a quality assurance program must be established by evaluating, among other items, the dosimetric factors. This paper aims to compare the performance between the OSL aluminum oxide (Al_2O_3:C) nanoDot™ dosimeters (Inlight™ system) manufactured by Landauer Inc. and TLD-500 Al_2O_3:C dosimeters manufactured by Rexon™ for VMAT dosimetry using an anthropomorphic phantom. The results showed that both type of Al_2O_3:C dosimeters presented good repeatability and agreement between the doses measured and calculated by planning system. However, the need of sophisticated readers to OSL analysis of the TLD-500, turns it less practical for routine usage, comparing to Inlight™ system. (author)

  19. Accuracy of image-guided radiotherapy of prostate cancer based on the BeamCath urethral catheter technique

    DEFF Research Database (Denmark)

    Poulsen, Per Rugaard; Fokdal, Lars; Petersen, Jørgen B.B.

    2007-01-01

    BACKGROUND AND PURPOSE: To examine the accuracy of the BeamCath urethral catheter technique for prostate localization during radiotherapy. MATERIALS AND METHODS: Sixty-four patients were CT scanned twice with the BeamCath catheter, and once without the catheter. The catheter contains radiopaque...

  20. Anatomic and Pathologic Variability During Radiotherapy for a Hybrid Active Breath-Hold Gating Technique

    International Nuclear Information System (INIS)

    Glide-Hurst, Carri K.; Gopan, Ellen; Hugo, Geoffrey D.

    2010-01-01

    Purpose: To evaluate intra- and interfraction variability of tumor and lung volume and position using a hybrid active breath-hold gating technique. Methods and Materials: A total of 159 repeat normal inspiration active breath-hold CTs were acquired weekly during radiotherapy for 9 lung cancer patients (12-21 scans per patient). A physician delineated the gross tumor volume (GTV), lungs, and spinal cord on the first breath-hold CT, and contours were propagated semiautomatically. Intra- and interfraction variability of tumor and lung position and volume were evaluated. Tumor centroid and border variability were quantified. Results: On average, intrafraction variability of lung and GTV centroid position was 0.1). Increases in free-breathing tidal volume were associated with increases in breath-hold ipsilateral lung volume (p < 0.05). Conclusions: The breath-hold technique was reproducible within 2 mm during each fraction. Interfraction variability of GTV position and shape was substantial because of tumor volume and breath-hold lung volume change during therapy. These results support the feasibility of a hybrid breath-hold gating technique and suggest that online image guidance would be beneficial.

  1. Investigation of normal tissue complication probabilities in prostate and partial breast irradiation radiotherapy techniques

    International Nuclear Information System (INIS)

    Bezak, E.; Takam, R.; Bensaleh, S.; Yeoh, E.; Marcu, L.

    2011-01-01

    Full text: Normal- Tissue-Complication Probabilities of rectum, bladder and urethra following various radiation techniques for prostate cancer were evaluated using the relative-seriality and Lyman models. NTCPs of lungs, heart and skin, their dependence on sourceposition, balloon-deformation were also investigated for HDR mammosite brachytherapy. The prostate treatment techniques included external three dimentional conformal-radiotherapy, Low-Dose-Rate brachytherapy (1-125), High-Dose-Rate brachytherapy (Ir-I92). Dose- Volume-Histograms of critical structures for prostate and breast radiotherapy, retrieved from corresponding treatment planning systems, were converted to Biological Effective Dose (BEffD)-based and Equivalent Dose(Deq)-based DVHs to account for differences in radiation delivery and fractionation schedule. Literature-based model parameters were used to calculate NTCPs. Hypofractionated 3D-CRT (2.75 Gy/fraction, total dose 55 Gy) NTCPs of rectum, bladder and urethra were less than those for standard fractionated 4-field 3D-CRT (2-Gy/fraction, 64 Gy) and dose-escalated 4- and 5-field 3D-CRT (74 Gy). Rectal and bladder NTCPs (5.2% and 6.6%) following the dose-escalated 4-field 3D-CRT (74 Gy) were the highest among analyzed techniques. The average NTCP for rectum and urethra were 0.6% and 24.7% for LDRBT and 0.5% and 11.2% for HDR-BT. For Mammosite, NTCP was estimated to be 0.1 %, 0.1 %, 1.2% and 3.5% for skin desquamation, erythema, telangiectasia and fibrosis respectively (the source positioned at the balloon centre). A 4 mm Mammosite-balloon deformation leads to overdosing of PTV regions by ∼40%, resulting in excessive skin dose and increased NTCP. Conclusions Prostate brachytherapy resulted in NTCPs lower compared to external beam techniques. Mammosite-brachytherapy resulted in no heart/lung complications regardless of balloon deformation. However, 4 mm deformation caused 0.6% increase in tissue fibrosis NTCP.

  2. A singular value decomposition linear programming (SVDLP) optimization technique for circular cone based robotic radiotherapy

    Science.gov (United States)

    Liang, Bin; Li, Yongbao; Wei, Ran; Guo, Bin; Xu, Xuang; Liu, Bo; Li, Jiafeng; Wu, Qiuwen; Zhou, Fugen

    2018-01-01

    With robot-controlled linac positioning, robotic radiotherapy systems such as CyberKnife significantly increase freedom of radiation beam placement, but also impose more challenges on treatment plan optimization. The resampling mechanism in the vendor-supplied treatment planning system (MultiPlan) cannot fully explore the increased beam direction search space. Besides, a sparse treatment plan (using fewer beams) is desired to improve treatment efficiency. This study proposes a singular value decomposition linear programming (SVDLP) optimization technique for circular collimator based robotic radiotherapy. The SVDLP approach initializes the input beams by simulating the process of covering the entire target volume with equivalent beam tapers. The requirements on dosimetry distribution are modeled as hard and soft constraints, and the sparsity of the treatment plan is achieved by compressive sensing. The proposed linear programming (LP) model optimizes beam weights by minimizing the deviation of soft constraints subject to hard constraints, with a constraint on the l 1 norm of the beam weight. A singular value decomposition (SVD) based acceleration technique was developed for the LP model. Based on the degeneracy of the influence matrix, the model is first compressed into lower dimension for optimization, and then back-projected to reconstruct the beam weight. After beam weight optimization, the number of beams is reduced by removing the beams with low weight, and optimizing the weights of the remaining beams using the same model. This beam reduction technique is further validated by a mixed integer programming (MIP) model. The SVDLP approach was tested on a lung case. The results demonstrate that the SVD acceleration technique speeds up the optimization by a factor of 4.8. Furthermore, the beam reduction achieves a similar plan quality to the globally optimal plan obtained by the MIP model, but is one to two orders of magnitude faster. Furthermore, the SVDLP

  3. A singular value decomposition linear programming (SVDLP) optimization technique for circular cone based robotic radiotherapy.

    Science.gov (United States)

    Liang, Bin; Li, Yongbao; Wei, Ran; Guo, Bin; Xu, Xuang; Liu, Bo; Li, Jiafeng; Wu, Qiuwen; Zhou, Fugen

    2018-01-05

    With robot-controlled linac positioning, robotic radiotherapy systems such as CyberKnife significantly increase freedom of radiation beam placement, but also impose more challenges on treatment plan optimization. The resampling mechanism in the vendor-supplied treatment planning system (MultiPlan) cannot fully explore the increased beam direction search space. Besides, a sparse treatment plan (using fewer beams) is desired to improve treatment efficiency. This study proposes a singular value decomposition linear programming (SVDLP) optimization technique for circular collimator based robotic radiotherapy. The SVDLP approach initializes the input beams by simulating the process of covering the entire target volume with equivalent beam tapers. The requirements on dosimetry distribution are modeled as hard and soft constraints, and the sparsity of the treatment plan is achieved by compressive sensing. The proposed linear programming (LP) model optimizes beam weights by minimizing the deviation of soft constraints subject to hard constraints, with a constraint on the l 1 norm of the beam weight. A singular value decomposition (SVD) based acceleration technique was developed for the LP model. Based on the degeneracy of the influence matrix, the model is first compressed into lower dimension for optimization, and then back-projected to reconstruct the beam weight. After beam weight optimization, the number of beams is reduced by removing the beams with low weight, and optimizing the weights of the remaining beams using the same model. This beam reduction technique is further validated by a mixed integer programming (MIP) model. The SVDLP approach was tested on a lung case. The results demonstrate that the SVD acceleration technique speeds up the optimization by a factor of 4.8. Furthermore, the beam reduction achieves a similar plan quality to the globally optimal plan obtained by the MIP model, but is one to two orders of magnitude faster. Furthermore, the SVDLP

  4. Comparison of static conformal field with multiple noncoplanar arc techniques for stereotactic radiosurgery or stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Hamilton, Russell J.; Kuchnir, Franca T.; Sweeney, Patrick; Rubin, Steven J.; Dujovny, Manuel; Pelizzari, Charles A.; Chen, George T. Y.

    1995-01-01

    Purpose: Compare the use of static conformal fields with the use of multiple noncoplanar arcs for stereotactic radiosurgery or stereotactic radiotherapy treatment of intracranial lesions. Evaluate the efficacy of these treatment techniques to deliver dose distributions comparable to those considered acceptable in current radiotherapy practice. Methods and Materials: A previously treated radiosurgery case of a patient presenting with an irregularly shaped intracranial lesion was selected. Using a three-dimensional (3D) treatment-planning system, treatment plans using a single isocenter multiple noncoplanar arc technique and multiple noncoplanar conformal static fields were generated. Isodose distributions and dose volume histograms (DVHs) were computed for each treatment plan. We required that the 80% (of maximum dose) isodose surface enclose the target volume for all treatment plans. The prescription isodose was set equal to the minimum target isodose. The DVHs were analyzed to evaluate and compare the different treatment plans. Results: The dose distribution in the target volume becomes more uniform as the number of conformal fields increases. The volume of normal tissue receiving low doses (> 10% of prescription isodose) increases as the number of static fields increases. The single isocenter multiple arc plan treats the greatest volume of normal tissue to low doses, approximately 1.6 times more volume than that treated by four static fields. The volume of normal tissue receiving high (> 90% of prescription isodose) and intermediate (> 50% of prescription isodose) doses decreases by 29 and 22%, respectively, as the number of static fields is increased from four to eight. Increasing the number of static fields to 12 only further reduces the high and intermediate dose volumes by 10 and 6%, respectively. The volume receiving the prescription dose is more than 3.5 times larger than the target volume for all treatment plans. Conclusions: Use of a multiple noncoplanar

  5. An imaging evaluation of the simultaneously integrated boost breast radiotherapy technique

    Energy Technology Data Exchange (ETDEWEB)

    Turley, Jessica; Claridge Mackonis, Elizabeth [Department of Radiation Oncology, Royal Prince Alfred Hospital, Camperdown, New South Wales (Australia)

    2015-09-15

    To evaluate in-field megavoltage (MV) imaging of simultaneously integrated boost (SIB) breast fields to determine its feasibility in treatment verification for the SIB breast radiotherapy technique, and to assess whether the current-imaging protocol and treatment margins are sufficient. For nine patients undergoing SIB breast radiotherapy, in-field MV images of the SIB fields were acquired on days that regular treatment verification imaging was performed. The in-field images were matched offline according to the scar wire on digitally reconstructed radiographs. The offline image correction results were then applied to a margin recipe formula to calculate safe margins that account for random and systematic uncertainties in the position of the boost volume when an offline correction protocol has been applied. After offline assessment of the acquired images, 96% were within the tolerance set in the current department-imaging protocol. Retrospectively performing the maximum position deviations on the Eclipse™ treatment planning system demonstrated that the clinical target volume (CTV) boost received a minimum dose difference of 0.4% and a maximum dose difference of 1.4% less than planned. Furthermore, applying our results to the Van Herk margin formula to ensure that 90% of patients receive 95% of the prescribed dose, the calculated CTV margins were comparable to the current departmental procedure used. Based on the in-field boost images acquired and the feasible application of these results to the margin formula the current CTV-planning target volume margins used are appropriate for the accurate treatment of the SIB boost volume without additional imaging.

  6. An imaging evaluation of the simultaneously integrated boost breast radiotherapy technique

    International Nuclear Information System (INIS)

    Turley, Jessica; Claridge Mackonis, Elizabeth

    2015-01-01

    To evaluate in-field megavoltage (MV) imaging of simultaneously integrated boost (SIB) breast fields to determine its feasibility in treatment verification for the SIB breast radiotherapy technique, and to assess whether the current-imaging protocol and treatment margins are sufficient. For nine patients undergoing SIB breast radiotherapy, in-field MV images of the SIB fields were acquired on days that regular treatment verification imaging was performed. The in-field images were matched offline according to the scar wire on digitally reconstructed radiographs. The offline image correction results were then applied to a margin recipe formula to calculate safe margins that account for random and systematic uncertainties in the position of the boost volume when an offline correction protocol has been applied. After offline assessment of the acquired images, 96% were within the tolerance set in the current department-imaging protocol. Retrospectively performing the maximum position deviations on the Eclipse™ treatment planning system demonstrated that the clinical target volume (CTV) boost received a minimum dose difference of 0.4% and a maximum dose difference of 1.4% less than planned. Furthermore, applying our results to the Van Herk margin formula to ensure that 90% of patients receive 95% of the prescribed dose, the calculated CTV margins were comparable to the current departmental procedure used. Based on the in-field boost images acquired and the feasible application of these results to the margin formula the current CTV-planning target volume margins used are appropriate for the accurate treatment of the SIB boost volume without additional imaging

  7. Breathing adapted radiotherapy: final clinic results of the program for the support to costly innovating techniques (Stic) of 2003

    International Nuclear Information System (INIS)

    Giraud, P.; Giraud, P.; Morvan, E.; Djadi-Prat, J.; Rosenwald, J.C.; Carrere, M.O.

    2010-01-01

    The authors report the comparison, from a clinic point of view, between breathing adapted conformational radiotherapy (BART) and conventional conformational radiotherapy, in the case of lung and breast cancers. The assessment comprised a clinic examination, a thoracic radiography, breathing functional tests, a thoracic scanography at different moments (3, 6, 12, 18 and 24 months), and dosimetric criteria for tumour target volumes and the different thoracic organs at risk. Data have been collected among more than six hundred patients. Breathing adapted techniques allow acute and late toxicity to be reduced, notably for the lung, heart and oesophagus during a lung irradiation. They are less interesting for mammary irradiation, but could be important for a radiotherapy of the left breast. Short communication

  8. Simple Carotid-Sparing Intensity-Modulated Radiotherapy Technique and Preliminary Experience for T1-2 Glottic Cancer

    International Nuclear Information System (INIS)

    Rosenthal, David I.; Fuller, Clifton D.; Barker, Jerry L.; Mason, Bryan M.S.; Garcia, John A. C.; Lewin, Jan S.; Holsinger, F. Christopher; Stasney, C. Richard; Frank, Steven J.; Schwartz, David L.; Morrison, William H.; Garden, Adam S.; Ang, K. Kian

    2010-01-01

    Purpose: To investigate the dosimetry and feasibility of carotid-sparing intensity-modulated radiotherapy (IMRT) for early glottic cancer and to report preliminary clinical experience. Methods and Materials: Digital Imaging and Communications in Medicine radiotherapy (DICOM-RT) datasets from 6 T1-2 conventionally treated glottic cancer patients were used to create both conventional IMRT plans. We developed a simplified IMRT planning algorithm with three fields and limited segments. Conventional and IMRT plans were compared using generalized equivalent uniform dose and dose-volume parameters for in-field carotid arteries, target volumes, and organs at risk. We have treated 11 patients with this simplified IMRT technique. Results: Intensity-modulated radiotherapy consistently reduced radiation dose to the carotid arteries (p < 0.05) while maintaining the clinical target volume coverage. With conventional planning, median carotid V35, V50, and V63 were 100%, 100%, and 69.0%, respectively. With IMRT planning these decreased to 2%, 0%, and 0%, respectively (p < 0.01). Radiation planning and treatment times were similar for conventional radiotherapy and IMRT. Treatment results have been excellent thus far. Conclusions: Intensity-modulated radiotherapy significantly reduced unnecessary radiation dose to the carotid arteries compared with conventional lateral fields while maintaining clinical target volume coverage. Further experience and longer follow-up will be required to demonstrate outcomes for cancer control and carotid artery effects.

  9. A cosmetic evaluation of breast cancer treatment: A randomized study of radiotherapy boost technique

    International Nuclear Information System (INIS)

    Vass, Sylvie; Bairati, Isabelle

    2005-01-01

    Purpose: To compare cosmetic results of two different radiotherapy (RT) boost techniques used in the treatment of breast cancer after whole breast radiotherapy and to identify factors affecting cosmetic outcomes. Methods and Materials: Between 1996 and 1998, 142 patients with Stage I and II breast cancer were treated with breast conservative surgery and adjuvant RT. Patients were then randomly assigned to receive a boost dose of 15 Gy delivered to the tumor bed either by iridium 192, or a combination of photons and electrons. Cosmetic evaluations were done on a 6-month basis, with a final evaluation at 36 months after RT. The evaluations were done using a panel of global and specific subjective scores, a digitized scoring system using the breast retraction assessment (BRA) measurement, and a patient's self-assessment evaluation. As cosmetic results were graded according to severity, the comparison of boost techniques was done using the ordinal logistic regression model. Adjusted odds ratios (OR) and their 95% confidence intervals (CI) are presented. Results: At 36 months of follow-up, there was no significant difference between the two groups with respect to the global subjective cosmetic outcome (OR = 1.40; 95%CI = 0.69-2.85, p = 0.35). Good to excellent scores were observed in 65% of implant patients and 62% of photon/electron patients. At 24 months and beyond, telangiectasia was more severe in the implant group with an OR of 9.64 (95%CI = 4.05-22.92, p < 0.0001) at 36 months. The only variable associated with a worse global cosmetic outcome was the presence of concomitant chemotherapy (OR = 3.87; 95%CI = 1.74-8.62). The BRA value once adjusted for age, concomitant chemotherapy, and boost volume showed a positive association with the boost technique. The BRA value was significantly greater in the implant group (p 0.03). There was no difference in the patient's final self-assessment score between the two groups. Three variables were statistically associated with

  10. A survey of techniques to reduce and manage external beam radiation-induced xerostomia in British oncology and radiotherapy departments

    International Nuclear Information System (INIS)

    Macknelly, Andrew; Day, Jane

    2009-01-01

    Xerostomia is the most common side effect of external beam radiotherapy to the head and neck [Anand A, Jain J, Negi P, Chaudhoory A, Sinha S, Choudhury P, et-al. Can dose reduction to one parotid gland prevent xerostomia? - A feasibility study for locally advanced head and neck cancer patients treated with intensity-modulated radiotherapy. Clinical Oncology 2006;18(6):497-504.]. A survey was carried out in British oncology departments to determine what treatment regimes, to minimise xerostomia, are used for patients with head-and-neck cancers treated with external beam radiotherapy. A semi-structured questionnaire consisting of both quantitative and qualitative questions was designed that asked departments which of the identified methods they used, why a method might not be currently employed, and whether its use had ever been considered. The study found that there are wide disparities between the techniques employed by oncology departments to avoid and reduce xerostomia in patients with cancers of the head and neck. The National Institute of Clinical Health and Excellence, [National Institute for Clinical Health and Excellence (NICE). Improving outcomes in head and neck cancers: the manual. London: Office of Public Sector Information; 2004.] for example, recommends that patients are given dental care and dietary advice but some departments did not appear to be doing this. Less than half of departments stated that they offer complementary therapies and less than 40% prescribed pilocarpine, a saliva-stimulant. Only two respondents stated that they use amifostine, a radioprotector, during radiotherapy treatment to the head and neck. The results also suggested a move toward using Intensity Modulated Radiotherapy (IMRT) for treating head-and-neck cancers which offers better normal tissue sparing than three-dimensional conformal radiotherapy. [Anand A, Jain J, Negi P, Chaudhoory A, Sinha S, Choudhury P, et al. Can dose reduction to one parotid gland prevent xerostomia

  11. Learning mediastinoscopy: the need for education, experience and modern techniques--interdependency of the applied technique and surgeon's training level.

    Science.gov (United States)

    Walles, Thorsten; Friedel, Godehard; Stegherr, Tobias; Steger, Volker

    2013-04-01

    Mediastinoscopy represents the gold standard for invasive mediastinal staging. While learning and teaching the surgical technique are challenging due to the limited accessibility of the operation field, both benefited from the implementation of video-assisted techniques. However, it has not been established yet whether video-assisted mediastinoscopy improves the mediastinal staging in itself. Retrospective single-centre cohort analysis of 657 mediastinoscopies performed at a specialized tertiary care thoracic surgery unit from 1994 to 2006. The number of specimens obtained per procedure and per lymph node station (2, 4, 7, 8 for mediastinoscopy and 2-9 for open lymphadenectomy), the number of lymph node stations examined, sensitivity and negative predictive value with a focus on the technique employed (video-assisted vs standard technique) and the surgeon's experience were calculated. Overall sensitivity was 60%, accuracy was 90% and negative predictive value 88%. With the conventional technique, experience alone improved sensitivity from 49 to 57% and it was predominant at the paratracheal right region (from 62 to 82%). But with the video-assisted technique, experienced surgeons rose sensitivity from 57 to 79% in contrast to inexperienced surgeons who lowered sensitivity from 49 to 33%. We found significant differences concerning (i) the total number of specimens taken, (ii) the amount of lymph node stations examined, (iii) the number of specimens taken per lymph node station and (iv) true positive mediastinoscopies. The video-assisted technique can significantly improve the results of mediastinoscopy. A thorough education on the modern video-assisted technique is mandatory for thoracic surgeons until they can fully exhaust its potential.

  12. Breast-conserving radiation therapy using combined electron and intensity-modulated radiotherapy technique

    International Nuclear Information System (INIS)

    Li, J.G.; Williams, S.S.; Goffinet, D.R.; Boer, A.L.; Xing, L.

    2000-01-01

    An electron beam with appropriate energy was combined with four intensity modulated photon beams. The direction of the electron beam was chosen to be tilted 10-20 laterally from the anteroposterior direction. Two of the intensity-modulated photon beams had the same gantry angles as the conventional tangential fields, whereas the other two beams were rotated 15-25' toward the anteroposterior directions from the first two photon beams. An iterative algorithm was developed which optimizes the weight of the electron beam as well as the fluence profiles of the photon beams for a given patient. Two breast cancer patients with early-stage breast tumors were planned with the new technique and the results were compared with those from 3D planning using tangential fields as well as 9-field intensity-modulated radiotherapy (IMRT) techniques. The combined electron and IMRT plans showed better dose conformity to the target with significantly reduced dose to the ipsilateral lung and, in the case of the left-breast patient, reduced dose to the heart, than the tangential field plans. In both the right-sided and left-sided breast plans, the dose to other normal structures was similar to that from conventional plans and was much smaller than that from the 9-field IMRT plans. The optimized electron beam provided between 70 to 80% of the prescribed dose at the depth of maximum dose of the electron beam. The combined electron and IMRT technique showed improvement over the conventional treatment technique using tangential fields with reduced dose to the ipsilateral lung and the heart. The customized beam directions of the four IMRT fields also kept the dose to other critical structures to a minimum. (author)

  13. Effectiveness of different rescanning techniques for scanned proton radiotherapy in lung cancer patients

    Science.gov (United States)

    Engwall, E.; Glimelius, L.; Hynning, E.

    2018-05-01

    Non-small cell lung cancer (NSCLC) is a tumour type thought to be well-suited for proton radiotherapy. However, the lung region poses many problems related to organ motion and can for actively scanned beams induce severe interplay effects. In this study we investigate four mitigating rescanning techniques: (1) volumetric rescanning, (2) layered rescanning, (3) breath-sampled (BS) layered rescanning, and (4) continuous breath-sampled (CBS) layered rescanning. The breath-sampled methods will spread the layer rescans over a full breathing cycle, resulting in an improved averaging effect at the expense of longer treatment times. In CBS, we aim at further improving the averaging by delivering as many rescans as possible within one breathing cycle. The interplay effect was evaluated for 4D robustly optimized treatment plans (with and without rescanning) for seven NSCLC patients in the treatment planning system RayStation. The optimization and final dose calculation used a Monte Carlo dose engine to account for the density heterogeneities in the lung region. A realistic treatment delivery time structure given from the IBA ScanAlgo simulation tool served as basis for the interplay evaluation. Both slow (2.0 s) and fast (0.1 s) energy switching times were simulated. For all seven studied patients, rescanning improves the dose conformity to the target. The general trend is that the breath-sampled techniques are superior to layered and volumetric rescanning with respect to both target coverage and variability in dose to OARs. The spacing between rescans in our breath-sampled techniques is set at planning, based on the average breathing cycle length obtained in conjunction with CT acquisition. For moderately varied breathing cycle lengths between planning and delivery (up to 15%), the breath-sampled techniques still mitigate the interplay effect well. This shows the potential for smooth implementation at the clinic without additional motion monitoring equipment.

  14. SU-F-T-87: Comparison of Advanced Radiotherapy Techniques for Post- Mastectomy Breast Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Heins, D; Zhang, R [Louisiana State University, Baton Rouge, LA (United States); Hogstrom, K; Sanders, M [Mary Bird Perkins Cancer Center, Baton Rouge, LA (United States)

    2016-06-15

    Purpose: To determine if bolus electron conformal therapy (Bolus-ECT) combined with intensity modulated x-ray therapy (IMXT) and flattening filter free volumetric modulated arc therapy (FFF-VMAT (6x and 10x)) can maintain equal or better dose coverage than standard volumetric modulated arc therapy (Std-VMAT) while reducing doses to organs at risk (OARs). Methods: Bolus-ECT with IMXT, FFF-VMAT, and Std-VMAT treatment plans were produced for ten post-mastectomy radiotherapy (PMRT) patients previously treated at our clinic. The treatment plans were created on commercially available treatment planning system (TPS) and all completed treatment plans were reviewed and approved by a radiation oncologist. The plans were evaluated based on planning target volume (PTV) coverage, tumor control probability (TCP), dose homogeneity index (DHI), conformity index (CI), and dose to organs at risk (OAR). Results: All techniques produced clinically acceptable PMRT plans. Overall, Bolus-ECT with IMXT exhibited higher maximum dose compared to all VMAT techniques. Bolus-ECT with IMXT and FFF-VMAT10x had slightly improved TCP over FFF-VMAT6x and Std-VMAT. However, all VMAT techniques showed improved CI and DHI over Bolus-ECT with IMXT. All techniques showed very similar mean lung dose. Bolus-ECT with IMXT exhibited a reduced mean heart dose over Std-VMAT. Both FFF-VMAT techniques had higher mean heart dose compared to Std-VMAT. In addition, Bolus-ECT with IMXT was able to reduce mean dose to the contralateral breast compared to Std-VMAT and both FFF-VMAT techniques had comparable but slightly reduced dose compared to Std-VMAT. Conclusion: This work has shown that Bolus-ECT with IMXT produces clinically acceptable plans while reducing OAR doses. Both FFF-VMAT techniques are comparable to Std-VMAT with slight improvements. Even though all VMAT techniques produce more homogenous and conformal dose distributions, Bolus-ECT with IMXT is a viable option for treating post-mastectomy patients

  15. Validation of a cylindrical phantom for verification of radiotherapy treatments in head and neck with special techniques

    International Nuclear Information System (INIS)

    Vargas, Nicolas M.; Garcia, Marcia; Piriz, Gustavo; Perez, Niurka

    2011-01-01

    Verification of radiotherapy treatments in head and neck requires, among other things, small volume chambers and a phantom to reproduce the geometry and density of the anatomical structure. New documents from the ICRU (International Commission on Radiation Units and Measurements), Report 83, established the need for quality control in radiotherapy with special techniques such as IMRT (intensity-modulated radiation therapy). In this study, we built a cylindrical acrylic phantom with standing water, containing seven measuring points in the transverse plane and free location (0-20 cm) in the longitudinal plane. These points of measurement are constituted by cavities for the accommodation of the ionization chamber of 7 mm of mayor diameter (semi flex, pinpoint with build cup). The results of the phantom validation yielded percentage differences less than 1% in fixed beams and less than 2.5% in arc therapy for TPS Eclipse calculation. The preparation of this phantom, particularly made to verify the head and neck treatments, was simple and reliable for checking the dose in radiotherapy with fixed beams and/or special techniques such as arc therapy or IMRT, so that will be sent to various radiotherapy centers in the country for dosimetric verification in such treatments. (author)

  16. Validation of a cylindrical phantom for verification of radiotherapy treatments in head and neck with special techniques

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, Nicolas M.; Garcia, Marcia, E-mail: nimoralesv@gmail.com [Universidad de La Frontera, Temuco (Chile). Dept. de Ciencias Fisicas; Piriz, Gustavo [Instituto Nacional del Cancer, Santiago (Chile). Fisica Medica; Perez, Niurka [Instituto de Salud Publica, Santiago (Chile). QA Radioterapia. Inst. de Salud Publica

    2011-07-01

    Verification of radiotherapy treatments in head and neck requires, among other things, small volume chambers and a phantom to reproduce the geometry and density of the anatomical structure. New documents from the ICRU (International Commission on Radiation Units and Measurements), Report 83, established the need for quality control in radiotherapy with special techniques such as IMRT (intensity-modulated radiation therapy). In this study, we built a cylindrical acrylic phantom with standing water, containing seven measuring points in the transverse plane and free location (0-20 cm) in the longitudinal plane. These points of measurement are constituted by cavities for the accommodation of the ionization chamber of 7 mm of mayor diameter (semi flex, pinpoint with build cup). The results of the phantom validation yielded percentage differences less than 1% in fixed beams and less than 2.5% in arc therapy for TPS Eclipse calculation. The preparation of this phantom, particularly made to verify the head and neck treatments, was simple and reliable for checking the dose in radiotherapy with fixed beams and/or special techniques such as arc therapy or IMRT, so that will be sent to various radiotherapy centers in the country for dosimetric verification in such treatments. (author)

  17. Radiotherapy in bladder cancer

    International Nuclear Information System (INIS)

    Rozan, R.

    1992-01-01

    In 1992, the problem of the vesical radiotherapy is not resolved. The author presents the situation and the different techniques of radiotherapy in bladder cancers: external radiotherapy, only and associated with surgery, interstitial curietherapy and non-classical techniques as per operative radiotherapy, neutron therapy and concurrent radiotherapy with chemotherapy. In order to compare their efficiency, the five-year survival are given in all cases.(10 tabs)

  18. Does obesity hinder radiotherapy in endometrial cancer patients? The implementation of new techniques in adjuvant radiotherapy – focus on obese patients

    Directory of Open Access Journals (Sweden)

    Małgorzata Moszyńska-Zielińska

    2014-05-01

    Full Text Available The increasing incidence of obesity in Poland and its relation to endometrioid endometrial cancer (EEC is resulting in the increasing necessity of treating obese women. Treatment of an overweight patient with EEC may impede not only the surgical procedures but also radiotherapy, especially external beam radiotherapy (EBRT. The problems arise both during treatment planning and when delivering each fraction due to the difficulty of positioning such a patient – it implies the danger of underdosing targets and overdosing organs at risk. Willingness to use dynamic techniques in radiation oncology has increased for patients with EEC, even those who are obese. During EBRT careful daily verification is necessary for both safety and treatment accuracy. The most accurate method of verification is cone beam computed tomography (CBCT with soft tissue assessment, although it is time consuming and often requires a radiation oncologist. In order to improve the quality of such treatment, the authors present the practical aspects of planning and treatment itself by means of dynamic techniques in EBRT. The authors indicate the advantages and disadvantages of different types of on-board imaging (OBI verification images. Considering the scanty amount of literature in this field, it is necessary to conduct further research in order to highlight proper planning and treatment of obese endometrial cancer patients. The review of the literature shows that all centres that wish to use EBRT for gynaecological tumours should develop their own protocols on qualification, planning the treatment and methods of verifying the patients’ positioning.

  19. A Dosimetric Comparison of Breast Radiotherapy Techniques to Treat Locoregional Lymph Nodes Including the Internal Mammary Chain.

    Science.gov (United States)

    Ranger, A; Dunlop, A; Hutchinson, K; Convery, H; Maclennan, M K; Chantler, H; Twyman, N; Rose, C; McQuaid, D; Amos, R A; Griffin, C; deSouza, N M; Donovan, E; Harris, E; Coles, C E; Kirby, A

    2018-06-01

    Radiotherapy target volumes in early breast cancer treatment increasingly include the internal mammary chain (IMC). In order to maximise survival benefits of IMC radiotherapy, doses to the heart and lung should be minimised. This dosimetry study compared the ability of three-dimensional conformal radiotherapy, arc therapy and proton beam therapy (PBT) techniques with and without breath-hold to achieve target volume constraints while minimising dose to organs at risk (OARs). In 14 patients' datasets, seven IMC radiotherapy techniques were compared: wide tangent (WT) three-dimensional conformal radiotherapy, volumetric-modulated arc therapy (VMAT) and PBT, each in voluntary deep inspiratory breath-hold (vDIBH) and free breathing (FB), and tomotherapy in FB only. Target volume coverage and OAR doses were measured for each technique. These were compared using a one-way ANOVA with all pairwise comparisons tested using Bonferroni's multiple comparisons test, with adjusted P-values ≤ 0.05 indicating statistical significance. One hundred per cent of WT(vDIBH), 43% of WT(FB), 100% of VMAT(vDIBH), 86% of VMAT(FB), 100% of tomotherapy FB and 100% of PBT plans in vDIBH and FB passed all mandatory constraints. However, coverage of the IMC with 90% of the prescribed dose was significantly better than all other techniques using VMAT(vDIBH), PBT(vDIBH) and PBT(FB) (mean IMC coverage ± 1 standard deviation = 96.0% ± 4.3, 99.8% ± 0.3 and 99.0% ± 0.2, respectively). The mean heart dose was significantly reduced in vDIBH compared with FB for both the WT (P FB). Simple WT radiotherapy delivered in vDIBH achieves satisfactory coverage of the IMC while meeting heart and lung dose constraints. However, where higher isodose coverage is required, VMAT(vDIBH) is the optimal photon technique. The lowest OAR doses are achieved by PBT, in which the use of vDIBH does not improve dose statistics. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

  20. Hypofractionation does not increase radiation pneumonitis risk with modern conformal radiation delivery techniques

    DEFF Research Database (Denmark)

    Vogelius, Ivan R; Westerly, David C; Cannon, George M

    2010-01-01

    To study the interaction between radiation dose distribution and hypofractionated radiotherapy with respect to the risk of radiation pneumonitis (RP) estimated from normal tissue complication probability (NTCP) models.......To study the interaction between radiation dose distribution and hypofractionated radiotherapy with respect to the risk of radiation pneumonitis (RP) estimated from normal tissue complication probability (NTCP) models....

  1. Studies Regarding Design and Optimization of Mechanisms Using Modern Techniques of CAD and CAE

    Directory of Open Access Journals (Sweden)

    Marius Tufoi

    2010-01-01

    Full Text Available The paper presents applications of modern techniques of CAD (Computer Aided Design and CAE (Computer Aided Engineering to design and optimize the mechanisms used in mechanical engineering. The use exemplification of these techniques was achieved by designing and optimizing parts of a drawing installation for horizontal continuous casting of metals. By applying these design methods and using finite element method at simulations on designed mechanisms results a number of advantages over traditional methods of drawing and design: speed in drawing, design and optimization of parts and mechanisms, kinematic analysis option, kinetostatic and dynamic through simulation, without requiring physical realization of the part or mechanism, the determination by finite element method of tension, elongations, travel and safety factor and the possibility of optimization for these sizes to ensure the mechanical strength of each piece separately. Achieving these studies was possible using SolidWorks 2009 software suite.

  2. Advantages and disadvantages of using non-coplanar techniques in radiotherapy of the abdomen formed 3D

    International Nuclear Information System (INIS)

    Urena Llinares, A.; Castro Ramirez, I.; Iborra Oquendo, M. A; Quinones Rodriguez, L. A.; Angulo Pain, E.

    2011-01-01

    3D Radiotherapy locations abdomen, especially in pancreas and stomach cancers is often extremely difficult if we are to meet the dose constraints to organs at risk due to proximity and many of these (liver, kidneys, intestines, lungs, bone. ..). Of these, the most critical are the kidneys, which also present values of tolerance, in most cases difficult to meet. This is done in our hospital are using non-coplanar techniques performing well both as coating PTV dose to both kidneys.

  3. [Novel irradiation techniques in the treatment of solid tumours. Radiotherapy for metastases].

    Science.gov (United States)

    Mayer, Arpád; Póti, Zsuzsa

    2014-02-23

    Novel developments in percutaneous radiotherapy, such as positron emission tomography/computed tomography, adaptive radiation planning, intensity modulation radiotherapy and intensity modulated arc therapy (RapidArc), as well as the newer generation of image control (cone-beam computed tomography) and image guided radiotherapy ensure increased dosages of planning target volume and clinical target volume of solid tumours without damaging surrounding tissues and providing maximal protection. By raising the dosages of planned target volume and clinical target volume, these novel technical developments have created new indications in the treatment of solid tumours. With the aid of the cone-beam computed tomography and image guided radiotherapy the organ metastasis (lung, liver, spinal cord) and the primary tumour can be treated safety and effectively. Hypofractionation, dose escalation and the use of stereotactic devices can probably decrease radiation damage. The authors review the most common forms of evidence-based fractionation schemes used in irradiation therapy.

  4. Technique for axillary radiotherapy using computer-assisted planning for high-risk skin cancerΤ

    International Nuclear Information System (INIS)

    Fogarty, G.B.; Martin, J.M.; Fay, M.; Ainslie J; Cassumbhoy, R.

    2007-01-01

    High-risk skin cancer arising on the upper limb or trunk can cause axillary nodal metastases. Previous studies have shown that axillary radiotherapy improves regional control. There is little published work on technique. Technique standardization is important in quality assurance and comparison of results especially for trials. Our technique, planned with CT assistance, is presented. To assess efficacy, an audit of patients treated in our institution over a 15-month period was conducted. Of 24 patients treated, 13 were treated with radical intent, 11 with this technique. With a follow up of over 2 years, the technique had more than a 90% (10/11) regional control in this radical group. Both of the radical patients who were not treated according to the technique had regional failure. One case of late toxicity was found, of asymptomatic lymphoedema in a radically treated patient. This technique for axillary radiotherapy for regional control of skin cancer is acceptable in terms of disease control and toxicity as validated by audit at 2 years

  5. Evaluation of conformal radiotherapy techniques through physics and biologic criteria; Avaliacao de tecnicas radioterapicas conformacionais utilizando criterios fisicos e biologicos

    Energy Technology Data Exchange (ETDEWEB)

    Bloch, Jonatas Carrero

    2012-07-01

    In the fight against cancer, different irradiation techniques have been developed based on technological advances and aiming to optimize the elimination of tumor cells with the lowest damage to healthy tissues. The radiotherapy planning goal is to establish irradiation technical parameters in order to achieve the prescribed dose distribution over the treatment volumes. While dose prescription is based on radiosensitivity of the irradiated tissues, the physical calculations on treatment planning take into account dosimetric parameters related to the radiation beam and the physical characteristics of the irradiated tissues. To incorporate tissue's radiosensitivity into radiotherapy planning calculations can help particularize treatments and establish criteria to compare and elect radiation techniques, contributing to the tumor control and the success of the treatment. Accordingly, biological models of cellular response to radiation have to be well established. This work aimed to study the applicability of using biological models in radiotherapy planning calculations to aid evaluating radiotherapy techniques. Tumor control probability (TCP) was studied for two formulations of the linear-quadratic model, with and without repopulation, as a function of planning parameters, as dose per fraction, and of radiobiological parameters, as the α/β ratio. Besides, the usage of biological criteria to compare radiotherapy techniques was tested using a prostate planning simulated with Monte Carlo code PENELOPE. Afterwards, prostate planning for five patients from the Hospital das Clinicas da Faculdade de Medicina de Ribeirao Preto, USP, using three different techniques were compared using the tumor control probability. In that order, dose matrices from the XiO treatment planning system were converted to TCP distributions and TCP-volume histograms. The studies performed allow the conclusions that radiobiological parameters can significantly influence tumor control

  6. Conventional radiotherapy of localized right side breast cancer after radical mastectomy: development of innovative “field in field” technique

    Directory of Open Access Journals (Sweden)

    Goran Marošević

    2011-12-01

    Full Text Available Introduction: The aim of this paper is to study the distribution of the therapy dosage applied by a modified conventional “field in field” technique and compare it to the distribution of the dosage applied by the standard conventional technique.Methods: The study included ten patients with right side breast cancer, after they were exposed to radical mastectomy and chemotherapy. Radiotherapy dosage of TD 50 Gy in 25 fractions was applied to the anterolateral side of the right thoracic wall, with two opposite conventional tangential fields by the linear accelerator Elekta Synergy and the energy of 6 megavolts (MV. A delineation of the target volume (CTV – Clinical Target Volume was done within conventional fields. At the XiO system for planning we included additional fields within the existing conventional fields, which was the so called “field in field” technique. On the basis of CTV the Dose Volume  Histogram (DVH was calculated for conventional and “field in field” plans. VD90%, VD95%, VD107%, VD115%, CI and HI were calculated for both techniques. Means were pared with the paired Student's t-test. The results were considered significantly different if p<0.05.Results: VD90% and VD 95% were significantly higher for the “field in field” technique. Therefore, CI also favored the “field in field” technique (p=0.02. There was no difference in VD107% and VD115% between the compared groups. Consequently, there was no statistically significant difference in HI (1.13±0.03 vs.1.13±0.03, p=0.06.Conclusion: Conventional postoperative radiotherapy of localized right side breast cancer by “field in field” technique provides excellent coverage of the target volume by radiotherapy isodose.

  7. Recent advances in the instrumental techniques for the analysis of modern materials (II)

    International Nuclear Information System (INIS)

    Ahmed, M.

    1990-01-01

    Inductively Coupled Plasma Mass Spectrometry ICP-MS a logical development of equally established sister technique of ICP-AEA discussed in part-1 of this series of article on modern analytical techniques. The rapid adaptation of argon plasma as ion source for time of flight quadrupole mass analyser has led to the development of truly integrated instrumental technique for analysis of solutions and slurries. The powerful combination with laser ablation device has made the direct analysis of geological, geochemical and other complex conducting and non conducting samples possible in days rather months at sub ppm levels. Parallel development in computer hardware and software has made the instrumental optimization easy enabling the generation of meaningful analytical data a matter of routine. The limitations imposed by spectroscopic and non restricted the variety of matrices and materials covered by ICP-MS of LA-ICP-MS. The technique has provided it formidable analytical power in wide areas of industrial environmental, social, biological and break through advanced materials used in space mass communication, transportation and general areas of advanced analytical chemistry. It is expected that in combination with other instrumental methods as HPLC, ETC, ion chromatography. ICP-MS shall continue to dominate well into the 21st century. (author)

  8. A simple technique for treating age-related macular degeneration with external beam radiotherapy

    International Nuclear Information System (INIS)

    Roos, Daniel E.; Francis, J. Winston; Newnham, W. John

    1999-01-01

    Purpose: To develop a simple external beam photon radiotherapy technique to treat age-related macular degeneration without the need for simulation, planning computed tomography (CT) or computer dosimetry. Methods and Materials: The goal was to enable the treatment to be set up reliably on the treatment machine on Day 1 with the patient supine in a head cast without any prior planning. Using measurements of ocular globe topography from Karlsson et al. (Int J Radiat Oncol Biol Phys 1996; 33: 705-712), we chose a point 1.5 cm behind the anterior surface of the upper eyelid (ASUE) as the isocentre of a half-beam, blocked, 5.0 x 3.0-cm, angled lateral field to treat the involved eye. This would position the isocentre about 0.5 cm behind the posterior surface of the lens, and a little over 1 cm in front of the macula, according to Karlsson et al. The setup requires initial adjustment of the gantry from horizontal (to account for any asymmetry of position of the eyes), then angling 15 deg. posteriorly to avoid the contralateral eye. Finally, the couch is raised to position the isocentre 1.5 cm behind the ASUE. Results: To verify the applicability of the technique, we performed CT and computer dosimetry on the first 11 eyes so treated. Our CT measurements were in good agreement with Karlsson et al. The lens dose was < 5% and the macula was within the 95% isodose curve in each case (6-MV linac). Treatment setup time is approximately 10 min each day. The 11 patients were treated with 5 x 2.00 Gy (2 patients) or 5 x 3.00 Gy (9 patients), and subjective response on follow-up over 1 to 12 months (median 4 months) was comparable to previously reported results, with no significant acute side effects. Conclusion: Our technique is easy to set up and reliably treats the macula, with sparing of the lens and contralateral eye. It enables treatment to commence rapidly and cost-effectively without the need for simulation or CT computer planning

  9. EDITORIAL: International Workshop on Monte Carlo Techniques in Radiotherapy Delivery and Verification

    Science.gov (United States)

    Verhaegen, Frank; Seuntjens, Jan

    2008-03-01

    Monte Carlo particle transport techniques offer exciting tools for radiotherapy research, where they play an increasingly important role. Topics of research related to clinical applications range from treatment planning, motion and registration studies, brachytherapy, verification imaging and dosimetry. The International Workshop on Monte Carlo Techniques in Radiotherapy Delivery and Verification took place in a hotel in Montreal in French Canada, from 29 May-1 June 2007, and was the third workshop to be held on a related topic, which now seems to have become a tri-annual event. About one hundred workers from many different countries participated in the four-day meeting. Seventeen experts in the field were invited to review topics and present their latest work. About half of the audience was made up by young graduate students. In a very full program, 57 papers were presented and 10 posters were on display during most of the meeting. On the evening of the third day a boat trip around the island of Montreal allowed participants to enjoy the city views, and to sample the local cuisine. The topics covered at the workshop included the latest developments in the most popular Monte Carlo transport algorithms, fast Monte Carlo, statistical issues, source modeling, MC treatment planning, modeling of imaging devices for treatment verification, registration and deformation of images and a sizeable number of contributions on brachytherapy. In this volume you will find 27 short papers resulting from the workshop on a variety of topics, some of them on very new stuff such as graphics processing units for fast computing, PET modeling, dual-energy CT, calculations in dynamic phantoms, tomotherapy devices, . . . . We acknowledge the financial support of the National Cancer Institute of Canada, the Institute of Cancer Research of the Canadian Institutes of Health Research, the Association Québécoise des Physicien(ne)s Médicaux Clinique, the Institute of Physics, and Medical

  10. Introduction. [usefulness of modern remote sensing techniques for studying components of California water resources

    Science.gov (United States)

    Colwell, R. N.

    1973-01-01

    Since May 1970, personnel on several campuses of the University of California have been conducting investigations which seek to determine the usefulness of modern remote sensing techniques for studying various components of California's earth resources complex. Emphasis has been given to California's water resources as exemplified by the Feather River project and other aspects of the California Water Plan. This study is designed to consider in detail the supply, demand, and impact relationships. The specific geographic areas studied are the Feather River drainage in northern California, the Chino-Riverside Basin and Imperial Valley areas in southern California, and selected portions of the west side of San Joaquin Valley in central California. An analysis is also given on how an effective benefit-cost study of remote sensing in relation to California's water resources might best be made.

  11. The use of modern measurement techniques for designing pro ecological constructions

    Science.gov (United States)

    Wieczorowski, Michał; Gapiński, Bartosz; Szymański, Maciej; Rękas, Artur

    2017-10-01

    In the paper some possibilities of application modern length and angle metrology techniques to design constructions that support ecology were presented. The paper is based on a project where a lighter bus and train car seat was developed. Different options were presented including static and dynamic photogrammetry, computed tomography and thermography. Research related with dynamic behaviour of designed structures gave input to determine deformation of a seat and passengers sitting on it during communication accidents. Works connected to strength of construction elements made it possible to optimize its dimensions maintaining proper durability. Metrological actions taken in relation to production machines and equipment enabled to better recognize phenomena that take place during manufacturing process and to correct its parameters, what in turns also contributed to slim down the construction.

  12. Megadolichobasilarartery as a rare cause of a hydrocephalus internus -synopsis of modern imaging techniques

    International Nuclear Information System (INIS)

    Lemke, A.J.; Sander, B.; Benndorf, G.; Balzer, J.; Boerschel, M.F.; Hosten, N.; Sprung, C.; Ricke, J.; Felix, R.; Lanksch, W.R.

    1995-01-01

    Megadolichobasilarartery (MDB), i.e. the widened, elongated and tortuous course of the basilar artery, has been the topic of numerous publications; about 350 cases have been reported world-wide. It can cause many symptoms; isolated or combined cranial nerve lesions and ischemic or hemorrhagic changes are the most frequent. A hydrocephalus internus is a rare occurrence and many patients do not exhibit any symptoms. To date, angiography, computed tomography, and to an increasing extent magnetic resonance imaging (MRI) are the principal methods for diagnosis of MDB. Angiographic-like representations with CT and MRI are further developments which represent an alternative to angiography. With the help of special MRI sequences, furthermore, non-invasive CSF flow measurements for the etiologic evaluation of a hydrocephalus can be performed. For the example of a patient with MDB and hydrocephalus internus, the possibilities of modern imaging techniques are presented and discussed. (orig.) [de

  13. A systematic review of applying modern software engineering techniques to developing robotic systems

    Directory of Open Access Journals (Sweden)

    Claudia Pons

    2012-01-01

    Full Text Available Robots have become collaborators in our daily life. While robotic systems become more and more complex, the need to engineer their software development grows as well. The traditional approaches used in developing these software systems are reaching their limits; currently used methodologies and tools fall short of addressing the needs of such complex software development. Separating robotics’ knowledge from short-cycled implementation technologies is essential to foster reuse and maintenance. This paper presents a systematic review (SLR of the current use of modern software engineering techniques for developing robotic software systems and their actual automation level. The survey was aimed at summarizing existing evidence concerning applying such technologies to the field of robotic systems to identify any gaps in current research to suggest areas for further investigation and provide a background for positioning new research activities.

  14. Breathing adapted radiotherapy for breast cancer: comparison of free breathing gating with the breath-hold technique

    DEFF Research Database (Denmark)

    Korreman, Stine Sofia; Pedersen, Anders N; Nøttrup, Trine Jakobi

    2005-01-01

    BACKGROUND AND PURPOSE: Adjuvant radiotherapy after breast-conserving surgery for breast cancer implies a risk of late cardiac and pulmonary toxicity. This is the first study to evaluate cardiopulmonary dose sparing of breathing adapted radiotherapy (BART) using free breathing gating......, and to compare this respiratory technique with voluntary breath-hold. PATIENTS AND METHODS: 17 patients were CT-scanned during non-coached breathing manoeuvre including free breathing (FB), end-inspiration gating (IG), end-expiration gating (EG), deep inspiration breath-hold (DIBH) and end-expiration breath......-hold (EBH). The Varian Real-time Position Management system (RPM) was used to monitor respiratory movement and to gate the scanner. For each breathing phase, a population based internal margin (IM) was estimated based on average chest wall excursion, and incorporated into an individually optimised three...

  15. Classical tandem-source dwelling covering the entire uterus. Essential in modern intracavitary radiotherapy for cervical cancer?

    International Nuclear Information System (INIS)

    Ohara, Kiyoshi; Nemoto, Keiko; Ohnishi, Kayoko; Hashimoto, Takayuki; Fukumitsu, Nobuyoshi; Hata, Masaharu; Sugahara, Shinji; Tokuuye, Koichi; Akine, Yasuyuki

    2007-01-01

    We investigated whether conventional tandem-source dwelling to cover the entire uterus, classically regarded as the target volume, is necessary in modem intracavitary radiotherapy (ICRT) for cervical cancer. The study included 95 cervical squamous cell carcinoma patients treated by high-dose-rate ICRT (point A dose was 6.0 Gy, with three to five insertions per patient) after external beam radiotherapy (EBRT), with central pelvic doses of 12-50 Gy. The tandem-source dwell length was adjusted to the target volume specified by magnetic resonance (MR) imaging. A tandem applicator was inserted as far as the uterine fundus in accordance with the post-EBRT MR-assessed cavity length. The pre-EBRT MR-specified target volume was used for the dwell-length adjustment. The safety of the dwell-length adjustment was assessed in terms of treatment failure. The dwell-length adjustment was made in 248 of 366 total insertions with a dwell-length reduction of 5-55 mm (median 15 mm) at the corpus. Pelvic failure was identified in 22 patients with a 2-year pelvic disease-free survival rate of 75.6% but without evidence of failure at dwelling-skipped corpuses. Given after pelvic EBRT and ICRT of full-length dwelling in part, which may have eradicated possible subclinical extension, adjustment of the tandem-source dwell length to the MR-specified target volume appeared to be safe. (author)

  16. TA3 - Dosimetry and instrumentation supply of the M-Fish technique to the Fish-3 painting technique for analysing translocations: A radiotherapy-treated patient study

    International Nuclear Information System (INIS)

    Pouzoulet, F.; Roch-Lefevre, S.; Giraudet, A.L.; Vaurijoux, A.; Voisin, P.A.; Buard, V.; Delbos, M.; Voisin, Ph.; Roy, L.; Bourhis, J.

    2006-01-01

    Purpose: Currently, the chromosome translocation study is the best method to estimate the dose of an old radiation exposure. Fluorescent In Situ Hybridization (F.I.S.H.) technique allows an easy detection of this kind of aberrations. However, as only a few number of chromosomes is usually painted, some bias could skew the result. To evaluate the advantage of using full genome staining (M-F.I.S.H. technique) compared with three chromosomes labelling (F.I.S.H.-3 painting), we compared translocation yields in radiotherapy treated patients. Methods: Chromosome aberration analyses were performed on peripheral blood lymphocyte cultures of two patients treated for a throat cancer by radiotherapy. Blood samples were obtained, before, along the treatment and six or four months later. For each sample, a dicentrics analysis was performed together with translocation analysis either with F.I.S.H.-3 painting or M-F.I.S.H.. Results: By confronting results from the F.I.S.H.-3 painting technique and the M-F.I.S.H. technique, significant differences were revealed. The translocations yield seemed to be stable with the F.I.S.H.-3 painting technique whereas it is not the case with the M-F.I.S.H. technique. This difference in results was explained by the bias induced by F.I.S.H.-3 Painting technique in the visualisation of complex aberrations. Furthermore, we found the presence of a clone bearing a translocation involving a painted chromosome. Conclusions: According to the potential bias of F.I.S.H.-3 painting on translocations study, the M-F.I.S.H. technique should provide more precise and reproducible results. Because of its more difficult implement, it seems hardly applicable to retrospective dosimetry instead of F.I.S.H.-3 painting technique. (authors)

  17. TA3 - Dosimetry and instrumentation supply of the M-Fish technique to the Fish-3 painting technique for analysing translocations: A radiotherapy-treated patient study

    Energy Technology Data Exchange (ETDEWEB)

    Pouzoulet, F.; Roch-Lefevre, S.; Giraudet, A.L.; Vaurijoux, A.; Voisin, P.A.; Buard, V.; Delbos, M.; Voisin, Ph.; Roy, L. [Institut de Radioprotection et de Surete Nucleaire, Lab. de Dosimetrie Biologique, 92 - Fontenay aux Roses (France); Bourhis, J. [Laboratoire UPRES EA 27-10, Radiosensibilite des Tumeurs et Tissus sains, PR1, 94 - Villejuif (France)

    2006-07-01

    Purpose: Currently, the chromosome translocation study is the best method to estimate the dose of an old radiation exposure. Fluorescent In Situ Hybridization (F.I.S.H.) technique allows an easy detection of this kind of aberrations. However, as only a few number of chromosomes is usually painted, some bias could skew the result. To evaluate the advantage of using full genome staining (M-F.I.S.H. technique) compared with three chromosomes labelling (F.I.S.H.-3 painting), we compared translocation yields in radiotherapy treated patients. Methods: Chromosome aberration analyses were performed on peripheral blood lymphocyte cultures of two patients treated for a throat cancer by radiotherapy. Blood samples were obtained, before, along the treatment and six or four months later. For each sample, a dicentrics analysis was performed together with translocation analysis either with F.I.S.H.-3 painting or M-F.I.S.H.. Results: By confronting results from the F.I.S.H.-3 painting technique and the M-F.I.S.H. technique, significant differences were revealed. The translocations yield seemed to be stable with the F.I.S.H.-3 painting technique whereas it is not the case with the M-F.I.S.H. technique. This difference in results was explained by the bias induced by F.I.S.H.-3 Painting technique in the visualisation of complex aberrations. Furthermore, we found the presence of a clone bearing a translocation involving a painted chromosome. Conclusions: According to the potential bias of F.I.S.H.-3 painting on translocations study, the M-F.I.S.H. technique should provide more precise and reproducible results. Because of its more difficult implement, it seems hardly applicable to retrospective dosimetry instead of F.I.S.H.-3 painting technique. (authors)

  18. An integrated spectroscopic approach for the non-invasive study of modern art materials and techniques

    Science.gov (United States)

    Rosi, F.; Miliani, C.; Clementi, C.; Kahrim, K.; Presciutti, F.; Vagnini, M.; Manuali, V.; Daveri, A.; Cartechini, L.; Brunetti, B. G.; Sgamellotti, A.

    2010-09-01

    A non-invasive study has been carried out on 18 paintings by Alberto Burri (1915-1995), one of Italy’s most important contemporary painters. The study aims to demonstrate the appropriate and suitable use of portable non-invasive instrumentation for the characterization of materials and techniques found in works dating from 1948 to 1975 belonging to the Albizzini Collection. Sampling of any kind has been forbidden, in order to maintain the integrity of the paintings. Furthermore, the material heterogeneity of each single artwork could potentially result in a poorly representative sampling campaign. Therefore, a non-invasive and in situ analytical approach has been deemed mandatory, notwithstanding the complexity of modern materials and challenging data interpretation. It is the non-invasive nature of the study that has allowed for the acquisition of vast spectral data (a total of about 650 spectra including XRF, mid and near FTIR, micro-Raman and UV-vis absorption and emission spectroscopies). In order to better handle and to extrapolate the most meaningful information from these data, a statistical multivariate analysis, namely principal component analysis (PCA), has been applied to the spectral results. In particular, the possibility of combining elemental and molecular information has been explored by uniting XRF and infrared spectra in one PCA dataset. The combination of complementary spectroscopic techniques has allowed for the characterization of both inorganic and organic pigments, extenders, fillers, and binders employed by Alberto Burri.

  19. The design of a turboshaft speed governor using modern control techniques

    Science.gov (United States)

    Delosreyes, G.; Gouchoe, D. R.

    1986-01-01

    The objectives of this program were: to verify the model of off schedule compressor variable geometry in the T700 turboshaft engine nonlinear model; to evaluate the use of the pseudo-random binary noise (PRBN) technique for obtaining engine frequency response data; and to design a high performance power turbine speed governor using modern control methods. Reduction of T700 engine test data generated at NASA-Lewis indicated that the off schedule variable geometry effects were accurate as modeled. Analysis also showed that the PRBN technique combined with the maximum likelihood model identification method produced a Bode frequency response that was as accurate as the response obtained from standard sinewave testing methods. The frequency response verified the accuracy of linear models consisting of engine partial derivatives and used for design. A power turbine governor was designed using the Linear Quadratic Regulator (LQR) method of full state feedback control. A Kalman filter observer was used to estimate helicopter main rotor blade velocity. Compared to the baseline T700 power turbine speed governor, the LQR governor reduced droop up to 25 percent for a 490 shaft horsepower transient in 0.1 sec simulating a wind gust, and up to 85 percent for a 700 shaft horsepower transient in 0.5 sec simulating a large collective pitch angle transient.

  20. Film techniques in radiotherapy for treatment verification, determination of patient exit dose, and detection of localization error

    International Nuclear Information System (INIS)

    Haus, A.G.; Marks, J.E.

    1974-01-01

    In patient radiation therapy, it is important to know that the diseased area is included in the treatment field and that normal anatomy is properly shielded or excluded. Since 1969, a film technique developed for imaging of the complete patient radiation exposure has been applied for treatment verification and for the detection and evaluation of localization errors that may occur during treatment. The technique basically consists of placing a film under the patient during the entire radiation exposure. This film should have proper sensitivity and contrast in the exit dose exposure range encountered in radiotherapy. In this communication, we describe how various exit doses fit the characteristic curve of the film; examples of films exposed to various exit doses; the technique for using the film to determine the spatial distribution of the absorbed exit dose; and types of errors commonly detected. Results are presented illustrating that, as the frequency of use of this film technique is increased, localization error is reduced significantly

  1. New 2-D dosimetric technique for radiotherapy based on planar thermoluminescent detectors

    International Nuclear Information System (INIS)

    Olko, P.; Marczewska, B.; Czopyk, L.; Czermak, M. A.; Klosowski, M.; Waligorski, M. P. R.

    2006-01-01

    At the Inst. of Nuclear Physics of the Polish Academy of Sciences (IFJ) in Krakow, a two-dimensional (2-D) thermoluminescence (TL) dosimetry system was developed within the MAESTRO (Methods and Advanced Equipment for Simulation and Treatment in Radio-Oncology) 6 Framework Programme and tested by evaluating 2-D dose distributions around radioactive sources. A thermoluminescent detector (TLD) foil was developed, of thickness 0.3 mm and diameter 60 mm, containing a mixture of highly sensitive LiF:Mg,Cu,P powder and Ethylene Tetrafluoroethylene (ETFE) polymer. Foil detectors were irradiated with 226 Ra brachytherapy sources and a 90 Sr/ 90 Y source. 2-D dose distributions were evaluated using a prototype planar (diameter 60 mm) reader, equipped with a 12 bit Charge Coupled Devices (CCD) PCO AG camera, with a resolution of 640 x 480 pixels. The new detectors, showing a spatial resolution better than 0.5 mm and a measurable dose range typical for radiotherapy, can find many applications in clinical dosimetry. Another technology applicable to clinical dosimetry, also developed at IFJ, is the Si microstrip detector of size 95 x 95 mm 2 , which may be used to evaluate the dose distribution with a spatial resolution of 120 μm along one direction, in real-time mode. The microstrip and TLD technology will be further improved, especially to develop detectors of larger area, and to make them applicable to some advanced radiotherapy modalities, such as intensity modulated radiotherapy (IMRT) or proton radiotherapy. (authors)

  2. Whole brain radiotherapy for brain metastases: The technique of irradiation influences the dose to parotid glands

    International Nuclear Information System (INIS)

    Loos, G.; Paulon, R.; Verrelle, P.; Lapeyre, M.

    2012-01-01

    In the treatment of brain metastases, whole brain radiotherapy can be carried out according two distinct methods: one using multi-leaf collimator for field shaping and protection of organs at risk, and a second one is to make a rotation of the field to avoid the eyes. The aim of the study was to compare for 10 patients the dose distributions at organs at risk for each method. Patients received 30 Gy in 10 fractions. Except for parotid glands, the dose received by organs at risk and the planning target volume was the same with each method. For whole brain radiotherapy, excluding the cisterna cerebellomedullaris, the mean parotid dose was 9.63 Gy using the multi-leaf collimator versus 12.32 Gy using the field rotation (P = 0.04). For whole brain radiotherapy including the cisterna cerebellomedullaris, the mean parotid dose was 11.12 Gy using the multi-leaf collimator versus 20.06 Gy using field rotation (P < 0.001). Using the multi-leaf collimator seems recommended for whole brain radiotherapy, to reduce the dose to the parotids. (authors)

  3. Hippocampal sparing radiotherapy for pediatric medulloblastoma: impact of treatment margins and treatment technique

    DEFF Research Database (Denmark)

    Brodin, N. Patrik; af Rosenschold, Per Munck; Blomstrand, Malin

    2014-01-01

    BackgroundWe investigated how varying the treatment margin and applying hippocampal sparing and proton therapy impact the risk of neurocognitive impairment in pediatric medulloblastoma patients compared with current standard 3D conformal radiotherapy.MethodsWe included 17 pediatric medulloblastoma...

  4. Understanding seafloor morphology using remote high frequency acoustic methods: An appraisal to modern techniques and its effectiveness

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B.

    Content-Type text/plain; charset=UTF-8 179 Understanding seafloor morphology using remote high frequency acoustic methods: an appraisal to modern techniques and its effectiveness Bishwajit Chakraborty National institute of Oceanography.... The two third of the earth surface i.e. 362 million square km (70 %) is covered by the ocean. In order to understand the seafloor various methods like: application of remote acoustic techniques, seafloor photographic and geological sampling techniques...

  5. Hypofractionated Accelerated Radiotherapy Using Concomitant Intensity-Modulated Radiotherapy Boost Technique for Localized High-Risk Prostate Cancer: Acute Toxicity Results

    International Nuclear Information System (INIS)

    Lim, Tee S.; Cheung, Patrick; Loblaw, D. Andrew; Morton, Gerard; Sixel, Katharina E.; Pang, Geordi; Basran, Parminder; Zhang Liying; Tirona, Romeo; Szumacher, Ewa; Danjoux, Cyril; Choo, Richard; Thomas, Gillian

    2008-01-01

    Purpose: To evaluate the acute toxicities of hypofractionated accelerated radiotherapy (RT) using a concomitant intensity-modulated RT boost in conjunction with elective pelvic nodal irradiation for high-risk prostate cancer. Methods and Materials: This report focused on 66 patients entered into this prospective Phase I study. The eligible patients had clinically localized prostate cancer with at least one of the following high-risk features (Stage T3, Gleason score ≥8, or prostate-specific antigen level >20 ng/mL). Patients were treated with 45 Gy in 25 fractions to the pelvic lymph nodes using a conventional four-field technique. A concomitant intensity-modulated radiotherapy boost of 22.5 Gy in 25 fractions was delivered to the prostate. Thus, the prostate received 67.5 Gy in 25 fractions within 5 weeks. Next, the patients underwent 3 years of adjuvant androgen ablative therapy. Acute toxicities were assessed using the Common Terminology Criteria for Adverse Events, version 3.0, weekly during treatment and at 3 months after RT. Results: The median patient age was 71 years. The median pretreatment prostate-specific antigen level and Gleason score was 18.7 ng/L and 8, respectively. Grade 1-2 genitourinary and gastrointestinal toxicities were common during RT but most had settled at 3 months after treatment. Only 5 patients had acute Grade 3 genitourinary toxicity, in the form of urinary incontinence (n = 1), urinary frequency/urgency (n = 3), and urinary retention (n = 1). None of the patients developed Grade 3 or greater gastrointestinal or Grade 4 or greater genitourinary toxicity. Conclusion: The results of the present study have indicated that hypofractionated accelerated RT with a concomitant intensity-modulated RT boost and pelvic nodal irradiation is feasible with acceptable acute toxicity

  6. Can field-in-field technique replace wedge filter in radiotherapy treatment planning: a comparative analysis in various treatment sites

    International Nuclear Information System (INIS)

    Prabhakar, R.; Julka, P.K.; Rath, G.K.

    2008-01-01

    The aim of the study was to show whether field-in-field (FIF) technique can be used to replace wedge filter in radiation treatment planning. The study was performed in cases where wedges are commonly used in radiotherapy treatment planning. Thirty patients with different malignancies who received radiotherapy were studied. This includes patients with malignancies of brain, head and neck, breast, upper and lower abdomen. All the patients underwent computed tomography scanning and the datasets were transferred to the treatment planning system. Initially, wedge based planning was performed to achieve the best possible dose distribution inside the target volume with multileaf collimators (Plan1). Wedges were removed from a copy of the same plan and FIF plan was generated (Plan2). The two plans were then evaluated and compared for mean dose, maximum dose, median dose, doses to 2% (D 2 ) and 98% (D 9 8) of the target volume, volume receiving greater than 107% of the prescribed dose (V>107%), volume receiving less than 95% of the prescribed dose (V 2 , V>107% and CI for more of the sites with statistically significant reduction in monitor units. FIF results in better dose distribution in terms of homogeneity in most of the sites. It is feasible to replace wedge filter with FIF in radiotherapy treatment planning.

  7. Postoperative radiotherapy in stage III non-small cell lung cancer: Is a reassessment necessary in modern times?

    OpenAIRE

    Billiet, Charlotte

    2017-01-01

    Background: The role of postoperative radiation therapy (PORT) in patients with completely resected non-small cell lung cancer (NSCLC) with pathologically involved mediastinal lymph nodes (N2) remains unclear. Despite a reduction of local recurrence (LR), its effect on overall survival (OS) remains unproven. Therefore we conducted a review of the current literature. Methods: To investigate the benefit and safety of modern PORT, we identified published phase III trials for PORT. We inves...

  8. Comparison between intensity modulated radiotherapy (IMRT) and 3D tangential beams technique used in patients with early-stage breast cancer who received breast-conserving therapy

    International Nuclear Information System (INIS)

    Sas-Korczynska, B.; Kokoszka, A.; Korzeniowski, S.; Sladowska, A.; Rozwadowska-Bogusz, B.; Lesiak, J.; Dyczek, S.

    2010-01-01

    Background: The most often found complications in patients with breast cancer who received radiotherapy are cardiac and pulmonary function disorders and development of second malignancies. Aim: To compare the intensity modulated radiotherapy with the 3D tangential beams technique in respect of dose distribution in target volume and critical organs they generate in patients with early-stage breast cancer who received breast-conserving therapy. Materials and methods: A dosimetric analysis was performed to assess the three radiotherapy techniques used in each of 10 consecutive patients with early-stage breast cancer treated with breast-conserving therapy. Radiotherapy was planned with the use of all the three techniques: 3D tangential beams with electron boost, IMRT with electron boost, and intensity modulated radiotherapy with simultaneous integrated boost. Results: The use of the IMRT techniques enables more homogenous dose distribution in target volume. The range of mean and median dose to the heart and lung was lower with the IMRT techniques in comparison to the 3D tangential beams technique. The range of mean dose to the heart amounted to 0.3 - 3.5 Gy for the IMRT techniques and 0.4 - 4.3 for the tangential beams technique. The median dose to the lung on the irradiated side amounted to 4.9 - 5 Gy for the IMRT techniques and 5.6 Gy for the 3D tangential beams technique. Conclusion: The application of the IMRT techniques in radiotherapy patients with early-stage breast cancer allows to obtain more homogenous dose distribution in target volume, while permitting to reduce the dose to critical organs. (authors)

  9. PREFACE: IX International Conference on Modern Techniques of Plasma Diagnostics and their Application

    Science.gov (United States)

    Savjolov, A. S.; Dodulad, E. I.

    2016-01-01

    The IX Conference on ''Modern Techniques of Plasma Diagnosis and their Application'' was held on 5 - 7 November, 2014 at National Research Nuclear University MEPhI (NRNU MEPhI). The goal of the conference was an exchange of information on both high-temperature and low-temperature plasma diagnostics as well as deliberation and analysis of various diagnostic techniques and their applicability in science, industry, ecology, medicine and other fields. The Conference also provided young scientists from scientific centres and universities engaged in plasma diagnostics with an opportunity to attend the lectures given by the leading specialists in this field as well as present their own results and findings. The first workshop titled ''Modern problems of plasma diagnostics and their application for control of chemicals and the environment'' took place at Moscow Engineering and Physics Institute (MEPhI) in June 1998 with the support of the Section on Diagnostics of the Council of Russian Academic of Science on Plasma Physics and since then these forums have been held at MEPhI every two years. In 2008 the workshop was assigned a conference status. More than 150 specialists on plasma diagnostics and students took part in the last conference. They represented leading Russian scientific centres (such as Troitsk Institute of Innovative and Thermonuclear Research, National Research Centre ''Kurchatov Institute'', Russian Federal Nuclear Centre - All-Russian Scientific Research Institute of Experimental Physics and others) and universities from Belarus, Ukraine, Germany, USA, Belgium and Sweden. About 30 reports were made by young researchers, students and post-graduate students. All presentations during the conference were broadcasted online over the internet with viewers in Moscow, Prague, St. Petersburgh and other cities. The Conference was held within the framework of the Centre of Plasma, Laser Research and Technology supported by MEPhI Academic Excellence Project (Russian

  10. PREFACE: 21th International Conference for Students and Young Scientists: Modern Technique and Technologies (MTT'2015)

    Science.gov (United States)

    2015-10-01

    Involving young researchers in the scientific process, and allowing them to gain scientific experience, are important issues for scientific development. The International Conference for Students and Young Scientists ''Modern Technique and Technologies'' is one of a number of scientific events, held at National Research Tomsk Polytechnic University aimed at training and forming the scientific elite. During previous years the conference established itself as a serious scientific event at an international level, attracting members which annually number about 400 students and young scientists from Russia and near and far abroad. An important indicator of this scientific event is the large number of scientific areas covered, such as power engineering, heat power engineering, electronic devices for monitoring and diagnostics, instrumentation, materials and technologies of new generations, methods of research and diagnostics of materials, automatic control and system engineering, physical methods science and engineering, design and artistic aspects of engineering, social and humanitarian aspects of engineering. The main issues, which are discussed at the conference by young researchers, are connected with analysis of contemporary problems, application of new techniques and technologies, and consideration of their relationship. Over the years, the conference committee has gained a lot of experience in organizing scientific meetings. There are all the necessary conditions: the staff of organizers includes employees of Tomsk Polytechnic University; the auditoriums are equipped with modern demonstration and office equipment; leading scientists are TPU professors; the status of the Tomsk Polytechnic University as a leading research university in Russia also plays an important role. All this allows collaboration between leading scientists from all around the world, who are annually invited to give lectures at the conference. The editorial board expresses gratitude to the

  11. Modern trends in the conservative management of lower jaw radio-necrosis following radiotherapy for tongue cancer

    International Nuclear Information System (INIS)

    Dapkova, L.

    1997-01-01

    This is a report on radio-necrosis of the lower jaw developing after radiation treatment for tongue cancer. Brief literature data concerning lower jaw osteoradionecrosis are presented, including incidence rate, dependence on the type of irradiation and doses applied and overall therapeutic approach to the lesion. An original scheme for complex conservative management, consistent with the specific pathogenetic patterns of post-irradiation necrosis, promoting active osteogenesis is proposed. It includes: antibiotics (4 quinolines, metronidazole, lincomycin, cephalosporin, nystatin), local antiseptic drugs (gargle with camomile, sol. tripaflavini 2 per cent, borax-glycerin, sterile 10 per cent solution of sodium chloride and the like), Miacalcic (calcitonin), vitamin D2, calcium-phospho C, parenteral nutrition, vitamins, retabolil, analgesics (general and local). The scheme, used in three patients with lower jaw radio-necrosis developing after radiotherapy for lingual cancer, yields very good results - pain relief, disappearance of trismus, with nutrition and sleep returning to normal. After demarcation of the necrotic tissue, sequestrectomy is done with ensuing complete epithelization. Lower jaw integrity is preserved without any functional and cosmetic defects. The duration of treatment is 8, 4 and 2 months, respectively (author)

  12. Development of physical and numerical techniques of Alanine/EPR dosimetry in radiotherapy

    International Nuclear Information System (INIS)

    Castro, F.; Ponte, F.; Pereira, L.

    2006-01-01

    In this work, a set of 50 alanine dosimeters has been used in a radiotherapy context, simulating a two-dimensional treatment in a non-overlapping dosimeter configuration. The dose is reconstructed from physical and numerical simulation of the electron paramagnetic resonance signal, calculating the spin density. Thus, it can be used to better adjust the error in the calibration curve to give a final accuracy of <0.03 Gy. A complete set of experimental test parameters have been used with a standard dosimeter in order to obtain the best analysis configuration. These results indicate that for a conventional treatment of some hundreds of mGy, this method can be useful with a correct signal validation. A numerical test and fitting software has been developed. The general use of alanine/electron paramagnetic resonance dosimetry in radiotherapy context is discussed. (authors)

  13. [A brief history of resuscitation - the influence of previous experience on modern techniques and methods].

    Science.gov (United States)

    Kucmin, Tomasz; Płowaś-Goral, Małgorzata; Nogalski, Adam

    2015-02-01

    Cardiopulmonary resuscitation (CPR) is relatively novel branch of medical science, however first descriptions of mouth-to-mouth ventilation are to be found in the Bible and literature is full of descriptions of different resuscitation methods - from flagellation and ventilation with bellows through hanging the victims upside down and compressing the chest in order to stimulate ventilation to rectal fumigation with tobacco smoke. The modern history of CPR starts with Kouwenhoven et al. who in 1960 published a paper regarding heart massage through chest compressions. Shortly after that in 1961Peter Safar presented a paradigm promoting opening the airway, performing rescue breaths and chest compressions. First CPR guidelines were published in 1966. Since that time guidelines were modified and improved numerously by two leading world expert organizations ERC (European Resuscitation Council) and AHA (American Heart Association) and published in a new version every 5 years. Currently 2010 guidelines should be obliged. In this paper authors made an attempt to present history of development of resuscitation techniques and methods and assess the influence of previous lifesaving methods on nowadays technologies, equipment and guidelines which allow to help those women and men whose life is in danger due to sudden cardiac arrest. © 2015 MEDPRESS.

  14. Comparative study of modern extraction techniques for the determination of environmental samples (M14)

    International Nuclear Information System (INIS)

    Gfrerer, M.; Lankmayr, E.

    2002-01-01

    Full text: The aim of any extraction method in analytical chemistry is, to effectively separate the analytes from the matrix. The whole step should be fast and quantitative with minimal solvent and time required. The classical Soxhlet extraction usually requires large volumes (up to 200 ml) of solvent to be refluxed through the solid samples for several hours. Therefore, in the last decades, alternatives for this extraction method have been presented and investigated such as ultrasonic extraction (UE), supercritical fluid extraction (SFE), accelerated solvent extraction (ASE), microwave-assisted extraction (MAE) and fluidized-bed extraction (FBE). The actual choice for analytical application is frequently the initial capital cost, operating costs, simplicity of operation, amount of organic solvent required and sample throughput. Since sample preparation is a critical step in the analytical cycle, special care has to be taken for an accurate choice and optimization of extraction techniques and clean-up procedures. Therefore, MAE and FBE were investigated for their influential extraction parameters and these parameters were optimized for the extraction of organochlorine biocides, polychlorinated biphenyls and polycyclic aromatic hydrocarbons from environmental matrices like soil, sediment and sewage sludge. The extraction yields were compared with those obtained by Soxhlet extraction performed following DIN-methods. Finally, the optimized modern methods were validated by systematic experiments with certified reference materials. Refs. 3 (author)

  15. Measurement and modeling of out-of-field doses from various advanced post-mastectomy radiotherapy techniques

    Science.gov (United States)

    Yoon, Jihyung; Heins, David; Zhao, Xiaodong; Sanders, Mary; Zhang, Rui

    2017-12-01

    More and more advanced radiotherapy techniques have been adopted for post-mastectomy radiotherapies (PMRT). Patient dose reconstruction is challenging for these advanced techniques because they increase the low out-of-field dose area while the accuracy of out-of-field dose calculations by current commercial treatment planning systems (TPSs) is poor. We aim to measure and model the out-of-field radiation doses from various advanced PMRT techniques. PMRT treatment plans for an anthropomorphic phantom were generated, including volumetric modulated arc therapy with standard and flattening-filter-free photon beams, mixed beam therapy, 4-field intensity modulated radiation therapy (IMRT), and tomotherapy. We measured doses in the phantom where the TPS calculated doses were lower than 5% of the prescription dose using thermoluminescent dosimeters (TLD). The TLD measurements were corrected by two additional energy correction factors, namely out-of-beam out-of-field (OBOF) correction factor K OBOF and in-beam out-of-field (IBOF) correction factor K IBOF, which were determined by separate measurements using an ion chamber and TLD. A simple analytical model was developed to predict out-of-field dose as a function of distance from the field edge for each PMRT technique. The root mean square discrepancies between measured and calculated out-of-field doses were within 0.66 cGy Gy-1 for all techniques. The IBOF doses were highly scattered and should be evaluated case by case. One can easily combine the measured out-of-field dose here with the in-field dose calculated by the local TPS to reconstruct organ doses for a specific PMRT patient if the same treatment apparatus and technique were used.

  16. Radiotherapy of prostate cancer

    International Nuclear Information System (INIS)

    Krause, S.; Herfarth, K.

    2011-01-01

    With the development of modern radiation techniques, such as intensity-modulated radiotherapy (IMRT), a dose escalation in the definitive radiotherapy of prostate cancer and a consecutive improvement in biochemical recurrence-free survival (BFS) could be achieved. Among others, investigators at the Memorial Sloan-Kettering Cancer Center (MSKCC) saw 5-year BFS rates of up to 98%. A further gain in effectiveness and safety is expected of hypofractionation schedules, as suggested by data published by Kupelian et al., who saw a low 5-year rate of grade ≥2 rectal side-effects of 4.5%. However, randomized studies are just beginning to mature. Patients with intermediate or high-risk tumors should receive neoadjuvant (NHT) and adjuvant (AHT) androgen deprivation. Bolla et al. could show an increase in 5-year overall survival from 62-78%. The inclusion of the whole pelvis in the treatment field (WPRT) is still controversial. The RTOG 94-13 study showed a significant advantage in disease-free survival after 60 months but long-term data did not yield significant differences between WPRT and irradiation of the prostate alone. The German Society of Urology strongly recommends adjuvant radiotherapy of the prostate bed for pT3 N0 tumors with positive margins. In a pT3 N0 R0 or pT2 N0 R+ situation, adjuvant radiotherapy should at least be considered. So far, no randomized data on NHT and AHT have been published, so androgen deprivation remains an individual decision in the postoperative setting. In a retrospective analysis Spiotto et al. reported a positive effect for adjuvant WPRT and biochemical control. This article summarizes the essential publications on definitive and adjuvant radiotherapy and discusses the additional use of androgen deprivation and WPRT. (orig.) [de

  17. Intensity modulation in breast radiotherapy: Development of an innovative field-in-field technique at Institut Gustave-Roussy

    International Nuclear Information System (INIS)

    Heymann, S.; Bourhis, J.; Bourgier, C.; Verstraet, R.; Pichenot, C.; Vergne, E.; Lefkopoulos, D.; Husson, F.; Kafrouni, H.; Mahe, J.; Kandalaft, B.; Marsiglia, H.

    2011-01-01

    Purpose. - To assess the potential dosimetric gain of pre-segmentation modulated radiotherapy (OAPS, DosiSoft TM ) of breast, compared to routine 3D conformal radiotherapy. Patients and methods. - Twenty patients treated with conservative surgery for breast cancer (9 right and 11 left sided) with various breast volume (median 537 cm 3 ; range [100-1049 cm 3 ]) have been selected. For each patient, we have delineated a breast volume and a compensation volume (target volumes), as well as organs at risk (lungs and heart). Two treatment plans have been generated: one using the routine 3D conformal technique and the other with the pre-segmentation algorithm of DosiSoft TM (OAPS). The dose distribution were analyzed using the conformity index for target volumes, mean dose and V 30 Gy for the heart, and mean dose, V 20 Gy and V 30 Gy for lungs. Results. - Over the 20 patients, the conformity index increased from 0.897 with routine technique to 0.978 with OAPS (P TM ) is an original method of segmentation of breast. It is automatic, fast and easy, and is able to increase the conformity index, while sparing organ at risk. (authors)

  18. Conventional (2D) Versus Conformal (3D) Techniques in Radiotherapy for Malignant Pediatric Tumors: Dosimetric Perspectives

    International Nuclear Information System (INIS)

    Ahmad, N.; Attia, G.; Radwan, A.; El-Badawy, S.; El-Ghoneimy, E.

    2009-01-01

    Objectives: In pediatric radiotherapy, the enhanced radiosensitivity of the developing tissues combined with the high overall survival, raise the possibility of late complications. The present study aims at comparing two dimensional (2D) and three dimensional (3D) planning regarding dose homogeneity within target volume and dose to organs at risk (OARs) to demonstrate the efficacy of 3D in decreasing dose to normal tissue. Material and Methods: Thirty pediatric patients (18 years or less) with different pediatric tumors were planned using 2D and 3D plans. All were CT scanned after proper positioning and immobilization. Structures were contoured; including the planning target volume (PTV) and organs at risk (OARs). Conformal beams were designed and dose distribution analysis was edited to provide the best dose coverage to the PTV while sparing OARs using dose volume histograms (DVHs) of outlined structures. For the same PTVs conventional plans were created using the conventional simulator data (2-4 coplanar fields). Conventional and 3D plans coverage and distribution were compared using the term of V95% (volume of PTV receiving 95% of the prescribed dose), V107% (volume of PTV receiving 107% of the prescribed dose), and conformity index (CI) (volume receiving 90% of the prescribed dose/PTV). Doses received by OARs were compared in terms of mean dose. In children treated for brain lesions, OAR volume received 90% of the dose (V 90%) and OAR score were calculated. Results: The PTV coverage showed no statistical difference between 2D and 3D radiotherapy in terms of V95% or V107%. However, there was more conformity in 3D planning with CI 1.43 rather than conventional planning with CI 1.86 (p-value <0.001). Regarding OARs, 3D planning shows large gain in healthy tissue sparing. There was no statistical difference in mean dose received by each OAR. However, for brain cases, brain stem mean dose and brain V 90% showed better sparing in 3D planning (brain stem mean dose was

  19. Conformation radiotherapy and conformal radiotherapy

    International Nuclear Information System (INIS)

    Morita, Kozo

    1999-01-01

    In order to coincide the high dose region to the target volume, the 'Conformation Radiotherapy Technique' using the multileaf collimator and the device for 'hollow-out technique' was developed by Prof. S. Takahashi in 1960. This technique can be classified a type of 2D-dynamic conformal RT techniques. By the clinical application of this technique, the late complications of the lens, the intestine and the urinary bladder after radiotherapy for the maxillary cancer and the cervical cancer decreased. Since 1980's the exact position and shape of the tumor and the surrounding normal tissues can be easily obtained by the tremendous development of the CT/MRI imaging technique. As a result, various kinds of new conformal techniques such as the 3D-CRT, the dose intensity modulation, the tomotherapy have been developed since the beginning of 1990'. Several 'dose escalation study with 2D-/3D conformal RT' is now under way to improve the treatment results. (author)

  20. CyberKnife robotic stereotactic radiotherapy: technical aspects and medical indications; Radiotherapie stereotaxique robotisee par CyberKnife: aspects techniques et indications

    Energy Technology Data Exchange (ETDEWEB)

    Bondiau, P.Y.; Benezery, K.; Gerard, J.P.; Herault, J.; Marcie, S.; Angellier, G. [Centre Antoine-Lacassagne, Dept. de Radiotherapie, 06 - Nice (France); Beckendorf, V.; Peiffert, D.; Noel, A. [Centre Alexis-Vautrin, Dept. de Radiotherapie et Curietherapie, 54 - Vandoeuvre-les-Nancy (France); Mirabel, X.; Marchesi, V.; Lacornerie, T.; Dubus, F.; Sarrazin, T.; Lartigau, E. [Centre Oscar-Lambret, Dept. de Radiotherapie, 59 - Lille (France)

    2007-11-15

    In 2006, 3 sites have been selected by the Institut national of cancer (Lille, Nancy et Nice) to evaluate a radiotherapy robot, the CyberKnife this machine, able to track mobile tumours in real time, gives new possibilities in the field of extra cranial stereotactic radiotherapy. Functionalities and medico economical issues of the machine will be evaluated during 2 years on the 3 sites. (authors)

  1. External beam radiotherapy for head and neck carcinomas with preservation of parotid function: indications, techniques and long term results

    International Nuclear Information System (INIS)

    Ding-Jen, Lee; Fairbanks, Robert; Lee, Frank C.

    1995-01-01

    Purpose/Objective: To reduce the incidence of radiotherapy induced xerostomia, we developed techniques of external beam irradiation with preservation of parotid function for patients with early to intermediate stage carcinomas of the head and neck. This analysis reports the efficacy of our methods. Materials and Methods: From 1985 to 1993, 42 patients with early to intermediate stage (T 1-3 N 0-2 M 0 ) head and neck carcinomas received a course of external beam radiotherapy. There were 13 patients with carcinoma of the oropharynx, 26 with carcinomas of the oral cavity and 3 with carcinomas of the hypopharynx (lateral wall). 7 patients received a course of definitive radiotherapy (66 to 72 Gy), while 35 patients received a course of postoperative radiotherapy (60-66 Gy). The fraction size was 2 Gy per day. In terms of treatment planning, the primary site (plus a margin) and the ipsilateral neck were covered by the irradiation volume. The ipsilateral parotid gland was within the treatment volume while the contralateral parotid gland was not. The most frequently used field arrangement was a paired wedge fields with an AP (medially just across the mid-line) and an ipsilateral posterior oblique field (usually 30 deg. off vertical axis with a spinal cord block). Multiple level of contours were taken and transmission blocks were used to improve dose homogeneity. In all patients, the ipsilateral parotid gland (and the neck) was irradiated while the contralateral parotid gland (and the neck) was not. Results: With a median follow up of 4 years (ranged from 1.5 to 9 years), only one patient developed symptomatic xerostomia. None had radiation induced dental caries. No patient developed recurrent disease in the contralateral neck. The local control rate was (38(42)) (90%) in the primary site and(41(42)) (98%) in the ipsilateral neck. Conclusion: With appropriate treatment planning, external beam irradiation with parotid function preservation can be achieved. Our results

  2. Oral Health and Experiences of Oral Care in Radiotherapy Patients ...

    African Journals Online (AJOL)

    Background: In spite of careful planning and modern techniques, radiotherapy inevitably involves side-effects due to exposure of surrounding normal tissues. Patients treated for head and neck cancer who experience oral symptoms do not always consider these symptoms to be related to their disease or its treatment.

  3. Radiotherapy; Strahlentherapie

    Energy Technology Data Exchange (ETDEWEB)

    Wannenmacher, M. [Heidelberg Univ., Mannheim (Germany). Abt. fuer Klinische Radiologie; Debus, J. [Univ. Heidelberg (Germany). Abt. Radioonkologie und Strahlentherapie; Wenz, F. (eds.) [Universitaetsklinikum Mannheim (Germany). Klinik fuer Strahlentherapie und Radioonkologie

    2006-07-01

    The book is focussed on the actual knowledge on the clinical radiotherapy and radio-oncology. Besides fundamental and general contributions specific organ systems are treated in detail. The book contains the following contributions: Basic principles, radiobiological fundamentals, physical background, radiation pathology, basics and technique of brachytherapy, methodology and technique of the stereotactic radiosurgery, whole-body irradiation, operative radiotherapy, hadron therapy, hpyerthermia, combined radio-chemo-therapy, biometric clinical studies, intensity modulated radiotherapy, side effects, oncological diagnostics; central nervous system and sense organs, head-neck carcinomas, breast cancer, thorax organs, esophagus carcinoma, stomach carcinoma, pancreas carcinoma, heptabiliary cancer and liver metastases, rectal carcinomas, kidney and urinary tract, prostate carcinoma, testicular carcinoma, female pelvis, lymphatic system carcinomas, soft tissue carcinoma, skin cancer, bone metastases, pediatric tumors, nonmalignant diseases, emergency in radio-oncology, supporting therapy, palliative therapy.

  4. A comparison of conformal and intensity-modulated techniques for oesophageal radiotherapy

    International Nuclear Information System (INIS)

    Nutting, Christopher M.; Bedford, James L.; Cosgrove, Vivian P.; Tait, Diana M.; Dearnaley, David P.; Webb, Steve

    2001-01-01

    Background and purpose: To investigate the potential of intensity-modulated radiotherapy (IMRT) to reduce lung irradiation in the treatment of oesophageal carcinoma with radical radiotherapy. Materials and methods: A treatment planning study was performed to compare two-phase conformal radiotherapy (CFRT) with IMRT in five patients. The CFRT plans consisted of anterior, posterior and bilateral posterior oblique fields, while the IMRT plans consisted of either nine equispaced fields (9F), or four fields (4F) with orientations equal to the CFRT plans. IMRT plans with seven, five or three equispaced fields were also investigated in one patient. Treatment plans were compared using dose-volume histograms and normal tissue complication probabilities. Results: The 9F IMRT plan was unable to improve on the homogeneity of dose to the planning target volume (PTV), compared with the CFRT plan (dose range, 16.9±4.5 (1 SD) vs. 12.4±3.9%; P=0.06). Similarly, the 9F IMRT plan was unable to reduce the mean lung dose (11.7±3.2 vs. 11.0±2.9 Gy; P=0.2). Similar results were obtained for seven, five and three equispaced fields in the single patient studied. The 4F IMRT plan provided comparable PTV dose homogeneity with the CFRT plan (11.8±3.3 vs. 12.4±3.9%; P=0.6), with reduced mean lung dose (9.5±2.3 vs 11.0±2.9 Gy; P=0.001). Conclusions: IMRT using nine equispaced fields provided no improvement over CFRT. This was because the larger number of fields in the IMRT plan distributed a low dose over the entire lung. In contrast, IMRT using four fields equal to the CFRT fields offered an improvement in lung sparing. Thus, IMRT with a few carefully chosen field directions may lead to a modest reduction in pneumonitis, or allow tumour dose escalation within the currently accepted lung toxicity

  5. Applying modern psychometric techniques to melodic discrimination testing: Item response theory, computerised adaptive testing, and automatic item generation.

    Science.gov (United States)

    Harrison, Peter M C; Collins, Tom; Müllensiefen, Daniel

    2017-06-15

    Modern psychometric theory provides many useful tools for ability testing, such as item response theory, computerised adaptive testing, and automatic item generation. However, these techniques have yet to be integrated into mainstream psychological practice. This is unfortunate, because modern psychometric techniques can bring many benefits, including sophisticated reliability measures, improved construct validity, avoidance of exposure effects, and improved efficiency. In the present research we therefore use these techniques to develop a new test of a well-studied psychological capacity: melodic discrimination, the ability to detect differences between melodies. We calibrate and validate this test in a series of studies. Studies 1 and 2 respectively calibrate and validate an initial test version, while Studies 3 and 4 calibrate and validate an updated test version incorporating additional easy items. The results support the new test's viability, with evidence for strong reliability and construct validity. We discuss how these modern psychometric techniques may also be profitably applied to other areas of music psychology and psychological science in general.

  6. Head and neck cancers: clinical benefits of three-dimensional conformal radiotherapy and of intensity-modulated radiotherapy

    International Nuclear Information System (INIS)

    Giraud, P.; Jaulerry, C.; Brunin, F.; Zefkili, S.; Helfre, S.; Chauvet, I.; Rosenwald, J.C.; Cosset, J.M.

    2002-01-01

    The conformal radiotherapy approach, three-dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT), is based on modern imaging modalities, efficient 3-D treatment planning systems, sophisticated immobilization systems and rigorous quality assurance and treatment verification. The central objective of conformal radiotherapy is to ensure a high dose distribution tailored to the limits of the target volume while reducing exposure of normal tissues. These techniques would then allow further tumor dose escalation. Head-and-neck tumors are some of the most attractive localizations to test conformal radiotherapy. They combine ballistic difficulties due to particularly complex shapes (nasopharynx, ethmoid) and problems due to the number and low tolerance of neighbouring organs like parotids, eyes, brainstem and spinal cord. The therapeutic irradiation of head-and-neck tumors thus remains a challenge for the radiation oncologist. Conformal radiotherapy does have a significant potential for improving local control and reducing toxicity when compared to standard radiotherapy. However, in the absence of prospective randomized trials, it is somewhat difficult at present to evaluate the real benefits drawn from 3DCRT and IMRT. The published clinical reports on the use of conformal radiotherapy are essentially dealing with dosimetric comparisons on relatively small numbers of patients. Recently, a few publications have emphasized the clinical experience several precursor teams with a suitable follow-up. This paper describes the current state-of-the-art of 3DCRT and IMRT in order to evaluate the impact of these techniques on head-and-neck cancers irradiation. (authors)

  7. A review of post-modern management techniques as currently applied to Turkish forestry.

    Science.gov (United States)

    Dölarslan, Emre Sahin

    2009-01-01

    This paper reviews the effects of six post-modern management concepts as applied to Turkish forestry. Up to now, Turkish forestry has been constrained, both in terms of its operations and internal organization, by a highly bureaucratic system. The application of new thinking in forestry management, however, has recently resulted in new organizational and production concepts that promise to address problems specific to this Turkish industry and bring about positive changes. This paper will elucidate these specific issues and demonstrate how post-modern management thinking is influencing the administration and operational capacity of Turkish forestry within its current structure.

  8. Design and implementation of a rotational radiotherapy technique for breast cancer treatment and their comparison with 3-D-Crt irradiation technique

    International Nuclear Information System (INIS)

    Gutierrez M, J. G.; Lopez V, A.; Rivera M, T.; Velazquez T, J. J.; Adame G, C. S.; Rubio N, O.; Chagoya G, A.; Hernandez G, J. C.

    2015-10-01

    Breast cancer is one of oncological diseases worldwide, as well in Mexico, which causes even more deaths than cervical cancer; this condition is the second death cause in women aged 30-54 years and threatens all socio-economic groups. The treatment is highly dependent on the stage which is detected and based on protocols that include a combination of surgery, chemotherapy and radiotherapy. This paper studies the main irradiation technique for patients with mastectomy, breast full cycle (irradiation of the chest well and supraclavicular nodes) in their mode Three Dimensional - Conformal Radiation Therapy (3-D-Crt), and compared with the Volumetric Modulated Arc Therapy (VMAT) technique proposed in this paper. In both techniques the prescription was 50 Gy divided into 25 fractions. The techniques were applied in three female patients (being an initial study) with disease of the left side, the target volume and organs at risk were delineated by the medical treating radiation oncologist, the planning system used was Eclipse version 10; for quantitative comparison of both plans indexes of homogeneity were used, con formality, the target volume coverage and normal tissue, sub factors and overdosing, the conformation number and coverage quality. They were evaluated and compared the media, maximum and minimum dose of the organs at risk, based on the fact that the coverage of the target volume, dose gradient and dose at risk organs are acceptable (prescription dose greater that 90% coverage, gradient less that 20% and organs at risk in accordance with the Quantec limitations for both versions). (Author)

  9. Modern Methodology and Techniques Aimed at Developing the Environmentally Responsible Personality

    Science.gov (United States)

    Ponomarenko, Yelena V.; Zholdasbekova, Bibisara A.; Balabekov, Aidarhan T.; Kenzhebekova, Rabiga I.; Yessaliyev, Aidarbek A.; Larchenkova, Liudmila A.

    2016-01-01

    The article discusses the positive impact of an environmentally responsible individual as the social unit able to live in harmony with the natural world, himself/herself and other people. The purpose of the article is to provide theoretical substantiation of modern teaching methods. The authors considered the experience of philosophy, psychology,…

  10. Segmental and dynamic intensity-modulated radiotherapy delivery techniques for micro-multileaf collimator

    International Nuclear Information System (INIS)

    Agazaryan, Nzhde; Solberg, Timothy D.

    2003-01-01

    A leaf sequencing algorithm has been implemented to deliver segmental and dynamic multileaf collimated intensity-modulated radiotherapy (SMLC-IMRT and DMLC-IMRT, respectively) using a linear accelerator equipped with a micro-multileaf collimator (mMLC). The implementation extends a previously published algorithm for the SMLC-IMRT to include the dynamic MLC-IMRT method and several dosimetric considerations. The algorithm has been extended to account for the transmitted radiation and minimize the leakage between opposing and neighboring leaves. The underdosage problem associated with the tongue-and-groove design of the MLC is significantly reduced by synchronizing the MLC leaf movements. The workings of the leaf sequencing parameters have been investigated and the results of the planar dosimetric investigations show that the sequencing parameters affect the measured dose distributions as intended. Investigations of clinical cases suggest that SMLC and DMLC delivery methods produce comparable results with leaf sequences obtained by root-mean-square (RMS) errors specification of 1.5% and lower, approximately corresponding to 20 or more segments. For SMLC-IMRT, there is little to be gained by using an RMS error specification smaller than 2%, approximately corresponding to 15 segments; however, more segments directly translate to longer treatment time and more strain on the MLC. The implemented leaf synchronization method does not increase the required monitor units while it reduces the measured TG underdoses from a maximum of 12% to a maximum of 3% observed with single field measurements of representative clinical cases studied

  11. Radiobiological analysis of the field in field technique in breast cancer radiotherapy treatments

    Energy Technology Data Exchange (ETDEWEB)

    Medel B, E.; Vasquez R, M. A. [IMSS, Centro Medico Nacional Manuel Avila Camacho, Calle 2 Nte. 2004, Barrio de San Francisco, 72090 Puebla, Pue. (Mexico); Tejeda M, G., E-mail: marcosalivasquez@gmail.com [Benemerita Universidad Autonoma de Puebla, Facultad de Ciencias Fisico Matematicas, Av. San Claudio y 18 Sur, Ciudad Universitaria, 72570 Puebla, Pue. (Mexico)

    2015-10-15

    Full text: In vivo dosimetry was performed in 6 unilateral breast cancer patients treated with external beam radiation therapy in order to evaluate the dose calculated by the radiotherapy treatment planning system (Xi O, ELEKTA). Results show a maximum difference of 0.473 Gy between the dose calculated by the treatment planning system and the dose measured in vivo using solid state detectors. Based on the DVHs statistics, tumor control probability (Tcp) was obtained using the Target-Poisson model, with the following Tcp parameters: α=0.288/Gy, α{sub s}pread= 0.13 and α/β=4.9 Gy. Tcp average obtained for the Clinical Tumor Volume (Ctv) is 35.1% and for Supra Clavicle Volume (Scv) is 35.345%. Finally using Lyman model Normal Tissue Complication Probability (Ntcp) was obtained for the following endpoints: contralateral breast fibrosis, lung radiation pneumonitis and heart pericarditis. Nonetheless the Ntcp values are not high; the improvement of the Tcp based on this plan makes Ntcp for lung radiation pneumonitis reach the 100% of probability in some cases. (Author)

  12. A technique for generating phase-space-based Monte Carlo beamlets in radiotherapy applications

    International Nuclear Information System (INIS)

    Bush, K; Popescu, I A; Zavgorodni, S

    2008-01-01

    As radiotherapy treatment planning moves toward Monte Carlo (MC) based dose calculation methods, the MC beamlet is becoming an increasingly common optimization entity. At present, methods used to produce MC beamlets have utilized a particle source model (PSM) approach. In this work we outline the implementation of a phase-space-based approach to MC beamlet generation that is expected to provide greater accuracy in beamlet dose distributions. In this approach a standard BEAMnrc phase space is sorted and divided into beamlets with particles labeled using the inheritable particle history variable. This is achieved with the use of an efficient sorting algorithm, capable of sorting a phase space of any size into the required number of beamlets in only two passes. Sorting a phase space of five million particles can be achieved in less than 8 s on a single-core 2.2 GHz CPU. The beamlets can then be transported separately into a patient CT dataset, producing separate dose distributions (doselets). Methods for doselet normalization and conversion of dose to absolute units of Gy for use in intensity modulated radiation therapy (IMRT) plan optimization are also described. (note)

  13. Treatment planning evaluation of non-coplanar techniques for conformal radiotherapy of the prostate

    International Nuclear Information System (INIS)

    Bedford, James L.; Henrys, Anthony J.; Dearnaley, David P.; Khoo, Vincent S.

    2005-01-01

    Background and purpose: To evaluate the benefit of using non-coplanar treatment plans for irradiation of two different clinical treatment volumes: prostate only (PO) and the prostate plus seminal vesicles (PSV). Material and methods: An inverse planning algorithm was used to produce three-field, four-field, five-field and six-field non-coplanar treatment plans without intensity-modulation in ten patients. These were compared against a three-field coplanar plan. A dose of 74 Gy was prescribed to the isocentre. Plans were compared using the minimum dose to the planning target volume (PTV), maximum dose to the small bowel, and irradiated volumes of rectum, bladder and femoral head. Biological indices were also evaluated. Results: For the PO group, volume of rectum irradiated to 60 Gy (V 60 ) was 22.5±3.7% for the coplanar plan, and 21.5±5.3% for the five-field non-coplanar plan, which was the most beneficial (p=0.3). For the PSV group, the five-field non-coplanar plan was again the most beneficial. Rectal V 60 was in this case reduced from 41.5±10.4% for the coplanar plan to 35.2±9.3% for the non-coplanar plan (p=0.02). Conclusions: The use of non-coplanar beams in conformal prostate radiotherapy provides a small increase in rectal sparing, more significantly with PSV volumes than for PO volumes

  14. Socio-cultural inhibitors to use of modern contraceptive techniques in rural Uganda: a qualitative study

    Science.gov (United States)

    Kabagenyi, Allen; Reid, Alice; Ntozi, James; Atuyambe, Lynn

    2016-01-01

    Introduction Family planning is one of the cost-effective strategies in reducing maternal and child morbidity and mortality rates. Yet in Uganda, the contraceptive prevalence rate is only 30% among married women in conjunction with a persistently high fertility rate of 6.2 children per woman. These demographic indicators have contributed to a high population growth rate of over 3.2% annually. This study examines the role of socio-cultural inhibitions in the use of modern contraceptives in rural Uganda. Methods This was a qualitative study conducted in 2012 among men aged 15-64 and women aged 15-49 in the districts of Mpigi and Bugiri in rural Uganda. Eighteen selected focus group discussions (FGDs), each internally homogeneous, and eight in-depth interviews (IDIs) were conducted among men and women. Data were collected on sociocultural beliefs and practices, barriers to modern contraceptive use and perceptions of and attitudes to contraceptive use. All interviews were tape recoded, translated and transcribed verbatim. All the transcripts were coded, prearranged into categories and later analyzed using a latent content analysis approach, with support of ATLAS.ti qualitative software. Suitable quotations were used to provide in-depth explanations of the findings. Results Three themes central in hindering the uptake of modern contraceptives emerged: (i) persistence of socio-cultural beliefs and practices promoting births (such as polygamy, extending family lineage, replacement of the dead, gender-based violence, power relations and twin myths). (ii) Continued reliance on traditional family planning practices and (iii) misconceptions and fears about modern contraception. Conclusion Sociocultural expectations and values attached to marriage, women and child bearing remain an impediment to using family planning methods. The study suggests a need to eradicate the cultural beliefs and practices that hinder people from using contraceptives, as well as a need to scale

  15. Socio-cultural inhibitors to use of modern contraceptive techniques in rural Uganda: a qualitative study.

    Science.gov (United States)

    Kabagenyi, Allen; Reid, Alice; Ntozi, James; Atuyambe, Lynn

    2016-01-01

    Family planning is one of the cost-effective strategies in reducing maternal and child morbidity and mortality rates. Yet in Uganda, the contraceptive prevalence rate is only 30% among married women in conjunction with a persistently high fertility rate of 6.2 children per woman. These demographic indicators have contributed to a high population growth rate of over 3.2% annually. This study examines the role of socio-cultural inhibitions in the use of modern contraceptives in rural Uganda. This was a qualitative study conducted in 2012 among men aged 15-64 and women aged 15-49 in the districts of Mpigi and Bugiri in rural Uganda. Eighteen selected focus group discussions (FGDs), each internally homogeneous, and eight in-depth interviews (IDIs) were conducted among men and women. Data were collected on sociocultural beliefs and practices, barriers to modern contraceptive use and perceptions of and attitudes to contraceptive use. All interviews were tape recoded, translated and transcribed verbatim. All the transcripts were coded, prearranged into categories and later analyzed using a latent content analysis approach, with support of ATLAS.ti qualitative software. Suitable quotations were used to provide in-depth explanations of the findings. Three themes central in hindering the uptake of modern contraceptives emerged: (i) persistence of socio-cultural beliefs and practices promoting births (such as polygamy, extending family lineage, replacement of the dead, gender-based violence, power relations and twin myths). (ii) Continued reliance on traditional family planning practices and (iii) misconceptions and fears about modern contraception. Sociocultural expectations and values attached to marriage, women and child bearing remain an impediment to using family planning methods. The study suggests a need to eradicate the cultural beliefs and practices that hinder people from using contraceptives, as well as a need to scale-up family planning services and sensitization

  16. The perturbed angular correlation method - a modern technique in studying solids

    International Nuclear Information System (INIS)

    Unterricker, S.; Hunger, H.J.

    1979-01-01

    Starting from theoretical fundamentals the differential perturbed angular correlation method has been explained. By using the probe nucleus 111 Cd the magnetic dipole interaction in Fesub(x)Alsub(1-x) alloys and the electric quadrupole interaction in Cd have been measured. The perturbed angular correlation method is a modern nuclear measuring method and can be applied in studying ordering processes, phase transformations and radiation damages in metals, semiconductors and insulators

  17. Technique of Injection of Hyaluronic Acid as a Prostatic Spacer and Fiducials Before Hypofractionated External Beam Radiotherapy for Prostate Cancer.

    Science.gov (United States)

    Boissier, Romain; Udrescu, Corina; Rebillard, Xavier; Terrier, Jean-Etienne; Faix, Antoine; Chapet, Olivier; Azria, David; Devonec, Marian; Paparel, Philippe; Ruffion, Alain

    2017-01-01

    To describe a technique combining the implantation of fiducials and a prostatic spacer (hyaluronic acid [HA]) to decrease the rectal toxicity after an image-guided external beam radiotherapy (EBRT) with hypofractionation for prostate cancer and to assess the tolerance and the learning curve of the procedure. Thirty patients with prostate cancer at low or intermediate risk were included in a phase II trial: image-guided EBRT of 62 Gy in 20 fractions of 3.1 Gy with intensity-modulated radiotherapy. A transrectal implantation of 3 fiducials and transperineal injection of 10 cc of HA (NASHA gel spacer, Q-Med AB, Uppsala, Sweden) between the rectum and the prostate was performed by 1 operator. The thickness of HA was measured at 10 points on magnetic resonance imaging to establish a quality score of the injection (maximum score = 10) and determine the learning curve of the procedure. The quality score increased from patients 1-10, 11-20, to 21-30 with respective median scores: 7 [2-10], 5 [4-7], and 8 [3-10]. The average thicknesses of HA between the base, middle part, and apex of the prostate and the rectum were the following: 15.1 mm [6.4-29], 9.8 mm [5-21.2], and 9.9 mm [3.2-21.5]. The injection of the HA induced a median pain score of 4 [1-8] and no residual pain at mid-long term. Creating an interface between the rectum and the prostate and the implantation of fiducials were feasible under local anesthesia with a short learning curve and could become a standard procedure before a hypofractionated EBRT for prostate cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Decision to adopt medical technology: case study of breast cancer radiotherapy techniques.

    Science.gov (United States)

    Gold, Heather Taffet; Pitrelli, Kimberly; Hayes, Mary Katherine; Murphy, Madhuvanti Mahadeo

    2014-11-01

    To understand decision making concerning adoption and nonadoption of accelerated partial breast radiotherapy (RT) prior to long-term randomized trial evidence. A total of 36 radiation oncologists and surgeons were recruited through purposive and snowball sampling strategies from September 2010 through January 2013. Semistructured phone interviews were conducted and audio-recorded and lasted 20-45 minutes. Qualitative analysis was conducted using a framework approach, iteratively exploring key concepts and emerging issues raised by subjects. Interviews were transcribed and imported into Atlas.ti v6. Transcripts were independently coded by 3 researchers shortly after each interview, followed by consensus development on each coded transcript. Barriers and facilitators of adoption, practice patterns, and informational/educational sources concerning accelerated partial breast RT were all assessed to determine major themes. Nearly half of physicians were surgeons (47%), and half were radiation oncologists (53%), with 61% overall in urban settings. Twenty-nine of the 36 physicians interviewed used brachytherapy-based partial breast RT. Five major factors were involved in physicians' decisions to adopt accelerated partial breast RT: facilitators encouraging adoption (e.g., enthusiastic colleagues and patient convenience), financial and prestige incentives, pressures to adopt (e.g., potential declines in referrals), judgment concerning acceptable level of scientific evidence, and barriers (e.g., not having appropriate machinery or referral mechanism in place). If technology was adopted, clinical guideline adherence varied. Technology adoption is based on financial and social pressures, along with often-limited scientific evidence and what seems "best" for patients. For technology adoption and diffusion to be rational and evidence-based, we must encourage appropriate financial payment models to curb use outside of research studies and promote development of additional

  19. Physiological patterns during practice of the Transcendental Meditation technique compared with patterns while reading Sanskrit and a modern language.

    Science.gov (United States)

    Travis, F; Olson, T; Egenes, T; Gupta, H K

    2001-07-01

    This study tested the prediction that reading Vedic Sanskrit texts, without knowledge of their meaning, produces a distinct physiological state. We measured EEG, breath rate, heart rate, and skin conductance during: (1) 15-min Transcendental Meditation (TM) practice; (2) 15-min reading verses of the Bhagavad Gita in Sanskrit; and (3) 15-min reading the same verses translated in German, Spanish, or French. The two reading conditions were randomly counterbalanced, and subjects filled out experience forms between each block to reduce carryover effects. Skin conductance levels significantly decreased during both reading Sanskrit and TM practice, and increased slightly during reading a modern language. Alpha power and coherence were significantly higher when reading Sanskrit and during TM practice, compared to reading modern languages. Similar physiological patterns when reading Sanskrit and during practice of the TM technique suggests that the state gained during TM practice may be integrated with active mental processes by reading Sanskrit.

  20. A comparative study of standard intensity-modulated radiotherapy and RapidArc planning techniques for ipsilateral and bilateral head and neck irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Pursley, Jennifer, E-mail: jpursley@mgh.harvard.edu [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women' s Hospital, Boston, MA (United States); Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Damato, Antonio L.; Czerminska, Maria A.; Margalit, Danielle N. [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women' s Hospital, Boston, MA (United States); Sher, David J. [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women' s Hospital, Boston, MA (United States); Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX (United States); Tishler, Roy B. [Department of Radiation Oncology, Dana-Farber Cancer Institute/Brigham and Women' s Hospital, Boston, MA (United States)

    2017-04-01

    The purpose of this study was to investigate class solutions using RapidArc volumetric-modulated arc therapy (VMAT) planning for ipsilateral and bilateral head and neck (H&N) irradiation, and to compare dosimetric results with intensity-modulated radiotherapy (IMRT) plans. A total of 14 patients who received ipsilateral and 10 patients who received bilateral head and neck irradiation were retrospectively replanned with several volumetric-modulated arc therapy techniques. For ipsilateral neck irradiation, the volumetric-modulated arc therapy techniques included two 360° arcs, two 360° arcs with avoidance sectors around the contralateral parotid, two 260° or 270° arcs, and two 210° arcs. For bilateral neck irradiation, the volumetric-modulated arc therapy techniques included two 360° arcs, two 360° arcs with avoidance sectors around the shoulders, and 3 arcs. All patients had a sliding-window-delivery intensity-modulated radiotherapy plan that was used as the benchmark for dosimetric comparison. For ipsilateral neck irradiation, a volumetric-modulated arc therapy technique using two 360° arcs with avoidance sectors around the contralateral parotid was dosimetrically comparable to intensity-modulated radiotherapy, with improved conformity (conformity index = 1.22 vs 1.36, p < 0.04) and lower contralateral parotid mean dose (5.6 vs 6.8 Gy, p < 0.03). For bilateral neck irradiation, 3-arc volumetric-modulated arc therapy techniques were dosimetrically comparable to intensity-modulated radiotherapy while also avoiding irradiation through the shoulders. All volumetric-modulated arc therapy techniques required fewer monitor units than sliding-window intensity-modulated radiotherapy to deliver treatment, with an average reduction of 35% for ipsilateral plans and 67% for bilateral plans. Thus, for ipsilateral head and neck irradiation a volumetric-modulated arc therapy technique using two 360° arcs with avoidance sectors around the contralateral parotid is

  1. Lung stereotactic body radiotherapy using a coplanar versus a non-coplanar beam technique: a comparison of clinical outcomes

    Science.gov (United States)

    Stauder, Michael C.; Miller, Robert C.; Garces, Yolanda I.; Foote, Robert L.; Sarkaria, Jann N.; Bauer, Heather J.; Mayo, Charles S.; Olivier, Kenneth R.

    2013-01-01

    Objectives To determine if lung stereotactic body radiotherapy (SBRT) using a coplanar beam technique was associated with similar outcomes as lung SBRT using a non-coplanar beam technique. Methods A retrospective review was performed of patients undergoing lung SBRT between January 2008 and April 2011. SBRT was initially delivered with multiple non-coplanar, non-overlapping beams; however, starting in December 2009, SBRT was delivered predominantly with all coplanar beams in order to reduce treatment time and complexity. Results This analysis included 149 patients; the median follow-up was 21 months. SBRT was delivered for primary (n = 90) or recurrent (n = 17) non-small cell lung cancer, or lung oligometastasis (n = 42). The most common dose (Gy)/fraction (fx) regimens were 48 Gy/4 fx (39%), 54 Gy/3 fx (37%), and 50 Gy/5 fx (17%). The beam arrangement was coplanar in 61 patients (41%) and non-coplanar in 88 patients (59%). In patients treated with 54 Gy/3 fx, the mean treatment times per fraction for the coplanar and non-coplanar cohorts were 10 and 14 minutes (p < 0.0001). Kaplan-Meier 2-year estimates of overall survival (OS), progression-free survival, and local control (LC) for the coplanar and non-coplanar cohorts were 65% vs. 56% (p = 0.30), 47% vs. 39% (p = 0.71), and 92% and 92% (p = 0.94), respectively. The 1-year estimates of grade 2-5 pulmonary toxicity for the coplanar and non-coplanar cohorts were 11% and 17%, respectively (p = 0.30). On multivariate analysis, beam arrangement was not significantly associated with OS, LC or pulmonary toxicity. Conclusions Patients treated with lung SBRT using a coplanar technique had similar outcomes as those treated with a non-coplanar technique. PMID:29296365

  2. Craniospinal radiotherapy in children: Electron- or photon-based technique of spinal irradiation

    International Nuclear Information System (INIS)

    Chojnacka, M.; Skowronska-Gardas, A.; Pedziwiatr, K.; Morawska-Kaczynska, M.; Zygmuntowicz-Pietka, A.; Semaniak, A.

    2010-01-01

    Background: The prone position and electron-based technique for craniospinal irradiation (CSI) have been standard in our department for many years. But this immobilization is difficult for the anaesthesiologist to gain airway access. The increasing number of children treated under anaesthesia led us to reconsider our technique. Aim: The purpose of this study is to report our new photon-based technique for CSI which could be applied in both the supine and the prone position and to compare this technique with our electron-based technique. Materials and methods: Between November 2007 and May 2008, 11 children with brain tumours were treated in the prone position with CSI. For 9 patients two treatment plans were created: the first one using photons and the second one using electron beams for spinal irradiation. We prepared seven 3D-conformal photon plans and four forward planned segmented field plans. We compared 20 treatment plans in terms of target dose homogeneity and sparing of organs at risk. Results: In segmented field plans better dose homogeneity in the thecal sac volume was achieved than in electron-based plans. Regarding doses in organs at risk, in photon-based plans we obtained a lower dose in the thyroid but a higher one in the heart and liver. Conclusions: Our technique can be applied in both the supine and prone position and it seems to be more feasible and precise than the electron technique. However, more homogeneous target coverage and higher precision of dose delivery for photons are obtained at the cost of slightly higher doses to the heart and liver. (authors)

  3. [Significance of bone mineral density and modern cementing technique for in vitro cement penetration in total shoulder arthroplasty].

    Science.gov (United States)

    Pape, G; Raiss, P; Kleinschmidt, K; Schuld, C; Mohr, G; Loew, M; Rickert, M

    2010-12-01

    Loosening of the glenoid component is one of the major causes of failure in total shoulder arthroplasty. Possible risk factors for loosening of cemented components include an eccentric loading, poor bone quality, inadequate cementing technique and insufficient cement penetration. The application of a modern cementing technique has become an established procedure in total hip arthroplasty. The goal of modern cementing techniques in general is to improve the cement-penetration into the cancellous bone. Modern cementing techniques include the cement vacuum-mixing technique, retrograde filling of the cement under pressurisation and the use of a pulsatile lavage system. The main purpose of this study was to analyse cement penetration into the glenoid bone by using modern cement techniques and to investigate the relationship between the bone mineral density (BMD) and the cement penetration. Furthermore we measured the temperature at the glenoid surface before and after jet-lavage of different patients during total shoulder arthroplasty. It is known that the surrounding temperature of the bone has an effect on the polymerisation of the cement. Data from this experiment provide the temperature setting for the in-vitro study. The glenoid surface temperature was measured in 10 patients with a hand-held non-contact temperature measurement device. The bone mineral density was measured by DEXA. Eight paired cadaver scapulae were allocated (n = 16). Each pair comprised two scapulae from one donor (matched-pair design). Two different glenoid components were used, one with pegs and the other with a keel. The glenoids for the in-vitro study were prepared with the bone compaction technique by the same surgeon in all cases. Pulsatile lavage was used to clean the glenoid of blood and bone fragments. Low viscosity bone cement was applied retrogradely into the glenoid by using a syringe. A constant pressure was applied with a modified force sensor impactor. Micro-computed tomography

  4. Complications of surgery for radiotherapy skin damage

    International Nuclear Information System (INIS)

    Rudolph, R.

    1982-01-01

    Complications of modern surgery for radiotherapy skin damage reviewed in 28 patients who had 42 operations. Thin split-thickness skin grafts for ulcer treatment had a 100 percent complication rate, defined as the need for further surgery. Local flaps, whether delayed or not, also had a high rate of complications. Myocutaneous flaps for ulcers had a 43 percent complication rate, with viable flaps lifting off radiated wound beds. Only myocutaneous flaps for breast reconstruction and omental flaps with skin grafts and Marlex mesh had no complications. The deeper tissue penetration of modern radiotherapy techniques may make skin grafts and flaps less useful. In reconstruction of radiation ulcers, omental flaps and myocutaneous flaps are especially useful, particularly if the radiation damage can be fully excised. The pull of gravity appears detrimental to myocutaneous flap healing and, if possible, should be avoided by flap design

  5. Radiotherapy. 2. rev. ed.

    International Nuclear Information System (INIS)

    Wannenmacher, Michael; Debus, Juergen; Wenz, Frederik

    2013-01-01

    The purpose of this medical specialty book, besides presenting the state of the art in clinical radiotherapy and radiooncology, is to explain the basic principles of medical physics and radiobiology. Following a number of chapters on general topics and theory it provides detailed coverage of the individual organ systems, briefly addressing future aspects in the process. The authors relate their view that radiooncology as a medical specialty will continue to be under pressure to change and that it will take continuous innovation to secure its status within the interdisciplinary context around the treatment of cancer patients. The authors of this, the textbook's second edition, have dedicated much space to modern methods and techniques in order to do justice to these developments.

  6. Intensity modulated radiotherapy (IMRT) for patients of the Brazilian unified health system (SUS): an analysis of 508 treatments two years after the technique implementation

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Harley Francisco de; Trevisan, Felipe Amstalden; Bighetti, Viviane Marques; Guimaraes, Flavio da Silva; Amaral, Leonardo Lira; Barbi, Gustavo Lazaro; Borges, Leandro Federiche; Peria, Fernanda Maris, E-mail: harley@fmrp.usp.br [Universidade de Sao Paulo (FMRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina

    2014-11-15

    Objective: the offering of high-technology radiotherapy to the population assisted by the Brazilian unified health system (SUS) is limited since it is not included in the system’s list of procedures and, many times, because of the insufficient installed capacity and lack of specialized human resources. Thus the access to intensity-modulated radiotherapy (IMRT) is restricted to few centers in Brazil. The present study is aimed at presenting the characteristics of the first 508 cases treated with IMRT during the first years after the technique implementation in a university hospital. Materials and methods: the first consecutive 508 cases of IMRT treatment completed in the period from May/2011 to September/2013 were reviewed. Static multi leaf was the technique employed. Results: amongst 4,233 treated patients, 12.5% were submitted to IMRT. Main indications for the treatment included cancers located in the skull, head and neck and prostate. Intensity modulated radiotherapy was utilized in about 30% of cranial and 50% of prostate treatments. Treatment toxicity was observed in 4% of the patients. Conclusion: because of restricted access to radiotherapy in addition to lack of coverage for the procedure, IMRT indications for SUS patients should be based on institutional clinical protocols, with special attention to the reduction of toxicity. (author)

  7. Osteosynthesis techniques used for mandibular sagittal split osteotomy – history of orthognathic procedures and modern practice.

    Science.gov (United States)

    Nowak, Rafał; Trybek, Grzegorz

    Choosing an appropriate fixation technique after maxillary or mandibular osteotomy is one of the key factors affecting the success of orthognathic surgery. In line with the development of new surgical methods and techniques, the surgeons’ approach to the fixation of bone fragments has evolved accordingly, varying from non-fusion to different osteosynthesis techniques. Advances in medical sciences and medical technologies, have changed our attitudes to bone fragment reduction in orthopaedics and traumatology, and also in maxillofacial surgery. The pivotal underlying principle which determines bone healing – that is proper positioning so as to ensure appropriate contact area and immobilisation so as to ensure osteosynthesis – has remained unchanged for centuries. However, over the years, patient comfort and the predictability of treatment outcomes have vastly improved. The paper provides an overview of the techniques and methods used for the fixation of osteotomized fragments after bilateral sagittal split osteotomy since its introduction by Hugo Obwegeser up to the present day.

  8. MOSFET dosimetry on modern radiation oncology modalities

    International Nuclear Information System (INIS)

    Rosenfeld, A.B.

    2002-01-01

    The development of MOSFET dosimetry is presented with an emphasis on the development of a scanning MOSFET dosimetry system for modern radiation oncology modalities. Fundamental aspects of MOSFETs in relation to their use as dosemeters are briefly discussed. The performance of MOSFET dosemeters in conformal radiotherapy, hadron therapy, intensity-modulated radiotherapy and microbeam radiation therapy is compared with other dosimetric techniques. In particular the application of MOSFET dosemeters in the characterisation and quality assurance of the steep dose gradients associated with the penumbra of some modern radiation oncology modalities is investigated. A new in vivo, on-line, scanning MOSFET read out system is also presented. The system has the ability to read out multiple MOSFET dosemeters with excellent spatial resolution and temperature stability and minimal slow border trapping effects. (author)

  9. Postprostatectomy ultrasound-guided transrectal implantation of gold markers for external beam radiotherapy. Technique and complications rate

    Energy Technology Data Exchange (ETDEWEB)

    Langenhuijsen, J.F.; Kiemeney, L.A.L.M.; Witjes, J.A. [Radboud Univ. Nijmegen Medical Center, Nijmegen (Netherlands). Dept. of Urology; Donker, R. [Medical Center Alkmaar (Netherlands). Dept. of Radiation Oncology; McColl, G.M.; Lin, E.N.J.T. van [Radboud Univ. Nijmegen Medical Center, Nijmegen (Netherlands). Dept. of Radiation Oncology

    2013-06-15

    Background and purpose: Postprostatectomy radiotherapy (RT) improves survival in adjuvant and salvage settings. The implantation technique and complications rate of gold markers in the prostate bed for high-precision RT were analyzed. Patients and methods: Patients undergoing postprostatectomy RT for prostate-specific antigen (PSA) relapse or high-risk disease were enrolled in the study. Under transrectal ultrasound guidance, three fine gold markers were implanted in the prostate bed and the technical difficulties of insertion were documented. Patients received our self-designed questionnaires concerning complications and pain. The influence of anticoagulants and coumarins on bleeding was analyzed, as was the effect of potential risk factors on pain. Results: In 77 consecutive patients, failure of marker implantation or marker migration was seen in six cases. Rectal bleeding was reported by 10 patients and 1 had voiding complaints. No macroscopic hematuria persisting for more than 3 days was observed. Other complications included rectal discomfort (n = 2), nausea (n = 1), abdominal discomfort (n = 1), and pain requiring analgesics (n = 4). No major complications were reported. On a 0-10 visual analogue scale (VAS), the mean pain score was 3.7. No clinically significant risk factors for complications were identified. Conclusion: Transrectal implantation of gold markers in the prostate bed is feasible and safe. Alternatives like cone beam computed tomography (CBCT) should be considered, but the advantages of gold marker implantation for high-precision postprostatectomy RT would seem to outweigh the minor risks involved. (orig.)

  10. Use of image processing techniques to assess effect of disodium pamidronate in conjunction with radiotherapy in patients with bone metastases

    International Nuclear Information System (INIS)

    Kouloulias, Vassilios E.; Dardoufas, Costas E.; Kouvaris, John R.; Antypas, Christos E.; Sandilos, Panagiotis H.; Matsopoulos, George K.; Vlahos, Lambros J.

    2002-01-01

    The aim of this study was radiographically to monitor the effect of disodium pamidronate on metastatic bone disease, using image-processing techniques. Eighteen patients with osteolytic metastases from breast cancer received an intravenous infusion of 180 mg disodium pamidronate every 4 weeks for a period of 6 months. The first session of intravenous infusions was given concurrently with external beam radiotherapy with a 6 MV linear accelerator (total dose 30 Gy in 10 fractions). Radiographs of osteolytic lesions were obtained at every session of the treatment, retaining the same settings for each modality. The analysis of the attributes of the images was based on measuring the first-order statistics of the gray-level histogram in terms of mean value (MVGLH) and energy (EGLH). The measurements showed significant differences for MVGLH and EGLH values (p<0.05, Wilcoxon test). Analytically, there was an 11.08% (95% CI=10.21, 11.93) mean reduction of EGLH and an 11.63% (95% CI=10.96, 12.29) mean increase of MVGLH of the x-ray images, before and after the combined treatment protocol. The changes in the image-processing indices were also highly correlated with the reduction of the patient's pain score. These findings indicate an important increase in bone mass and bone formation, which the radiologists found difficult to identify visually

  11. Use of image processing techniques to assess effect of disodium pamidronate in conjunction with radiotherapy in patients with bone metastases

    Energy Technology Data Exchange (ETDEWEB)

    Kouloulias, Vassilios E.; Dardoufas, Costas E.; Kouvaris, John R.; Antypas, Christos E.; Sandilos, Panagiotis H.; Matsopoulos, George K.; Vlahos, Lambros J. [Areteion Univ. Hospital Athens (Greece). Radiotherapy Dept.

    2002-04-01

    The aim of this study was radiographically to monitor the effect of disodium pamidronate on metastatic bone disease, using image-processing techniques. Eighteen patients with osteolytic metastases from breast cancer received an intravenous infusion of 180 mg disodium pamidronate every 4 weeks for a period of 6 months. The first session of intravenous infusions was given concurrently with external beam radiotherapy with a 6 MV linear accelerator (total dose 30 Gy in 10 fractions). Radiographs of osteolytic lesions were obtained at every session of the treatment, retaining the same settings for each modality. The analysis of the attributes of the images was based on measuring the first-order statistics of the gray-level histogram in terms of mean value (MVGLH) and energy (EGLH). The measurements showed significant differences for MVGLH and EGLH values (p<0.05, Wilcoxon test). Analytically, there was an 11.08% (95% CI=10.21, 11.93) mean reduction of EGLH and an 11.63% (95% CI=10.96, 12.29) mean increase of MVGLH of the x-ray images, before and after the combined treatment protocol. The changes in the image-processing indices were also highly correlated with the reduction of the patient's pain score. These findings indicate an important increase in bone mass and bone formation, which the radiologists found difficult to identify visually.

  12. Monitoring translocations by M-FISH and three-color FISH painting techniques. A study of two radiotherapy patients

    International Nuclear Information System (INIS)

    Pouzoulet, F.; Roch-Lefevre, S.; Giraudet, AL.

    2007-01-01

    To compare translocation rate using either M-FISH or FISH-3 in two patients treated for head and neck cancer, with a view to retrospective dosimetry. Translocation analysis was performed on peripheral blood lymphocyte cultures from blood samples taken at different times during the radiotherapy (0 Gy, 12 Gy and 50 Gy) and a few months after the end of the treatment (follow-up). Estimated translocation yield varied according to the FISH technique used. At 50 Gy and follow-up points, the translocation yields were higher with FISH-3 than with M-FISH. This difference can be attributed to three events. First, an increase in complex aberrations was observed for 50 Gy and follow-up points compared with 0 Gy and 12 Gy points. Second, at the end of treatment for patient A, involvement of chromosomes 2, 4, 12 in translocations was less than expected according to the Lucas formula. Third, a clone bearing a translocation involving a FISH-3 painted chromosome was detected. More translocations were detected with M-FISH than with FISH-3, and so M-FISH is expected to improve the accuracy of chromosome aberration analyses in some situations. (author)

  13. Development of the techniques of radiotherapy of lung cancer in the republic of belarus (1970-1995)

    International Nuclear Information System (INIS)

    Muravskaya, G.V.; Artemova, N.A.; Golub, G.D.; Krutilina, N.I.; Minajlo, I.I.; Sinajko, V.V.; Suravikina, V.V.; Ulitskij, P.I.

    1996-01-01

    A 25-year (1970-1995) experience in clinical employment of original and improved techniques of radiation treatment in the management of more than 12,000 lung cancer patients is assessed. The employment of the new methods of radiotherapy of operable stage III squamous-cell lung cancer patients increased their 5-year survival rate from 8±3% to 42±5%, and that of inoperable stage II-III patients - from 5 to 9%. An original method of chemoradiotherapy of stage II-III small-cell cancer enabled to raise 5-year survival rate from 4 to 12%. Owing to the reduction in the number of patients declining special treatment (from 32 to 13.7%) and widening the range of indications to treatment (from 65 to 83%) the rate of clinical group II lung cancer patients administered special treatment rose more than twice (from 32.4 to 69.3%) over the past 15 years. The proportion of lung cancer patients among all cancer patients being on the register for more than 5 years in the Republic of Belarus increased more than 3-fold (from 8 to 26.7%) over the past 20 years

  14. Use of Modern Chemical Protein Synthesis and Advanced Fluorescent Assay Techniques to Experimentally Validate the Functional Annotation of Microbial Genomes

    Energy Technology Data Exchange (ETDEWEB)

    Kent, Stephen [University of Chicago

    2012-07-20

    The objective of this research program was to prototype methods for the chemical synthesis of predicted protein molecules in annotated microbial genomes. High throughput chemical methods were to be used to make large numbers of predicted proteins and protein domains, based on microbial genome sequences. Microscale chemical synthesis methods for the parallel preparation of peptide-thioester building blocks were developed; these peptide segments are used for the parallel chemical synthesis of proteins and protein domains. Ultimately, it is envisaged that these synthetic molecules would be ‘printed’ in spatially addressable arrays. The unique ability of total synthesis to precision label protein molecules with dyes and with chemical or biochemical ‘tags’ can be used to facilitate novel assay technologies adapted from state-of-the art single molecule fluorescence detection techniques. In the future, in conjunction with modern laboratory automation this integrated set of techniques will enable high throughput experimental validation of the functional annotation of microbial genomes.

  15. Dosimetric study of the different techniques to deal with respiratory motion for lung stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Paumier, A.; Krhili, S.; Georgin-Mege, M.; Tuchais, C.; Cellier, P.; Crespeau, A.; Mesgouez, J.; Autret, D.; Lisbona, A.; Denis, F.

    2012-01-01

    Purpose. - To evaluate the different respiratory movement management techniques during irradiation of lung tumours. Patients and methods. - Seven patients with one or more primary or secondary lung lesions less than 5 cm (11 tumours in total) had three computed tomographies (CT): free-breathing, deep-inspiration breath hold using a spirometer, and 4-dimensional (4D). From these three acquisitions, five treatment plans were performed: free-breathing (reference method), deep-inspiration breath-hold, and three from the 4D CT: two breathing synchronized treatments (inspiration and expiration) and one treatment taking into account all the tumour motions (definition of the internal target volume [ITV]). Planning target volume (PTV) size and dose delivered to the lungs were compared. Results. - Mean PTV with the free-breathing modality was 83±28 cm 3 , which was significantly greater than any of the other techniques (P 3 ), and PTV with the deep-inspiration breath-hold, breathing synchronized inspiration and breathing synchronized expiration techniques were reduced by one third (50 to 54±24 to 26 cm 3 ). Deep-inspiration led to significantly increase the healthy lung volume compared to other methods (mean volume of 5500±1500 cm 3 versus 3540 to 3920 cm 3 , respectively, P < 0.0001). The volume of healthy lungs receiving at least 5 and 20 Gy (V5 and V5) were significantly higher with the free-breathing method than any of the other methods (P < 0.0001). The deep-inspiration breath-hold modality led to the lowest lung V5 and V20. Conclusion. - Deep-inspiration breath-hold technique provides the most significant dosimetric advantages: small PTV and large lung volume. However, patients must be able to hold 20 seconds of apnea. Respiratory gating also reduces the PTV, but its application often requires the implantation of fiducial, which limit its use. A 4-dimensional CT allows for a personalized and reduced PTV compared to free-breathing CT. (authors)

  16. Intensity-modulated radiotherapy with simultaneous modulated accelerated boost technique and chemotherapy in patients with nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Fareed, Muhammad M; AlAmro, Abdullah S; Bayoumi, Yasser; Tunio, Mutahir A; Ismail, Abdul S; Akasha, Rashad; Mubasher, Mohamed; Al Asiri, Mushabbab

    2013-01-01

    To present our experience of intensity-modulated radiotherapy (IMRT) with simultaneous modulated accelerated radiotherapy (SMART) boost technique in patients with nasopharyngeal carcinoma (NPC). Sixty eight patients of NPC were treated between April 2006 and December 2011 including 45 males and 23 females with mean age of 46 (range 15–78). Stage distribution was; stage I 3, stage II 7, stage III 26 and stage IV 32. Among 45 (66.2%) evaluated patients for presence of Epstein-Barr virus (EBV), 40 (88.8%) were positive for EBV. Median radiation doses delivered to gross tumor volume (GTV) and positive neck nodes were 66–70 Gy, 63 Gy to clinical target volume (CTV) and 50.4 Gy to clinically negative neck. In addition 56 (82.4%) patients with bulky tumors (T4/N2+) received neoadjuvant chemotherapy 2–3 cycles (Cisplatin/Docetaxel or Cisplatin/Epirubicin or Cisplatin/5 Flourouracil). Concurrent chemotherapy with radiation was weekly Cisplatin 40 mg/m 2 (40 patients) or Cisplatin 100 mg/m 2 (28 patients). With a median follow up of 20 months (range 3–43), one patient developed local recurrence, two experienced regional recurrences and distant failure was seen in 3 patients. Estimated 3 year disease free survival (DFS) was 94%. Three year DFS for patients with EBV was 100% as compared to 60% without EBV (p = 0.0009). Three year DFS for patients with undifferentiated histology was 98% as compared to 82% with other histologies (p = 0.02). Acute grade 3 toxicity was seen as 21 (30.9%) having G-III mucositis and 6 (8.8%) with G-III skin reactions. Late toxicity was minimal and loss of taste was seen in 3 patients (7.5%) at time of analysis. IMRT with SMART in combination with chemotherapy is feasible and effective in terms of both the clinical response and safety profile. EBV, histopathology and nodal involvement were found important prognostic factors for locoregional recurrence

  17. Modern techniques for the analysis of chromatin and nuclear organization in C. elegans.

    Science.gov (United States)

    Askjaer, Peter; Ercan, Sevinç; Meister, Peter

    2014-04-02

    In recent years, Caenorhabditis elegans has emerged as a new model to investigate the relationships between nuclear architecture, cellular differentiation, and organismal development. On one hand, C. elegans with its fixed lineage and transparent body is a great model organism to observe gene functions in vivo in specific cell types using microscopy. On the other hand, two different techniques have been applied in nematodes to identify binding sites for chromatin-associated proteins genome-wide: chromatin immunoprecipitation (ChIP), and Dam-mediated identification (DamID). We summarize here all three techniques together as they are complementary. We also highlight strengths and differences of the individual approaches.

  18. Role of modern analytical techniques in the production of uranium metal

    International Nuclear Information System (INIS)

    Hareendran, K.N.; Roy, S.B.

    2009-01-01

    Production of nuclear grade uranium metal conforming to its stringent specification with respect to metallic and non metallic impurities necessitates implementation of a comprehensive quality control regime. Founding members of Uranium Metal Plant realised the importance of this aspect of metal production and a quality control laboratory was set up as part of the production plant. In the initial stages of its existence, the laboratory mainly catered to the process control analysis of the plant process samples and Spectroscopy Division and Analytical Division of BARC provided analysis of trace metallic impurities in the intermediates as well as in the product uranium metal. This laboratory also provided invaluable R and D support for the optimization of the process involving both calciothermy and magnesiothermy. Prior to 1985, analytical procedures used were limited to classical methods of analysis with minimal instrumental procedures. The first major analytical instrument, a Flame AAS was installed in 1985 and a beginning to the trace analysis was made. However during the last 15 years the Quality Control Section has modernized the analytical set up by acquiring appropriate instruments. Presently the facility has implemented a complete quality control and quality assurance program required to cover all aspects of uranium metal production viz analysis of raw materials, process samples, waste disposal samples and also determination of all the specification elements in uranium metal. The current analytical practices followed in QCS are presented here

  19. AMS-14C analysis of modern teeth: A comparison between two sample preparation techniques

    Science.gov (United States)

    Solis, C.; Solis-Meza, E.; Morales, M. E.; Rodriguez-Ceja, M.; Martínez-Carrillo, M. A.; Garcia-Calderon, D.; Huerta, A.; Chávez, E.

    2017-09-01

    AMS-14C analysis of modern teeth has become important for forensic studies. 14C content in human teeth reflects the 14C atmospheric concentration during its formation and allows the calculation of the actual year of birth. Through AMS, it is possible to measure the 14C concentrations in a tissue with high precision. However, there is a debate about which should be the best fraction for teeth carbon dating: collagen or enamel. This work focuses on the results obtained from enamel and collagen extracted from Mexican people in order to compare them. Collagen from dental pieces donated from people older than 60-years-old have been included to understand the turnover process and usefulness of collagen to determine the date of birth. Our results indicate that when a single dental piece is available, enamel method allows the determination of the tooth formation date. Dating collagen of the same tooth helps to discriminate if the formation date belongs to the left or the right side of the peak bomb, but also corroborates, the ages obtained through enamel analysis.

  20. The role of graphene-based sorbents in modern sample preparation techniques.

    Science.gov (United States)

    de Toffoli, Ana Lúcia; Maciel, Edvaldo Vasconcelos Soares; Fumes, Bruno Henrique; Lanças, Fernando Mauro

    2018-01-01

    The application of graphene-based sorbents in sample preparation techniques has increased significantly since 2011. These materials have good physicochemical properties to be used as sorbent and have shown excellent results in different sample preparation techniques. Graphene and its precursor graphene oxide have been considered to be good candidates to improve the extraction and concentration of different classes of target compounds (e.g., parabens, polycyclic aromatic hydrocarbon, pyrethroids, triazines, and so on) present in complex matrices. Its applications have been employed during the analysis of different matrices (e.g., environmental, biological and food). In this review, we highlight the most important characteristics of graphene-based material, their properties, synthesis routes, and the most important applications in both off-line and on-line sample preparation techniques. The discussion of the off-line approaches includes methods derived from conventional solid-phase extraction focusing on the miniaturized magnetic and dispersive modes. The modes of microextraction techniques called stir bar sorptive extraction, solid phase microextraction, and microextraction by packed sorbent are discussed. The on-line approaches focus on the use of graphene-based material mainly in on-line solid phase extraction, its variation called in-tube solid-phase microextraction, and on-line microdialysis systems. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Dysphagia Screening: Contributions of Cervical Auscultation Signals and Modern Signal-Processing Techniques

    Science.gov (United States)

    Dudik, Joshua M.; Coyle, James L.

    2015-01-01

    Cervical auscultation is the recording of sounds and vibrations caused by the human body from the throat during swallowing. While traditionally done by a trained clinician with a stethoscope, much work has been put towards developing more sensitive and clinically useful methods to characterize the data obtained with this technique. The eventual goal of the field is to improve the effectiveness of screening algorithms designed to predict the risk that swallowing disorders pose to individual patients’ health and safety. This paper provides an overview of these signal processing techniques and summarizes recent advances made with digital transducers in hopes of organizing the highly varied research on cervical auscultation. It investigates where on the body these transducers are placed in order to record a signal as well as the collection of analog and digital filtering techniques used to further improve the signal quality. It also presents the wide array of methods and features used to characterize these signals, ranging from simply counting the number of swallows that occur over a period of time to calculating various descriptive features in the time, frequency, and phase space domains. Finally, this paper presents the algorithms that have been used to classify this data into ‘normal’ and ‘abnormal’ categories. Both linear as well as non-linear techniques are presented in this regard. PMID:26213659

  2. Overuse of trauma in sports - clinical signs in the context with modern imaging techniques

    International Nuclear Information System (INIS)

    Wurnig, C.; Gollob, E.

    2001-01-01

    New insights in the fields of pathology and diagnostic radiology of sports injuries show that the borders between overuse syndromes and trauma are blurred. Techniques of diagnostic imaging are increasingly important for an objective documentation of morphologic changes of the musculoskeletal system. Typical sports-related syndromes exist and their clinical diagnosis is not always easy because pain cannot be located exactly. (author)

  3. A technique of using gated-CT images to determine internal target volume (ITV) for fractionated stereotactic lung radiotherapy

    International Nuclear Information System (INIS)

    Jin Jianyue; Ajlouni, Munther; Chen Qing; Yin, Fang-Fang; Movsas, Benjamin

    2006-01-01

    Background and purpose: To develop and evaluate a technique and procedure of using gated-CT images in combination with PET image to determine the internal target volume (ITV), which could reduce the planning target volume (PTV) with adequate target coverage. Patients and methods: A skin marker-based gating system connected to a regular single slice CT scanner was used for this study. A motion phantom with adjustable motion amplitude was used to evaluate the CT gating system. Specifically, objects of various sizes/shapes, considered as virtual tumors, were placed on the phantom to evaluate the number of phases of gated images required to determine the ITV while taking into account tumor size, shape and motion. A procedure of using gated-CT and PET images to define ITV for patients was developed and was tested in patients enrolled in an IRB approved protocol. Results: The CT gating system was capable of removing motion artifacts for target motion as large as 3-cm when it was gated at optimal phases. A phantom study showed that two gated-CT scans at the end of expiration and the end of inspiration would be sufficient to determine the ITV for tumor motion less than 1-cm, and another mid-phase scan would be required for tumors with 2-cm motion, especially for small tumors. For patients, the ITV encompassing visible tumors in all sets of gated-CT and regular spiral CT images seemed to be consistent with the target volume determined from PET images. PTV expanded from the ITV with a setup uncertainty margin had less volume than PTVs from spiral CT images with a 10-mm generalized margin or an individualized margin determined at fluoroscopy. Conclusions: A technique of determining the ITV using gated-CT images was developed and was clinically implemented successfully for fractionated stereotactic lung radiotherapy

  4. Half-body radiotherapy. Evaluation of the technique in normal dogs

    International Nuclear Information System (INIS)

    Laing, E.J.; Fitzpatrick, P.J.; Norris, A.M.; Mosseri, A.; Rider, W.D.; Binnington, A.G.; Baur, A.; Valli, V.E.

    1989-01-01

    Eight healthy mongrel dogs were treated with half-body irradiation (HBI) in a pilot study to evaluate the technique and radiotolerance of different organs. Cranial and caudal half-body fields were established using the 13th thoracic vertebra as the dividing point. Under general anesthesia, either 7 or 8 Gray (Gy) were delivered to one half of the body using opposing radiation portals. The other half of the body was similarly treated 28 days later. The dogs were monitored for 12 months. Significant radiation effects included transient bone marrow suppression and radiation sickness. There were no serious or life-threatening problems, but the 8 Gy group consistently showed more severe clinical signs and histologic changes than the 7 Gy group. Total body irradiation in two fractions of 7 or 8 Gy given 1 month apart appears to be a safe treatment that can be developed for therapy in veterinary oncology

  5. Technique of radiotherapy of the neurocranium in children suffering from leucosis

    Energy Technology Data Exchange (ETDEWEB)

    Thiel, H.J.

    1985-11-01

    By an irradiation of the neurocranium with doses from 12 to 30 Gy during the combined treatment of ALL in children, an essential reduction of the leukemic manifestation on the meninges as well as an improved curability have been achieved during the last few years. The precision of the irradiation technique is of vital importance, i.e. the occurrence of recurrences on the central nervous system during complete remission after skull irradiation are preponderantly due to a defective irradiation technique. The important factors are a daily reproducible positioning and fixation of the head in an irradiation mask and the adjustment within three dimensions by means of a laser light system. Only cobalt-60 gamma radiation or the ultrahard photons of a linear accelerator with an energy of 4 to 6 MV should be applied. The irradiation is performed with laterally opposite, coplanar and coaxial fields in an isocentric adjustment. The field shape is regulated by individual absorbers adjusted under visual control in a defined position to the patient on a plexiglas plate at the therapy simulator. In order to guarantee an homogeneic dose also to the meninges situated at the field borders and to prevent a ''geographic miss'', the field borders should exceed the cranial calotte by 1 to 2 cm at the frontal, vertical and occipital side. At the base of the skull, special consideration must be given to a sufficient irradiation of the retrobulbar spaces, the frontal meninges situated in the region of the lamina cribrosa and the temporal meninges situated in the region of the deep inner cranial fossae. The dose specification is made in the central ray in the center of the skull. Generally single doses of 2 Gy and weekly doses of 10 Gy are applied. The total dose depends on age, risk group, and treatment aim. (orig./WU).

  6. Technique of radiotherapy of the neurocranium in children suffering from leucosis

    International Nuclear Information System (INIS)

    Thiel, H.J.

    1985-01-01

    By an irradiation of the neurocranium with doses from 12 to 30 Gy during the combined treatment of ALL in children, an essential reduction of the leukemic manifestation on the meninges as well as an improved curability have been achieved during the last few years. The precision of the irradiation technique is of vital importance, i.e. the occurrence of recurrences on the central nervous system during complete remission after skull irradiation are preponderantly due to a defective irradiation technique. The important factors are a daily reproducible positioning and fixation of the head in an irradiation mask and the adjustment within three dimensions by means of a laser light system. Only cobalt-60 gamma radiation or the ultrahard photons of a linear accelerator with an energy of 4 to 6 MV should be applied. The irradiation is performed with laterally opposite, coplanar and coaxial fields in an isocentric adjustment. The field shape is regulated by individual absorbers adjusted under visual control in a defined position to the patient on a plexiglas plate at the therapy simulator. In order to guarantee an homogeneic dose also to the meninges situated at the field borders and to prevent a ''geographic miss'', the field borders should exceed the cranial calotte by 1 to 2 cm at the frontal, vertical and occipital side. At the base of the skull, special consideration must be given to a sufficient irradiation of the retrobulbar spaces, the frontal meninges situated in the region of the lamina cribrosa and the temporal meninges situated in the region of the deep inner cranial fossae. The dose specification is made in the central ray in the center of the skull. Generally single doses of 2 Gy and weekly doses of 10 Gy are applied. The total dose depends on age, risk group, and treatment aim. (orig./WU) [de

  7. Dosimetry applied to radiology and radiotherapy

    International Nuclear Information System (INIS)

    Yoshimura, Elisabeth Mateus

    2010-01-01

    Full text. The uses of ionizing radiation in medicine are increasing worldwide, and the population doses increase as well. The actual radiation protection philosophy is based on the balance of risks and benefits related to the practices, and patient dosimetry has an important role in the implementation of this point of view. In radiology the goal is to obtain an image with diagnostic quality with the minimum patient dose. In modern Radiotherapy the cure indexes are higher, giving rise to longer survival times to the patients. Dosimetry in radiotherapy helps the treatment planning systems to get a better protection to critical organs, with higher doses to the tumor, with a guarantee of better life quality to the patient. We will talk about the new trends in dosimetry of medical procedures, including experimental techniques and calculation tools developed to increase reliability and precision of dose determination. In radiology the main concerns of dosimetry are: the transition from film- radiography to digital image, the pediatric patient doses, and the choice of dosimetric quantities to quantify fluoroscopy and tomography patient doses. As far as Radiotherapy is concerned, there is a search for good experimental techniques to quantify doses to tissues adjacent to the target volumes in patients treated with new radiotherapy techniques, as IMRT and heavy particle therapy. (author)

  8. A review of modern instrumental techniques for measurements of ice cream characteristics.

    Science.gov (United States)

    Bahram-Parvar, Maryam

    2015-12-01

    There is an increasing demand of the food industries and research institutes to have means of measurement allowing the characterization of foods. Ice cream, as a complex food system, consists of a frozen matrix containing air bubbles, fat globules, ice crystals, and an unfrozen serum phase. Some deficiencies in conventional methods for testing this product encourage the use of alternative techniques such as rheometry, spectroscopy, X-ray, electro-analytical techniques, ultrasound, and laser. Despite the development of novel instrumental applications in food science, use of some of them in ice cream testing is few, but has shown promising results. Developing the novel methods should increase our understanding of characteristics of ice cream and may allow online testing of the product. This review article discusses the potential of destructive and non-destructive methodologies in determining the quality and characteristics of ice cream and similar products. Copyright © 2015. Published by Elsevier Ltd.

  9. Comparison and analysis of two modern methods in the structural health monitoring techniques in aerospace

    Science.gov (United States)

    Riahi, Mohammad; Ahmadi, Alireza

    2016-04-01

    Role of air transport in the development and expansion of world trade leading to economic growth of different countries is undeniable. Continuing the world's trade sustainability without expansion of aerospace is next to impossible. Based on enormous expenses for design, manufacturing and maintenance of different aerospace structures, correct and timely diagnosis of defects in those structures to provide for maximum safety has the highest importance. Amid all this, manufacturers of commercial and even military aircrafts are after production of less expensive, lighter, higher fuel economy and nonetheless, higher safety. As such, two events has prevailed in the aerospace industries: (1) Utilization of composites for the fuselage as well as other airplane parts, (2) using modern manufacturing methods. Arrival of two these points have created the need for upgrading of the present systems as well as innovating newer methods in diagnosing and detection of defects in aerospace structures. Despite applicability of nondestructive testing (NDT) methods in aerospace for decades, due to some limitations in the defect detection's certainty, particularly for composite material and complex geometries, shadow of doubt has fallen on maintaining complete confidence in using NDT. These days, two principal approach are ahead to tackle the above mentioned problems. First, approach for the short range is the creative and combinational mean to increase the reliability of NDT and for the long run, innovation of new methods on the basis of structural health monitoring (SHM) is in order. This has led to new philosophy in the maintenance area and in some instances; field of design has also been affected by it.

  10. Modern Hardware Technologies and Software Techniques for On-Line Database Storage and Access.

    Science.gov (United States)

    1985-12-01

    of the information in a message narrative. This method employs artificial intelligence techniques to extract information, In simalest terms, an...disf ribif ion (tape replacemenf) systemns Database distribution On-fine mass storage Videogame ROM (luke-box I Media Cost Mt $2-10/438 $10-SO/G38...trajninq ot tne great intelligence for the analyst would be required. If, on’ the other hand, a sentence analysis scneme siTole enouq,. for the low-level

  11. Next-Generation Environment-Aware Cellular Networks: Modern Green Techniques and Implementation Challenges

    KAUST Repository

    Ghazzai, Hakim

    2016-09-16

    Over the last decade, mobile communications have been witnessing a noteworthy increase of data traffic demand that is causing an enormous energy consumption in cellular networks. The reduction of their fossil fuel consumption in addition to the huge energy bills paid by mobile operators is considered as the most important challenges for the next-generation cellular networks. Although most of the proposed studies were focusing on individual physical layer power optimizations, there is a growing necessity to meet the green objective of fifth-generation cellular networks while respecting the user\\'s quality of service. This paper investigates four important techniques that could be exploited separately or together in order to enable wireless operators achieve significant economic benefits and environmental savings: 1) the base station sleeping strategy; 2) the optimized energy procurement from the smart grid; 3) the base station energy sharing; and 4) the green networking collaboration between competitive mobile operators. The presented simulation results measure the gain that could be obtained using these techniques compared with that of traditional scenarios. Finally, this paper discusses the issues and challenges related to the implementations of these techniques in real environments. © 2016 IEEE.

  12. The value of 18F-FDG PET in three-dimensional conformal radiotherapy of cancer

    International Nuclear Information System (INIS)

    Lv Huiqing; Zhang Zhongmin; Lv Zhonghong

    2006-01-01

    Three-dimensional conformal radiotherapy (3D-CRT) is based on an extensive use of modern medical imaging techniques. Delineation of the gross tumor volume and organs at risk constitutes one of the most important phases of conformal radiotherapy procedures. 18 F-fluorodeoxyglucose ( 18 F-FDG) PET possesses greater sensitivity and accuracy in detecting diseased lymph nodes, is an important staging examination for patients considered for radiation treatment with curative intent. 18 F-FDG PET has an important role in delineation of gross tumor volume for patients treated with three-dimensional conformal radiotherapy. (authors)

  13. Radiotherapy of degenerative joint disorders. Indication, technique and clinical results; Radiotherapie bei schmerzhaften degenerativ-entzuendlichen Gelenkerkrankungen. Indikation, Technik und klinische Ergebnisse

    Energy Technology Data Exchange (ETDEWEB)

    Keilholz, L.; Sauer, R. [Erlangen-Nuernberg Univ. (Germany). Strahlentherapeutische Klinik und Poliklinik; Seegenschmiedt, M.H. [Erlangen-Nuernberg Univ. (Germany). Strahlentherapeutische Klinik und Poliklinik]|[Alfred-Krupp-Krankenhaus, Essen (Germany). Klinik fuer Strahlentherapie und Radioonkologie

    1998-05-01

    From 1984 to 1994, 85 patients with painful osteoarthritis were treated. The mean follow-up was 4 (1 to 10) years. Seventy-three patients (103 joints) were available for long-term analysis: 17 patients (27 joints) with omarthrosis, 19 (20 joints) with rhizarthrosis, 31 (49 joints) with osteoarthritis of the knee and 6 patients (7 joints) with osteoarthritis of the hip. All patients were intensively pretreated over long time. Mean symptom duration prior to radiotherapy was 4 (1 to 10) years. Orthovoltage or linac photons were applied using some technical modifications depending upon the joint. Two radiotherapy series (6 x 1 Gy, total dose: 12 Gy, 3 weekly fractions) were prescribed. The interval between the 2 series was 6 weeks. The subjective pain profil was assessed prior to and 6 months after radiotherapy and at last follow-up. Forty-six (63%) patients (64 joints) achieved a reduction of pain symptoms; 16 of those had a `major pain relief` and 14 `complete pain relief`. Large joints - knee and hip - responded better (64% each) than the rhizarthrosis (53%). All pain categories and grades and their combined pain score were significantly reduced. The pain reduction was mostly pronounced for the symptom `pain at rest`. The orthopedic score correlated well with the subjective response of the patients. The thumb score improved in 11 (57%) joints, the shoulder score of Constant and Murley in 16 (59%), the Japonese knee score of Sasaki et al. in 33 (67%), the hip score of Harris in 5 (71%) joints. Only 9 of 19 patients which were treated to avoid surgery, had to be operated, and 3 of those received a total arthroplasty of the hip or knee. In multivariate analysis for the endpoint `complete` or `major pain relief` only the criterion `symptom duration {>=}2 years prior to radiotherapy` was an independent negative prognostic parameter. (orig./MG) [Deutsch] Von 1984 bis 1994 wurden 85 Patienten wegen schmerzhaft arthrotischer Gelenkerkrankungen bestrahlt. 73 Patienten (103

  14. Labelling techniques of biomolecules for targeted radiotherapy. Final report of a co-ordinated research project 1998-2002

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    Malignant tumour disease accounts for approximately one third of deaths worldwide. Gastrointestinal adenocarcinomas, prostate and breast cancers are among the most frequently appearing tumours. Radiotherapy is an essential mode of treatment of all cancer patients either alone or in conjunction with other modalities like surgery and chemotherapy. In most cases radiotherapy is given using external radiation sources. It is also possible to administer radiotherapy by specifically localizing radioisotopes emitting particulate radiation in the tumour tissue. This targeted therapy has proved to have several advantages over external beam therapy, notably the possibility of selectively delivering higher radiation doses to the targeted tumour cells and treating multiple metastases. Procedures for therapy of thyroid carcinoma and hyper-thyroidism using radioiodine (131I) introduced about five decades ago, have stood the test of time and are still widely used the world over. In addition to the therapeutic nuclides of the first generation 131I, 89Sr, 32P, 90Y, etc., which are still widely utilized and accepted by the medical community, many other beta emitting radionuclides with relatively short half-lives such as 153Sm, 186Re, 188Re, 166Ho, 165Dy, etc. have also been recently made available for therapy and used with promising good results. In spite of the potential of targeted radiotherapy to treat a wide range of malignant conditions, routine clinical use is mostly confined to therapy of thyroid carcinoma, hyperthyroidism, metastatic bone pain and synovectomy. In most of the cases, the limitation is obviously not the availability of suitable radionuclides but rather the lack of suitable carrier molecules that would adequately concentrate these radionuclides in target tissues of interest. Based on the above considerations, the scope of the Co-ordinated Research Project (CRP) has focused on the synthesis of the required BFCAs for MoAbs and peptide labelling, development and

  15. Labelling techniques of biomolecules for targeted radiotherapy. Final report of a co-ordinated research project 1998-2002

    International Nuclear Information System (INIS)

    2003-07-01

    Malignant tumour disease accounts for approximately one third of deaths worldwide. Gastrointestinal adenocarcinomas, prostate and breast cancers are among the most frequently appearing tumours. Radiotherapy is an essential mode of treatment of all cancer patients either alone or in conjunction with other modalities like surgery and chemotherapy. In most cases radiotherapy is given using external radiation sources. It is also possible to administer radiotherapy by specifically localizing radioisotopes emitting particulate radiation in the tumour tissue. This targeted therapy has proved to have several advantages over external beam therapy, notably the possibility of selectively delivering higher radiation doses to the targeted tumour cells and treating multiple metastases. Procedures for therapy of thyroid carcinoma and hyper-thyroidism using radioiodine (131I) introduced about five decades ago, have stood the test of time and are still widely used the world over. In addition to the therapeutic nuclides of the first generation 131I, 89Sr, 32P, 90Y, etc., which are still widely utilized and accepted by the medical community, many other beta emitting radionuclides with relatively short half-lives such as 153Sm, 186Re, 188Re, 166Ho, 165Dy, etc. have also been recently made available for therapy and used with promising good results. In spite of the potential of targeted radiotherapy to treat a wide range of malignant conditions, routine clinical use is mostly confined to therapy of thyroid carcinoma, hyperthyroidism, metastatic bone pain and synovectomy. In most of the cases, the limitation is obviously not the availability of suitable radionuclides but rather the lack of suitable carrier molecules that would adequately concentrate these radionuclides in target tissues of interest. Based on the above considerations, the scope of the Co-ordinated Research Project (CRP) has focused on the synthesis of the required BFCAs for MoAbs and peptide labelling, development and

  16. Pre-optimization of radiotherapy treatment planning: an artificial neural network classification aided technique

    International Nuclear Information System (INIS)

    Hosseini-Ashrafi, M.E.; Bagherebadian, H.; Yahaqi, E.

    1999-01-01

    A method has been developed which, by using the geometric information from treatment sample cases, selects from a given data set an initial treatment plan as a step for treatment plan optimization. The method uses an artificial neural network (ANN) classification technique to select a best matching plan from the 'optimized' ANN database. Separate back-propagation ANN classifiers were trained using 50, 60 and 77 examples for three groups of treatment case classes (up to 21 examples from each class were used). The performance of the classifiers in selecting the correct treatment class was tested using the leave-one-out method; the networks were optimized with respect their architecture. For the three groups used in this study, successful classification fractions of 0.83, 0.98 and 0.93 were achieved by the optimized ANN classifiers. The automated response of the ANN may be used to arrive at a pre-plan where many treatment parameters may be identified and therefore a significant reduction in the steps required to arrive at the optimum plan may be achieved. Treatment planning 'experience' and also results from lengthy calculations may be used for training the ANN. (author)

  17. A Morphing Technique Applied to Lung Motions in Radiotherapy: Preliminary Results

    Directory of Open Access Journals (Sweden)

    R. Laurent

    2010-01-01

    Full Text Available Organ motion leads to dosimetric uncertainties during a patient’s treatment. Much work has been done to quantify the dosimetric effects of lung movement during radiation treatment. There is a particular need for a good description and prediction of organ motion. To describe lung motion more precisely, we have examined the possibility of using a computer technique: a morphing algorithm. Morphing is an iterative method which consists of blending one image into another image. To evaluate the use of morphing, Four Dimensions Computed Tomography (4DCT acquisition of a patient was performed. The lungs were automatically segmented for different phases, and morphing was performed using the end-inspiration and the end-expiration phase scans only. Intermediate morphing files were compared with 4DCT intermediate images. The results showed good agreement between morphing images and 4DCT images: fewer than 2 % of the 512 by 256 voxels were wrongly classified as belonging/not belonging to a lung section. This paper presents preliminary results, and our morphing algorithm needs improvement. We can infer that morphing offers considerable advantages in terms of radiation protection of the patient during the diagnosis phase, handling of artifacts, definition of organ contours and description of organ motion.

  18. Adhesion, friction, wear, and lubrication research by modern surface science techniques.

    Science.gov (United States)

    Keller, D. V., Jr.

    1972-01-01

    The field of surface science has undergone intense revitalization with the introduction of low-energy electron diffraction, Auger electron spectroscopy, ellipsometry, and other surface analytical techniques which have been sophisticated within the last decade. These developments have permitted submono- and monolayer structure analysis as well as chemical identification and quantitative analysis. The application of a number of these techniques to the solution of problems in the fields of friction, lubrication, and wear are examined in detail for the particular case of iron; and in general to illustrate how the accumulation of pure data will contribute toward the establishment of physiochemical concepts which are required to understand the mechanisms that are operational in friction systems. In the case of iron, LEED, Auger and microcontact studies have established that hydrogen and light-saturated organic vapors do not establish interfaces which prevent iron from welding, whereas oxygen and some oxygen and sulfur compounds do reduce welding as well as the coefficient of friction. Interpretation of these data suggests a mechanism of sulfur interaction in lubricating systems.

  19. Intensity modulated radiotherapy (IMRT) for pediatric cancer patients: The advantage and fear of second malignant neoplasm

    International Nuclear Information System (INIS)

    Zaghloul, M.S.

    2013-01-01

    Intensity-modulated radiotherapy is used for delivering more efficient homogenous dose to the target and lowering of dose to the surrounding normal tissues. However, a second malignant neoplasm may develop after prolonged latent period. The use of modern precise radiotherapy techniques in the pediatric age group has many controversial issues in spite of its proven dosimetric distribution advantages and the considerable decrease of normal tissue complication probability (NTCP). This concern is due to many factors; mainly the exposure of a larger volume of normal tissues to low dose radiotherapy. Children have more proliferating tissues compared to the adults. However, the epidemiological data did not detect an increase in the incidence of radiation-induced second malignancy. This issue is still controversial as IMRT and other precise radiotherapy techniques were not widely used except recently. This may entail a thorough careful follow up for children treated with these techniques to detect any incidence increase

  20. Comparison of measured and calculated contralateral breast doses in whole breast radiotherapy for VMAT and standard tangent techniques

    International Nuclear Information System (INIS)

    Tse, T.L.J; Bromley, R.; Booth, J.; Gray, A.

    2011-01-01

    Full text: Objective This study aims to evaluate the accuracy of calculated dose with the Eclipse analytical anisotropic algorithm (AAA) for contralateral breast (CB) in left-sided breast radiotherapy for dual-arc VMA T and standard wedged tangent (SWT) techniques. Methods and materials Internal and surface CB doses were measured with EBT2 film in an anthropomorphic phantom mounted with C-cup and D-cup breasts. The measured point dose was approximated by averaging doses over the 4 x 4 mm 2 central region of each 2 x 2 cm2 piece of film. The dose in the target region of the breast was also measured. The measured results were compared to AAA calculations with calculation grids of I, 2.5 and 5 mm. Results In SWT plans, the average ratios of calculation to measurement for internal doses were 0.63 ± 0.081 and 0.5 I ± 0.28 in the medial and lateral aspects, respectively. Corresponding ratios for surface doses were 0.88 ± 0.22 and 0.38 ± 0.38. In VMAT plans, however, the calculation accuracies showed little dependence on the measurement locations, the ratios were 0.78 ± O. I I and 0.81 ± 0.085 for internal and surface doses. In general, finer calculation resolutions did not inevitably improve the dose estimates of internal doses. For surface doses, using smaller grid size I mm could improve the calculation accuracies on the medial but not the lateral aspects of CB. Conclusion In all plans, AAA had a tendency to underestimate both internal and surface CB doses. Overall, it produces more accurate results in VMAT than SWT plans.

  1. Biogeosystem technique - the fundamental base of modern Water Policy and Management

    Science.gov (United States)

    Kalinitchenko, Valery; Batukaev, Abdulmalik; Minkina, Tatiana; Solntseva, Natalia; Skovpen, Andrey; Zarmaev, Ali; Jusupov, Vaha; Lohmanova, Olga

    2014-05-01

    out from active biosphere stage to vadose zone. These substances are entering the undesired stage of sedimentation and lithogenesis. Such adverse events are enhanced by irrigation. As a result, up to 80-90% of the fresh water taken for irrigation from lakes, rivers, storage reservoirs, desalinators are lost useless entailing economic losses. As a result of irrigation the quality of water is deteriorated as well as the quality of soil and landscape. A quality of human environment and a quality of biosphere as a whole is reduced. It is much more dangerous than economic losses. The irrigation paradigm shift is essential for successful water policy and water management in modern world. In a framework of Biogeosystem technics the new intrasoil pulse continuous-discrete paradigm of irrigation is developed. Water is supplied by small discrete portions into individual volumes of a soil continuum without excess soil mass transfer, transpiration, evaporation and seepage. New paradigm of irrigation optimizes plant growth, reduces consumption of water per unit of biological product, the yield increases. It provides the soil and landscape conservation, fresh water - the global deficit - saving up to 10-20 times, biological productivity and sustainability of biosphere. Intrasoil pulse continuous-discrete robotic irrigation technologies match the nowadays noosphere technological platform.

  2. Advances in modern sample preparation techniques using microwaves assisted chemistry for metal species determination (W1)

    International Nuclear Information System (INIS)

    Ponard, O.F.X.

    2002-01-01

    Full text: Sample preparation has long been the bottleneck of environmental analysis for both total and species specific analysis. Digestion, extraction and preparation of the analytes are relying on a series of chemical reactions. The introduction of microwave assisted sample preparation has first been viewed as a mean to accelerate the kinetics of digestion of the matrix for total elements and fast samples preparation procedures. However, the extensive development and success of microwave digestion procedures in total elemental analysis has now allowed to have a larger insight of the perspectives offered by this technique. Microwave technologies now offer to have a precise control of the temperature and indirectly control the reaction kinetics taking place during the sample preparation procedures. Microwave assisted chemistry permits to perform simultaneously the fundamental steps required for metal species extraction and derivatization. The number of sample preparation steps used for organotin or organomercury species have been reduced to one and the total time of sample preparation brought down for a few hours to some minutes. Further, the developments of GC/ICP/MS techniques allow to routinely use speciated isotopic dilution methods has internal probe of the chemical reactions. These new approaches allow us to use the addition of the labeled species for isotopic dilution as a mean to evaluate and follow the chemical processes taking place during the extraction procedure. These procedures will help us to understand and check for the stability of the analytes during the chemistry of the sample preparation procedure and bring some insights of the chemistry taking place during the extraction. Understanding the different mechanisms involved in the sample preparation steps will allow us in return to further improve all theses procedures and bring us to the horizon of 'on-line sample preparation and detection'. (author)

  3. Re-examining TG-142 recommendations in light of modern techniques for linear accelerator based radiosurgery.

    Science.gov (United States)

    Faught, Austin M; Trager, Michael; Yin, Fang-Fang; Kirkpatrick, John; Adamson, Justus

    2016-10-01

    The recent development of multifocal stereotactic radiosurgery (SRS) using a single isocenter volumetric modulated arc theory (VMAT) technique warrants a re-examination of the quality assurance (QA) tolerances for routine mechanical QA recommended by the American Association of Physicists in Medicine Task Group Report Number 142. Multifocal SRS can result in targets with small volumes being at a large off-axis distance from the treatment isocenter. Consequently, angular errors in the collimator, patient support assembly (PSA), or gantry could have an increased impact on target coverage. The authors performed a retrospective analysis of dose deviations caused by systematic errors in PSA, collimator, and gantry angle at the tolerance level for routine linear accelerator QA as recommended by TG-142. Dosimetric deviations from multifocal SRS plans (N = 10) were compared to traditional single target SRS using dynamic conformal arcs (N = 10). The chief dosimetric quantities used in determining clinical impact were V 100% and D 99% of the individual planning target volumes and V 12Gy of the healthy brain. Induced errors at tolerance levels showed the greatest change in multifocal SRS target coverage for collimator rotations (±1.0°) with the average changes to V 100% and D 99% being 5% and 6%, respectively, with maximum changes of 33% and 20%. A reduction in the induced error to half the TG-142 tolerance (±0.5°) demonstrated similar changes in coverage loss to traditional single target SRS assessed at the recommended tolerance level. The observed change in coverage for multifocal SRS was reduced for gantry errors (±1.0°) at 2% and 4.5% for V 100% and D 99% , respectively, with maximum changes of 18% and 12%. Minimal change in coverage was noted for errors in PSA rotation. This study indicates that institutions utilizing a single isocenter VMAT technique for multifocal disease should pay careful attention to the angular mechanical tolerances in designing a robust and

  4. External radiotherapy of pituitary adenomas

    International Nuclear Information System (INIS)

    Zierhut, Dietmar; Flentje, Michael; Adolph, Juergen; Erdmann, Johannes; Raue, Friedhelm; Wannenmacher, Michael

    1995-01-01

    , related to radiotherapy. Both therapeutic effects and side effects occurred after a latency period of 3 months up to 9 years. Conclusion: We conclude that radiotherapy of pituitary adenomas, using modern treatment planning techniques, is effective and safe. To achieve optimal tumor control, doses of 45-48 Gy (conventionally fractionated) should be applied

  5. 20th International Conference for Students and Young Scientists: Modern Techniques and Technologies (MTT'2014)

    International Nuclear Information System (INIS)

    2014-01-01

    The active involvement of young researchers in scientific processes and the acquisition of scientific experience by gifted youth currently have a great value for the development of science. One of the research activities of National Research Tomsk Polytechnic University, aimed at the preparing and formation of the next generation of scientists, is the International Conference of Students and Young Scientists ''Modern Techniques and Technologies'', which was held in 2014 for the twentieth time. Great experience in the organization of scientific events has been acquired through years of carrying the conference. There are all the necessary resources for this: a team of organizers – employees of Tomsk Polytechnic University, premises provided with modern office equipment and equipment for demonstration, and leading scientists – professors of TPU, as well as the status of the university as a leading research university in Russia. This way the conference is able to attract world leading scientists for the collaboration. For the previous years the conference proved itself as a major scientific event at international level, which attracts more than 600 students and young scientists from Russia, CIS and other countries. The conference provides oral plenary and section reports. The conference is organized around lectures, where leading Russian and foreign scientists deliver plenary presentations to young audiences. An important indicator of this scientific event is the magnitude of the coverage of scientific fields: energy, heat and power, instrument making, engineering, systems and devices for medical purposes, electromechanics, material science, computer science and control in technical systems, nanotechnologies and nanomaterials, physical methods in science and technology, control and quality management, design and technology of artistic materials processing. The main issues considered by young researchers at the conference were related to the

  6. Study of Modern Nano Enhanced Techniques for Removal of Dyes and Metals

    Directory of Open Access Journals (Sweden)

    Samavia Batool

    2014-01-01

    Full Text Available Industrial effluent often contains the significant amount of hexavalent chromium and synthetic dyes. The discharge of wastewater without proper treatment into water streams consequently enters the soil and disturbs the aquatic and terrestrial life. A range of wastewater treatment technologies have been proposed which can efficiently reduce both Cr(VI and azo dyes simultaneously to less toxic form such as biodegradation, biosorption, adsorption, bioaccumulation, and nanotechnology. Rate of simultaneous reduction of Cr(VI and azo dyes can be enhanced by combining different treatment techniques. Utilization of synergistic treatment is receiving much attention due to its enhanced efficiency to remove Cr(VI and azo dye simultaneously. This review evaluates the removal methods for simultaneous removal of Cr(VI and azo dyes by nanomicrobiology, surface engineered nanoparticles, and nanophotocatalyst. Sorption mechanism of biochar for heavy metals and organic contaminants is also discussed. Potential microbial strains capable of simultaneous removal of Cr(VI and azo dyes have been summarized in some details as well.

  7. Modern Diagnostic Techniques for the Assessment of Ocular Blood Flow in Myopia: Current State of Knowledge.

    Science.gov (United States)

    Grudzińska, Ewa; Modrzejewska, Monika

    2018-01-01

    Myopia is the most common refractive error and the subject of interest of various studies assessing ocular blood flow. Increasing refractive error and axial elongation of the eye result in the stretching and thinning of the scleral, choroid, and retinal tissues and the decrease in retinal vessel diameter, disturbing ocular blood flow. Local and systemic factors known to change ocular blood flow include glaucoma, medications and fluctuations in intraocular pressure, and metabolic parameters. Techniques and tools assessing ocular blood flow include, among others, laser Doppler flowmetry (LDF), retinal function imager (RFI), laser speckle contrast imaging (LSCI), magnetic resonance imaging (MRI), optical coherence tomography angiography (OCTA), pulsatile ocular blood flowmeter (POBF), fundus pulsation amplitude (FPA), colour Doppler imaging (CDI), and Doppler optical coherence tomography (DOCT). Many researchers consistently reported lower blood flow parameters in myopic eyes regardless of the used diagnostic method. It is unclear whether this is a primary change that causes secondary thinning of ocular tissues or quite the opposite; that is, the mechanical stretching of the eye wall reduces its thickness and causes a secondary lower demand of tissues for oxygen. This paper presents a review of studies assessing ocular blood flow in myopes.

  8. Standardization of Berberis aristata extract through conventional and modern HPTLC techniques

    Directory of Open Access Journals (Sweden)

    Dinesh K. Patel

    2012-05-01

    Full Text Available Objective: Berberis aristata (Berberidaceae is an important medicinal plant, found in the different region of the world. It has significant medicinal value in the traditional Indian and Chinese system of medicine. The aim of the present investigation includes qualitative and quantitative analysis of Berberis aristata extract. Methods: Present study includes determination of phytochemical analysis, solubility test, heavy metal analysis, antimicrobial study and quantitative analysis by HPTLC method. Results: Preliminary phytochemical analysis showed the presence of carbohydrate, glycoside, alkaloid, protein, amino acid, saponin, tannin and flavonoid. Solubility in water and alcohal were found to be 81.90% in water and 84.52% in 50% in alcohal. Loss on drying was found to be 5.32%. Total phenol and flavonoid content were found to be 0.11% and 2.8%. Level of lead, arsenic, mercury and cadmium complies the standard level. E. coli and salmonella was found to be absent whereas total bacterial count, yeast and moulds contents were found to be under the limit. Content of berberine was found to be 13.47% through HPTLC techniques. Conclusions: The results obtained from the present studies could be used as source of valuable information which can play an important role for the food scientists, researchers and even the consumers for its standards.

  9. Using modern imaging techniques to old HST data: a summary of the ALICE program.

    Science.gov (United States)

    Choquet, Elodie; Soummer, Remi; Perrin, Marshall; Pueyo, Laurent; Hagan, James Brendan; Zimmerman, Neil; Debes, John Henry; Schneider, Glenn; Ren, Bin; Milli, Julien; Wolff, Schuyler; Stark, Chris; Mawet, Dimitri; Golimowski, David A.; Hines, Dean C.; Roberge, Aki; Serabyn, Eugene

    2018-01-01

    Direct imaging of extrasolar systems is a powerful technique to study the physical properties of exoplanetary systems and understand their formation and evolution mechanisms. The detection and characterization of these objects are challenged by their high contrast with their host star. Several observing strategies and post-processing algorithms have been developed for ground-based high-contrast imaging instruments, enabling the discovery of directly-imaged and spectrally-characterized exoplanets. The Hubble Space Telescope (HST), pioneer in directly imaging extrasolar systems, has yet been often limited to the detection of bright debris disks systems, with sensitivity limited by the difficulty to implement an optimal PSF subtraction stategy, which is readily offered on ground-based telescopes in pupil tracking mode.The Archival Legacy Investigations of Circumstellar Environments (ALICE) program is a consistent re-analysis of the 10 year old coronagraphic archive of HST's NICMOS infrared imager. Using post-processing methods developed for ground-based observations, we used the whole archive to calibrate PSF temporal variations and improve NICMOS's detection limits. We have now delivered ALICE-reprocessed science products for the whole NICMOS archival data back to the community. These science products, as well as the ALICE pipeline, were used to prototype the JWST coronagraphic data and reduction pipeline. The ALICE program has enabled the detection of 10 faint debris disk systems never imaged before in the near-infrared and several substellar companion candidates, which we are all in the process of characterizing through follow-up observations with both ground-based facilities and HST-STIS coronagraphy. In this publication, we provide a summary of the results of the ALICE program, advertise its science products and discuss the prospects of the program.

  10. Whole brain radiotherapy with adjuvant or concomitant boost in brain metastasis: dosimetric comparison between helical and volumetric IMRT technique.

    Science.gov (United States)

    Borghetti, Paolo; Pedretti, Sara; Spiazzi, Luigi; Avitabile, Rossella; Urpis, Mauro; Foscarini, Federica; Tesini, Giulia; Trevisan, Francesca; Ghirardelli, Paolo; Pandini, Sara Angela; Triggiani, Luca; Magrini, Stefano Maria; Buglione, Michela

    2016-04-19

    To compare and evaluate the possible advantages related to the use of VMAT and helical IMRT and two different modalities of boost delivering, adjuvant stereotactic boost (SRS) or simultaneous integrated boost (SIB), in the treatment of brain metastasis (BM) in RPA classes I-II patients. Ten patients were treated with helical IMRT, 5 of them with SRS after whole brain radiotherapy (WBRT) and 5 with SIB. MRI co-registration with planning CT was mandatory and prescribed doses were 30 Gy in 10 fractions (fr) for WBRT and 15Gy/1fr or 45Gy/10fr in SRS or SIB, respectively. For each patient, 4 "treatment plans" (VMAT SRS and SIB, helical IMRT SRS and SIB) were calculated and accepted if PTV boost was included in 95 % isodose and dose constraints of the main organs at risk were respected without major deviations. Homogeneity Index (HI), Conformal Index (CI) and Conformal Number (CN) were considered to compare the different plans. Moreover, time of treatment delivery was calculated and considered in the analysis. Volume of brain metastasis ranged between 1.43 and 51.01 cc (mean 12.89 ± 6.37 ml) and 3 patients had double lesions. V95% resulted over 95 % in the average for each kind of technique, but the "target coverage" was inadequate for VMAT planning with two sites. The HI resulted close to the ideal value of zero in all cases; VMAT-SIB, VMAT-SRS, Helical IMRT-SIB and Helical IMRT-SRS showed mean CI of 2.15, 2.10, 2.44 and 1.66, respectively (optimal range: 1.5-2.0). Helical IMRT-SRS was related to the best and reliable finding of CN (0.66). The mean of treatment time was 210 s, 467 s, 440 s, 1598 s, respectively, for VMAT-SIB, VMAT-SRS, Helical IMRT-SIB and Helical IMRT-SRS. This dosimetric comparison show that helical IMRT obtain better target coverage and respect of CI and CN; VMAT could be acceptable in solitary metastasis. SIB modality can be considered as a good choice for clinical and logistic compliance; literature's preliminary data are confirming also a

  11. Whole brain radiotherapy with adjuvant or concomitant boost in brain metastasis: dosimetric comparison between helical and volumetric IMRT technique

    International Nuclear Information System (INIS)

    Borghetti, Paolo; Pedretti, Sara; Spiazzi, Luigi; Avitabile, Rossella; Urpis, Mauro; Foscarini, Federica; Tesini, Giulia; Trevisan, Francesca; Ghirardelli, Paolo; Pandini, Sara Angela; Triggiani, Luca; Magrini, Stefano Maria; Buglione, Michela

    2016-01-01

    To compare and evaluate the possible advantages related to the use of VMAT and helical IMRT and two different modalities of boost delivering, adjuvant stereotactic boost (SRS) or simultaneous integrated boost (SIB), in the treatment of brain metastasis (BM) in RPA classes I-II patients. Ten patients were treated with helical IMRT, 5 of them with SRS after whole brain radiotherapy (WBRT) and 5 with SIB. MRI co-registration with planning CT was mandatory and prescribed doses were 30 Gy in 10 fractions (fr) for WBRT and 15Gy/1fr or 45Gy/10fr in SRS or SIB, respectively. For each patient, 4 “treatment plans” (VMAT SRS and SIB, helical IMRT SRS and SIB) were calculated and accepted if PTV boost was included in 95 % isodose and dose constraints of the main organs at risk were respected without major deviations. Homogeneity Index (HI), Conformal Index (CI) and Conformal Number (CN) were considered to compare the different plans. Moreover, time of treatment delivery was calculated and considered in the analysis. Volume of brain metastasis ranged between 1.43 and 51.01 cc (mean 12.89 ± 6.37 ml) and 3 patients had double lesions. V95% resulted over 95 % in the average for each kind of technique, but the “target coverage” was inadequate for VMAT planning with two sites. The HI resulted close to the ideal value of zero in all cases; VMAT-SIB, VMAT-SRS, Helical IMRT-SIB and Helical IMRT-SRS showed mean CI of 2.15, 2.10, 2.44 and 1.66, respectively (optimal range: 1.5–2.0). Helical IMRT-SRS was related to the best and reliable finding of CN (0.66). The mean of treatment time was 210 s, 467 s, 440 s, 1598 s, respectively, for VMAT-SIB, VMAT-SRS, Helical IMRT-SIB and Helical IMRT-SRS. This dosimetric comparison show that helical IMRT obtain better target coverage and respect of CI and CN; VMAT could be acceptable in solitary metastasis. SIB modality can be considered as a good choice for clinical and logistic compliance; literature’s preliminary data are confirming

  12. Labelling techniques of biomolecules for targeted radiotherapy final report of a co-ordinated research project 1998-2002

    CERN Document Server

    International Atomic Energ Agency. Vienna

    2003-01-01

    Malignant tumour disease accounts for approximately one third of deaths worldwide. Gastrointestinal adenocarcinomas, prostate and breast cancers are among the most frequently appearing tumours. Radiotherapy is an essential mode of treatment of all cancer patients either alone or in conjunction with other modalities like surgery and chemotherapy. In most cases radiotherapy is given using external radiation sources. It is also possible to administer radiotherapy by specifically localizing radioisotopes emitting particulate radiation in the tumour tissue. This targeted therapy has proved to have several advantages over external beam therapy, notably the possibility of selectively delivering higher radiation doses to the targeted tumour cells and treating multiple metastases. Procedures for therapy of thyroid carcinoma and hyper-thyroidism using radioiodine (131I) introduced about five decades ago, have stood the test of time and are still widely used the world over. In addition to the therapeutic nuclides of the...

  13. Novel radiotherapy techniques for involved-field and involved-node treatment of mediastinal Hodgkin lymphoma. When should they be considered and which questions remain open

    Energy Technology Data Exchange (ETDEWEB)

    Lohr, Frank; Koeck, Julia; Abo-Madyan, Yasser [University of Heidelberg, Department of Radiation Oncology, University Medical Center Mannheim, Mannheim (Germany); Georg, Dietmar; Knaeusl, Barbara; Dieckmann, Karin [Medical University Vienna/AKH Vienna, Department of Radiation Oncology, Comprehensive Cancer Center, Vienna (Austria); Medical University Vienna/AKH Vienna, Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Comprehensive Cancer Center, Vienna (Austria); Cozzi, Luca [Medical Physics Unit, Oncology Institute of Southern Switzerland, Bellinzona (Switzerland); Eich, Hans Theodor [University Hospital, Department of Radiotherapy, Muenster (Germany); Weber, Damien C. [Paul Scherrer Institute, University of Bern, Center for Proton Therapy, Bern (Switzerland); Fiandra, Christian; Ricardi, Umberto [University of Torino, Radiation Oncology Unit, Department of Oncology, Turin (Italy); Mueller, Rolf-Peter [University of Cologne, Department of Radiation Oncology, Cologne (Germany); Engert, Andreas [University of Cologne, Department of Medical Oncology, Cologne (Germany)

    2014-10-15

    Hodgkin lymphoma (HL) is a highly curable disease. Reducing late complications and second malignancies has become increasingly important. Radiotherapy target paradigms are currently changing and radiotherapy techniques are evolving rapidly. This overview reports to what extent target volume reduction in involved-node (IN) and advanced radiotherapy techniques, such as intensity-modulated radiotherapy (IMRT) and proton therapy-compared with involved-field (IF) and 3D radiotherapy (3D-RT)- can reduce high doses to organs at risk (OAR) and examines the issues that still remain open. Although no comparison of all available techniques on identical patient datasets exists, clear patterns emerge. Advanced dose-calculation algorithms (e.g., convolution-superposition/Monte Carlo) should be used in mediastinal HL. INRT consistently reduces treated volumes when compared with IFRT with the exact amount depending on the INRT definition. The number of patients that might significantly benefit from highly conformal techniques such as IMRT over 3D-RT regarding high-dose exposure to organs at risk (OAR) is smaller with INRT. The impact of larger volumes treated with low doses in advanced techniques is unclear. The type of IMRT used (static/rotational) is of minor importance. All advanced photon techniques result in similar potential benefits and disadvantages, therefore only the degree-of-modulation should be chosen based on individual treatment goals. Treatment in deep inspiration breath hold is being evaluated. Protons theoretically provide both excellent high-dose conformality and reduced integral dose. Further reduction of treated volumes most effectively reduces OAR dose, most likely without disadvantages if the excellent control rates achieved currently are maintained. For both IFRT and INRT, the benefits of advanced radiotherapy techniques depend on the individual patient/target geometry. Their use should therefore be decided case by case with comparative treatment planning

  14. Preliminary analysis of the sequential simultaneous integrated boost technique for intensity-modulated radiotherapy for head and neck cancers.

    Science.gov (United States)

    Miyazaki, Masayoshi; Nishiyama, Kinji; Ueda, Yoshihiro; Ohira, Shingo; Tsujii, Katsutomo; Isono, Masaru; Masaoka, Akira; Teshima, Teruki

    2016-07-01

    The aim of this study was to compare three strategies for intensity-modulated radiotherapy (IMRT) for 20 head-and-neck cancer patients. For simultaneous integrated boost (SIB), doses were 66 and 54 Gy in 30 fractions for PTVboost and PTVelective, respectively. Two-phase IMRT delivered 50 Gy in 25 fractions to PTVelective in the First Plan, and 20 Gy in 10 fractions to PTVboost in the Second Plan. Sequential SIB (SEQ-SIB) delivered 55 Gy and 50 Gy in 25 fractions, respectively, to PTVboost and PTVelective using SIB in the First Plan and 11 Gy in 5 fractions to PTVboost in the Second Plan. Conformity indexes (CIs) (mean ± SD) for PTVboost and PTVelective were 1.09 ± 0.05 and 1.34 ± 0.12 for SIB, 1.39 ± 0.14 and 1.80 ± 0.28 for two-phase IMRT, and 1.14 ± 0.07 and 1.60 ± 0.18 for SEQ-SIB, respectively. CI was significantly highest for two-phase IMRT. Maximum doses (Dmax) to the spinal cord were 42.1 ± 1.5 Gy for SIB, 43.9 ± 1.0 Gy for two-phase IMRT and 40.3 ± 1.8 Gy for SEQ-SIB. Brainstem Dmax were 50.1 ± 2.2 Gy for SIB, 50.5 ± 4.6 Gy for two-phase IMRT and 47.4 ± 3.6 Gy for SEQ-SIB. Spinal cord Dmax for the three techniques was significantly different, and brainstem Dmax was significantly lower for SEQ-SIB. The compromised conformity of two-phase IMRT can result in higher doses to organs at risk (OARs). Lower OAR doses in SEQ-SIB made SEQ-SIB an alternative to SIB, which applies unconventional doses per fraction. © The Author 2016. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  15. Density characterization of radiochromic film through source axis distance (SAD) technique in linac with slab phantom for radiotherapy applications

    Science.gov (United States)

    Hariani, Yousida; Haris, Bambang

    2017-05-01

    Characterization of radiochromic film density is accomplished through Source Axis Distance (SAD) technique in a slab phantom Linac with various depths and breadths of field. Type of the film used is gafchromic RTQA2. The dose of radiation exposure of the film may cause changes in the film density. This research aims to determine the relation between the density and the dose depth through the characteristic of curves to identify the depth of the dose and particular breadth of the field as a reference for the dose of radiotherapy patients. The result shows that the higher the dose is absorbed, the darker the film will be, yet the lower the density is obtained. The dose depth is determined by measuring the amount of dose received at various depths and breadths of field using film that is placed on the slab phantom with 6 MV linac radiation and dose of 300 cGy. The variation of the depth at 1.5 cm; 4 cm; 6 cm; 8 cm; 10 cm, the field size at 4 × 4 cm2, and the dose depth at 359.7 cGy; 315.3 cGy; 281.4 cGy; 241.2 cGy; 220.5 cGy were settled. The field size 6 × 6 cm2 takes the dose depth 354.6 cGy; 314.1 cGy; 282.6 cGy; 244.5 cGy; 224.7 cGy. The field size 8 × 8 cm2 takes the dose depth 351.6 cGy; 313 cGy; 283.8 cGy; 247.2 cGy; 228 cGy. The field size 10 × 10 cm2 takes the dose depth 348.9 cGy; 342.6 cGy; 248.4 cGy; 249.6 cGy; 231 cGy.

  16. Dosimetric comparison of axilla and groin radiotherapy techniques for high-risk and locally advanced skin cancer

    International Nuclear Information System (INIS)

    Mattes, Malcolm D.; Zhou, Ying; Berry, Sean L.; Barker, Christopher A.

    2016-01-01

    Radiation therapy targeting axilla and groin lymph nodes improves regional disease control in locally advanced and high-risk skin cancers. However, trials generally used conventional two-dimensional radiotherapy (2D-RT), contributing towards relatively high rates of side effects from treatment. The goal of this study is to determine if three-dimensional conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), or volumetric-modulated arc therapy (VMAT) may improve radiation delivery to the target while avoiding organs at risk in the clinical context of skin cancer regional nodal irradiation. Twenty patients with locally advanced/high-risk skin cancers underwent computed tomography simulation. The relevant axilla or groin planning target volumes and organs at risk were delineated using standard definitions. Paired t-tests were used to compare the mean values of several dose-volumetric parameters for each of the 4 techniques. In the axilla, the largest improvement for 3D-CRT compared to 2D-RT was for homogeneity index (13.9 vs. 54.3), at the expense of higher lung V 20 (28.0% vs. 12.6%). In the groin, the largest improvements for 3D-CRT compared to 2D-RT were for anorectum D max (13.6 vs. 38.9 Gy), bowel D 200cc (7.3 vs. 23.1 Gy), femur D 50 (34.6 vs. 57.2 Gy), and genitalia D max (37.6 vs. 51.1 Gy). IMRT had further improvements compared to 3D-CRT for humerus D mean (16.9 vs. 22.4 Gy), brachial plexus D 5 (57.4 vs. 61.3 Gy), bladder D 5 (26.8 vs. 36.5 Gy), and femur D 50 (18.7 vs. 34.6 Gy). Fewer differences were observed between IMRT and VMAT. Compared to 2D-RT and 3D-CRT, IMRT and VMAT had dosimetric advantages in the treatment of nodal regions of skin cancer patients

  17. Density characterization of radiochromic film through source axis distance (SAD) technique in linac with slab phantom for radiotherapy applications

    International Nuclear Information System (INIS)

    Hariani, Yousida; Haris, Bambang

    2017-01-01

    Characterization of radiochromic film density is accomplished through Source Axis Distance (SAD) technique in a slab phantom Linac with various depths and breadths of field. Type of the film used is gafchromic RTQA2. The dose of radiation exposure of the film may cause changes in the film density. This research aims to determine the relation between the density and the dose depth through the characteristic of curves to identify the depth of the dose and particular breadth of the field as a reference for the dose of radiotherapy patients. The result shows that the higher the dose is absorbed, the darker the film will be, yet the lower the density is obtained. The dose depth is determined by measuring the amount of dose received at various depths and breadths of field using film that is placed on the slab phantom with 6 MV linac radiation and dose of 300 cGy. The variation of the depth at 1.5 cm; 4 cm; 6 cm; 8 cm; 10 cm, the field size at 4 × 4 cm 2 , and the dose depth at 359.7 cGy; 315.3 cGy; 281.4 cGy; 241.2 cGy; 220.5 cGy were settled. The field size 6 × 6 cm 2 takes the dose depth 354.6 cGy; 314.1 cGy; 282.6 cGy; 244.5 cGy; 224.7 cGy. The field size 8 × 8 cm 2 takes the dose depth 351.6 cGy; 313 cGy; 283.8 cGy; 247.2 cGy; 228 cGy. The field size 10 × 10 cm 2 takes the dose depth 348.9 cGy; 342.6 cGy; 248.4 cGy; 249.6 cGy; 231 cGy. (paper)

  18. Dosimetric comparison of axilla and groin radiotherapy techniques for high-risk and locally advanced skin cancer

    Energy Technology Data Exchange (ETDEWEB)

    Mattes, Malcolm D.; Zhou, Ying; Berry, Sean L.; Barker, Christopher A. [Memorial Sloan Kettering Cancer Center, New York (United States)

    2016-06-15

    Radiation therapy targeting axilla and groin lymph nodes improves regional disease control in locally advanced and high-risk skin cancers. However, trials generally used conventional two-dimensional radiotherapy (2D-RT), contributing towards relatively high rates of side effects from treatment. The goal of this study is to determine if three-dimensional conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), or volumetric-modulated arc therapy (VMAT) may improve radiation delivery to the target while avoiding organs at risk in the clinical context of skin cancer regional nodal irradiation. Twenty patients with locally advanced/high-risk skin cancers underwent computed tomography simulation. The relevant axilla or groin planning target volumes and organs at risk were delineated using standard definitions. Paired t-tests were used to compare the mean values of several dose-volumetric parameters for each of the 4 techniques. In the axilla, the largest improvement for 3D-CRT compared to 2D-RT was for homogeneity index (13.9 vs. 54.3), at the expense of higher lung V{sub 20} (28.0% vs. 12.6%). In the groin, the largest improvements for 3D-CRT compared to 2D-RT were for anorectum D{sub max} (13.6 vs. 38.9 Gy), bowel D{sub 200cc} (7.3 vs. 23.1 Gy), femur D{sub 50} (34.6 vs. 57.2 Gy), and genitalia D{sub max} (37.6 vs. 51.1 Gy). IMRT had further improvements compared to 3D-CRT for humerus D{sub mean} (16.9 vs. 22.4 Gy), brachial plexus D{sub 5} (57.4 vs. 61.3 Gy), bladder D{sub 5} (26.8 vs. 36.5 Gy), and femur D{sub 50} (18.7 vs. 34.6 Gy). Fewer differences were observed between IMRT and VMAT. Compared to 2D-RT and 3D-CRT, IMRT and VMAT had dosimetric advantages in the treatment of nodal regions of skin cancer patients.

  19. Big Data Analytics for Prostate Radiotherapy.

    Science.gov (United States)

    Coates, James; Souhami, Luis; El Naqa, Issam

    2016-01-01

    Radiation therapy is a first-line treatment option for localized prostate cancer and radiation-induced normal tissue damage are often the main limiting factor for modern radiotherapy regimens. Conversely, under-dosing of target volumes in an attempt to spare adjacent healthy tissues limits the likelihood of achieving local, long-term control. Thus, the ability to generate personalized data-driven risk profiles for radiotherapy outcomes would provide valuable prognostic information to help guide both clinicians and patients alike. Big data applied to radiation oncology promises to deliver better understanding of outcomes by harvesting and integrating heterogeneous data types, including patient-specific clinical parameters, treatment-related dose-volume metrics, and biological risk factors. When taken together, such variables make up the basis for a multi-dimensional space (the "RadoncSpace") in which the presented modeling techniques search in order to identify significant predictors. Herein, we review outcome modeling and big data-mining techniques for both tumor control and radiotherapy-induced normal tissue effects. We apply many of the presented modeling approaches onto a cohort of hypofractionated prostate cancer patients taking into account different data types and a large heterogeneous mix of physical and biological parameters. Cross-validation techniques are also reviewed for the refinement of the proposed framework architecture and checking individual model performance. We conclude by considering advanced modeling techniques that borrow concepts from big data analytics, such as machine learning and artificial intelligence, before discussing the potential future impact of systems radiobiology approaches.

  20. Transition from 2-D radiotherapy to 3-D conformal and intensity modulated radiotherapy

    International Nuclear Information System (INIS)

    2008-05-01

    Cancer is one of the leading causes of death globally and radiotherapy is currently an essential component in the management of cancer patients, either alone or in combination with surgery or chemotherapy, both for cure or palliation. It is now recognized that safe and effective radiotherapy service needs not only substantial capital investment in radiotherapy equipment and specially designed facilities but also continuous investment in maintenance and upgrading of the equipment to comply with the technical progress, but also in training the staff. The recent IAEA-TECDOC publication 'Setting up a Radiotherapy Programme: Clinical, Medical Physics, Radiation Protection and Safety Aspects' provides general guidelines for designing and implementing radiotherapy services in Member States. Advances in computer technology have enabled the possibility of transitioning from basic 2- dimensional treatment planning and delivery (2-D radiotherapy) to a more sophisticated approach with 3-dimensional conformal radiotherapy (3-D CRT). Whereas 2-D radiotherapy can be applied with simple equipment, infrastructure and training, transfer to 3-D conformal treatments requires more resources in technology, equipment, staff and training. A novel radiation treatment approach using Intensity Modulated Radiation Therapy (IMRT) that optimizes the delivery of radiation to irregularly shaped tumour volumes demands even more sophisticated equipment and seamless teamwork, and consequentially more resources, advanced training and more time for treatment planning and verification of dose delivery than 3-D CRT. Whereas 3-D CRT can be considered as a standard, IMRT is still evolving. Due to the increased interest of Member States to the modern application of radiotherapy the IAEA has received a number of requests for guidance coming from radiotherapy departments that wish to upgrade their facilities to 3-D CRT and IMRT through Technical Cooperation programme. These requests are expected to increase

  1. An easy irradiation technique (partial half-beam) to reduce renal dose in radiotherapy of cervical cancer including paraaortic lymph nodes

    International Nuclear Information System (INIS)

    Vorwerk, H.; Wagner, D.; Christiansen, H.; Hess, C.F.; Hermann, R.M.

    2008-01-01

    Purpose: for radiation treatment of patients with cervical cancer and a high risk for paraaortic lymph node involvement, an easy three-dimensional (3-D) conformal irradiation technique (partial half-beam [PHB]) for protection of organs at risk, especially of renal tissue, was developed. Patients and methods: in five consecutive female patients a computed tomography scan was performed. Dose-volume histograms of the renal tissue and other organs at risk were analyzed for PHB, three other 3-D conformal techniques, and an intensity-modulated radiotherapy (IMRT) technique. Results: the PHB technique reduced the renal volume and volumes of other organs at risk exposed to radiation doses when comparing all patients to the other 3-D conformal techniques. With use of the IMRT technique more renal tissue volume received very low radiation doses (≤ 6.8 Gy) whereas the D 10 was lower than with the PHB technique. Conclusion: in female patients with cervical cancer and high risk for paraaortic lymph node involvement, the use of the PHB technique is recommended to reduce renal radiation exposure, if no IMRT technique should be applied. The PHB technique is very easily and fast applicable. (orig.)

  2. Commissioning of radiotherapy treatment planning systems: Testing for typical external beam treatment techniques. Report of the Coordinated Research Project (CRP) on Development of Procedures for Quality Assurance of Dosimetry Calculations in Radiotherapy

    International Nuclear Information System (INIS)

    2008-01-01

    Quality Assurance (QA) in the radiation therapy treatment planning process is essential to ensure accurate dose delivery to the patient and to minimize the possibility of accidental exposure. Computerized radiotherapy treatment planning systems (RTPSs) are now widely available in both industrialised and developing countries so, it is of special importance to support hospitals in the IAEA Member States in developing procedures for acceptance testing, commissioning and ongoing QA of their RTPSs. Responding to these needs, a group of experts developed a comprehensive report, the IAEA Technical Reports Series No 430 'Commissioning and quality assurance of computerized planning systems for radiation treatment of cancer', that provides the general framework and describes a large number of tests and procedures to be considered by the RTPS users. To provide practical guidance for implementation of IAEA Technical Reports Series No. 430 in radiotherapy hospitals and particularly in those with limited resources, a coordinated research project (CRP E2.40.13) 'Development of procedures for dosimetry calculation in radiotherapy' was established. The main goal of the project was to create a set of practical acceptance and commissioning tests for dosimetry calculations in radiotherapy, defined in a dedicated protocol. Two specific guidance publications that were developed in the framework of the Coordinated Research Project E2.40.13 are based on guidelines described in the IAEA Technical Report Series No. 430 and provide a step-by-step description for users at hospitals or cancer centres how to implement acceptance and commissioning procedures for their RTPSs. The first publication, 'Specification and acceptance testing of radiotherapy treatment planning systems' IAEA-TECDOC-1540 uses the International Electrotechnical Commission (IEC) standard IEC 62083 as its basis and addresses the procedures for specification and acceptance testing of RTPSs to be used by both manufacturers and

  3. Radiotherapy equipment for conformal radiotherapy and IMRT in the Czech Republic

    International Nuclear Information System (INIS)

    Horakova, I.; Irena Pavlikova, I.; Novotny, J. ml.

    2005-01-01

    The development of the equipment of radiotherapy departments in the Czech Republic is presented here. The data from the special questionnaire from 14 workplaces with linear accelerators with multi-leaf collimators (MLC) and electronic portal imaging device (EPID) are included. They show not only the equipment specification but also the application methods, the quality control, plans for future etc. In the Czech Republic, a great extension of modem irradiation techniques and accessories occurs at present. Together with it, it is necessary to develop quality assurance of the whole process of dose delivery to the patient. It is also necessary to assure further education and training of hospital staff. Modern radiotherapy techniques demand sufficient amount of all sources including personal sources. (authors)

  4. Design of a technique for the radiotherapy treatment of patients of prostate with bilateral prosthetic hip; Diseno de una tecnica para el tratamiento radioterapico de pacientes de prostata con protesis bilateral de cadera

    Energy Technology Data Exchange (ETDEWEB)

    Camacho, C.; Perez-Alija, J.; Olivares, S.; Loscos, S.; Pedro, A.

    2013-07-01

    The design of the plan of treatment of patients who have to undergo radical radiotherapy of prostate and that incorporate some sort of hip prosthesis is usually complex. the case of a patient's prostatic bed with bilateral hip prosthesis to assess radical radiotherapy to the 70Gy in bed. The objective of this paper is to present the chosen technique designed for this treatment. (Author)

  5. Postmastectomy radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Shikama, Naoto; Koguchi, Masahiko; Sasaki, Shigeru; Kaneko, Tomoki; Shinoda, Atsunori; Nishikawa, Atsushi [Shinshu Univ., Matsumoto, Nagano (Japan). School of Medicine

    2000-10-01

    Since there have been few reports on postmastectomy radiotherapy having a high evidence level in Japan, the significance of postoperative radiotherapy and the irradiation techniques were reviewed based on reports from Western countries. Authors focused on the indications for postoperative irradiation, irradiation methods (irradiation sites, irradiation techniques; prosthetics, methods of irradiating the chest wall and lymph nodes, timing of irradiation), and complications, and discuss them. The factors thought to be adaptable to postmastectomy radiotherapy have been listed. Axillary lymph node metastasis and the size of the primary focus are thought to be important factors in locoregional recurrence. The chest wall and the supraclavicular lymph nodes are the usual sites of irradiation after mastectomy. The irradiation method consists of tangential irradiation of the chest wall and single-field irradiation of the supraclavicular lymph nodes, with 46-50 Gy in fractional doses of 1.8-2 Gy x 5/w is administered for 4.5-5.5 weeks. The timing of irradiation in the West is generally after chemotherapy. Adverse radiation effects include ischemic heart disease, pneumonitis, arm edema, rib fractures, and brachial plexus paralysis. The frequency of these complications is increased by the combined use of chemotherapy or surgery. The breast cancer cure rate in Japan is generally better than in the West. It remains to be determined whether the clinical data from Europe and America are applicable to the treatment of breast cancer in Japan. To address this issue, a clinical investigation should be performed in Japan with close cooperation between surgeons, physicians, pathologists, and radiotherapists. (K.H.)

  6. To understand radiotherapy

    International Nuclear Information System (INIS)

    2009-01-01

    Dealing with the use of radiotherapy for adults, this guide indicates when a radiotherapy is suggested, how it acts, how the treatment is chosen, which are the professionals involved. It describes how an external radiotherapy takes place and its various techniques, the different types of side effects (general, specific to the treated zone, late effects). It indicates which organs can be treated by curie-therapy, the different curie-therapy treatment modalities, how a curie-therapy takes place and which are its side effects. It outlines how to better cope with radiotherapy (how to be supported, the important role of relatives, everyday life questions, rights). It indicates and comments the different measures adopted for the safety and quality of radiotherapy

  7. Characterization of pre-hispanic pigments by modern analytical techniques; Caracterizacion de pigmentos prehispanicos por tecnicas analiticas modernas

    Energy Technology Data Exchange (ETDEWEB)

    Ortega A, M

    2003-07-01

    In this work, the study of mural painting pigments from two archaeological sites (The Great Temple in Mexico city and Cacaxtla) was performed to know their materials composition, identify their structural characteristics and properties by using modern analytical techniques. Blue, ochre, red and black pigments of Mexica culture (1325-1521 a.C. / late Post Classic period); blue, ochre, red, brown, pink, green and white of Olmeca- Xicalanca culture (700-900 a.C. / Epiclassic period) were studied. Data about materials used, technological evolution, mineralogical background, cultural interchange and origin was obtained. Environmental exposition of these paintings since their discovering has produced changes and damage on their materials. Therefore, stability of some pigments has been notorious, ''Maya Blue'' specially presents extraordinary resistance to diluted and concentrated acids and alkalis including boiling condition, acqua regia, solvents, oxidant and reducing agents, moderate heat and biocorrosi6n; for that reason its study was emphasized. ''Maya Blue'' pigment was synthesized in laboratory using the processes described by historic sources (with indigophera suffruticosa leaves and synthetic indigo) up to obtain a stable pigment including acqua regia action. Clay matrix sorbs nearly 0.4 weight percent of organic dye, which cover 79% of palygorskita surface area. (Author)

  8. Characterization of pre-hispanic pigments by modern analytical techniques; Caracterizacion de pigmentos prehispanicos por tecnicas analiticas modernas

    Energy Technology Data Exchange (ETDEWEB)

    Ortega A, M

    2003-07-01

    In this work, the study of mural painting pigments from two archaeological sites (The Great Temple in Mexico city and Cacaxtla) was performed to know their materials composition, identify their structural characteristics and properties by using modern analytical techniques. Blue, ochre, red and black pigments of Mexica culture (1325-1521 a.C. / late Post Classic period); blue, ochre, red, brown, pink, green and white of Olmeca- Xicalanca culture (700-900 a.C. / Epiclassic period) were studied. Data about materials used, technological evolution, mineralogical background, cultural interchange and origin was obtained. Environmental exposition of these paintings since their discovering has produced changes and damage on their materials. Therefore, stability of some pigments has been notorious, ''Maya Blue'' specially presents extraordinary resistance to diluted and concentrated acids and alkalis including boiling condition, acqua regia, solvents, oxidant and reducing agents, moderate heat and biocorrosi6n; for that reason its study was emphasized. ''Maya Blue'' pigment was synthesized in laboratory using the processes described by historic sources (with indigophera suffruticosa leaves and synthetic indigo) up to obtain a stable pigment including acqua regia action. Clay matrix sorbs nearly 0.4 weight percent of organic dye, which cover 79% of palygorskita surface area. (Author)

  9. Total Skin Electron Therapy for Cutaneous T-Cell Lymphoma Using a Modern Dual-Field Rotational Technique

    Energy Technology Data Exchange (ETDEWEB)

    Heumann, Thatcher R. [Emory University School of Medicine, Emory University, Atlanta, Georgia (United States); Esiashvili, Natia [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute (WCI), Emory University, Atlanta, Georgia (United States); Parker, Sareeta [Department of Dermatology, Emory University, Atlanta, Georgia (United States); Switchenko, Jeffrey M. [Biostatistics Shared Core Resource at WCI, Emory University, Atlanta, Georgia (United States); Dhabbaan, Anees [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute (WCI), Emory University, Atlanta, Georgia (United States); Goodman, Michael [Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia (United States); Lechowicz, Mary Jo; Flowers, Christopher R. [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Department of Hematology and Oncology, Emory University, Atlanta, Georgia (United States); Khan, Mohammad K., E-mail: drkhurram2000@gmail.com [Department of Radiation Oncology, Emory University, Atlanta, Georgia (United States); Winship Cancer Institute (WCI), Emory University, Atlanta, Georgia (United States)

    2015-05-01

    Purpose: To report our experience with rotational total skin electron irradiation (RTSEI) in cutaneous T-cell lymphoma (CTCL), and to examine response by disease stage and race. Methods and Materials: We reviewed our outcomes for 68 CTCL patients who received RTSEI (≥30 Gy) from 2000 to 2013. Primary outcomes were complete clinical response (CCR), recurrence-free survival (RFS), and overall survival (OS). Using log–rank tests and Cox proportional hazards, OS and RFS were compared across tumor stages at time of RTSEI with further racial subgroup analysis. Results: Median age at diagnosis and at time of radiation was 52 and 56 years, respectively. Median follow-up was 5.1 years, 49% were African American, and 49% were female. At time of treatment, 18, 37, and 13 patients were T stage 2, 3, and 4, respectively. At 6 weeks after RTSEI, overall CCR was 82% (88%, 83%, and 69% for T2, T3, and T4, respectively). Median RFS was 11 months for all patients and 14, 10, and 12 months for stage T2, T3, and T4, respectively. Tumor stage was not associated with RFS or CCR. Maintenance therapy after RTSEI was associated with improved RFS in both crude and multivariable analysis, controlling for T stage. Median OS was 76 months (91 and 59 months for T3 and T4, respectively). With the exception of improved OS in African Americans compared with whites at stage T2, race was not associated with CCR, RFS, or OS. Conclusions: These results represent the largest RTSEI clinical outcomes study in the modern era using a dual-field rotational technique. Our observed response rates match or improve upon the standard set by previous outcome studies using conventional TSEI techniques, despite a large percentage of advanced CTCL lesions in our cohort. We found that clinical response after RTSEI did not seem to be affected by T stage or race.

  10. Nasopharyngeal Carcinoma Treated with Precision-Oriented Radiation Therapy Techniques Including Intensity-Modulated Radiotherapy: Preliminary Results

    Directory of Open Access Journals (Sweden)

    Wen-Shan Liu

    2004-02-01

    Full Text Available This paper reports preliminary results with intensity-modulated radiotherapy (IMRT in nasopharyngeal carcinoma (NPC. Between August 2000 and May 2001, we treated 19 patients with NPC using IMRT. Twelve patients had stage I-II disease and seven had stage III-IV disease. Six patients received 9.0-19.8 Gy three-dimensional conformal radiotherapy (3D-CRT before IMRT and 18 patients received a brachytherapy boost after IMRT. The mean follow-up time was 13.0 months. All patients with stage II-IV disease except one received two cycles of chemoradiotherapy with cisplatin and 5-fluorouracil (5-FU during radiotherapy, followed by two to four cycles of chemotherapy after radiotherapy. Tumor response was assessed using clinical examination and computerized tomography or magnetic resonance imaging. The mean doses administered to the gross tumor volume and clinical tumor volume were 70.9 Gy and 63.2 Gy, respectively. The mean doses administered to the right and left parotid glands were 38.1 Gy and 38.6 Gy, respectively. All 19 patients had a complete response of primary and lymph node disease. Grade III mucositis developed during chemoradiotherapy in 15 patients (79%. In addition, clinical grade I xerostomia was recorded in nine patients, grade II in nine, and grade III in one. This study demonstrated that 3D-CRT, IMRT, intracavitary brachytherapy, and chemotherapy are effective and safe methods to treat NPC. Although IMRT treatment spared parotid gland function, its efficacy may be significantly influenced by disease stage and location of the neck lymph nodes. More cases and a longer follow-up to assess survival and complications are planned.

  11. Contact radiotherapy. Report of technological assessment

    International Nuclear Information System (INIS)

    Ortholan, Cecile; Melin, Nicole; Lee-Robin, Sun Hae; David, Denis Jean; Pages, Frederique; Devaud, Christine; Noel, Georges; Biga, Julie; Moty-Monnereau, Celine; Canet, Philippe; Lascols, Sylvie; Lamas, Muriel; Ramdine, Jessica; Tuil, Louise

    2008-10-01

    This report aims at assessing safety, indications, the role in therapeutic strategy, and efficiency of contact radiotherapy. It also aims at answering questions like: is the contact radiotherapy technique validated? What are the indications for contact radiotherapy? What about the efficiency and safety of contact radiotherapy? After a presentation of preliminary notions on radiotherapy (radiation types, dose, and irradiation techniques), the report presents this specific technique of contact radiotherapy: definition, devices, use recommendations, issues of radiation protection, modalities of performance of a contact radiotherapy session, and concerned pathologies. Then, based on a literature survey, this report addresses the various concerned tumours (skin, rectum, brain, breast), indicates some general information about these tumours (epidemiological data, anatomy and classification, therapeutic options, radiotherapy), and proposes an assessment of the efficiency and safety of contact radiotherapy

  12. Optimisation of radiotherapy for carcinoma of the parotid gland: a comparison of conventional, three-dimensional conformal, and intensity-modulated techniques

    International Nuclear Information System (INIS)

    Nutting, Christopher M.; Rowbottom, Carl G.; Cosgrove, Vivian P.; Henk, J. Michael; Dearnaley, David P.; Robinson, Martin H.; Conway, John; Webb, Steve

    2001-01-01

    Background and purpose: To compare external beam radiotherapy techniques for parotid gland tumours using conventional radiotherapy (RT), three-dimensional conformal radiotherapy (3DCRT), and intensity-modulated radiotherapy (IMRT). To optimise the IMRT techniques, and to produce an IMRT class solution. Materials and methods: The planning target volume (PTV), contra-lateral parotid gland, oral cavity, brain-stem, brain and cochlea were outlined on CT planning scans of six patients with parotid gland tumours. Optimised conventional RT and 3DCRT plans were created and compared with inverse-planned IMRT dose distributions using dose-volume histograms. The aim was to reduce the radiation dose to organs at risk and improve the PTV dose distribution. A beam-direction optimisation algorithm was used to improve the dose distribution of the IMRT plans, and a class solution for parotid gland IMRT was investigated. Results: 3DCRT plans produced an equivalent PTV irradiation and reduced the dose to the cochlea, oral cavity, brain, and other normal tissues compared with conventional RT. IMRT further reduced the radiation dose to the cochlea and oral cavity compared with 3DCRT. For nine- and seven-field IMRT techniques, there was an increase in low-dose radiation to non-target tissue and the contra-lateral parotid gland. IMRT plans produced using three to five optimised intensity-modulated beam directions maintained the advantages of the more complex IMRT plans, and reduced the contra-lateral parotid gland dose to acceptable levels. Three- and four-field non-coplanar beam arrangements increased the volume of brain irradiated, and increased PTV dose inhomogeneity. A four-field class solution consisting of paired ipsilateral coplanar anterior and posterior oblique beams (15, 45, 145 and 170 degree sign from the anterior plane) was developed which maintained the benefits without the complexity of individual patient optimisation. Conclusions: For patients with parotid gland tumours

  13. State-of-the-art treatment alternatives for base of skull meningiomas: complementing and controversial indications for neurosurgery, stereotactic and robotic based radiosurgery or modern fractionated radiation techniques

    International Nuclear Information System (INIS)

    Combs, Stephanie E; Ganswindt, Ute; Foote, Robert L; Kondziolka, Douglas; Tonn, Jörg-Christian

    2012-01-01

    For skull base meningiomas, several treatment paradigms are available: Observation with serial imaging, surgical resection, stereotactic radiosurgery, radiation therapy or some combination of both. The choice depends on several factors. In this review we evaluate different treatment options, the outcome of modern irradiation techniques as well as the clinical results available, and establish recommendations for the treatment of patients with skull-base meningiomas

  14. An investigation into the application of modern heuristic optimisation techniques to problems in power and processing utilities

    International Nuclear Information System (INIS)

    Dahal, Keshav Prasad

    2000-01-01

    The work contained in this thesis demonstrates that there is a significant requirement for the development and application of new optimisation techniques for solving industrial scheduling problems, in order to achieve a better schedule with significant economic and operational impact. An investigation of how modern heuristic approaches, such as genetic algorithm (GA), simulated annealing (SA), fuzzy logic and hybrids of these techniques, may be developed, designed and implemented appropriately for solving short term and long term NP-hard scheduling problems that exist in electric power utilities and process facilities. GA and SA based methods are developed for generator maintenance scheduling using a novel integer encoding and appropriate GA and SA operators. Three hybrid approaches (an inoculated GA, a GA/SA and a GA with fuzzy logic) are proposed in order to improve the solution performance, and to take advantage of any flexibilities inherent in the problem. Five different GA-based approaches are investigated for solving the generation scheduling problem. Of those, a knowledge-based hybrid GA approach achieves better solutions in a shorter computational time. This approach integrates problem specific knowledge, heuristic dispatch calculation and linear programming within the GA-framework. The application of a GA-based methodology is proposed for the scheduling of storage tanks of a water treatment facility. The proposed approach is an integration of a GA and a heuristic rule-base. The GA string considers the tank allocation problem, and the heuristic approach solves the rate determination problems within the framework of the GA. For optimising the schedule of operations of a bulk handling port facility, a generic modelling tool is developed characterising the operational and maintenance activities of the facility. A GA-based approach is integrated with the simulation software for optimising the scheduling of operations of the facility. Each of these approaches is

  15. Historical review of radiotherapy

    International Nuclear Information System (INIS)

    Onai, Yoshio

    1993-01-01

    The techniques of radiotherapy have been improved by development of particle accelerators, radionuclides and computers. This paper presents a historical review of the physical and technical aspects of radiotherapy in Japan. Changes in the kinds of radiation, such as X-rays, gamma rays, electrons, neutrons and protons used for external radiotherapy, and the equipment involved are described chronologically, and historical changes in the quality of radiotherapy apparatus are outlined. Patient data acquisition equipment, such as X-ray simulator and X-ray CT, beam modifying devices, patient setup devices, and devices to verify treatment fields and patient doses are reviewed historically. Radiation sources for brachytherapy and internal radiotherapy, and remotely controlled afterloading systems are reviewed chronologically. Historical changes in methods to evaluate absorbed doses, dose monitor systems and beam data acquisition systems are outlined. Changes in methods of calculating dose distributions for external X-ray and electron therapy, brachytherapy and internal radiotherapy by unsealded radionuclides are described and calculation techniques for treatment planning system are reviewed. Annual figures in the numbers of radiotherapy equipment, such as telecobalt and telecesium units, linear accelerators, betatrons, microtrons, stereotactic gamma units, conformation radiotherapy units, remotely controlled afterloading systems, and associated equipment such as X-ray simulators and treatment planning systems are provided, as are changes in the number of accelerators by maximum X-ray energy and maximum electron energy, and in the number of licensed hospitals and clinics using small sealed sources. Changes in techniques of external radiotherapy and brachytherapy are described briefly from the point of view of dose distributions. (author)

  16. The UK HeartSpare Study (Stage IB): Randomised comparison of a voluntary breath-hold technique and prone radiotherapy after breast conserving surgery

    International Nuclear Information System (INIS)

    Bartlett, Frederick R.; Colgan, Ruth M.; Donovan, Ellen M.; McNair, Helen A.; Carr, Karen; Evans, Philip M.; Griffin, Clare; Locke, Imogen; Haviland, Joanne S.; Yarnold, John R.; Kirby, Anna M.

    2015-01-01

    Purpose: To compare mean heart and left anterior descending coronary artery (LAD) doses (NTD mean ) and positional reproducibility in larger-breasted women receiving left breast radiotherapy using supine voluntary deep-inspiratory breath-hold (VBH) and free-breathing prone techniques. Materials and methods: Following surgery for early breast cancer, patients with estimated breast volumes >750 cm 3 underwent planning-CT scans in supine VBH and free-breathing prone positions. Radiotherapy treatment plans were prepared, and mean heart and LAD doses were calculated. Patients were randomised to receive one technique for fractions 1–7, before switching techniques for fractions 8–15 (40 Gy/15 fractions total). Daily electronic portal imaging and alternate-day cone-beam CT (CBCT) imaging were performed. The primary endpoint was the difference in mean LAD NTD mean between techniques. Population systematic (Σ) and random errors (σ) were estimated. Within-patient comparisons between techniques used Wilcoxon signed-rank tests. Results: 34 patients were recruited, with complete dosimetric data available for 28. Mean heart and LAD NTD mean doses for VBH and prone treatments respectively were 0.4 and 0.7 (p < 0.001) and 2.9 and 7.8 (p < 0.001). Clip-based CBCT errors for VBH and prone respectively were ⩽3.0 mm and ⩽6.5 mm (Σ) and ⩽3.5 mm and ⩽5.4 mm (σ). Conclusions: In larger-breasted women, supine VBH provided superior cardiac sparing and reproducibility than a free-breathing prone position

  17. Second malignancy in young early-stage breast cancer patients with modern radiotherapy: A long-term population-based study (A STROBE-compliant study).

    Science.gov (United States)

    Xie, Liyi; Lin, Chen; Zhang, Huan; Bao, Xuhui

    2018-04-01

    Second cancer is a leading cause of death in long-term survivors of younger early-stage breast cancer patients. To date, relationship of age, receipt of radiotherapy (RT), and estimated doses received by target organs have not yet been well elucidated. Using Surveillance, Epidemiology, and End Results database, patients aged 20 to 44, diagnosed with a first primary staging I-IIIA ipsilateral breast invasive ductal carcinoma, underwent surgery during 1988 to 2009 were identified, and those with a second malignancy at ≥1-year follow-up were analyzed to calculate cumulative incidences (CIs) of second malignancy in whole group and each subgroup. Subgroups were dichotomized by surgery type, axillary dissection, and axillary lymph node status. With a median follow-up of 11.8 years, 22,628 women including 1495 patients (6.6%) developing second malignancies (3.7% contralateral breast cancer, 2.9% non-breast second malignancies, and 0.7% high-dose site second malignancies) were identified. Three-dimensional coordinate systems with age at primary diagnosis, time after primary breast cancer diagnosis, and CI of second malignancy as 3 axes, for endpoints including all second malignancy, second primary contralateral breast cancer, and non-breast second malignancy were presented, along with the risk in RT and non-RT groups in overall group and subgroups. Five-, 10-, 15-, and 20-year all second malignancy-free survivals in RT and non-RT groups were 89.5% versus 85.4%, 80.1% versus 75.0%, 72.9% versus 67.9%, and 65.6% versus 61.8% (P < .0001). From the large national dataset, a broad visualized overview of second malignancy risk, including second contralateral breast cancer and non-breast second cancer, suggests generally beneficial therapeutic ratio for radiotherapy in young women with early-stage breast cancer.

  18. Biogeosystem technique as a method to overcome the Biological and Environmental Hazards of modern Agricultural, Irrigational and Technological Activities

    Science.gov (United States)

    Kalinitchenko, Valery; Batukaev, Abdulmalik; Zinchenko, Vladimir; Zarmaev, Ali; Magomadov, Ali; Chernenko, Vladimir; Startsev, Viktor; Bakoev, Serojdin; Dikaev, Zaurbek

    2014-05-01

    Modern challenge for humanity is to replace the paradigm of nature use and overcome environmental hazards of agronomy, irrigation, industry, and other human activities in biosphere. It is utterly reasonable to stop dividing biosphere on shares - the human habitat and the environment. In the 21st century it is an outdated anthropocentrism. Contradicting himself to biosphere Humankind has the problems. The new paradigm of biosphere control by methods of Biogeosystem technique is on agenda of Humankind. Key directions of Biogeosystem technique. Tillage. Single rotary milling 20…30-50…60 sm soil layer optimizes the evolution and environment of soil, creates a favorable conditions for the rhizosphere, increases the biological productivity of biosphere by 30-50% compared to the standard agricultural practices for the period up to 40 years. Recycle material. Recycling of mineral and organic substances in soil layer of 20…30-50…60 sm in rotary milling soil processing provides wastes clean return to biosphere. Direct intrasoil substances synthesis. Environmentally friendly robot wasteless nanotechnology provides direct substances synthesis, including fertilizers, inside the soil. It eliminates the prerequisites of the wastes formation under standard industrial technologies. Selective substance's extraction from soil. Electrochemical robotic nanotechnology provides selective substances extraction from soil. The technology provides recovery, collection and subsequent safe industrial use of extracted substances out of landscape. Saving fresh water. An important task is to save fresh water in biosphere. Irrigation spends water 4-5 times more of biological requirements of plants, leads to degradation of soil and landscape. The intrasoil pulse continuous-discrete paradigm of irrigation is proposed. It provides the soil and landscape conservation, increases the biological productivity, save the fresh water up to 10-20 times. The subsurface soil rotary processing and

  19. Effective porosity and density of carbonate rocks (Maynardville Limestone and Copper Ridge Dolomite) within Bear Creek Valley on the Oak Ridge Reservation based on modern petrophysical techniques

    International Nuclear Information System (INIS)

    Dorsch, J.

    1997-02-01

    The purpose of this study is to provide quantitative data on effective porosity of carbonate rock from the Maynardville Limestone and Copper Ridge Dolomite within Bear Creek Valley based on modern petrophysical techniques. The data will be useful for groundwater-flow and contaminant-flow modeling in the vicinity of the Y-12 Plant on the Oak Ridge Reservation (ORR). Furthermore, the data provides needed information on the amount of interconnected pore space potentially available for operation of matrix diffusion as a transport process within the fractured carbonate rock. A second aspect of this study is to compare effective porosity data based on modern petrophysical techniques to effective porosity data determined earlier by Goldstrand et al. (1995) with a different technique. An added bonus of the study is quantitative data on the bulk density and grain density of dolostone and limestone of the Maynardville Limestone and Copper Ridge Dolomite which might find use for geophysical modeling on the ORR

  20. Who Should Bear the Cost of Convenience? A Cost-effectiveness Analysis Comparing External Beam and Brachytherapy Radiotherapy Techniques for Early Stage Breast Cancer.

    Science.gov (United States)

    McGuffin, M; Merino, T; Keller, B; Pignol, J-P

    2017-03-01

    Standard treatment for early breast cancer includes whole breast irradiation (WBI) after breast-conserving surgery. Recently, accelerated partial breast irradiation (APBI) has been proposed for well-selected patients. A cost and cost-effectiveness analysis was carried out comparing WBI with two APBI techniques. An activity-based costing method was used to determine the treatment cost from a societal perspective of WBI, high dose rate brachytherapy (HDR) and permanent breast seed implants (PBSI). A Markov model comparing the three techniques was developed with downstream costs, utilities and probabilities adapted from the literature. Sensitivity analyses were carried out for a wide range of variables, including treatment costs, patient costs, utilities and probability of developing recurrences. Overall, HDR was the most expensive ($14 400), followed by PBSI ($8700), with WBI proving the least expensive ($6200). The least costly method to the health care system was WBI, whereas PBSI and HDR were less costly for the patient. Under cost-effectiveness analyses, downstream costs added about $10 000 to the total societal cost of the treatment. As the outcomes are very similar between techniques, WBI dominated under cost-effectiveness analyses. WBI was found to be the most cost-effective radiotherapy technique for early breast cancer. However, both APBI techniques were less costly to the patient. Although innovation may increase costs for the health care system it can provide cost savings for the patient in addition to convenience. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  1. Impact of inter- and intrafraction deviations and residual set-up errors on PTV margins. Different alignment techniques in 3D conformal prostate cancer radiotherapy

    International Nuclear Information System (INIS)

    Langsenlehner, T.; Doeller, C.; Winkler, P.; Kapp, K.S.; Galle, G.

    2013-01-01

    The aim of this work was to analyze interfraction and intrafraction deviations and residual set-up errors (RSE) after online repositioning to determine PTV margins for 3 different alignment techniques in prostate cancer radiotherapy. The present prospective study included 44 prostate cancer patients with implanted fiducials treated with three-dimensional (3D) conformal radiotherapy. Daily localization was based on skin marks followed by marker detection using kilovoltage (kV) imaging and subsequent patient repositioning. Additionally, in-treatment megavoltage (MV) images were obtained for each treatment field. In an off-line analysis of 7,273 images, interfraction prostate motion, RSE after marker-based prostate localization, prostate position during each treatment session, and the effect of treatment time on intrafraction deviations were analyzed to evaluate PTV margins. Margins accounting for interfraction deviation, RSE and intrafraction motion were 14.1, 12.9, and 15.1 mm in anterior-posterior (AP), superior-inferior (SI), and left-right (LR) direction for skin mark alignment and 9.6, 8.7, and 2.6 mm for bony structure alignment, respectively. Alignment to implanted markers required margins of 4.6, 2.8, and 2.5 mm. As margins to account for intrafraction motion increased with treatment prolongation PTV margins could be reduced to 3.9, 2.6, and 2.4 mm if treatment time was ≤ 4 min. With daily online correction and repositioning based on implanted fiducials, a significant reduction of PTV margins can be achieved. The use of an optimized workflow with faster treatment techniques such as volumetric modulated arc techniques (VMAT) could allow for a further decrease. (orig.)

  2. Systematic application of flame diagnostics techniques for performance and emissions development of modern combustion systems; Systematischer Einsatz der Flammendiagnostik fuer die Leistungs- und Emissionsentwicklung moderner Brennverfahren

    Energy Technology Data Exchange (ETDEWEB)

    Winklhofer, E.; Beidl, C.; Hirsch, A.; Piock, W. [AVL List GmbH, Graz (Austria)

    2004-07-01

    In engine engineering, the information and benefits gained from optical flame diagnostics, especially in the combination with thermodynamic and CFD analysis of airflow and combustion are well accepted. It is, however, a specific challenge to implement techniques which are well established in basic engine R and D into the processes of series development or engine calibration. Any technique taken over from successfull predevelopment applications, is expected to equally well support series development. But in order to do this, it must also be suited to easily blend into the procedures of standard multicylinder engine tests. Development speed and results quality improve consideraly, whenever engineers within their routine engine tests gain knowledge about and evaluation of flame properties which allow identification of possible improvements of combustion efficiency, power density and emissions in an early, upfront development phase. Diagnostic systems employed for such tasks make use of fiber optic sensors which in spark ignited engines may be implanted into the bodies of sensor spark plugs. Their mechanic, thermal and electric properties comply with those of the originals, thus enabling their continuous use on the test bed. The arrangement of standard fiber optic channels allows flame radiation monitoring either within the axial proximity of the sensor plug, or of the entire combustion chamber compression volume. Signal recording and signal analysis is accomplished with Visiolution system techniques. Test results are evaluated on the basis of Visiolution algorithms. Data reduction schemes provide numerical figures of merit, describing, e. g. direction, velocity and symmetry of a spark ignited flame kernel. When knock center distribution is analysed, actual distribution statistics are checked against best concept distributions, whenever diffusion flames are detected against expectations of ideal premixed flames, their position, timing and intensity is evaluated. Such

  3. Surveillance after prostate cancer radiotherapy

    International Nuclear Information System (INIS)

    Supiot, S.; Rio, E.; Clement-Colmou, K.; Bouchot, O.; Rigaud, J.

    2011-01-01

    Follow-up after prostate cancer radiotherapy aims at detecting local or metastatic relapse, as well as long-term toxicity, requiring adapted treatments. Several scientific societies have published guidelines including clinical, biological and imaging recommendations. More data suggest a role for aggressive salvage therapy in case of local failure following radiotherapy. An adequate follow-up is required for the sake of patients' safety, i.e. to a posteriori validate dose constraints and radiation technique in each radiotherapy department. (authors)

  4. A Modern Automatic Chamber Technique as a Powerful Tool for CH4 and CO2 Flux Monitoring

    Science.gov (United States)

    Mastepanov, M.; Christensen, T. R.; Lund, M.; Pirk, N.

    2014-12-01

    A number of similar systems were used for monitoring of CH4 and CO2 exchange by the automatic chamber method in a range of different ecosystems. The measurements were carried out in northern Sweden (mountain birch forest near Abisko, 68°N, 2004-2010), southern Sweden (forest bog near Hässleholm, 56°N, 2007-2014), northeastern Greenland (arctic fen in Zackenberg valley, 74°N, 2005-2014), southwestern Greenland (fen near Nuuk, 64°N, 2007-2014), central Svalbard (arctic fen near Longyearbyen, 78°N, 2011-2014). Those in total 37 seasons of measurements delivered not only a large amount of valuable flux data, including a few novel findings (Mastepanov et al., Nature, 2008; Mastepanov et al., Biogeosciences, 2013), but also valuable experience with implementation of the automatic chamber technique using modern analytical instruments and computer technologies. A range of high resolution CH4 analysers (DLT-100, FMA, FGGA - Los Gatos Research), CO2 analyzers (EGM-4, SBA-4 - PP Systems; Li-820 - Li-Cor Biosciences), as well as Methane Carbon Isotope Analyzer (Los Gatos Research) has shown to be suitable for precise measurements of fluxes, from as low as 0.1 mg CH4 m-1 d-1 (wintertime measurements at Zackenberg, unpublished) to as high as 2.4 g CH4 m-1 d-1 (autumn burst 2007 at Zackenberg, Mastepanov et al., Nature, 2008). Some of these instruments had to be customized to accommodate 24/7 operation in harsh arctic conditions. In this presentation we will explain some of these customizations. High frequency of concentration measurements (1 Hz in most cases) provides a unique opportunity for quality control of flux calculations; on the other hand, this enormous amount of data can be analyzed only using highly automated algorithms. A specialized software package was developed and improved through the years of measurements and data processing. This software automates the data flow from raw concentration data of different instruments and sensors and various status records

  5. Dosimetric and Radiobiologic Comparison of 3D Conformal Versus Intensity Modulated Planning Techniques for Prostate Bed Radiotherapy

    International Nuclear Information System (INIS)

    Koontz, Bridget F.; Das, Shiva; Temple, Kathy; Bynum, Sigrun; Catalano, Suzanne; Koontz, Jason I.; Montana, Gustavo S.; Oleson, James R.

    2009-01-01

    Adjuvant radiotherapy for locally advanced prostate cancer improves biochemical and clinical disease-free survival. While comparisons in intact prostate cancer show a benefit for intensity modulated radiation therapy (IMRT) over 3D conformal planning, this has not been studied for post-prostatectomy radiotherapy (RT). This study compares normal tissue and target dosimetry and radiobiological modeling of IMRT vs. 3D conformal planning in the postoperative setting. 3D conformal plans were designed for 15 patients who had been treated with IMRT planning for salvage post-prostatectomy RT. The same computed tomography (CT) and target/normal structure contours, as well as prescription dose, was used for both IMRT and 3D plans. Normal tissue complication probabilities (NTCPs) were calculated based on the dose given to the bladder and rectum by both plans. Dose-volume histogram and NTCP data were compared by paired t-test. Bladder and rectal sparing were improved with IMRT planning compared to 3D conformal planning. The volume of the bladder receiving at least 75% (V75) and 50% (V50) of the dose was significantly reduced by 28% and 17%, respectively (p = 0.002 and 0.037). Rectal dose was similarly reduced, V75 by 33% and V50 by 17% (p = 0.001 and 0.004). While there was no difference in the volume of rectum receiving at least 65 Gy (V65), IMRT planning significant reduced the volume receiving 40 Gy or more (V40, p = 0.009). Bladder V40 and V65 were not significantly different between planning modalities. Despite these dosimetric differences, there was no significant difference in the NTCP for either bladder or rectal injury. IMRT planning reduces the volume of bladder and rectum receiving high doses during post-prostatectomy RT. Because of relatively low doses given to the bladder and rectum, there was no statistically significant improvement in NTCP between the 3D conformal and IMRT plans.

  6. Dosimetric and radiobiologic comparison of 3D conformal versus intensity modulated planning techniques for prostate bed radiotherapy.

    Science.gov (United States)

    Koontz, Bridget F; Das, Shiva; Temple, Kathy; Bynum, Sigrun; Catalano, Suzanne; Koontz, Jason I; Montana, Gustavo S; Oleson, James R

    2009-01-01

    Adjuvant radiotherapy for locally advanced prostate cancer improves biochemical and clinical disease-free survival. While comparisons in intact prostate cancer show a benefit for intensity modulated radiation therapy (IMRT) over 3D conformal planning, this has not been studied for post-prostatectomy radiotherapy (RT). This study compares normal tissue and target dosimetry and radiobiological modeling of IMRT vs. 3D conformal planning in the postoperative setting. 3D conformal plans were designed for 15 patients who had been treated with IMRT planning for salvage post-prostatectomy RT. The same computed tomography (CT) and target/normal structure contours, as well as prescription dose, was used for both IMRT and 3D plans. Normal tissue complication probabilities (NTCPs) were calculated based on the dose given to the bladder and rectum by both plans. Dose-volume histogram and NTCP data were compared by paired t-test. Bladder and rectal sparing were improved with IMRT planning compared to 3D conformal planning. The volume of the bladder receiving at least 75% (V75) and 50% (V50) of the dose was significantly reduced by 28% and 17%, respectively (p = 0.002 and 0.037). Rectal dose was similarly reduced, V75 by 33% and V50 by 17% (p = 0.001 and 0.004). While there was no difference in the volume of rectum receiving at least 65 Gy (V65), IMRT planning significant reduced the volume receiving 40 Gy or more (V40, p = 0.009). Bladder V40 and V65 were not significantly different between planning modalities. Despite these dosimetric differences, there was no significant difference in the NTCP for either bladder or rectal injury. IMRT planning reduces the volume of bladder and rectum receiving high doses during post-prostatectomy RT. Because of relatively low doses given to the bladder and rectum, there was no statistically significant improvement in NTCP between the 3D conformal and IMRT plans.

  7. The comparison of 5-field conformal radiotherapy techniques for the treatment of prostate cancer: The best for femoral head sparing

    International Nuclear Information System (INIS)

    Zare, Mahkameh; Lashkari, Marzieh; Ghalehtaki, Reza; Ghasemi, Arash; Dehghan Manshadi, Hamidreza; Mir, Ali; Noorollahi, Somayeh; Alamolhoda, Mahboobeh

    2016-01-01

    External radiotherapy is a standard treatment procedure for localized prostate cancer. Given the relatively high long term survival treatment complications have been brought in center of attention. In this planning study, between 2012 and 2014, CT simulation data of 90 consecutive high-risk prostate cancer patients were collected. In the first phase, all were planned for whole pelvis irradiation up to 46Gy in 23 daily fractions. In the second phase, only the prostate gland was the target of radiation. Next, the subjects were divided randomly into three groups and each received a unique 5field conformal radiation plan including Plan A (Gantry angle: 0, 60, 120, 240, and 300), Plan B (Gantry angles: 0, 90, 120, 240, and 270) and Plan C (Gantry angles: 0, 60, 90, 270, and 300). The total dose was 70Gy. For each patient, the rectum, bladder, and both femoral heads were contoured as the at risk organs (OAR). From dose volume histograms, the proportional dose of PTV V100, the bladder and rectum V80 and V90 and femoral head V50 and V100 were calculated in all subjects and compared across plans. A statistically significant difference in the femoral head V50 and V100 was found between our studied 5field plans so that in Plan A (beam angles: 0, 60, 120, 240 and 300) less dose was received by both heads of femur. This study suggests that 5 field treatment planning including an anterior, two anterior oblique and two posterior oblique portals to be more proper for 3D conformal radiotherapy in order to spare femoral head with acceptable PTV coverage, and bladder and rectal doses.

  8. Radiotherapy of the periarthritis humeroscapularis. Indication, technique and radiation results; Periarthritis humeroscapularis (PHS). Indikation, Technik und Bestrahlungsergebnisse

    Energy Technology Data Exchange (ETDEWEB)

    Keilholz, L. [Erlangen-Nuernberg Univ., Erlangen (Germany). Strahlentherapeutische Klinik; Seegenschmiedt, M.H. [Erlangen-Nuernberg Univ., Erlangen (Germany). Strahlentherapeutische Klinik; Kutzki, D. [Erlangen-Nuernberg Univ., Erlangen (Germany). Strahlentherapeutische Klinik; Sauer, R. [Erlangen-Nuernberg Univ., Erlangen (Germany). Strahlentherapeutische Klinik

    1995-07-01

    106 patients with clinically evident disease of PHS were treated between January 1987 and May 1991. 73/106 patients had a continuous follow-up. 16/73 patients showed typical symptoms on both shoulders; therefore a total of 89 shoulders were examined in this investigation. A daily dose of 0.5 Gy was given for 3 times a week and a total dose of 3.0 Gy. After 8 weeks a second treatment course was performed. In follow-up the subjective (pain) and objective (limitation of abduction) symptoms were classified in 3 grade scales. A marked pain reduction and an improved mobility (abduction of at least 20 degrees more than before radiation) could be observed in 72/89 shoulders (81%). 44/89 shoulders (49%) showed an excellent response and were competely free of pain and impairment of motion. Radiotherapy of acute or subacute Periarthritis humeroscapularis is a very effective treatment if radiation starts within the first year of symptoms and if it is supported by physiotherapy. (orig.) [Deutsch] Im Zeitraum vom 1.1.1987 bis 1.5.1991 wurden an der Klinik fuer Strahlentherapie, Erlangen, 106 Patienten wegen einer Periarthritis humeroscapularis (PHS) behandelt. 73 Patienten konnten regelmaessig nachuntersucht werden. Von diesen litten 16 an einer beidseitigen PHS, so dass insgesamt 89 Lokalisationen untersucht wurden. Es wurden zwei Bestrahlungsserien (im Abstand von acht Wochen) mit einer Referenzdosis von 3 Gy pro Seite, bei einer Einzeldosis von 0,5 Gy, dreimal woechentlich verabreicht. Die Beurteilung des Therapieerfolges erfolgte nach drei subjektiven Beschwerdegraden und drei objektiven Graden. Eine Besserung der subjektiven Beschwerden um einen Grad und er Schultergelekbeweglichkeit (Abduktion) um mindestens 20 Grad trat bei 72 behandelten Schultergelenken (81%) auf. Bei 44 Schultergelenken (49%) erreichten wir eine komplette Beschwerdefreiheit. Die Radiotherapie der akuten wie subakuten Periarthritis humeroscapularis ist hocheffektiv, insbesondere dann, wenn Bestrahlung

  9. Evaluation of Sentinel Lymph Node Dose Distribution in 3D Conformal Radiotherapy Techniques in 67 pN0 Breast Cancer Patients.

    Science.gov (United States)

    Witucki, Gerlo; Degregorio, Nikolaus; Rempen, Andreas; Schwentner, Lukas; Bottke, Dirk; Janni, Wolfgang; Ebner, Florian

    2015-01-01

    Introduction. The anatomic position of the sentinel lymph node is variable. The purpose of the following study was to assess the dose distribution delivered to the surgically marked sentinel lymph node site by 3D conformal radio therapy technique. Material and Method. We retrospectively analysed 70 radiotherapy (RT) treatment plans of consecutive primary breast cancer patients with a successful, disease-free, sentinel lymph node resection. Results. In our case series the SN clip volume received a mean dose of 40.7 Gy (min 28.8 Gy/max 47.6 Gy). Conclusion. By using surgical clip markers in combination with 3D CT images our data supports the pathway of tumouricidal doses in the SN bed. The target volume should be defined by surgical clip markers and 3D CT images to give accurate dose estimations.

  10. A Dosimetric Comparison of Accelerated Partial Breast Irradiation Techniques: Multicatheter Interstitial Brachytherapy, Three-Dimensional Conformal Radiotherapy, and Supine Versus Prone Helical Tomotherapy

    International Nuclear Information System (INIS)

    Patel, Rakesh R.; Becker, Stewart J.; Das, Rupak K.; Mackie, Thomas R.

    2007-01-01

    Purpose: To compare dosimetrically four different techniques of accelerated partial breast irradiation (APBI) in the same patient. Methods and Materials: Thirteen post-lumpectomy interstitial brachytherapy (IB) patients underwent imaging with preimplant computed tomography (CT) in the prone and supine position. These CT scans were then used to generate three-dimensional conformal radiotherapy (3D-CRT) and prone and supine helical tomotherapy (PT and ST, respectively) APBI plans and compared with the treated IB plans. Dose-volume histogram analysis and the mean dose (NTD mean ) values were compared. Results: Planning target volume coverage was excellent for all methods. Statistical significance was considered to be a p value mean dose of 1.3 Gy 3 and 1.2 Gy 3 , respectively. Both of these methods were statistically significantly lower than the supine external beam techniques. Overall, all four methods yielded similar low doses to the heart. Conclusions: The use of IB and PT resulted in greater normal tissue sparing (especially ipsilateral breast and lung) than the use of supine external beam techniques of 3D-CRT or ST. However, the choice of APBI technique must be tailored to the patient's anatomy, lumpectomy cavity location, and overall treatment goals

  11. Modern Biology

    OpenAIRE

    ALEKSIC, Branko

    2014-01-01

    The purpose of this course is to learn the philosophy, principles, and techniques of modern biology. The course is particularly designed for those who have not learned biology previously or whose major is other than biology, and who may think that they do not need to know any biology at all. The topics are covered in a rather general, overview manner, but certain level of diligence in grasping concepts and memorizing the terminology is expected.

  12. Sci-Fri PM: Radiation Therapy, Planning, Imaging, and Special Techniques - 03: The Potential Benefit Of Esophageal Sparing During Palliative Radiotherapy For Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Granton, Patrick V.; Palma, David A.; Louie, Alexander V. [Department of Radiation Oncology, London Health Sciences Centre, Department of Radiation Oncology, London Health Sciences Centre, Department of Radiation Oncology, London Health Sciences Centre (United Kingdom)

    2016-08-15

    Puropose: Palliative radiotherapy is an effective technique to alleviate systems of disease burden in late-stage lung cancer patients. Previous randomized controlled studies demonstrated a survival benefit in patients with good performance status at radiation doses of 35Gy10 or greater but with an increased incidence of esophagitis. The objective of this planning study was to assess the potential impact of esophageal-sparing IMRT (ES-IMRT) compared to the current standard of care using parallel-opposed pair beams (POP). Methods: In this study, 15 patients with lung cancer treated to a dose of 30Gy in 10 fractions between August 2015 and January 2016 were identified. Radiation treatment plans were optimized using ES-IMRT by limiting the max esophagus point dose to 24Gy. Using published Lyman-Kutcher-Burman normal tissue complication probabilities (LKB-NTCP) models, both plans were evaluated for the likelihood of esophagitis (≥ grade 2) and pneumonitis (≥ grade 2). Results: Using ES-IMRT, the median esophageal and lung mean doses reduced from 16 and 8Gy to 7 and 7Gy, respectively. Using the LKB models, the theoretical probability of symptomatic esophagitis and pneumonitis reduced from 13 to 1%, and from 5 to 3%, respectively. The median NTD mean for the GTV and PTV of the clinically approved POP plans compared to the ES-IMRT plans were similar. Conclusions: Advanced radiotherapy techniques such as ES-IMRT may have clinical utility in reducing treatment-related toxicity in advanced lung cancer patients. Our data suggests that the rate of esophagitis can be reduced without compromising tumour control.

  13. Intraoperative radiotherapy in breast cancer: literature review

    International Nuclear Information System (INIS)

    Alfaro Hidalgo, Sabrina A.

    2013-01-01

    A literature review was performed on intraoperative radiotherapy of breast cancer. The strength and attractiveness is established of techniques of partial irradiation in the treatment of breast cancer. The benefit is originated to restrict the area immediate of radiotherapy to the tumor bed or quadrant index and identifying the benefit of being applied during the radiotherapy while surgical lumpectomy. The impact of local recurrence has been established using intraoperative radiotherapy. The advantages of intraoperative radiotherapy was compared in the management of the conservative surgery in early stages of breast cancer with external radiotherapy. Different methods of intraoperative radiotherapy have been compared and individual impact on local recurrence ranges. Intraoperative radiotherapy has had many advantages: radiobiological, technical, clinical, psychological and economical in the handling of conservative surgery in early stages of breast cancer, compared with external radiotherapy [es

  14. Modern sample preparation techniques for gas chromatography-mass spectrometry analysis of environmental markers of chemical warfare agents use

    NARCIS (Netherlands)

    Terzic, O.; de Voogt, P.; Banoub, J.

    2014-01-01

    The chapter introduces problematics of on-site chemical analysis in the investigations of past chemical warfare agents (CWA) events. An overview of primary environmental degradation pathways of CWA leading to formation of chemical markers of their use is given. Conventional and modern sample

  15. Application of modern tools and techniques to maximize engineering productivity in the development of orbital operations plans for the space station progrm

    Science.gov (United States)

    Manford, J. S.; Bennett, G. R.

    1985-01-01

    The Space Station Program will incorporate analysis of operations constraints and considerations in the early design phases to avoid the need for later modifications to the Space Station for operations. The application of modern tools and administrative techniques to minimize the cost of performing effective orbital operations planning and design analysis in the preliminary design phase of the Space Station Program is discussed. Tools and techniques discussed include: approach for rigorous analysis of operations functions, use of the resources of a large computer network, and providing for efficient research and access to information.

  16. Comparative study of different Al{sub 2}O{sub 3}:C dosimeters using OSL technique for dosimetry on Volumetric Modulated Arc Radiotherapy Treatment (VMAT); Estudo comparativo de diferentes dosimetros de Al{sub 2}O{sub 3}:C pela tecnica OSL na dosimetria de tratamentos Radioterapicos por Arco Modulado Volumetrico (VMAT)

    Energy Technology Data Exchange (ETDEWEB)

    Villani, Daniel; Campos, LetIcia L., E-mail: dvillani@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Mancini, Anselmo; Haddad, Cecilia M.K. [Hospital Sirio-Libanes, Sao Paulo, SP (Brazil). Centro de Radioterapia

    2016-07-01

    In modern radiotherapy, the VMAT technique has become a successful treatment alternative. Due to its complexity, a quality assurance program must be established by evaluating, among other items, the dosimetric factors. This paper aims to compare the performance between the OSL aluminum oxide (Al{sub 2}O{sub 3}:C) nanoDot™ dosimeters (Inlight™ system) manufactured by Landauer Inc. and TLD-500 Al{sub 2}O{sub 3}:C dosimeters manufactured by Rexon™ for VMAT dosimetry using an anthropomorphic phantom. The results showed that both type of Al{sub 2}O{sub 3}:C dosimeters presented good repeatability and agreement between the doses measured and calculated by planning system. However, the need of sophisticated readers to OSL analysis of the TLD-500, turns it less practical for routine usage, comparing to Inlight™ system. (author)

  17. The strategy of therapy of the axilla in early cancer. Surgery or radiotherapy

    International Nuclear Information System (INIS)

    Izuo, Masaru

    1998-01-01

    The therapy of the axillary lymph node in early breast cancer was assessed perspectively. Recently, axillary irradiation was carried out and compared with surgery. Radiotherapy was not evaluated more successful. To carry out in accordance with the present guide line, so called ''modern technique'' or ''modern dosage schedule'', radiotherapy of the axilla is effective as well as surgery. We have many agreements that the rate of incidence of complication associated with irradiation was decreased in accordance with ''modern technique''. It is reasonable to radiate additionally after the selection by the ''node sampling'' in the sense of decreasing unnecessary irradiation. But it is not sufficient in their reliability, it is hard to expect this method getting more popular than now. We cannot find any difference in the effect of the treatment itself between present dissection and radiotherapy. However we have many agreements that axillary dissection may give the information about n-stage, and the contribution to the suitable selection to the prognosis factor and adjuvant chemotherapy was not so less even in early cancer. Some early cancers (non-invasive carcinoma or micro carcinoma) will not need the axillary therapy. It is one of the options ''to combine mastectomy under local anesthesia and radiotherapy'' in close cooperation with the skilled radiologist. (K.H.) 120 refs

  18. Study and establishment of a computer program for radiotherapy treatment planning development

    International Nuclear Information System (INIS)

    Djennaoui, N.

    1987-02-01

    The modern radiotherapy requires the use of computers. In addition to their accuracy, computers involve an appreciable saving of time in the calculation of isodoses, permitting us to change several times a technique in order to choose the best dose distribution for each case of tumor. The aim of this work was to set a computer program calculating a suitable dose distribution for a given treatment. The algorithm of calculation of the depth dose used in our program permits us to calculate the dose distribution for all photon energies used in radiotherapy, whatever are the energy and modification of the field by the use of wedge filters or bolus [fr

  19. An enhanced ionising radiation monitoring and detecting technique in radiotherapy units of hospitals using wireless sensor networks

    International Nuclear Information System (INIS)

    Ali, Peter

    2017-01-01

    In this paper, a solution of ionising radiation monitoring based on the concept of Wireless Sensor Network (WSN), is presented. Radiation dose rate measured by the sensor node is sent to the monitoring station through ZigBee wireless network operated on 2.4 GHz unlicensed Industrial Scientific Medical (ISM) band. The system is calibrated for use for ionizing radiation dose rate range of between amount of ionising radiation observed in radiotherapy unit of a hospital and 1.02 mSv/h. Power consumption of the sensor node is kept low by operating the node ZigBee radio with low duty cycle: i.e. by keeping the radio awake only during data transmission/reception. Two ATmega8 microcontrollers, one each for sensor node and the monitoring station, are programmed to perform interfacing, data processing, and control functions. The system range of coverage is 124m for outdoor (line of site) deployment and 56.8m for indoor application where 5 brick walls separated the sensor node and the monitoring station. Range of coverage of the system is extendable via the use of ZigBee router (s)

  20. A comparison of optic nerve dosimetry in craniospinal radiotherapy planned and treated with conventional and intensity modulated techniques

    International Nuclear Information System (INIS)

    Rene, Nicholas J.; Brodeur, Marylene; Parker, William; Roberge, David; Freeman, Carolyn

    2010-01-01

    Background and purpose: Some CNS tumours present leptomeningeal dissemination. Craniospinal radiotherapy is complex and recurrences may occur at sites of target volume underdosage. IMRT, being highly conformal to the target, could theoretically underdose the optic nerves if they are not specifically targeted leading to optic nerve recurrences. We analyzed optic nerve dosimetry when they are not specifically targeted. Materials and methods: We designed 3D-conformal and tomotherapy plans for our last five patients treated to the craniospinal axis, not including the optic nerves in the target volume. We analyzed the dose delivered to the optic nerves, to the anterior and posterior half of the optic nerves, and to a theoretical optic nerve-PTV. Results: The dose delivered to the optic nerves was similar for both plans in all patients (V95% close to 100%) except one in whom tomotherapy considerably underdosed the anterior optic nerves. The dose to the optic nerve-PTV was lower with tomotherapy in all patients. Conclusion: Despite not intentionally targeting the optic nerves, the dose to the optic nerves with IMRT was similar to 3D-conformal plans in most cases but left no margin for setup error. In individual cases the anterior half of the optic nerves could be significantly underdosed.

  1. Whither radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Ross, W M

    1987-03-01

    The 1986 Glyn Evans Memorial Lecture, given at the Joint Provincial Meeting of the Royal College of Radiologists, Sheffield, September 1986, sketches an outline of the history of radiotherapy and discusses the future development of the art. Topics included are siting of centres, training needs, the relationship of radiotherapy to other medical specialities, and the advantages and disadvantages of radiotherapy practitioners forming a separate medical College. (U.K.)

  2. Detecting and Treating Cervical Cancer Using Diagnostic Imaging Techniques and Radiotherapy. IAEA Support to Latin America and the Caribbean

    International Nuclear Information System (INIS)

    Dixit, Aabha

    2016-01-01

    The diagnosis and treatment of cervical cancer are an important area of cooperation in the field of human health between Member States in the Latin America and the Caribbean region and the IAEA. Nuclear medicine and radiation therapy offer rapid diagnosis and effective treatment for various types of cancer. Cervical cancer is usually curable if caught early and treated. Member States in the region have shown a very strong commitment to enhancing access to radiation oncology and to assuring the quality of treatment. Many are focusing on education and training and the modernization of clinical infrastructure in national institutions responsible for health care and services.

  3. Theory, simulation and experiments for precise deflection control of radiotherapy electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa, R.; Leiva, J.; Moncada, R.; Rojas, L.; Santibanez, M.; Valente, M.; Young, H. [Universidad de la Frontera, Centro de Fisica e Ingenieria en Medicina, Av. Francisco Salazar 1145, Casilla 54-D, Temuco (Chile); Velasquez, J. [Universidad de la Frontera, Departamento de Ciencias Fisicas, Av. Francisco Salazar 1145, Casilla 54-D, Temuco (Chile); Zelada, G. [Clinica Alemana de Santiago, Av. Vitacura 5951, 13132 Vitacura, Santiago (Chile); Astudillo, R., E-mail: rodolfo.figueroa@ufrontera.cl [Hospital Base de Valdivia, C. Simpson 850, XIV Region de los Rios, Valdivia (Chile)

    2017-10-15

    Conventional radiotherapy is mainly applied by linear accelerators. Although linear accelerators provide dual (electron/photon) radiation beam modalities, both of them are intrinsically produced by a megavoltage electron current. Modern radiotherapy treatment techniques are based on suitable devices inserted or attached to conventional linear accelerators. Thus, precise control of delivered beam becomes a main key issue. This work presents an integral description of electron beam deflection control as required for novel radiotherapy technique based on convergent photon beam production. Theoretical and Monte Carlo approaches were initially used for designing and optimizing devices components. Then, dedicated instrumentation was developed for experimental verification of electron beam deflection due to the designed magnets. Both Monte Carlo simulations and experimental results support the reliability of electrodynamics models used for predict megavoltage electron beam control. (Author)

  4. Theory, simulation and experiments for precise deflection control of radiotherapy electron beams

    International Nuclear Information System (INIS)

    Figueroa, R.; Leiva, J.; Moncada, R.; Rojas, L.; Santibanez, M.; Valente, M.; Young, H.; Velasquez, J.; Zelada, G.; Astudillo, R.

    2017-10-01

    Conventional radiotherapy is mainly applied by linear accelerators. Although linear accelerators provide dual (electron/photon) radiation beam modalities, both of them are intrinsically produced by a megavoltage electron current. Modern radiotherapy treatment techniques are based on suitable devices inserted or attached to conventional linear accelerators. Thus, precise control of delivered beam becomes a main key issue. This work presents an integral description of electron beam deflection control as required for novel radiotherapy technique based on convergent photon beam production. Theoretical and Monte Carlo approaches were initially used for designing and optimizing devices components. Then, dedicated instrumentation was developed for experimental verification of electron beam deflection due to the designed magnets. Both Monte Carlo simulations and experimental results support the reliability of electrodynamics models used for predict megavoltage electron beam control. (Author)

  5. Comparison of rectal volume definition techniques and their influence on rectal toxicity in patients with prostate cancer treated with 3D conformal radiotherapy: a dose-volume analysis

    International Nuclear Information System (INIS)

    Onal, Cem; Topkan, Erkan; Efe, Esma; Yavuz, Melek; Sonmez, Serhat; Yavuz, Aydin

    2009-01-01

    To evaluate the impact of four different rectum contouring techniques and rectal toxicities in patients with treated with 3D conformal radiotherapy (3DCRT). Clinical and dosimetric data were evaluated for 94 patients who received a total dose 3DCRT of 70 Gy, and rectal doses were compared in four different rectal contouring techniques: the prostate-containing CT sections (method 1); 1 cm above and below the planning target volume (PTV) (method 2); 110 mm starting from the anal verge (method 3); and from the anal verge to the sigmoid flexure (method 4). The percentage of rectal volume receiving RT doses (30–70 Gy) and minimum, mean rectal doses were assessed. Median age was 69 years. Percentage of rectal volume receiving high doses (≥ 70 Gy) were higher with the techniques that contoured smaller rectal volumes. In methods 2 and 3, the percentage of rectal volume receiving ≥ 70 Gy was significantly higher in patients with than without rectal bleeding (method 2: 30.8% vs. 22.5%, respectively (p = 0.03); method 3: 26.9% vs. 18.1%, respectively (p = 0.006)). Mean rectal dose was significant predictor of rectal bleeding only in method 3 (48.8 Gy in patients with bleeding vs. 44.4 Gy in patients without bleeding; p = 0.02). Different techniques of rectal contouring significantly influence the calculation of radiation doses to the rectum and the prediction of rectal toxicity. Rectal volume receiving higher doses (≥ 70 Gy) and mean rectal doses may significantly predict rectal bleeding for techniques contouring larger rectal volumes, as was in method 3

  6. Could 3-D conformal radiotherapy improve the overall survival for non-small cell lung cancer?

    International Nuclear Information System (INIS)

    Giraud, P.; Helfre, S.; Lavole, A.; Rosenwald, J.C.; Cosset, J.M.

    2002-01-01

    The conformal radiotherapy approach, three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT), is based on modern imaging modalities, efficient 3-D treatment planning systems, sophisticated immobilization devices and demanding quality assurance and treatment verification. The main goal of conformal radiotherapy is to ensure a high dose distribution tailored to the limits of the target volume while reducing exposure of healthy tissues. These techniques would then allow a further dose escalation increasing local control and survival. Non-small cell lung cancer (NSCLC) is one of the most difficult malignant tumors to be treated. It combines geometrical difficulties due to respiratory motion, and number of low tolerance neighboring organs, and dosimetric difficulties because of the presence of huge inhomogeneities. This localization is an attractive and ambitious example for the evaluation of new techniques. However, the published clinical reports in the last years described very heterogeneous techniques and, in the absence of prospective randomized trials, it is somewhat difficult at present to evaluate the real benefits drawn from those conformal radiotherapy techniques. After reviewing the rationale for 3DCRT for NSCLC, this paper will describe the main studies of 3DCRT, in order to evaluate its impact on lung cancer treatment Then the current state-of-the-art of IMRT and the last technical and therapeutic innovations in NSCL will be discussed. (authors)

  7. [Current status and potential perspectives in classical radiotherapy technology].

    Science.gov (United States)

    Dabić-Stanković, Kata M; Stanković, Jovan B; Radosević-Jelić, Ljiljana M

    2004-01-01

    After purchase of radiotherapy equipment in 2003, classic radiation therapy in Serbia will reach the highest world level. In order to define the highest standards in radiation technology, we analyzed the current status and potential perspectives of radiation therapy. An analysis of present situation in the USA, assumed as the most developed in the world, was done. Available data, collected in the last 3 years (equipment assortment, therapy modalities, workload and manpower) for 284 radiotherapy centers, out of potential 2050, were analyzed. Results were presented as crude percentage and matched to point current status. The analysis showed that CLINAC accelerators are the most popular (82.7%), as well as, ADAC (43.7%) and Focus (CMS) (27.4%) systems for therapy planning. Movement towards virtual simulation is evident (59.3%), although classic "simulation" is not fully eliminated from the radiotherapy chain. The most popular brachytherapy afterloader is Microselectron HDR (71%). About 64.4% centers use IMPAC communication/verification/record system that seems more open than Varis. All centers practice modern radiotherapy modalities and techniques (CPRT, IMRT, SRS/SRT, TBI, IORT, IVBHRT, HDR BHRT, etc.). CT and MRI availability is out of question, but PET is available in 3% of centers, however this percentage is rapidly growing. Up to 350 new patients per year are treated by one accelerator (about 35 pts. a day). Centers are relatively small and utilize 2-3 accelerators on average. Average FTE staffing norm is 4 radiation oncologists, 2-3 medical radiotherapy physicists, about 3 certified medical dosimetrists and about 6 radiotherapy technologists. In the past 5 years relative stagnation in classic radiotherapy has been observed. In spite of substantial investments in technology and consequent improvements, as well as wide introduction of computers in radiotherapy, radiotherapy results have not changed significantly. Vendor developement strategies do not point that

  8. Breast radiotherapy with inclusion of internal mammary nodes: a comparison of techniques with three-dimensional planning

    International Nuclear Information System (INIS)

    Severin, Diane; Connors, Sherry; Thompson, Heather; Rathee, Satyapal; Stavrev, Pavel; Hanson, John

    2003-01-01

    Purpose: To compare the partially wide tangent (PWT) technique of breast and internal mammary chain irradiation with photon/electron (P/E) and standard tangent (ST) techniques in terms of dose homogeneity within breast and the dose to critical structures such as the heart and lung. Methods and Materials: Sixteen left breast cancer patients underwent CT simulation. The breasts, lungs, heart, and internal mammary chain were contoured and treatment plans generated on a three-dimensional planning system (Helax-TMS). Results: The mean dose to the left breast volume with the ST, P/E, and PWT techniques was 94.7%, 98.4%, and 96.5%, respectively (p=0.029). The left lung received the lowest mean dose with the ST technique (13.9%) compared with PWT (22.8%) and P/E (24.3%). The internal mammary chain volume was most consistently treated with the PWT (mean dose 99%) vs. P/E (86%) and ST (38.4%) techniques. The heart received the least dose with ST (mean dose 6.7%) vs. PWT (10.3%) and P/E (19%). The PWT treated the greatest amount of contralateral breast (mean dose 5.8%) vs. ST (3.2%) vs. P/E (2.8%). Conclusion: The PWT technique treats the internal mammary chain with acceptable toxicity to major organs, especially the heart, and with reasonable dose homogeneity in patients with mastectomy or intact breasts

  9. Fetal dose from radiotherapy photon beams: Physical basis, techniques to estimate radiation dose outside of the treatment field, biological effects and professional considerations

    International Nuclear Information System (INIS)

    Stovell, Marilyn; Blackwell, C. Robert

    1997-01-01

    Purpose/Objective: The presentation will review: 1. The physical basis of radiation dose outside of the treatment field. 2. Techniques to estimate and reduce fetal dose. 3. Clinical examples of fetal dose estimation and reduction. 4. Biological effects of fetal irradiation. 5. Professional considerations. Approximately 4000 women per year in the United States require radiotherapy during pregnancy. This report presents data and techniques that allow the medical physicist to estimate the radiation dose the fetus will receive and to reduce this dose with appropriate shielding. Out-of-beam data are presented for a variety of photon beams, including cobalt-60 gamma rays and x rays from 4 to 18 MV. Designs for simple and inexpensive to more complex and expensive types of shielding equipment are described. Clinical examples show that proper shielding can reduce the radiation dose to the fetus by 50%. In addition, a review of the biological aspects of irradiation enables estimates of the risks of lethality, growth retardation, mental retardation, malformation, sterility, cancer induction, and genetic defects to the fetus. A summary of professional considerations/recommendations is also provided as a guide for the radiation oncologist and medical physicist

  10. SU-E-T-332: Dosimetric Impact of Photon Energy and Treatment Technique When Knowledge Based Auto-Planning Is Implemented in Radiotherapy of Localized Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Z; Kennedy, A [Sarah Cannon, Nashville, TN (United States); Larsen, E; Grow, A; Hayes, C; Balamucki, C [North Florida Cancer Center, Gainesville, FL (United States); Salmon, H; Thompson, M [Lake City Cancer Center, Lake City, FL (United States)

    2015-06-15

    Purpose: The aim of this study was to investigate the dosimetric impact of the combination of photon energy and treatment technique on radiotherapy of localized prostate cancer when knowledge based planning was used. Methods: A total of 16 patients with localized prostate cancer were retrospectively retrieved from database and used for this study. For each patient, four types of treatment plans with different combinations of photon energy (6X and 10X) and treatment techniques (7-field IMRT and 2-arc VMAT) were created using a prostate DVH estimation model in RapidPlan™ and Eclipse treatment planning system (Varian Medical System). For any beam arrangement, DVH objectives and weighting priorities were generated based on the geometric relationship between the OAR and PTV. Photon optimization algorithm was used for plan optimization and AAA algorithm was used for final dose calculation. Plans were evaluated in terms of the pre-defined dosimetric endpoints for PTV, rectum, bladder, penile bulb, and femur heads. A Student’s paired t-test was used for statistical analysis and p > 0.05 was considered statistically significant. Results: For PTV, V95 was statistically similar among all four types of plans, though the mean dose of 10X plans was higher than that of 6X plans. VMAT plans showed higher heterogeneity index than IMRT plans. No statistically significant difference in dosimetry metrics was observed for rectum, bladder, and penile bulb among plan types. For left and right femur, VMAT plans had a higher mean dose than IMRT plans regardless of photon energy, whereas the maximum dose was similar. Conclusion: Overall, the dosimetric endpoints were similar regardless of photon energy and treatment techniques when knowledge based auto planning was used. Given the similarity in dosimetry metrics of rectum, bladder, and penile bulb, the genitourinary and gastrointestinal toxicities should be comparable among the selections of photon energy and treatment techniques.

  11. Bowel sparing in pediatric cranio-spinal radiotherapy: a comparison of combined electron and photon and helical TomoTherapy techniques to a standard photon method

    International Nuclear Information System (INIS)

    Harron, Elizabeth; Lewis, Joanne

    2012-01-01

    The aim of this study was to compare the dose to organs at risk (OARs) from different craniospinal radiotherapy treatment approaches available at the Northern Centre for Cancer Care (NCCC), with a particular emphasis on sparing the bowel. Method: Treatment plans were produced for a pediatric medulloblastoma patient with inflammatory bowel disease using 3D conformal 6-MV photons (3DCP), combined 3D 6-MV photons and 18-MeV electrons (3DPE), and helical photon TomoTherapy (HT). The 3DPE plan was a modification of the standard 3DCP technique, using electrons to treat the spine inferior to the level of the diaphragm. The plans were compared in terms of the dose-volume data to OARs and the nontumor integral dose. Results: The 3DPE plan was found to give the lowest dose to the bowel and the lowest nontumor integral dose of the 3 techniques. However, the coverage of the spine planning target volume (PTV) was least homogeneous using this technique, with only 74.6% of the PTV covered by 95% of the prescribed dose. HT was able to achieve the best coverage of the PTVs (99.0% of the whole-brain PTV and 93.1% of the spine PTV received 95% of the prescribed dose), but delivered a significantly higher integral dose. HT was able to spare the heart, thyroid, and eyes better than the linac-based techniques, but other OARs received a higher dose. Conclusions: Use of electrons was the best method for reducing the dose to the bowel and the integral dose, at the expense of compromised spine PTV coverage. For some patients, HT may be a viable method of improving dose homogeneity and reducing selected OAR doses.

  12. Evaluation of the dosimetric consequences of adding a single asymmetric or MLC shaped field to a tangential breast radiotherapy technique

    International Nuclear Information System (INIS)

    Richmond, Neil D.; Turner, Robert N.; Dawes, Peter J.D.K.; Lambert, Geoff D.; Lawrence, Gill P.

    2003-01-01

    Fifteen consecutive patients had standard treatment plans generated using our departmental protocol and two further plans produced using either an asymmetric, or MLC shaped additional field, from each tangential direction. The mean percentage of the PTV receiving over 107% of the isocentre dose was 19.8% for the standard planned patients (95% confidence interval 12.3-27.4%). This was reduced to 6.0% for the asymmetric field technique (95% confidence interval 4.1-8.0%) and 5.3% for the MLC technique (95% confidence interval 2.8-7.7%). These high dose volume reductions were therefore significant at the 95% confidence level. It was also concluded that both alternative planning techniques offer the greatest potential when the standard plan indicated that more than 20% of the PTV would receive greater than 107% of the prescribed dose. Under these circumstances the segmented field techniques led to a reduction of at least 15 percentage points in this figure. It is this group of patients who stand to benefit most from application of these simple additional field techniques

  13. [Radiotherapy of oropharynx carcinoma].

    Science.gov (United States)

    Servagi Vernat, S; Tochet, F; Vieillevigne, L; Pointreau, Y; Maingon, P; Giraud, P

    2016-09-01

    Indication, doses, technique of radiotherapy and concomitant chemotherapy for oropharynx carcinoma are presented. The recommendations for delineation of the target volumes and organs at risk are detailed. Copyright © 2016 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

  14. Postoperative radiotherapy for prostate cancer. Morbidity of local-only or local-plus-pelvic radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Waldstein, Cora; Poetter, Richard; Widder, Joachim; Goldner, Gregor [Medical University of Vienna, Department of Radiation Oncology, Comprehensive Cancer Center, General Hospital of Vienna, Vienna (Austria); Doerr, Wolfgang [Medical University of Vienna, Department of Radiation Oncology, Comprehensive Cancer Center, General Hospital of Vienna, Vienna (Austria); Medical University of Vienna, Christian-Doppler Laboratory for Medical Radiation Research for Radiooncology, Vienna (Austria)

    2018-01-15

    The aim of this work was to characterise actuarial incidence and prevalence of early and late side effects of local versus pelvic three-dimensional conformal postoperative radiotherapy for prostate cancer. Based on a risk-adapted protocol, 575 patients received either local (n = 447) or local-plus-pelvic (n = 128) radiotherapy. Gastrointestinal (GI) and genitourinary (GU) side effects (≥grade 2 RTOG/EORTC criteria) were prospectively assessed. Maximum morbidity, actuarial incidence rate, and prevalence rates were compared between the two groups. For local radiotherapy, median follow-up was 68 months, and the mean dose was 66.7 Gy. In pelvic radiotherapy, the median follow-up was 49 months, and the mean local and pelvic doses were 66.9 and 48.3 Gy respectively. Early GI side effects ≥ G2 were detected in 26% and 42% of patients respectively (p < 0.001). Late GI adverse events were detected in 14% in both groups (p = 0.77). The 5-year actuarial incidence rates were 14% and 14%, while the prevalence rates were 2% and 0% respectively. Early GU ≥ G2 side effects were detected in 15% and 16% (p = 0.96), while late GU morbidity was detected in 18% and 24% (p = 0.001). The 5-year actuarial incidence rates were 16% and 35% (p = 0.001), while the respective prevalence rates were 6% and 8%. Despite the low prevalence of side effects, postoperative pelvic radiotherapy results in significant increases in the actuarial incidence of early GI and late GU morbidity using a conventional 4-field box radiotherapy technique. Advanced treatment techniques like intensity-modulated radiotherapy (IMRT) or volumetric modulated arc radiotherapy (VMAT) should therefore be considered in pelvic radiotherapy to potentially reduce these side effects. (orig.) [German] Ziel der vorgestellten Arbeit ist es, die Haeufigkeit frueher und spaeter Nebenwirkungen nach postoperativer Bestrahlung von Prostatakarzinompatienten zu analysieren. Verglichen wurden dabei die Nebenwirkungen von lokaler

  15. The evolution of rectal and urinary toxicity and immune response in prostate cancer patients treated with two three-dimensional conformal radiotherapy techniques

    International Nuclear Information System (INIS)

    Vranova, Jana; Vinakurau, Stepan; Richter, Jan; Starec, Miroslav; Fiserova, Anna; Rosina, Jozef

    2011-01-01

    Our research compared whole pelvic (WP) and prostate-only (PO) 3-dimensional conformal radiotherapy (3DCRT) techniques in terms of the incidence and evolution of acute and late toxicity of the rectum and urinary bladder, and identified the PTV-parameters influencing these damages and changes in antitumor immune response. We analyzed 197 prostate cancer patients undergoing 3DCRT for gastrointestinal (GI) and genitourinary (GU) toxicities, and conducted a pilot immunological study including flow cytometry and an NK cell cytotoxicity assay. Acute and late toxicities were recorded according to the RTOG and the LENT-SOMA scales, respectively. Univariate and multivariate analyses were conducted for factors associated with toxicity. In the WP group, an increase of acute rectal toxicity was observed. A higher incidence of late GI/GU toxicity appeared in the PO group. Only 18 patients (WP-7.76% and PO-11.11%) suffered severe late GI toxicity, and 26 patients (WP-11.21% and PO-16.05%) severe late GU toxicity. In the majority of acute toxicity suffering patients, the diminution of late GI/GU toxicity to grade 1 or to no toxicity after radiotherapy was observed. The 3DCRT technique itself, patient age, T stage of TNM classification, surgical intervention, and some dose-volume parameters emerged as important factors in the probability of developing acute and late GI/GU toxicity. The proportion and differentiation of NK cells positively correlated during 3DCRT and negatively so after its completion with dose-volumes of the rectum and urinary bladder. T and NKT cells were down-regulated throughout the whole period. We found a negative correlation between leukocyte numbers and bone marrow irradiated by 44-54 Gy and a positive one for NK cell proportion and doses of 5-25 Gy. The acute GU, late GU, and GI toxicities up-regulated the T cell (CTL) numbers and NK cytotoxicity. Our study demonstrates the association of acute and late damage of the urinary bladder and rectum, with

  16. Technological advances in radiotherapy of rectal cancer: opportunities and challenges.

    Science.gov (United States)

    Appelt, Ane L; Sebag-Montefiore, David

    2016-07-01

    This review summarizes the available evidence for the use of modern radiotherapy techniques for chemoradiotherapy for rectal cancer, with specific focus on intensity-modulated radiotherapy (IMRT) and volumetric arc therapy (VMAT) techniques. The dosimetric benefits of IMRT and VMAT are well established, but prospective clinical studies are limited, with phase I-II studies only. Recent years have seen the publication of a few larger prospective patient series as well as some retrospective cohorts, several of which include much needed late toxicity data. Overall results are encouraging, as toxicity levels - although varying across reports - appear lower than for 3D conformal radiotherapy. Innovative treatment techniques and strategies which may be facilitated by the use of IMRT/VMAT include simultaneously integrated tumour boost, adaptive treatment, selective sparing of specific organs to enable chemotherapy escalation, and nonsurgical management. Few prospective studies of IMRT and VMAT exist, which causes uncertainty not just in regards to the clinical benefit of these technologies but also in the optimal use. The priority for future research should be subgroups of patients who might receive relatively greater benefit from innovative treatment techniques, such as patients receiving chemoradiotherapy with definitive intent and patients treated with dose escalation.

  17. Modern plasmonics

    CERN Document Server

    Maradudin, Alexei A; Barnes, William L

    2014-01-01

    Plasmonics is entering the curriculum of many universities, either as a stand alone subject, or as part of some course or courses. Nanotechnology institutes have been, and are being, established in universities, in which plasmonics is a significant topic of research. Modern Plasmonics book offers a comprehensive presentation of the properties of surface plasmon polaritons, in systems of different structures and various natures, e.g. active, nonlinear, graded, theoretical/computational and experimental techniques for studying them, and their use in a variety of applications. Contains materia

  18. Modern spectroscopy

    CERN Document Server

    Hollas, J Michael

    2013-01-01

    The latest edition of this highly acclaimed title introduces the reader to a wide range of spectroscopies, and includes both the background theory and applications to structure determination and chemical analysis.  It covers rotational, vibrational, electronic, photoelectron and Auger spectroscopy, as well as EXAFs and the theory of lasers and laser spectroscopy. A  revised and updated edition of a successful, clearly written book Includes the latest developments in modern laser techniques, such as cavity ring-down spectroscopy and femtosecond lasers Provides numerous worked examples, calculations and questions at the end of chapters.

  19. Changes in Pulmonary Function After Three-Dimensional Conformal Radiotherapy, Intensity-Modulated Radiotherapy, or Proton Beam Therapy for Non-Small-Cell Lung Cancer

    International Nuclear Information System (INIS)

    Lopez Guerra, Jose L.; Gomez, Daniel R.; Zhuang Yan; Levy, Lawrence B.; Eapen, George; Liu, Hongmei; Mohan, Radhe; Komaki, Ritsuko; Cox, James D.; Liao Zhongxing

    2012-01-01

    Purpose: To investigate the extent of change in pulmonary function over time after definitive radiotherapy for non-small-cell lung cancer (NSCLC) with modern techniques and to identify predictors of changes in pulmonary function according to patient, tumor, and treatment characteristics. Patients and Methods: We analyzed 250 patients who had received ≥60 Gy radio(chemo)therapy for primary NSCLC in 1998–2010 and had undergone pulmonary function tests before and within 1 year after treatment. Ninety-three patients were treated with three-dimensional conformal radiotherapy, 97 with intensity-modulated radiotherapy, and 60 with proton beam therapy. Postradiation pulmonary function test values were evaluated among individual patients compared with the same patient’s preradiation value at the following time intervals: 0–4 (T1), 5–8 (T2), and 9–12 (T3) months. Results: Lung diffusing capacity for carbon monoxide (DLCO) was reduced in the majority of patients along the three time periods after radiation, whereas the forced expiratory volume in 1 s per unit of vital capacity (FEV1/VC) showed an increase and decrease after radiation in a similar percentage of patients. There were baseline differences (stage, radiotherapy dose, concurrent chemotherapy) among the radiation technology groups. On multivariate analysis, the following features were associated with larger posttreatment declines in DLCO: pretreatment DLCO, gross tumor volume, lung and heart dosimetric data, and total radiation dose. Only pretreatment DLCO was associated with larger posttreatment declines in FEV1/VC. Conclusions: Lung diffusing capacity for carbon monoxide is reduced in the majority of patients after radiotherapy with modern techniques. Multiple factors, including gross tumor volume, preradiation lung function, and dosimetric parameters, are associated with the DLCO decline. Prospective studies are needed to better understand whether new radiation technology, such as proton beam therapy

  20. Radiotherapy dosimetry audit: three decades of improving standards and accuracy in UK clinical practice and trials.

    Science.gov (United States)

    Clark, Catharine H; Aird, Edwin G A; Bolton, Steve; Miles, Elizabeth A; Nisbet, Andrew; Snaith, Julia A D; Thomas, Russell A S; Venables, Karen; Thwaites, David I

    2015-01-01

    Dosimetry audit plays an important role in the development and safety of radiotherapy. National and large scale audits are able to set, maintain and improve standards, as well as having the potential to identify issues which may cause harm to patients. They can support implementation of complex techniques and can facilitate awareness and understanding of any issues which may exist by benchmarking centres with similar equipment. This review examines the development of dosimetry audit in the UK over the past 30 years, including the involvement of the UK in international audits. A summary of audit results is given, with an overview of methodologies employed and lessons learnt. Recent and forthcoming more complex audits are considered, with a focus on future needs including the arrival of proton therapy in the UK and other advanced techniques such as four-dimensional radiotherapy delivery and verification, stereotactic radiotherapy and MR linear accelerators. The work of the main quality assurance and auditing bodies is discussed, including how they are working together to streamline audit and to ensure that all radiotherapy centres are involved. Undertaking regular external audit motivates centres to modernize and develop techniques and provides assurance, not only that radiotherapy is planned and delivered accurately but also that the patient dose delivered is as prescribed.

  1. Radiotherapy dosimetry audit: three decades of improving standards and accuracy in UK clinical practice and trials

    Science.gov (United States)

    Aird, Edwin GA; Bolton, Steve; Miles, Elizabeth A; Nisbet, Andrew; Snaith, Julia AD; Thomas, Russell AS; Venables, Karen; Thwaites, David I

    2015-01-01

    Dosimetry audit plays an important role in the development and safety of radiotherapy. National and large scale audits are able to set, maintain and improve standards, as well as having the potential to identify issues which may cause harm to patients. They can support implementation of complex techniques and can facilitate awareness and understanding of any issues which may exist by benchmarking centres with similar equipment. This review examines the development of dosimetry audit in the UK over the past 30 years, including the involvement of the UK in international audits. A summary of audit results is given, with an overview of methodologies employed and lessons learnt. Recent and forthcoming more complex audits are considered, with a focus on future needs including the arrival of proton therapy in the UK and other advanced techniques such as four-dimensional radiotherapy delivery and verification, stereotactic radiotherapy and MR linear accelerators. The work of the main quality assurance and auditing bodies is discussed, including how they are working together to streamline audit and to ensure that all radiotherapy centres are involved. Undertaking regular external audit motivates centres to modernize and develop techniques and provides assurance, not only that radiotherapy is planned and delivered accurately but also that the patient dose delivered is as prescribed. PMID:26329469

  2. Cone beam computed tomography: An accurate imaging technique in comparison with orthogonal portal imaging in intensity-modulated radiotherapy for prostate cancer

    Directory of Open Access Journals (Sweden)

    Om Prakash Gurjar

    2016-03-01

    Full Text Available Purpose: Various factors cause geometric uncertainties during prostate radiotherapy, including interfractional and intrafractional patient motions, organ motion, and daily setup errors. This may lead to increased normal tissue complications when a high dose to the prostate is administered. More-accurate treatment delivery is possible with daily imaging and localization of the prostate. This study aims to measure the shift of the prostate by using kilovoltage (kV cone beam computed tomography (CBCT after position verification by kV orthogonal portal imaging (OPI.Methods: Position verification in 10 patients with prostate cancer was performed by using OPI followed by CBCT before treatment delivery in 25 sessions per patient. In each session, OPI was performed by using an on-board imaging (OBI system and pelvic bone-to-pelvic bone matching was performed. After applying the noted shift by using OPI, CBCT was performed by using the OBI system and prostate-to-prostate matching was performed. The isocenter shifts along all three translational directions in both techniques were combined into a three-dimensional (3-D iso-displacement vector (IDV.Results: The mean (SD IDV (in centimeters calculated during the 250 imaging sessions was 0.931 (0.598, median 0.825 for OPI and 0.515 (336, median 0.43 for CBCT, p-value was less than 0.0001 which shows extremely statistical significant difference.Conclusion: Even after bone-to-bone matching by using OPI, a significant shift in prostate was observed on CBCT. This study concludes that imaging with CBCT provides a more accurate prostate localization than the OPI technique. Hence, CBCT should be chosen as the preferred imaging technique.

  3. Dosimetric comparison of deep inspiration breath hold and free breathing technique in stereotactic body radiotherapy for localized lung tumor using Flattening Filter Free beam

    Science.gov (United States)

    Mani, Karthick Raj; Bhuiyan, Md. Anisuzzaman; Alam, Md. Mahbub; Ahmed, Sharif; Sumon, Mostafa Aziz; Sengupta, Ashim Kumar; Rahman, Md. Shakilur; Azharul Islam, Md. S. M.

    2018-03-01

    Aim: To compare the dosimetric advantage of stereotactic body radiotherapy (SBRT) for localized lung tumor between deep inspiration breath hold technique and free breathing technique. Materials and methods: We retrospectively included ten previously treated lung tumor patients in this dosimetric study. All the ten patients underwent CT simulation using 4D-CT free breathing (FB) and deep inspiration breath hold (DIBH) techniques. Plans were created using three coplanar full modulated arc using 6 MV flattening filter free (FFF) bream with a dose rate of 1400 MU/min. Same dose constraints for the target and the critical structures for a particular patient were used during the plan optimization process in DIBH and FB datasets. We intend to deliver 50 Gy in 5 fractions for all the patients. For standardization, all the plans were normalized at target mean of the planning target volume (PTV). Doses to the critical structures and targets were recorded from the dose volume histogram for evaluation. Results: The mean right and left lung volumes were inflated by 1.55 and 1.60 times in DIBH scans compared to the FB scans. The mean internal target volume (ITV) increased in the FB datasets by 1.45 times compared to the DIBH data sets. The mean dose followed by standard deviation (x¯ ± σx¯) of ipsilateral lung for DIBH-SBRT and FB-SBRT plans were 7.48 ± 3.57 (Gy) and 10.23 ± 4.58 (Gy) respectively, with a mean reduction of 36.84% in DIBH-SBRT plans. Ipsilateral lung were reduced to 36.84% in DIBH plans compared to FB plans. Conclusion: Significant dose reduction in ipsilateral lung due to the lung inflation and target motion restriction in DIBH-SBRT plans were observed compare to FB-SBRT. DIBH-SBRT plans demonstrate superior dose reduction to the normal tissues and other critical structures.

  4. Clinical Applications of 3-D Conformal Radiotherapy

    Science.gov (United States)

    Miralbell, Raymond

    Although a significant improvement in cancer cure (i.e. 20% increment) has been obtained in the last 2-3 decades, 30-40% of patients still fail locally after curative radiotherapy. In order to improve local tumor control rates with radiotherapy high doses to the tumor volume are frequently necessary. Three-dimensional conformal radiation therapy (3-D CRT) is used to denote a spectrum of radiation planning and delivery techniques that rely on three-dimensional imaging to define the target (tumor) and to distinguish it from normal tissues. Modern, high-precision radiotherapy (RT) techniques are needed in order to implement the goal of optimal tumor destruction delivering minimal dose to the non-target normal tissues. A better target definition is nowadays possible with contemporary imaging (computerized tomography, magnetic resonance imaging, and positron emission tomography) and image registration technology. A highly precise dose distributions can be obtained with optimal 3-D CRT treatment delivery techniques such as stereotactic RT, intensity modulated RT (IMRT), or protontherapy (the latter allowing for in-depth conformation). Patient daily set-up repositioning and internal organ immobilization systems are necessary before considering to undertake any of the above mentioned high-precision treatment approaches. Prostate cancer, brain tumors, and base of skull malignancies are among the sites most benefitting of dose escalation approaches. Nevertheless, a significant dose reduction to the normal tissues in the vicinity of the irradiated tumor also achievable with optimal 3-D CRT may also be a major issue in the treatment of pediatric tumors in order to preserve growth, normal development, and to reduce the risk of developing radiation induced diseases such as cancer or endocrinologic disorders.

  5. ‘Inverted Y’ field radiotherapy planning with multi-leaf collimator: A single isocentric technique using multiple fields

    Directory of Open Access Journals (Sweden)

    Puja Sahai

    2015-01-01

    Full Text Available The purpose of our study is to describe a planning technique using multi-leaf collimator and asymmetric fields for irradiating an ‘inverted Y’ shaped geometry in a patient with testicular seminoma. The entire target area covering the para-aortic, pelvic, and inguinal nodal regions was split into three fields. Single isocenter half-beam block technique was employed. The fields were planned with antero-posterior and postero-anterior portals with a differential weightage. The dose was prescribed at the respective reference points of the fields. A uniform dose distribution for the entire portal was achieved without any under- or over-dosing at the field junctions.  

  6. Radiotherapy of pineal tumors

    International Nuclear Information System (INIS)

    Danoff, B.; Sheline, G.E.

    1984-01-01

    Radiotherapy has universally been used in the treatment of pineal tumors and suprasellar germinomas. Recently however, major technical advances related to the use of the operating microscope and development of microsurgical techniques have prompted a renewed interest in the direct surgical approach for biopsy and/or excision. This interest has resulted in a controversy regarding the role of surgery prior to radiotherapy. Because of the heterogeneity of tumors occurring in the pineal region (i.e., germ cell tumors, pineal parenchymal tumors, glial tumors, and cysts) and their differing biological behavior, controversy also surrounds aspects of radiotherapy such as: the optimal radiation dose, the volume to be irradiated, and indications for prophylactic spinal irradiation. A review of the available data is presented in an attempt to answer these questions

  7. Response assessment after induction chemotherapy for head and neck squamous cell carcinoma : From physical examination to modern imaging techniques and beyond

    NARCIS (Netherlands)

    de Bree, Remco; Wolf, Gregory T; de Keizer, Bart; Nixon, Iain J; Hartl, Dana M; Forastiere, Arlene A; Haigentz, Missak; Rinaldo, Alessandra; Rodrigo, Juan P.; Saba, Nabil F; Suárez, Carlos; Vermorken, Jan B; Ferlito, Alfio

    2017-01-01

    Significant correlations between the response to induction chemotherapy and success of subsequent radiotherapy have been reported and suggest that the response to induction chemotherapy is able to predict a response to radiotherapy. Therefore, induction chemotherapy may be used to tailor the

  8. Modeling the Risk of Secondary Malignancies after Radiotherapy

    Directory of Open Access Journals (Sweden)

    Uwe Schneider

    2011-11-01

    Full Text Available In developed countries, more than half of all cancer patients receive radiotherapy at some stage in the management of their disease. However, a radiation-induced secondary malignancy can be the price of success if the primary cancer is cured or at least controlled. Therefore, there is increasing concern regarding radiation-related second cancer risks in long-term radiotherapy survivors and a corresponding need to be able to predict cancer risks at high radiation doses. Of particular interest are second cancer risk estimates for new radiation treatment modalities such as intensity modulated radiotherapy, intensity modulated arc-therapy, proton and heavy ion radiotherapy. The long term risks from such modern radiotherapy treatment techniques have not yet been determined and are unlikely to become apparent for many years, due to the long latency time for solid tumor induction. Most information on the dose-response of radiation-induced cancer is derived from data on the A-bomb survivors who were exposed to γ-rays and neutrons. Since, for radiation protection purposes, the dose span of main interest is between zero and one Gy, the analysis of the A-bomb survivors is usually focused on this range. With increasing cure rates, estimates of cancer risk for doses larger than one Gy are becoming more important for radiotherapy patients. Therefore in this review, emphasis was placed on doses relevant for radiotherapy with respect to radiation induced solid cancer. Simple radiation protection models should be used only with extreme care for risk estimates in radiotherapy, since they are developed exclusively for low dose. When applied to scatter radiation, such models can predict only a fraction of observed second malignancies. Better semi-empirical models include the effect of dose fractionation and represent the dose-response relationships more accurately. The involved uncertainties are still huge for most of the organs and tissues. A major reason for

  9. Tangential Volumetric Modulated Radiotherapy - A New Technique for Large Scalp Lesions with a Case Study in Lentigo Maligna

    Directory of Open Access Journals (Sweden)

    E. Daniel Santos

    2015-06-01

    Full Text Available Introduction: Dose homogeneity within and dose conformity to the target volume can be a challenge to achieve when treating large area scalp lesions. Traditionally High Dose Rate (HDR brachytherapy (BT scalp moulds have been considered the ultimate conformal therapy. We have developed a new technique, Tangential Volumetric Modulated Arc Therapy (TVMAT that treats with the beam tangential to the surface of the scalp. In the TVMAT plan the collimating jaws protect dose-sensitive tissue in close proximity to the planning target volume (PTV. Not all the PTV is within the beam aperture as defined by the jaws during all the beam-on time. We report the successful treatment of one patient. Methods: A patient with biopsy proven extensive lentigo maligna on the scalp was simulated and three plans were created; one using a HDR brachytherapy surface mould, another using a conventional VMAT technique and a third using our new TVMAT technique. The patient was prescribed 55 Gy in 25 fractions. Plans were optimised so that PTV V100% = 100%. Plans were compared using Dose-Value Histogram (DVH analysis, and homogeneity and conformity indices. Results: BT, VMAT and TVMAT PTV median coverage was 105.51%, 103.46% and 103.62%, with homogeneity index of 0.33, 0.07 and 0.07 and the conformity index of 0.30, 0.69 and 0.83 respectively. The median dose to the left hippocampus was 11.8 Gy, 9.0 Gy and 0.6 Gy and the median dose to the right hippocampus was 12.6 Gy, 9.4 Gy and 0.7 Gy for the BT, VMAT and TVMAT respectively. Overall TVMAT delivered the least doses to the surrounding organs, BT delivered the highest. Conclusions: TVMAT was superior to VMAT which was in turn superior to BT in PTV coverage, conformity and homogeneity and delivery of dose to the surrounding organs at risk. The patient was successfully treated to full dose with TVMAT. TVMAT was verified as being the best amongst the three techniques in a second patient.

  10. Establishing stereotactic body radiotherapy with flattening filter free techniques in the treatment of pulmonary lesions - initial experiences from a single institution

    International Nuclear Information System (INIS)

    Rieber, Juliane; Tonndorf-Martini, Eric; Schramm, Oliver; Rhein, Bernhard; König, Laila; Adeberg, Sebastian; Meyerhof, Eva; Mohr, Angela; Kappes, Jutta; Hoffmann, Hans; Debus, Jürgen; Rieken, Stefan

    2016-01-01

    Stereotactic body radiotherapy (SBRT) using flattening filter free (FFF)-techniques has been increasingly applied during the last years. However, clinical studies investigating this emerging technique are still rare. Hence, we analyzed toxicity and clinical outcome of pulmonary SBRT with FFF-techniques and performed dosimetric comparison to conventional techniques using flattening filters (FF). Between 05/2014 and 06/2015, 56 consecutive patients with 61 pulmonary lesions were treated with SBRT in FFF-mode. Central lesions received 8 × 7.5 Gy delivered to the conformally enclosing 80 %-isodose, while peripheral lesions were treated with 3 × 15 Gy, prescribed to the 65 %-isodose. Early and late toxicity (after 6 months) as well as initial clinical outcomes were evaluated. Furthermore, [deleted] plan quality and efficiency were evaluated by analyzing conformity, beam- on and total treatment delivery times in comparison to plans with FF-dose application. Median follow-up time was 9.3 months (range 1.5–18.0 months). Early toxicity was low with only 5 patients (8.9 %) reporting CTCAE 2° or higher side-effects. Only one patient (1.8 %) was diagnosed with radiation-induced pneumonitis CTCAE 3°, while 2 (3.6 %) patients suffered from pneumonitis CTCAE 2°. After 6 months, no toxicity greater than CTCAE 2° was reported. 1-year local progression-free survival, distant progression-free survival and overall survival were 92.8 %, 78.0 %, and 94.4 %, respectively. While plan quality was similar for FFF- and FF-plans in respect to conformity (p = 0.275), median beam-on time as well as total treatment time were significantly reduced for SBRT in FFF-mode compared to FF-mode (p ≤ 0.001, p ≤ 0.001). Patient treatment with SBRT using FFF-techniques is safe and provides promising clinical results with only modest toxicity at significantly increased dose delivery speed

  11. Modernity after Modernity

    Directory of Open Access Journals (Sweden)

    Marin Dinu

    2007-08-01

    Full Text Available A strategy for the second modernization raises, beyond objectives, a series of epistemicresponsibilities. It is known that modernization stemming from the Enlightment had, among other things,the pretense that it is a project which is self-legitimating. Its profound rationales are the only justification.Referential self-centering proved to be the one that made possible a practice of the new. Modernizationhaving the function of renouncing myth – meaning an eliminatory formula for the past – and thefixation in the opportunity and potentiality of the present, seemed to close an insoluble but extremelyengrossing problem: that of a propensity towards utopia, of the risky escape towards the future. Thetraditionalization of the new constitutes a support for the daring to break out of the captivity of themoment.Modernization becomes the experience of combining the new which, thus, creates a succession ofpresent times. The future is no longer the result of fantasy, but a system’s direct expression to combine thenew. Therefore the future is an option for one or another model of the present, often tested previouslysomewhere else. In a non-metaphysical way, the future can be seen, touched, tried, lived by simplegeographical movement. The sense of evolution has de-temporalized taking the form of the concomitant,parallel, enclosed, neighboring space. We just have to be in the trend, to evolve in the context.Globalization defines the context and its conception – as a project of the second modernity – showsus the trends. The problem is how to understand the context in order to find the sense of the trend. Are wethe load the sense with the values of the first modernity or will we have to turn to the values of anothermodernity? Why do we have to move away from the significance of the processes which made up the firstmodernity? How do we relate to the content of the new context in which the structural trends of today’sworld are taking place? What is the

  12. Role of Radiotherapy in Metastatic Non-small Cell Lung Cancer (NSCLC

    Directory of Open Access Journals (Sweden)

    Sergio L. Faria

    2014-10-01

    Full Text Available Radiotherapy has had important role in the palliation of NSCLC. Randomized trials tend to suggest that, in general, short regimens give similar palliation and toxicity compared to longer regimens. The benefit of combining chemotherapy to radiosensitize the palliative radiation treatment is an open question, but so far it has not been proved to be very useful in NSCLC. The addition of molecular targeted drugs to radiotherapy outside of approved regimens or clinical trials warrants careful consideration for every single case and probably should not be used as a routine management.Stereotactic radiosurgery (SRS and stereotactic body radiation therapy (SBRT are modern techniques being used each time more frequently in the treatment of single or oligometastases. In general, they offer good tumour control with little toxicity (with a more expensive cost compared to the traditionally fractionated radiotherapy regimens.

  13. Influence of conformal radiotherapy technique on survival after chemoradiotherapy for patients with stage III non-small cell lung cancer in the National Cancer Data Base.

    Science.gov (United States)

    Sher, David J; Koshy, Matthew; Liptay, Michael J; Fidler, Mary Jo

    2014-07-01

    Definitive chemoradiotherapy is a core treatment modality for patients with stage III non-small cell lung cancer (NSCLC). Although radiotherapy (RT) technologies have advanced dramatically, to the authors' knowledge relatively little is known regarding the importance of irradiation technique on outcome, particularly given the competing risk of distant metastasis. The National Cancer Data Base was used to determine predictors of overall survival (OS) in patients with AJCC stage III NSCLC who were treated with chemoradiotherapy, focusing on the importance of conformal RT (CRT). Patients with stage III NSCLC who were treated with chemoradiotherapy between 2003 and 2005 in the National Cancer Data Base were included. RT technique was defined as conventional, 3-dimensional-conformal, or intensity-modulated RT (IMRT), the latter 2 combined as CRT. Cox proportional hazards regression was performed for univariable and multivariable analyses of OS. The median, 3-year, and 5-year survival outcomes for the 13,292 patients were 12.9 months, 19%, and 11%, respectively. The 3-year and 5-year survival probabilities of patients receiving CRT versus no CRT were 22% versus 19% and 14% versus 11%, respectively (P < .0001). On multivariable analysis, CRT was found to be significantly associated with improved OS (hazards ratio, 0.89). This effect was confirmed on sensitivity analyses, including restricting the cohort to minimum 6-month survivors, young patients with stage IIIA disease, and propensity score-matching. Institutional academic status and patient volume were not found to be associated with OS. CRT was found to be independently associated with a survival advantage. These results reflect the importance of optimal locoregional therapy in patients with stage III NSCLC and provide motivation for further study of advanced RT technologies in patients with NSCLC. © 2014 American Cancer Society.

  14. Lateral high abdominal ovariopexy: an original surgical technique for protection of the ovaries during curative radiotherapy for Hodgkin's disease

    International Nuclear Information System (INIS)

    Gaetini, A.; De Simone, M.; Urgesi, A.; Levis, A.; Resegotti, A.; Ragona, R.; Anglesio, S.

    1988-01-01

    An original surgical method for gonadal protection in young women given pelvic radiation for Hodgkin's disease is presented. Lateral high ovarian transposition (LHAO) consists of the transposition of the ovaries into the paracolic gutter during staging laparotomy, after disconnecting the gonads from the fallopian tubes by dividing the tubo-ovarian vessels. The technique's effectiveness was assessed by a study using clinical investigation, radioimmunoassay (RIA) determination of sex hormones, and dosimetry; of 18 patients treated, 10 participated in the study. All but one have normal menses and hormone values, and one pregnancy occurred. We also calculated the doses absorbed by the ovaries and proved that, during inverted Y irradiation following LHAO, the ovaries are exposed to nearly one-half the dose they receive after traditional medial transposition. During subtotal nodal irradiation after LHAO, the irradiation dose is higher than after medialisation, but absolute values are minimal and castration is not induced

  15. Modern teaching for modern education

    OpenAIRE

    Mirascieva, Snezana

    2016-01-01

    Carrying the epithet of being contemporary education today means modern teaching. If modern education is a state in the field of education of all its elements, then teaching will also be a state with its own special features defining it as modern. The main issues of concern in this paper relate to what constitutes modern teaching, which features determine it as being modern, and how much is teaching today following the trend of modernization.

  16. Advantages and disadvantages of using non-coplanar techniques in radiotherapy of the abdomen formed 3D; Ventajas e inconvenientes del uso de tecnicas con coplanares en radiaoterpia 3D conformada de abdomen

    Energy Technology Data Exchange (ETDEWEB)

    Urena Llinares, A.; Castro Ramirez, I.; Iborra Oquendo, M. A; Quinones Rodriguez, L. A.; Angulo Pain, E.

    2011-07-01

    3D Radiotherapy locations abdomen, especially in pancreas and stomach cancers is often extremely difficult if we are to meet the dose constraints to organs at risk due to proximity and many of these (liver, kidneys, intestines, lungs, bone. ..). Of these, the most critical are the kidneys, which also present values of tolerance, in most cases difficult to meet. This is done in our hospital are using non-coplanar techniques performing well both as coating PTV dose to both kidneys.

  17. Experimental study of movements respiratory conditions acceptable in radiotherapy techniques advanced; Estudio experimental de las condiciones de movimiento respiratorio aceptables en tecnicas de radioterapia avanzada

    Energy Technology Data Exchange (ETDEWEB)

    Carrasco de Fez, P.; Ruiz Martinez, A.; Ruiz Martinez, A.; Jornet Sala, N.; Latorre Musoll, A.; Eudaldo Puell, T.; Ribas Morales, M.

    2015-07-01

    The aim is Determine experimentally in what conditions the movement of the PTV produces uncertainties unacceptable in the various stages of the treatment radiotherapy, from the acquisition of imagens 4D to the irradiation. (Author)

  18. SU-C-BRD-05: Implementation of Incident Learning in the Safety and Quality Management of Radiotherapy: The Primary Experience in a New Established Program with Advanced Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Yang, R; Wang, J [Peking University Third Hospital, Beijing, Beijing (China)

    2014-06-15

    Purpose: To explore the implementation and effectiveness of incident learning for the safety and quality of radiotherapy in a new established radiotherapy program with advanced technology. Methods: Reference to the consensus recommendations by American Association of Physicist in Medicine, an incident learning system was specifically designed for reporting, investigating, and learning of individual radiotherapy incidents in a new established radiotherapy program, with 4D CBCT, Ultrasound guided radiotherapy, VMAT, gated treatment delivered on two new installed linacs. The incidents occurring in external beam radiotherapy from February, 2012 to January, 2014 were reported. Results: A total of 33 reports were analyzed, including 28 near misses and 5 incidents. Among them, 5 originated in imaging for planning, 25 in planning, 1 in plan transfer, 1 in commissioning and 1 in treatment delivery. Among them, three near misses originated in the safety barrier of the radiotherapy process. In terms of error type, 1 incident was classified as wrong patient, 7 near misses/incidents as wrong site, 6 as wrong laterality, 5 as wrong dose, 7 as wrong prescription, and 7 as suboptimal plan quality. 5 incidents were all classified as grade 1/2 of dosimetric severity, 1 as grade 0, and the other 4 as grade 1 of medical severity. For the causes/contributory factors, negligence, policy not followed, inadequate training, failure to develop an effective plan, and communication contributed to 19, 15, 12, 5 and 3 near misses/incidents, respectively. The average incident rate per 100 patients treated was 0.4; this rate fell to 0.28% in the second year from 0.56% in the first year. The rate of near miss fell to 1.24% from 2.22%. Conclusion: Effective incident learning can reduce the occurrence of near miss/incidents, enhance the culture of safety. Incident learning is an effective proactive method for improving the quality and safety of radiotherapy.

  19. Influence of boost technique (external beam radiotherapy or brachytherapy) on the outcome of patients with carcinoma of the base of the tongue

    International Nuclear Information System (INIS)

    Regueiro, C.A.; Millan, I.; Torre, A. de la; Valcarcel, F.J.; Magallon, R.; Fernandez, E.; Aragon, G.

    1995-01-01

    We reviewed 90 patients with squamous cell carcinoma of the base of the tongue. Fifty-three patients were treated with external beam radiotherapy alone (3 T1, 11 T2, 21 T3, and 18 T4 tumors) and thirty-seven patients were treated with external beam radiotherapy plus brachytherapy boost (4 T1, 15 T2, 11 T3, and 7 T4 tumors). For patients with T1, T2 and T3 primaries, the actuarial 3-year local relapse-free survival was 42% following external beam radiotherapy alone and 67% following external beam radiotherapy plus brachytherapy (p<0.05). The actuarial 3-year cause specific survival for these T-stages was 37% for patients treated with external beam radiotherapy alone and 53% for patients treated with external beam radiotherapy plus brachytherapy (p=0.1). In the Cox multivariate analyses restricted patients with T1, T2 and T3 staged tumors, treatment modality was the only predictor for local control but no influence on specific survival was found. The trend towards significant differences in specific survival found in the univariate comparison of both treatment modalities was probably due to the significantly higher number of N-positive patients treated with external beam radiotherapy alone. When all stages were included in the Cox analysis, low hemoglobin level, invasion of deep muscle, number of palpable nodes, and history of weight loss significantly influenced the outcome. Soft tissue necrosis occurred more frequently in patients treated with external beam radiotherapy plus brachytherapy (33% vs. 10%, p=0.52). (orig.)

  20. SU-C-BRD-05: Implementation of Incident Learning in the Safety and Quality Management of Radiotherapy: The Primary Experience in a New Established Program with Advanced Techniques

    International Nuclear Information System (INIS)

    Yang, R; Wang, J

    2014-01-01

    Purpose: To explore the implementation and effectiveness of incident learning for the safety and quality of radiotherapy in a new established radiotherapy program with advanced technology. Methods: Reference to the consensus recommendations by American Association of Physicist in Medicine, an incident learning system was specifically designed for reporting, investigating, and learning of individual radiotherapy incidents in a new established radiotherapy program, with 4D CBCT, Ultrasound guided radiotherapy, VMAT, gated treatment delivered on two new installed linacs. The incidents occurring in external beam radiotherapy from February, 2012 to January, 2014 were reported. Results: A total of 33 reports were analyzed, including 28 near misses and 5 incidents. Among them, 5 originated in imaging for planning, 25 in planning, 1 in plan transfer, 1 in commissioning and 1 in treatment delivery. Among them, three near misses originated in the safety barrier of the radiotherapy process. In terms of error type, 1 incident was classified as wrong patient, 7 near misses/incidents as wrong site, 6 as wrong laterality, 5 as wrong dose, 7 as wrong prescription, and 7 as suboptimal plan quality. 5 incidents were all classified as grade 1/2 of dosimetric severity, 1 as grade 0, and the other 4 as grade 1 of medical severity. For the causes/contributory factors, negligence, policy not followed, inadequate training, failure to develop an effective plan, and communication contributed to 19, 15, 12, 5 and 3 near misses/incidents, respectively. The average incident rate per 100 patients treated was 0.4; this rate fell to 0.28% in the second year from 0.56% in the first year. The rate of near miss fell to 1.24% from 2.22%. Conclusion: Effective incident learning can reduce the occurrence of near miss/incidents, enhance the culture of safety. Incident learning is an effective proactive method for improving the quality and safety of radiotherapy

  1. Radioactivity helps out in Medicine. Radiotherapy

    International Nuclear Information System (INIS)

    Douis, Michel; Olombel, Andre

    1978-01-01

    Some notions on the action of radiations on tissues are followed by a review of the different radiotherapic techniques: metabolic radiotherapy, curietherapy, transcutaneous radiotherapy. The radioelements used in these various techniques are then described, together with the way in which they are conditioned (colloids, applicators, sources) [fr

  2. Testing the assessment of new radiation oncology technology and treatments framework using the evaluation of post-prostatectomy radiotherapy techniques

    International Nuclear Information System (INIS)

    Duchesne, Gillian M.; Haworth, Annette; Hornby, Colin; Bone, Eric; Carter, Hannah; Martin, Andrew; Ebert, Martin A.; Gagliardi, Frank; Gibbs, Adrian; Sidhom, Mark; Wood, Maree; Jackson, Michael

    2016-01-01

    We tested the ability of the Assessment of New Radiation Oncology Technology and Treatments framework to determine the clinical efficacy and safety of intensity-modulated radiation therapy (IMRT) compared with 3-dimensional radiation therapy (3DCRT) for post-prostatectomy radiation therapy (PPRT) to support its timely health economic evaluation. Treatment plans produced using FROGG guidelines provided dosimetry parameters for both techniques at 64 Gy and 70 Gy and were also used to model early and late outcome probabilities. Clinical parameters were derived from early toxicity and quality of life patient data, systematic literature review and expert opinion. Dosimetry parameters were correlated with the measures of clinical efficacy and safety. Data from two patient cohorts (29 and 27 respectively) were collected within the project timeframe, providing evidence for acute toxicity and quality of life, and dosimetric comparisons. Relative rates of tumour control probability (TCP) and normal tissue control probability (NTCP) modelling were readily derived from the planning exercise and demonstrated advantages in uncomplicated TCP for IMRT over 3DCRT, predominantly due to normal tissue sparing. The safety of IMRT delivery was demonstrated with TCP uncompromised by IMRT protocol violations, which achieved rectal sparing only by reducing minimum target dose and coverage. Sources of desk-top and patient-based evidence were successfully used to demonstrate potential improved clinical efficacy and safety of applying dose escalation using IMRT instead of 3DCRT in PPRT.

  3. Modern techniques for the emissions control in thermal electric stations; Tecnicas modernas para el control de emisiones en centrales termoelectricas

    Energy Technology Data Exchange (ETDEWEB)

    Romo Millares, C. A. [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1995-12-31

    This paper presents the techniques and the control equipment for emissions in thermal stations that have the highest possibilities of being considered in the immediate future in the national energy panorama and the established frame for the environmental normativity. The pollutant compounds subject to revision are the nitrogen and sulfur oxides and unburned particles. [Espanol] Se presentan las tecnicas y equipos de control de emisiones para centrales termoelectricas que tienen mayores posibilidades de ser consideradas en el futuro inmediato dentro del panorama energetico nacional y el marco establecido por la normatividad ambiental. Los compuestos contaminantes sujetos a revision son los oxidos de nitrogeno y azufre y las particulas inquemadas.

  4. Modern techniques for the emissions control in thermal electric stations; Tecnicas modernas para el control de emisiones en centrales termoelectricas

    Energy Technology Data Exchange (ETDEWEB)

    Romo Millares, C A [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    This paper presents the techniques and the control equipment for emissions in thermal stations that have the highest possibilities of being considered in the immediate future in the national energy panorama and the established frame for the environmental normativity. The pollutant compounds subject to revision are the nitrogen and sulfur oxides and unburned particles. [Espanol] Se presentan las tecnicas y equipos de control de emisiones para centrales termoelectricas que tienen mayores posibilidades de ser consideradas en el futuro inmediato dentro del panorama energetico nacional y el marco establecido por la normatividad ambiental. Los compuestos contaminantes sujetos a revision son los oxidos de nitrogeno y azufre y las particulas inquemadas.

  5. Radiotherapy and brachytherapy

    International Nuclear Information System (INIS)

    2007-02-01

    This presentation first defines the radiotherapy and brachytherapy techniques, indicates the used ionizing radiations (electromagnetic and particles), describes the mechanisms and processes of action of ionizing radiations: they can be physical by photon-matter interactions (Compton effect and photoelectric effect) or due to electron-matter interactions (excitation, ionization), physical-chemical by direct or indirect action (DNA damage), cellular (mitotic or apoptotic death), tissue (sane and tumorous tissues and differential effect). It discusses the biological efficiency of these treatments which depends on different parameters: intrinsic radio-sensitivity, time (session fractioning and organisation in time), oxygen, radiation quality, cellular cycle, dose rate, temperature. It presents the different types of radiotherapy: external radiotherapy (general sequence, delineation, dosimetry, protection of critical organs, treatment session, quality control, monitoring consultation) and briefly presents some specific techniques (total body irradiation, total cutaneous electron therapy, pre-operation radiotherapy, radio-surgery, hadron-therapy). It proposes an overview of the main indications for this treatment: brain tumours, upper aero digestive tract tumours, bronchial tumours, oesophagus, stomach and pancreas tumours, breast tumours, cervix cancer, rectum tumour, and so on, and indicates the possible associated treatments. The next part addresses brachytherapy. It presents the principles and comments the differences with radiotherapy. It indicates the used radio-elements (Caesium 137, Iridium 192, Iodine 125), describes the implementation techniques (plastic tubes, use of iodine 125, intracavitary and endo-luminal radiation therapy). It proposes an overview of the different treated tumours (skin, breast, prostates, bronchial, oesophagus, ENT) and indicates possible early and late secondary effects for different organs

  6. Thoracic re-irradiation using stereotactic body radiotherapy (SBRT) techniques as first or second course of treatment

    International Nuclear Information System (INIS)

    Kilburn, Jeremy M.; Kuremsky, Jeffrey G.; Blackstock, A. William; Munley, Michael T.; Kearns, William T.; Hinson, William H.; Lovato, James F.; Miller, Antonius A.; Petty, William J.; Urbanic, James J.

    2014-01-01

    Background and purpose: Management for in-field failures after thoracic radiation is poorly defined. We evaluated SBRT as an initial or second course of treatment re-irradiating in a prior high dose region. Materials and methods: Thirty-three patients were treated with re-irradiation defined by the prior 30 Gy isodose line. Kaplan–Meier estimates were performed for local (LC), regional (RC), distant control (DC), and overall survival (OS). The plans when available were summed to evaluate doses to critical structures. Patient and treatment variables were analyzed on UVA for the impact on control and survival measures. Results: Median follow-up was 17 months. Treatment for sequential courses was as follows: (course1:course2) EBRT:SBRT (24 patients), SBRT:SBRT (7 patients), and SBRT:EBRT (3 patients). Median re-irradiation dose and fractionation was 50 Gy and 10 fractions (fx), with a median of 18 months (6–61) between treatments. Median OS was 21 months and 2 year LC 67%, yet LC for >1 fraction was 88% (p = 0.006 for single vs. multiple). 10 patients suffered chronic grade 2–3 toxicity (6 chest wall pain, 3 dyspnea, 1 esophagitis) and 1 grade 5 toxicity with aorta-esophageal fistula after 54 Gy in 3 fx for a central tumor with an estimated EQD2 to the aorta of 200 Gy. Conclusion: Tumor control can be established with re-irradiation using SBRT techniques for in-field thoracic failures at the cost of manageable toxicity

  7. Adaptive Motion Compensation in Radiotherapy

    CERN Document Server

    Murphy, Martin J

    2011-01-01

    External-beam radiotherapy has long been challenged by the simple fact that patients can (and do) move during the delivery of radiation. Recent advances in imaging and beam delivery technologies have made the solution--adapting delivery to natural movement--a practical reality. Adaptive Motion Compensation in Radiotherapy provides the first detailed treatment of online interventional techniques for motion compensation radiotherapy. This authoritative book discusses: Each of the contributing elements of a motion-adaptive system, including target detection and tracking, beam adaptation, and pati

  8. Development of targeted radiotherapy systems

    International Nuclear Information System (INIS)

    Ferro, Guillermina; Villarreal, Jose E.; Garcia, Laura; Tendilla, Jose I.; Paredes, Lydia; Murphy, Consuelo A.; Pedraza, Martha

    2001-01-01

    Conventional or external beam radiotherapy, has been a viable alternative for cancer treatment. Although this technique is effective, its use is limited if the patient has multiple malignant lesions (metastases). An alternative approach is based on the design of radiopharmaceuticals that, to be administered in the patient, are directed specifically toward the target cell producing a selective radiation delivery. This treatment is known as targeted radiotherapy. We have summarized and discussed some results related to our investigations on the development of targeted radiotherapy systems, including aspects of internal dosimetry

  9. The dosimetric control in radiotherapy

    International Nuclear Information System (INIS)

    Veres, A.

    2009-01-01

    The author first presents the thermoluminescent dosimetry method developed by the Equal-Estro Laboratory to control radiotherapy systems, according to which dosimeters are mailed by the radiotherapy centres to the laboratory, and then analyzed with respect to the level of dose bias. In a second part, he discusses the different techniques used for the dosimetric control of new radiotherapy methods (intensity-modulated radiation therapy, tomo-therapy) for which film dosimetry is applied. He also evokes the development of new phantoms and the development of a method for the dosimetric control of proton beams

  10. Determination and identification of synthetic cannabinoids and their metabolites in different matrices by modern analytical techniques – a review

    Energy Technology Data Exchange (ETDEWEB)

    Znaleziona, Joanna; Ginterová, Pavlína; Petr, Jan [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacký University, 17. Listopadu 12, Olomouc CZ-77146 (Czech Republic); Ondra, Peter; Válka, Ivo [Department of Forensic Medicine and Medical Law Faculty Hospital, Hněvotínská 3, Olomouc CZ-77146 (Czech Republic); Ševčík, Juraj [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacký University, 17. Listopadu 12, Olomouc CZ-77146 (Czech Republic); Chrastina, Jan [Institute of Special Education Studies, Faculty of Education, Palacký University, Žižkovo náměsti 5, Olomouc CZ-77146 (Czech Republic); Maier, Vítězslav, E-mail: vitezslav.maier@upol.cz [Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacký University, 17. Listopadu 12, Olomouc CZ-77146 (Czech Republic)

    2015-05-18

    Highlights: • Synthetic cannabinoids from analytical point of view. • Determination and identification methods of synthetic cannabinoids in different matrices. • Analytical techniques used from thin layer chromatography to high resolution mass spectrometry. • Detailed survey of gas and liquid chromatography methods for synthetic cannabinoids analysis. - Abstract: Synthetic cannabinoids have gained popularity due to their easy accessibility and psychoactive effects. Furthermore, they cannot be detected in urine by routine drug monitoring. The wide range of active ingredients in analyzed matrices hinders the development of a standard analytical method for their determination. Moreover, their possible side effects are not well known which increases the danger. This review is focused on the sample preparation and the determination of synthetic cannabinoids in different matrices (serum, urine, herbal blends, oral fluid, hair) published since 2004. The review includes separation and identification techniques, such as thin layer chromatography, gas and liquid chromatography and capillary electrophoresis, mostly coupled with mass spectrometry. The review also includes results by spectral methods like infrared spectroscopy, nuclear magnetic resonance or direct-injection mass spectrometry.

  11. Determination and identification of synthetic cannabinoids and their metabolites in different matrices by modern analytical techniques – a review

    International Nuclear Information System (INIS)

    Znaleziona, Joanna; Ginterová, Pavlína; Petr, Jan; Ondra, Peter; Válka, Ivo; Ševčík, Juraj; Chrastina, Jan; Maier, Vítězslav

    2015-01-01

    Highlights: • Synthetic cannabinoids from analytical point of view. • Determination and identification methods of synthetic cannabinoids in different matrices. • Analytical techniques used from thin layer chromatography to high resolution mass spectrometry. • Detailed survey of gas and liquid chromatography methods for synthetic cannabinoids analysis. - Abstract: Synthetic cannabinoids have gained popularity due to their easy accessibility and psychoactive effects. Furthermore, they cannot be detected in urine by routine drug monitoring. The wide range of active ingredients in analyzed matrices hinders the development of a standard analytical method for their determination. Moreover, their possible side effects are not well known which increases the danger. This review is focused on the sample preparation and the determination of synthetic cannabinoids in different matrices (serum, urine, herbal blends, oral fluid, hair) published since 2004. The review includes separation and identification techniques, such as thin layer chromatography, gas and liquid chromatography and capillary electrophoresis, mostly coupled with mass spectrometry. The review also includes results by spectral methods like infrared spectroscopy, nuclear magnetic resonance or direct-injection mass spectrometry

  12. Aktuelle Technik der Bruststraffung beim Mann nach Gewichtsverlust [Modern technique in male breast contouring after weight loss

    Directory of Open Access Journals (Sweden)

    Stoff, Alexander

    2013-08-01

    Full Text Available [english] The morbid adiposity and its medical consequences demonstrates a growing problem of our current prosperous society. Due to a significant improvement of bariatric techniques and a reduplication of adipose patients during the 20 century, the number of patients, who present to plastic surgeons with a new degree of suffering, has been growing steadily. Initially, the female patients were in the majority, which has been more balanced nowadays.The male breast is a body region that primarily symbolizes masculinity and strenght. In male patients after massive weight loss, this body region remains as an extremly deflated breast envelope without any sign of possible retraction. The plastic surgeon may choose from different single or combinated ltechniques, which are indicated depending on the local and adjacent tissue characteristics.We are presenting our modified technique of male breast reshaping, referring to the technique of Aly, except for a NAC transposition on a central pedicle. The central pedicle is hereby preserved from resection after tremendous liposuction. This central pedicle technique allows a safe and uncomplicated NAC transposition with significant advantages compared to free NAC-Transposition techniques in terms of aesthetical and functional outcome. [german] Die morbide Adipositas mit ihren Langzeitfolgen ist ein zunehmendes Problem unserer heutigen Wohlstandsgesellschaft. Mit einer Verdoppelung der betroffenen Patienten im Laufe des 20. Jahrhunderts ist gleichzeitig durch rasante Verbesserung der bariatrischen Eingriffe auch die Zahl der Patienten signifikant und stetig gestiegen, die sich nach massiver Gewichtsreduktion nun mit neuem Leidensdruck beim Plastischen Chirurgen vorstellen. Hierbei ist die anfängliche Überzahl der weiblichen Patienten in ein ausgewogenes Verhältnis der betroffenen Geschlechter übergegangen. Die männliche Brust, eine Körperregion, die in erster Linie Männlichkeit und Stärke symbolisiert und

  13. Normal tissue complication probability: Does simultaneous integrated boost intensity-modulated radiotherapy score over other techniques in treatment of prostate adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Jothy Basu K

    2009-01-01

    Full Text Available Aim: The main objective of this study was to analyze the radiobiological effect of different treatment strategies on high-risk prostate adenocarcinoma. Materials and Methods: Ten cases of high-risk prostate adenocarcinoma were selected for this dosimetric study. Four different treatment strategies used for treating prostate cancer were compared. Conventional four-field box technique covering prostate and nodal volumes followed by three-field conformal boost (3D + 3DCRT, four-field box technique followed by intensity-modulated radiotherapy (IMRT boost (3D + IMRT, IMRT followed by IMRT boost (IMRT + IMRT, and simultaneous integrated boost IMRT (SIBIMRT were compared in terms of tumor control probability (TCP and normal tissue complication probability (NTCP. The dose prescription except for SIBIMRT was 45 Gy in 25 fractions for the prostate and nodal volumes in the initial phase and 27 Gy in 15 fractions for the prostate in the boost phase. For SIBIMRT, equivalent doses were calculated using biologically equivalent dose assuming the α/β ratio of 1.5 Gy with a dose prescription of 60.75 Gy for the gross tumor volume (GTV and 45 Gy for the clinical target volume in 25 fractions. IMRT plans were made with 15-MV equispaced seven coplanar fields. NTCP was calculated using the Lyman-Kutcher-Burman (LKB model. Results: An NTCP of 10.7 ± 0.99%, 8.36 ± 0.66%, 6.72 ± 0.85%, and 1.45 ± 0.11% for the bladder and 14.9 ± 0.99%, 14.04 ± 0.66%, 11.38 ± 0.85%, 5.12 ± 0.11% for the rectum was seen with 3D + 3DCRT, 3D + IMRT, IMRT + IMRT, and SIBIMRT respectively. Conclusions: SIBIMRT had the least NTCP over all other strategies with a reduced treatment time (3 weeks less. It should be the technique of choice for dose escalation in prostate carcinoma.

  14. Transitioning from conventional radiotherapy to intensity-modulated radiotherapy for localized prostate cancer. Changing focus from rectal bleeding to detailed quality of life analysis

    International Nuclear Information System (INIS)

    Yamazaki, Hideya; Nakamura, Satoaki; Nishimura, Takuya; Yoshida, Ken; Yoshioka, Yasuo; Koizumi, Masahiko; Ogawa, Kazuhiko

    2014-01-01

    With the advent of modern radiation techniques, we have been able to deliver a higher prescribed radiotherapy dose for localized prostate cancer without severe adverse reactions. We reviewed and analyzed the change of toxicity profiles of external beam radiation therapy (EBRT) from the literature. Late rectal bleeding is the main adverse effect, and an incidence of >20% of Grade ≥2 adverse events was reported for 2D conventional radiotherapy of up to 70 Gy. 3D conformal radiation therapy (3D-CRT) was found to reduce the incidence to ∼10%. Furthermore, intensity-modulated radiation therapy (IMRT) reduced it further to a few percentage points. However, simultaneously, urological toxicities were enhanced by dose escalation using highly precise external radiotherapy. We should pay more attention to detailed quality of life (QOL) analysis, not only with respect to rectal bleeding but also other specific symptoms (such as urinary incontinence and impotence), for two reasons: (1) because of the increasing number of patients aged >80 years, and (2) because of improved survival with elevated doses of radiotherapy and/or hormonal therapy; age is an important prognostic factor not only for prostate-specific antigen (PSA) control but also for adverse reactions. Those factors shift the main focus of treatment purpose from survival and avoidance of PSA failure to maintaining good QOL, particularly in older patients. In conclusion, the focus of toxicity analysis after radiotherapy for prostate cancer patients is changing from rectal bleeding to total elaborate quality of life assessment. (author)

  15. The development of manufacturing techniques and philosophies for the cost effective production of modern nuclear transport flasks

    International Nuclear Information System (INIS)

    Balmer, S.L.; Ward, S.

    1997-01-01

    Design changes to enhance the characteristics of a new generation of large transport flasks have created new challenges to manufacturers. New fabrication, manufacturing and handling techniques have been developed but often at significant costs. The paper examines these developments covering two main areas, welding and the application of neutron absorbing material. Whilst designers have looked at enhancing flask performance, they often fail to appreciate that ultimately whatever has been designed, has to be firstly sold' and then manufactured. Optimisation of design must therefore include due consideration of the ultimate clients cost structure and the manufacturing route. The paper suggests that the only way this can be achieved is to adopt a teaming approach between designers and manufacturers. The ultimate choice of manufacturer however is left to the designers who must consider competencies, track record and commitment to assistance prior to entering into an agreement. (Author)

  16. Modern Cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yuanzhong

    2002-06-21

    This book is one of a series in the areas of high-energy physics, cosmology and gravitation published by the Institute of Physics. It includes courses given at a doctoral school on 'Relativistic Cosmology: Theory and Observation' held in Spring 2000 at the Centre for Scientific Culture 'Alessandro Volta', Italy, sponsored by SIGRAV-Societa Italiana di Relativita e Gravitazione (Italian Society of Relativity and Gravitation) and the University of Insubria. This book collects 15 review reports given by a number of outstanding scientists. They touch upon the main aspects of modern cosmology from observational matters to theoretical models, such as cosmological models, the early universe, dark matter and dark energy, modern observational cosmology, cosmic microwave background, gravitational lensing, and numerical simulations in cosmology. In particular, the introduction to the basics of cosmology includes the basic equations, covariant and tetrad descriptions, Friedmann models, observation and horizons, etc. The chapters on the early universe involve inflationary theories, particle physics in the early universe, and the creation of matter in the universe. The chapters on dark matter (DM) deal with experimental evidence of DM, neutrino oscillations, DM candidates in supersymmetry models and supergravity, structure formation in the universe, dark-matter search with innovative techniques, and dark energy (cosmological constant), etc. The chapters about structure in the universe consist of the basis for structure formation, quantifying large-scale structure, cosmic background fluctuation, galaxy space distribution, and the clustering of galaxies. In the field of modern observational cosmology, galaxy surveys and cluster surveys are given. The chapter on gravitational lensing describes the lens basics and models, galactic microlensing and galaxy clusters as lenses. The last chapter, 'Numerical simulations in cosmology', deals with spatial and

  17. Image-guided radiotherapy for effective radiotherapy delivery

    CERN Document Server

    Karlsson, Ulf Lennart

    2016-01-01

    Image-guided radiotherapy (IGRT) is a new radiotherapy technology that combines the rapid dose fall off associated with intensity-modulated radiotherapy (IMRT) and daily tumor imaging allowing for high precision tumor dose delivery and effective sparing of surrounding normal organs. The new radiation technology requires close collaboration between radiologists, nuclear medicine specialists, and radiation oncologists to avoid marginal miss. Modern diagnostic imaging such as positron emission tomography (PET) scans, positron emission tomography with Computed Tomograpgy (PET-CT), and magnetic resonance imaging (MRI) allows the radiation oncologist to target the positive tumor with high accuracy. As the tumor is well visualized during radiation treatment, the margins required to avoid geographic miss can be safely reduced , thus sparing the normal organs from excessive radiation. When the tumor is located close to critical radiosensitive structures such as the spinal cord, IGRT can deliver a high dose of radiatio...

  18. An intra-patient dose-escalation study of disodium pamidronate plus radiotherapy versus radiotherapy alone for the treatment of osteolytic metastases. Monitoring of recalcification using image-processing techniques

    Energy Technology Data Exchange (ETDEWEB)

    Vassilis Kouloulias, E. [Dept. of Radiology, Aretaieion Univ. Hospital, Athens (Greece); Dept. of Electrical and Computer Engineering, Inst. of Communication and Computer Systems, National Technical Univ. of Athens (Greece); John Kouvaris, R.; Antypas, C.; Mystakidou, K.; Moulopoulos, A.; Lambros Vlahos, J. [Dept. of Radiology, Aretaieion Univ. Hospital, Athens (Greece); Matsopoulos, G.; Nikolaos Uzunoglu, C. [Dept. of Electrical and Computer Engineering, Inst. of Communication and Computer Systems, National Technical Univ. of Athens (Greece)

    2003-07-01

    Objective: To evaluate the clinical benefit and mainly to monitor quantitatively the recalcification of osteolytic lesions after radiotherapy with or without intravenous infusion of disodium pamidronate (DP) in different doses. Patients and Methods: 42 patients with solitary lytic metastasis in weight-bearing bones were studied. Primary endpoints were the mean value and energy of gray-level histogram in plain radiographs (MVGLH and EGLH) and relative electron density (RED) of CT scans in bone lesions. In eleven patients (group A) the DP dose was increased stepwise from 90 up to 180 mg (flat dose), while in other 15 patients (group B) a flat dose of 180 mg was administered intravenously in 2 h. In both groups, the first session of DP was given concurrently with local radiotherapy (30 Gy in ten fractions, 5 days a week). Another 16 patients (group C) underwent radiotherapy only. Results: Morbidity related to pamidronate was mild. Significant differences from the baseline (p < 0.05, Wilcoxon test) were recorded for MVGLH, EGLH and RED values, regarding all groups. Improvement was significantly higher in patients of group B versus A, while the results of pamidronate groups (A and B) were superior to group C, concerning the above indices (p < 0.05, Mann-Whitney test). Additionally, pamidronate groups had significantly lower skeletal morbidity than group C. Conclusion: The 2-h infusional flat dose of 180 mg every 4 weeks seems to be tolerable and superior to 90 mg regarding palliation and mainly recalcification of osteolytic lesions. Radiotherapy alone is effective but inferior to the combined treatment. Last but not least, the findings of MVGLH, EGLH and RED indicate an important increase in bone mass and bone formation, which was difficult to be identified visually by the experts. (orig.)

  19. The situation of radiotherapy in 2011

    International Nuclear Information System (INIS)

    2012-06-01

    Published within the frame of the French 2009-2013 cancer plan, this report proposes an analysis of the situation of radiotherapy in France. More particularly, it analyses the French offer in terms of radiotherapy treatments and the French position in Europe. A second part analyses equipment (accelerators and other equipment) and techniques aimed at radiotherapy treatment preparation and delivery. The following techniques are addressed: three-dimensional conformational, intensity modulation, intracranial and extracranial stereotactic, image-guided, total body irradiation, hadron-therapy, and peri-operative radiotherapy. The last parts analyse the activity of radiotherapy centres in terms of treated patients, of patient age structure, of sessions and preparations, and of treated pathologies, the medical and paramedical personnel in charge of radiotherapy, and financial and cost aspects

  20. Lessons in modern digital field geology: Open source software, 3D techniques, and the new world of digital mapping

    Science.gov (United States)

    Pavlis, Terry; Hurtado, Jose; Langford, Richard; Serpa, Laura

    2014-05-01

    Although many geologists refuse to admit it, it is time to put paper-based geologic mapping into the historical archives and move to the full potential of digital mapping techniques. For our group, flat map digital geologic mapping is now a routine operation in both research and instruction. Several software options are available, and basic proficiency with the software can be learned in a few hours of instruction and practice. The first practical field GIS software, ArcPad, remains a viable, stable option on Windows-based systems. However, the vendor seems to be moving away from ArcPad in favor of mobile software solutions that are difficult to implement without GIS specialists. Thus, we have pursued a second software option based on the open source program QGIS. Our QGIS system uses the same shapefile-centric data structure as our ArcPad system, including similar pop-up data entry forms and generic graphics for easy data management in the field. The advantage of QGIS is that the same software runs on virtually all common platforms except iOS, although the Android version remains unstable as of this writing. A third software option we are experimenting with for flat map-based field work is Fieldmove, a derivative of the 3D-capable program Move developed by Midland Valley. Our initial experiments with Fieldmove are positive, particularly with the new, inexpensive (potential for communicating the complexity of key exposures. For example, in studies of metamorphic structures we often search for days to find "Rosetta Stone" outcrops that display key geometric relationships. While conventional photographs rarely can capture the essence of the field exposure, capturing a true 3D representation of the exposure with multiple photos from many orientations can solve this communication problem. As spatial databases evolve these 3D models should be readily importable into the database.

  1. Radiotherapy apparatus

    International Nuclear Information System (INIS)

    Leung, P.M.; Webb, H.P.J.

    1985-01-01

    This invention relates to apparatus for applying intracavitary radiotherapy. In previously-known systems radioactive material is conveyed to a desired location within a patient by transporting a chain of balls pneumatically to and from an appropriately inserted applicator. According to this invention a ball chain for such a purpose comprises several radioactive balls separated by non-radioactive tracer balls of radiographically transparent material of lower density and surface hardness than the radioactive balls. The invention also extends to radiotherapy treatment apparatus comprising a storage, sorting and assembly system

  2. Highly Conformal Craniospinal Radiotherapy Techniques Can Underdose the Cranial Clinical Target Volume if Leptomeningeal Extension through Skull Base Exit Foramina is not Contoured.

    Science.gov (United States)

    Noble, D J; Ajithkumar, T; Lambert, J; Gleeson, I; Williams, M V; Jefferies, S J

    2017-07-01

    Craniospinal irradiation (CSI) remains a crucial treatment for patients with medulloblastoma. There is uncertainty about how to manage meningeal surfaces and cerebrospinal fluid (CSF) that follows cranial nerves exiting skull base foramina. The purpose of this study was to assess plan quality and dose coverage of posterior cranial fossa foramina with both photon and proton therapy. We analysed the radiotherapy plans of seven patients treated with CSI for medulloblastoma and primitive neuro-ectodermal tumours and three with ependymoma (total n = 10). Four had been treated with a field-based technique and six with TomoTherapy™. The internal acoustic meatus (IAM), jugular foramen (JF) and hypoglossal canal (HC) were contoured and added to the original treatment clinical target volume (Plan_CTV) to create a Test_CTV. This was grown to a test planning target volume (Test_PTV) for comparison with a Plan_PTV. Using Plan_CTV and Plan_PTV, proton plans were generated for all 10 cases. The following dosimetry data were recorded: conformity (dice similarity coefficient) and homogeneity index (D 2  - D 98 /D 50 ) as well as median and maximum dose (D 2% ) to Plan_PTV, V 95% and minimum dose (D 99.9% ) to Plan_CTV and Test_CTV and Plan_PTV and Test_PTV, V 95% and minimum dose (D 98% ) to foramina PTVs. Proton and TomoTherapy™ plans were more conformal (0.87, 0.86) and homogeneous (0.07, 0.04) than field-photon plans (0.79, 0.17). However, field-photon plans covered the IAM, JF and HC PTVs better than proton plans (P = 0.002, 0.004, 0.003, respectively). TomoTherapy™ plans covered the IAM and JF better than proton plans (P = 0.000, 0.002, respectively) but the result for the HC was not significant. Adding foramen CTVs/PTVs made no difference for field plans. The mean D min dropped 3.4% from Plan_PTV to Test_PTV for TomoTherapy™ (not significant) and 14.8% for protons (P = 0.001). Highly conformal CSI techniques may underdose meninges and CSF in the dural

  3. The Quality of Curative-intent Radiotherapy for Non-small Cell Lung Cancer in the UK.

    Science.gov (United States)

    McAleese, J; Baluch, S; Drinkwater, K

    2015-09-01

    Lung cancer is the leading cause of cancer-related death in the UK. The quality of curative-intent radiotherapy is associated with better outcomes. National quality standards from the National Institute for Health and Care Excellence (NICE) on patient work-up and treatment selection were used, with guidance from the Royal College of Radiologists on the technical delivery of radiotherapy, to assess the quality of curative-intent non-small cell lung cancer radiotherapy and to describe current UK practice. Radiotherapy departments completed one questionnaire for each patient started on curative-intent radiotherapy for 8 weeks in 2013. Eighty-two per cent of centres returned a total of 317 proformas. Patient selection with positron emission tomography/computed tomography, performance status and Forced Expiratory Volume in 1 second (FEV1) was usually undertaken. Fifty-six per cent had pathological confirmation of mediastinal lymph nodes and 22% staging brain scans; 20% were treated with concurrent chemoradiation, 12% with Stereotactic Ablative Radiotherapy (SABR) and 8% with Continuous Hyperfractionated Accelerated Radiotherapy (CHART). Sixty-three per cent of patients received 55 Gy/20 fractions. Although respiratory compensation was routinely undertaken, only 33% used four-dimensional computed tomography. Seventy per cent of patients were verified with cone beam computed tomography. There was consistency of practice in dosimetric constraints for organs at risk and follow-up. This audit has described current UK practice. The latest recommendations for patient selection with pathological confirmation of mediastinal lymph nodes, brain staging and respiratory function testing are not universally followed. Although there is evidence of increasing use of newer techniques such as four-dimensional computed tomography and cone beam image-guided radiotherapy, there is still variability in access. Efforts should be made to improve access to modern technologies and quality

  4. Magnetic Resonance Imaging and conformal radiotherapy: Characterization of MRI alone simulation for conformal radiotherapy. Development and evaluation of an automatic volumes of interest segmentation tool for prostate cancer radiotherapy

    International Nuclear Information System (INIS)

    Pasquier, David

    2006-01-01

    Radiotherapy is a curative treatment of malignant tumours. Radiotherapy techniques considerably evolved last years with the increasing integration of medical images in conformal radiotherapy. This technique makes it possible to elaborate a complex ballistics conforming to target volume and sparing healthy tissues. The examination currently used to delineate volumes of interest is Computed Tomography (CT), on account of its geometrical precision and the information that it provides on electronic densities needed to dose calculation. Magnetic Resonance Imaging (MRI) ensures a more precise delineation of target volumes in many locations, such as pelvis and brain. For pelvic tumours, the use of MRI needs image registration, which complicates treatment planning and poses the problem of the lack of in vivo standard method of validation. The obstacles in the use of MRI alone in treatment planning were evaluated. Neither geometrical distortion linked with the system and the patient nor the lack of information on electronic densities represent stumbling obstacles. Distortion remained low even in edge of large field of view on modern machines. The assignment of electronic densities to bone structures and soft tissues in MR images permitted to obtain equivalent dosimetry to that carried out on the original CT, with a good reproducibility and homogeneous distribution within target volume. The assignment of electronic densities could not be carried out using 20 MV photons and suitable ballistics. The development of Image Guided Radiotherapy could facilitate the use of MRI alone in treatment planning. Target volumes and organ at risk delineation is a time consuming task in radiotherapy planning. We took part in the development and evaluated a method of automatic and semi automatic delineation of volumes of interest from MRI images for prostate cancer radiotherapy. For prostate and organ at risk automatic delineation an organ model-based method and a seeded region growing method

  5. Why and how to spare the hippocampus during brain radiotherapy: the developing role of hippocampal avoidance in cranial radiotherapy

    International Nuclear Information System (INIS)

    Kazda, Tomas; Slampa, Pavel; Laack, Nadia N; Jancalek, Radim; Pospisil, Petr; Sevela, Ondrej; Prochazka, Tomas; Vrzal, Miroslav; Burkon, Petr; Slavik, Marek; Hynkova, Ludmila

    2014-01-01

    The goal of this review is to summarize the rationale for and feasibility of hippocampal sparing techniques during brain irradiation. Radiotherapy is the most effective non-surgical treatment of brain tumors and with the improvement in overall survival for these patients over the last few decades, there is an effort to minimize potential adverse effects leading to possible worsening in quality of life, especially worsening of neurocognitive function. The hippocampus and associated limbic system have long been known to be important in memory formation and pre-clinical models show loss of hippocampal stem cells with radiation as well as changes in architecture and function of mature neurons. Cognitive outcomes in clinical studies are beginning to provide evidence of cognitive effects associated with hippocampal dose and the cognitive benefits of hippocampal sparing. Numerous feasibility planning studies support the feasibility of using modern radiotherapy systems for hippocampal sparing during brain irradiation. Although results of the ongoing phase II and phase III studies are needed to confirm the benefit of hippocampal sparing brain radiotherapy on neurocognitive function, it is now technically and dosimetrically feasible to create hippocampal sparing treatment plans with appropriate irradiation of target volumes. The purpose of this review is to provide a brief overview of studies that provide a rationale for hippocampal avoidance and provide summary of published feasibility studies in order to help clinicians prepare for clinical usage of these complex and challenging techniques

  6. Digital linear accelerator: The advantages for radiotherapy

    International Nuclear Information System (INIS)

    Andric, S.; Maksimovic, M.; Dekic, M.; Clark, T.

    1998-01-01

    Technical performances of Digital Linear Accelerator were presented to point out its advantages for clinical radiotherapy treatment. The accelerator installation is earned out at Military Medical Academy, Radiotherapy Department, by Medes and Elekta companies. The unit offers many technical advantages with possibility of introduction new conformal treatment techniques as stereotactic radiosurgery, total body and total skin irradiation. In the paper are underlined advantages in relation to running conventional accelerator units at Yugoslav radiotherapy departments, both from technical and medical point of view. (author)

  7. Modernization of the turbine control technique and the turbine hydraulics aimed to improved maneuverability in the load range, system safety and plant availability, plant transparency for diagnosis and long-term performance

    International Nuclear Information System (INIS)

    Baran, Detlef

    2012-01-01

    In the contribution H.Mauell GmbH presents modernization projects for the nuclear power plants Tihange-3 and Doel-4. The project volume included control technique and the turbine hydraulics for the steam turbo generating set including turbine auxiliary devices and two turbine feeding pumps. The modernizations were successfully completed in 2010 and 2011, respectively. The nuclear power plants are trouble-free operated.

  8. Inspecting what you expect: Applying modern tools and techniques to evaluate the effectiveness of household energy interventions

    Science.gov (United States)

    Pillarisetti, Ajay

    Exposure to fine particles (PM2.5) resulting from solid fuel use for household energy needs - including cooking, heating, and lighting - is one of the leading causes of ill-health globally and is responsible for approximately 4 million premature deaths and 84 million lost disability-adjusted life years globally. The well-established links between cooking and ill-health are modulated by complex social, behavioral, technological, and environmental issues that pose unique challenges to efforts that seek to reduce this large health burden. Despite growing interest in the field - and numerous technical solutions that, in the laboratory at least, reduce emissions of harmful air pollutants from solid fuel combustion - there exists a need for refined tools, models, and techniques (1) for measuring environmental pollution in households using solid fuel, (2) for tracking adoption of interventions, and (3) for estimating the potential health benefits attributable to an intervention. Part of the need for higher spatial and temporal resolution data on particular concentrations and dynamics is being met by low-cost sensing platforms that provide large amounts of time-resolved data on critical parameters of interest, including PM2.5 concentrations and time-of-use metrics for heat-generating appliances, like stoves. Use of these sensors can result in non-trivial challenges, including those related to data management and analysis, and field logistics, but also enables novel lines of inquiry and insight. Chapter 2 presents a long-term deployment of real-time PM2.5 sensors in rural, solid-fuel-using kitchens, specifically seeking to evaluate how well commonly measured 24 or 48-hour samples represent long-term means. While short-term measures were poor predictors of long-term means, the dataset enabled evaluation of numerous sampling strategies - including sampling once per week, month, or season - that had much lower errors and higher probabilities of estimating the true mean

  9. Presentation of a 3D conformal radiotherapy technique for head-and-neck tumors resulting in substantial protection of the parotid glands

    International Nuclear Information System (INIS)

    Kuhnt, T.; Janich, M.; Gerlach, R.; Haensgen, G.; Goetz, U.; Chiricuta, I.C.

    2006-01-01

    Purpose: the aim of this study was to improve the irradiation technique for the treatment of head-and-neck tumors and, in particular, to make use of the advantages found in modern 3D planning to protect the parotid glands. Patients and methods: for this investigation the 3D dataset of a standard patient with oropharyngeal carcinoma of UICC stage IVA was used. In the CT scans (slice thickness 5 mm) the planning target volume (PTV), the boost volume and both parotids were delineated. Three different techniques were calculated for two different dose levels (50 Gy for PTV and 64 Gy for boost volume, using single doses of 2 Gy). For technique 1 (T1) a parallel opposed field photon/electron irradiation was designed, for technique 2 (T2) an opposed/arc field irradiation was employed, and for technique 3 (T3) a combination of a static coplanar and arc field irradiation was designed. The sum doses D min , D max and D mean for PTV, boost volume, and ipsilateral and contralateral parotid gland were evaluated, and the time needed for calculation of the plans was also determined. Results: for all techniques used, the calculated doses in the PTV (D min 5.6 ± 0.1 Gy, D max 73.7 ± 0.1 Gy, and D mean 57.9 ± 0.5 Gy) and in the boost volume (D min 46.9 ± 1.5 Gy, D max 73.8 ± 0.12 Gy, and D mean 65.8 ± 0.9 Gy) were equal. Significant differences were found regarding the three different techniques, e.g., for the ipsilateral parotid gland D min (T1 = 47.4, T2 = 50.6, and T3 = 38.4 Gy) as well as for the contralateral parotid gland D min (T1 = 42.1, T2 = 44.2, and T3 = 17.8 Gy) and D mean (T1 = 51.3, T2 = 52.8, and T3 = 32.6 Gy). Regarding the three different techniques, significant differences were found in favor of T3. The determined planning times were as follows: T1 = 90, T2 = 60, and T3 = 90 min. Conclusion: the combination of static coplanar and arc field technique (T3) resulted in a substantially better protection as compared to both other techniques. This was especially the

  10. Three-dimensional treatment planning for postoperative radiotherapy in patients with node-positive cervical cancer. Comparison between a conventional and a conformal technique

    Energy Technology Data Exchange (ETDEWEB)

    Olofsen-van Acht, M.J.J.; Quint, S.; Seven, M.; Berg, H.A. van den; Levendag, P.C. [University Hospital Rotterdam (Netherlands). Dept. of Radiation Oncology; Santvoort, J.P.C. van [University Hospital Rotterdam (Netherlands). Subdivision of Clinical Physics; Logmans, A. [University Hospital Rotterdam (Netherlands). Dept. of Gynecologic Oncology

    1999-09-01

    Purpose: Reduction of irradiated small bowel volume, using a conformal three-dimensional treatment planning technique in postoperative radiotherapy of cervical cancer patients. Patients and Methods: Large gynecological treatment fields including the para-aortic nodes were analyzed in 15 patients. A conventional treatment plan with anterior and posterior (AP-PA) parallel opposed fields and a 3D 4-field conformal radiotherapy plan with a central blocking of small bowel were compared for each patient. Dose-volume histograms and dose parameters were established. Because of the tolerance constraints of the small bowel, the cumulative dose applied to the target was 48.6 Gy. Results: The mean Tumor Control Probability (TCP) values for both the conventional and the conformal technique were 0.60 and 0.61, respectively, with ranges of 0.56 to 0.67 and 0.57 to 0.66, respectively. The mean volume receiving 95% or more of the prescribed dose (V95) of the small bowel was 47.6% (32.5 to 66.3%) in the AP-PA technique and 14.9% (7.0 to 22.5%) in the conformal technique (p<0.001), indicating a significant reduction in irradiated volume of small bowel in the higher dose range. The mean Normal Tissue Complication Probability (NTCP) decreased from 0.11 to 0.03 with the conformal plan. In patients who received a pedicled omentoplasty during surgery, the mean V95 for small bowel could be reduced to 8.5% (7.0 to 9.9%). The mean median dose to the kidneys was only slightly elevated in the conformal treatment. Especially the mean dose to the right kidney in conventional vs conformal treatment was 3.3 vs 7.9 Gy. The mean near-minimum dose (D95) to the rectosigmoid decreased from 48.4 to 30.1 Gy in the conformal plan compared to the conventional plan. Conclusion: The small bowel dose can be significantly reduced with 3D treatment planning, particularly if a predicled omentoplasty is performed. This allows dose escalation to the tumor region without unacceptable toxicity for the small bowel

  11. Why Radiotherapy Works. Chapter 6

    International Nuclear Information System (INIS)

    Tashiro, S.; Nishibuchi, I.; Wondergem, J.

    2017-01-01

    The history of radiotherapy began in 1895, when Röntgen discovered X rays, and in the following year, radiation was used for medical treatment. In the early days, the development of radiotherapy was based extensively on empiricism. Radiotherapists worked closely with radiation biologists in attempting to describe and understand the phenomena produced by ionizing radiation in the clinic and in biological systems. During the ensuing 120 years, radiotherapy has been improved significantly and, in addition to radiation biology, medical physics has played an important role in the design and development of equipment, quality assurance and dosimetry. Over recent decades, advances have been made in the field of molecular biology. Currently available techniques enable us to elucidate the molecular mechanisms of cellular response to ionizing irradiation, and it is anticipated that the role and contributions of radiation biology in radiotherapy will remain relevant. This chapter describes the clinically important biological points, including knowledge from current molecular biology.

  12. Small animal radiotherapy research platforms

    Energy Technology Data Exchange (ETDEWEB)

    Verhaegen, Frank; Granton, Patrick [Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Tryggestad, Erik, E-mail: frank.verhaegen@maastro.nl [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD 21231 (United States)

    2011-06-21

    Advances in conformal radiation therapy and advancements in pre-clinical radiotherapy research have recently stimulated the development of precise micro-irradiators for small animals such as mice and rats. These devices are often kilovolt x-ray radiation sources combined with high-resolution CT imaging equipment for image guidance, as the latter allows precise and accurate beam positioning. This is similar to modern human radiotherapy practice. These devices are considered a major step forward compared to the current standard of animal experimentation in cancer radiobiology research. The availability of this novel equipment enables a wide variety of pre-clinical experiments on the synergy of radiation with other therapies, complex radiation schemes, sub-target boost studies, hypofractionated radiotherapy, contrast-enhanced radiotherapy and studies of relative biological effectiveness, to name just a few examples. In this review we discuss the required irradiation and imaging capabilities of small animal radiation research platforms. We describe the need for improved small animal radiotherapy research and highlight pioneering efforts, some of which led recently to commercially available prototypes. From this, it will be clear that much further development is still needed, on both the irradiation side and imaging side. We discuss at length the need for improved treatment planning tools for small animal platforms, and the current lack of a standard therein. Finally, we mention some recent experimental work using the early animal radiation research platforms, and the potential they offer for advancing radiobiology research. (topical review)

  13. Small animal radiotherapy research platforms

    Science.gov (United States)

    Verhaegen, Frank; Granton, Patrick; Tryggestad, Erik

    2011-06-01

    Advances in conformal radiation therapy and advancements in pre-clinical radiotherapy research have recently stimulated the development of precise micro-irradiators for small animals such as mice and rats. These devices are often kilovolt x-ray radiation sources combined with high-resolution CT imaging equipment for image guidance, as the latter allows precise and accurate beam positioning. This is similar to modern human radiotherapy practice. These devices are considered a major step forward compared to the current standard of animal experimentation in cancer radiobiology research. The availability of this novel equipment enables a wide variety of pre-clinical experiments on the synergy of radiation with other therapies, complex radiation schemes, sub-target boost studies, hypofractionated radiotherapy, contrast-enhanced radiotherapy and studies of relative biological effectiveness, to name just a few examples. In this review we discuss the required irradiation and imaging capabilities of small animal radiation research platforms. We describe the need for improved small animal radiotherapy research and highlight pioneering efforts, some of which led recently to commercially available prototypes. From this, it will be clear that much further development is still needed, on both the irradiation side and imaging side. We discuss at length the need for improved treatment planning tools for small animal platforms, and the current lack of a standard therein. Finally, we mention some recent experimental work using the early animal radiation research platforms, and the potential they offer for advancing radiobiology research.

  14. Small animal radiotherapy research platforms

    International Nuclear Information System (INIS)

    Verhaegen, Frank; Granton, Patrick; Tryggestad, Erik

    2011-01-01

    Advances in conformal radiation therapy and advancements in pre-clinical radiotherapy research have recently stimulated the development of precise micro-irradiators for small animals such as mice and rats. These devices are often kilovolt x-ray radiation sources combined with high-resolution CT imaging equipment for image guidance, as the latter allows precise and accurate beam positioning. This is similar to modern human radiotherapy practice. These devices are considered a major step forward compared to the current standard of animal experimentation in cancer radiobiology research. The availability of this novel equipment enables a wide variety of pre-clinical experiments on the synergy of radiation with other therapies, complex radiation schemes, sub-target boost studies, hypofractionated radiotherapy, contrast-enhanced radiotherapy and studies of relative biological effectiveness, to name just a few examples. In this review we discuss the required irradiation and imaging capabilities of small animal radiation research platforms. We describe the need for improved small animal radiotherapy research and highlight pioneering efforts, some of which led recently to commercially available prototypes. From this, it will be clear that much further development is still needed, on both the irradiation side and imaging side. We discuss at length the need for improved treatment planning tools for small animal platforms, and the current lack of a standard therein. Finally, we mention some recent experimental work using the early animal radiation research platforms, and the potential they offer for advancing radiobiology research. (topical review)

  15. The evolution of rectal and urinary toxicity and immune response in prostate cancer patients treated with two three-dimensional conformal radiotherapy techniques

    Czech Academy of Sciences Publication Activity Database

    Vránová, J.; Vinakurau, S.; Richter, J.; Starec, M.; Fišerová, Anna; Rosina, J.

    2011-01-01

    Roč. 2, č. 6 (2011), s. 1-13 ISSN 1748-717X R&D Projects: GA AV ČR IAA500200620 Institutional research plan: CEZ:AV0Z50200510 Keywords : 3-dimensional conformal radiotherapy (3DCRT) * gastrointestinal and genitourinary toxicity * prostate cancer Subject RIV: EC - Immunology Impact factor: 2.321, year: 2011

  16. SU-F-T-500: The Effectiveness of a Patient Specific Bolus Made by Using Three-Dimensional Printing Technique in Photon Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, K; Yuasa, Y [Department of Radiological Technology, Yamaguchi University Hospital (Japan); Shiinoki, T; Hanazawa, H; Shibuya, K [Department of Radiation Oncology, Graduate school of Medicine, Yamaguchi University (Japan)

    2016-06-15

    Purpose: A commercially available bolus (commercial-bolus) would not completely contact with the irregular shape of a patient’s skin. The purposes of this study were to customize a patient specific three-dimensional (3D) bolus using a 3D printer (3D-bolus) and to evaluate its clinical feasibility for photon radiotherapy. Methods: The 3D-bolus was designed using a treatment planning system (TPS) in DICOM-RT format. To print the 3D bolus, the file was converted into stereolithography format. To evaluate its physical characteristics, plans were created for water equivalent phantoms without the bolus, with the 3D-bolus printed in a flat form, and with the virtual bolus which supposed a commercial-bolus. These plans were compared with the percent depth dose (PDD) measured from the TPS. Furthermore, to evaluate its clinical feasibility, the treatment plans were created for RANDO phantoms without the bolus and with the 3D-bolus which was customized for contacting with the surface of the phantom. Both plans were compared with the dose volume histogram (DVH) of the target volume. Results: In the physical evaluation, dmax of the plan without the bolus, with the 3D-bolus, and with the virtual bolus were 2.2 cm, 1.6 cm, and 1.7 cm, respectively. In the evaluation of clinical feasibility, for the plan without the bolus, Dmax, Dmin, Dmean, D90%, and V90% of the target volume were 102.6 %, 1.6 %, 88.8 %, 57.2 %, and 69.3 %, respectively. By using the 3D-bolus, the prescription dose could be delivered to at least 90 % of the target volume, Dmax, Dmin, Dmean, D90%, and V90% of the target volume were 104.3 %, 91.6 %, 92.1 %, 91.7 %, and 98.0 %, respectively. The 3D-bolus has the potential to be useful for providing effective dose coverage in the buildup region. Conclusion: A 3D-bolus produced using 3D printing technique is comparable to a commercially available bolus.

  17. SU-F-T-500: The Effectiveness of a Patient Specific Bolus Made by Using Three-Dimensional Printing Technique in Photon Radiotherapy

    International Nuclear Information System (INIS)

    Fujimoto, K; Yuasa, Y; Shiinoki, T; Hanazawa, H; Shibuya, K

    2016-01-01

    Purpose: A commercially available bolus (commercial-bolus) would not completely contact with the irregular shape of a patient’s skin. The purposes of this study were to customize a patient specific three-dimensional (3D) bolus using a 3D printer (3D-bolus) and to evaluate its clinical feasibility for photon radiotherapy. Methods: The 3D-bolus was designed using a treatment planning system (TPS) in DICOM-RT format. To print the 3D bolus, the file was converted into stereolithography format. To evaluate its physical characteristics, plans were created for water equivalent phantoms without the bolus, with the 3D-bolus printed in a flat form, and with the virtual bolus which supposed a commercial-bolus. These plans were compared with the percent depth dose (PDD) measured from the TPS. Furthermore, to evaluate its clinical feasibility, the treatment plans were created for RANDO phantoms without the bolus and with the 3D-bolus which was customized for contacting with the surface of the phantom. Both plans were compared with the dose volume histogram (DVH) of the target volume. Results: In the physical evaluation, dmax of the plan without the bolus, with the 3D-bolus, and with the virtual bolus were 2.2 cm, 1.6 cm, and 1.7 cm, respectively. In the evaluation of clinical feasibility, for the plan without the bolus, Dmax, Dmin, Dmean, D90%, and V90% of the target volume were 102.6 %, 1.6 %, 88.8 %, 57.2 %, and 69.3 %, respectively. By using the 3D-bolus, the prescription dose could be delivered to at least 90 % of the target volume, Dmax, Dmin, Dmean, D90%, and V90% of the target volume were 104.3 %, 91.6 %, 92.1 %, 91.7 %, and 98.0 %, respectively. The 3D-bolus has the potential to be useful for providing effective dose coverage in the buildup region. Conclusion: A 3D-bolus produced using 3D printing technique is comparable to a commercially available bolus.

  18. SU-D-213-03: Towards An Optimized 3D Scintillation Dosimetry Tool for Quality Assurance of Dynamic Radiotherapy Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Rilling, M [Département de physique, de génie physique et d’optique, Université Laval, Quebec City, QC (Canada); Centre de Recherche sur le Cancer, Hôtel-Dieu de Québec, Quebec City, QC (Canada); Département de radio-oncologie, CHU de Québec, Quebec City, QC (Canada); Center for Optics, Photonics and Lasers, Université Laval, Quebec City, QC, CA (Canada); Goulet, M [Département de radio-oncologie, CHU de Québec, Quebec City, QC (Canada); Thibault, S [Département de physique, de génie physique et d’optique, Université Laval, Quebec City, QC (Canada); Center for Optics, Photonics and Lasers, Université Laval, Quebec City, QC, CA (Canada); Archambault, L [Département de physique, de génie physique et d’optique, Université Laval, Quebec City, QC (Canada); Centre de Recherche sur le Cancer, Hôtel-Dieu de Québec, Quebec City, QC (Canada); Département de radio-oncologie, CHU de Québec, Quebec City, QC (Canada)

    2015-06-15

    Purpose: The purpose of this work is to simulate a multi-focus plenoptic camera used as the measuring device in a real-time three-dimensional scintillation dosimeter. Simulating and optimizing this realistic optical system will bridge the technological gap between concept validation and a clinically viable tool that can provide highly efficient, accurate and precise measurements for dynamic radiotherapy techniques. Methods: The experimental prototype, previously developed for proof of concept purposes, uses an off-the-shelf multi-focus plenoptic camera. With an array of interleaved microlenses of different focal lengths, this camera records spatial and angular information of light emitted by a plastic scintillator volume. The three distinct microlens focal lengths were determined experimentally for use as baseline parameters by measuring image-to-object magnification for different distances in object space. A simulated plenoptic system was implemented using the non-sequential ray tracing software Zemax: this tool allows complete simulation of multiple optical paths by modeling interactions at interfaces such as scatter, diffraction, reflection and refraction. The active sensor was modeled based on the camera manufacturer specifications by a 2048×2048, 5 µm-pixel pitch sensor. Planar light sources, simulating the plastic scintillator volume, were employed for ray tracing simulations. Results: The microlens focal lengths were determined to be 384, 327 and 290 µm. A realistic multi-focus plenoptic system, with independently defined and optimizable specifications, was fully simulated. A f/2.9 and 54 mm-focal length Double Gauss objective was modeled as the system’s main lens. A three-focal length hexagonal microlens array of 250-µm thickness was designed, acting as an image-relay system between the main lens and sensor. Conclusion: Simulation of a fully modeled multi-focus plenoptic camera enables the decoupled optimization of the main lens and microlens

  19. Proceedings of 19. symposium on experimental radiotherapy and clinical radiobiology

    International Nuclear Information System (INIS)

    Baumann, Michael; Dahm-Daphi, Jochen; Dikomey, Ekkehard; Petersen, Cordula; Rodemann, H. Peter; Zips, Daniel

    2010-01-01

    The proceedings include review contributions on radio-oncology, and new radiation technologies and molecular prediction; and poster sessions on the following topics: hypoxia; molecular mechanisms of radiation resistance; molecular targeting; DNA repair; biological imaging; biology of experimental radiations; normal tissue toxicity; modern radiotherapy; tumor hypoxia and metabolic micro milieu; immune system and radiotherapy.

  20. Three dimensional conformal postoperative radiotherapy for ...

    African Journals Online (AJOL)

    Introduction: Postoperative radiotherapy of the parotid gland could be achieved with various radiotherapy techniques. However they irradiate differently the surrounding organs at risk (OARs) in particular the cochlea, oral cavity & contralateral parotid causing significant increase in the risk of oral mucositis, xerostomia, and ...

  1. Radiotherapy in Cancer Management

    International Nuclear Information System (INIS)

    Abdel-Wahab, M.

    2015-01-01

    Radiotherapy has been used for curative or palliative treatment of cancer, either alone or increasingly as part of a multimodality approach in conjunction with chemotherapy, immunotherapy or surgery. Radiation must be delivered in the safest and most effective way. The use of radiologic and nuclear medicine diagnostic techniques, e.g., the use of CT (Computerized Tomography) and PET/CT allow better detection and staging of diseases by displaying both morphological and functional abnormalities within the affected organs and are essential in the process of radiotherapy planning. Technical advances in radiotherapy have allowed better targeting of tumors, sparing of normal tissue and, in the case of radiosurgery, a decrease in the number of treatments. The IAEA Programme in Human Health aims to enhance the capabilities in Member States to address needs related to the treatment of diseases, including cancer, through the application of nuclear techniques. The Programme supports quality assurance in radiation medicine; DIRAC, the only radiation oncology-specific resource database world-wide; significant, innovative education and training programmes through telemedicine and e-learning accessible via the human health campus website. Technical expertise for country– and region–specific technical cooperation radiation-medicine projects is provided to establish or enhance radiation medicine worldwide. (author)

  2. Guide of external radiotherapy procedures 2007

    International Nuclear Information System (INIS)

    Anon.

    2008-01-01

    This work aims at participating in the permanent optimization of the returned medical service and the ratio profit-risk. This first version of the guide of external radiotherapy procedures 2007 processes only techniques of external radiotherapy, by opposition to the techniques of brachytherapy which use radioactive sources (iridium 192 , iodine 125 , cesium 137 ) placed in the contact of the tumor to be irradiated. Only, also, will be considered the irradiations of the most frequent cunning(malignant) tumors with the exception of the radiotherapy of the mild pathologies and the re-irradiations after a first radiotherapy. The first part is shared in eight chapters as follow: introduction, the steps of a treatment by radiotherapy, infrastructure, equipment and human resources, radiobiology mechanism of action of ionising radiations in radiotherapy, dose in radiotherapy, quality of treatment and radiation protection of patients in radiotherapy, prevention and risk management in radiotherapy, quality assurance and radiation protection for the pediatrics cancers and the case of pregnant women. The second part gives the tumoral localizations and the procedures; the third part is a glossary and different annexes such regulations and legislative texts. (N.C.)

  3. Palliative Radiotherapy

    International Nuclear Information System (INIS)

    Salinas, J.

    2003-01-01

    Palliative care does not attempt to prolong survival but to the achieve the highest quality of life both for the patient and their family covering their physical, psychological, social and spiritual needs. Radiotherapy (RT), one of the most important therapeutic modalities, has a great significance in palliative medicine for cancer since it attempts to reduce as much as possible the acute reaction associated with the treatment for the patient. (Author)

  4. Extracorporeal Membrane Oxygenation and Modern Detoxification Techniques in a Puerpera with Viral and Bacterial Pneumonia Caused by Flu A(H1N1 Virus

    Directory of Open Access Journals (Sweden)

    R. A. Kornelyuk

    2017-01-01

    Full Text Available Outbreaks of viral infections have become a global healthcare challenge over the last decade. The 2009—2010 flu A (H1N1 outbreak resulted in global pandemia, associated with high morbidity and mortality reaching 31%. Another flu A (H1N1 outbreak occurred in 2015—2016. There is a strong probability that it may be repeated in the future. This infection is associated with its high incidence among pregnant women. There are some published reports describing the efficacy and safety of veno%venous extracorporeal membrane oxygenation (ECMO in patients with severe acute respiratory distress syndrome that is refractory to standard therapeutic options. The article presents a clinical case of a successful use of extracorporeal membrane oxygenation and intermittent renal replacement therapy in a puerpera with acute respiratory distress syndrome caused by flu A (H1N1-related severe viral and bacterial pneumonia. The positive effects of the combination of veno%venous extracorporeal membrane oxygenation and modern detoxification techniques have been demonstrated. Revealed organizational problemswere related to selection criteria for prescription of extracorporeal gas exchange, as well as to carrying out the procedure in an institution in the deficiency of the experienced staff and corresponding equipment.

  5. Monte Carlo techniques in radiation therapy

    CERN Document Server

    Verhaegen, Frank

    2013-01-01

    Modern cancer treatment relies on Monte Carlo simulations to help radiotherapists and clinical physicists better understand and compute radiation dose from imaging devices as well as exploit four-dimensional imaging data. With Monte Carlo-based treatment planning tools now available from commercial vendors, a complete transition to Monte Carlo-based dose calculation methods in radiotherapy could likely take place in the next decade. Monte Carlo Techniques in Radiation Therapy explores the use of Monte Carlo methods for modeling various features of internal and external radiation sources, including light ion beams. The book-the first of its kind-addresses applications of the Monte Carlo particle transport simulation technique in radiation therapy, mainly focusing on external beam radiotherapy and brachytherapy. It presents the mathematical and technical aspects of the methods in particle transport simulations. The book also discusses the modeling of medical linacs and other irradiation devices; issues specific...

  6. Education in physics of radiotherapy

    International Nuclear Information System (INIS)

    Kessler, Judith; Feld, Diana B.; Portillo, Perla A.; Casal, Mariana R.; Menendez, Pablo R.

    2008-01-01

    Radiotherapy is the clinical application which requires the highest precision in dose delivery because of the very high doses administrated to patients, taking into account that new diagnostic methods and new modalities and treatment machines give greater possibilities of dose escalation. These higher doses may also produce serious side effects if not accurately administered. High qualified personnel is therefore needed for dealing with these new complex modalities, assuring that dose prescribed is correctly administered and providing adequate radiation protection to patients, public and staff. Education in Physics of Radiotherapy aims to provide students with solid theoretical and practical basis in order to be able to work with great responsibility and understanding in a Radiotherapy Department and assure that appropriate radiation protection to patients, public and staff. Since 1964 the National Atomic Energy Commission (CNEA) gives course related to Radiotherapy and since 2002, due to a collaborative project, these courses are given at the Oncology Institute 'Angel H. Roffo' (IOAR) which belongs to the University of Buenos Aires (UBA). The IOAR is well equipped in Radiotherapy and new techniques are continuously introduced. That is why, being a University Institution and having highly specialized staff, it is the ideal hospital for teaching Radiotherapy in Buenos Aires, not only for regular courses but also for implementing workshops, seminars and updating courses as well. Continuous education helps to create and increase awareness of the importance of radiation protection in patients as well as in public and staff. (author)

  7. Breath-hold technique in conventional APPA or intensity-modulated radiotherapy for Hodgkin's lymphoma. Comparison of ILROG IS-RT and the GHSG IF-RT

    Energy Technology Data Exchange (ETDEWEB)

    Kriz, Jan; Spickermann, Max; Lehrich, Philipp; Reinartz, Gabriele; Eich, Hans; Haverkamp, Uwe [University of Muenster, Department of Radiation Oncology, Muenster (Germany); Schmidberger, Heinz [University Mainz, Department of Radiation Oncology, Mainz (Germany)

    2015-09-15

    The present study addresses the role of intensity-modulated radiotherapy (IMRT) in contrast to standard RT (APPA) for patients with Hodgkin's lymphoma (HL) with a focus on deep inspiration breath-hold (DIBH) technique and a comparison between the International Lymphoma Radiation Oncology Group (ILROG) Involved Site Radiotherapy (IS-RT) versus the German Hodgkin Study Group (GHSG) Involved Field Radiotherapy (IF-RT). APPA treatment and 2 IMRT plans were compared for 11 patients with HL. Furthermore, treatment with DIBH versus free breathing (FB) and two different treatment volumes, i.e. IF-RT versus IS-RT, were compared. IMRT was planned as a sliding-window technique with 5 and 7 beam angles. For each patient 12 different treatment plans were calculated (132 plans). Following organs at risk (OAR) were analysed: lung, heart, spinal cord, oesophagus, female breast and skin. Comparisons of the different values with regard to dose-volume histograms (DVH), conformity and homogeneity indices were made. IS-RT reduces treatment volumes. With respect to the planning target volume (PTV), IMRT achieves better conformity but the same homogeneity. Regarding the D{sub mean} for the lung, IMRT shows increased doses, while RT in DIBH reduces doses. The IMRT shows improved values for D{sub max} concerning the spinal cord, whereas the APPA shows an improved D{sub mean} of the lung and the female breast. IS-RT reduces treatment volumes. Intensity-modulated radiotherapy shows advantages in the conformity. Treatment in DIBH also reduces the dose applied to the lungs and the heart. (orig.) [German] Ziel dieser Auswertung ist es, die konventionelle APPA-Feldanordnung mit der Intensitaetsmodulierten Radiotherapie (IMRT) bei Patienten mit Hodgkin-Lymphom (HL) zu vergleichen. Ein besonderer Fokus liegt hierbei auf der Bestrahlung in tiefer Inspiration und Atemanhaltetechnik (DIBH). Des Weiteren wurde die ''Involved-site''-Radiotherapie (IS-RT) der International

  8. Modernity: Are Modern Times Different?

    Directory of Open Access Journals (Sweden)

    Lynn Hunt

    2014-12-01

    Full Text Available “Modernity” has recently been the subject of considerable discussion among historians. This article reviews some of the debates and argues that modernity is a problematic concept because it implies a complete rupture with “traditional” ways of life. Studies of key terms are undertaken with the aid of Google Ngrams. These show that “modernity,” “modern times,” and “traditional” —in English and other languages— have a history of their own. A brief analysis of the shift from a self oriented toward equilibrium to a self oriented toward stimulation demonstrates that modernity is not necessary to historical analysis.

  9. Intensity modulation in breast radiotherapy: Development of an innovative field-in-field technique at Institut Gustave-Roussy; Modulation d'intensite en radiotherapie mammaire: developpement d'une methode innovante de champ dans le champ a l'institut Gustave-Roussy

    Energy Technology Data Exchange (ETDEWEB)

    Heymann, S.; Bourhis, J.; Bourgier, C. [Departement d' oncologie radiotherapie, institut de cancerologie Gustave-Roussy, 114, rue edouard-Vaillant, 94805 Villejuif (France); Verstraet, R.; Pichenot, C.; Vergne, E.; Lefkopoulos, D. [Departement de physique, institut de cancerologie Gustave-Roussy, 114, rue edouard-Vaillant, 94805 Villejuif (France); Husson, F.; Kafrouni, H.; Mahe, J.; Kandalaft, B. [Societe Dosisoft, 45/47, avenue Carnot, 94230 Cachan (France); Marsiglia, H. [Departement d' oncologie radiotherapie, institut de cancerologie Gustave-Roussy, 114, rue edouard-Vaillant, 94805 Villejuif (France); Universite de Florence, Florence (Italy)

    2011-12-15

    Purpose. - To assess the potential dosimetric gain of pre-segmentation modulated radiotherapy (OAPS, DosiSoft{sup TM}) of breast, compared to routine 3D conformal radiotherapy. Patients and methods. - Twenty patients treated with conservative surgery for breast cancer (9 right and 11 left sided) with various breast volume (median 537 cm{sup 3}; range [100-1049 cm{sup 3}]) have been selected. For each patient, we have delineated a breast volume and a compensation volume (target volumes), as well as organs at risk (lungs and heart). Two treatment plans have been generated: one using the routine 3D conformal technique and the other with the pre-segmentation algorithm of DosiSoft{sup TM} (OAPS). The dose distribution were analyzed using the conformity index for target volumes, mean dose and V 30 Gy for the heart, and mean dose, V 20 Gy and V 30 Gy for lungs. Results. - Over the 20 patients, the conformity index increased from 0.897 with routine technique to 0.978 with OAPS (P < 0,0001). For heart and lung, OAPS decreased irradiation (mean cardiac dose 1,3 vs 1,6 Gy [P < 0,0001] and pulmonary V 20 Gy 6,6 vs 7,1 [P < 0,0001]). Conclusion. - OAPS (DosiSoft{sup TM}) is an original method of segmentation of breast. It is automatic, fast and easy, and is able to increase the conformity index, while sparing organ at risk. (authors)

  10. Monte Carlo Treatment Planning for Advanced Radiotherapy

    DEFF Research Database (Denmark)

    Cronholm, Rickard

    This Ph.d. project describes the development of a workflow for Monte Carlo Treatment Planning for clinical radiotherapy plans. The workflow may be utilized to perform an independent dose verification of treatment plans. Modern radiotherapy treatment delivery is often conducted by dynamically...... modulating the intensity of the field during the irradiation. The workflow described has the potential to fully model the dynamic delivery, including gantry rotation during irradiation, of modern radiotherapy. Three corner stones of Monte Carlo Treatment Planning are identified: Building, commissioning...... and validation of a Monte Carlo model of a medical linear accelerator (i), converting a CT scan of a patient to a Monte Carlo compliant phantom (ii) and translating the treatment plan parameters (including beam energy, angles of incidence, collimator settings etc) to a Monte Carlo input file (iii). A protocol...

  11. Estimating the Risks of Breast Cancer Radiotherapy

    DEFF Research Database (Denmark)

    Taylor, Carolyn; Correa, Candace; Duane, Frances K

    2017-01-01

    Purpose Radiotherapy reduces the absolute risk of breast cancer mortality by a few percentage points in suitable women but can cause a second cancer or heart disease decades later. We estimated the absolute long-term risks of modern breast cancer radiotherapy. Methods First, a systematic literature...... review was performed of lung and heart doses in breast cancer regimens published during 2010 to 2015. Second, individual patient data meta-analyses of 40,781 women randomly assigned to breast cancer radiotherapy versus no radiotherapy in 75 trials yielded rate ratios (RRs) for second primary cancers...... and cause-specific mortality and excess RRs (ERRs) per Gy for incident lung cancer and cardiac mortality. Smoking status was unavailable. Third, the lung or heart ERRs per Gy in the trials and the 2010 to 2015 doses were combined and applied to current smoker and nonsmoker lung cancer and cardiac mortality...

  12. Multi-scale model of the ionosphere from the combination of modern space-geodetic satellite techniques - project status and first results

    Science.gov (United States)

    Schmidt, M.; Hugentobler, U.; Jakowski, N.; Dettmering, D.; Liang, W.; Limberger, M.; Wilken, V.; Gerzen, T.; Hoque, M.; Berdermann, J.

    2012-04-01

    Near real-time high resolution and high precision ionosphere models are needed for a large number of applications, e.g. in navigation, positioning, telecommunications or astronautics. Today these ionosphere models are mostly empirical, i.e., based purely on mathematical approaches. In the DFG project 'Multi-scale model of the ionosphere from the combination of modern space-geodetic satellite techniques (MuSIK)' the complex phenomena within the ionosphere are described vertically by combining the Chapman electron density profile with a plasmasphere layer. In order to consider the horizontal and temporal behaviour the fundamental target parameters of this physics-motivated approach are modelled by series expansions in terms of tensor products of localizing B-spline functions depending on longitude, latitude and time. For testing the procedure the model will be applied to an appropriate region in South America, which covers relevant ionospheric processes and phenomena such as the Equatorial Anomaly. The project connects the expertise of the three project partners, namely Deutsches Geodätisches Forschungsinstitut (DGFI) Munich, the Institute of Astronomical and Physical Geodesy (IAPG) of the Technical University Munich (TUM) and the German Aerospace Center (DLR), Neustrelitz. In this presentation we focus on the current status of the project. In the first year of the project we studied the behaviour of the ionosphere in the test region, we setup appropriate test periods covering high and low solar activity as well as winter and summer and started the data collection, analysis, pre-processing and archiving. We developed partly the mathematical-physical modelling approach and performed first computations based on simulated input data. Here we present information on the data coverage for the area and the time periods of our investigations and we outline challenges of the multi-dimensional mathematical-physical modelling approach. We show first results, discuss problems

  13. Perspectives in absorbed dose metrology with regard to the technical evolutions of external beam radiotherapy; Perspectives en metrologie de la dose face aux evolutions techniques de la radiotherapie externe

    Energy Technology Data Exchange (ETDEWEB)

    Chauvenet, B.; Bordy, J.M. [CEA Saclay, Lab. National Henri Becquerel (LNE-LNHB), 91 - Gif-sur-Yvette (France); Barthe, J. [CEA Saclay (LIST), 91 - Gif-sur-Yvette (France)

    2009-07-01

    This paper presents several R and D axes in absorbed close metrology to meet the needs resulting from the technical evolutions of external beam radiotherapy. The facilities in operation in France have considerably evolved under the impulse of the plan Cancer launched in 2003: replacements and increase of the number of accelerators, substitution of accelerators for telecobalt almost completed and acquisition of innovative facilities for tomo-therapy and stereotaxy. The increasing versatility of facilities makes possible the rapid evolution of treatment modalities, allowing to better delimit irradiation to tumoral tissues and spare surrounding healthy tissues and organs at risk. This leads to a better treatment efficacy through dose escalation. National metrology laboratories must offer responses adapted to the new need, i.e. not restrict themselves to the establishment of references under conventional conditions defined at international level, contribute to the improvement of uncertainties at all levels of reference transfer to practitioners: primary measurements under conditions as close as possible to those of treatment, characterization of transfer and treatment control dosimeters., metrological validation of treatment planning tools... Those axes have been identified as priorities for the next years in ionizing radiation metrology at the European level and included in the European. Metrology Research Programme. A project dealing with some of those topics has been selected in the frame of the Eranet+ Call EMRP 2007 and is now starting. The LNE-LAM is strongly engaged in it. (authors)

  14. Large field radiotherapy

    International Nuclear Information System (INIS)

    Vanasek, J.; Chvojka, Z.; Zouhar, M.

    1984-01-01

    Calculations may prove that irradiation procedures, commonly used in radiotherapy and represented by large-capacity irradiation techniques, do not exceed certain limits of integral doses with favourable radiobiological action on the organism. On the other hand integral doses in supralethal whole-body irradiation, used in the therapy of acute leukemia, represent radiobiological values which without extreme and exceptional further interventions and teamwork are not compatible with life, and the radiotherapeutist cannot use such high doses without the backing of a large team. (author)

  15. Microplanar beams for radiotherapy

    International Nuclear Information System (INIS)

    Company, F.Z.; Allen, B.J.

    1996-01-01

    Recent advances in synchrotron generated X-ray beams with high fluence rate permit the investigation of the application of an array of closely spaced, parallel or converging microbeams in radiotherapy. The proposed technique takes advantage of the hypothesised repair mechanism of capillary cells between alternate microbeam zones, which replaces the lethally irradiated endothelial cells. In this study using the Monte Carlo method, the lateral and depth dose of a single planar microbeam of 100 keV in a tissue/lung/tissue phantom is investigated. Poster 195. (author)

  16. Prone Hypofractionated Whole-Breast Radiotherapy Without a Boost to the Tumor Bed: Comparable Toxicity of IMRT Versus a 3D Conformal Technique

    Energy Technology Data Exchange (ETDEWEB)

    Hardee, Matthew E.; Raza, Shahzad; Becker, Stewart J.; Jozsef, Gabor; Lymberis, Stella C. [Department of Radiation Oncology, New York University School of Medicine, New York, NY (United States); Hochman, Tsivia; Goldberg, Judith D. [Division of Biostatistics, New York University School of Medicine, New York, NY (United States); DeWyngaert, Keith J. [Department of Radiation Oncology, New York University School of Medicine, New York, NY (United States); Formenti, Silvia C., E-mail: silvia.formenti@nyumc.org [Department of Radiation Oncology, New York University School of Medicine, New York, NY (United States)

    2012-03-01

    Purpose: We report a comparison of the dosimetry and toxicity of three-dimensional conformal radiotherapy (3D-CRT) vs. intensity-modulated radiotherapy (IMRT) among patients treated in the prone position with the same fractionation and target of the hypofractionation arm of the Canadian/Whelan trial. Methods and Materials: An institutional review board-approved protocol identified a consecutive series of early-stage breast cancer patients treated according to the Canadian hypofractionation regimen but in the prone position. Patients underwent IMRT treatment planning and treatment if the insurance carrier approved reimbursement for IMRT; in case of refusal, a 3D-CRT plan was used. A comparison of the dosimetric and toxicity outcomes during the acute, subacute, and long-term follow-up of the two treatment groups is reported. Results: We included 97 consecutive patients with 100 treatment plans in this study (3 patients with bilateral breast cancer); 40 patients were treated with 3D-CRT and 57 with IMRT. IMRT significantly reduced the maximum dose (Dmax median, 109.96% for 3D-CRT vs. 107.28% for IMRT; p < 0.0001, Wilcoxon test) and improved median dose homogeneity (median, 1.15 for 3D-CRT vs. 1.05 for IMRT; p < 0.0001, Wilcoxon test) when compared with 3D-CRT. Acute toxicity consisted primarily of Grade 1 to 2 dermatitis and occurred in 92% of patients. Grade 2 dermatitis occurred in 13% of patients in the 3D-CRT group and 2% in the IMRT group. IMRT moderately decreased rates of acute pruritus (p = 0.03, chi-square test) and Grade 2 to 3 subacute hyperpigmentation (p = 0.01, Fisher exact test). With a minimum of 6 months' follow-up, the treatment was similarly well tolerated in either group, including among women with large breast volumes. Conclusion: Hypofractionated breast radiotherapy is well tolerated when treating patients in the prone position, even among those with large breast volumes. Breast IMRT significantly improves dosimetry but yields only a modest

  17. Three-dimensional radiotherapy planning system for esophageal tumors: comparison of treatment techniques and analysis of probability of complications; Planejamento tridimensional para radioterapia de tumores de esofago: comparacao de tecnicas de tratamento e analise de probabilidade de complicacoes

    Energy Technology Data Exchange (ETDEWEB)

    Justino, Pitagoras Baskara; Carvalho, Heloisa de Andrade; Ferauche, Debora; Ros, Renato [Sao Paulo Uni., SP (Brazil). Hospital das Clinicas. Instituto de Radioterapia (InRad)]. E-mail: pitagorasb@hotmail.com

    2003-06-01

    Radiotherapy techniques for esophageal cancer were compared using a three-dimensional planning system. We studied the following treatment techniques used for a patient with squamous cell carcinoma of the middle third of the esophagus: two antero-posterior and two latero-lateral parallel opposed fields, three fields ('Y' and 'T'), and four fields ('X'). Dose-volume histograms were obtained considering spinal cord and lungs as organs at risk. Analysis was performed comparing doses in these organs as recommended by the Normal Tissue Complication Probability (NTCP) and Tumor Control Probability (TCP). When only the lungs were considered the best technique was two antero-posterior parallel opposed fields. The spinal cord was best protected using latero-lateral fields. We suggest the combination of at least two treatment techniques: antero-posterior fields with 'Y' or 'T' techniques, or latero-lateral fields in order to balance the doses in the lungs and the spinal cord. Another option may be the use of any of the three-field techniques during the whole treatment. (author)

  18. Modern cosmology

    International Nuclear Information System (INIS)

    Zeldovich, Y.B.

    1983-01-01

    This paper fives a general review of modern cosmology. The following subjects are discussed: hot big bang and periodization of the evolution; Hubble expansion; the structure of the universe (pancake theory); baryon asymmetry; inflatory universe. (Auth.)

  19. Radiotherapy for treatment of bursitis. Indication, technique, own results, literature survey; Strahlentherapie bei der Periarthropathia humeroscapularis (PHS). Indikation, Technik, eigene Ergebnisse, Literaturuebersicht

    Energy Technology Data Exchange (ETDEWEB)

    Heyd, R. [Staedtische Kliniken Offenbach am Main (Germany). Strahlenklinik]|[Frankfurt Univ. (Germany). Klinik fuer Strahlentherapie und Onkologie; Schopohl, B.; Boettcher, H.D. [Frankfurt Univ. (Germany). Klinik fuer Strahlentherapie und Onkologie

    1998-12-31

    Our own experience covers 41 primarily chronic cases. The patients have been irradiated with a telecobalt device with isocentric opposing fields, receiving 4x1.0 Gy within two weeks; 15 patients (36.6%) received a second radiation treatment (8 Gy), and one patient (2.4%) a third (12 Gy). After a follow-up period of 44 months on the average, the results were: Complete remittence of pain in 44%, abatement of pain in 44%, and no effect in 12%. Improvement of shoulder joint motility was achieved in 78%. The rate of recidivation was as low as 3%. A statistical evaluation of data acquired revealed that the prognosis is worst in case of a long period of pain preceding commencement of radiotherapy, combined with intensive prior therapy. (orig./CB) [Deutsch] In einer eigenen Untersuchung wurden 41 ueberwiegend chronische Faelle mit 4x1,0 Gy in 2 Wochen an einem Telekobaltgeraet mit isozentrischen Gegenfeldern behandelt, 15 (36,6%) erhielten eine 2. Bestrahlungsserie (8 Gy), ein Fall (2,4%) eine Dritte (12 Gy). Nach einem Nachbeobachtungszeitraum von median 44 Monaten fand sich bei 44% eine komplette Schmerzremission, bei 44% eine Linderung und 12% waren ohne einen Einfluss der Behandlung. Eine Verbesserung der Motilitaet des Schultergelenkes wurde bei 78% erreicht. Die Rezidivrate lag bei nur 3%. Nach statistischer Bearbeitung der Daten erwies sich die Kombination einer langen Beschwerdedauer vor Einleitung der Radiotherapie und intensiver Vortherapie als prognostisch unguenstiger (p=0,02). (orig.)

  20. Dosimetry in radiotherapy. V.1

    International Nuclear Information System (INIS)

    1988-01-01

    A series of symposia on dosimetry in medicine and biology have been held by the IAEA in co-operation with WHO. The present symposium was the first one focusing on ''Dosimetry in Radiotherapy''. The papers presented reflected the different steps in the calibration chain such as the calibration standards established by the National Standards Laboratories and the conversion of the reading of calibrated instruments to the desired quantity, i.e. absorbed dose to water at a reference point in the user's beam at the radiotherapy clinic. The programme further examined the procedures necessary for optimization of the treatment of the patient, such as treatment planning methods, dose distribution studies, new techniques of dose measurement, improvements in the physical dose distributions/conformation therapy and special problems involved in total body treatments. Results of quality assurance in radiotherapy were presented from local hospitals as well as from national and international studies. Refs, figs and tabs

  1. Computerised tomography in radiotherapy planning

    International Nuclear Information System (INIS)

    Badcock, P.C.

    1983-01-01

    This study evaluates the effectiveness of computed tomography as an adjunct to radiotherapy planning. Until recently, acquisition of accurate data concerning tumour anatomy lagged behind other developments in radiotherapy. With the advent of computer-tomography (CT), these data can be displayed and transmitted to a treatment planning computer. It is concluded that the greatest inaccuracies in the radiation treatment of patients are to be found in both the inadequate delineation of the target volume within the patient and changes in body outline relative to the target volume over the length of the irradiated volume. The technique was useful in various subgroups (pelvic, intra-thoracic and chest-wall tumours) and for those patients being treated palliatively. With an estimated improvement in cure rate of 4.5% and cost-effective factors of between 3.3 and 5, CT-assisted radiotherapy planning appears to be a worthwhile procedure. (orig.)

  2. Palliative radiotherapy. Ranking within an interdisciplinary treatment concept in case of advanced tumor disease

    International Nuclear Information System (INIS)

    Seegenschmiedt, M.H.

    1998-01-01

    Many tumor-induced symptoms can be alleviated by suitable irradiation in a direct, effective and sparing manner. The clinical response amounts to 80% and is independent of tumor histology. Careful diagnosis and accurate localisation of the causes of symptoms as well as exact therapy planning and execution are required. Based on individual dose planning harmonising single dosis and total dosis, pin-pointed definition of target areas, and application of modern planning and irradiation techniques, palliative radiotherapy is able to achieve long-term improvement with neglectible side-effects, sometimes within only a few days or weeks. It is a valuable part of a consistant therapy concept that is tailored to the individual needs of a patient, by cooperative action of experts from a variety of medical disciplines, intended to optimize the quality of life of patients, and sometimes may exclude conventional radiotherapy. (orig./CB) [de

  3. Modern Supersymmetry

    International Nuclear Information System (INIS)

    Kulish, Petr P

    2006-01-01

    We have spent more than twenty years applying supersymmetry (SUSY) to elementary particle physics and attempting to find an experimental manifestation of this symmetry. Terning's monograph demonstrates the strong influence of SUSY on theoretical elaborations in the field of elementary particles. It gives both an overview of modern supersymmetry in elementary particle physics and calculation techniques. The author, trying to be closer to applications of SUSY in the real world of elementary particles, is also anticipating the importance of supersymmetry for rigorous study of nonperturbative phenomena in quantum field theory. In particular, he presents the 'exact' SUSY β function using instanton methods, phenomena of anomalies and dualities. Supersymmetry algebra is introduced by adding two anticommuting spinor generators to Poincare algebra and by presenting massive and massless supermultiplets of its representations. The author prefers to use mostly the component description of field contents of the theories in question rather than the superfield formalism. Such a style makes the account closer to physical characteristics. Relations required by SUSY among β functions of the gauge, Yukawa and quartic interactions are checked by direct calculations as well as to all orders in perturbation theory, thus demonstrating that SUSY survives quantization. A discussion is included of the hierarchy problem of different scales of weak and strong interactions and its possible solution by the minimal supersymmetric standard model. Different SUSY breaking mechanisms are presented corresponding to a realistic phenomenology. The monograph can also be considered as a guide to 'duality' relations connecting different SUSY gauge theories, supergravities and superstrings. This is demonstrated referring to the particular properties and characteristics of these theories (field contents, scaling dimensions of appropriate operators etc). In particular, the last chapter deals with the Ad

  4. General principles of radiotherapy

    International Nuclear Information System (INIS)

    Easson, E.C.

    1985-01-01

    The daily practice of any established branch of medicine should be based on some acceptable principles. This chapter is concerned with the general principles on which the radiotherapy of the Manchester school is based. Though many radiotherapists in other centres would doubtless accept these principles, there are sufficiently wide differences in practice throughout the world to suggest that some therapists adhere to a fundamentally different philosophy. The authors believe it is important, especially for those beginning their formal training in radiotherapy, to subscribe to an internally consistent school of thought, employing methods of treatment for each type of lesion in each anatomical site that are based on accepted principles and subjected to continuous rigorous scrutiny to test their effectiveness. Not only must each therapeutic technique be evaluated, but the underlying principles too must be questioned if and when this seems indicated. It is a feature of this hospital that similar lesions are all treated by the same technique, so long as statistical evidence justifies such a policy. All members of the staff adhere to the accepted policy until or unless reliable reasons are adduced to change this policy

  5. Radiotherapy of bronchogenic carcinoma

    International Nuclear Information System (INIS)

    Heilmann, H.P.

    1982-01-01

    Radiotherapy of branchogenic carcinoma comprises; palliative treatment, postoperative or pre-operative radiotherapy, radiotherapy as part of a combination of chemotherapy and radiotherapy of small cell carcinoma and curative radiotherapy of non-operable non-small cell carcinoma. Atelectasis and obstruction are indications for palliative radiotherapy. Postoperative radiotherapy is given only in cases of incomplete resection or mediastinal metastases. In the treatment of small cell carcinoma by combined irradiation and chemotherapy the mediastinum and primary tumour are irradiated, generally after chemotherapy, and the C.N.S. receives prophylactic radiotherapy. Curative radiotherapy is indicated in cases of non-operable small cell carcinoma. Irradiation with doses of 60-70 Gy produced 5-years-survival rates of 10-14% in cases classified as T 1 -T 2 N 0 M 0 . (orig.) [de

  6. Locoregional post-mastectomy radiotherapy for breast cancer: literature review

    International Nuclear Information System (INIS)

    Noel, G.; Mazeron, J.J.

    2000-01-01

    Postoperative radiotherapy is controversial after radical mastectomy. Recent clinical trials have shown an increase in survival with this irradiation and conclusions of previous meta-analyses should be reconsidered and conclusions of previous meta-analyses should be reconsidered. The results of a large number of randomized clinical trials in which women received post-mastectomy radiotherapy or not have been renewed. These trials showed a decrease in locoregional failure with the use of postoperative radiotherapy but survival advantages have not been clearly identified. A large number of randomized clinical trials compared postoperative radiotherapy alone, chemotherapy alone and the association of the two treatments. They showed that chemotherapy was less active locally than radiotherapy and that radiotherapy and chemotherapy significantly increased both disease-free and overall survival rates in the groups which received postoperative radiotherapy. These favourable results were, however, obtained with optimal radiotherapy techniques and a relative sparing of lung tissue and cardiac muscle. Many retrospective clinical analyses concluded that results obtained in locoregional failure rate were poor and that these failures led to an increase in future risks. Both radiotherapy and systemic treatment should be delivered after mastectomy, reserved for patients with a high risk of with a diameter ≥ 5 cm. However, radiotherapy could produce secondary effects, and techniques of radiotherapy should be optimal. (author)

  7. Anatomical imaging for radiotherapy

    International Nuclear Information System (INIS)

    Evans, Philip M

    2008-01-01

    The goal of radiation therapy is to achieve maximal therapeutic benefit expressed in terms of a high probability of local control of disease with minimal side effects. Physically this often equates to the delivery of a high dose of radiation to the tumour or target region whilst maintaining an acceptably low dose to other tissues, particularly those adjacent to the target. Techniques such as intensity modulated radiotherapy (IMRT), stereotactic radiosurgery and computer planned brachytherapy provide the means to calculate the radiation dose delivery to achieve the desired dose distribution. Imaging is an essential tool in all state of the art planning and delivery techniques: (i) to enable planning of the desired treatment, (ii) to verify the treatment is delivered as planned and (iii) to follow-up treatment outcome to monitor that the treatment has had the desired effect. Clinical imaging techniques can be loosely classified into anatomic methods which measure the basic physical characteristics of tissue such as their density and biological imaging techniques which measure functional characteristics such as metabolism. In this review we consider anatomical imaging techniques. Biological imaging is considered in another article. Anatomical imaging is generally used for goals (i) and (ii) above. Computed tomography (CT) has been the mainstay of anatomical treatment planning for many years, enabling some delineation of soft tissue as well as radiation attenuation estimation for dose prediction. Magnetic resonance imaging is fast becoming widespread alongside CT, enabling superior soft-tissue visualization. Traditionally scanning for treatment planning has relied on the use of a single snapshot scan. Recent years have seen the development of techniques such as 4D CT and adaptive radiotherapy (ART). In 4D CT raw data are encoded with phase information and reconstructed to yield a set of scans detailing motion through the breathing, or cardiac, cycle. In ART a set of

  8. Italian Modernities

    DEFF Research Database (Denmark)

    Thomassen, Bjørn; Forlenza, Rosario

    assumptions that have substituted for thought and that have perpetuated prejudices both within and outside Italy’s borders. Grounded in meticulous historical and ethnological research, Italian Modernities deserves as wide an audience as its scholarship is deep.” (Michael Herzfeld, Ernest E. Monrad Professor...

  9. Montreal Modern

    DEFF Research Database (Denmark)

    Handberg, Kristian

    2015-01-01

    , and the space age modernism of the 1960s following the Expo 67 and Quebec’s Quiet Revolution. This is reflected in the city’s thriving retro culture through the study of two groups of retro shops. In circulating specific memories and objects in a specific context, retro is an important negotiation of the past...

  10. Advances in radiotherapy

    International Nuclear Information System (INIS)

    Mackie, T.R.

    2005-01-01

    computer optimization to determine optimal beam delivery intensity maps in order to maximize the target coverage and spare critical tissues as much as possible. The intensity modulated beams are delivered by conventional multileaf collimators or binary collimators modulating fan beams delivered rotationally. IMRT can enable higher doses to be delivered to the tumor and/or reduce the complications of sensitive tissues. Variability in the setup of the patient and movement of organs has likely limited the success of radiation therapy in the past but has become critical with the newfound ability of IMRT to put high dose gradients between the tumor and critical tissues. These issues are now being addressed with imaging systems present in the treatment room. Image-guided radiation therapy (IGRT) includes methods, such as transabdominal ultrasound and in-room CT scanners to image the patient just before treatment to improve setup accuracy and methods such as electronic x-ray imaging systems viewing implanted markers during treatment to minimize the effect of organ motion. 18 Excluding proton radiotherapy, equipment costs of modern radiotherapy are only marginally greater than for conventional radiotherapy. In the developed world the cost of radiotherapy equipment is about 15-20% of the total to deliver the treatment. Moreover, the cost of radiation therapy delivery represents only about 10-15% of the budget of a comprehensive cancer center and so it is a bargain as compared to other therapy forms such as surgery and chemotherapy. (author)

  11. Bystander effects and radiotherapy.

    Science.gov (United States)

    Marín, Alicia; Martín, Margarita; Liñán, Olga; Alvarenga, Felipe; López, Mario; Fernández, Laura; Büchser, David; Cerezo, Laura

    2015-01-01

    Radiation-induced bystander effects are defined as biological effects expressed after irradiation by cells whose nuclei have not been directly irradiated. These effects include DNA damage, chromosomal instability, mutation, and apoptosis. There is considerable evidence that ionizing radiation affects cells located near the site of irradiation, which respond individually and collectively as part of a large interconnected web. These bystander signals can alter the dynamic equilibrium between proliferation, apoptosis, quiescence or differentiation. The aim of this review is to examine the most important biological effects of this phenomenon with regard to areas of major interest in radiotherapy. Such aspects include radiation-induced bystander effects during the cell cycle under hypoxic conditions when administering fractionated modalities or combined radio-chemotherapy. Other relevant aspects include individual variation and genetics in toxicity of bystander factors and normal tissue collateral damage. In advanced radiotherapy techniques, such as intensity-modulated radiation therapy (IMRT), the high degree of dose conformity to the target volume reduces the dose and, therefore, the risk of complications, to normal tissues. However, significant doses can accumulate out-of-field due to photon scattering and this may impact cellular response in these regions. Protons may offer a solution to reduce out-of-field doses. The bystander effect has numerous associated phenomena, including adaptive response, genomic instability, and abscopal effects. Also, the bystander effect can influence radiation protection and oxidative stress. It is essential that we understand the mechanisms underlying the bystander effect in order to more accurately assess radiation risk and to evaluate protocols for cancer radiotherapy.

  12. Imaging and concomitant dose in radiotherapy

    International Nuclear Information System (INIS)

    Negi, P.S.

    2008-01-01

    Image guidance in radiotherapy now involves multiple imaging procedures for planning, simulation, set-up inter and intrafraction monitoring. Presently ALARA (i.e. as low as reasonable achievable) is the principle of management of dose to radiation workers and patients in any diagnostic imaging procedures including image guided surgery. The situation is different in repeated radiographic/fluoroscopic imaging performed for simulation, dose planning, patient positioning and set-up corrections during preparation/execution of Image guided radiotherapy (IGRT) as well as for Intensity Modulated Radiotherapy (IMRT). Reported imaging and concomitant doses will be highlighted and discussed for the management and optimization of imaging techniques in IMRT and IGRT

  13. Irradiation of head-and-neck tumors with intensity modulated radiotherapy (IMRT). Comparison between two IMRT techniques with 3D conformal irradiation

    International Nuclear Information System (INIS)

    Heeger, Jonas

    2013-01-01

    For 12 patients with inoperable head-neck carcinoma that were treated with 3D conformal irradiation techniques additional irradiation plans using IMRT were developed. It was shown that the IMRT techniques are superior to the 3D conformal technique. The new rapid arc technique is unclear with respect to the critical organs (parotid glands, spinal canal and mandibles) but is significantly advantageous for the other normal tissue with respect to conformity (steeper dose gradients) and thus radiation dose reduction. The resulting lower irradiation time and the reduced radiation exposure being important for the treatment economy and patients' comfort should favor the more planning intensive rapid arc technique.

  14. Radiation therapy for early stage seminoma of testis. Analysis of survival and gastrointestinal toxicity in patients treated with modern megavoltage techniques over 10 years

    International Nuclear Information System (INIS)

    Yeoh, E.; O'Brein, P.C.; Razali, M.

    1993-01-01

    Seventy-seven patients treated with megavoltage irradiation to the paraaortic and/or pelvic nodal areas, for stage I and non-bulky ( 34 years), stage (I vs II) and dose of radiation (≤ 30 Gy vs > 30 Gy), showed none of these variables to have a significant influence on overall survival or on the incidence of late complications. The results of these findings are discussed in the light of recent studies of a surveillance policy following orchidectomy for stage I seminoma of the testis. Given that gastrointestinal toxicity is the major toxicity associated with the treatment of stage I patients, the data from this study should assist clinicians and their patients to arrive at an informed decision regarding adjuvant radiotherapy. 15 refs., 1 tab., 2 figs

  15. Practical application of the tool calculation Monte Carlo MCVerif for checking for radiotherapy treatment

    International Nuclear Information System (INIS)

    Laliena Bielsa, V. M.; Garcia Romero, A.; Villa Gazulla, D.; Ortega Pardilla, P.; Calvo Carrillo, S.; Millan Cebrian, E.; Hernandez Vitorial, A.; Canellas Aznoz, M.

    2013-01-01

    The object of this work is to verify a patient group representative of the usual techniques of 3D conformal radiotherapy and IMRT performed in the radiotherapy service our hospital and thus validate the algorithm used commercial planning system. (Author)

  16. National arrangements for radiotherapy

    International Nuclear Information System (INIS)

    2007-01-01

    After a presentation of several letters exchanged between the French health ministry and public agencies in charge of public health or nuclear safety after a radiotherapy accident in Epinal, this report comments the evolution of needs in cancerology care and the place given to radiotherapy. It outlines the